Sunday, January 17, 2021

detection of tracheal aspiration

 Q: Which of the following is more reliable in detecting tracheal aspiration of gastro-intestinal (GI) contents? (select one)

A) Methylene blue test 

B) Glucose oxidase test


Answer: B

The two most common methods used to detect aspiration in patients especially in post-trach tubes patients beside direct visualization and bronchoscopy are methylene blue test and glucose oxidase test. 

In Methylene blue test, a dye is added to the enteral feedings and then looking for it in tracheal secretions. Unfortunately, this has a very high false negative rate. 

In glucose oxidase testing, the glucose test strips and a glucose meter is used to measure the glucose level in the tracheal secretions. The high glucose level in the tracheal secretions is considered highly suggestive of tracheal aspiration.

#pulmonary


References:

1. Belafsky PC, Blumenfeld L, LePage A, Nahrstedt K. The accuracy of the modified Evan's blue dye test in predicting aspiration. Laryngoscope 2003; 113:1969. 

2. Fiorelli A, Ferraro F, Nagar F, et al. A New Modified Evans Blue Dye Test as Screening Test for Aspiration in Tracheostomized Patients. J Cardiothorac Vasc Anesth 2017; 31:441. 

3.  Potts RG, Zaroukian MH, Guerrero PA, Baker CD. Comparison of blue dye visualization and glucose oxidase test strip methods for detecting pulmonary aspiration of enteral feedings in intubated adults. Chest 1993; 103:117.

Saturday, January 16, 2021

confirming ETT

 Q: Chest radiography (CXR) is the ideal way to rule out esophageal misplacement after tracheal intubation? 

A) True 

B) False 


 Answer:

 A single view CXR is more helpful to estimate the depth of the endo-tracheal-tube (ETT) but it is not the best way to exclude esophageal intubation. End-tidal carbon dioxide (ETCO2) is relatively a more reliable method to confirm ETT placement in the trachea in the non-cardiac arrest patient. Clinician should be aware that the esophagus also yields some detectable quantity of CO2 during the first few breaths. Five to six exhalations with a consistent CO2 exhalation is a reliable indicator of tracheal placement of ETT. 

This can be supplemented by other supportive (but not confirmatory) evidences such as '5-points' auscultation of breath and epigastric sounds, rise of the chest wall, condensation of the ETT, use of esophageal detector device (EDD), gently repassing the introducer through the ETT to feel the tracheal rings or carina, use of ultrasound and CXR.

Bronchoscope continue to be the gold standard to confirm ETT placement in cardiac and non-cardiac arrest patients

#procedures


References:

1. Grmec S. Comparison of three different methods to confirm tracheal tube placement in emergency intubation. Intensive Care Med 2002; 28:701.

2.  Jenkins WA, Verdile VP, Paris PM. The syringe aspiration technique to verify endotracheal tube position. Am J Emerg Med 1994; 12:413. 

3. Bair AE, Laurin EG, Schmitt BJ. An assessment of a tracheal tube introducer as an endotracheal tube placement confirmation device. Am J Emerg Med 2005; 23:754. 

4. Smith GM, Reed JC, Choplin RH. Radiographic detection of esophageal malpositioning of endotracheal tubes. AJR Am J Roentgenol 1990; 154:23. 

5. Chou HC, Tseng WP, Wang CH, et al. Tracheal rapid ultrasound exam (T.R.U.E.) for confirming endotracheal tube placement during emergency intubation. Resuscitation 2011; 82:1279.


Friday, January 15, 2021

PPH

 Q: 32 years old female is admitted to ICU from Labor and Delivery (L & D). Which of the following is a higher risk factor for postpartum hemorrhage (PPH)? (select one)

 A) Retained placenta/membranes 

 B) Eclampsia 


 Answer: A

In terms of Odd Ratio (OR) retained placenta/membranes is the highest risk factors for PPH. 

