Wednesday, January 18, 2017

Q: Harvey-Bradshaw Index (HBI) is a grading system for the severity of which disease? 

A) Crohn Disease

B) Ulcerative Colitis
C) Acute appendicitis
D) Acute Peritonitis
E) Diverticulitis

Answer: A

Crohn's Disease Activity Index (CDAI) is a commonly used grading system to measure the severity of Crohn disease. Harvey-Bradshaw Index (HBI) is created as a simplified version of CDAI.

0-149 points: Asymptomatic remission
150-220 points: Mildly to moderately active Crohn's disease
221-450 points: Moderately to severely active Crohn's disease
451-1100 points: Severely active to fulminant disease

A Harvey-Bradshaw Index of less than 5 correlates with clinical remission.


1. Harvey RF, Bradshaw JM. A simple index of Crohn's disease activity. Lancet. 1980 Mar 8;1(8167):514.

2. Best WR. Predicting the Crohn's disease activity index from the Harvey-Bradshaw Index. Inflamm Bowel Dis. 2006 Apr;12(4):304-10. 

3. Best WR, Becktel JM, Singleton JW, Kern F Jr. Development of a Crohn's disease activity index. National Cooperative Crohn's Disease Study. Gastroenterology. 1976 Mar;70(3):439-44.

Tuesday, January 17, 2017

Q: All of the following are considered as risk factors associated with a poor outcome in acute colonic ischemia except?

A) male gender,
B) SBP less than 90 mm Hg
C) BUN more than 20 mg/dL
D) Hgb less than 8 g/dL
E) LDH more than 350 units/L

Answer: D

As per The American College of Gastroenterology, following are considered as risk factors associated with a poor outcome in acute colonic ischemia and risk stratifications may help in decreasing morbidity and mortality. The risk factors associated with poor outcome described are 
  • male gender, 
  • hypotension (SBP less than 90), 
  • tachycardia (heart rate more than 100 beats/minute), 
  • abdominal pain without rectal bleeding, 
  • blood urea nitrogen (BUN) more than 20 mg/dL, 
  • hemoglobin (Hgb) less than 12 g/dL
  • LDH more than 350 units/L, 
  • serum sodium less than 136 mEq/L, and 
  • WBC more than 15,000/mm3


Brandt LJ, Feuerstadt P, Longstreth GF, et al. ACG clinical guideline: epidemiology, risk factors, patterns of presentation, diagnosis, and management of colon ischemia (CI). Am J Gastroenterol 2015; 110:18.

Monday, January 16, 2017

A note on lactic acid clearance

The two components of lactic acid may very well predict and correlate with ICU mortality.

1) Duration, and
2) Degree

Abramson et al showed more than 23 years ago that if lactic acid normalizes within 24 hours following multiple trauma, survival is 100% predicted. But if it takes more than 48 hours to normalize, survival prediction gets down to only 14%.

Similarly other works have shown that if lactic acid remains elevated more than 4 mmol/L after 24 hours of ICU admission, likelihood of survival is only 11%.


1. Abramson D, Scalea TM, Hitchcock R, Trooskin SZ, Henry SM, Greenspan J. Lactate clearance and survival following injury. J Trauma. 1993 Oct. 35(4):584-8. 

2.  Jones AE. Point: should lactate clearance be substituted for central venous oxygen saturation as goals of early severe sepsis and septic shock therapy? Yes. Chest. 2011 Dec. 140(6):1406-8. 

3. Jones AE, Shapiro NI, Trzeciak S, Arnold RC, Claremont HA, Kline JA. Lactate clearance vs central venous oxygen saturation as goals of early sepsis therapy: a randomized clinical trial. JAMA. 2010 Feb 24. 303(8):739-46.

Sunday, January 15, 2017

Q: What are the potential treatment options for Digoxin's Non-Occlusive Mesenteric Ischemia?

