Monday, September 28, 2020

Define ACS clinically

 

Q: Clinically, Abdominal Compartment Syndrome (ACS) can be defined as Intra Abdominal Hypertension (IAH) induced new organ dysfunction without a strict intra-abdominal pressure (IAP) threshold? (select one)

A) True
B) False


Answer: A

Abdominal compartment syndrome (ACS) is a tricky business! Experts recommend different definitions for research and clinical purposes. 

For research reasons, ACS is defined as a sustained IAP above 20 mm Hg, with or without Abdominal Perfusion Pressure (APP) less than 60 mm Hg which is associated with new organ dysfunction. Formula for APP 

APP = MAP - IAP 

MAP = Mean arterial pressure 

Clinically there is no intra-abdominal pressure threshold and can be defined as IAH-induced new organ dysfunction without a strict intra-abdominal pressure threshold. Studies failed to correlate and predict intra-abdominal pressure with the diagnosis of ACS.

#surgical-critical-care


References:

1. Malbrain ML, Cheatham ML, Kirkpatrick A, et al. Results from the International Conference of Experts on Intra-abdominal Hypertension and Abdominal Compartment Syndrome. I. Definitions. Intensive Care Med 2006; 32:1722. 

2.  Sugrue M. Abdominal compartment syndrome. Curr Opin Crit Care 2005; 11:333. 

3.  Malbrain ML, Deeren D, De Potter TJ. Intra-abdominal hypertension in the critically ill: it is time to pay attention. Curr Opin Crit Care 2005; 11:156. 

4. Cheatham ML, White MW, Sagraves SG, et al. Abdominal perfusion pressure: a superior parameter in the assessment of intra-abdominal hypertension. J Trauma 2000; 49:621.

Sunday, September 27, 2020

Pregnancy and PRCA

Q: Pregnancy related Pure Red Cell Aplasia (PRCA) usually resolves with delivery? (select one)

A) True

B) False


Answer: A

PRCA associated with pregnancy usually gets resolved within weeks of delivery. Outcomes of such pregnancies are usually good if anemia can be kept under control with transfusion. Steroids have been tried with mixed results. One diagnostic feature is the occurrence of anemia early in pregnancy. Interestingly it can occur in any pregnancy and may or may not relapse in subsequent pregnancies. Importantly, diagnosis should not be confused with aplastic anemia of pregnancy which has relatively a poor outcome.  

#hematology

#Ob-Gyn


References: 

1.  Choudry MA, Moffett BK, Laber DA. Pure red-cell aplasia secondary to pregnancy, characterization of a syndrome. Ann Hematol 2007; 86:233. 

2.  Kashyap R, Pradhan M. Maternal and fetal outcome in pregnancy-associated pure red cell aplasia. J Obstet Gynaecol 2010; 30:733. 

3.  Baker RI, Manoharan A, De Luca E, et al. Pure red cell aplasia of pregnancy: a distinct clinical entity. Br J Haematol. 1983;85(3):619–622. doi: 10.1111/j.1365-2141.1993.tb03359.x. 

4. Oie BK, Hertel J, Seip M, et al. Hydrops fetalis in three infants mother of a mother with acquired chronic pure red cell aplasia: transitory red cell aplasia in one of the infants. Scand J Hematol. 1984;33:466–470. doi: 10.1111/j.1600-0609.1984.tb00726.x.

Saturday, September 26, 2020

HCQ interactions

 Q: Hydroxychloroquine (HCQ) ________ the digoxin level? (select one)

A) increases 

B) decreases


Answer: A

Since HCQ is again popular, the objective of the above question is to highlight the significant and sometimes fatal interaction of HCQ with many important drugs that are used in an inpatient setting. QTc prolongation is well known with many medications and has been discussed well recently in literature with deaths during COVID pandemic (the list can be found somewhere else).

Inpatient hypoglycemia is also a concern when HCQ is used with antidiabetics. In transplant patients, HCQ can increase cyclosporine levels and in cardiac patients, digoxin levels.

#pharmacology


References:

1. Nampoory MR, Nessim J, Gupta RK, Johny KV. Drug interaction of chloroquine with ciclosporin. Nephron 1992; 62:108. 

2. Finielz P, Gendoo Z, Chuet C, Guiserix J. Interaction between cyclosporin and chloroquine. Nephron 1993; 65:333. 

3. Leden I. Digoxin-hydroxychloroquine interaction? Acta Med Scand 1982; 211:411.

4. Chloroquine phosphate USP prescribing information (October 2018) available at US National Library of Medicine DailyMed website available at https://dailymed.nlm.nih.gov/dailymed/getFile.cfm?setid=06c69e2b-211b-4746-9f3a-f86d36520570&type=pdf&name=06c69e2b-211b-4746-9f3a-f86d36520570 (Accessed on September 26, 2020).

Friday, September 25, 2020

ART and lipoatrophy

 Q: Which class of antiretroviral therapy (ART) in HIV patients is more associated with lipoatrophy?

Answer: Nucleoside reverse transcriptase inhibitors (NRTIs) 

 NRTIs are found to be a major culprit associated with lipoatrophy in HIV patients undergoing ART. The thymidine analog, stavudine is found to be most notorious, though zidovudine can do the same. The duration of treatment is directly proportional to the development of lipoatrophy. The thymidine analogs induce inhibition of mitochondrial DNA polymerase gamma and cause mitochondrial toxicity. A biopsy demonstrates mitochondrial DNA depletion, inflammation, and signs of apoptosis.

This side effect has put these ART out of favor for regular use in HIV patients.

#pharmacology

#infectious-diseases


References:

1. Joly V, Flandre P, Meiffredy V, et al. Increased risk of lipoatrophy under stavudine in HIV-1-infected patients: results of a substudy from a comparative trial. AIDS 2002; 16:2447. 

2.  Shlay JC, Sharma S, Peng G, et al. Long-term subcutaneous tissue changes among antiretroviral-naive persons initiating stavudine, zidovudine, or abacavir with lamivudine. J Acquir Immune Defic Syndr 2008; 48:53. 

3.  Shlay JC, Sharma S, Peng G, et al. The effect of individual antiretroviral drugs on body composition in HIV-infected persons initiating highly active antiretroviral therapy. J Acquir Immune Defic Syndr 2009; 51:298. 

Thursday, September 24, 2020

Muscle symptoms in Rhabdomyolysis

 Q: Muscle symptoms are usually prominent in patients with rhabdomyolysis? (select one)

A) True

B) False


Answer: B

Although the classic triad of rhabdomyolysis consists of muscle pain, weakness, and dark urine, more than half of the patients have no muscular symptoms. Malaise, fever, tachycardia, nausea, vomiting, and abdominal pain are more common symptoms. Muscle symptoms, if present, are more pronounced in proximal muscle groups i.e., thighs and shoulders, and in the lower back and calve muscles. Muscle symptoms are usually described by patients as stiffness and cramping.

#muscle-pathology


References:

1. Gabow PA, Kaehny WD, Kelleher SP. The spectrum of rhabdomyolysis. Medicine (Baltimore) 1982; 61:141. 

 2. Huerta-Alardín AL, Varon J, Marik PE. Bench-to-bedside review: Rhabdomyolysis -- an overview for clinicians. Crit Care 2005; 9:158. 

