tPA in PE - when to stop

 Q: 52 years old male is admitted to ICU with acute pulmonary embolism (PE) and started on fibrinolytic therapy. Patient started to bleed from femoral site where a central venous catheter (CVC) was placed. No other clinical signs or symptoms witnessed. Bleeding is mostly around the insertion site. Your next line of management? (select one)

A) Stop fibrinolysis infusion

B) Check hemoglobin level

C) Check Fibrinogen level

D) Apply pressure dressing

E) CT scan of the head

Answer: D

The objective of this question is to highlight the fact that minor bleeding is usually expected during fibrinolysis infusion and should be continued as pulmonary embolism can be more fatal. Minor bleeding from venipuncture, arterial puncture sites, in the skin and gums, is usually tolerable - and should be taking care of with local measures (choice D). Minor epistaxis can also be managed with nasal packing. Bleeding from the gastrointestinal or genitourinary tract should also be OK. Infusion of fibrinolysis should be stopped only if there is a sign of hemodynamic instability, neuro signs, a significant drop in hemoglobin with a need for transfusion, or apparent massive bleed. 

Hemoglobin level (choice B) should be checked if there is a concern for massive bleed. Fibrinogen level (choice C) is expected to be low with fibrinolysis therapy, and there is no need to check it.

CT scan of the head (choice E) should be checked only if there is a neuro sign or a concern for neuro-bleed.

#pulmonary

#pharmacology

References:

1. Meyer G, Gisselbrecht M, Diehl JL, et al. Incidence and predictors of major hemorrhagic complications from thrombolytic therapy in patients with massive pulmonary embolism. Am J Med 1998; 105:472. 

2. Sadiq I, Goldhaber SZ, Liu PY, et al. Risk factors for major bleeding in the SEATTLE II trial. Vasc Med 2017; 22:44.

PICCs and DVT

 Q:  What is the maximum limit of the catheter-to-vein ratio advised during insertion of Peripherally Inserted Central Venous Catheters (PICCs)? 

Answer: 45 percent

PICCs are commonly used in ICUs. Clinicians need to be aware of it's increased propensity to cause Deep Venous Thrombosis (DVT). One of the precautions to avoid this complication is to look for catheter-to-vein ratio. Studies have shown that the risk of DVT goes high when the catheter-to-vein ratio goes above 45 percent. If the high-diameter French size catheter placed in a relatively smaller vein, blood will not flow around the catheter leading to coagulation. 

As a rule of thumb, PICCs with size 4 French are safer. Also, single-lumen PICCs are safer than multi-lumen PICCs.

#procedures

References:

1. Evans RS, Sharp JH, Linford LH, et al. Risk of symptomatic DVT associated with peripherally inserted central catheters. Chest 2010; 138:803. 

2. Nifong TP, McDevitt TJ. The effect of catheter to vein ratio on blood flow rates in a simulated model of peripherally inserted central venous catheters. Chest 2011; 140:48. 

3. Sharp R, Cummings M, Fielder A, et al. The catheter to vein ratio and rates of symptomatic venous thromboembolism in patients with a peripherally inserted central catheter (PICC): a prospective cohort study. Int J Nurs Stud 2015; 52:677. 

4. O'Brien J, Paquet F, Lindsay R, Valenti D. Insertion of PICCs with minimum number of lumens reduces complications and costs. J Am Coll Radiol 2013; 10:864.

EPS from anti-psychotics

 Q: Which of the following anti-psychotics is more prone to cause extrapyramidal symptoms (EPS)? (select one) 

 A) Haloperidol 

 B) Quetiapine 

C) Clozapine 

 D) Iloperidone 

 Answer: A

Antipsychotics are frequently used in ICU. Extrapyramidal symptoms (EPS) are common after their use. Extrapyramidal symptoms usually consist of akathisia, parkinsonism, and dystonias. Few well-known antipsychotics to cause EPS are haloperidol, fluphenazine, thiothixene, and trifluoperazine. One of the objectives of this question is to emphasize the side-effect of haloperidol which is still in high use by inpatient clinicians. 

