pyogenic liver abscess

Q: Which of the following drugs has shown to cause pyogenic liver abscess?


A) beta-blockers
B) calcium channel blockers
C) proton-pump inhibitors
D) acetaminophen
E) thyroid replacement agents


Answer: C

Treatment with proton pump inhibitors has shown to be associated with increased mortality in patients with pyogenic liver abscess. Proton pump inhibitors increase the gastric pH resulting in impaired defense mechanisms against ingested pathogens. Klebsiella pneumoniae is reported to be the most notorious with overgrowth in the intestine and subsequent liver abscess.


References:

1. Lin HF, Liao KF, Chang CM, et al. Correlation between proton pump inhibitors and risk of pyogenic liver abscess. Eur J Clin Pharmacol 2017; 73:1019.

2. Wang YP, Liu CJ, Chen TJ, Lin YT, Fung CP. Proton pump inhibitor use significantly increases the risk of cryptogenic liver abscess: a population-based study. Aliment Pharmacol Ther. 2015 Jun;41(11):1175-81. doi: 10.1111/apt.13203. Epub 2015 Apr 13.

cephalosporins and renal insuff

Q: Which of the following cephalosporins does not need any dose adjustment in renal insufficiency/failure? 

A) Cefazolin
B) Cefotaxime
C) Ceftriaxone
D) Ceftazidime
E) Cefepime


Answer: C

The objective of above question is to highlight two important facts regarding ceftriaxone. This is the only cephalosporin which does not require renal adjustment. Its elimination half-life and plasma clearance does not correlate linearly with creatinine clearance. Also, ceftriaxone is the only drug which does note get removed via hemodialysis.

This is true till ceftriaxone dosage stays 2 grams or less per day.


#pharmacology



References: 

1.  Patel IH, Sugihara JG, Weinfeld RE, Wong EG, Siemsen AW, Berman SJ. Ceftriaxone pharmacokinetics in patients with various degrees of renal impairment. Antimicrob Agents Chemother. 1984;25(4):438–442. 

2. Livornese LL Jr, Slavin D, Gilbert B, Robbins P, Santoro J. Use of antibacterial agents in renal failure. Infect Dis Clin North Am 2004;18:556–67 

3. Aronoff GR. Drug Prescribing in Renal Failure: Dosing Guidelines for Adults. 4th ed. Philadelphia, Pa.: American College of Physicians, 1999.

Misplaced central line

Case report: "Emergency Physician intubated the patient and inserted a central line in the right subclavian vein....Pulmonologist ordered to continue IV fluids and maintain the patient’s central venous pressure (CVP) at 6 to 8 cm of water. At 10 a.m., a nurse contacted Pulmonologist and told him the patient’s CVP was in the 70s.....The radiologist read the chest films from July 24-28. On each of her reports, she recommended the subclavian line be repositioned as the tip of the catheter crossed the midline....When the patient’s sedation was lightened in anticipation of possible extubation, she was found to have weakness and decreased mobility on her left side.".

Read full case at https://hub.tmlt.org/case-studies/failure-to-report-misplaced-central-line

PDPH

Q: Who is at higher risk of Post Dural Puncture Headache (PDPH)? 

A) Males 
B) Females 


Answer: B

Lumbar puncture (LP) is a common procedure in ICU. There are many risk factors for PDPH. Female gender, pregnancy,  and young age are the major risk factors. This has been attributed to high levels of circulating estrogen.

#procedure




References:

1. Wu CL, Rowlingson AJ, Cohen SR, et al. Gender and post-dural puncture headache. Anesthesiology 2006; 105:613.

2. Khlebtovsky A, Weitzen S, Steiner I, et al. Risk factors for post lumbar puncture headache. Clin Neurol Neurosurg 2015; 131:78. 

3. Amorim JA, Gomes de Barros MV, Valença MM. Post-dural (post-lumbar) puncture headache: risk factors and clinical features. Cephalalgia 2012; 32:916. 

'maternal cause-specific' mortality in cardiac arrest

Q: Which of the following is found to be the leading 'maternal cause-specific' mortality in cardiac arrest in the United States?