3. Khan FY. Rhabdomyolysis: a review of the literature. Neth J Med 2009; 67:272.

Wednesday, September 23, 2020

Obesity and AF

 Q: Obesity can be protective in atrial fibrillation (AF)? (select one)

A) Yes

B) No


Answer: A

According to the ARIC (Atherosclerosis Risk In Communities) study, 20 percent of AF is due to obesity. One of the objectives of this pearl is to introduce students to the concept of the "obesity paradox'. Interestingly, overweight and obese patients who developed AF tends to have a better prognosis, which includes a lower cardiovascular disease and all-cause mortality, when compared to lean patients with AF. This may be due to the fact that obese people adjust their hemodynamics by remodeling of left atria. Although this remodeling may result in AF but provide some protective effect in comparison to lean patients who develop AF due to other reasons. 

 #cardiology 


 References: 

1. Lavie CJ, Pandey A, Lau DH, et al. Obesity and Atrial Fibrillation Prevalence, Pathogenesis, and Prognosis: Effects of Weight Loss and Exercise. J Am Coll Cardiol 2017; 70:2022. 

2. Huxley RR, Lopez FL, Folsom AR, et al. Absolute and attributable risks of atrial fibrillation in relation to optimal and borderline risk factors: the Atherosclerosis Risk in Communities (ARIC) study. Circulation 2011; 123:1501. 

Tuesday, September 22, 2020

Apheresis in acute pancreatitis due to severe Hyper-TG

 Q: 57 year old male is admitted to ICU with severe abdominal pain and hypotension. Patient is diagnosed with acute pancreatitis secondary to severe hypertriglyceridemia. When apheresis is indicated?

Answer: There are two main modes of treatment in patients who present with severe hypertriglyceridemia-induced pancreatitis (HTGP), apheresis, and intravenous insulin infusion. Either treatment is effective but apheresis should be selected in patients with "the presence of worrisome clinical features". Also, if bedside clinicians feel that the severity of acute pancreatitis is high enough to require therapeutic plasma exchange (TPE)/apheresis. Just on a side note, Heparin has also been described as a treatment in HTGP (see our pearl @ https://bit.ly/3iPGcws)

Worrisome features include 

●Signs of hypocalcemia 

●Lactic acidosis 

 ●Two  or more signs of worsening systemic inflammation i.e., 

  • temperature either more than 38.5°C or less than 35.0°C, 
  • heart rate more than 90 beats/min, 
  • a respiratory rate more than 20 breaths/min or PaCO2 of less than 32 mmHg, 
  • WBC count of more than 12,000 cells/mL, less than 4000 cells/mL, or >10 percent immature (band) forms. 

●Signs of worsening organ dysfunction or multi-organ failure as defined by the Modified Marshall scoring system for organ dysfunction.

#gastro-enterology

#endocrinology 


References:

1. Alagözlü H, Cindoruk M, Karakan T, Unal S. Heparin and insulin in the treatment of hypertriglyceridemia-induced severe acute pancreatitis. Dig Dis Sci 2006; 51:931. 

2.  Jabbar MA, Zuhri-Yafi MI, Larrea J. Insulin therapy for a non-diabetic patient with severe hypertriglyceridemia. J Am Coll Nutr 1998; 17:458. 

3. Mikhail N, Trivedi K, Page C, et al. Treatment of severe hypertriglyceridemia in nondiabetic patients with insulin. Am J Emerg Med 2005; 23:415. 

4. Betteridge DJ, Bakowski M, Taylor KG, et al. Treatment of severe diabetic hypertriglyceridaemia by plasma exchange. Lancet 1978; 1:1368. 

5. Ipe TS, Pham HP, Williams LA 3rd. Critical updates in the 7th edition of the American Society for Apheresis guidelines. J Clin Apher 2018; 33:78.

Monday, September 21, 2020

Splenic artery aneurysm on x-ray

 Q: Why Splenic Artery Aneurysms (SAAs) can sometimes be diagnosed on plain X-ray?


Answer:  Although SAAs are not common still it is the third most common abdominal artery aneurysm, after the aorta and iliac arteries. SAAs are commonly calcified, making them visible on plain x-ray. It is also known as a "Chinese dragon sign". It is more common in pregnant females or women over the age of 50 years. Underlying risk factors are atherosclerosis, portal hypertension, inflammatory conditions, cirrhosis, vascular diseases, and connective tissue disorders. It is a clinically important disorder as rupture can be fatal. 

#surgical-critical-care


References: 

1. Čolović R, Čolović N, Grubor N, Kaitović M. [Symptomatic calcified splenic artery aneurysm: case report]. Srp Arh Celok Lek 2010; 138:760. 

2. Rahmoune FC, Aya G, Biard M, et al. [Splenic artery aneurysm rupture in late pregnancy: a case report and review of the literature]. Ann Fr Anesth Reanim 2011; 30:156. 

3. Lakin RO, Bena JF, Sarac TP, et al. The contemporary management of splenic artery aneurysms. J Vasc Surg 2011; 53:958. 

4. Maillard M, Novellas S, Baudin G, et al. [Splenic artery aneurysm: diagnosis and endovascular therapy]. J Radiol 2010; 91:1103.

Sunday, September 20, 2020

Paraplegia in young healthy after beach vacation

 Q; 32 year old otherwise healthy male admitted to ICU with paraplegia. Patient reports acute back pain during his recent vacation to Miami beach followed by progressive numbness and weakness. Patient denies any drug abuse, sexual encounter, or animal/insect bite/envenomation. MRI showed restricted diffusion in the lower thoracic spinal cord to the conus medullaris. What could be the diagnosis? 


Answer: Surfers' myelopathy

Interestingly surfer's myelopathy often occurs in young people after first time surfing without any known trauma. Clinically progressive lower extremity numbness and weakness is described preceded by acute lower back pain. The cause is not clear but it is speculated that lying prone on the surfboard (lumbar hyperextension) for prolonged periods of time causes the vascular compression leading to eventual myelopathy. MRI shows restricted diffusion in the lower thoracic spinal cord to the conus medullaris. Unfortunately, recovery is not guaranteed.

#neurology


References:

1. Chang CW, Donovan DJ, Liem LK, et al. Surfers' myelopathy: a case series of 19 novice surfers with nontraumatic myelopathy. Neurology 2012; 79:2171. 

2. Lieske J, Cameron B, Drinkwine B, et al. Surfer's myelopathy-demonstrated by diffusion-weighted magnetic resonance imaging: a case report and literature review. J Comput Assist Tomogr 2011; 35:492. 

3. Takakura T, Yokoyama O, Sakuma F, et al. Complete paraplegia resulting from surfer's myelopathy. Am J Phys Med Rehabil 2013; 92:833.


Saturday, September 19, 2020

sarcoidosis and electrolyte abnormality

 Q: 38 year old female with a history of sarcoidosis is admitted to ICU with mental status change after a week of hike in mountains. Which one electrolyte abnormality is expected?


Answer: Hypercalcemia

Hypercalcemia in sarcoidosis gets aggravated by sunlight. High serum calcitriol concentration increases intestinal calcium absorption. There is also a mild component of the calcitriol-induced increase in bone resorption. 

The full description of the pathophysiology of hypercalcemia in sarcoidosis is beyond the scope of  this website but it would be worthy of mentioning a relatively less described phenomenon of Parathyroid hormone-related protein (PTHrP). This protein is well described in the etiology of hypercalcemia in cancer patients but is also found in a majority of biopsies of granulomatous tissue from sarcoid patients.