Evaluating 666 PPH from 154,000 deliveries retained placenta/membranes has an OR of 3.5 whereas preeclampsia/eclampsia/HELLP syndrome has an OR of 1.7 for PPH. Other high risk factors were failure to progress during the second stage of labor (OR 3.4), morbidly adherent placenta (OR 3.3), lacerations (OR 2.4), instrumental delivery (OR 2.3), large for gestational age newborn (OR 1.9), induction of labor (OR 1.4), and prolonged first or second stage of labor (OR 1.4). 1 

There are many other risk factors for PPH which includes placenta accreta or previa, placental abruption, intrauterine fetal demise, previous history, family history, obesity, high parity, Asian or Hispanic race, multiple gestation, polyhydramnios, macrosomia, chorioamnionitis, uterine inversion, leiomyoma, Couvelaire uterus, inherited bleeding diathesis, uterine relaxants, and use of SSRIs by a patient.


#ob-Gyn


References:

1. Sheiner E, Sarid L, Levy A, et al. Obstetric risk factors and outcome of pregnancies complicated with early postpartum hemorrhage: a population-based study. J Matern Fetal Neonatal Med 2005; 18:149. 

2. Bateman BT, Berman MF, Riley LE, Leffert LR. The epidemiology of postpartum hemorrhage in a large, nationwide sample of deliveries. Anesth Analg 2010; 110:1368. 

3. Kramer MS, Berg C, Abenhaim H, et al. Incidence, risk factors, and temporal trends in severe postpartum hemorrhage. Am J Obstet Gynecol 2013; 209:449.e1. 

4. Sharp GC, Saunders PT, Greene SA, et al. Intergenerational transmission of postpartum hemorrhage risk: analysis of 2 Scottish birth cohorts. Am J Obstet Gynecol 2014; 211:51.e1. 

5. Bruning AH, Heller HM, Kieviet N, et al. Antidepressants during pregnancy and postpartum hemorrhage: a systematic review. Eur J Obstet Gynecol Reprod Biol 2015; 189:38. 

6. Skalkidou A, Sundström-Poromaa I, Wikman A, et al. SSRI use during pregnancy and risk for postpartum haemorrhage: a national register-based cohort study in Sweden. BJOG 2020; 127:1366.

Thursday, January 14, 2021

gallstone related acute cholecystitis in pregnancy

 Q: 24 years old female in 22 weeks of pregnancy is admitted to ICU with concern for sepsis secondary to gallstone related acute cholecystitis. Which of the following antibiotics should be avoided? (select one)

A) Metronidazole 

B) Aztreonam 

C) Ceftriaxone 

D) Clindamycin 

E) Meropenem 


Answer:  (Meropenem)

Management of gallstone-related complications is usually supportive in pregnancy and not much different than the general population including surgery if required. Like all other antibiotics, two classes of antibiotics should be avoided in pregnancy i.e., fluoroquinolones and carbapenems due to the risk of fetal toxicity. 

Monotherapy is usually enough with ampicillin-sulbactam, piperacillin-tazobactam, or ticarcillin-clavulanate. Another acceptable regimen is a combination of third-generation cephalosporin (ceftriaxone) and metronidazole. Clindamycin can be used in penicillin allergy. Aztreonam is also described as safe in pregnancy.


#ID

#Ob-Gyn

#hepatology


References:

1. Chloptsios C, Karanasiou V, Ilias G, Kavouras N, Stamatiou K, Lebren F. Cholecystitis during pregnancy. A case report and brief review of the literature. Clin Exp Obstet Gynecol. 2007;34(4):250-1. PMID: 18225691. 

2. Tseng JY, Yang MJ, Yang CC, Chao KC, Li HY. Acute Cholecystitis During Pregnancy: What is the Best Approach? Taiwan J Obstet Gynecol. 2009 Sep;48(3):305-7. doi: 10.1016/S1028-4559(09)60311-9. PMID: 19797027. 

3. İlhan M, İlhan G, Gök AFK, Günay K, Ertekin C. The course and outcomes of complicated gallstone disease in pregnancy: Experience of a tertiary center. Turk J Obstet Gynecol. 2016;13(4):178-182. doi:10.4274/tjod.65475

4. Bookstaver PB, Bland CM, Griffin B, Stover KR, Eiland LS, McLaughlin M. A Review of Antibiotic Use in Pregnancy. Pharmacotherapy. 2015 Nov;35(11):1052-62. doi: 10.1002/phar.1649. PMID: 26598097.

Wednesday, January 13, 2021

ketamine as IM

 Q: Ketamine can be given as an intramuscular (IM) injection to an acutely agitated patient? 