A) Postpartum hemorrhage
B) Antepartum hemorrhage
C) Amniotic fluid embolism
D) Sepsis
E) Anesthesia complications


Answer: A

The Nationwide Inpatient Sample (NIS) over fifteen years from 1998 to 2011 from 4843 patients looked for 'maternal cause-specific' mortalities in cardiac arrest. Although there was a long list of causes but almost 28% of women die due to postpartum hemorrhage followed by about 17% due to antepartum hemorrhage. Other three leading causes were heart failure, amniotic fluid embolism, and sepsis.

Causes also include anesthesia complications, aspiration pneumonitis, venous thromboembolism, eclampsia, magnesium toxicity, status asthmaticus, aortic dissection, and others.

#ob-GYN


Reference: 

Mhyre JM, Tsen LC, Einav S, et al. Cardiac Arrest during Hospitalization for Delivery in the United States, 1998-2011. Anesthesiology 2014; 120:810

Diuresis in AKI

Q: Diuresis during resolution of acute kidney injury (AKI) is due to?

A) Glucosuria
B) Urea diuresis
C) Sodium diuresis
D) Water diuresis
E) Formation of new nephrons


Answer: B

Resolution of AKI causes diuresis due to urea as azotemia gets resolved. Urea is an osmotic agent. There are two other major causes of urea diuresis in ICU beside resolution of AKI. One is steroid therapy which causes tissue catabolism, and the second is the addition of high amounts of protein orally via a feeding tube or parenteral nutrition.

 Glucosuria also causes solute diuresis alike urea diuresis but it is in the setting of hyperglycemia (choice A).

 Sodium diuresis occurs during intravenous (IV) saline administration. A similar mechanism occurs when bilateral urinary tract obstruction is relieved. This should be distinguished from urea diuresis and is not exactly due to the resolution of AKI (choice C).

Water diuresis occurs during primary polydipsia, central Diabetes Insipidus, and nephrogenic Diabetic Insipidus (choice D).

Formation of new nephrons does not occur during resolution of AKI (choice E).

#nephrology


Reference: 

Forni LG, Darmon M, Ostermann M, et al. Renal recovery after acute kidney injury. Intensive Care Med. 2017;43(6):855–866. doi:10.1007/s00134-017-4809-x

coccidioidomycosis meningitis. in pregnancy

Q: 32 year old female with 12 weeks of pregnancy is admitted to ICU with coccidioidomycosis meningitis. CSF pressure reported normal on Lumbar Puncture (LP). What would be the first line of therapy? 

A) fluconazole 
B) Itraconazole 
C) Intrathecal amphotericin B 
D) echinocandins
E) Repeated LP


Answer: C

Azoles may have teratogenic effects on fetal bone formation. They are contraindicated in the first trimester of pregnancy. In such scenarios, intrathecal amphotericin B deoxycholate is the recommended therapy. Experts recommend avoiding azoles throughout the pregnancy.

Fluconazole and Itraconazole are azoles (choices A & B).

Interestingly, despite being very potent antifungals, echinocandins have no role in coccidioidal meningitis (choice D).


Repeated LPs are recommended for symptomatic relief only if CSF pressure is high (choice E).


#infectious-diseases
#ob-gyn
#neurology


References:

1. Bercovitch RS, Catanzaro A, Schwartz BS, et al. Coccidioidomycosis during pregnancy: a review and recommendations for management. Clin Infect Dis 2011; 53:363. 

2. Mølgaard-Nielsen D, Svanström H, Melbye M, et al. Association between use of oral fluconazole during pregnancy and risk of spontaneous abortion and stillbirth. JAMA 2016; 315:58.

3. Galgiani JN, Ampel NM, Blair JE, et al. 2016 Infectious Diseases Society of America (IDSA) Clinical Practice Guideline for the Treatment of Coccidioidomycosis. Clin Infect Dis 2016; 63:e112.

