Friday, July 28, 2017

Hyperchloremia Is Associated With Acute Kidney Injury in Patients With Subarachnoid Hemorrhage

Sadan, Ofer; Singbartl, Kai; Kandiah, Prem A.; et al
Critical Care Medicine . 45(8):1382-1388, August 2017.
Abstract:
Objective: To assess the prevalence of acute kidney injury in patients with subarachnoid hemorrhage patients.
Design: Retrospective analysis of all subarachnoid hemorrhage admissions.
Settings: Neurocritical care unit.
Patients: All patients with a diagnosis of subarachnoid hemorrhage between 2009 and 2014.
Interventions: None.
Measurements and Main Results: Of 1,267 patients included in this cohort, 16.7% developed acute kidney injury, as defined by Kidney Disease Improving Global Outcome criteria (changes in creatinine only). Compared to patients without acute kidney injury, patients with acute kidney injury had a higher prevalence of diabetes mellitus (21.2% vs 9.8%; p < 0.001) and hypertension (70.3% vs 50.5%; p < 0.001) and presented with higher admission creatinine concentrations (1.21 ± 0.09 vs 0.81 ± 0.01 mg/dL [mean ± SD], respectively; p < 0.001). Patients with acute kidney injury also had higher mean serum chloride and sodium concentrations during their ICU stay (113.4 ± 0.6 vs 107.1 ± 0.2 mmol/L and 143.3 ± 0.4 vs 138.8 ± 0.1 mmol/L, respectively; p < 0.001 for both), but similar chloride exposure. The mortality rate was also significantly higher in patients with acute kidney injury (28.3% vs 6.1% in the non-acute kidney injury group [p < 0.001]). Logistic regression analysis revealed that only male gender (odds ratio, 1.82; 95% CI, 1.28–2.59), hypertension (odds ratio, 1.64; 95% CI, 1.11–2.43), diabetes mellitus (odds ratio, 1.88; 95% CI, 1.19–2.99), abnormal baseline creatinine (odds ratio, 2.48; 95% CI, 1.59–3.88), and increase in mean serum chloride concentration (per 10 mmol/L; odds ratio, 7.39; 95% CI, 3.44–18.23), but not sodium, were associated with development of acute kidney injury. Kidney recovery was noted in 78.8% of the cases. Recovery reduced mortality compared to non-recovering subgroup (18.6% and 64.4%, respectively; p < 0.001).
Conclusions: Critically ill patients with subarachnoid hemorrhage show a strong association between hyperchloremia and acute kidney injury as well as acute kidney injury and mortality.

Thursday, July 27, 2017

Q: 67 year old female admitted to ICU with CVA. Magnetic Resonance Imaging (MRI has been ordered by Neurology intern. Patient's family informed you that she has dental fillings as well as you saw metal dental braces during exam?


Answer:   MRI does not harm patients with dental fillings and metal braces but it causes image degradation due to artifacts caused by the braces, fillings and wires which appear like a black hole on the image. This is particularly important while scanning  neck, brain or facial area. So it is advisable to remove them if MRI is desired for these areas, but not for chest or lower body areas.

Wednesday, July 26, 2017

Q; 53 year old female with chronic cough but no other major past medical or substance abuse history and otherwise healthy is admitted to ICU with possible pneumonia requiring Non-Invasive-Postive-Pressure-Ventilation (NIPPV). Sputum culture grew M. avium complex (MAC). 
What underlying disease should be suspected?


 Answer: Interstitial Lung Disease (ILD)

MAC pulmonary disease is usually common in malnourished, alcoholics, smokers  or with underlying chronic obstructive lung disease (COPD), prior bronchiectasis, and cystic fibrosis.

Other major group of patient prone to get MAC are nonsmoking women over age 50 who have underlying interstitial disease.


Reference:


Prince DS, Peterson DD, Steiner RM, et al. Infection with Mycobacterium avium complex in patients without predisposing conditions. N Engl J Med 1989; 321:863.

Tuesday, July 25, 2017

Q: Which electrolyte should be watched while patient is receiving piperacillin-tazobactam (Zosyn)?


Answer:  Sodium

Piperacillin-tazobactam carries 'descent amount' of sodium.