A) Yes

B) No


Answer: A

Ketamine can be given as an IM injection to an acutely agitated patient. It has a relatively same safety profile and works quicker than a benzodiazepine (BZD) or haloperidol. IM dose is double than IV dose i.e., 4 to 6 mg/kg. The onset of action is approximately within 5 minutes and the duration of action is about 10-20 minutes. It can be a good bridging modality for a more stable and longer treatment plan. The dose can be repeated at half of the initial dose if needed. Similarly, the dose should be reduced if a patient has received or receiving any other antipsychotic medication(s). 

 In ICU, an IV route can be utilized with a 1 to 2 mg/kg dose.

Said that clinician should be prepared for side-effects such as an increase in blood pressure and heart rate as well as nausea and vomiting. Laryngospasm is unlikely but can occur. Ketamine is contraindicated in patients with hallucinations and schizophrenia. It is preferred to avoid in very elderly and cardiac patients.

#pharmacology

#delirium

#neurology

#agitation


References:

1. Ho JD, Smith SW, Nystrom PC, et al. Successful management of excited delirium syndrome with prehospital ketamine: two case examples. Prehosp Emerg Care 2013; 17:274. 

2.  Isbister GK, Calver LA, Downes MA, Page CB. Ketamine as Rescue Treatment for Difficult-to-Sedate Severe Acute Behavioral Disturbance in the Emergency Department. Ann Emerg Med 2016; 67:581. 

3. Riddell J, Tran A, Bengiamin R, et al. Ketamine as a first-line treatment for severely agitated emergency department patients. Am J Emerg Med 2017; 35:1000. 

4. Mankowitz SL, Regenberg P, Kaldan J, Cole JB. Ketamine for Rapid Sedation of Agitated Patients in the Prehospital and Emergency Department Settings: A Systematic Review and Proportional Meta-Analysis. J Emerg Med 2018; 55:670. 

5.  O'Connor L, Rebesco M, Robinson C, et al. Outcomes of Prehospital Chemical Sedation With Ketamine Versus Haloperidol and Benzodiazepine or Physical Restraint Only. Prehosp Emerg Care 2019; 23:201.

Tuesday, January 12, 2021

Drug Induced NCSE

 Q: Which antibiotic is most notorious to cause Non-Convulsive Status Epilepticus (NCSE)? 

Answer: Cefepime 

 Drug-induced NCSE is frequently missed in ICU. Beta-lactam antibiotics are well known to cause NCSE particularly in the presence of kidney dysfunction. The most notorious antibiotic known in this regard is cefepime. Other drugs to cause NSCE are quinolones, ifosfamide, L-asparaginase, cisplatin, and busulfan. Immunosuppressant drugs such as cyclosporine and tacrolimus cause NSCE indirectly by causing posterior reversible encephalopathy syndrome (PRES).

#neurology

#pharmacology


References:

1. Fugate JE, Kalimullah EA, Hocker SE, et al. Cefepime neurotoxicity in the intensive care unit: a cause of severe, underappreciated encephalopathy. Crit Care 2013; 17:R264. 

2. Anzellotti F, Ricciardi L, Monaco D, et al. Cefixime-induced nonconvulsive status epilepticus. Neurol Sci 2012; 33:325. 

3. Thabet F, Al Maghrabi M, Al Barraq A, Tabarki B. Cefepime-induced nonconvulsive status epilepticus: case report and review. Neurocrit Care 2009; 10:347. 

4. Naeije G, Lorent S, Vincent JL, Legros B. Continuous epileptiform discharges in patients treated with cefepime or meropenem. Arch Neurol 2011; 68:1303. 

5.  Kozak OS, Wijdicks EF, Manno EM, et al. Status epilepticus as initial manifestation of posterior reversible encephalopathy syndrome. Neurology 2007; 69:894.

Monday, January 11, 2021

PTX and lateral decub x-ray

 Q: What is the advantage of Chest x-ray (CXR) in lateral decubitus position to confirm pneumothorax (PTX)? 

 Answer: In comparison to regular one-view CXR either in supine, sitting, or standing position, lateral decubitus position is more sensitive in detecting PTX. As little as 5 mL of pleural air is enough to show PTX in this position as air rises to the non-dependent lateral area. In other positions, it may require up to 50 mL of air to show evidence of PTX. 