Korsakoff syndrome

Q: Korsakoff syndrome (KS) is characterized by? (select one)

A) selective anterograde amnesia
B) selective retrograde amnesia
C) both of the above
D) none of the above
E) generalized amnesia


Answer: C

Korsakoff syndrome (KS) is nothing but a distinct advanced neuropsychiatric manifestation of Wernicke encephalopathy (WE) with the same cause i.e., thiamine loss. This is more pronounced in ETOH abusers. It has its own specific MRI findings. It is a disorder of selective anterograde and retrograde amnesia. It is characteristically different from general amnesia (Choice E) as there is an intact sensorium, and preservation of long-term memory and other cognitive skills. Interestingly, attention and social behavior are usually preserved. Although confabulation is more common, patients with KS stay unaware of their illness. 

 KS is irreversible but Acetylcholinesterase inhibitors & memantine have been tried with some success.

#neurology


References:

1. Blansjaar BA, Van Dijk JG. Korsakoff minus Wernicke syndrome. Alcohol Alcohol 1992; 27:435.

2. Bowden SC. Separating cognitive impairment in neurologically asymptomatic alcoholism from Wernicke-Korsakoff syndrome: is the neuropsychological distinction justified? Psychol Bull 1990; 107:355. 

3. Cochrane M, Cochrane A, Jauhar P, Ashton E. Acetylcholinesterase inhibitors for the treatment of Wernicke-Korsakoff syndrome--three further cases show response to donepezil. Alcohol Alcohol 2005; 40:151. 

4.  Rustembegović A, Kundurović Z, Sapcanin A, Sofic E. A placebo-controlled study of memantine (Ebixa) in dementia of Wernicke-Korsakoff syndrome. Med Arh 2003; 57:149.

Rewarming

Q: Which of the following thermometers is most accurate during the rewarming phase in hypothermia?

A) rectal thermometers 
B) probe in lower one-third of the esophagus 
C) probe in upper one-third of the esophagus 
D) infrared tympanic thermometers 
E) bladder probes


Answer: B

Temperature probe inserted in the lower one-third of the esophagus - or to be precise - about 24 cm below the larynx) provides the best approximation of cardiac temperature. 

 Rectal temperature becomes unreliable during rewarming as it may be adjacent to cold feces, which may lag in rewarming (choice A).  Esophageal probes in the upper one-third area become unreliable due to heated humidified oxygen in endotracheal (ETT) (choice C). Similarly, infrared tympanic thermometers (temporal artery thermometers) are too superficial to be accurate (choice D). Bladder probe also lags behind during rewarming (choice E).

#hypothermia


References:

1. Danzl D. Accidental hypothermia. In: Wilderness Medicine, 6th ed, Auerbach PS (Ed), Elsevier, Philadelphia 2012. p.115.


2. Kempainen RR, Brunette DD. The evaluation and management of accidental hypothermia. Respir Care 2004; 49:192.

TLS

Q: All of the following electrolyte/lab abnormalities are part of Cairo-Bishop definition of laboratory tumor lysis syndrome except? 

A) Uric acid
B) Potassium 
C) Phosphorus
D) Calcium
E) Sodium


Answer: E 

Cairo-Bishop laboratory definition is the easiest way to establish the diagnosis of tumor lysis syndrome. If two or more laboratory values of uric acid, potassium, phosphorus, and calcium change > 25% at presentation or seven days after cytotoxic therapy.

#hematology


References: 

1. Cairo MS, Bishop M. Tumour lysis syndrome: new therapeutic strategies and classification. Br J Haematol 2004; 127:3. 

2. Coiffier B, Altman A, Pui CH, et al. Guidelines for the management of pediatric and adult tumor lysis syndrome: an evidence-based review. J Clin Oncol 2008; 26:2767

The risk of suicide

Q: 20 years old male with no previous history is admitted to ICU after a suicide attempt. Psychiatry service diagnosed him with schizophrenia. All of the following are risk factors for suicide except? 

A) Male 
B) High school drop-out
C) Active hallucinations 
D) Family history of suicide 
E) Substance Abuse 


Answer: B

The risk of suicide is high especially at the onset of schizophrenia. The risk goes further high in young and highly educated males with the presence of insight. Other risk factors include prior suicide attempts, depression, active hallucinations and delusions, family history of suicide and substance abuse.