Quetiapine, clozapine, and iloperidone are less intend to cause EPS.

#neurology

#pharmacology

References:

JOHN MUENCH, MD, MPH. ANN M. HAMER, PharmD, BCPP. Adverse Effects of Antipsychotic Medications Am Fam Physician. 2010 Mar 1;81(5):617-622.

C/I to stress test

 Q: All of the following are absolute contraindications for cardiac stress test EXCEPT? (select one)

A) Active endocarditis 

B) Myocardial infarction (MI) within 48 hours 

C) Unstable angina 

D) Acute decompensated heart failure 

E) Hypokalemia with ST-T abnormalities

Answer: E

It is common for a chronically cardiac hospitalized patient to have hypokalemia. There are several relative contraindications/limitations to cardiac stress test. These include Wolff-Parkinson-White (WPW) pattern, paced rhythm, left bundle branch block (L-BBB), chronic digoxin use, severe left ventricular hypertrophy, and hypokalemia showing EKG changes. 

Clinical conditions that can become fatal during the test are considered absolute contraindications. These include the first four choices (A to D) mentioned above as well as a lot of arrhythmia on monitor, hemodynamic instability, severe valvular stenosis, severe myocarditis, severe pericarditis, acute aortic dissection, acute pulmonary embolism (PE), deep venous thrombosis (DVT) and severe physical disability.

#procedures

References:

1. Gibbons RJ, Balady GJ, Bricker JT, et al. ACC/AHA 2002 guideline update for exercise testing: summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1997 Exercise Testing Guidelines). Circulation 2002; 106:1883. 

2. Fletcher GF, Ades PA, Kligfield P, et al. Exercise standards for testing and training: a scientific statement from the American Heart Association. Circulation 2013; 128:873. 

3. Modesto KM, Møller JE, Freeman WK, et al. Safety of exercise stress testing in patients with abnormal concentrations of serum potassium. Am J Cardiol 2006; 97:1247.

Malignant external otitis

 Q; 78 years old male is admitted to ICU with sepsis and visible otorrhea.  Which of the following organism is most likely to be responsible for malignant external otitis? 

 A) Pseudomonas aeruginosa 

 B) Aspergillus 

 C) Staphylococcus 

 D) Klebsiella oxytoca 

 E) Candida parapsilosis

Answer: A

Malignant external otitis is also known as necrotizing external otitis or malignant otitis externa. It is mostly seen in diabetic, elderly, or patients with immunocompromised states such as human immunodeficiency virus (HIV). Almost 95 percent of cases are due to Pseudomonas aeruginosa. It is an invasive infection of the external auditory canal and skull base. All other organisms mentioned above can be culprits but very unlikely.

Interestingly, there are few unique symptoms of this pathology. The pain is usually severe and tends to occur at night. The patient feels pain at the temporomandibular joint while chewing. If such symptoms are associated with visible otorrhea, the likelihood of malignant external otitis is high.

#ID

References:

1. Karaman E, Yilmaz M, Ibrahimov M, Haciyev Y, Enver O. Malignant otitis externa. J Craniofac Surg. 2012 Nov;23(6):1748-51. doi: 10.1097/SCS.0b013e31825e4d9a. PMID: 23147298. 

2. Carfrae MJ, Kesser BW. Malignant otitis externa. Otolaryngol Clin North Am. 2008 Jun;41(3):537-49, viii-ix. doi: 10.1016/j.otc.2008.01.004. PMID: 18435997.

CTM and ETT size

 Q: In emergent cricothyrotomy which size of an endotracheal tube (ETT) is preferred?  (select one)

 A) 6 

 B) 7 

 C) 7.5 

 D) 8 

E) 9 

 Answer: A 

 "Can't intubate, can't oxygenate" is the most dreaded situation for any intensivist. Cricothyroidotomy - also called cricothyrotomy or CTM - is truly a life-saving skill. In such situations, size #6 is preferred. 