Answer: Digoxin (cardiac glycosides) has shown to cause contraction of vascular smooth muscles, particularly arteriolar vessels. Studies have demonstrated that rapid IV push of digoxin may causes constriction of the splanchnic bed. This effect may get enhanced in the presence of hypokalemia, so inhibition of the Na+-K+-ATPase is suspected as underlying mechanism. As digoxin has slow elimination (not cleared by dialysis either), infusion of papaverine (vasodilator) under angiography guide is recommended as a treatment. Another, relatively simple antidote described is glucagon, which is known to  decrease mesenteric vascular resistance. Similarly, diltiazem is also recommended as a treatment.


1. Bynum TE, Hanley HG (1982) Effect of digitalis on estimated splanchnic blood flow. J Lab Clin Med 99:84–91 

2. Ferrer MI, Bradley SE, Wheeler HO, Enson Y, Presig R, Harvey RM (1965) The effect of digoxin in the splanchnic circulation in ventricular failure. Circulation 32:524–537

3. Hess T, Scholtysik G, Salzmann R, Riesen W (1983) Digoxin-specific antibody fragments and a calcium antagonist for reversal of digoxin-induced mesenteric vasoconstriction. J Pharm Pharmacol 35:647–651 

4. Levinsky RA, Lewis RM, Bynum TE, Hanley HG (1975) Digoxin induced intestinal vasoconstriction. The effects of proximal arterial stenosis and glucagon administration. Circulation 52:130–136 

5. Gasic S, Korn A, Eichler HG (1987), Diltiazem counteracts digitalis-dependent splanchnic vasoconstriction in man. Int J Clin Pharmacol Ther Toxicol 25:553–557

Saturday, January 14, 2017

Q; 52 year old male with history of renal transplant 2 weeks ago is now in ICU for worsening renal failure. The ultrasound report reads "ureteral jets noted in bladder". What does it means? 

Answer: Obstructive uropathy is a common cause of acute kidney injury (AKI) in patients with transplanted kidneys, and one of the common cause is ureteral strictures. For this reason ureteral stents are placed during kidney transplantation. If ultrasound reads that "Ureteral Jets" (pulsatile movement of urine into the bladder) is present, it rules out ureteral obstruction, proved otherwise.

Friday, January 13, 2017

Q: Why it is important to delay bladder catheterization in hemodynamic compromise secondary to suspected right ventricular infarct?

Answer: Bladder catheterization may increase the vagal tone and can decrease preload acutely, leading to cardiogenic shock. Mechanism supposed to be associated is an induction of a parasympathetic autonomic reflex (bradycardia and hypotension) due to a sudden decrease of bladder volume via bladder catheter, while patient is lying supine. 


Mary DA. The urinary bladder and cardiovascular reflexes. Int J Cardiol. 1989;23:11–17

Thursday, January 12, 2017

Q: During thoracentesis, which of the following sign is more predictive of Re-expansion Pulmonary Edema (REPE)  - (Select one)?

A) Chest pain
B) Cough

Answer: A

Usually patients tolerate large volume thoracentesis without REPE. But development of anterior chest pain could be an indicator of REPE. Cough is a very frequent sign during thoracentesis or resolution of pneumothorax but is not as highly associated with REPE as anterior chest pain. In any case, it is recommended to keep volume of thoracentesis less than 1.5 Liters.


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

Tuesday, January 10, 2017

Q: All of the following predicts difficult bag-mask ventilation (BMV) except? 

A) Mask seal
B) Obstruction or Obesity
C) Age over 55 (due to loss of tissue elasticity)
D) presence of teeth
E) Stiff lungs

Answer:  D

Difficult bag-mask ventilation (BMV) can be predicted during intubation with mnemonic MOANS© 
  • Mask seal 
  • Obstruction or Obesity
  • Age over 55 
  • No teeth
  • Stiff lungs
Another Mnemonic commonly used is ROMAN
  • Radiation or Restriction 
  • Obstruction or Obesity or Obstructive Sleep Apnea 
  • Mask Seal or Mallampati or Male 
  • Age 
  • No teeth 
The objective of above question is to highlight the importance of presence or absence of dentures during intubation/BMV. Contrary to popular belief, the presence of teeth is a good sign during intubation for BMV. Teeth provide a good anatomical framework against which the mask can be sealed properly. Patients with denture should be bag mask ventilated with dentures still on and should be removed when an operator is ready to proceed for blade/video laryngoscopy.