2.25 g single-dose vial contains 128 mg of sodium, 
3.375 g single-dose vial contains 192 mg of sodium, and 
4.5 g single-dose vial contains 256 mg of sodium.

Monday, July 24, 2017

Q: Postpneumonectomy pulmonary edema is common after (select one) 

 A) right pneumonectomy 
B) left pneumonectomy


Answer: A

Postpneumonectomy pulmonary edema is more frequent after right pneumonectomy in comparison to left pneumonectomy. Actual cause is not known but various explanations have been put forward such as oxygen toxicity with high FiO2, or not adjusting proper tidal volume for one lung ventilation after surgery. Another explanation could be a reperfusion injury to the remaining lung. Preemptive use of a single intraoperative dose of 250 mg of Solu-Medrol, administered prior to ligation of the pulmonary artery is said to decrease the risk of postpneumonectomy pulmonary edema.


References:

1. Jordan S, Mitchell JA, Quinlan GJ, et al. The pathogenesis of lung injury following pulmonary resection. Eur Respir J 2000; 15:790.

2.Cerfolio RJ, Bryant AS, Thurber JS, et al. Intraoperative solumedrol helps prevent postpneumonectomy pulmonary edema. Ann Thorac Surg 2003; 76:1029. 

Sunday, July 23, 2017

Q: What three simple precautions make visualization of vessel and needle optimum during ultrasound guided central venous cannulation?


Answer:

1. While placing the probe into the sterile sleeve, force any air out. Air bubbles trapped between the probe and the cover  may distort the vessel image on ultrasound screen.

2. Apply additional sterile lubricant gel (or povidone-iodine), between the wrapped probe and the surface of the skin. It will make images crispier.

3. Keep focus on the tip of the needle rather than the needle shaft. Visualization of needle tip can be enhanced by “rocking” the probe forward and backward. It will “flashes” the tip.


Saturday, July 22, 2017

Q: 69 year old male is admitted to ICU for frequent dizziness. After workup, surgery has been consulted for  Carotid Endarterectomy (CEA). Which artery should be selected for cannulation in patients going for CEA?


Answer: 

Patients going for CEA by default have systemic atherosclerotic disease, and difference in blood pressure measurement is frequent in different arms. The arm with the higher cuff blood pressure should be choosen for "A-line". If radials are not readily palpable or cannot be cannulated, the femoral artery with higher cuff blood pressure in corresponding lower extremity should be cannulated.


Reference:

Frank SM, Norris EJ, Christopherson R, Beattie C. Right- and left-arm blood pressure discrepancies in vascular surgery patients. Anesthesiology 1991; 75:457.

Friday, July 21, 2017

Q: What is a type I error and a type II error in bio-statistics? 


Answer:  Proper design is the core to any credible medical study

Type I error (alpha error) is incorrectly concluding that there is a statistically significant difference in collected data - making statistically insignificant conclusion significant. In other words, incorrect rejection of a true null hypothesis.

Type II error (beta error) is incorrectly concluding that there was no statistically significant difference in collected data - making statistically significant conclusion insignificant. In other words,  failure to reject a false null hypothesis.

Thursday, July 20, 2017

Q: Anticoagulation is indicated in patients in which group of Pulmonary Hypertension (PH)? 

A) Group 2

B) Group 3
C) Group 4
D) Group 5
E) all patients with PH irrespective of cause


Answer: C (Group 4)


Group 1 patients receive anticoagulation on case to case basis per clinical judgement.


The World Health Organization (WHO) classifies patients with PH into five groups based upon etiology - and may carry different management plan due to underlying cause of the PH. 

 Group 1 — Patients with group 1 pulmonary arterial hypertension (PAH). It was called idiopathic pulmonary arterial hypertension (IPAH) or primary pulmonary hypertension. It may be hereditary or due to diseases that localize to small pulmonary arterioles, such as connective tissue diseases, HIV, portal hypertension, congenital heart disease, schistosomiasis, and possible drug use. 

 Group 2 — Patients with group 2 have PH secondary to left heart disease including valvular heart disease. This requires underlying cardiac disease management. 

 Group 3 — Patients with group 3 have PH secondary to diseases causing hypoxemia, such as COPD, ILD, sleep-disorders and others. Supplemental oxygen may be a mainstay of treatment. 

