Failed pleurodesis

Q: Failed pleurodesis can be predicted by pleural manometry if pleural elastance is? (select one)

A) ≥5 cm H2O per liter of fluid
B) ≥10 cm H2O per liter of fluid
C) ≥15 cm H2O per liter of fluid
D)  ≥20 cm H2O per liter of fluid
E) ≥25 cm H2O per liter of fluid


Answer: D

Pleurodesis requires contact between two layers of a lung to be successful i.e., the visceral and parietal pleurae. Failed pleurodesis is a term applied if a lung failed to fully expand to the chest wall. Various causes include "trapped lung", interstitial pulmonary fibrosis (IPF) or any kind of endobronchial obstruction. In such cases, failed pleurodesis appears as pneumothorax after the procedure. One of the way to predict a failed pleurodesis is using pleural manometry pressure during thoracentesis. Pleural pressure changes is a good surrogate of pleural elastance. A final value for pleural elastance ≥19-20 cm H2O per liter of fluid removed predicts a high likelihood of a failed pleurodesis.

#pulmonary
#procedures


References:

1. Doelken P, Huggins JT, Pastis NJ, Sahn SA. Pleural manometry: technique and clinical implications. Chest 2004; 126:1764. 

2. Feller-Kopman D, Parker MJ, Schwartzstein RM. Assessment of pleural pressure in the evaluation of pleural effusions. Chest 2009; 135:201.

crossreactivity of contrasts

 Q: 58 years old male is admitted to ICU due to Atrial Fibrillation associated Rapid Ventricular Rate (AF-RVR). Patient developed acute abdominal pain after a few hours of admission and requires CT scan with contrast. Patient has a previous history of allergies with shellfish and gadolinium contrast. Your next step of management? (select one)

A) Proceed with CT scan with IV contrast

B) 'Prep' patient with steroid & diphenhydramine  

Answer: A 

'CT scan with IV contrast' is an everyday affair in ICU. There are two objectives to this question. The first is to clarify the misconception that prophylactic 'preps' are needed in IV contrast for CT scan, in cases with hypersensitivity to other compounds including gadolinium contrast as well as shellfish, and topical povidone-iodine solutions. In actuality, in a strict sense, there is no such thing as "iodine allergy", a frequently used misterm. Iodine is a fundamental element in the human body.

The second objective of this case scenario is to emphasize learning the art of risk vs. benefit. In many situations like severe acute abdominal pain as in our patient with AF-RVR, it may be required to 'bite the bullet' and proceed to CT scan. Delay in many clinical situations may be detrimental to the patient.

#allergy-immunology

#radiology

References:

1. Macy EM. Current Epidemiology and Management of Radiocontrast-Associated Acute- and Delayed-Onset Hypersensitivity: A Review of the Literature. Perm J. 2018;22:17-072. doi:10.7812/TPP/17-072 

2. Schabelman E, Witting M. The relationship of radiocontrast, iodine, and seafood allergies: a medical myth exposed. J Emerg Med 2010; 39:701. 

3. Bottinor W, Polkampally P, Jovin I. Adverse reactions to iodinated contrast media. Int J Angiol. 2013;22(3):149-154. doi:10.1055/s-0033-1348885

MG in pregnancy

Q; 32 years old female in the first trimester of pregnancy is admitted to ICU with exacerbation of her Myasthenia Gravis (MG). The patient is started on pyridostigmine. This patient might require? (select one) 

 A) higher dose

 B) lower dose

Answer: A

Pyridostigmine i.e., acetylcholinesterase inhibitors stays the standard first-line treatment for MG in pregnancy. But, it may require a higher dose as renal clearance goes up in pregnancy, there is an expanded maternal blood volume, and frequent emesis. The important thing is to remember to decrease the interval of administration. Later, increase the dose if symptoms persist. Said that caution should be taken to avoid intravenous (IV) pyridostigmine just prior to delivery as it may cause uterine contractions.

#neurology

#ob-GYN

References:

1. Stafford IP, Dildy GA. Myasthenia gravis and pregnancy. Clin Obstet Gynecol 2005; 48:48.

2. Norwood F, Dhanjal M, Hill M, et al. Myasthenia in pregnancy: best practice guidelines from a U.K. multispecialty working group. J Neurol Neurosurg Psychiatry 2014; 85:538. 

3. Sanders DB, Wolfe GI, Benatar M, et al. International consensus guidance for management of myasthenia gravis: Executive summary. Neurology 2016; 87:419.

Echodensity of mitral valve mass

 Q: A low density of mechanical mitral valve mass on echocardiogram favors? (select one)

A) Thrombus

B) Pannus

Answer: A

Echodensity can be described in two ways:

1. Qualitatively - 

• low intensity: similar to myocardial echodensity
• high-intensity: similar to the prosthetic hardware echodensity

 2. Quantitatively -

It is described as using the ratio of the intensity of mass/intensity of prosthesis. A low-intensity mass of ≤0.45 suggests a presumptive diagnosis of thrombus. 