#psychiatry


Reference:

Hor K, Taylor M. Suicide and schizophrenia: a systematic review of rates and risk factors. J Psychopharmacol 2010; 24:81.

Sexually Inappropriate Behavior in Dementia

Q: 72 year old male with senile dementia is admitted in ICU with community-acquired pneumonia. While recovering from pneumonia, he continues to display episodes of agitation and sexually inappropriate behavior. Which of the following gastro-intestinal (GI) drug is found to be effective in Sexually Inappropriate Behavior in Dementia?

A) Cimetidine 
B) Bismuth subsalicylate 
C) Omeprazole 
D) Metoclopramide


Answer: A

Cimetidine is an H2 receptor antagonist but also carries anti-androgen effects via blocking the androgen receptor in the pituitary or the hypothalamus. It reduces both arousal and orgasm.

#psychiatry
#neurology


References

1. Knigge U, Dejgaard A, Wollesen F, Ingerslev O, Bennett P, Christiansen PM. The acute and long term effect of the H2- receptor antagonist cimetidine and ranitidine on the pituitary gonadal axis in men. Clin Endocrinol (Oxf). 1983;18(3):307-313.

2. Anand Beri, Alan Smith. Cimetidine Treatment of Sexually Inappropriate Behavior in Dementia: A Case Report and Literature Review. Annals of Long-Term Care: Clinical Care and Aging. 2015;23(6):39-42.

DGS

Q: 24 year old female with DiGeorge syndrome (DGS) is admitted to ICU after her cardiac surgery for postop care. Which electrolyte abnormality should be carefully watched?

A) Hyperkaelemia
B) Hypokalemia
C) Hypernatremia
D) Hypocalcemia
E) Hypermagnesemia


Answer: D

DiGeorge syndrome (DGS) is caused by a heterozygous chromosomal deletion at 22q11.2. DiGeorge syndrome (DGS) is associated with defective development of the pharyngeal pouch system. It consists of a triad

• conotruncal cardiac anomalies,
• hypoplastic thymus (causing T cells deficit)
• parathyroid hypoplasia (causing hypocalcemia) 

Although the disease is mostly limited to children, a large number of adults reach adulthood and many get diagnosed as a parent of DGS! Adults have relatively lower cardiac anomalies but higher palatal and mental disabilities.

#electrolytes
#surgical-critical-care


References

1. Bassett AS, McDonald-McGinn DM, Devriendt K, et al. Practical guidelines for managing patients with 22q11.2 deletion syndrome. J Pediatr 2011; 159:332. 

2. Cohen E, Chow EW, Weksberg R, Bassett AS. Phenotype of adults with the 22q11 deletion syndrome: A review. Am J Med Genet 1999; 86:359.

DILI

Q; Which of the following drug causes Drug-Induced Liver Injury (DILI) by ischemic necrosis?

A) Ergot
B) Amiodarone
C) Lisinopril
D) Oral Contraceptives
E) Ethanol


Answer: A


The objective of the above question is to highlight that, it is not only necessary to know which drugs cause DILI but it is also important to know their mechanism of action (MOA). It helps in the differential diagnosis of DILI from other possible causes of liver injury in complex ICU patients.

 In the above question, Ergot is the only drug known to cause ischemic necrosis and pattern is usually more like 'shock liver'. In contrast, oral contraceptives (OCs) are the only group of drugs known to cause hepatic venous outflow obstruction, popularly known as Budd-Chiari syndrome (choice D), and can be confirmed by imaging. OCs may cause neoplasms too. Ethanol is known to cause DILI via various mechanisms including direct hepatocellular parenchymal damage, acute cholestasis, fibrosis, and microvesicular steatosis (choice E). Here AST is usually double of ALT. Lisinopril may cause acute parenchymal damage as well as chronic hepatitis, and often get ignored (choice C). Amiodarone injury mostly occurs via cholestasis, steatohepatitis, phospholipidosis, and microvesicular steatosis - and transaminases injury pattern would be different as it is less prone to cause direct hepatocellular injury (choice B).


