Wednesday, December 13, 2017

Thiazide diuretic and Diabetes

Q: 54 year old male is admitted to ICU with Diabetes Ketoacidosis (DKA). Review of his home medications list showed antihypertensives which includes diuretic therapy. Which of the following diuretic (select one) is found to be associated with the Type 2 Diabetes?

A) Thiazide
B) Furosemide
C) Amiloride 
D) Spironolactone
E) Triamterene


Answer:

It is said the with each 0.5 mEq/L decrease in serum potassium there is a association of  about a 45 percent higher risk of new diabetes. Thiazide diuretics causes a resultant decrease in insulin secretion. Possible mechanism is a failure of potassium channels to close in response to rising plasma glucose concentrations, causing decrease in insulin secretion. On the positive note, this risk can be mitigated by proper potassium supplement or choosing low dose of thiazide diuretics.



References:

1.  Kostis JB, Wilson AC, Freudenberger RS, et al. Long-term effect of diuretic-based therapy on fatal outcomes in subjects with isolated systolic hypertension with and without diabetes. Am J Cardiol 2005; 95:29. 

2. Harper R, Ennis CN, Heaney AP, et al. A comparison of the effects of low- and conventional-dose thiazide diuretic on insulin action in hypertensive patients with NIDDM. Diabetologia 1995; 38:853.

3. Helderman JH, Elahi D, Andersen DK, et al. Prevention of the glucose intolerance of thiazide diuretics by maintenance of body potassium. Diabetes 1983; 32:106. 

4. Shafi T, Appel LJ, Miller ER 3rd, et al. Changes in serum potassium mediate thiazide-induced diabetes. Hypertension 2008; 52:1022. 

5. Zillich AJ, Garg J, Basu S, et al. Thiazide diuretics, potassium, and the development of diabetes: a quantitative review. Hypertension 2006; 48:219.

Dig. toxicity

Q: One vial of digoxin antibody (Fab) fragments binds how much of digoxin?


Answer:   About 0.5 mg of digoxin 

If there is no time to calculate the dose of antibody (Fab) fragments or can't be calculated, 'rule of thumb' is to use 10 vials for adults or 5 vials for children, in acute ingestion of digoxin toxicity.


Reference:

DigiFab package insert. Savage Laboratories. Melville, NY 2004.

Tuesday, December 12, 2017

Jelly Fish Sting (Toxicology)

Q: 24 year old scuba diver is admitted to ICU after jellyfish sting as previously he had a delayed anaphylactic reaction. Patient is complaining of massive burning at the site of sting. Nurse on duty is a wave-surfer. He advised to try topical lidocaine. Besides numbing the effected area, what added advantage lidocaine has in jelly fish sting?


Answer: Lidocaine, also prevents the further nematocyst discharge! And helps to squelch the stinging cells of jellyfish still stuck to the skin. 

Beside lidocaine, other treatments which can be considered for symptomatic relief are ethanol and ammonia. Acetic acid has been used widely but lately fell out of favor.



References:


1.  
Morabito R, Marino A, Dossena S, La Spada G,  "Nematocyst discharge in Pelagia noctiluca (Cnidaria, Scyphozoa) oral arms can be affected by lidocaine, ethanol, ammonia and acetic acid". Toxicon. June 2014:: 83: 52–8.

Monday, December 11, 2017

Suppurative thrombophlebitis

Q: Fungi are more common in peripheral vein suppurative thrombophlebitis than in superior/inferior vena cava suppurative thrombophlebitis?

A) True
B) False


Answer: B

Though common sense may say that fungi should be more common in peripheral vein suppurative thrombophlebitis, but Fungi are more common in superior/inferior vena cava suppurative thrombophlebitis. This is particularly related to total parenteral nutrition (TPN) infusion.


This is again a good reminder of discontinuation of "lines" if they are not needed.


References:

1. Khan EA, Correa AG, Baker CJ. Suppurative thrombophlebitis in children: a ten-year experience. Pediatr Infect Dis J 1997; 16:63.

2. Strinden WD, Helgerson RB, Maki DG. Candida septic thrombosis of the great central veins associated with central catheters. Clinical features and management. Ann Surg 1985; 202:653.