#surgical-critical-care

#cardiology

References:

1. Barbetseas J, Nagueh SF, Pitsavos C, et al. Differentiating thrombus from pannus formation in obstructed mechanical prosthetic valves: an evaluation of clinical, transthoracic and transesophageal echocardiographic parameters. J Am Coll Cardiol 1998; 32:1410. 

2. Lin SS, Tiong IY, Asher CR, et al. Prediction of thrombus-related mechanical prosthetic valve dysfunction using transesophageal echocardiography. Am J Cardiol 2000; 86:1097.

Barbiturate coma - side effects

 Q: Which of the following is NOT a side-effect of pentobarbital induced coma? 

 A) delay in brain death determination 

 B) need of vasopressor 

 C) aadynamic ileus 

 D) risk of ventilator-associated pneumonia 

 E) severe acidosis from ethylene-glycol toxicity 

Answer: E

The induction of barbiturate coma is a common practice in neuro-surgical ICUs. In severe cases of high intracranial pressure (ICP), it helps in decreasing cerebral metabolic demand, Cerebral Blood Flow (CBF), and cerebral blood volume. Its infusion is monitored by continuous electroencephalography (EEG) monitoring, with the objective of a burst-suppression pattern. Barbiturate coma comes with its own price of various side-effects. Due to its very long half-life, there is frequently a delay in brain death determination. Hypotension is a norm and the need for pressor(s) is universal which may lead to arrhythmias as well as organs dysfunction. It also causes ileus. Poor mucus clearance increases the risk for ventilator-associated pneumonia (VAP). Pentobarbital is often prepared in propylene-glycol (not ethylene-glycol - choice E) and longer infusions may result in severe metabolic acidosis.

The objective of the above question is to highlight the dangers of iatrogenic propylene glycol toxicity in ICUs which is used as a diluent in many intravenous infusions including phenytoin, diazepam, and lorazepam besides pentobarbital.

#pharmacology

References:

1. Zosel A, Egelhoff E, Heard K. Severe lactic acidosis after an iatrogenic propylene glycol overdose. Pharmacotherapy. 2010;30(2):219. doi:10.1592/phco.30.2.219 

2. Miller MA, Forni A, Yogaratnam D. Propylene glycol-induced lactic acidosis in a patient receiving continuous infusion pentobarbital. Ann Pharmacother 2008; 42:1502.

3.  Roberts I, Sydenham E. Barbiturates for acute traumatic brain injury. Cochrane Database Syst Rev 2012; 12:CD000033. 

4. Brain Trauma Foundation, American Association of Neurological Surgeons, Congress of Neurological Surgeons, et al. Guidelines for the management of severe traumatic brain injury. XI. Anesthetics, analgesics, and sedatives. J Neurotrauma 2007; 24 Suppl 1:S71.

Vitamins in SIBO

Q: Which of the following may be normal or elevated in a patient with Small Intestinal Bacterial Overgrowth (SIBO) syndrome? 

A) Vitamin A 

B) Vitamin B12 

C) Vitaminn K 

D) Vitamin D

E) Thiamine 

 

Answer: C 

In patients with SIBO, fat malabsorption leads to steatorrhea and deficiencies of fat-soluble vitamins. Vitamin A and D are fat-soluble vitamins. SIBO also leads to Vitamin B12 deficiency due to mucosal damage at the ileal binding site. Thiamine and nicotinamide deficiency occurs from bacterial utilization. In contrast, folate and vitamin K levels are usually either normal or elevated in SIBO patients due to bacterial synthesis. Moreover, increased intestinal permeability also contributes to either normal or elevated vitamin K levels. This may become of clinical importance in a patient who is on warfarin for anti-coagulation.

#gastroenetrology

#hematology

References:

1. Sherman P, Lichtman S. Small bowel bacterial overgrowth syndrome. Dig Dis 1987; 5:157. 

2. Conly J.M. Stein K. Worobetz L. Rutledge-Harding S. The contribution of vitamin K2 (menaquinones) produced by intestinal microflora to human nutritional requirements for vitamin K. Am J Gastroenterol. 1994; 89: 915-923

Ketamine

 Q; In dissociative sedation, a patient retains the spontaneous respirations but not the airway protective reflexes? (select one)

A) True

B) False

Answer: B

Lately, Ketamine use is on increase as a sedative agent in ICUs across the USA. This is is due to its property of causing dissociative sedation. Due to this unique property patient may appear in a trance-like cataleptic state. Ketamine also provides good analgesia. It also causes amnesia. Despite these effects, a patient retains both spontaneous respirations and airway protective reflexes. This makes it useful in non intubated patients as a sedative-infusion or for use in procedural sedation. Ketamine also keeps hemodynamic stability. 

#pharmacology

#sedation-analgesia

References:

1. Umunna BP, Tekwani K, Barounis D, Kettaneh N, Kulstad E. Ketamine for continuous sedation of mechanically ventilated patients. J Emerg Trauma Shock. 2015;8(1):11-15. doi:10.4103/0974-2700.145414 

2. Brown TB, Lovato LM, Parker D. Newton A, Fitton L. Intravenous ketamine for adult procedural sedation in the emergency department: a prospective cohort study. Emerg Med J 2008; 25:498.