Said that, with new modalities like ultrasound available, and laborious task it can be as well as counting safety of the patient, x-ray in lateral decubitus position is seldom obtained in ICU.

#procedure

#radiology

#pulmonary


References:

1. Carr JJ, Reed JC, Choplin RH, et al. Plain and computed radiography for detecting experimentally induced pneumothorax in cadavers: implications for detection in patients. Radiology 1992; 183:193. 

2. de Lassence A, Timsit JF, Tafflet M, Azoulay E, Jamali S, Vincent F, et al. Pneumothorax in the intensive care unit: incidence, risk factors, and outcome. Anesthesiology. 2006 Jan. 104 (1):5-13. 

3. Ball CG, Kirkpatrick AW, Feliciano DV. The occult pneumothorax: what have we learned?. Can J Surg. 2009 Oct. 52 (5):E173-9. 

4. Thiam K, Guinde J, Laroumagne S, et al. Lateral decubitus chest radiography or chest ultrasound to predict pleural adhesions before medical thoracoscopy: a prospective study. J Thorac Dis. 2019;11(10):4292-4297. doi:10.21037/jtd.2019.09.54

Sunday, January 10, 2021

SDH after LP

Case: 34 years old male is admitted to ICU with symptoms of possible meningitis. The resident on call decided to perform Lumbar Puncture (LP). Post-procedure, patient complains of severe headache. CT head showed subdural hematoma (SDH). What is the mechanism of Subdural hematoma after LP? 


Answer: 

Any iatrogenic cause of cerebrospinal fluid leak leads to low cerebrospinal fluid pressure. This intracranial hypotension decreases the buoyancy of the brain. Decrease buoyancy causes traction on the anchoring and supporting structures including bridging veins. It leads to the tearing of these vessels. Moreover, intracranial hypotension directly causes the cerebral veins engorgement and leakage of fluid into the subdural space.

#neurology

#neurosurgery

#procedures


References:

1. Abdullah M, Elkady A, Bushnag A, Seddeq Y, Alkutbi A. Acute Subdural Haemorrhage as a Complication of Diagnostic Lumbar Puncture. Cureus. 2020;12(4):e7515. Published 2020 Apr 2. doi:10.7759/cureus.7515

2. Kim HJ, Cho YJ, Cho JY, Lee DH, Hong KS. Acute subdural hematoma following spinal cerebrospinal fluid drainage in a patient with freezing of gait. J Clin Neurol. 2009;5(2):95-96. doi:10.3988/jcn.2009.5.2.95

Saturday, January 9, 2021

Pulmonary edema in ASA overdose

Q: The best approach to treat pulmonary edema induced due to salicylate toxicity is? (select one) 

A) aggressive volume resuscitation 
B) sodium bicarbonate 
C) emergent hemodialysis 
D) acidification of urine
E) activated charcoal


Answer: C

Non-cardiogenic pulmonary edema in salicylate toxicity requires emergent hemodialysis. In fact, this is considered an absolute indication of emergent hemodialysis. All other options tend to worsen the pulmonary edema including intravenous fluid resuscitation (choice A) and sodium bicarbonate (choice B). Salicylate poisoning requires alkalinization of urine, not acidification (choice D). Activated charcoal is helpful in the initial stages of poisoning for gastric decontamination but plays no role in relieving pulmonary edema (choice E).

#toxicology


References:

1. Heffner JE, Sahn SA. Salicylate-induced pulmonary edema. Clinical features and prognosis. Ann Intern Med 1981; 95:405. 

2. Glisson JK, Vesa TS, Bowling MR. Current management of salicylate-induced pulmonary edema. South Med J 2011; 104:225. 

3. Papacostas MF, Hoge M, Baum M, Davila SZ. Use of continuous renal replacement therapy in salicylate toxicity: A case report and review of the literature. Heart Lung 2016; 45:460.

Friday, January 8, 2021

CRRT flow

 Q: Which of the following may cause the clotting of the filter in Continous Renal Replacement Therapy (CRRT)? (select one)

A) High flow across the circuit

B) Low flow across the circuit

C) Both high and low flow across the circuit


Answer: C

Many patients may not be candidates for anticoagulation during CRRT and varied pressure due to varied flow across the CRRT circuit may render this intervention futile. 