#pharmacology
#hepatology


Reference:

Chang CY, Schiano TD. Review article: drug hepatotoxicity. Aliment Pharmacol Ther 2007; 25:1135.

Ramsay Hunt syndrome

Case: 47 year old immunocompromised m patient is in ICU with septic shock. The patient developed vesicles in the auditory canal. The infectious disease (ID) service wrote in the note: 'probable Ramsay Hunt syndrome' and added the treatment plan. What is Ramsay Hunt syndrome?

Answer:  Herpes Zoster Oticus, popularly known as Ramsay Hunt syndrome is a major otologic complication of Varicella-Zoster Virus reactivation. It may cause hearing loss. It is a triad of

• ipsilateral facial paralysis
• ear pain, and 
• vesicles in the auditory canal and auricle

Treatment is valacyclovir and prednisone.

#infectious-diseases


Reference:

Coulson S, Croxson GR, Adams R, Oey V. Prognostic factors in herpes zoster oticus (ramsay hunt syndrome). Otol Neurotol 2011; 32:1025.

Cocaine, VQ scan and PE

Q: What makes cocaine-induced pulmonary injury appears like pulmonary embolism (PE) on ventilation-perfusion (V/Q) lung scan?



Answer:  Cocaine causes a high degree of pulmonary arterial vasospasm. This results in V/Q scan to appear like PE. This can be highly deceiving and can lead to inappropriate anti-coagulation of patient.

#toxicology
#pulmonary


Reference:

Ramachandaran S, Khan AU, Dadaparvar S, Sherman MS. Inhalation of crack cocaine can mimic pulmonary embolism. Clin Nucl Med 2004; 29:756.

Suicide terms

Q; What is the difference between suicidal ideation, suicide threat, and suicide gesture?



Answer: Patients with any slightest clue of suicide are usually admitted to ICU for 24/7 monitoring till cleared by psychiatry service or transferred to the appropriate facility. Few terminologies are important to know as they may make a difference in clinical management. 

Suicidal ideation is the most worrisome phenomenon as a patient may not only have thoughts about killing himself but may have developed a plan to execute it. In contrast, patients with a suicide threat just intend others to believe that they want to die without any intention to die. Suicide gesture is a more organized form of threat where self-injurious behavior is displayed for others to believe that they want to die without any intention to die.

#psychiatry



References:

1. Nock MK. Self-injury. Annu Rev Clin Psychol 2010; 6:339.

2. McCullumsmith C. Laying the groundwork for standardized assessment of suicidal behavior. J Clin Psychiatry 2015; 76:e1333.

AT-3

Q: Hemodialysis? (select one)

A) Increases the level of Antithrombin iii (AT-3)
B) Reduces the level of Antithrombin iii (AT-3)


Answer: B

AT-3 deficiency can be either hereditary or acquired. There are many clinical situations which reduce the level of AT-3 and consequently make it hard for effective anticoagulation with heparin. Some of such important clinical scenarios are:

• Disseminated intravascular coagulation (DIC) 
• Acute thrombosis 
• Cirrhosis 
• Nephrotic syndromes 
• Extracorporeal membrane oxygenation (ECMO) 
• Hemodialysis 
• Trauma 
• Preeclampsia and eclampsia

#hematology

References:

1. Mammen EF. Antithrombin: its physiological importance and role in DIC. Semin Thromb Hemost 1998; 24:19. 

2. Raya-Sánchez JM, González-Reimers E, Rodríguez-Martín JM, et al. Coagulation inhibitors in alcoholic liver cirrhosis. Alcohol 1998; 15:19. 

3. Kauffmann RH, Veltkamp JJ, Van Tilburg NH, Van Es LA. Acquired antithrombin III deficiency and thrombosis in the nephrotic syndrome. Am J Med 1978; 65:607. 

4. Alegre A, Vicente V, Gonzalez R, Alberca I. Effect of hemodialysis on protein C levels. Nephron 1987; 46:386. 

5. Weenink GH, Treffers PE, Vijn P, et al. Antithrombin III levels in preeclampsia correlate with maternal and fetal morbidity. Am J Obstet Gynecol 1984; 148:1092.