3. Patrick M. Wieruszewski, PharmD; Jonathan G. Leung, PharmD, BCPS, BCPP; Sarah Nelson, PharmD, BCPS, BCCCP Ketamine Use in the Intensive Care Unit AACN Adv Crit Care (2018) 29 (2): 101–106. https://doi.org/10.4037/aacnacc2018448

tuberculin test and sarcoid

 Q: 34 years old female with a past medical history of sarcoidosis and recently immigrated from an epidemiological area with a high pulmonary tuberculosis rate is admitted to ICU with community-acquired pneumonia. CXR showed a cavitary lesion. Patient was recently tested negative for "skin TB test" at the workplace. Your next step of management?

A) Isolation

B) No isolation

Answer: A

Sarcoidosis doesn't provide a reliable skin reactivity test for the mycobacterial disease. It is not a good test to screen latent tuberculosis infection. In fact, a positive test is highly diagnostic of mycobacterial disease as sarcoidosis has diminished reactivity to TB (tuberculin) test. In other words, the tuberculin skin test has high specificity but poor sensitivity for tuberculosis in sarcoid patients.

#pulmonary

Reference:

Smith-Rohrberg D, Sharma SK. Tuberculin skin test among pulmonary sarcoidosis patients with and without tuberculosis: its utility for the screening of the two conditions in tuberculosis-endemic regions. Sarcoidosis Vasc Diffuse Lung Dis. 2006 Jun;23(2):130-4. PMID: 17937109.

Commotio cordis

Q: What is Commotio Cordis? 

Answer:  Commotio Cordis is sudden cardiac death due to chest wall impact, usually over the cardiac region. Commotio Cordis is a Latin word that means "agitation of the heart."

The objective of this question is to highlight the fact that despite not well-known, this is one of the very common causes of sudden cardiac death in young athletes. This may be due to projectile balls like in baseball, cricket, or hockey or due to the impact of a body part of other athletes in contact sports like in American football. 

Despite immediate CPR and medical treatment, mortality is very high. It is particularly fatal if the timing of impact corresponds with T-wave, conditioning "R-on-T phenomenon" resulting in ventricular fibrillation.

#cardiology

#sports-medicine

References

1.  Madias C, Maron BJ, Weinstock J, et al. Commotio cordis--sudden cardiac death with chest wall impact. J Cardiovasc Electrophysiol 2007; 18:115. 

2. Maron BJ, Estes NA 3rd. Commotio cordis. N Engl J Med 2010; 362:917. 

3. Kohl P, Nesbitt AD, Cooper PJ, Lei M. Sudden cardiac death by Commotio cordis: role of mechano-electric feedback. Cardiovasc Res 2001; 50:280. 

4. Link MS, Estes NA. Athletes and arrhythmias. J Cardiovasc Electrophysiol 2010; 21:1184. 

Tuberculous peritonitis

 Q: 44 year old male with previous histories of AIDS, cirrhosis, diabetes, underlying Kaposi sarcoma, and renal failure (on continuous ambulatory peritoneal dialysis - CAPD) is admitted in ICU with severe abdominal pain. Subsequent workup diagnosed him with tuberculous peritonitis. Which of his past medical history is the highest risk factor for tuberculous peritonitis?

A) cirrhosis 
B) peritoneal dialysis
C) diabetes mellitus
D) underlying malignancy
E) AIDS

Answer: A

One of the studies has shown the following factors in descending order as risk factors for tuberculous peritonitis. It may be hard to believe that AIDS is the lowest risk factor!

• cirrhosis,
• peritoneal dialysis
• diabetes mellitus
• underlying malignancy
• systemic corticosteroids, and 
• AIDS

#infectious-diseases

Reference:

Chow KM, Chow VC, Hung LC, et al. Tuberculous peritonitis-associated mortality is high among patients waiting for the results of mycobacterial cultures of ascitic fluid samples. Clin Infect Dis 2002; 35:409.

Index card test

 Q: Q: What is 'card test' for extubation?

Answer: Cough strength is considered to be one of the most reliable indicators of successful extubation. Cough strength is usually evident with deep suctioning of the endotracheal tube (ETT). Experts have developed some formal tests and one of the formal tests is the 'card' test. It can be performed by detaching ETT and holding a simple index card at about 2 cm away from the ETT tip. If a patient cannot moisten the card on 3-4 attempts at cough, the likelihood of failed extubation is high.

#ventilators

Reference:

Khamiees M, Raju P, DeGirolamo A, et al. Predictors of extubation outcome in patients who have successfully completed a spontaneous breathing trial. Chest 2001; 120:1262.