 Conlon NP, Sullivan RP, Herbison PG, et al. The effect of leaving dentures in place on bag-mask ventilation at induction of general anesthesia. Anesth Analg 2007; 105:370.
Q: What is MacCallum's patch? 

 Answer: During mitral regurgitation, where the regurgitant jet strikes back the atrial wall, results in endocardial thickening and it is called MacCallum's patch. They are also called MacCallum plaques and also considered as a hallmark in rheumatic heart disease. They are described as "map-like areas of thickened, roughened, and wrinkled part of the endocardium in the left atrium", usually associated with dilated left atrium.

Clinical significance: They are more prone to have vegetations in infective endocarditis.

Monday, January 9, 2017

Q: Which set of arteries usually a cause of massive hemoptysis (select one) 



Though most of the circulation requires passing through the pulmonary vasculature bed but the cause of hemoptysis is usually bronchial arteries, proved otherwise. This is due to the high systolic pressure because of their origin from the aorta (sometimes from the intercostal or vertebral arteries). Another reason is their vital supply to hilar lymph nodes, visceral pleura, and to the mediastinum.


Cahill BC, Ingbar DH. Massive hemoptysis. Assessment and management. Clin Chest Med 1994; 15:147.

Sunday, January 8, 2017

Q: Passive Leg Raise (PLR) testing gives more reliable result when initial hemodynamic data {Cardiac Output (CO) or Pulse-Pressure-Variation (PPV) } is obtained by putting patient at 45 degrees, and obtain hemodynamic data again by

A) Lowering the patient's head to the horizontal position and raise the legs at 45 degrees for about 60-90 seconds

B) Lowering the patient's head to the horizontal position and raise the legs at 90 degrees for about 60-90 seconds

C) Lowering the patient's head to the horizontal position and raise the legs at 45 degrees for about 10-15 seconds.

D) Keep the patient's body to 45 degrees and lower the legs at 90 degrees for about 60-90 seconds

E) PLR testing should be preceded by 500 cc Albumin bolus over 15 minutes, otherwise data is not reliable

Answer: A

PLR test, though easy to perform but is a complex hemodynamic maneuver. It requires proper testing. Answer A is correct as maximal effect occurs at 30-90 seconds. If performed incorrectly, it may lead to erroneous conclusion and may harm the patient. Also, it should be read in conjunction with other maneuver like Pulmonary artery catheter (PAC) data, PPV on arterial line or bedside point of care echo-cardiogram. Also, it should be understand that PLR is more about predicting patient responsiveness to fluid, rather total volume status or ventricular function, though they may important roles. Answer E is wrong as PLR better be performed before IVF bolus.

By definition, a 10 percent increase in CO or decrease in PPV predicts volume responsiveness.

Références and further reading: 

1.  Préau S, Saulnier F, Dewavrin F, Durocher A, Chagnon JL. Passive leg raising is predictive of fluid responsiveness in spontaneously breathing patients with severe sepsis or acute pancreatitis. Crit Care Med. 2010 Mar;38(3):819-25

2. Marik PE, Monnet X, Teboul JL. Hemodynamic parameters to guide fluid therapy. Ann Intensive Care 2011; 1:1. 

3. Mandeville JC, Colebourn CL. Can transthoracic echocardiography be used to predict fluid responsiveness in the critically ill patient? A systematic review. Crit Care Res Pract 2012; 2012:513480. 