 Group 4 — Patients with group 4 PH have due to thromboembolic occlusion of the proximal or distal pulmonary vasculature. In this group anticoagulation is primary medical therapy, at least in earlier stage. 

 Group 5 — Group 5 PH includes with multi-factorial mechanisms like hematologic disorders (eg, myeloproliferative disorders and chronic hemolytic anemia), systemic disorders (eg, sarcoidosis), metabolic disorders (eg, glycogen storage disease), and others. 


References: 

 1. Olsson KM, Delcroix M, Ghofrani HA, et al. Anticoagulation and survival in pulmonary arterial hypertension: results from the Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA). Circulation 2014; 129:57. 

 2. Preston IR, Roberts KE, Miller DP, et al. Effect of Warfarin Treatment on Survival of Patients With Pulmonary Arterial Hypertension (PAH) in the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL). Circulation 2015; 132:2403.

Wednesday, July 19, 2017

Q: What are the three EKG findings which favor Hypertrophic Cardiomyopathy (HCM) over cardiovascular adaptation in an endurance athlete?


Answer:

1. Pathological Q waves (dagger like),
2. Left axis deviation, and
3. T wave inversion



Athlete's heart usually have
  • sinus bradycardia, 
  • increased QRS voltage, 
  • tall peaked T wave, 
  • J point elevation, and 
  • U waves

Tuesday, July 18, 2017

Q: 42 year old female is admitted to ICU with suicidal ideation. ER physician requests ICU bed as he noticed large painful bruises all over the body. Labs were reported normal. In ICU, psychiatric consult was obtained and they come up with the diagnosis of Gardner-Diamond syndrome?


Answer: Gardner-Diamond syndrome is a form of psychogenic purpura, which has taken various names like "hysterical" bleeding, religious stigmata, autoerythrocyte sensitization and painful bruising syndrome. This is typically associated or followed by a psychiatric illness, hard to explain and with essentially normal labs. Physical exam is consist of unexplained painful ecchymotic lesions, mostly on the extremities and/or the face.


References:

1. GARDNER FH, DIAMOND LK. Autoerythrocyte sensitization; a form of purpura producing painful bruising following autosensitization to red blood cells in certain women. Blood 1955; 10:675.

2. Ivanov OL, Lvov AN, Michenko AV, et al. Autoerythrocyte sensitization syndrome (Gardner-Diamond syndrome): review of the literature. J Eur Acad Dermatol Venereol 2009; 23:499.

Monday, July 17, 2017

A note on relationship between fever and ventilator weaning

There is not a huge literature on association between fever and ventilator weaning but weak evidence is available which shows that once temperature goes above 100.4 F (38 C), it may hamper with successful weaning. This may be due to the assumption that fever increases minute ventilation and may increase the work of breathing. There is no real cutoff  of temperature is described above which weaning should be avoided though.



References:

1. Netzer G, Dowdy DW, Harrington T, et al. Fever is associated with delayed ventilator liberation in acute lung injury. Ann Am Thorac Soc 2013; 10:608. 

2. Amoateng-Adjepong Y, Jacob BK, Ahmad M, Manthous CA. The effect of sepsis on breathing pattern and weaning outcomes in patients recovering from respiratory failure. Chest 1997; 112:472.

Sunday, July 16, 2017

Q: 'Phlegmasia cerulea dolens' happens in

A) Deep Venous Thrombosis (DVT)
B) Septic shock
C) Severe Vasoplegia
D) Cholesterol Emboli
E) Diabetic toe


Answer: A

'Phlegmasia cerulea dolens' translates to 'painful blue edema' and is a hallmark of a severe form of DVT which results from extensive thrombotic occlusion of the major and the collateral veins of an extremity. It is characterized by sudden severe pain, swelling, cyanosis and edema of the affected limb. It carries extremely high risk of  massive pulmonary embolism (PE) even though anticoagulation is given. Therefore, invasive vascular intervention is needed. Beneath  this, underlying disease process like Heparin Induced Thrombocytopenia (HIT) or malignancy is always a fear.