Factors in UGI bleed

 Q: Which of the following is likely to be present in upper gastrointestinal (UGI) bleed? (select one)

A) blood urea nitrogen to serum creatinine ratio > 20

B) blood urea nitrogen to serum creatinine ratio > 30 

Answer:  B

Predictive factors for a UGI bleed can be described in Likelihood ratios (LR). Some of the important factors with their LR are below:

• patient's history of melena (LR 5.1-5.9) 
• melenic stool on examination (LR 25)
• blood or coffee-ground material on nasogastric (NG) lavage (LR 9.6)
• ratio of blood urea nitrogen (BUN) to serum creatinine (Cr) >  30 (LR 7.5)
• tachycardia (LR 4.9)
• hemoglobin less than 8 g/dL (LR 4.5-6.2)

#gastroenterology

Reference:

Srygley FD, Gerardo CJ, Tran T, Fisher DA. Does this patient have a severe upper gastrointestinal bleed? JAMA 2012; 307:1072.

Ppl on vent

 Q: The plateau pressure (Pplat or Ppl) on a ventilator is a reflection of static compliance of? (select one)

 A) lung parenchyma 

 B) chest wall

 C) chest wall and abdomen

 D) Lung parenchyma, chest wall and abdomen

Answer: D

The objective of the above question is to emphasize the role of abdominal pressure during ventilation. Excessive focus on the chest/thoracic-cage may keep clinicians away from considering a major role high intraabdominal pressure (IAP) plays in chest mechanics or failed ventilation. Reading Pplat in conjunction with a physical exam, other ventilator parameters, and radiological findings may help in solving this query. 

Unfortunately, there is a dearth of recent literature on this topic, we tried to put some articles together in the reference section.

# ventilators

#pulmonary

References:

1. Richardson JD, Trinkee JK. Hemodynamic and respiratory alterations with increased intra-abdominal pressure. J Surg. 1976;20:401–4.

2. Ridings PC, Bloomfield GL, Blocher GR, Sugerman HJ. Cardiopulmonary effects of raised intra-abdominal pressure before and after intravascular volume expansion. J Trauma. 1995;39:1071–5. 

3. Cullen DJ, Coyle JP, Teplick R, Long MC. Cardiovascular, pulmonary, and renal effects of massively increased intra-abdominal pressure in critically ill patients. Crit Care Med. 1989;17:118–21. 

4. Bloomfield GL, Ridings PC, Blocher CR, Marmaru A, Sugerman HJ. A proposed relationship between increased intra-abdominal, intrathoracic, and intracranial pressure. Crit Care Med. 1997;25:496–503. 

5. Pelosi P, Cereda M, Foti G, Giacomini M, Pesenti A. Alterations of lung and chest wall mechanics in patients with acute lung injury: effects of positive end-expiratory pressure. Am J Respir Crit Care Med. 1995;152:531–7. 

6.  Malbrain ML, Deeren D, Nieuwendiijk R. Partitioning of respiratory mechanics in intra-abdominal hypertension. Intensive Care Med. 2003;29:S85.

7. Anbar JT, Antunes T, Barbas CSV. Influence of PEEP and external abdominal weight in airway and intra-abdominal pressures in mechanically ventilated ICU patients. Am J Respir Crit Care Med. 2005. p. A665. 

8. Mutoh T, Lamm WJ, Embree LJ, Hildebrandt J, Albert RK. Abdominal distension alters regional pleural pressures and chest wall mechanics in pigs in vivo. J Appl Physiology. 1991;70:2611–8

9. Tobin MJ. Respiratory monitoring. JAMA 1990; 264:244. 

10. Marini, JJ. Lung mechanics determinations at the bedside: instrumentation and clinical applications. Respir Care 1990; 35:669.

clonidine

 Q: Describe at least five uses of clonidine besides its use in the treatment of hypertension (HTN)?

Answer: Although Clonidine's main indication is HTN, it has been used successfully (mostly off-label) in many other situations such as

• adjunctive anesthetic sedation and analgesia
• spinal anesthesia
• opioid detoxification
• alcohol withdrawal
• smoking cessation
• postmenopausal hot flashes 
• attention deficit disorder with hyperactivity
• refractory conduct disorder
• sleep disturbances in children 

#pharmacology

References: 

1. Nishina K, Mikawa K, Uesugi T, et al. Efficacy of clonidine for prevention of perioperative myocardial ischemia: a critical appraisal and meta-analysis of the literature. Anesthesiology 2002; 96:323. 

2. Riordan CE, Kleber HD. Rapid opiate detoxification with clonidine and naloxone. Lancet 1980; 1:1079. 

3. Stanley KM, Worrall CL, Lunsford SL, et al. Experience with an adult alcohol withdrawal syndrome practice guideline in internal medicine patients. Pharmacotherapy 2005; 25:1073. 

4. Glassman AH, Stetner F, Walsh BT, et al. Heavy smokers, smoking cessation, and clonidine. Results of a double-blind, randomized trial. JAMA 1988; 259:2863. 

5. Clayden JR, Bell JW, Pellard P. Menopausal flushing: double-blind trial of a non-hormonal medication. Br Med J 1974; 9:490. 

