Monday, February 28, 2011

Q: Beside Erectile Dysfunction and Pulmonary Hypertension , Sildenafil (Viagra) can be use for treatment in which other disease processes?

Answer: Altitude sickness and Jet lag recovery

Sildenafil has shown to be effective in prevention and treatment of high-altitude pulmonary edema mostly suffered by mountain climbers 1,2. Also some research papers shows that it may help in recovering Jet lag time 3.


1. Richalet JP, Gratadour P, Robach P, et al. (2005). "Sildenafil inhibits altitude-induced hypoxemia and pulmonary hypertension". Am. J. Respir. Crit. Care Med. 171 (3): 275–81.

2. Perimenis P (2005). "Sildenafil for the treatment of altitude-induced hypoxaemia". Expert Opin Pharmacother 6 (5): 835–7.

3. Agostino, P. V.; Agostino PV, Plano SA, Golombek DA (2007). "Sildenafil accelerates reentrainment of circadian rhythms after advancing light schedules". Proc. Natl. Acad. Sci. U.S.A. 104 (23): 9834–9.

Sunday, February 27, 2011

Inhaled Milrinone?

Background: Inhaled administration of milrinone reduces pulmonary artery pressure. Pulmonary hypertension (PH) and right heart failure are associated with difficult separation from cardiopulmonary bypass (CPB). Therefore, inhaled milrinone could facilitate separation from CPB.

Objective: To determine the impact and timing of administration of inhaled milrinone.

Methods: A retrospective analysis of our experience on high-risk patients receiving inhaled milrinone was conducted to evaluate the postoperative course after administration of the drug.

Results: Seventy-three patients received inhaled milrinone from June 2002 to February 2005. Mean age was 64 ± 13 years, with a mean preoperative Parsonnet score of 27 ± 14. Inhaled milrinone (5 mg) was administered before (n = 30) or after (n = 40) CPB, three patients had off-pump procedures and were excluded. CPB time was 145 ± 78 min with cross-clamping times of 91 ± 56 min without any significant difference between groups. Fifty-four patients (74%) had difficult separation from CPB, 14 patients (19%) required an intra-aortic balloon pump and 10 patients (14%) needed emergency reinitiation of CPB for hemodynamic instability. Ten patients died in the perioperative period (13.7%). Patients receiving inhaled milrinone prior to CPB initiation had a lowering pulmonary artery pressure after CPB (p less than .01) and had less emergency reinitiation of CPB after weaning (3% vs 23%, p = .02) as compared to those with administration after CPB. No detectable side effects were directly linked to the administration of the drug.

Conclusion: In this high-risk cohort, use of inhaled milrinone was well tolerated. Administration before initiation of CP coul help weaning from CPB.

References: click to get abstract/article

Preliminary experience with inhaled milrinone in cardiac surgery - Eur J Cardiothorac Surg 2007;31:1081-1087.

2. Inhaled Milrinone: A New Alternative in Cardiac Surgery? - SEMIN CARDIOTHORAC VASC ANESTH December 2006 vol. 10 no. 4 346-360

3. Milrinone Inhaled in Cardiac Surgery -

Saturday, February 26, 2011

Q; Is Digoxin a diuretic?

A: Yes it has direct diuretic property! Digoxin increases diuresis by at least 4 mechanisms

  • Direct vasodilation
  • Increased CO improves renal hemodynamics
  • Inhibition of tubular reabsorption of sodium, of renal Na+ -K+-ATPase, and of concentrating and diluting ability
  • Increased secretion of atrial natriuretic peptide


1. Rahimtoola SH, Tak T. The use of digitalis in heart failure. Curr Probl Cardiol. 1996; 21: 781–756

Friday, February 25, 2011

Q; What is the five (5) "P" Philosophy before doing any Critical Care procedure?

Proper Preparation Prevents Poor Performance.

Thursday, February 24, 2011

Q: Digitalis even with therapeutic serum levels causes chromatopsia and photopsia. What is that?