Sunday, December 10, 2017

HIV, TB and ART Treatment

Q: 44 year old male with history of HIV and drug noncompliance presented to ED with mental status change and seizure. CT scan and MRI were promptly done, and patient is transferred to ICU. Astute radiologist called you to say that there appears to be a huge suspicion of tuberculoma in brain. Infectious disease service is consulted. You noticed that though treatment for tuberculous meningitis is written but no orders are written for HIV antiretroviral therapy (ART). Your thoughts?


Answer:  There should be a gap of few weeks between the treatment of tuberculous meningitis and ART. Initiation of ART may be complicated by the immune reconstitution inflammatory syndrome (IRIS), which can manifest as reactivation of latent TB, progression of active TB, or clinical deterioration in patients previously improving on anti-tuberculous therapy. 



References:

1. Nahid P, Dorman SE, Alipanah N, et al. Official American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America Clinical Practice Guidelines: Treatment of Drug-Susceptible Tuberculosis. Clin Infect Dis 2016; 63:e147.

2. Pepper DJ, Marais S, Maartens G, et al. Neurologic manifestations of paradoxical tuberculosis-associated immune reconstitution inflammatory syndrome: a case series. Clin Infect Dis 2009; 48:e96.

3.  Tuon FF, Mulatti GC, Pinto WP, et al. Immune reconstitution inflammatory syndrome associated with disseminated mycobacterial infection in patients with AIDS. AIDS Patient Care STDS 2007; 21:527. 

4. Frequency, severity, and prediction of tuberculous meningitis immune reconstitution inflammatory syndrome. Clin Infect Dis 2013; 56:450.

Saturday, December 9, 2017

"Utley Maneuver"

Q: What is "The little dutch boy maneuver" or the "Utley Maneuver"?



Answer: 

Tracheo-innominate artery fistula is the most dreaded complication of tracheostomy, as tracheal tube tip (or cuff) erodes into the anterior wall of the trachea resulting in a fistula communication with the innominate artery.


Innominate artery passes anteriorly across the trachea.

This is considered to be a clinical diagnosis, as bleeding can be so abrupt and massive that there may not be anytime for diagnostic workup. 

"The little dutch boy maneuver" is a bedside maneuver when a finger can be placed through the tracheostomy stoma, positioned distally into the trachea, and the finger is then pulled anteriorly to compress the artery against the sternum. Substantial pressure should be applied to tamponade the artery (sufficient to lift the torso anteriorly) - till patient can be rushed to OR for emergent repair.

Other less aggressive bedside maneuvers include 
  • overinflation of tracheostomy cuff
  • Oral re-intubation and pass Endotracheal tube (ETT) distal to the tracheostomy site and overinflate the cuff.
During all these high drama scenarios, focus should be maintained on patient's oxygenation either via tube or bag mask ventilation.


Reference:

1. Ridley, R. W.; Zwischenberger, J. B. (2006-08-01). "Tracheoinnominate fistula: surgical management of an iatrogenic disaster". The Journal of Laryngology & Otology. 120 (8): 676–680.

Friday, December 8, 2017

Q; 42 year old female is admitted to ICU due to Mobitz type II second degree AV block. Patient initially presented to ED with cough and fever, but admitted to ICU after astute nurse in ED noted possible AV block on monitor, later confirmed by EKG. You were unable to identify any cause of AV block from her present or family history, list of medications or physical examination. Name few disease processes which should be of your concern?


Answer:
  • Amyloidosis 
  • Sarcoidosis
  • Lyme disease 
  • Endocarditis with abscess formation
  • Hyperkalemia 
  • Hypervagotonia

It may be of interest to know that, in patients under 60 years of age who present with otherwise unexplained or previously undetected heart block, cardiac sarcoidosis has been identified in up to 35 percent of patients.


References:

1. Nery PB, Beanlands RS, Nair GM, et al. Atrioventricular block as the initial manifestation of cardiac sarcoidosis in middle-aged adults. J Cardiovasc Electrophysiol 2014; 25:875. 

2. Takaya Y, Kusano KF, Nakamura K, Ito H. Outcomes in patients with high-degree atrioventricular block as the initial manifestation of cardiac sarcoidosis. Am J Cardiol 2015; 115:505. 

Birnie DH, Sauer WH, Bogun F, et al. HRS expert consensus statement on the diagnosis and management of arrhythmias associated with cardiac sarcoidosis. Heart Rhythm 2014; 11:1305.