6. Schnoes CJ, Kuhn BR, Workman EF, Ellis CR. Pediatric prescribing practices for clonidine and other pharmacologic agents for children with sleep disturbance. Clin Pediatr (Phila) 2006; 45:229.

TOF

 Q: 72 years old male with previous history of HTN, DM, CAD, previous CABG, alcoholism, and stroke (with some residual hemiplegia on the left side) is admitted with ARDS secondary to severe pancreatitis. Dure to high asynchrony with ventilator, patient required neuromuscular blockade (NMB) along with sedation and analgesia. Which one precaution is required during the application of Train of Four (TOF)?

Answer: Train of Four (TOF) should be avoided on the paralyzed extremity. 

The train of four (TOF) responses, described as T4/T1 ratio are usually exaggerated in paralyzed extremities. In patients who have a previous history of stroke, there is an upregulation of acetylcholine receptors after denervation on the paralyzed limbs. This results in resistance to nondepolarizing NMB agents. The application of TOF gives variable exaggeration of its ratio. This leads to an underestimation of the degree of systemic neuromuscular blocker.

#neurology

References:

1. Moningi, Srilata MD; Durga, Padmaja MD, DNB, PDCC; Mantha, Srinivas MD; Ramachandra, Gopinath MD, FFARCSI, DA Train of Four Responses in Paretic Limbs, Journal of Neurosurgical Anesthesiology: October 2009 - Volume 21 - Issue 4 - p 334-338 doi: 10.1097/ANA.0b013e3181ad4b37 

2. Iwasaki H, Namiki A, Omote K, et al. Response differences of paretic and healthy extremities to pancuronium and neostigmine in hemiplegic patients. Anesth Analg 1985; 64:864.

Eye exam on trauma

 Case: 24 year old female is brought to the trauma Emergency room (ER) after a motor vehicle accident (MVA). She mostly received facial injuries while in the back seat without a seat belt. Patient has no past medical history (PMH) except cosmetic Laser-Assisted In Situ Keratomileusis (LASIK) on her eyes 3 years ago. Patient is complaining of decrease vision and feels something is in her eye. There are also lacerations on both eyelids and requiring pressure to hold the bleeding. What would be your next step?

Answer: Call for an emergent ophthalmic consult

The objective of the above question is to emphasize that the intraocular injuries take precedence over external injuries such as eyelids or canalicular lacerations. Patients with any prior procedures to eyes such as LASIK or cataract surgery increase the risk of an occult rupture, particularly if they complain of decreased visual acuity. 

In case of previous LASIK disruption of the corneal flap may occur and may be visible on an exam. An emergent ophthalmologic consult is required.

#trauma

Reference:

Tsai TH, Peng KL, Lin CJ. Traumatic corneal flap displacement after laser in situ keratomileusis (LASIK) [published correction appears in Int Med Case Rep J. 2017 Jul 26;10 :261]. Int Med Case Rep J. 2017;10:143-148. Published 2017 Apr 19. doi:10.2147/IMCRJ.S128637

electrolytes in SJS/TEN

 Q: Which two electrolytes are considered a good marker of disease severity in Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN)? 

Answer: Serum urea nitrogen and glucose

Contrary to popular belief, eosinophilia is unusual in SJS/TEN. Neutropenia is considered a marker for poor prognosis but it is hard to predict as the administration of steroids obscure neutropenia due to demarginalization and mobilization of neutrophils into the circulation. 

 When it comes to electrolytes, serum urea nitrogen above 28 mg/dL and glucose above 250 mg/dL are considered good markers of disease severity.

#electrolytes

#dermatology

#pharmacology

References:

1. Westly ED, Wechsler HL. Toxic epidermal necrolysis. Granulocytic leukopenia as a prognostic indicator. Arch Dermatol 1984; 120:721. 

2. Bastuji-Garin S, Fouchard N, Bertocchi M, et al. SCORTEN: a severity-of-illness score for toxic epidermal necrolysis. J Invest Dermatol 2000; 115:149.

optimum platelet count for procedures

Q: Optimum threshold of platelet count for epidural anesthesia is? (select one) 

A) 20,000/microL 

B) 50,000/microL 

C) 80,000/microL

Answer: C

Although it is true that the exact threshold of platelet count can not be predicted for any procedure. Usually, 50,000/microL (50K) is considered an optimum number for more or less most of the procedures. The teaching point of this pearl is to highlight the fact that few procedures may require higher than 50K platelets and vice versa. 

Epidural anesthesia is considered a highly invasive procedure and platelet count should be desired at 80,000/microL. Similarly, neuro or ocular surgeries may even require the threshold of 100,000/microL. In contrast, Central Venous Catheter (central line) can be safely performed when done under ultrasound with a platelet count of 20,000/microL. When it comes to patients with hematologic malignancies and immune thrombocytopenia (ITP), the threshold can be even lower such as at 10,000/microL.