ETTs are numbered based on their internal diameter in mm. ETT#6 has an outer diameter of 8-9 mm. Any tube higher than this size may damage the surrounding cartilage. 

But again, in such dire situations, there are no hard and fast rules. Preserving the airway is the goal.

#procedures

References:

1. Langvad S, Hyldmo PK, Nakstad AR, Vist GE, Sandberg M. Emergency cricothyrotomy--a systematic review. Scand J Trauma Resusc Emerg Med. 2013;21:43. Published 2013 May 31. doi:10.1186/1757-7241-21-43 

2. Salvino CK, Dries D, Gamelli R, et al. Emergency cricothyroidotomy in trauma victims. J Trauma 1993; 34:503. 

3. Gupta B, Gupta L. Significance of the outer diameter of an endotracheal tube: a lesser-known parameter. Korean J Anesthesiol 2019; 72:72.

IPS

 Q: "Idiopathic pneumonia syndrome" (IPS) is an/a? (select one) 

A) infectious entity 

B) noninfectious entity

Answer: B

IPS is seen mostly after hematopoietic cell transplantation (HCT). It is more common in allogeneic HCT. It is described as a clinical syndrome evident as widespread alveolar injury and clinical presentation of pneumonia. Patients usually require supplemental oxygen. It is probably a form of interstitial pneumonitis and/or diffuse alveolar damage. It has a very high mortality. There are three basic requirements to qualify for IPS

• widespread alveolar injury with symptoms and signs of pneumonia 
•  absence of active lower respiratory tract infection

Some experts have added a third criteria i.e., absence of cardiac, renal or any other iatrogenic etiology

#oncology

#pulmonary

References:

1. Fukuda T, Hackman RC, Guthrie KA, et al. Risks and outcomes of idiopathic pneumonia syndrome after nonmyeloablative and conventional conditioning regimens for allogeneic hematopoietic stem cell transplantation. Blood 2003; 102:2777

2. Clark JG, Hansen JA, Hertz MI, Parkman R, Jensen L, Peavy HH. NHLBI workshop summary. Idiopathic pneumonia syndrome after bone marrow transplantation. Am Rev Respir Dis. 1993;147(6, pt 1):1601–1606 2. 

3. Panoskaltsis-Mortari A, Griese M, Madtes DK, et al. American Thoracic Society Committee on Idiopathic Pneumonia Syndrome. An official American Thoracic Society research statement: noninfectious lung injury after hematopoietic stem cell transplantation: idiopathic pneumonia syndrome. Am J Respir Crit Care Med. 2011;183(9):1262–1279. 

4. David S. Wenger, Matthew Triplette, et. al. Incidence, Risk Factors, and Outcomes of Idiopathic Pneumonia Syndrome after Allogeneic Hematopoietic Cell Transplantation Biol Blood Marrow Transplant. 2020 Feb; 26(2): 413–420. Published online 2019 Oct 9. doi: 10.1016/j.bbmt.2019.09.034

killip classification

 Q: What is Killip classification? 

 Answer: The Killip classification is one of the cornerstones of prognostic predictors in acute Myocardial Infarction (MI). The following five parameters determine 90% of the prognostic predictors of 30-day mortality in acute MI: 

1.  age 
2.  systolic blood pressure (SBP) on presentation 
3.  Killip classification 
4.  heart rate, and 
5.  anatomic location of the MI 

 Killip classification itself is divided into four classes 

•  class I - no clinical signs of heart failure 
• class II - pulmonary crackles, an S 3 gallop, and elevated jugular venous pressure (JVP) 
• class III - frank acute pulmonary edema 
• class IV - signs of cardiogenic shock including hypotension, oliguria, cyanosis, or impaired mental status

#cardiology

References:

1. Lee KL, Woodlief LH, Topol EJ, et al, for the GUSTO-I investigators. Predictors of 30-day mortality in the era of reperfusion for acute myocardial infarction. Results from an international trial of 41,021 patients. GUSTO-I Investigators. Circulation. 1995 Mar 15. 91 (6):1659-68 