IV adenosine

Q; IV push of 6-12 mg of Adenosine should ideally be given via? (select one)

A) peripheral line
B) central line


Answer: A

The recommended IV dose of 6 or 12 mg of Adenosine is recommended for rapid push via peripheral IVs. Dose should be drastically cut down to 3 or even 1 mg if central venous, particularly upper body access is used.

#cardiology



References: 

Ferguson JD, DiMarco JP. Contemporary management of paroxysmal supraventricular tachycardia. Circulation 2003; 107:1096. 

 Link MS. Clinical practice. Evaluation and initial treatment of supraventricular tachycardia. N Engl J Med 2012; 367:1438.

hydralazine-asso.-lupus

Q: 32 year old female is admitted to ICU with lupus associated pulmonary embolism. Rheumatology service diagnosed her lupus secondary to her prescription of hydralazine. Various 'panels' of lab tests have been send. In Hydralazine-associated-lupus, Anti-double stranded (ds) DNA antibodies is supposed to be? (select one)

A) Negative
B) Positive


Answer: A

Although Anti-ds-DNA are usually positive in drug-induced disease with other agents, they are typically absent in drug-induced lupus due to procainamide, hydralazine, and isoniazid.

#rheumatology



Reference:

Iyer P, Dirweesh A, Zijoo R. Hydralazine Induced Lupus Syndrome Presenting with Recurrent Pericardial Effusion and a Negative Antinuclear Antibody. Case Rep Rheumatol. 2017;2017:5245904. doi:10.1155/2017/5245904

HeRO graft

Q: What is HeRO graft?

Answer: HeRO graft stands for Hemodialysis Reliable Outflow (HeRO) graft. HeRO graft is the last salvage access for patients who have exhausted all other conventional upper extremities Arterio-Venous (AV) fistula graft sites. The objective is to preserve the thigh access sites for future use. HeRO graft provides outflow for patients with central venous stenosis or occlusion. At one end it is anastomosed proximally to the brachial artery or another inflow artery, and another end to central venous circulation through the internal jugular vein, subclavian vein, or other veins that provides access into the central circulation with the distal tip of the catheter is positioned in the right atrium. 

#procedures


Reference:

Al Shakarchi J, Houston JG, Jones RG, Inston N. A Review on the Hemodialysis Reliable Outflow (HeRO) Graft for Haemodialysis Vascular Access. Eur J Vasc Endovasc Surg 2015; 50:108.

Femoral line

Q: For femoral central line, it helps to? (select one)

A) abduct the leg
B) adduct the leg


Answer; A

Positioning to place any CVC plays an important role in its success. For femoral central line, few tricks may help. Ideally, the patient should be placed supine. Abducting the target leg and rotating externally 15 degrees open the femoral triangle. Also, elevating the buttock with rolled bed-sheets or pillows helps in better exposure to femoral vessels.

#procedures


Reference:

1. Kim W, Chung RK, Lee GY, Han JI. The effects of hip abduction with external rotation and reverse Trendelenburg position on the size of the femoral vein; ultrasonographic investigation. Korean J Anesthesiol. 2011;61(3):205–209. doi:10.4097/kjae.2011.61.3.205

2. Bannon MP, Heller SF, Rivera M. Anatomic considerations for central venous cannulation. Risk Manag Healthc Policy 2011; 4:27.

hypothermia

Q: Effect of hypothermia on platelet dysfunction starts at what temperature?

A) 36°C
B) 34°C 
C) 32°C 
D) 30°C 


Answer: B

Hypothermia induces thrombocytopathy via two mechanisms. Primarily, hypothermia reduces the enzymatic activity of plasma coagulation proteins. Secondarily, by preventing the activation of platelets via traction on the glycoprotein Ib/IX/V complex by von Willebrand factor. The onset of this effect is seen as core temperatures drops to 34°C.

#hematology


Reference:

Kermode JC, Zheng Q, Milner EP. Marked temperature dependence of the platelet calcium signal induced by human von Willebrand factor. Blood 1999; 94:199. 