4. Cherpanath TG, Hirsch A, Geerts BF, et al. Predicting Fluid Responsiveness by Passive Leg Raising: A Systematic Review and Meta-Analysis of 23 Clinical Trials. Crit Care Med 2016; 44:981. 

5. Bentzer P, Griesdale DE, Boyd J, et al. Will This Hemodynamically Unstable Patient Respond to a Bolus of Intravenous Fluids? JAMA 2016; 316:1298.

Saturday, January 7, 2017

Q: On bedside echo which one other finding may help to rule in cardiac tamponade beside fluid around the heart and diastolic collapse of right ventricle?

Answer: Inferior Vena Cava (IVC) dilatation  without respiratory variations.

IVC dilatation without respiratory variations, reflects the elevated right atrium pressure.

Friday, January 6, 2017

One of the non-pharmacologic strategy to treat atrial fibrillation

Editors' note: has no collaboration with any company. This video is solely for educational purpose

Thursday, January 5, 2017

Q: In Intra-Cranial Hemorrhage (ICH) - which area is more prone to cause seizure?

A) lobar  hemorrhage
B) deep hemorrhage

Answer: A

Contrary to popular belief, seizures are more common in lobar hemorrhage as compared to deep hemorrhage. Monitoring is essential as non-convulsive seizure is not uncommon.


1. Kuramatsu JB, Sauer R, Mauer C, et al. Correlation of age and haematoma volume in patients with spontaneous lobar intracerebral haemorrhage. J Neurol Neurosurg Psychiatry 2011; 82:144.

2. Broderick J, Connolly S, Feldmann E, et al. Guidelines for the management of spontaneous intracerebral hemorrhage in adults: 2007 update: a guideline from the American Heart Association/American Stroke Association Stroke Council, High Blood Pressure Research Council, and the Quality of Care and Outcomes in Research Interdisciplinary Working Group. Stroke 2007; 38:2001.

Wednesday, January 4, 2017

Q: what is the physiology behind "alimentary hypoglycemia" in patients with dumping syndrome after gastric bypass surgery?

Answer: In patients with gastric surgery, the rapid "dumping" of food triggers the pancreas to release excessive amounts of insulin and to cause "alimentary hypoglycemia." To note, it has also been reported without any history of gastric surgery 1.


1. M. Alan Permutt, M.D., John Kelly, M.D., Robert Bernstein, M.D., David H. Alpers, M.D., Barry A. Siegel, M.D., and David M. Kipnis, M.D. - Alimentary Hypoglycemia in the Absence of Gastrointestinal Surgery -  N Engl J Med 1973; 288:1206-1210 - June 7, 1973

Tuesday, January 3, 2017

Q: Which antihypertensive medicine has shown to reverse the myoclonus effect of opioid analgesics?

Answer: Nifedipine

Nifedipine, also popularly known by its trade name Procardia is known to reverse the myoclonus effect of opioids. The Dose is 10 mg three times per day. Another drug which may help is Clonazepam in a dose of 0.5 mg three times per day.

Monday, January 2, 2017

Q: After new year night fireworks, 20 year old male is admitted via ED with partial-thickness burns greater than 10% of Total Body Surface Area (TBSA). Why it is important to give constant rate of IVF depending upon calculated fluid requirement (using either Parkland or the modified Brooke formula), and avoid intermittent IV fluid boluses? 

 Answer: Giving IVF boluses instead of constant rate IVF for volume resuscitation in burn patients, may cause vascular collapse and increase the edema. 


 Gueugniaud PY, Carsin H, Bertin-Maghit M, Petit P. Current advances in the initial management of major thermal burns. Intensive Care Med 2000; 26:848.

Sunday, January 1, 2017

Q: All of the following can be used in cardiac complications of cocaine toxicity except?