2.  Khot UN, Jia G, Moliterno DJ, et al. Prognostic Importance of Physical Examination for Heart Failure in Non–ST-Elevation Acute Coronary Syndromes: The Enduring Value of Killip Classification. JAMA. 2003;290(16):2174–2181. doi:10.1001/jama.290.16.2174 

3.  Mello BH, Oliveira GB, Ramos RF, et al. Validation of the Killip-Kimball classification and late mortality after acute myocardial infarction. Arq Bras Cardiol. 2014;103(2):107-117. doi:10.5935/abc.20140091

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.

confirming ETT

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

A) True 

B) False 

 Answer: B 

 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.

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.

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: E  (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.

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.

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.

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

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

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.

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.

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.

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.

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.

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/

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.

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.

2021 - Happy New Year

 

Negative pressure rooms

 Q: How frequently air should be changed in negative pressure rooms in ICU?

Answer:  6 to 12 air changes per hour 

Infected particles from respiratory secretions less than 5 microns can stay suspended in the air for a considerable period of time and may get inhaled by people in the surroundings. Airborne precautions are advised for infections like tuberculosis, measles, varicella, smallpox, and SARS viruses (including COVID-19). 

In ICUs airborne isolation is usually done in 'negative pressure rooms'. These rooms should have changed air for at least 6 to 12 times per hour. The door of the room needs to stay closed and caretakers should ideally be wearing N-95 masks. All healthcare workers should be tested for fitting their N-95 masks for a tight seal.

Said that, controversy does exist about negative pressure rooms' efficacy in protecting healthcare workers (see reference # 4).

#infectious-diseases 

Reference: 

1. Jensen PA, Lambert LA, Iademarco MF, et al. Guidelines for preventing the transmission of Mycobacterium tuberculosis in health-care settings, 2005. MMWR Recomm Rep 2005; 54:1.  

2. Wilder-Smith A, Low JG. Risk of respiratory infections in health care workers: lessons on infection control emerge from the SARS outbreak. Southeast Asian J Trop Med Public Health 2005; 36:481. 

3. Miller SL, Clements N, Elliott SA, Subhash SS, Eagan A, Radonovich LJ. Implementing a negative-pressure isolation ward for a surge in airborne infectious patients. Am J Infect Control. 2017 Jun 1;45(6):652-659.  

4. Braude D, Femling J. Dangerous Misperceptions About Negative-Pressure Rooms. Ann Emerg Med. 2020;76(5):690. doi:10.1016/j.annemergmed.2020.05.036

Highe PAOP

 Q: All of the following will have an elevated Pulmonary Artery Occlusion Pressure (PAOP) EXCEPT?

A) Left ventricular systolic heart failure 

B) Hypertrophic cardiomyopathy 

C) Cardiac tamponade 

D) Large pulmonary embolism 

E) Hypervolemia

Answer: D

Pulmonary artery occlusion pressure (PAOP), is also known as pulmonary capillary/artery wedge pressure (PCWP/PAWP). It estimates the left atrial pressure. It is ideally obtained with patient lying supine and at the end of expiration. The tip of the Pulmonary Artery Catheter (PAC) should be in zone 3 of the lung. Mean is obtained of the three previous readings to get the final reading. The balloon of PAC should be inflated while obtaining PAOP. The inflated balloon obstructs the blood flow through pulmonary artery and creates a static column of blood between the catheter tip and the left atrium. The pressure at both ends of the column gets equilibrates i.e., the pressure at the distal end of the catheter is equal to the pressure of the left atrium. Thus, PAOP is a reflection of left atrial pressure and a surrogate of the left ventricular end-diastolic pressure. 

Any condition that raises left ventricular end-diastolic pressure makes PAOP high. This includes left ventricular systolic or diastolic heart failure (choice A), mitral or aortic valve disease,  hypertrophic cardiomyopathy (choice B), cardiac tamponade (choice C), hypervolemia (choice E), and large right-to-left shunts. 