#electrolyte

#sarcoidosis


References:

1. Adams JS. Vitamin D metabolite-mediated hypercalcemia. Endocrinol Metab Clin North Am 1989; 18:765. 

2. Sharma OP. Vitamin D, calcium, and sarcoidosis. Chest 1996; 109:535.

3. Insogna KL, Dreyer BE, Mitnick M, et al. Enhanced production rate of 1,25-dihydroxyvitamin D in sarcoidosis. J Clin Endocrinol Metab 1988; 66:72. 

4. Zeimer HJ, Greenaway TM, Slavin J, et al. Parathyroid-hormone-related protein in sarcoidosis. Am J Pathol 1998; 152:17.

Friday, September 18, 2020

Palliative care in surgical ICU patients

 Q: Patients who are admitted to Surgical ICU (SICU) for more than a month qualify for palliative care consults? (select one)

A) True

B) False


Answer: A

Patients who are in SICU for more than a month usually have a poor prognosis.

The American College of Surgeons Surgical Palliative Care Task Force recommends palliative care consultation 

 ●When requested by the patient, or their power of attorney (POA) 
 ●If there is a conflict between the care team and the patient/family. 
 ●When an advance directive is already available requesting limited interventions 
 ●Patients hospitalized for more than 30 days 
 ●When care-team believes that life-sustaining treatments are futile

#palliative-care
#surgical-critical-care


References:

1. Bradley CT, Brasel KJ. Developing guidelines that identify patients who would benefit from palliative care services in the surgical intensive care unit. Crit Care Med 2009; 37:946. 

2. Nelson JE, Curtis JR, Mulkerin C, et al. Choosing and using screening criteria for palliative care consultation in the ICU: a report from the Improving Palliative Care in the ICU (IPAL-ICU) Advisory Board. Crit Care Med 2013; 41:2318.

Thursday, September 17, 2020

Ultrasound in ESLD

 Q: 57 year old female is admitted to ICU with sepsis. Patient also found to have severe jaundice and stigmata of liver cirrhosis and End-Stage Liver Disease (ESLD). Patient has no history of alcohol abuse. As you performed bedside ultrasound - liver appears very bright. What does it mean?


Answer: Probable Non-Alcoholic Fatty Liver Disease (NAFLD)

Diffuse fatty infiltration will give a bright appearance to the liver on ultrasound, which is technically described as a hyperechoic texture. This simple bedside procedure when correlated with history, laboratory findings, and other data, can confirm the diagnosis of NFLD with reliable sensitivity and specificity f 85 and 94 percent respectively. Said that liver biopsy is the gold standard to confirm NAFLD.

#hepatology


Reference:

Hernaez R, Lazo M, Bonekamp S, et al. Diagnostic accuracy and reliability of ultrasonography for the detection of fatty liver: a meta-analysis. Hepatology 2011; 54:1082.

Wednesday, September 16, 2020

A-phosphatase in females

 Q: Alkaline phosphatase (AP) levels is physiologically higher in? (select one) 

A) elderly females 

B) younger females


Answer: A

Alkaline phosphatase is an integral part of the liver function test (LFT). But it should be read with caution. Its over-interpretation may lead to unnecessary workup. It should be interpreted in conjunction with other LFT markers, clinical and radiological data. Serum AP comes from the liver and bones. It particularly varies with age like it can be three times higher in children and adolescents due to physiologic osteoblastic activity. Similarly, a healthy elderly female above the age of 65 may have a 50 percent higher AP level than that for a healthy female in 20s or 30s. On the other hand, a healthy female within the third trimester of pregnancy may have a very abnormal AP due to an influx into the maternal blood of placental AP. Another interesting finding is the higher serum AP level in persons with blood types O and B after eating a fatty meal. Similarly, it could be higher than normal in a diabetic patient.

#hepatology

#laboratory-science


Reference:

1. Shipman Kate Elizabeth, Holt Ashley David, Gama Rousseau. Interpreting an isolated raised serum alkaline phosphatase level in an asymptomatic patient BMJ 2013; 346 :f976

2. Nannipieri M, Gonzales C, Baldi S, et al. Liver enzymes, the metabolic syndrome, and incident diabetes: the Mexico City diabetes study. Diabetes Care 2005; 28:1757.

Tuesday, September 15, 2020

myoclonus treatment

 Q: Which of the following is preferred treatment for myoclonus? (select one)

A) Levetiracetam 

 B) Phenytoin


Answer: A

Although historically phenytoin has been used for cortical myoclonus but it can paradoxically exacerbate myoclonus. Special care should be taken on patients who have myoclonus with Unverricht-Lundborg disease, which is progressive myoclonic epilepsy disorder. Also phenytoin can make symptoms worse in palatal myoclonus and cortical-subcortical myoclonus. Levetiracetam is the preffered drug of choice. 

There is a long list of medications which have been tried with various successes including piracetam, brivaracetam, clonazepam, and valproic acid.

#neurology

#pharmacology


References:

1. Lim LL, Ahmed A. Limited efficacy of levetiracetam on myoclonus of different etiologies. Parkinsonism Relat Disord 2005; 11:135.

2. Eldridge R, Iivanainen M, Stern R, et al. "Baltic" myoclonus epilepsy: hereditary disorder of childhood made worse by phenytoin. Lancet 1983; 2:838.

Monday, September 14, 2020

Devic Disease

 Q: 35 year old male with no past medical history is admitted to ICU with an acute attack of bilateral vision loss associated with lower limb weakness, sensory loss, and bladder dysfunction. MRI done in Emergency Department (ED) read as probable Devic Disease. What is Devic disease? 


Answer: Although it is popularly known as Devic Disease, actual nomenclature is Neuromyelitis Optica Spectrum Disorders (NMOSD) or simply neuromyelitis optical (NMO) explains it well. These are the inflammatory disorders of the central nervous system characterized by severe, immune-mediated demyelination and axonal damage predominantly targeting optic nerves and spinal cord. The learning point for this pearl is to highlight that NMOSD is not a variation of multiple sclerosis (MS). It is a distinct disease of its own. It has its own pathogenesis, radiological features, biomarkers, neuropathology, and treatment. 

Attacks can be severe causing optic neuritis and/or myelitis. In contrast to MS, necrosis and cavitation involve both gray and white matter. It is mediated via a humoral immune system whereas MS is mostly a cell-mediated disorder.

#neurology


References:

1. Devic E. Myélite aiguë compliquée de névrite optique. Bull Med (Paris) 1894; 8:1033. 

2. Wingerchuk DM, Lennon VA, Lucchinetti CF, et al. The spectrum of neuromyelitis optica. Lancet Neurol 2007; 6:805. 

3. Ghezzi A, Bergamaschi R, Martinelli V, et al. Clinical characteristics, course and prognosis of relapsing Devic's Neuromyelitis Optica. J Neurol 2004; 251:47. 