Chromatopsia = a subjective perception that objects possess colors other than their objective colors, especially that of the yellow or green variety.

Photopsia = the subjective sensation of seeing lights not present in the environment.

Visual abnormalities are the most common subjective symptoms of digitalis intoxication. "Digitalized"patients may also note other less visual symptoms like snowy vision, blurred vision and decreased visual acuity. It is important to note that visual disturbances may be the sole clinical manifestation of digitalis intoxication - and more importantly may happen even within or below the therapeutic range and without any other clinical evidence of digitalis toxicity.

Wednesday, February 23, 2011

Q: Describe direct effect of Lasix on brain?

Answer: Lasix reduces ICP by decreasing the production of CSF. It interfers with the Na transport and in turn slows the production of CSF fluid from the choroid plexi. Another cardiovascular drug which has similar effect is Digoxin.

Tuesday, February 22, 2011

Q: What is "Z Syndrome"?

Answer: "Z Syndrome" is a metabolic syndrome (“syndrome X”), associated with sleep disturbances. It is a cluster of 5 components.

  • insulin resistance,
  • obesity,
  • hypertension,
  • dyslipidemia, and
  • Obstructive sleep apnea (OSA)

Clinical Significance: Treating OSA eliminates recurrent episodes of hypoxaemia and the haemodynamic and respiratory stresses. In ICU these patients may benefit from application of nocturnal CPAP mask.

Monday, February 21, 2011

Q: 14 year old male teenager is admitted to ICU with fever, vomitting and confusion. On examination you noticed rash on palms and feet. Patient has no past medical history except recent viral infection for which he took Aspirin as well as Tylenol (acetaminophen). You are suspecting Reye's Syndrome. Which one could be responsible for it?

A) Aspirin
B) Tylenol
C) Both

Answer: Both

Though Aspirin is well described to cause Reye's Syndrome but similarly Tylenol has been described in studies to cause Reye's Syndrome as well, when taken in viral infection. Though its almost exclusively happens in children but adult cases has been reported too.

Sunday, February 20, 2011

Q: 52 year old female with previous history of CVA is now brought to ICU with probable diagnosis of thyroid storm. Which one medicine you should look for and stop it till patient get stablizes?

Answer: Aspirin

Aspirin is an universal medicine on most patient's medication list particularly in patients with stroke, cardiac or vascular history. Aspirin should be held and avoided in thyroid storm to prevent decreased protein binding and subsequent increases in free T3 and T4 levels. Infact Aspirin itself is known to precipitate thyroid storm

Saturday, February 19, 2011

Q: Which one lab work can quickly differentiate between thyrotoxic periodic paralysis and spontaneous periodic paralysis?

Answer: Phosphate level

In spontaneous periodic paralysis phosphorus levels are likely to be normal and thyrotoxic periodic paralysis is most likely to have hypophosphatemia.

Friday, February 18, 2011

Q: What is the ratio of Potassium and Phosphate - when you prescribe Potassium-Phosphate to Patient?

Answer: 10 meq : 7.5 mmol

To be precise, 1 mmol of intravenous phophate delivers 1.46 meq of potassium in "K-phos rider". To make it in round figure, 7.5 mmol of phosphate gets deliver with 10 meq of potassium.

Thursday, February 17, 2011

Is anti-platelet also protective for Acute Lung Injury (ALI)?

In one of the recent study published recently in 'Chest', it showed that people with prehospitalization Antiplatelet Therapy have a reduced incidence of ALI/ARDS!

Platelet activation is a key component of ALI pathophysiology so investigators examined the association of prehospitalization antiplatelet therapy with development of ALI in critically ill patients. A total of 161 patients were evaluated. Seventy-nine (49%) were receiving antiplatelet therapy at hospital admission; 33 (21%) developed ALI/ARDS. Antiplatelet therapy was associated with a reduced incidence of ALI/ARDS (12.7% vs 28.0%; OR, 0.37; 95% CI, 0.16-0.84; P = .02). This association remained significant after adjusting for confounding variables.