A) nitroglycerin
B) benzodiazepines
C) aspirin  
D) phentolamine
E) beta-blocker 

Answer: E

Objective of above question is to reinforce the contraindication of beta-blockers in acute cocaine ingestion, as well as to highlight the benefit of phentolamine. Phentolamine is an alpha-adrenergic antagonist and is very effective as a second agent in reversing cocaine-induced coronary artery vasoconstriction in unresponsive benzodiazepines. It is given as IV bolus in a dose of 1 to 2.5 mg every 5 to 10 minutes on PRN basis.


1. Lange RA, Hillis LD. Cardiovascular complications of cocaine use. N Engl J Med 2001; 345:351.

2. Hollander JE. The management of cocaine-associated myocardial ischemia. N Engl J Med 1995; 333:1267. 

3. Albertson TE, Dawson A, de Latorre F, et al. TOX-ACLS: toxicologic-oriented advanced cardiac life support. Ann Emerg Med 2001; 37:S78.

Saturday, December 31, 2016

Q: 32 year old male presented to ED after new year Friday night party with chest pain and hypertension. He admits using Cocaine. Initial labs showed hypokalemia of 2.9 mEq/L. What would be your concern?

Answer: Clenbuterol

Clenbuterol is an adulterant frequently found in cocaine and heroin. Clenbuterol tends to cause  a tetrad of 
  • tachycardia 
  • hyperglycemia 
  • palpitations, and 
  • hypokalemia
Also, it may cause  nausea, hypo or hypertension, thyrotoxicosis, chest pain, venous hyperoxia but with lactic acidosis, central symptoms of agitation and anxiety. 

Treatment is supportive.


 Centers for Disease Control and Prevention (CDC). Atypical reactions associated with heroin use--five states, January-April 2005. MMWR Morb Mortal Wkly Rep 2005; 54:793.

Friday, December 30, 2016

Q; All of the following are indications of starting hemodialysis (HD) in patients with Chronic Kidney Disease: (CKD) :

A) Pericarditis 
B) Pleuritis
C) Wrist or foot drop
D) Seizures
E) All of the above

Answer: E

Fluid overload, acidosis, hyperkalemia and other electrolyte disturbances are well known indications of emergent HD. But some of the manifestations of CKD and/or uremia are under-appreciated where relatively urgent intervention is needed like pericarditis or pleuritis, encephalopathy manifesting as confusion, asterixis, myoclonus, wrist or foot drop, or, even seizures. Also uncontrolled uremic bleeding diathesis may require HD sooner than later.


 Hemodialysis Adequacy 2006 Work Group. Clinical practice guidelines for hemodialysis adequacy, update 2006. Am J Kidney Dis 2006; 48 Suppl 1:S2.

Thursday, December 29, 2016

Q; How order for analgesia should be written, differently in dying patient over non-dying patients?

Answer:  As well known, narcotics are the mainstay of analgesia in end of life (dying) patients. But as dying patients may be frail to ask for medicine, instead of writing PRN (as needed), it should be written as either “offer, may refuse” or “as scheduled for symptoms”.

Wednesday, December 28, 2016

Q: How Guanylate cyclase (sGC)stimulant (Riociguat) (trade name = Adempas) works for thromboembolic Pulmonary hypertension? 

Answer: It has a dual mode of action.

1. Increases the sensitivity of sGC to endogenous nitric oxide (NO)
2. Directly stimulate the receptor to mimic the action of NO

It should be used with extreme caution in patients who are already on nitrates and phosphodiesterase inhibitors.


1. Rubin LJ, Galiè N, Grimminger F, et al. Riociguat for the treatment of pulmonary arterial hypertension: a long-term extension study (PATENT-2). - Eur Respir J 2015; 45:1303. 

2. Ghofrani HA, Galiè N, Grimminger F, et al. Riociguat for the treatment of pulmonary arterial hypertension. N Engl J Med 2013; 369:330.

Tuesday, December 27, 2016

Q: With recent advances in laboratory technology, which one precaution should be taken while interpreting the labs in diabetic ketoacidosis (DKA)?