4. Kim SH, Kim W, Li XF, et al. Clinical spectrum of CNS aquaporin-4 autoimmunity. Neurology 2012; 78:1179. 

Sunday, September 13, 2020

Prescription of Lasix

 Q: Loop diuretics should always be given as rapid push? (select one)

A) True

B) False


Answer: B

Unfortunately, though loop diuretics are the most prescribed diuretics in ICU, there is less awareness that loop diuretics if given as a rapid push can be very distressing to the patient as can cause transient tinnitus. It can result in ototoxicity if given too fast. Orders should be written with instructions, like for furosemide (the most prescribed one) as 

  •  20 to 40 mg over 5 minutes 
  •  60 to 120 mg over 20 minutes 
  • 160 to 200 mg over 40 to 50 minutes
#pharmacology
#nephrology



References:

1. Rybak LP. Pathophysiology of furosemide ototoxicity. J Otolaryngol. 1982;11(2):127-133. 

2. Kathleen A. Baldwin et al. Acute Sensorineural Hearing Loss: Furosemide Ototoxicity Revisited. Hospital Pharmacy. First Published December 1, 2008 https://doi.org/10.1310/hpj4312-982

3. Brater DC. Diuretic therapy. N Engl J Med 1998; 339:387.

Saturday, September 12, 2020

bubble contrast technique during pericadiocentesis

 Q: How the bubble contrast technique can be applied during pericadiocentesis?

Answer: Bubble contrast study helps in confirming proper needle placement during pericardiocentesis. It is a very vital adjuvant technique to add if procedure is performed emergent at the beside. It helps to confirm no accidental myocardial penetration.

Agitated saline bubble contrast is prepared by rapidly mixing 9 mL of saline with 1 mL of air between two syringes, connected via a three-way stopcock, immediately before injection. Placement of a bedside ultrasound probe is needed while bubble contrast is injected. The layering of contrast outside the heart confirms pericardial localization. If there is a rapid contrast washout or intracardiac swirling varying with the patient's cardiac output, implies probable myocardial perforation. 

Another related technique is to pass smaller diameter guidewire through the needle. It's visualization in pericardium space also implies a safe placement of the needle.

#cardiology
#procedures


References:

1. Ainsworth CD, Salehian O. Echo-guided pericardiocentesis: let the bubbles show the way. Circulation 2011; 123:e210.

2. Osman A, Wan Chuan T, Ab Rahman J, et al. Ultrasound-guided pericardiocentesis: a novel parasternal approach. Eur J Emerg Med 2018; 25:322. 

3. Vayre F, Lardoux H, Pezzano M, et al. Subxiphoid pericardiocentesis guided by contrast two-dimensional echocardiography in cardiac tamponade: experience of 110 consecutive patients. Eur J Echocardiogr 2000; 1:66. 

4.  Weisse AB, Desai RR, Rajihah G, Lopez S. Contrast echocardiography as an adjunct in hemorrhagic or complicated pericardiocentesis. Am Heart J 1996; 131:822. 

Friday, September 11, 2020

postobstructive pulmonary edema

 Q: What are the two types of postobstructive pulmonary edema? 

 Answer: Type I and Type II 

  1. Type I is due to the forceful inspiratory effort in acute airway obstruction, 
  2. Type II is after relief of chronic partial airway obstruction (mostly surgical intervention) 

 Common Type I examples encountered in ICU/emergent setting is 

  •  Postextubation laryngospasm 
  •  Choking/foreign body/Strangulation 
  •  Endotracheal tube obstruction 
  •  Laryngeal tumor/Goitre 
  • Mononucleosis 
  •  Postoperative vocal cord paralysis 
  •  Near drowning 
  •  Intraoperative direct suctioning of endotracheal tube adapter 

 Some examples of Type II are 

  •  Post-tonsillectomy/adenoidectomy 
  •  Post-removal of upper airway tumor 
  •  Hypertrophic redundant uvula

#pulmonary
#ventilator
#trauma
#surgical-critical-care


Reference:

Van Kooy MA, Gargiulo RF. Postobstructive pulmonary edema. Am Fam Physician 2000;62:401–4

Thursday, September 10, 2020

Damping of A lines

 Q: Air bubbles in the arterial line tubing will cause? (select one) 

 A) Under damping of waveforms

 B) Over damping of waveforms


Answer; B

By standard the "fast flush" test should be performed after inserting an arterial line, to test the dynamic response of the monitoring system to pressure. This is performed by quickly opening and closing the valve in the continuous flush device. Normal waveform during 'flushing' is a square wave displacement on the monitor, followed by wiggling and a return to baseline. 

 Air bubbles in the tubing are common and cause over-damping of response. Other causes of overdamped arterial line waveform are overly compliant tubing, kinked catheters, blood clot within the tubing, no fluid, or low flush bag pressure. 

On the other hand, an underdamped waveform is due to excessive tubing lengths, tachycardia, or high output states.

(see reference # 2 for video)

#procedures


References:

Kleinman B, Powell S, Kumar P, Gardner RM. The fast flush test measures the dynamic response of the entire blood pressure monitoring system. Anesthesiology 1992; 77:1215.

2. https://youtu.be/1naupO0IZOQ

Wednesday, September 9, 2020

off label uses of Pregabalin

 Q: Name at least five off label uses of Pregabalin? 

Answer: Pregabalin has been used in inpatient as well as outpatient settings for various reasons. FDA has approved its use for diabetic neuropathic pain, postherpetic neuralgia, as adjunctive therapy for partial-onset seizures in adults, fibromyalgia, and for neuropathic pain associated with spinal cord injury. But it has been found to be useful for various other reasons. Doses should be checked before prescribing for off-label use. 

  • chronic refractory cough 
  • generalized anxiety disorder 
  • postoperative pain 
  • chronic pruritus 
  • restless legs syndrome 
  • social anxiety disorder 
  • vasomotor symptoms associated with menopause  

#pharmacology


References:

1. Vertigan AE, Kapela SL, Ryan NM, Birring SS, McElduff P, Gibson PG. Pregabalin and speech pathology combination therapy for refractory chronic cough: a randomized controlled trial. Chest. 2016;149(3):639-648. doi: 10.1378/chest.15-1271 

2. Baldwin DS, Anderson IM, Nutt DJ, et al. Evidence-based pharmacological treatment of anxiety disorders, post-traumatic stress disorder and obsessive-compulsive disorder: a revision of the 2005 guidelines from the British Association for Psychopharmacology. J Psychopharmacol. 2014;28(5):403-439. doi: 10.1177/0269881114525674. 

3. Chou R, Gordon DB, de Leon-Casasola OA, et al. Management of postoperative pain: a clinical practice guideline from the American Pain Society, the American Society of Regional Anesthesia and Pain Medicine, and the American Society of Anesthesiologists' Committee on Regional Anesthesia, Executive Committee, and Administrative Council [published correction appears in J Pain. 2016;17(4):508-510]. J Pain. 2016;17(2):131-157. doi: 10.1016/j.jpain.2015.12.008 

4. Garcia-Borreguero D, Kohnen R, Silber MH, et al. The long-term treatment of restless legs syndrome/Willis-Ekbom disease: evidence-based guidelines and clinical consensus best practice guidance: a report from the International Restless Legs Syndrome Study Group. Sleep Medicine. 2013;14(7):675-684. doi: 10.1016/j.sleep.2013.05.016 

5. Matsuda KM, Sharma D, Schonfeld AR, Kwatra SG. Gabapentin and pregabalin for the treatment of chronic pruritus. J Am Acad Dermatol. 2016;75(3):619-625.e6. doi: 10.1016/j.jaad.2016.02.1237. 

6. Feltner DE, Liu-Dumaw M, Schweizer E, Bielski R. Efficacy of pregabalin in generalized social anxiety disorder: results of a double-blind, placebo-controlled, fixed-dose study. Int Clin Psychopharmacol. 2011;26(4):213-220. doi: 10.1097/YIC.0b013e32834519bd

7. Nguyen ML. The use of pregabalin in the treatment of hot flashes. Can Pharm J (Ott). 2013;146(4):193-196. doi:10.1177/1715163513490636

Tuesday, September 8, 2020

Treatments of HTGP

 Q: Heparin can be used as a treatment in acute pancreatitis secondary to severe hypertriglyceridemia?