Prehospitalization Antiplatelet Therapy Is Associated With a Reduced Incidence of Acute Lung Injury, A Population-Based Cohort Study - CHEST February 2011 vol. 139 no. 2 289-295 (

Wednesday, February 16, 2011

Q: It is a norm to do electrolytes frequently in ICUs. One of the essential electrolyte is calcium. Do you know what level of ionized calcium - High or Low - may relate to ICU mortality?

Answer: In one of the recent study 177,578 ionized calcium measurements were performed, from 7024 patients, with a mean value of 1.11 mmol/L (ionized calcium measured every 4.5 hrs on average).

From multivariate logistic regression analysis, an ionized calcium less than 0.8 mmol/L or an ionized calcium more than 1.4 mmol/L were independently found to be associated with ICU and hospital mortality.

Ionized calcium concentration and outcome in critical illness, Critical Care Medicine: February 2011 - Volume 39 - Issue 2 - pp 314-321

Tuesday, February 15, 2011

Q: 68 year old female is admitted to ICU with fever and mental status change. MRI, LP and lab work up has been done along with medical treatment including seizure prophylaxis. Diagnosis of viral encephelitis is made. 3 days post admission, patient is now hemodynamically stable and neurologically improved but since admission continue to have hyponatremia despite treatment with normal saline. What could be your concern?

Answer: Syndrome of inappropriate secretion of antidiuretic hormone (SIADH)

SIADH is common in encephelitis and should raise concern with persistent hyponatremia. SIADH is probably caused by disturbance of the hormonal control at the hypothalamus on the pituitary gland due to the spreading of inflammation to these areas.

Monday, February 14, 2011

Q: Which route is least preferable for putting central dialysis catheter in a patient presented with acute renal failure? - Choose one
A) Internal Jugular

B) Subclavian

C) Femoral

D) Axillary

E) Transhepatic


The internal jugular vein is the most preferred site due to its easy puncture and the low rate of complications. The subclavian route should be avoided if possible, since it results in high stenosis and thrombosis rates, which subsequently prevent the use of the upper extremity for the creation of A-V fistulas if needed. The femoral is another good choice for temporary measure with easy access but has disadvantage of a high thrombosis and infection rates.The axillary vein placement requires an experienced operator. Transhepatic is technically difficult and reserve for advance cases.

Sunday, February 13, 2011

Saturday, February 12, 2011

Q: 54 year old patient with CHF presented to ER with dizzyness. Patient is found to be in 3rd degree AV block. Digoxin level is 4.2 nmol/l. You decide to adminster Digibind. 12 hours later nurse call you with potassium level of 2.8 mEq/L?

Answer: With administration of DigiFab (Digibind), serum potassium concentration should be followed very closely. Digibind shifts potassium back into the cell and life threatening hypokalemia may develop rapidly.

Actually, Digoxin causes a shift of potassium from inside to outside of the cell, may causing a life-threatening hyperkalemia despite whole body deficit of potassium. With administration of Digifab, actual hypokalemia may manifest which could be equally life threatening.

Friday, February 11, 2011

Q: Beside patients with renal failure - which patients should not be exposed to MRI contrast agents to avoid Nephrogenic Systemic Fibrosis?

Answer: Life threatening condition called nephrogenic systemic fibrosis is an irreversible skin disease that can develop in those with kidney impairments who have been exposed to MRI contrast agents that contain gadolinium.

CDC (The Center for Disease Control) has warning in patients with a medical history of:

  • moderate to end-stage kidney disease (on or off dialysis)
  • a kidney transplant
  • use of immuno-suppressant medications
  • any condition, such as hepatitis C or lupus, that is known to impair kidney function

Previous related Pearl: Gadolinium based contrast agent (GBCA) and renal insufficiency

Thursday, February 10, 2011

Q: Can patient with pulmonary artery catheter (PAC) have MRI?