Answer:  The sodium is traditionally corrected by 1.6 mEq/L for every 100 mg/dL increase in serum glucose, above 100 mg/dL. Some experts prefer adjustment of 2.4 mEq/L. But with recent advances in technology, many labs now report actual sodium. Correcting reported actual sodium with increased glucose level may give a wrong result of plasma osmolality and may lead to erroneous IVF replacement in DKA. It should be checked with local hospital labs personnel.

Saturday, December 24, 2016

Q: How to calculate the Plasma Exchange volume for plasmapheresis?


Usually, one plasma volume exchange is performed per procedure, which is expected to remove most of the target substance. There are two ways to calculate

1. Rule of thumb: In a regular adult person (70 kg) just use 3 liters of replacement fluid.

2. Use the formula 
    Estimated plasma volume (in liters) = 0.07 x weight (kg) x (1 - hematocrit) 

 To recap, plasmapheresis is a universal term used for removal of plasma from the blood using either centrifugation or filtration. In general population, it is used to collect plasma (plasma donation). Therapeutic plasma exchange means removal of patient plasma and replacement with another fluid (donor plasma, colloid, crystalloid). 


Kaplan AA. A simple and accurate method for prescribing plasma exchange. ASAIO Trans 1990; 36:M597.

Friday, December 23, 2016

Q: Continuous infusion and bolus intravenous loop diuretic overall carries same efficacy in heart failure (CHF) patients. Beside, less chances of ototoxicity, what other advantage continuous infusion of loop diuretic may have over IV bolus in CHF patients? 

Answer: It helps in maintaining sodium level

Continuous intravenous infusion maintains an effective rate of drug excretion, and  inhibits sodium chloride reabsorption in the loop of Henle. IV bolus doses of loop diuretics, as expected are associated with higher and then lower rate of drug excretion, causing unreliable maintenance of sodium chloride hemostasis.


 1. Rudy DW, Voelker JR, Greene PK, et al. Ann Intern Med 1991; 115:360. 

2.  Brater DC, Day B, Burdette A, et al. Kidney Int 1984; 26:183

Thursday, December 22, 2016

Q: Should angiotensin-converting enzyme inhibitor (ACE-I) or angiotensin receptor blockers (ARBs) be hold to prevent Contrast Induced Nephropathy (CIN)? (Select one)

A) Yes
B) No
C) Not Clear

Answer: C

There is no convincing evidence present in literature to support the idea of withholding ACE inhibitors and/or ARBs to prevent CIN. Most of the time, it is done reflexly. Actually, they have been suggested as rather helpful,  by blocking renin-angio II vasoconstriction. 

It should be done only on case to case basis - and should not be held in mild renal insufficiency.


1. Rim MY, Ro H, Kang WC, et al. The effect of renin-angiotensin-aldosterone system blockade on contrast-induced acute kidney injury: a propensity-matched study. Am J Kidney Dis 2012; 60:576. 

2. Rosenstock JL, Bruno R, Kim JK, et al. The effect of withdrawal of ACE inhibitors or angiotensin receptor blockers prior to coronary angiography on the incidence of contrast-induced nephropathy. Int Urol Nephrol 2008; 40:749.

Wednesday, December 21, 2016

Q: In last few years cough strength has been advocated as one of the weaning parameter. How cough strength can be objectively measured?

Answer: After inserting a spirometer into the ventilator circuit, and then patient instructed to cough, the peak expiratory flow (PEF) is measured. If PEF less than 60 L/min, chances of extubation failure is high. 


1. Smina M, Salam A, Khamiees M, et al. Cough peak flows and extubation outcomes. Chest 2003; 124:262.

2. Salam A, Tilluckdharry L, Amoateng-Adjepong Y, Manthous CA. Neurologic status, cough, secretions and extubation outcomes. Intensive Care Med 2004; 30:1334.

Tuesday, December 20, 2016

Q: Due to its laminar flow, Heliox is more effective (Select one) 

 A) in the small airways 
 B) in the large airways

Answer: B

Heliox, though has a similar viscosity to air but a significantly lower density. In the small airways, resistance is proportional to gas viscosity so Heliox has lesser impact. Moreover, in smaller airways flow is laminar anyway. 