#procedures

#hematology

References:

1. Kumar A, Mhaskar R, Grossman BJ, et al. Platelet transfusion: a systematic review of the clinical evidence. Transfusion 2015; 55:1116. 

2. Zeidler K, Arn K, Senn O, et al. Optimal preprocedural platelet transfusion threshold for central venous catheter insertions in patients with thrombocytopenia. Transfusion 2011; 51:2269. 

3. Vavricka SR, Walter RB, Irani S, et al. Safety of lumbar puncture for adults with acute leukemia and restrictive prophylactic platelet transfusion. Ann Hematol 2003; 82:570. 

4. van Veen JJ, Nokes TJ, Makris M. The risk of spinal haematoma following neuraxial anaesthesia or lumbar puncture in thrombocytopenic individuals. Br J Haematol 2010; 148:15.

TCD and brain death

Q:  Change of pattern in blood flow on Transcranial Doppler (TCD) precedes hours before clinical determination of brain death?

A) True

B) False

Answer:   A

The presence of reverberating flow, systolic spikes, or absence of flow in the basilar and both middle cerebral arteries observed in two examinations is highly specific for the prediction of brain death. This reading can be difficult for novices. The objective of this question is to emphasize the utility of TCD in the determination of brain death as a non-invasive, bedside, and quickly available modality. It is interesting to note that changes in TCD blood flow can be preceded in patients with brain death's clinical diagnosis by 6–40 hours.

#neurology

#end-of life-care

Reference:

Li Y, Liu S, Xun F, Liu Z, Huang X. Use of Transcranial Doppler Ultrasound for Diagnosis of Brain Death in Patients with Severe Cerebral Injury. Med Sci Monit. 2016;22:1910-1915. Published 2016 Jun 6. doi:10.12659/msm.899036

osborn wave

Q:  Which electrolyte imbalance may cause Osborn wave on EKG? (select one)

A) Hypokalemia

B) Hyperkalemia

C) Hypocalcemia

D) Hypercalcemia

E) Hypomagnesemia

Answer:  D

Osborn wave on EKG, which is usually a hallmark of hypothermia - and manifest around 32 C / 90 F is due to serum hypercalcemia. It can manifest in any other conditions with hypercalcemia due any other disease pathology. They have also been described after strokes.

#cardiology

Reference: 

Yan GX, Antzelevitch C. Cellular basis for the electrocardiographic J wave. Circulation. 1996 Jan 15;93(2):372-9. doi: 10.1161/01.cir.93.2.372. PMID: 8548912.

pneumothorax ex vacuo

 Q: What is Pneumothorax ex vacuo?

Answer: Pneumothorax ex vacuo can be called a misnomer. It is formed when after thoracentesis the lung stays trapped due to thick fibrous pleural rind, cannot expand, and air filled the space. The exacerbating factor in this phenomenon is the negative pleural pressure created during the procedure. This may pull the air through the track formed by the catheter. Thick fibrous pleural rind may formed due to chronic underlying disease such as atelectasis, bronchial obstruction, an inflammatory or malignant process.

#pulmonary

#procedures

References:

1. Woodring JH, Baker MD, Stark P. Pneumothorax ex vacuo. Chest 1996; 110:1102. 

2. Byrd RP Jr, Roy TM. Pneumothorax ex vacuo. Chest. 1997 Jul;112(1):293-4. doi: 10.1378/chest.112.1.293-a. 

Arterial and venous blood culture

 Q: Venous blood cultures tend to get more contaminated than arterial blood cultures?

A) True

B) False

Answer: False

We were able to find only one small study of 51 patients in the literature which is more than three decades old. So although the evidence is weak, blood cultures obtained either via veins or arteries have the same yield. Said that it does not justify obtaining the blood cultures from the freshly placed arterial lines just for the sake of ease. Blood cultures obtained via catheters have an extremely high ratio (OR=2.69) of being contaminated. This includes freshly placed catheters. If there is no contra-indication, blood cultures should always be obtained through fresh venipuncture, preferably from upper extremity blood vessels.

#infectious-diseases

#procedures

References:

1. Väisänen IT, Michelsen T, Valtonen V, Mäkeläinen A. Comparison of arterial and venous blood samples for the diagnosis of bacteremia in critically ill patients. Crit Care Med 1985; 13:664. 

2. Snyder SR, Favoretto AM, Baetz RA, et al. Effectiveness of practices to reduce blood culture contamination: a Laboratory Medicine Best Practices systematic review and meta-analysis. Clin Biochem 2012; 45:999.

PV and pregnancy

 Q: 32 year old female with a past medical history of Polycythemia Vera (PV) is admitted to ICU after a complication in her first pregnancy with abruptio placentae. You should inform the patient that pregnancy is highly contraindicated in PV? (select one)

A) True

B) False

Answer: B

Despite an increased risk of complications in pregnancy such as miscarriages, abruptio placentae, pre-eclampsia, and intrauterine growth retardation, pregnancy is not a contraindication in patients with PV. A low dose aspirin decreases the rate of pregnancy loss. Patients should be closely monitored throughout the pregnancy. The European LeukemiaNet recommends the target hematocrit either less than 45% or the normal midgestation hematocrit range, whichever is lower. If cytoreduction is needed Interferon alfa is the preferred agent in pregnant women with PV.