Answer: Preferably not.

MRI should not be ideally performed in patients with pulmonary artery catheters. It is recommended for these patients to pulmonary artery catheter be temporarily removed for the MRI. PACs contain an electrical thermister that allow for thermodilution measurements. Any electrical conductor, such as this, in the presence of alternating magnetic fields, generate and electrical current which not only can melt parts of the catheter but may induce arrhythmias

Wednesday, February 9, 2011

Q: What is the equivalency of Fentanyl and Morphine?

Answer: 100 micrograms of fentanyl is approx. equal to 10 mg of morphine.

Tuesday, February 8, 2011

Now you have IV Tylenol

U.S. Food and Drug Administration (FDA) has granted marketing approval for IV version of acetaminophen (OFIRMEV) about 3 months ago and will be marketed this year. OFIRMEV is indicated for the management of mild to moderate pain, the management of moderate to severe pain with adjunctive opioid analgesics, and the reduction of fever, particularly for postoperative pain.

In clinical studies, OFIRMEV improved pain relief, reduced opioid consumption, and improved patient satisfaction when used as part of a multi-modal regimen. It can be use in adults as well as pediatric patients.

OFIRMEV standard dose is 1000 mg every six hours or 650 mg every four hours. It has an onset of action within 15 minutes after treatment.

Monday, February 7, 2011

Q: What is the direct effect of Digoxin in brain?

Answer: Digoxin has shown to decrease CSF production in humans significantly, probably by inhibiting Na-K-ATPase pump. It has been described as an alternate or adjuvent treatment in Pseudotumor Cerebri beside carbonic anhydrase inhibitor (eg, acetazolamide).

Sunday, February 6, 2011

Q: Define chylothorax and describe different treatment modalities?

Answer: Chylothorax is defined as triglycerides more than 113 mg/dl (1.24 mmol/L) in pleural cavity.

A number of therapeutic interventions have been used to reduce chyle production and promote resolution of a chylothorax. Initial management typically includes restriction or temporary cessation of enteral feedings. Enteral feedings high in medium-chain triglycerides (MCT), or parenteral nutrition may be used. Total parenteral nutrition typically results in resolution in 75 to 80% of cases by that time. In resistant cases, pleurodesis, ligation of the thoracic duct, or placement of drains and pleuroperitoneal shunts may be considered.

Octreotide has become another option for management of patients with chylothorax. Although the exact mechanism by which the drug exerts its effects has not been defined, it is believed that the multiple effects of octreotide on the gastrointestinal tract and the reduction in splanchnic blood flow reduce thoracic duct flow and decrease the triglyceride content of chyle.

Saturday, February 5, 2011

A note on age factor for vasospasm after SAH

Age factor has always been considered in risks factors for cerebral vasospasm after the subarachnoid hemorrhage. It has been described as more common in younger patients. It is interesting to note that older people enjoy some safety from vasospasm after SAH secondary to the age-related increase in atherosclerosis, which impairs contractility and elasticity of small arteries and arterioles.

But a recent article published in "Neurosurgery" concluded that; "Age does not seem to be a significant predictor for cerebral vasospasm after subarachnoid hemorrhage".

Other risk factors for vasospasm persists which includes larger bleed in the subarachnoid space, female sex and smoking.

Patient Age and Vasospasm After Subarachnoid Hemorrhage - Neurosurgery: October 2010 - Volume 67 - Issue 4 - pp 911-917

Friday, February 4, 2011

Editors' note: Today we will take break from pearls and will publish an email from one of our regular reader. We hope someone can help him in his endeavors.

"I am an associate consultant of ICU in King Saud Medical City, lecturer of anesthesia and ICU in Cairo faculty of medicine.

I have 2 inquiries.