References:


1. Sarwar S, Narra S, Munir A. Phlegmasia cerulea dolens. Tex Heart Inst J 2009; 36:76.


2. Barham, Kalleen; Tina Shah (2007-01-18). "Images in Clinical Medicine: Phlegmasia Cerulea Dolens". The New England Journal of Medicine. 356 (3): e3. 

Friday, July 14, 2017

Q: What is the best type of Cardiac MRI to evaluate severity of valvular regurgitation and stenosis? 

 Answer: Flow velocity encoding or phase contrast Cardiac MRI 

Flow velocity encoding Cardiac MRI directly measure blood flow and is useful for quantifying the severity of valvular regurgitation and stenosis, intra-cardiac shunt size, and the severity of arterial vascular stenosis.


Reference:

Beerbaum P, K├Ârperich H, Barth P, et al. Noninvasive quantification of left-to-right shunt in pediatric patients: phase-contrast cine magnetic resonance imaging compared with invasive oximetry. Circulation 2001; 103:2476.

Thursday, July 13, 2017

Q: What is Maastricht classification?

Answer: Non-heart beating donors (NHBDs) are grouped into 5 categories by the Maastricht classification, and divided into controlled and uncontrolled

  • I - Brought in dead - uncontrolled 
  • II - Unsuccessful resuscitation - uncontrolled
  • III - Awaiting cardiac arrest - controlled 
  • IV - Cardiac arrest after brain-stem death - uncontrolled 
  • V - Cardiac arrest in a hospital inpatient - uncontrolled

Categories helped in determining which organs should be procured e.g., only tissues such as heart valves, skin and corneas can be taken from category I donors, but category III donors may have major organs retrieved after cardiac arrest under more controlled and specialized professionals. 


References:

1. Kootstra, G.; Daemen, J.H.; Oomen, A.P. (1995), "Categories of non-heart-beating donors.", Transplantation proceedings, 27 (5): 2893–4

Wednesday, July 12, 2017

Q: A very narrow pulse pressure on the arterial line suggests all of the following except 

 A) aortic regurgitation 
 B) cardiac tamponade 
C) severe cardiogenic shock 
D) massive pulmonary embolism 
E) tension pneumothorax


Answer: A

Aortic regurgitation causes widened pulse pressure, not a narrow pulse pressure, as in diastole, the arterial pressure drops to fill the left ventricle though the regurgitating aortic valve.



Tuesday, July 11, 2017

Q: While inserting radial arterial line, it should be placed as near as possible to radius styloid process

A) True
B) False


Answer:  B (False)

To target appropriate placement of radial arterial line, the best superficial anatomical marker is over the radial pulse at the proximal flexor crease of the wrist. The insertion should be at least 1 cm proximal to the radius styloid process to avoid puncturing the retinaculum flexorum and the small superficial branch of the radial artery.



Monday, July 10, 2017

Q: Why hemodialysis (HD) is more effective than fomepizole in methanol toxicity?


Answer: Early HD may be more effective in methanol toxicity since endogenous clearance of methanol in those treated with fomepizole is slow.



References: 

1.  Gonda A, Gault H, Churchill D, Hollomby D. Hemodialysis for methanol intoxication. Am J Med 1978; 64:749. 

2. Brent J, McMartin K, Phillips S, et al. Fomepizole for the treatment of methanol poisoning. N Engl J Med 2001; 344:424.

Sunday, July 9, 2017

Q: Fasting produces (choose one) 

 A) Hyperkalemia 
B) Hypokalemia


Answer: A

Fasting can increase potassium movement out of the cells due probably due to reduced insulin secretion. It's clinical implication is in patients who are in renal insufficiency or on medicines which can induce hyperkalemia and left NPO in ICU.


References:


1. Allon M. Hyperkalemia in end-stage renal disease: mechanisms and management. J Am Soc Nephrol 1995; 6:1134.


2. Allon M, Takeshian A, Shanklin N. Effect of insulin-plus-glucose infusion with or without epinephrine on fasting hyperkalemia. Kidney Int 1993; 43:212.

Saturday, July 8, 2017

Q: What is the preferred route of epinephrine in anaphylaxis?