Thursday, December 7, 2017

Q: 54 year old male with long standing diabetes travelling from Thailand is admitted to ICU with sepsis, osteomylitis (diabetic foot) and Diabetic-Keto-Acidosis (DKA). Review of his home medications include fusidic acid. 'Charge nurse' ask your advice on possible contact isolation.  Fusidic acid is a  (select one)

A) Steroid antibiotic
B) Adjuvant treatment in Urinary Tract Infections (UTIs)
C) Treatment for gastroesophageal reflux (GERD) disease
D) First line of local cream in burn  patients
E) Decreases pulmonary pressure


Answer: A

 Fusidic acid is a steroid antibiotic which is not approved in USA for use. It is developed sometimes in 1960s and is available worldwide. It is available in injections, topical (cream), eye-drops and oral forms. As resistance to various antibiotics are on rise, there is a renewed interest in its use recently. It is effective primarily on gram-positive bacteria such as Staphylococcus, Streptococcus, and Corynebacterium species. It is bacteriostatic, and so mostly used as an adjunctive treatment. It is effective for use with other antibiotics in chronic osteomyelitis secondary to MRSA; like rifampin and flucloxacillin.



References:


1. Falagas ME, Grammatikos AP, Michalopoulos A. Potential of old-generation antibiotics to address current need for new antibiotics. Expert Rev Anti Infect Ther. 2008; 6(5):593-600 


2. "Fusidic acid in skin and soft tissue infections". International Journal of Antimicrobial Agents. 12 Suppl 2: S59–66. 

3. Howden BP, Grayson ML (2006). "Dumb and dumber—the potential waste of a useful antistaphylococcal agent: emerging fusidic acid resistance in Staphylococcus aureus". Clin Infect Dis. 42 (3): 394–400

Wednesday, December 6, 2017

Q: All of the following are clinical criteria to liberate patient from mechanical ventilation except?

A) Pulseox saturation more than or equal to 90 percent

B) Arterial pH more than 7.30
C) Core temperature 38 to 38.5ºC
D) Hemodynamic stability, without myocardial ischemia
E) Hemoglobin level more than or equal to 7 mg/dL


Answer: B

Collective task force facilitated by the American College of Chest Physicians, the American Association for Respiratory Care, and the American College of Critical Care Medicine, has divided requirements to initiate patient to liberate from ventilators into basic and optional (clinical) criterias.

Basic criteria includes five major components
  • The cause of the respiratory failure has improved
  • Adequate oxygenation
  • Arterial pH more than 7.25
  • Hemodynamic stability
  • Patient is able to initiate an inspiratory effort
Optional criteria includes
  • Hemoglobin level 7
  • No marked fever
  • Adequate mental status

Reference:

MacIntyre NR, Cook DJ, Ely EW Jr, et al. Evidence-based guidelines for weaning and discontinuing ventilatory support: a collective task force facilitated by the American College of Chest Physicians; the American Association for Respiratory Care; and the American College of Critical Care Medicine. Chest 2001; 120:375S.

Tuesday, December 5, 2017

Q: 34 year old female is admitted to ICU after video-assisted thoracoscopic surgery(VATS) due to persistent severe nausea and an episode of vomiting in recovery area. All of the following are predictor of Postoperative Nausea and Vomiting  (PONV) except?

A) complain of nausea and vomiting prior to the surgery 
B) Female gender 
C) Smoking status 
D) Young age
E) History of motion sickness


Answer: C

It may be of interest to know that non-smoking status is an independent risk factor for PONV. As expected, all other choices in the question are good predictors of PONV. 


Female gender is considered to be the strongest overall predictor for PONV.



References:

1. Cohen MM, Duncan PG, DeBoer DP, Tweed WA. The postoperative interview: assessing risk factors for nausea and vomiting. Anesth Analg 1994; 78:7.

2. Stadler M, Bardiau F, Seidel L, et al. Difference in risk factors for postoperative nausea and vomiting. Anesthesiology 2003; 98:46.

3.  Apfel CC, Heidrich FM, Jukar-Rao S, et al. Evidence-based analysis of risk factors for postoperative nausea and vomiting. Br J Anaesth 2012; 109:742.

4. Sinclair DR, Chung F, Mezei G. Can postoperative nausea and vomiting be predicted? Anesthesiology 1999; 91:109.

5. Palazzo M, Evans R. Logistic regression analysis of fixed patient factors for postoperative sickness: a model for risk assessment. Br J Anaesth 1993; 70:135.