The optimum blood flow across the CRRT circuit is considered to be around 200 mL/min. Low blood flow causes stasis of the blood and leads to filter clotting. On the other hand, high blood flow may trigger pressure alarms and stop the blood flow as a safety measure installed in the CRRT machine. Extracorporeal circuit tubing and hemofilter can process a limited volume of blood before its degradation. High blood flow accelerates this process. 

#nephrology


References:

1. Baldwin I, Bellomo R, Koch B. Blood flow reductions during continuous renal replacement therapy and circuit life. Intensive Care Med 2004; 30:2074.

2. Fealy N, Aitken L, du Toit E, et al. Faster Blood Flow Rate Does Not Improve Circuit Life in Continuous Renal Replacement Therapy: A Randomized Controlled Trial. Crit Care Med 2017; 45:e1018.

Thursday, January 7, 2021

PTX - most common cause

 Q: The most common cause of iatrogenic pneumothorax is? (select one) 

 A) central venous catheterization (central line) 

 B) thoracentesis

C) barotrauma (mechanical ventilation) 

 D) exercise 


Answer: A

The objective of the question is to highlight the fact that thoracentesis is relatively a safer procedure in contrast to central lines. This becomes even safer in an experienced hand and under ultrasound guidance. Actually, the risk of pneumothorax is found to be more than double for central lines than for thoracentesis (44% vs 20%).  Added risk factors for pneumothoraces are emergently performed procedures and teaching hospitals. Barotrauma (choice C) and exercise (choice D) are relatively less frequent in comparison to other choices in the question.

#procedures


References:

1. Celik B, Sahin E, Nadir A, Kaptanoglu M. Iatrogenic pneumothorax: etiology, incidence and risk factors. Thorac Cardiovasc Surg 2009; 57:286. 

2. Smit JM, Raadsen R, Blans MJ, et al. Bedside ultrasound to detect central venous catheter misplacement and associated iatrogenic complications: a systematic review and meta-analysis. Crit Care 2018; 22:65. 

3. John J, Seifi A. Incidence of iatrogenic pneumothorax in the United States in teaching vs. non-teaching hospitals from 2000 to 2012. J Crit Care 2016; 34:66.

Wednesday, January 6, 2021

left apical cap

 Q: "Left apical cap" sign in blunt thoracic trauma is suggestive of damage to which organ?

A) lung

B) pericardium

C) thyroid

D) aorta

E) clavicle


Answer: D

A chest x-ray is usually the first imaging available to clinicians after trauma presentation. Although signs on CXR are not conclusive but can be suggestive of underlying organ damage. Blunt aortic injury (BAI) can be presumed from CXR. Few suggestive signs of BAI are 

  •  Wide mediastinum 
  •  Obscured aortic knob 
  • Left "apical cap" sign i.e., (ie, pleural blood above the apex of left lung) 
  • Left hemothorax 
  • Nasogastric tube deviated towards the right 
  • Trachea deviated towards the right 
  • Right mainstem bronchus deviates downward

'Left apical sign' can be seen in other non-traumatic situations too like old age, pleural scarring, radiation fibrosis, Pancoast tumor, lymphoma, and abscess.


#trauma


References:

1. Kirwadi A, Pakala VB, Kumar DS, et al Apical left extrapleural cap: an early and important sign on chest radiographs. Emergency Medicine Journal 2008;25:819.. 

2. Kram HB, Appel PL, Wohlmuth DA, Shoemaker WC. Diagnosis of traumatic thoracic aortic rupture: a 10-year retrospective analysis. Ann Thorac Surg 1989; 47:282. 

3. Ekeh AP, Peterson W, Woods RJ, et al. Is chest x-ray an adequate screening tool for the diagnosis of blunt thoracic aortic injury? J Trauma 2008; 65:1088.

Tuesday, January 5, 2021

Ototoxicity from lasix

 Q: The risk of ototoxicity from furosemide can be minimized by giving it as a continuous infusion instead of intravenous boluses?

A) True

B) False


Answer: A

 Loop diuretics inhibit the transport in the loop of Henle that is mediated by a Na-K-2Cl cotransporter. An isoform of this cotransporter is present in the inner ear resulting in decreased endolymph secretion and so damage to the inner ear. This manifests as deafness, tinnitus and imbalance. 