In contrast, conditions that deescalate or take away the pressure from the static column of blood between the catheter tip and the left atrium decreases the PAOP like hypovolemia, pulmonary veno-occlusive disease, or obstructive shock due to large pulmonary embolism (choice D).

We have put the original article on this concept from Drs. Swan and Ganz in the reference section below.

#hemodynamics

References:

1. Swan HJ, Ganz W, Forrester J, et al. Catheterization of the heart in man with use of a flow-directed balloon-tipped catheter. N Engl J Med 1970; 283:447. 

2. Oliveira RK, Ferreira EV, Ramos RP, Messina CM, Kapins CE, Silva CM, Ota-Arakaki JS. Usefulness of pulmonary capillary wedge pressure as a correlate of left ventricular filling pressures in pulmonary arterial hypertension. J Heart Lung Transplant. 2014 Feb;33(2):157-62. doi: 10.1016/j.healun.2013.10.008. Epub 2013 Oct 11. Erratum in: J Heart Lung Transplant. 2014 Apr;33(4):459. de Oliveira, Rudolf K F [corrrected to Oliveira, Rudolf K F]. PMID: 24268673.

Diuretics and hyponatremia

 Q: Which of the diuretic is more prone to cause hyponatremia? (select one)

A) Thiazide

B) Loop

Answer: A

In thiazide diuretics, there is a direct effect of reduced sodium chloride reabsorption without water in the distal tubule, leading to hyponatremia.

Loop diuretics rarely cause hyponatremia. If hyponatremia occurs with loop diuretics, it pinpoints toward other underlying diseases such as congestive heart failure (CHF) or cirrhosis which are by default hyponatremic conditions. This protection of hyponatremia in loop diuretics is because the inhibition of sodium chloride transport in the loop of Henle impairs the generation of the countercurrent gradient. This limits the ability of Anti Diuretic Hormone (ADH) to promote water retention. 

#electrolytes

#nephrology

#pharmacology

References:

1. Szatalowicz VL, Miller PD, Lacher JW, et al. Comparative effect of diuretics on renal water excretion in hyponatraemic oedematous disorders. Clin Sci (Lond) 1982; 62:235. 

2. Filippone EJ, Ruzieh M, Foy A. Thiazide-Associated Hyponatremia: Clinical Manifestations and Pathophysiology. Am J Kidney Dis 2020; 75:256.

Sleep and vent weaning

 Q: Poor sleep quality in ICU leads to prolong weaning from mechanical ventilator? (select)

A) True

B) False

Answer: A

Sleep deprivation has clearly shown to deteriorate the normal respiratory process like hypoxic and hypercapnic chemosensitivity, tongue muscle's (genioglossus) performance, and inspiratory muscles' strength. Sleep studies in ICU have shown poor sleep quality to be associated with prolonged mechanical weaning time, and noninvasive ventilation failure.

#ventilators

References:

1. Thille AW, Reynaud F, Marie D, et al. Impact of sleep alterations on weaning duration in mechanically ventilated patients: a prospective study. Eur Respir J 2018; 51. 

2.  Chen HI, Tang YR. Sleep loss impairs inspiratory muscle endurance. Am Rev Respir Dis 1989; 140:907. 

3. Leiter JC, Knuth SL, Bartlett D Jr. The effect of sleep deprivation on activity of the genioglossus muscle. Am Rev Respir Dis 1985; 132:1242. 

4. Rault C, Sangaré A, Diaz V, et al. Impact of Sleep Deprivation on Respiratory Motor Output and Endurance. A Physiological Study. Am J Respir Crit Care Med 2020; 201:976. 

5. Roche Campo F, Drouot X, Thille AW, et al. Poor sleep quality is associated with late noninvasive ventilation failure in patients with acute hypercapnic respiratory failure. Crit Care Med 2010; 38:477.