A) True

B) False


Answer: A

Although rarely used and not established as a standard of care (yet) for severe hypertriglyceridemia-induced pancreatitis (HTGP), heparin has an ability to acutely lower the triglyceride. Heparin decreases the triglycerides by stimulating lipoprotein lipase activity, which degrades triglycerides into fatty acids and glycerol. 

Modalities that have been used as a standard of treatment in HTGP are intravenous insulin infusion and Therapeutic Plasma Exchange (TPE).

#endocrinology

#gastroenterology


References:

1. Alagözlü H, Cindoruk M, Karakan T, Unal S. Heparin and insulin in the treatment of hypertriglyceridemia-induced severe acute pancreatitis. Dig Dis Sci 2006; 51:931. 

2. Jain D, Zimmerschied J. Heparin and insulin for hypertriglyceridemia-induced pancreatitis: case report. ScientificWorldJournal 2009; 9:1230. 

3.. Henzen C, Röck M, Schnieper C, Heer K. [Heparin and insulin in the treatment of acute hypertriglyceridemia-induced pancreatitis]. Schweiz Med Wochenschr 1999; 129:1242. 

4. Berger Z, Quera R, Poniachik J, et al. [heparin and insulin treatment of acute pancreatitis caused by hypertriglyceridemia. Experience of 5 cases]. Rev Med Chil 2001; 129:1373.

Monday, September 7, 2020

Salmonella and GI enviroment

Q: H2 blockers are protective against salmonella?

A) True
B) False


Answer: B

The human body has two protective layers against orally acquired infectious agents such as salmonella, one is gastric acidity and the other is normal intestinal microbial flora. 


Any condition or drug which decreases gastric acidity can make infection with salmonella more susceptible. It includes gastric surgery, use of antacids, H2 blockers, proton-pump inhibitors (PPI), and achlorhydric states. Salmonella is a unique pathogen in a way that it already posses the acid tolerance response, which means it has an ability to adapt to a lower pH. Gastric acidity still provides some room for protection. 


The overuse of antibiotics can also make the situation worse. Once and if salmonellae survive in the stomach, it has to compete with the normal intestinal microbial flora. The overuse of antibiotics can take away this protective layer and can cause severe clinical symptoms. Innocent use of prophylactic antibiotics increases this risk among tourists to countries with low community hygiene. 


#infectious-diseases

#gastroenterology


References:


1. Giannella RA, Broitman SA, Zamcheck N. Gastric acid barrier to ingested microorganisms in man: studies in vivo and in vitro. Gut 1972; 13:251. 


2. Neal KR, Briji SO, Slack RC, et al. Recent treatment with H2 antagonists and antibiotics and gastric surgery as risk factors for Salmonella infection. BMJ 1994; 308:176. 

3.  Foster JW. Low pH adaptation and the acid tolerance response of Salmonella typhimurium. Crit Rev Microbiol 1995; 21:215. 

4. Mentzing LO, Ringertz O. Salmonella infection in tourists. Prophylaxis against salmonellosis. Acta Pathol Microbiol Scand 1968; 74:405.

Sunday, September 6, 2020

Mesentric ischemia vessels

 Q: Mesenteric ischemia is more common in which bed of the vessels? (select one) 

A) arterial 

B) venous


Answer: A

Abdominal angina was first described more than a century ago. Logic may argue that passive velocity may be the major cause of mesenteric ischemia but actually, it is arterial embolism which is responsible half of the time (50 percent) for mesenteric ischemia, followed by nonocclusive mesenteric ischemia (20 percent). Arterial and venous thrombosis are equally responsible (15 percent each) for mesenteric ischemia. In fact, mesenteric venous thrombosis has a slower course and lower mortality. The rate of the flow itself doesn't make any difference but the underlying systemic diseases are more responsible for this pathology. It includes age, atherosclerosis, low cardiac output (CHF), atrial fibrillation), cardiac valvular pathologies, and intraabdominal malignancy.

#surgical-critical-care


References:

1. Goodman G H. Angina abdominus. Am J Med Sci. 1918;155:524–528. 

2. Chang R W, Chang J B, Longo W E. Update in management of mesenteric ischemia. World J Gastroenterol. 2006;12:3243–3247. 

3. Cleveland T J, Nawaz S, Gaines P A. Mesenteric arterial ischaemia: diagnosis and therapeutic options. Vasc Med. 2002;7:311–321. 

4. Monita MM, Gonzalez L. Acute Mesenteric Ischemia. [Updated 2020 Jun 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK431068/

Saturday, September 5, 2020

abdominal pain in dka

 Q: Abdominal pain in Diabetic keto-acidosis (DKA) is associated with the severity of the metabolic acidosis? (select one)

A) True

B) False


Answer: A

Abdominal pain is an important clinical indicator in severe hyperglycemic states. 

1. It is very unusual in Hyperosmolar Hyperglycemic State (HHS). Its presence indicates probable DKA. 

2. It correlates with the severity of the metabolic acidosis, but not with the severity of hyperglycemia or dehydration. Severe abdominal pain in DKA speaks of very low serum bicarbonate, may be less than 5 mEq/L). If it continues to persist after acidosis is resolved, than underlying pancreatitis need to be ruled out.

#endocrinology


Reference:

Umpierrez G, Freire AX. Abdominal pain in patients with hyperglycemic crises. J Crit Care. 2002;17(1):63-67. doi:10.1053/jcrc.2002.33030

Friday, September 4, 2020

Colectomy for constipation

Q: 82 year old male is admitted to ICU after colectomy as a last resort for debilitating constipation. These patients usually have unbearable abdominal pain? (select one)

A) True
B) False


Answer: B

Subtotal colectomy with ileorectal anastomosis is used as a last resort for debilitating constipation. Contrary to popular belief, severe abdominal pain due to constipation is a contraindication to this treatment. The reason is being as severe abdominal pain points towards pathology other than just constipation. Secondly, these patients tend to have worsening pain after colectomy. There are five criteria to be fulfilled before surgery is considered as a treatment for constipation. 
  • Constipation should be unresponsive to all viable medical treatments. 
  • Slow colonic transit of the inertia pattern is documented.
  • Intestinal pseudoobstruction is ruled out.
  • Any pelvic floor dysfunction is ruled out.
  • Patient should not have abdominal pain as a presenting symptom.

#surgical-critical-care
#gastroenterology


References:

1. ford SA, Verne GN. Approach to patients with refractory constipation. Curr Gastroenterol Rep 2000; 2:389. 

2. Pikarsky AJ, Singh JJ, Weiss EG, et al. Long-term follow-up of patients undergoing colectomy for colonic inertia. Dis Colon Rectum 2001; 44:179.

Thursday, September 3, 2020

gender predisposition in acute acalculous cholecystitis

 Q: Which gender has more predisposition to have acute acalculous cholecystitis (ACC)? (select one)

A) male

B) female


Answer: A

In contrast to calculous cholecystitis (CC) which is more common in females, acute acalculous cholecystitis has higher male preponderance by 40 to 80 percent. CC in females can be explained by elevated progesterone levels causing biliary stasis but there is no clear explanation of the higher rate of ACC in males, particularly elderly men. This calls for higher vigilance in ICU for sick elderly men with unexplained fever or abdominal pain.