Jurkovich GJ, Greiser WB, Luterman A, Curreri PW. Hypothermia in trauma victims: an ominous predictor of survival. J Trauma 1987; 27:1019.

BC via CVC

Q: Drawing blood cultures from 'just inserted' central venous catheter (CVC)? (select one) 

A) decreases the likelihood of false-positive blood culture 
B) increases the likelihood of false-positive blood culture


Answer: B

Unfortunately, the 'bad' practice of drawing blood cultures from the just inserted CVC is on the rise under the perception that the site is clean and will not affect the result of blood culture. On the contrary, it falsely increases the chances of positive blood culture. If it's not possible to obtain both cultures 'peripherally', an attempt should be made at least to get one culture peripherally - and labeled properly before sending to the laboratory.

#infectious-diseases


Reference:

Boyce JM, Nadeau J, Dumigan D, et al. Obtaining blood cultures by venipuncture versus from central lines: impact on blood culture contamination rates and potential effect on central line-associated bloodstream infection reporting. Infect Control Hosp Epidemiol 2013; 34:1042.

BMV

Q: During bag-mask ventilation (BMV), what is the best way to reduce the likelihood of decreasing gastric inflation? 


 Answer: Squeezing the bag slowly over one full second reduces the likelihood of decreasing gastric inflation. A slowly delivered tidal volume prevents sufficient pressure to open the gastroesophageal sphincter.

It also helps to prevent a dramatic impact on the cardiac output of a patient.

#procedure


Reference: 

Fitz-Clarke JR. Fast or Slow Rescue Ventilations: A Predictive Model of Gastric Inflation. Fitz-Clarke JR1. Respir Care. 2018 May;63(5):502-509. doi: 10.4187/respcare.05620.

LRINEC

Q: Which of the following is not part of Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score?

A) C-reactive protein 
B) White blood cell  
C) Hemoglobin  
D) Potassium 
E) Creatinine


Answer: D

NF at the base is a clinical diagnosis. If suspicion for necrotizing fasciitis is high on clinical grounds, the patient should proceed straight to the OR. LRINEC should be calculated in equivocal cases. All of the above are the part of score except potassium. Instead, sodium is included in the score. 135 meq/L is the cutoff point for sodium in LRINEC score. 

LRINEC calculators are available at various web search engines (Ref#2) and very easy to calculate with only five components. A score of 8 has a PPV of 93.4% for NF.

#musculo-skeletal 


References:

1. Wong CH, Khin LW, Heng KS, et al. The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis) score: a tool for distinguishing necrotizing fasciitis from other soft tissue infections. Crit Care Med 2004; 32:1535.


2. https://www.mdcalc.com/lrinec-score-necrotizing-soft-tissue-infection#next-steps

ICA and VA dissections

Q: Transient monocular blindness is more common with? (select one) 

A) Internal carotid artery dissection 
B) Vertebral artery dissection 


 Answer: A

 Transient monocular blindness exclusively occurs in internal carotid artery dissection (ICA-D).

Although cerebral and cervical arterial dissections can occur at any age, they are a common cause of stroke in the young, and the most highly associated factor is the strenuous physical activity. Clinically, spontaneous cerebral and cervical artery dissection can be differentiated before imagings can be pursued. Internal carotid artery dissection (ICA-D) is relatively more common in men. The history of infection in the previous week is more common with ICA-D, and the history of cervical trauma in the previous week is more common with vertebral artery dissection (VA-D). Similarly, neck pain is more associated with VA-D. 


#neurology


Reference:

Debette S, Grond-Ginsbach C, Bodenant M, et al. Differential features of carotid and vertebral artery dissections: the CADISP study. Neurology 2011; 77:1174.

Toxicology

Q: 52 year old mining worker is admitted to ICU with episodes of torsades de pointes after an exposure to large amount of fumes. Patient c/o abdominal cramps, watery diarrhea and a garlic odor of the breath and stool. Toxicity of which element should be suspected? 