A) Intra-Venous (IV)
B) Intra-Muscular (IM)
C) Subcutaneous (SC)
D) Oral
E) Nasal


Answer:  B

IM route is the preferred, both over SC and IV routes. Obviously, over SC, it provides a quicker increase in the plasma and tissue concentrations. IM route is also preferred over IV bolus as IV bolus of "Epi" carries an inherent risk of cardiovascular complications.


References:

1. Simons FE, Gu X, Simons KJ. Epinephrine absorption in adults: intramuscular versus subcutaneous injection. J Allergy Clin Immunol 2001; 108:871.

2. Campbell RL, Bellolio MF, Knutson BD, et al. Epinephrine in anaphylaxis: higher risk of cardiovascular complications and overdose after administration of intravenous bolus epinephrine compared with intramuscular epinephrine. J Allergy Clin Immunol Pract 2015; 3:76.

Friday, July 7, 2017

Q: All of the following cab be used to establish tuberculous pericarditis except? 

A) acid-fast smear/culture 
B) adenosine deaminase concentration 
C) pericardial biopsy 
D) right scalene lymph node biopsy (if lymphadenopathy) 
E) transudative pericardial fluid


Answer: E

Tuberculous pericardial effusion is usually exudative and consist of high protein and increased leukocyte count, with a predominance of lymphocytes and monocytes. Essentially, Light's criteria for exudative pleural effusions can be equally applied for tuberculous pericardial effusion.



Reference: 

 Reuter H, Burgess L, van Vuuren W, Doubell A. Diagnosing tuberculous pericarditis. QJM 2006; 99:827.

Thursday, July 6, 2017

Q: What is anticipatory emesis?

Answer: Anticipatory emesis is a conditioned response mostly in cancer patients who previously had chemotherapy associated significant nausea and vomiting.

For review and further references:

Anticipatory Nausea and Vomiting  - Joseph A. Roscoe, Ph.D., and Et al  - Support Care Cancer. 2011 Oct; 19(10): 1533–1538.

Link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3136579/

Wednesday, July 5, 2017

Q: What is the first line of treatment in severe life-threatening babesiosis?

A) IV Vancomycin
B) PO Doxycycline plus IV Penicillin 
C)  Oral quinine plus intravenous clindamycin
D) IV or oral linezolid
E) Supportive treatment 


Answer: C

Three regimens have been described for the treatment of severe (life-threatening)  babesiosis

1. Oral quinine plus intravenous clindamycin
2. Atovaquone plus azithromycin
3. Atovaquone plus azithromycin plus clindamycin

 Infectious Diseases Society of America (IDSA) guidelines, recommend oral quinine plus intravenous clindamycin as a first line of therapy.


References:

1. Sanchez E, Vannier E, Wormser GP, Hu LT. Diagnosis, Treatment, and Prevention of Lyme Disease, Human Granulocytic Anaplasmosis, and Babesiosis: A Review. JAMA 2016; 315:1767

2. Wittner M, Rowin KS, Tanowitz HB, et al. Successful chemotherapy of transfusion babesiosis. Ann Intern Med 1982; 96:601.

Monday, July 3, 2017

Q: For pregnant women with acute pericarditis, after what age of gestation Nonsteroidal anti-inflammatory drugs (NSAIDs) should be avoided and glucocorticoids should be considered?


Answer:  20 weeks

NSAIDs can be used for pregnant women with acute pericarditis who are less than 20 weeks of gestation. But beyond that NSAIDs should be avoided and glucocorticoids should be considered as a first line of therapy. 
After gestational week 20, NSAIDs may cause constriction of the ductus arteriosus and impair fetal renal function.


Reference:


Adler Y, Charron P, Imazio M, et al. 2015 ESC Guidelines for the diagnosis and management of pericardial diseases: The Task Force for the Diagnosis and Management of Pericardial Diseases of the European Society of Cardiology (ESC)Endorsed by: The European Association for Cardio-Thoracic Surgery (EACTS). Eur Heart J 2015; 36:2921.