In the large airways, Heliox's low density produces a higher laminar flow in comparison to turbulent flow of air. Laminar flow generates less resistance. Also, in the large airways where flow is turbulent, resistance is proportional to density, so heliox has a significant clinical impact.

Monday, December 19, 2016

(often missed in ICU is ophthalmic care!) 

 Protocolized eye care prevents corneal complications in ventilated patients in a medical intensive care unit

Background: Eye care is an essential component in the management of critically ill patients. Standardized eye care can prevent corneal complications in ventilated patients.

Objective: This study was designed to compare old and new practices of corneal care for reduction in corneal complications in ventilated patients.

Methods: This study was done in three phases each of six month duration. Phase 1 was the ongoing practice of eye care in the unit. Before the start of phase 2, a new protocol was made for eye care. Corneal complications were observed in terms of haziness, dryness, and ulceration. All nursing staffs were educated and made compliant with the new protocol. In phase 2, a follow-up audit was done to check the effectiveness and compliance to protocol. In phase 3, a follow-up audit was started 3 months after phase 2.

Results: In phase 1, total ventilated patients were 40 with 240 ventilator days. The corneal dryness rate was 40 per 1000 ventilator days while the haziness and ulceration rate was 16 per 1000 ventilator days each. In the second phase 2, total ventilated patients were 53 making 561 ventilator days. The rate of corneal haziness and dryness was 3.52 and 1.78 per 1000 ventilator days, respectively, with no case of corneal ulceration. In phase 3, the number of ventilated patients was 91 with 1114 ventilator days. The corneal dryness rate was 2.69 while the haziness and ulceration rate was 1.79 each.

Conclusion: Protocolized eye care can reduce the risk of corneal complications in ventilated patients.


Mohammad Feroz Azfar, Muhammad Faisal Khan, and Abdulaziz H. Alzeer - Protocolized eye care prevents corneal complications in ventilated patients in a medical intensive care unit - Saudi J Anaesth. 2013 Jan-Mar; 7(1): 33–36.

Sunday, December 18, 2016

(One interesting study to be aware of in relation to Pulmonary Artery Catheter's hemodynamic monitoring) 

Diastolic Pulmonary Vascular Pressure Gradient: A Predictor of Prognosis in “Out-of-Proportion” Pulmonary Hypertension (1)

Background: Left-sided heart disease (LHD) is the most common cause of pulmonary hypertension (PH). In patients with LHD, elevated left atrial pressure causes a passive increase in pulmonary vascular pressure by hydrostatic transmission. In some patients, an active component caused by pulmonary arterial vasoconstriction and/or vascular remodeling superimposed on left-sided pressure elevation is observed. This “reactive” or “out-of-proportion” PH, defined as PH due to LHD with a transpulmonary gradient (TPG) > 12 mm Hg, confers a worse prognosis. However, TPG is sensitive to changes in cardiac output and left atrial pressure. Therefore, we tested the prognostic value of diastolic pulmonary vascular pressure gradient (DPG) (ie, the difference between invasive diastolic pulmonary artery pressure and mean pulmonary capillary wedge pressure) to better prognosticate death in “out-of-proportion” PH.

Methods: A large database of consecutive cases was analyzed. One thousand ninety-four of 2,351 complete data sets were from patients with PH due to LHD. For proof of concept, available lung histologies were reviewed.

Results: In patients with postcapillary PH and a TPG > 12 mm Hg, a worse median survival (78 months) was associated with a DPG ≥ 7 mm Hg compared with a DPG < 7 mm Hg (101 months, P = .010). Elevated DPG was associated with more advanced pulmonary vascular remodeling.