#gastroenterology


References:

1. Barie PS. Acalculous and postoperative cholecystitis. In: Surgical intensive care, Barie PS, Shires GT (Eds), Little Brown & Co, Boston 1993. p.837. 

 2. Ganpathi IS, Diddapur RK, Eugene H, Karim M. Acute acalculous cholecystitis: challenging the myths. HPB (Oxford) 2007; 9:131.

Wednesday, September 2, 2020

QT interval

 Q: The QT interval on EKG is measured from? (select one)

A) start of the QRS complex 

 B) end of the QRS complex 


Answer: A

There are two mistakes usually made while looking into QT interval on EKG. 

1. QT interval should be measured from the beginning of the QRS complex (instead of the end) to the end of the T-wave. It needs to be corrected for the heart rate.

2. If U wave is present it should not be included in the QT interval.

#cardiology


Reference:

Postema PG, Wilde AA. The measurement of the QT interval. Curr Cardiol Rev. 2014;10(3):287-294. doi:10.2174/1573403x10666140514103612

Tuesday, September 1, 2020

RSBI on vent

 Q: If Rapid Shallow Breathing Index (RSBI) is measured while the patient is breathing through a T-piece on ventilator, it would be erroneously? (select one) 

A) lower

B) higher


Answer: A

Any kind of ventilator support such as pressure support, continuous positive airway pressure (CPAP), and even breathing through a T-piece while patient is on a ventilator will erroneously give a lower than actual RSBI. To minimize this error of margin, RSBI should be obtained using a hand-held spirometer attached to the endotracheal tube while a ventilator is on pressure support (PS) of 0 cm H2O and positive end-expiratory pressure (PEEP) of 0 cm H2O, without flow trigger for one minute.

#ventilators


References:

1. El-Khatib MF, Zeineldine SM, Jamaleddine GW. Effect of pressure support ventilation and positive end expiratory pressure on the rapid shallow breathing index in intensive care unit patients. Intensive Care Med 2008; 34:505. 

2. Patel KN, Ganatra KD, Bates JH, Young MP. Variation in the rapid shallow breathing index associated with common measurement techniques and conditions. Respir Care 2009; 54:1462. 

3. Kheir F, Myers L, Desai NR, Simeone F. The effect of flow trigger on rapid shallow breathing index measured through the ventilator. J Intensive Care Med 2015; 30:103. 

4. Desai NR, Myers L, Simeone F. Comparison of 3 different methods used to measure the rapid shallow breathing index. J Crit Care 2012; 27:418.e1.

Monday, August 31, 2020

hypothyroidism and statin-induced myopathy

 Q; Why patients with a history of hypothyroidism are more susceptible to have statin-induced myopathy?

Answer:  There are two suggested mechanisms to explain hypothyroidism related statin-induced myopathy. Hypothyroidism causes dyslipidemia. Most of the statins are lipophilic which leads to statin-induced myopathy. Another reason is the possibility that the use of statins may "unmask" the covert hypothyroid myopathy. It would be wise to treat hypothyroidism prior to initiate statin therapy. Similarly, vitamin D should also be replenished at an appropriate level to decrease the risk of myopathy from the statins. 

#endocrine

#pharmacology


References:

1. al-Jubouri MA, Briston PG, Sinclair D, et al. Myxoedema revealed by simvastatin induced myopathy. BMJ 1994; 308:588. 

2. Khayznikov M, Hemachrandra K, Pandit R, et al. Statin Intolerance Because of Myalgia, Myositis, Myopathy, or Myonecrosis Can in Most Cases be Safely Resolved by Vitamin D Supplementation. N Am J Med Sci 2015; 7:86.  

Sunday, August 30, 2020

TLS ansd diuretics

 Q: Which Diuretic is preferred in patients with Tumor Lysis Syndrome if required? (select one)

A: bumetanide 

B) furosemide 

 

Answer:

 Patients undergoing TLS usually don't require diuretics and intravenous hydration should be enough. But a large number of chemotherapy patients have either cardiac or/and renal dysfunction and may require diuretics to keep urine output (U-OP) 80-100 cc/hour, a usual target of U-OP in TLS. Loop diuretics (furosemide) is preferred as it also helps to reduce the risk of hyperkalemia by increasing potassium excretion. TLS is considered an oncologic emergency. ICU admission is highly desirable. It releases a large amount of potassium, phosphate, and nucleic acids (subsequently converted to uric acid) into the systemic circulation.

#oncology


Reference:

1. Mirrakhimov AE, Voore P, Khan M, Ali AM. Tumor lysis syndrome: A clinical review. World J Crit Care Med. 2015;4(2):130-138. Published 2015 May 4. doi:10.5492/wjccm.v4.i2.130 2. 

2. Howard SC, Jones DP, Pui CH. The tumor lysis syndrome [published correction appears in N Engl J Med. 2018 Sep 13;379(11):1094]. N Engl J Med. 2011;364(19):1844-1854. doi:10.1056/NEJMra0904569

Saturday, August 29, 2020

fluorescence bronchoscopy

 Q; What purpose fluorescence bronchoscopy serves? 

 Answer: Biologically abnormal tissue such as precancerous lesions, particularly squamous cell dysplasias lose their fluorescent property. Auto-fluorescence bronchoscopy (AFB) is used to detect them. It can be used with a regular bronchoscope where a bronchoscope can switch fluorescent and white light modes.

 AFB scopes highlight differences in red and green fluorescence from the tissues. Squamous dysplasia, carcinoma in situ (CIS), and microinvasive carcinoma have much weaker green fluorescence and slightly weaker red fluorescence than normal tissues at a wavelength of 380 to 440 nm (blue spectrum). 

This decrease in florescence activity is probably due to increased epithelial thickness, and neovascularization. AFB is so far has been utilized to identify lesions at risk of progression to invasive squamous cell carcinoma only. Its utility is not much of value for metastatic or adeno carcinomas.  

#procedures

#pulmonary


References:

1. Hung J, Lam S, LeRiche JC, Palcic B. Autofluorescence of normal and malignant bronchial tissue. Lasers Surg Med 1991; 11:99. 

2. Qu J, MacAulay C, Lam S, Palcic B. Mechanisms of ratio fluorescence imaging of diseased tissue. Society of Photo-optical Instrumentation Engineers 1995; 2387:71.

Friday, August 28, 2020

MG and drugs

 Q: Which of the following class of cardiac drugs be used with caution in Myasthenia Gravis (MG)? (select one)

A) Beta Blockers (BB)

B) Calcium Channel Blockers (CCB)


Answer: A

Potentially any drug can exacerbate MG. The most notorious and well known are aminoglycosides, fluoroquinolone, and neuromuscular blocking agents, which are used frequently in ICUs. For clinicians working in ICU, it should be noted that any respiratory depressants like benzodiazepines, opioids, or sedatives can have an exacerbated effect on patients with MG causing unnecessary need for mechanical ventilation. 

Magnesium sulfate is one of the most reflexly ordered electrolyte replacement in ICU, as well as found in many over the counter multi-vitamin bottles. Patients with MG should not be a part of an electrolyte protocol in ICU.

Patients in oncology service/ICU may not be candidates of Programmed cell death 1 (PD-1) inhibitors. They can trigger autoimmune MG. 