Monday, December 4, 2017

Q: All of the following are parts of skin care to avoid pressure ulcer in long term ICU patients except?

A) Keep the skin clean and dry (but avoid excess dryness)
B) Clean the skin cleansing with a pH-balanced cleansing agent 
C) Use the hot water to clean skin
D) Avoid vigorous massage over bony prominences
E)  Keep skin clean from incontinence or wound drainage


Answer: C

Pressure ulcers in long term ICU patients is a major issue. It is extremely underscored. Education of ICU staff including intensivists is lacking in this area.

All of the choices above are true except "C" as hot water will increase damage to the skin.



Related article: 

Pressure Ulcers in the Intensive Care Unit: An Analysis of Skin Barrier Risk Factors -
He, Minjuan BS; & et al  Advances in Skin & Wound Care: November 2016 - Volume 29 - Issue 11 - p 493–498

Link: http://journals.lww.com/aswcjournal/Fulltext/2016/11000/Pressure_Ulcers_in_the_Intensive_Care_Unit___An.6.aspx



Sunday, December 3, 2017

Q: 52 year old male with End Stage Renal Disease is admitted to ICU with fever, hypotension and probable AV graft infection. Infectious Disease (ID) service strongly suspect Infective Endocarditis (IE) but Transesophageal Echocardiography (TEE) failed to provide and definite answer of vegetation. What should be the next step to confirm or rule out Infective Endocarditis(IE)?


Answer: Cardiac CT

If TEE fails to provide definite evidence of IE, the next step is to perform cardiac CT. It is very sensitive, similar in accuracy to detect abscess and pseudoaneurysm, and probably superior to TEE for evaluation of paravalvular extension of infection. It also has an advantage of evaluating the coronary arteries at the same time. From logistic perspective, CT of other parts of the body can be performed at the same time if infective emboli is suspected like to brain or torso.


References:

1. Bruun NE, Habib G, Thuny F, Sogaard P. Cardiac imaging in infectious endocarditis. Eur Heart J 2014; 35:624.

2. Feuchtner GM, Stolzmann P, Dichtl W, et al. Multislice computed tomography in infective endocarditis: comparison with transesophageal echocardiography and intraoperative findings. J Am Coll Cardiol 2009; 53:436. 

Saturday, December 2, 2017

Q: 34 year old female who is on long term peritoneal dialysis for End Stage Renal Disease is admitted to ICU for community acquired pneumonia. Nephrology service decided to continue peritoneal dialysis while patient is in ICU. On third day of admission in ICU peritoneal fluid appeared to be blood stained. Labs including hemoglobin remains stable. Clinically patient continue to show signs of improvement. Your next step?

A) Order serial H/H (Hb and Hematocrit)
B) Obtain CT of abdomen to rule out retroperitoneal hematoma
C) Obtain menstrual history from patient
D) Make her NPO 
E) Order CPK to rule out rhabdomyolysis 


Answer: C

Though there could be other causes of blood stained peritoneal dialysate but in a young female patient who has no other clinical signs of deterioration, the most common cause is menstruation unless proved otherwise! It is either due to ovulation which occurs in mid-cycle or due to endometriosis , where retrograde menstruation could be the reason of blood stained peritoneal dialysate. Alike hematuria, even one cc of blood is enough to give the whole peritoneal dialysate an appearance of blood stained. It requires rapid flushes and instillation of heparin in the dialysate to prevent catheter clotting. Usually, it clears on its own.



References:

1. Tse KC, Yip PS, Lam MF, et al. Recurrent hemoperitoneum complicating continuous ambulatory peritoneal dialysis. Perit Dial Int 2002; 22:488.

2. Dimitriadis CA, Bargman JM. Gynecologic issues in peritoneal dialysis. Adv Perit Dial 2011; 27:101. 

Friday, December 1, 2017

Q: All of the following are the risk factors for refractory vasoplegia after coronary artery bypass grafting (CABG) except?

A) decreased left ejection fraction
B) prolonged aortic cross-clamp times
C) female gender
D) preoperative use of ACE-inhibitors
E) all of the above


Answer: C

Objective of above question is to highlight the dreaded situation of refractory vasoplegia after coronary bypass. Refractory vasoplegia with its domino effect can lead to more complications like postoperative bleeding, acute renal injury (AKI), liver dysfunction, neurologic dysfunction, and prolonged ventilator time.