#Ob-gyn

#hematology-oncology

References:

1. Barbui T, Barosi G, Birgegard G, et al. Philadelphia-negative classical myeloproliferative neoplasms: critical concepts and management recommendations from European LeukemiaNet. J Clin Oncol 2011; 29:761. 

2. Aggarwal N, Chopra S, Suri V, et al. Polycythemia vera and pregnancy: experience of four pregnancies in a single patient. Arch Gynecol Obstet 2011; 283:393. 

3. Maze D, Kazi S, Gupta V, et al. Association of Treatments for Myeloproliferative Neoplasms During Pregnancy With Birth Rates and Maternal Outcomes: A Systematic Review and Meta-analysis. JAMA Netw Open 2019; 2:e1912666.

"Basedow paraplegia"

 Q: What is "Basedow paraplegia"? 

 Answer: "Basedow paraplegia" is an unusual acute neurological presentation of thyroid storm or in patients with severe hyperthyroidism. The classic presentation is an acute and severe weakness of lower extremities associated with areflexia. Upper extremities though get weak but usually less affected. It is hard to make diagnoses as clinical features may resemble Guillain-Barré syndrome (GBS) which may also occur in severe hyperthyroidism. Treatment is to manage the underlying thyroid pathology.

#endocrinology

#neurology

References:

1. Feibel JH, Campa JF. Thyrotoxic neuropathy (Basedow's paraplegia). J Neurol Neurosurg Psychiatry 1976; 39:491. 

2. Pandit L, Shankar SK, Gayathri N, Pandit A. Acute thyrotoxic neuropathy--Basedow's paraplegia revisited. J Neurol Sci 1998; 155:211.

Getting Sputum culture

 Q: Asking a patient to rinse the mouth prior to obtaining sputum culture increases the optimal yield of the collected material? (select one)

A) True

B) False

Answer: A

A large number of pneumonia patients (almost one-third) cannot produce enough or right sputum specimens, even when they are asked to do under medical supervision. The four best way to increase the optimum yield and improve the quality of the specimen is: 

•  Getting sputum before starting antibiotic treatment 
•  Asking a patient to rinse the mouth before expectoration 
•  NPO couple of hours before expectoration 
•  Inoculate the culture media as soon as quickly preferably at the bedside

#pulmonary

#infectious-diseases

References:

1. Muzanye G, Morgan K, Johnson J, Mayanja-Kizza H. Impact of mouth rinsing before sputum collection on culture contamination. Afr Health Sci. 2009;9(3):200.

2. Bartlett JG, Mundy LM. Community-acquired pneumonia. N Engl J Med 1995; 333:1618. 

psychosis in PD

 Q: 72 year old male with past medical history of Parkinson's Disease (PD) is admitted to ICU with severe psychosis and tendency of hurting himself or others. What are the usual characteristics of severe psychosis in PD?

Answer: Visual hallucinations is the most common psychotic symptom in PD. Unfortunately, it is mostly due to Anti PD drugs. An interesting feature is that patients are mostly cognizant of the fact that their hallucinations are not real. Also, underlying Lewy body disease needs to be ruled out. The second symptom is delusion. Majorly described delusions are spousal infidelity, people stealing money, intruders living in the house, or nurses planning harmful plots.

#psychiatry

#neurology

References:

1. Aarsland D, Brønnick K, Ehrt U, et al. Neuropsychiatric symptoms in patients with Parkinson's disease and dementia: frequency, profile and associated care giver stress. J Neurol Neurosurg Psychiatry 2007; 78:36. 

2. Goetz CG, Wuu J, Curgian LM, Leurgans S. Hallucinations and sleep disorders in PD: six-year prospective longitudinal study. Neurology 2005; 64:81. 

3. Fénelon G, Mahieux F, Huon R, Ziégler M. Hallucinations in Parkinson's disease: prevalence, phenomenology and risk factors. Brain 2000; 123 ( Pt 4):733. 

4. Sanchez-Ramos JR, Ortoll R, Paulson GW. Visual hallucinations associated with Parkinson disease. Arch Neurol 1996; 53:1265.

effects of IABP

 Q: Intra Aortic Balloon Pump (IABP) tends to _____________ the systolic blood pressure? (select one)

A) increase

B) decrease

Answer: B

Inflation of IABP during the heart's diastole displaces the blood to the proximal aorta. And, aortic volume is reduced during systole due to a vacuum effect by rapid balloon deflation (decrease afterload). These two actions result in a decrease in systolic blood pressure,  an increase in diastolic blood pressure, and an increase in mean arterial pressure (MAP).

 All these changes depend on arterial elastance. The higher the arterial elastance, the better the hemodynamic improvement response.