Treatment failure in variceal bleed

 Q: 'Treatment Failure' in variceal bleed is defined by all of the following EXCEPT? (select one)

A) More than 100 mL of fresh blood in the nasogastric (NG) aspirate - 2 hours after endoscopic treatment

B) New hypovolemic shock 

C) Drop in hemoglobin of ≥3 g/dL (30 g/L) within 24 hours period

D) Bleeding ≥120 hours after the first hemorrhage, given hemostasis was initially achieved

Answer: D

The objective of this question is to highlight the specific terminologies used in variceal bleed. Variceal bleed and rebleed are two different entities. 

Time zero: – Time of admission. 

 Clinically significant bleeding:  - Transfusion requirement of at least two units of blood within 24 hours of time zero combined with a systolic blood pressure (SBP) less than 100 mmHg, a postural systolic change >20 mmHg, and/or a pulse rate >100 beats per minute at time zero. 

 Acute variceal bleeding: – The time interval from time zero to 120 hours. 

 Treatment failure: Any of the Choices A, B, and C above within 120 hours of time zero 

 Variceal rebleeding - (choice D)

#gastroenterology

Reference:

1. de Franchis R, Baveno V Faculty. Revising consensus in portal hypertension: report of the Baveno V consensus workshop on methodology of diagnosis and therapy in portal hypertension. J Hepatol 2010; 53:762. 

2. de Franchis R, Baveno VI Faculty. Expanding consensus in portal hypertension: Report of the Baveno VI Consensus Workshop: Stratifying risk and individualizing care for portal hypertension. J Hepatol 2015; 63:743. 

3. Tripathi D, Stanley AJ, Hayes PC, et al. U.K. guidelines on the management of variceal haemorrhage in cirrhotic patients. Gut 2015; 64:1680.

severe hyperthermia in SS

 Q: In severe hyperthermia associated with serotonin syndrome which is more effective? (select one) 

A) acetaminophen 

B) neuromuscular blockades 

 Answer: B

Antipyretic agents have no role in hyperthermia associated with serotonin syndrome as this hyperthermia is not hypothalamic regulated. The major reason for hyperthermia in serotonin syndrome is an increase in muscular activity.

This is one of the reasons that in extremely severe hyperthermia (read: only in extremely severe hyperthermia like above 41-degrees centigrade) intubation is preferred so a patient can be sedated well and muscle rigidity can be controlled with a long-acting nondepolarizing neuromuscular blocking agent such as vecuronium. 

Control of hyperthermia and muscle rigidity may prevent all further domino effects like seizures, coma, DIC, V. Tach, and metabolic acidosis.

#neurology

References:

1. Mills KC. Serotonin syndrome. A clinical update. Crit Care Clin 1997; 13:763. 

2. Boyer EW, Shannon M. The serotonin syndrome. N Engl J Med 2005; 352:1112.

electrolyte in hepatic encephelopathy

 Q: Which electrolyte abnormality plays a role in the exacerbation of hepatic encephalopathy? (select one)

A) Hypokalemia

B) Hyponatremia

Answer: A

The presence of hypokalemia makes hepatic encephalopathy worse and should be corrected. Hypokalemia increases renal tubular production of ammonia. This ammonia enters back not only into the tubular lumen but also into the peritubular capillary. This process gets further exacerbated as these patients may also have concurrent metabolic alkalosis, which enhances ammonia's crossing of the blood-brain barrier. 

#hepatology

References:

1. Gabduzda GJ, Hall PW 3rd. Relation of potassium depletion to renal ammonium metabolism and hepatic coma. Medicine (Baltimore) 1966; 45:481. 

2. COOKE RE, SEGAR WE, CHEEK DB, et al. The extrarenal correction of alkalosis associated with potassium deficiency. J Clin Invest 1952; 31:798. 

3.  Artz SA, Paes IC, Faloon WW. Hypokalemia-induced hepatic coma in cirrhosis. Occurrence despite neomycin therapy. Gastroenterology 1966; 51:1046.