Males are more prone to vasodilatory shock than females.


References:

1. Kristof AS, Magder S. Low systemic vascular resistance state in patients undergoing cardiopulmonary bypass. Crit Care Med 1999; 27:1121. 

2. Cremer J, Martin M, Redl H, et al. Systemic inflammatory response syndrome after cardiac operations. Ann Thorac Surg 1996; 61:1714. 

Thursday, November 30, 2017

HIV viral load

Q: HIV-1 RNA quantitation (Viral load for HIV) can be misleading in which of the following conditions

A) acute illness 
B) outbreak of herpes simplex infection 
C) vaccination against influenza 
D) vaccination against tetanus
E)  all of the above 


Answer:  E

As patients with HIV infection get admitted to ICU with acute illness frequently, it is of importance to know that viral RNA levels can be misleading and dramatically falsely elevated during acute illness, herpes simplex infection outbreak, or vaccination against many pathogens like influenza, pneumococcus, and tetanus. It takes about a month for values to return to baseline.



References:


1. Donovan RM, Bush CE, Markowitz NP, et al. Changes in virus load markers during AIDS-associated opportunistic diseases in human immunodeficiency virus-infected persons. J Infect Dis 1996; 174:401. 

2. Mole L, Ripich S, Margolis D, Holodniy M. The impact of active herpes simplex virus infection on human immunodeficiency virus load. J Infect Dis 1997; 176:766. 

3. O'Brien WA, Grovit-Ferbas K, Namazi A, et al. Human immunodeficiency virus-type 1 replication can be increased in peripheral blood of seropositive patients after influenza vaccination. Blood 1995; 86:1082. 

4. Staprans SI, Hamilton BL, Follansbee SE, et al. Activation of virus replication after vaccination of HIV-1-infected individuals. J Exp Med 1995; 182:1727.

Wednesday, November 29, 2017

Dexamethasone in Meningitis

Q: Dexamethasone is frequently used as an adjuvant therapy in bacterial meningitis. It should be given (select one)

A)  just before or simultaneously with the first dose of antibiotics
B)  after antibiotics are given


Answer: A

Due to not fully understood reasons, if dexamethasone is given after the administration of antibiotics in suspected bacterial meningitis, the likelihood of an unfavorable outcome is much higher. It can be avoided if antibiotics are already administered.


Reference:


van de Beek D, de Gans J, Spanjaard L, et al. Clinical features and prognostic factors in adults with bacterial meningitis. N Engl J Med 2004; 351:1849.

Tuesday, November 28, 2017

Q: 52 year old male is successfully intubated for impending respiratory failure. Post intubation nurse insert a nasogastric (NG) tube. Follow up x-ray showed NG-tube placed in the post-pyloric area. Your next step (select one)

A) Leave the tube as post-pyloric is ideal place
B) Pull back in gastric area


Answer: B

Post intubation NG tubes are inserted to decompress stomach from possible excessive air from air-mask bagging. There are two other vital reasons for which NG tube should not be allowed to stay in post-pyloric area. (Please note: we are not talking about naso-enteric tube for feeding). Other two reasons are:

1. Leaving NG tube in post-pyloric area may have a potential for electrolyte abnormalities.
2. Relatively, NG tubes are stiffer than enteric tubes used for feeding and may damage the duodenal mucosa.

Monday, November 27, 2017

Q: All of the following are indications to treat suspected digoxin toxicity with digoxin-specific antibody (Fab) fragments except?

A) Life-threatening arrhythmia 
B) Renal dysfunction
C) Neurologic findings
D) Potassium level more than 5 meq/L
E) Elevated liver enzymes (LFT)


Answer: E

Digoxin toxicity in patients on chronic dig therapy is hard to predict, and digoxin level does not correlate with toxicity. Clinical, other laboratory parameters and EKG findings are used to predict 'dig. toxicity'. It can be very life-threatening and usually there is no luxury of time. Benefits usually outweigh risks. All of the above factors can be used to justify the use of digoxin-specific antibody (Fab) fragments, except elevated LFT.



References:

1. Bayer MJ. Recognition and management of digitalis intoxication: implications for emergency medicine. Am J Emerg Med 1991; 9:29. 