Studies have shown that this effect gets highly enhanced with IV boluses of furosemide. Continuous intravenous infusion curtails the risk of ototoxicity remarkably.

#pharmacology


References:

1. Gallagher KL, Jones JK. Furosemide-induced ototoxicity. Ann Intern Med 1979; 91:744. 

2.  Dormans TP, van Meyel JJ, Gerlag PG, et al. Diuretic efficacy of high dose furosemide in severe heart failure: bolus injection versus continuous infusion. J Am Coll Cardiol 1996; 28:376. 

3. Salvador DR, Rey NR, Ramos GC, Punzalan FE. Continuous infusion versus bolus injection of loop diuretics in congestive heart failure. Cochrane Database Syst Rev 2005; :CD003178.

Monday, January 4, 2021

BZD reversal

 Q: What is the maximum dose of Flumazenil which can be administrated in an hour? (select one)

A) 1 mg

B) 3 mg

C) 5 mg


Answer: B

Flumazenil is frequently used in ICU to reverse the effect of benzodiazepine (BZD). The major hurdle in it's success is its shorter half life in comparison to BZD, and repeated doses may be required. One of the risk factor with higher dose of Flumazenil is seizures. Ideally, no more than 1 mg should be used but in extreme situation no more than 3 mg should be given within an hour. It is usually administrated in divided doses of 0.2 mg each time and each dose should be pushed slowly over 30-40 seconds.

#toxicology

#neurology


Reference:

Sharbaf Shoar N, Bistas KG, Saadabadi A. Flumazenil. [Updated 2020 Sep 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470180/

Sunday, January 3, 2021

Dopamine and Haldol

 Q:  Haloperidol ______________ the vasodilatory effect of low dose Dopamine (at 1 to 2 mcg/kg/minute)? (select one) 

 A) increases 

B) decreases 

 
Answer: B

The objective of the above question is to highlight the drug interactions which frequently get forgotten under the complicated need for polypharmacy in ICU. The response to Dopamine is dose-dependent At a lower dose of 1 to 2 mcg/kg/minute, it has a vasodilatory effect via dopamine-1 receptors in the renal, mesenteric, cerebral, and coronary beds. Description of all of the effects of Dopamine is beyond the scope of this website.  

Haloperidol is still a common and reflexly ordered drug in ICU. It blunts the vasodilatory effect of Dopamine. The mechanism of action of Haloperidol is by inhibiting dopamine. It is a Dopamine antagonist.


#pharmacology
#cardiology
#psychiatry


References:

1. Dasta JF, Kirby MG. Pharmacology and therapeutic use of low-dose dopamine. Pharmacotherapy 1986; 6:304.

2. Fox CA, Mansour A, Watson SJ Jr. The effects of haloperidol on dopamine receptor gene expression. Exp Neurol. 1994 Dec;130(2):288-303. doi: 10.1006/exnr.1994.1207. PMID: 7867758.

Saturday, January 2, 2021

RSH

 Q: During repair/evacuation of rectus sheath hematoma (RSH) extreme care should be taken to avoid ligation of epigastric vessels? 

 A) True 

 B) False


 Answer: B

Evacuation of RSH in a hemodynamically unstable patient is performed for two reasons. First, to relieve pressure on adjacent abdominal organs, a major cause of intense pain to the patient. The second reason is to ligate the bleeding vessel. Fortunately, in the case of RSH, ligation of either superior or inferior epigastric vessel does not bear any major consequences due to an ample supply of collateral vessels on the ipsilateral side. This blood supply gets reinforced by both superior and inferior epigastric vessels from the contralateral side of the abdomen. 

Hematoma is evacuated once ligation and hemostasis are achieved. Evacuation of RSH leaves a huge dead space. A suction catheter is left in place to remove the inflammatory fluid.

#surgical-critical-care


References:

1. Salemis NS, Gourgiotis S, Karalis G. Diagnostic evaluation and management of patients with rectus sheath hematoma. A retrospective study. Int J Surg 2010; 8:290. 

2. Rimola J, Perendreu J, Falcó J, et al. Percutaneous arterial embolization in the management of rectus sheath hematoma. AJR Am J Roentgenol 2007; 188:W497.