 Many patients with MG have simultaneous cardiac diseases. All beta-blockers and procainamide should be used with caution in these patients. These patients can be prescribed statins but with very close monitoring and watching risk/benefit ratio between cardiac and MG risks.


#neurology

#cardiology

#pharmacology


References:

1. A Ahmed, Z Simmons. Drugs Which May Exacerbate or Induce Myasthenia Gravis: A Clinician's Guide. The Internet Journal of Neurology. 2008 Volume 10 Number 

2. Mehrizi M, Fontem RF, Gearhart TR, Pascuzzi RM. Medications and Myasthenia Gravis (A Reference for Health Care Professionals), Indiana University School of Medicine (Department of Neurology), 2012. 

3. Dillon FX. Anesthesia issues in the perioperative management of myasthenia gravis. Semin Neurol 2004; 24:83. 

4. Khalid R, Ibad A, Thompson PD. Statins and Myasthenia Gravis. Muscle Nerve 2016; 54:509.

Thursday, August 27, 2020

acute abdominal pain with forceful evacuation of bowel.

 Q: 65 year old male presented to ED with abdominal pain. Patient described his pain as acute around the periumbilical region, associated with nausea and vomiting. Patient also described his pain first occurs with forceful evacuation of bowel. On exam, patient's pain appears way out of proportion to findings. What could be the probable etiology?


Answer: Acute mesenteric ischemia 

​The clinical exam can be very deceiving in acute mesenteric ischemia and requires a high index of suspicion. In the early stages of presentation, pain is usually way out of proportion to physical findings. Abdominal distension, rebound tenderness, and guarding are relatively late signs. Association with rapid and forceful bowel evacuation should raise a high suspicion especially in males above 60 years of age. Risk factors are advanced age, atherosclerosis, history of smoking, and cardiac disease, particularly atrial fibrillation.

#surgical-critical-care


References:

1. Oldenburg WA, Lau LL, Rodenberg TJ, Edmonds HJ, Burger CD. Acute Mesenteric Ischemia: A Clinical Review. Arch Intern Med. 2004;164(10):1054–1062. doi:10.1001/archinte.164.10.1054

2. Monita MM, Gonzalez L. Acute Mesenteric Ischemia. [Updated 2020 Jun 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK431068/

Wednesday, August 26, 2020

HIV prompt treatment

Q: 44-year-old male is admitted to ICU with sepsis. Patient gets diagnosed with HIV. Prompt treatment of HIV applies to the start of antiretroviral therapy (ART) within which period of time? (select one)

A) same day
B) within three days
C) within a week


Answer: A

Prompt treatment for HIV applies to the initiation of ART on the same day of diagnosis if resources allow. In this regard, the availability of starter packs of an antiretroviral regimen is extremely important. Studies have shown that this approach is associated with higher adherence to treatment, decrease transmission, and most importantly a more rapid time for virologic suppression without major adverse effects. 


#infectious-diseases 


References:

1. Pilcher CD, Ospina-Norvell C, Dasgupta A, et al. The Effect of Same-Day Observed Initiation of Antiretroviral Therapy on HIV Viral Load and Treatment Outcomes in a US Public Health Setting. J Acquir Immune Defic Syndr 2017; 74:44. 


2. United States Department of Health and Human Services. Guidelines for the Use of Antiretroviral Agents in Adults and Adolescents Living with HIV. https://aidsinfo.nih.gov/guidelines/html/1/adult-and-adolescent-arv/0 (Accessed on August 24, 2020).




Tuesday, August 25, 2020

Hyperglycemia in ICU

Q: Hyperglycemic response to dextrose containing fluid infusion in ICU patients is usually exaggerated. What are the reasons behind it?

Answer:  It is not a surprise that infusion of dextrose-containing solutions can cause hyperglycemia, but this response is exaggerated particularly in ICU patients. This is due to two other added mechanisms.

1. counter-regulatory hormone response i.e. increased epinephrine secretion. 
2. cytokine responses

These all combined effect leads to hyperglycemia much higher than expected.


#electrolyte
#endocrine


References:

1. McCowen KC, Malhotra A, Bistrian BR. Stress-induced hyperglycemia. Crit Care Clin 2001; 17:107. 


2. Wolfe RR, Allsop JR, Burke JF. Glucose metabolism in man: responses to intravenous glucose infusion. Metabolism 1979; 28:210.

Monday, August 24, 2020

zones of the retroperitoneum

Q: There are how many zones of the retroperitoneum?

Answer: Three

The retroperitoneum is divided into three zones which are used to describe the location of retroperitoneal hematomas. 

●Zone 1 is the central retroperitoneum, extending from the diaphragm superiorly to the bifurcation of the aorta inferiorly. The aorta, the inferior vena cava, the origins of the renal and major visceral vessels, a portion of the duodenum, and the pancreas lies in this zone. 

●Zone 2 includes both of the lateral perinephric areas of the upper retroperitoneum from the renal vessels medially to the lateral reflection of posterior parietal peritoneum of the abdomen, and extending from the diaphragm superiorly to the level of the aortic bifurcation inferiorly. Zone 2 contains the adrenal glands, the kidneys, the renal vessels, the ureters, and the ascending and descending colon. It is usually not contiguous. 

Zone 3 is inferior to the aortic bifurcation and includes the right and left internal and external iliac arteries and veins, the distal ureter, the distal sigmoid colon, and the rectum.

#trauma



References:


1. Feliciano DV. Management of traumatic retroperitoneal hematoma. Ann Surg 1990; 211:109.


2. Bageacu S, Kaczmarek D, Porcheron J. Conduite à tenir devant un hématome rétro-péritonéal d'origine traumatique [Management of traumatic retroperitoneal hematoma]. J Chir (Paris). 2004;141(4):243-249. doi:10.1016/s0021-7697(04)95603-7

Sunday, August 23, 2020

treatment of achalasia

Q: Out of the following which is considered a relatively effective treatment of achalasia? 

A) isosorbide dinitrate 
B) sildenafil 
C) dicyclomine 
D) terbutaline 
E) theophylline


Answer: A 

 Surgical procedures including botulinum toxin injection remain the mainstay of treatment for achalasia. For patients who are not candidates for this, many pharmacological treatments have been proposed. Out of all, sublingual isosorbide dinitrate 10-15 minutes prior to a meal is considered the most effective. The dose is 5 mg. If isosorbide dinitrate is not available (as in the USA) sublingual nitroglycerin in a dose of 0.4 mg can be used. Side effects are headache and flushing.  

5-phosphodiesterase inhibitors (sildenafil), anticholinergics (atropine, dicyclomine, cimetropium bromide), beta-adrenergic agonists (terbutaline), and theophylline have been tried but so far failed to show any successful results. Short-acting Calcium Channel blockers have been proposed but should be avoided as it can cause hemodynamic collapse.

#surgical-critical-care
#gastroenterology


References:

1. Wen ZH, Gardener E, Wang YP. Nitrates for achalasia. Cochrane Database Syst Rev 2004; :CD002299. 

2. Kahrilas PJ, Pandolfino JE. Treatments for achalasia in 2017: how to choose among them. Curr Opin Gastroenterol 2017; 33:270. 

Saturday, August 22, 2020

Meperidine

Q: Meperidine can have which effect? (select one) 

A) Dysphoria 
B) Euphoria


Answer:

Physicians may get into the cognitive bias that the patients who are requesting meperidine are looking for euphoria. On the contrary, meperidine can cause distressing dysphoria. In ICU it should be used with caution as due to its well-known toxic metabolite normeperidine, which has serotonergic properties, and drug-drug interaction it has a high risk of causing serotonin syndrome and seizure.