2.  Antman EM, Wenger TL, Butler VP Jr, et al. Treatment of 150 cases of life-threatening digitalis intoxication with digoxin-specific Fab antibody fragments. Final report of a multicenter study. Circulation 1990; 81:1744.

Sunday, November 26, 2017

Aortoenteric fistula (AEF)

It is said that the first clinical description of Aortoenteric fistula (AEF) given by Sir Astley Cooper in 1829, remained same for almost two centuries - and has not changed.

"A man with a pulsating tumor seized with discharge of blood by stool and who died suddenly about 12 hours later. At autopsy, the jejunum had adhered to the aneurysmal bag and that sac had ulcerated into the intestine."


Reference:

Cooper A. Lectures on the Principles and Practice of Surgery, London 1829. 

Saturday, November 25, 2017

Warburg effect? (Type B Lactic Acidosis)

Q: What is Warburg effect? (Type B Lactic Acidosis)


Answer: Warburg effect explains the lactic acidosis in tumor cells. It propose that tumor cells shifts their production of energy predominantly to a high rate of glycolysis followed by lactic acid fermentation in the cytosol, resulting in lactic acidosis in cancer patients. Mutations in oncogenes and tumor suppressor genes are thought to be responsible for the Warburg effect.

Dr. Otto Heinrich Warburg,  a German physiologist and a physician was the sole recipient of the Nobel Prize in Physiology or Medicine in 1931. He was nominated for the award 47 times in his life.


References:

1. Friedenberg AS, Brandoff DE, Schiffman FJ. Type B lactic acidosis as a severe metabolic complication in lymphoma and leukemia: a case series from a single institution and literature review. Medicine (Baltimore) 2007; 86:225. 

2. Sia P, Plumb TJ, Fillaus JA. Type B lactic acidosis associated with multiple myeloma. Am J Kidney Dis 2013; 62:633.

Friday, November 24, 2017

Q: During extubation weaning process, evaluation of abdominal muscles represents (Select one) 

A) Inspiratory muscles
B) Expiratory muscles
C)  Neither
D) A and B


Answer: B

Abdominal muscle reflects expiratory muscle strength. The most objective way is to measure gastric pressure, via gastric balloon catheter following maximal cough efforts. Gastric measurement is not a part of everyday ICU clinical practice but objective of above question is to highlight the role of abdominal muscles in the process of respiration specially to watch for these during weaning/extubation process.



Reference: 

Man WD, Kyroussis D, Fleming TA, et al. Cough gastric pressure and maximum expiratory mouth pressure in humans. Am J Respir Crit Care Med 2003; 168:714.

Wednesday, November 22, 2017

Q: 34 year old female with no significant past medical history is admitted to ICU with ischemic stroke, confirmed by CT and follow up MRI in ED. Enthusiastic medical student did proper physical exam and reports the presence of  'livedo reticularis'. What is the most probable diagnosis?

Answer: Anti-phospholipid (aPL) syndrome

It is called “Sneddon's syndrome”. One of the clinical systemic finding (present in about 20% of the patients)  in patients with aPL and an ischemic cerebrovascular disease is livedo reticularis.
Interestingly, after deep vein thrombosis (DVT) and thrombocytopenia, this is the most common clinical finding in patients with aPL. Other clinical findings may be superficial thrombophlebitis, pulmonary embolism and fetal loss. To note, stroke is found to be more common than transient ischemic attack (TIA) in patients with aPL.


 References:

1. Levine SR, Langer SL, Albers JW, Welch KM. Sneddon's syndrome: an antiphospholipid antibody syndrome? Neurology 1988; 38:798.

2. Francès C, Papo T, Wechsler B, et al. Sneddon syndrome with or without antiphospholipid antibodies. A comparative study in 46 patients. Medicine (Baltimore) 1999; 78:209.

3. Cervera R, Piette JC, Font J, et al. Antiphospholipid syndrome: clinical and immunologic manifestations and patterns of disease expression in a cohort of 1,000 patients. Arthritis Rheum 2002; 46:1019.

Tuesday, November 21, 2017

Intubation predictors in GBS

Q: All of the following are the predictors of intubation in Guillain-Barre Syndrome (GBS) Except?