1- I want to go through research in stem cell transplantation in vegetative states that follow traumatic brain injury. I have proposal for this research and I want to know who can help me in this from the technical point of view. Also in ARDS patients, i m preparing same protocol. I am now in KSA, Riyadh. I have my proposal ready to email if needed.

2- I need an updated powerpoint presentation on non-invasive hemodynamic monitoring in ICU.

Thank you,


Thursday, February 3, 2011

Cefepime's neurotoxic effects - underestimated?

Background: Cases of cefepime neurotoxicity have been Sporadically reported in patients with renal failure. The neurotoxicity of cefepime might be underestimated and the frequency of its neurotoxic effects may be insufficiently recognized.

Methods: We retrospectively reviewed the files of patients with renal failure who were treated with cefepime and who developed neurological complications.

Results: All 8 patients developed decreased conscience, confusion, agitation, global aphasia, myoclonus, chorea-athetosis, convulsions and coma. The latency, the period between the start of treatment and neurologicaldeterioration, was 4,75 ± 2,55 days (range: 1–10 days). All patients died 17 ± 14,7 days (range: 1–42 days) after becoming symptomatic. Three of them died shortly after neurological deterioration. Five patients developed a neurological “tableau” with global aphasia. Three patients showed clinical improvement after the discontinuation of cefepime. Electroencephalography revealed diffuse slow-wave activity (delta) and triphasic sharp wave activity. These findings confirm the possible neurotoxicity of treatment with cefepime in patients with renal failure. In none of the deceased patients have we been able to directly demonstrate a causal relationship between neurotoxicity and mortality. However, when a patient treated with cefepime develops neurological deterioration or aphasia, one must be aware of cefepime's potential neurotoxicity and treatment should be stopped.

Conclusion: We recommend that, in view of the high and unexplained mortality, the use of cefepime in patients with Kidney failure should be carefully considered.

The neurotoxicity and safety of treatment with cefepime in patients with renal failure - Nephrology Dialysis Transplantation, Volume23, Issue3 Pp. 966-970.

Wednesday, February 2, 2011

Q: Propofol should be given with caution in which common allergy?

A: Egg allergy

Originally propofol was launched 32 years ago but was withdrawn from the market due to reports of anaphylactic reactions. It was re-launched in 1986 by AstraZeneca with the brand name Diprivan with preparation containing 10% soybean oil and 1.2% purified egg lecithin, a phosphatidylcholine found in egg yolk.

A history of egg allergy does not necessarily contraindicate the use of propofol. Most egg allergies are related to a reaction to the egg white (albumin) and not to the egg yolk (lecithin). This could explain why 'propofol' is only very rarely a problem. However, a patient who has an egg allergy should be carefully questioned.

Tuesday, February 1, 2011

Q; What is 'Buffalo chest’?

Answer: An interpleural communication results in a single pleural space within a chest (or communicating pneumothoraces on both sides of chest) is called "Buffalo chest'.

Background: Each lung is enveloped in a pleural sac. The pleural sac consists of two serous membranes: the parietal pleura, which lines the thoracic wall, mediastinum and diaphragm; and the visceral pleura, which invests the lung. A potential space called the pleural cavity exists between the parietal and visceral pleura. A pneumothorax occurs when air fills this cavity. The two pleural sacs are separate structures therefore, a pneumothorax is unilateral, unless a communication exists between each pleural cavity.

A communication between each hemithorax can be congenital, iatrogenic or traumatic. It has been reported after procedures involving median sternotomy, laparoscopic surgery and heart and lung transplants. In surgical cases, the communication results from the disruption of the anterior pleural reflections.

An interpleural communication results in a single pleural space. This is termed ‘Buffalo chest’ because North American buffalo, or bison, lack an anatomical separation between the two hemithoraces. This facilitated death by bilateral tension pneumothoraces from a hunter's single arrow to the chest.

There should be a complete resolution of the ipsilateral and contralateral pneumothoraces via the single chest drain.