Conclusions: DPG identifies patients with “out-of-proportion” PH who have significant pulmonary vascular disease and increased mortality. We propose a diagnostic algorithm, using pulmonary capillary wedge pressure, TPG, and DPG in sequence to diagnose pulmonary vascular disease superimposed on left-sided pressure elevation.

References and further reading:

1. Christian Gerges; Mario Gerges, MD; Marie B. Lang; Yuhui Zhang, MD; Johannes Jakowitsch, PhD; Peter Probst, MD; Gerald Maurer, MD; Irene M. Lang, MD - Diastolic Pulmonary Vascular Pressure Gradient: A Predictor of Prognosis in “Out-of-Proportion” Pulmonary Hypertension  Chest. 2013;143(3):758-766. doi:10.1378/chest.12-1653 

2. Pulmonary hypertension in sepsis: Measurement by the pulmonary arterial Diastolic-pulmonary wedge pressure gradient and the influence of passive and active factors. Chest 1978; 73:583-91 

3. Significance of the pulmonary artery diastolic-pulmonary wedge pressure gradient in sepsis. Crit Care Med 1982; 10:658-61 

4. Pulmonary artery diastolic and wedge pressure relationships in critically and injured patients. Arch Surg 1988; 123:933-6 

5. Increased Pulmonary Venous Resistance Contributes to Increased Pulmonary Artery Diastolic-Pulmonary Wedge Pressure Gradient in Acute Respiratory Distress Syndrome - Anesthesiology: Volume 102(3) March 2005 pp 574-580

Saturday, December 17, 2016

Q: The goal of optimum PEEP is to?

A) avoid derecruitment
B) optimize best oxygenation at lowest FiO2
C) best balance between acceptable hypoxemia and permissive hypercapnia
D) minimize Dead space to zero
E) get best compliance  

Answer: A (1)

Optimum PEEP continue to remain a concept of debate among critical care practitioners. To make things complicate optimum PEEP is a not a static component, rather is a constantly changing physiological model depending on the relationship between lung volume, respiratory mechanics, dead space, cardiac output, compliance, shunt and oxygenation. But at the end the primary goal is to avoid de-recruitment. This is a misconception that optimum PEEP is to obtain best oxygenation at lowest FiO2, or playing subjectively with acceptable hypoxemia or permissive hypercapnia. It is impossible to decrease dead space to zero. Arguably, closet choice is the E,  where the best compliance is obtained but compliance can be deceiving depending on number of recruited and decruited alveoli (2) (3).


1.  Caironi P, Cressoni M, Chiumello D, Ranieri M, Quintel M, Russo SG, et al. Lung opening and closing during ventilation of acute respiratory distress syndrome. Am J Respir Crit Care Med. 2009;181:578–86.

2. Suter PM, Fairley HB, Isenberg MD. Effect of tidal volume and positive end-expiratory pressure on compliance during mechanical ventilation. Chest. 1978;73:158–62. 

3. Jonson B, Richard JC, Straus C, Mancebo J, Lemaire F, Brochard L. Pressure-volume curves and compliance in acute lung injury: Evidence of recruitment above the lower inflection point. Am J Respir Crit Care Med. 1999;159:1172–8. 

Friday, December 16, 2016

Q: What is Carnett's sign?

Answer: Carnett's sign is an easy to do bedside exam in 5 seconds. It may provide significant clinical clues. This maneuver is performed in patients with acute abdominal pain to differentiate between intraabdominal pathology (like appendicitis) or abdominal wall pathology (like rectus sheath hematoma or hernia).

During the exam, the patient is asked to lift the head and shoulders from the supine position or to raise both legs with straight knees - to tense the abdominal muscles. If pain increase in intensity, the abdominal wall is the likely source of pain and if the abdominal pain decreases, an intra-abdominal pathology of the pain is likely


Gray DW, Dixon JM, Seabrook G, Collin J (July 1988). "Is abdominal wall tenderness a useful sign in the diagnosis of non-specific abdominal pain?". Ann R Coll Surg Engl. 70 (4): 233–4