Sunday, July 2, 2017

Q: During the acute phase of ischemic stroke (in the first 24 hours) - given there is no risk for aspiration, hemodynamic instability or of increased intracranial pressure - the head of the bed should be kept 

A) 0 - 15 degree 
B) 30 - 45 degrees
C) 90 degrees
D) reverse trendelenburg
E) it does not matter


Answer: A

 During the acute phase of ischemic stroke (in the first 24 hours) - given there is no risk for aspiration, hemodynamic instability or of increased intracranial pressure - the head of the bed should be kept 0 - 15 degrees.  This is best on the hypothesis that cerebral perfusion is maximal when patients are in the horizontal position, as well as to reduce the effect of stenotic vessels and to maximize the collateral flow. But, it should be done after considering all clinical risks particularly aspiration and increased intracranial pressure. Early mobilization and rehab. should be the goal once acute phase is over. Actually, early mobilization during acute phase  (first 24 hours) may be harmful.


References:


1. Schwarz S, Georgiadis D, Aschoff A, Schwab S. Effects of body position on intracranial pressure and cerebral perfusion in patients with large hemispheric stroke. Stroke 2002; 33:497. 

2. Wojner-Alexander AW, Garami Z, Chernyshev OY, Alexandrov AV. Heads down: flat positioning improves blood flow velocity in acute ischemic stroke. Neurology 2005; 64:1354. 

3. AVERT Trial Collaboration group, Bernhardt J, Langhorne P, et al. Efficacy and safety of very early mobilisation within 24 h of stroke onset (AVERT): a randomised controlled trial. Lancet 2015; 386:46.

Saturday, July 1, 2017

Q: What could be the hemodynamic pitfall of placing Dorsalis Pedis Arterial line?


Answer: Potentially dangerous hypotension being missed!

Due to distal systolic pulse amplification, the systolic peak is steeper the further down the arterial vasculature tree blood travels - called “reflected waves” phenomenon. This may give false sense of adequate blood pressure.




 Reference:

 Parry T, Hirsch N, Fauvel N. - Comparison of direct blood pressure measurement at the radial and dorsalis pedis arteries during surgery in the horizontal and reverse Trendelenburg positions. - Anaesthesia. 1995 Jun;50(6):553-5.

Friday, June 30, 2017

Q: What is the clinical utility of "Spin echo imaging" in cardiac magnetic resonance imaging (MRI)? 


 Answer: Cardiac MRI is an umbrella term for various methods to utilize it to evaluate various functions of heart like Spin echo imaging, Steady state free precession imaging, Flow velocity encoding, Magnetic resonance spectroscopy. 

Spin echo imaging shows the tissue structures of the heart as bright and the blood as dark. It provides details of anatomical imaging, and identify the fatty infiltration of the right ventricular free wall to evaluate arrhythmogenic right ventricular cardiomyopathy (ARVC).


Reference:


Menghetti L, Basso C, Nava A, et al. Spin-echo nuclear magnetic resonance for tissue characterisation in arrhythmogenic right ventricular cardiomyopathy. Heart 1996; 76:467.

Thursday, June 29, 2017

Q: What is  “Dead Donor Rule” (DDR)?

Answer: DDR seems simple but it continued to remain a controversial point in medical ethics. DDR implies that a person must be dead before their organs can be taken. This death is considered to be determined by cardiocirculatory criteria,  according to which life-support is withdrawn, an specific time interval of the monitored absence of pulse, blood pressure, and respiration observed, and then death declared. The most accepted time interval in US is according to The Pittsburgh Protocol which requires 2 minutes.


Reference:

Bernat JL (2008). "The boundaries of organ donation after circulatory death". New England Journal of Medicine. 359 (7): 671.

Wednesday, June 28, 2017

Q: Within how many days the resolution of thrombocytopenia should be apparent following withdrawal of heparin in Heparin Induced Thrombocytopeni (HIT)?


Answer:  Within seven days

Though academically seven days are said for the resolution of thrombocytopenia following withdrawal of heparin in HIT patients but pragmatically a trend towards improving platelet count should start happening within three to four days - and if not suspicion for other causes or continue heparin exposure should be looked for.

Monday, June 26, 2017

Q; In patients undergoing abdominal aortic aneurysm repair, where is livedo reticularis is usually located?


Answer: Livedo reticularis due to cholesterol emboli is usually found on the feet and lower legs but in patients undergoing abdominal aortic aneurysm (AAA) repair, livedo reticularis may be found on the back and the buttocks. This is due to the involvement of branches of the internal iliac arteries.