A) Liver enzyme increases
B) Inability to stand
C) Inability to lift the elbows
D) Inability to lift the head
E) Serum creatinine increases


Answer: E

In a large prospective study of 722 patients published in 2003, it showed that out of the following six, if four are present - intubation is predicted in 85% of the cases
  1. Time of onset to admission less than seven days 
  2. Inability to cough 
  3. Inability to stand 
  4. Inability to lift the elbows 
  5. Inability to lift the head 
  6. Liver enzyme increases
Objectively, following parameters are very good predictors of impending respiratory failure and advocate elective intubation in GBS patients
  1. Forced vital capacity less than 20 mL/kg 
  2. Maximum inspiratory pressure less than 30 cmH2O 
  3. Maximum expiratory pressure less than 40 cmH2O

References:

1.  Sharshar T, Chevret S, Bourdain F, et al. Early predictors of mechanical ventilation in Guillain-Barré syndrome. Crit Care Med 2003; 31:278

2. Lawn ND, Fletcher DD, Henderson RD, et al. Anticipating mechanical ventilation in Guillain-Barré syndrome. Arch Neurol 2001; 58:893

Monday, November 20, 2017

Q: What are the five core recommendations from "choosewisely"- Critical Care Societies Collaborative?


Answer: Choosing Wisely® is an initiative of the ABIM (american Board of Internal Medicine) Foundation. Website is www.choosingwisely.org

It works across the board with different societies and entities and to come up with recommendations with four basic objectives

  • Supported by evidence 
  • Not duplicative of other tests or procedures already received 
  • Free from harm 
  • Truly necessary


Following five are the basic recommendations  for critical care from Critical Care Societies Collaborative (here)

1.  Don’t continue life support for patients at high risk for death or severely impaired functional recovery without offering patients and their families the alternative of care focused entirely on comfort.

2. Don’t deeply sedate mechanically ventilated patients without a specific indication and without daily attempts to lighten sedation.

3. Don't use parenteral nutrition in adequately nourished critically ill patients within the first seven days of an ICU stay.

4. Don’t transfuse red blood cells in hemodynamically stable, non-bleeding ICU patients with a hemoglobin concentration greater than 7 g/dL. 

5.  Don’t order diagnostic tests at regular intervals (such as every day), but rather in response to specific clinical questions.

Sunday, November 19, 2017

Colar sign

Q: 24 year old male is admitted via ED to trauma-ICU after motor vehicle accident. Radiology called to inform you that patient has collar sign. What is collar sign?


Answer: The collar sign is also called the hourglass sign. It is mostly present in diaphragmatic rupture. It is due to a waist-like or collar-like appearance of herniated organs at the level of the diaphragm.



Saturday, November 18, 2017

Q: What are the six different types of mechanism for Serotonin Syndrome (SS). Give at least one example of each with  commonly used drug which can precipitate SS?


Answer: Serotonin Syndrome can occur via six ways 

1. Increases serotonin formation -  Tryptophan

2. Increases release of serotonin  - Levodopa

3. Impairs reuptake from the synaptic cleft into the presynaptic neuron - Cocaine, MDMA, Meperidine, Tramadol, selective serotonin reuptake inhibitors (SSRIs)

4. Inhibits serotonin metabolism -  Monoamine oxidase inhibitors e.g linezolid

5. Direct serotonin agonist -  Buspirone,  Fentanyl 

 6. Increases sensitivity of postsynaptic receptor - Lithium


Reference:

Boyer EW, Shannon M. The serotonin syndrome. NEJM 2005; 352:1112.

Friday, November 17, 2017

Q:  69 year old male with previous stroke and dense right sided hemiplegia is admitted to ICU with severe pneumonia requiring intubation and ventilator at 100% FiO2 and high Positive End Expiratory Pressure (PEEP). Complete sedation and neuromuscular blockade is applied. Neuromuscular monitoring is applied with Train of Four (TOF). What one precaution should be taken in this patient?


Answer: Neuromuscular monitoring should not be performed/applied on a paralyzed limb.

In this case TOF should not be measure on right side of the body (with dense hemiplegia). In paralysed muscles, upregulation of acetylcholine receptors occurs after denervation resulting in resistance to nondepolarizing Neuro-Muscular-Blocking-Agents (NMBAs). It gives variable exaggeration of the train-of-four ratio. Consequently, the level of systemic neuromuscular block is usually underestimated if a paretic limb is monitored.


Reference:

1. Moningi S, Durga P, Mantha S, Ramachandra G. Train of four responses in paretic limbs. J Neurosurg Anesthesiol 2009; 21:334. 


