Nephrotic syndrome and ACS

 Q: Nephrotic syndrome may cause acute compartment syndrome (ACS) of the extremities? (select one)

A) True

B) False

Answer: A

Nephrotic syndrome decreases the serum osmolarity and may result in ACS. There is a long list of non-traumatic causes of ACS. These conditions are hard to differentiate due to concomitant other primary underlying medical pathologies, like ischemia-reperfusion injury, bleeding disorders, chemical DVT prophylaxes, vascular diseases, envenomations, injection of recreational drugs, aggressive IV fluid resuscitation in ICU, poor positioning during surgery or in bed, Group A streptococcus infections of muscle, and post saphenous vein harvesting during heart bypass surgery. These conditions require astute diagnosis and frequently surgical interventions. Please see the reference section for some interesting case reports.

#surgical-critical-care

References:

1. Elliott KG, Johnstone AJ. Diagnosing acute compartment syndrome. J Bone Joint Surg Br 2003; 85:625. . 

2. Kleshinski J, Bittar S, Wahlquist M, et al. Review of compartment syndrome due to group A streptococcal infection. Am J Med Sci 2008; 336:265. 

3. Patel YA, Marzella N. Dietary Supplement-Drug Interaction-Induced Serotonin Syndrome Progressing to Acute Compartment Syndrome. Am J Case Rep 2017; 18:926. 

4. Burnside J, Costello JM Jr, Angelastro NJ, Blankenship J. Forearm compartment syndrome following thrombolytic therapy for acute myocardial infarction. Clin Cardiol 1994; 17:345. 

5. Yip TR, Demaerschalk BM. Forearm compartment syndrome following intravenous thrombolytic therapy for acute ischemic stroke. Neurocrit Care 2005; 2:47. 

6. Roberge RJ, McLane M. Compartment syndrome after simple venipuncture in an anticoagulated patient. J Emerg Med 1999; 17:647. 

7. Mills J, Pretorius V, Lording T, et al. Bilateral anterior compartment syndrome after routine coronary artery bypass surgery and severe hypothyroidism. Ann Thorac Surg 2010; 90:1338. 

8. Kolli A, Au JT, Lee DC, et al. Compartment syndrome after endoscopic harvest of the great saphenous vein during coronary artery bypass grafting. Ann Thorac Surg 2010; 89:271. 

9. O'Connor G, McMahon G. Complications of heroin abuse. Eur J Emerg Med 2008; 15:104. Köstler W, Strohm PC, Südkamp NP. Acute compartment syndrome of the limb. Injury 2004; 35:1221. 

10. Defraigne JO, Pincemail J. Local and systemic consequences of severe ischemia and reperfusion of the skeletal muscle. Physiopathology and prevention. Acta Chir Belg 1998; 98:176.

Fenoldopam and GFR

 Q: Fenoldopam ____________  glomerular filtration rate (GFR)? (select one)

A) increases

B) decreases

Answer: A

Fenoldopam is an anti-hypertensive and a peripheral dopamine-1 receptor agonist. It has an unique advantage of not compromising and many times to increase the renal perfusion. It is a good intravenous infusion of choice to control blood pressure in patients with renal insufficiency. It also increases the urine output. Sodium should be watched carefully as it may increase renal excretion of sodium. Patients can be sensitive in response and should be started at lowest dose at 0.1 mcg/kg per minute, and can be titrated every 15 minutes to the maximum dose of 2.0 mcg/kg per minute.

#hemodynamic

#nephrology

#pharmacology

References:

1. Murphy MB, Murray C, Shorten GD. Fenoldopam: a selective peripheral dopamine-receptor agonist for the treatment of severe hypertension. N Engl J Med 2001; 345:1548. 

2. White WB, Halley SE. Comparative renal effects of intravenous administration of fenoldopam mesylate and sodium nitroprusside in patients with severe hypertension. Arch Intern Med 1989; 149:870. 

3Shusterman NH, Elliott WJ, White WB. Fenoldopam, but not nitroprusside, improves renal function in severely hypertensive patients with impaired renal function. Am J Med 1993; 95:161.

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.

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.

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).

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. 

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.

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. 

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.

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.

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.

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.

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.

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.

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.

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.

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. 

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.

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. 

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

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

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

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.

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.

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/

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

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.

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.

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

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.