#pharmacology


References:

1. Latta KS, Ginsberg B, Barkin RL. Meperidine: a critical review. Am J Ther 2002; 9:53.

2. Yasaei R, Rosani A, Saadabadi A. Meperidine. [Updated 2020 May 18]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470362/

Friday, August 21, 2020

Gabapentin overdose

Q: 52 year old male with Chronic Kidney Disease stage 4 is transferred from medical floor to ICU due to obtundation. There is a suspicion of an overdose of Gabapentin due to drug error on the floor. Patient required intubation for protection of the airway. CT Head reported negative. What is your next line of action?


Answer: Hemodialysis

Gabapentin should be given with caution in patients with renal insufficiency. Actually proper Cockcroft Gault formula should be applied for calculation of the dose. It should be sufficient to give 200 to 300 mg of gabapentin after 4 hours of each hemodialysis session in End-Stage Renal Disease (ESRD) patients if prescribed.


#pharmacology


Reference:

Wong MO, Eldon MA, Keane WF, et al. Disposition of gabapentin in anuric subjects on hemodialysis. J Clin Pharmacol. 1995;35(6):622-626. doi: 10.1002/j.1552-4604.1995.tb05020.x

Thursday, August 20, 2020

MM clinical spectrum

Q: 66 year old male with multiple myeloma (MM) is admitted to ICU with mental status change. Which of the following is more common in patients with MM? (select one)

A) Anemia 
B) Hypercalcemia


Answer: A

The objective of the above question is to emphasize that though hypercalcemia is considered synonymous with MM, there are other abnormalities that may be more common. One of the largest retrospective studies looking into the clinical spectrum of MM was done at Mayo in 2003 counting more than 1000 patients. It found the following frequency

  • Anemia - 73 percent 
  • Bone pain - 58 percent 
  • Elevated creatinine - 48 percent 
  • Fatigue/generalized weakness  - 32 percent 
  • Hypercalcemia -28 percent
  • Weight loss - 24 percent
  • Paresthesias - 5 percent
  • Hepatomegaly - 4 percent
  • Splenomegaly  - 1 percent
  • Lymphadenopathy - 1 percent, and 
  • Fever - 0.7 percent
#hematology
#electrolytes


Reference:

Kyle RA, Gertz MA, Witzig TE, et al. Review of 1027 patients with newly diagnosed multiple myeloma. Mayo Clin Proc 2003; 78:21.




Wednesday, August 19, 2020

wandering spleen

Q: 34 year old soccer player is admitted with acute right-sided abdominal pain. CT scan report described wandering spleen. What is wandering spleen?

Answer: Wandering spleen also known as the ectopic spleen, where spleen migrates to another location in the abdomen. This is due to either laxity or maldevelopment (congenital) of the supporting ligaments. Abdominal pain can be acute, chronic, or intermittent pain. Pain is probably due to the torsion of the wandering spleen. Removal of the spleen is recommended as it may cause life-threatening complications including splenic infarction, portal hypertension, and hemorrhage. Splenopexy has been described but is not preferred as recurrence or complications are common.

#surgical-critical-care


Reference:

1. Gayer G, Hertz M, Strauss S, Zissin R. Congenital anomalies of the spleen. Semin Ultrasound CT MR 2006; 27:358. 


2. Faridi MS, Kumar A, Inam L, Shahid R. Wandering Spleen- A diagnostic Challenge: Case Report and Review of Literature. Malays J Med Sci. 2014;21(6):57-60. 


3. Stringel G, Soucy P, Mercer S. Torsion of the wandering spleen: splenectomy or splenopexy. J Pediatr Surg. 1982;17(4):373–375.

Tuesday, August 18, 2020

BB in VT storm

Q: In patients with electrical storm or incessant Ventricular Tachycardia, along with amiodarone which beta-blocker is preferred? 

A) Metoprolol 
B) Propranolol 


 Answer:

 Beta-blockers reduce the adrenergic surge associated with ventricular tachyarrhythmias (VT-storm) and due to defibrillator shocks. Propranolol which is a nonselective beta-blocker is found to be more effective than beta-1 selective metoprolol. Propranolol is found to terminate VT significantly earlier than metoprolol. Also, it may decrease the incidences of implantable cardioverter-defibrillator (ICD) shocks.


#cardiology



References:


1. Gorenek B, Blomström Lundqvist C, Brugada Terradellas J, et al. Cardiac arrhythmias in acute coronary syndromes: position paper from the joint EHRA, ACCA, and EAPCI task force. Europace 2014; 16:1655.

2. Eifling M, Razavi M, Massumi A. The evaluation and management of electrical storm. Tex Heart Inst J 2011; 38:111.

Monday, August 17, 2020

MTX induced neurotoxicity

Q: 32 year old female is admitted to ICU with seizures after Methotrexate (MTX) treatment. Can MTX can be prescribed to her again in the future? (select one)

A) Yes
B) No


Answer: A

Neurotoxicity due to MTX is common. It can be acute within the first 24 hours, subacute within a week or can be chronic for months and years. It may manifest as somnolence, confusion, or seizures. 
Fortunately, it resolves without sequelae with reversal of changes on MRI. MTX can be given as oral, intravenous (IV), intramuscular (IM) or intrathecal (IT).

#pharmacology

#neurology



References:


1. Bhojwani D, Sabin ND, Pei D, et al. Methotrexate-induced neurotoxicity and leukoencephalopathy in childhood acute lymphoblastic leukemia. J Clin Oncol. 2014;32(9):949-959. doi:10.1200/JCO.2013.53.0808


2. Brugnoletti F, Morris EB, Laningham FH, et al. Recurrent intrathecal methotrexate induced neurotoxicity in an adolescent with acute lymphoblastic leukemia: Serial clinical and radiologic findings. Pediatr Blood Cancer. 2009;52(2):293-295. doi:10.1002/pbc.21764

Sunday, August 16, 2020

CT vs bronch

Q: 58 year old male with a history of HIV is admitted to ICU with hemoptysis. There is a concern for Kaposi sarcoma. Which study would be appropriate to demonstrate it? (select one)

A) Flexible bronchoscopy
B) High-resolution CT (HRCT)


Answer: A

There is a misconception that HRCT can see everything. Bronchoscopy and CT scan both complement each other. CT scans can demonstrate bronchiectasis, aspergillomas, and carcinomas better. On the other hand, bronchoscopy is ideal for subtle mucosal abnormalities such as bronchitis, papillomas, Dieulafoy disease, bronchial carcinoid, and Kaposi sarcoma.

In the case of active hemoptysis, flexible bronchoscopy would be preferred to visualize active bleeding.

#pulmonary



References:


1. Set PA, Flower CD, Smith IE, et al. Hemoptysis: comparative study of the role of CT and fiberoptic bronchoscopy. Radiology 1993; 189:677. 


2. McGuinness G, Beacher JR, Harkin TJ, et al. Hemoptysis: prospective high-resolution CT/bronchoscopic correlation. Chest 1994; 105:1155. 

3. Tak S, Ahluwalia G, Sharma SK, et al. Haemoptysis in patients with a normal chest radiograph: bronchoscopy-CT correlation. Australas Radiol 1999; 43:451.