Answer: Arsenic

Acute arsenic poisoning has some distinct characteristics like abdominal symptoms but with severe watery diarrhea, a garlic odor of the breath and stool, QTc prolongation with or without torsades de pointes, acute respiratory distress syndrome, acute encephalopathy with or without seizures, proteinuria, hematuria, and acute tubular necrosis. This list continues and involves almost every body system.

#toxicology


References:

1. Mundy SW. Arsenic. In: Goldfrank's Toxicologic Emergencies, 10th ed, Hoffman RS, Lewin NA, Howland MA, et al (Eds), Mcgraw-Hill Education, New York 2015. p.1169. 

2.  Agency for Toxic Substances and Disease Registry. Toxicological Profile for Arsenic. U.S. Department of Health & Human Services, Public Health Service 2007. Available at: www.atsdr.cdc.gov/toxprofiles/tp.asp?id=22&tid=3 (Accessed on July 25, 2019).

3. Chhuttani P, Chopra J. Arsenic Poisoning. In: Handbook of Clinical Neurology: Intoxication of the Nervous System, part I, Vinken P, Bruyn G (Eds), North Holland, Amsterdam 1979. Vol 36, p.199.

Permissive hypoxemia

Q: The formula for 'Inspiratory Time' (IT) on the ventilator is the tidal volume divided by? (select one)

A) the inspiratory flow rate
B) the respiratory rate


Answer: A

Inspiratory time is the tidal volume divided by the inspiratory flow rate.

Clinical implication: Increasing IT increases the I; E ratio on the ventilator and induce the lung injury. Many times in the quest to achieve higher oxygenation,  clinicians increase the IT but the overall impact may be deleterious with an alveolar injury. Concept of "permissive hypoxemia" should be entertained in severe situations till hemodynamics are stable and organ functions are not jeopardized.

#ventilators


References:

1. He HW, Liu DW. Permissive hypoxemia/conservative oxygenation strategy: Dr. Jekyll or Mr. Hyde?. J Thorac Dis. 2016;8(5):748–750.

2. Casetti AV, Bartlett RH, Hirschl RB. Increasing inspiratory time exacerbates ventilator-induced lung injury during high-pressure/high-volume mechanical ventilation. Crit Care Med. 2002;30:2295–9.

MINS

Q: Pulmonary embolism (PE), sepsis, or cardioversion are considered the main reasons behind myocardial injury after noncardiac surgery (MINS)? (select one)

A) True
B) False


Answer: B

The main reason behind MINS is usually either underlying coronary artery disease CAD) or an acute thrombus. Perioperative MI due to PE, sepsis or cardioversion during surgery are not even considered as a cause in MINS. The most important thing to remember is that any troponin elevation in non-cardiac surgery implies myocardial injury or ischemia, and underlying CAD should be strongly considered and pursued.

#cardiology


References:

1. Botto F, Alonso-Coello P, Chan MT, et al. Myocardial injury after noncardiac surgery: a large, international, prospective cohort study establishing diagnostic criteria, characteristics, predictors, and 30-day outcomes. Anesthesiology 2014; 120:564. 

2. Gualandro DM, Campos CA, Calderaro D, et al. Coronary plaque rupture in patients with myocardial infarction after noncardiac surgery: frequent and dangerous. Atherosclerosis 2012; 222:191. 

3. Sheth T, Natarajan MK, Hsieh V, et al. Incidence of thrombosis in perioperative and non-operative myocardial infarction. Br J Anaesth 2018; 120:725. 

4.  Landesberg G, Beattie WS, Mosseri M, et al. Perioperative myocardial infarction. Circulation 2009; 119:2936. 

5. Writing Committee for the VISION Study Investigators, Devereaux PJ, Biccard BM, et al. Association of Postoperative High-Sensitivity Troponin Levels With Myocardial Injury and 30-Day Mortality Among Patients Undergoing Noncardiac Surgery. JAMA 2017; 317:1642. 

6. Puelacher C, Lurati Buse G, Seeberger D, et al. Perioperative Myocardial Injury After Noncardiac Surgery: Incidence, Mortality, and Characterization. Circulation 2018; 137:1221.