Thursday, November 16, 2017

Q: All of the following have shown possible beneficial effect in hepatic encephelopathy except?

A) Plasma aromatic amino acids (AAA)

B) Branched chain amino acids (BCAA)
C) Sodium benzoate 
D) Flumazenil 
E) Zinc


Answer: A

Objective of above question is to highlight the role of Amino Acids in hepatic encephelopathy. Evidence is still weak so this should not be used as standard of treatment, but should be kept in mind if situation requires intervention.

It has been suggested that hepatic failure/insufficiency increases the ratio of plasma aromatic amino acids (AAA) to branched-chain amino acids (BCAA), and can be a contributing cause of hepatic encephalopathy. Increasing the BCAA level may reverse this ratio and helps in preventing or improving hepatic encephelopathy. 

 BCAA is also available as an oral supplement, and may helpful as an adjuvant treatment.

So answer to above question is "A" as Aromatic Amino acid (AAA) can be detrimental. All other choices are of benefits in hepatic encephelopathy. 


References:

1. Gluud LL, Dam G, Les I, et al. Branched-chain amino acids for people with hepatic encephalopathy. Cochrane Database Syst Rev 2017; 5:CD001939. 

2.  Naylor CD, O'Rourke K, Detsky AS, Baker JP. Parenteral nutrition with branched-chain amino acids in hepatic encephalopathy. A meta-analysis. Gastroenterology 1989; 97:1033. 

3. Marchesini G, Dioguardi FS, Bianchi GP, et al. Long-term oral branched-chain amino acid treatment in chronic hepatic encephalopathy. A randomized double-blind casein-controlled trial. The Italian Multicenter Study Group. J Hepatol 1990; 11:92. 

4. Horst D, Grace ND, Conn HO, et al. Comparison of dietary protein with an oral, branched chain-enriched amino acid supplement in chronic portal-systemic encephalopathy: a randomized controlled trial. Hepatology 1984; 4:279. 

5. Les I, Doval E, García-Martínez R, et al. Effects of branched-chain amino acids supplementation in patients with cirrhosis and a previous episode of hepatic encephalopathy: a randomized study. Am J Gastroenterol 2011; 106:1081.

Wednesday, November 15, 2017

Q: About  one-third of patients with Traumatic Brain Injury (TBI) develop possible life threatening coagulopathy. What is the mechanism of action behind it?


Answer: Acute TBI produces systemic release of tissue factor and brain phospholipids into the blood circulation leading to DIC and a consumptive coagulopathy.


Reference:

Zehtabchi S, Soghoian S, Liu Y, et al. The association of coagulopathy and traumatic brain injury in patients with isolated head injury. Resuscitation 2008; 76:52.

Tuesday, November 14, 2017

Q: All of the following can be probable first signs of Malignant Hyperthermia (MH) except 

A) Hyperthermia 
B) Hypercarbia 
C) Sinus tachycardia 
D) Masseter muscle rigidity 
E) Generalized muscle rigidity


Answer: A

There is a huge misconception that hyperthermia is the first sign of MH. Actually not!


Atleast one study showed that hyperthermia was the first sign in MH in only about 8 percent of the cases, and the sole initial sign in about four  percent of cases. 

All other choices in question can be the initial presenting signs in MH.


Reference:

Larach MG, Gronert GA, Allen GC, et al. Clinical presentation, treatment, and complications of malignant hyperthermia in North America from 1987 to 2006. Anesth Analg 2010; 110:498.

Sunday, November 12, 2017

Q: All of the following can cause Type B lactic acidosis except

A) Diabetes mellitus 
B)  Malignancy 
C)  Alcoholism
D)  HIV infection
E)  Short bowel syndrome


Answer:  E

In contrast to type A lactic acidosis, where hypoperfusion is the major cause of lactic acidosis, type B lactic acidosis is mostly due to direct impairment of cellular metabolism.

Short bowel syndrome or other forms of gastrointestinal malabsorption causes type D-lactic acidosis. Large amounts of glucose and starch metabolized  by intestinal bacteria produce D-lactic acid. As humans metabolize D-lactic acid slowly, systemic absorption of the D-isomer of lactic acid leads to high plasma D-lactate and consequently metabolic acidosis.

There is no such thing as type C lactic acidosis.

Bonus pearl: D-lactate levels are not measured by most laboratories so specific orders are needed to run Quantitation of D-lactate level.