#hemodynamic

Reference:

1. Marchionni N, Fumagalli S, Baldereschi G, et al. Effective arterial elastance and the hemodynamic effects of intraaortic balloon counterpulsation in patients with coronary heart disease. Am Heart J 1998; 135:855.

2. Fried JA, Nair A, Takeda K, Clerkin K, Topkara VK, Masoumi A, Yuzefpolskaya M, Takayama H, Naka Y, Burkhoff D, Kirtane A, Karmpaliotis D, Moses J, Colombo PC, Garan AR. Clinical and hemodynamic effects of intra-aortic balloon pump therapy in chronic heart failure patients with cardiogenic shock. J Heart Lung Transplant. 2018 Nov;37(11):1313-1321. doi: 10.1016/j.healun.2018.03.011. Epub 2018 Mar 20. PMID: 29678608; PMCID: PMC6148415.

Prior use of inhaled glucocorticoids in COPD or asthma patients and parapneumonic effusions

 Q: Prior use of inhaled glucocorticoids in COPD or asthma patients ___________ the chance of parapneumonic effusions? (select one) 

A) decreases 

B) increases 

Answer: A

 Surprisingly, prior use of inhaled glucocorticoids in patients with underlying asthma or chronic obstructive pulmonary disease (COPD) lessens the risk of parapneumonic effusions. Experts are not sure, is this a real phenomenon due to an altered inflammatory response from inhaled glucocorticoids, or these patients have a low threshold to seek medical care early.

#pulmonary

Reference:

1. Sellares J, López-Giraldo A, Lucena C, et al. Influence of previous use of inhaled corticoids on the development of pleural effusion in community-acquired pneumonia. Am J Respir Crit Care Med 2013; 187:1241.

Destruction of RBC

 Q: What percentage of total circulating Red Blood Cells (RBCs) get destruct per day?

Answer: 1%

The basic knowledge of RBC production, destruction, and survival is important while dealing with a patient with acute or chronic anemia. This becomes important when patients stay in ICU for a longer period of time and require blood draws every day.

The formula for RBC turnover rate is 

 RBC turnover rate (percent/day) = 100 ÷ RBC survival (days) 

 In a normal healthy adult, the normal RBC turnover rate is about a percent a day. And, in acute situations, the maximal sustainable capacity of the bone marrow to increase RBC production in an average healthy adult goes high up to 5 percent per day. In children, this turnover can go up to 8 percent in a stressful situation.

#hematology

References:

1. Smith JA. Exercise, training and red blood cell turnover. Sports Med. 1995;19(1):9-31. doi:10.2165/00007256-199519010-00002 

2. Poyart C, Wajcman H. Hemolytic anemias due to hemoglobinopathies. Mol Aspects Med 1996; 17:129. 

3. Handelman GJ, Levin NW. Red cell survival: relevance and mechanism involved. J Ren Nutr. 2010 Sep;20(5 Suppl):S84-8. doi: 10.1053/j.jrn.2010.06.007.

Contrast use in ICU

Q: 65 year old male is recovering in ICU after community-acquired pneumonia. During a physical therapy session, patient injured his shoulder. Orthopedic service requested to order Arthrography. Would you order an intravenous (IV) contrast? (select one)

A) Yes
B) No


Answer: B

The objective of the above question is to highlight the common practice in ICU of ordering contrasts with radiological studies, leading to contrast-induced nephropathy (CIN). For most of the bone Magnetic Resonance Imagings (MRIs),  IV contrast is not needed unless bone tumor or abscess is suspected.  Arthrography of the shoulder requires percutaneous contrast. Ideally, it should be performed under fluoroscopy or ultrasound for proper needle placement. Extravasation of contrast is consistent with a full-thickness rotator cuff tear.

#orthopedic
#trauma
#nephrology


References:

1. Opsha O, Malik A, Baltazar R, et al. MRI of the rotator cuff and internal derangement. Eur J Radiol 2008; 68:36.

2. Lungu E, Moser TP. A practical guide for performing arthrography under fluoroscopic or ultrasound guidance. Insights Imaging. 2015;6(6):601-610. doi:10.1007/s13244-015-0442-9

blood oxygenation during VV ECMO

 Q; What is the good determinant of adequate blood oxygenation in a patient on Veno-venous (VV) Extra Corporeal Membrane Oxygenation (ECMO)?

Answer:

It can be easily estimated by knowing the ECMO Blood Flow/Cardiac Output Ratio. Any value above 60% provides adequate blood oxygenation. 

ECMO Blood Flow is the main determinant of arterial oxygenation in VV ECMO. The 'sweep' gas flow rate provides CO2 elimination. In contrast to other situations in ICU, packed Red Blood Cell (pRBC) transfusion is relatively liberal in ECMO patients, as it increases O2 Delivery.

#ECMO

#hemodynamic

Reference:

1. Schmidt M, Tachon G, Devilliers C, et al. Blood oxygenation and decarboxylation determinants during venovenous ECMO for respiratory failure in adults. Intensive Care Med. 2013;39(5):838-846. doi:10.1007/s00134-012-2785-8