Sunday, May 31, 2009

Sunday May 31, 2009

Give atleast one advantage and disadvantage of Chlorhexidine as an antiseptic?

Answer: Chlorhexidine has good residual activity with more than 6 hours once applied. But it has very poor activity against gram-negative bacilli and fungi. Chlohexidine is recommended as an antiseptic before any procedure due to presence of gram-positive (staph. Epidermis) on skin (90%).

Inversely, Betadine (iodophors) has more broader coverage but has inconsistent residual activity. In case if Betadine is used for procedure, it should stays in skin contact for atleast 2/3 minutes - as Iodine inside the complex need some time to get release from the carrier molecule (polyvinylpyrrolidone) to act. Slow release of iodine from carrier molecule is a desired effect as it prolongs the action as well as decrease irritation of skin.
(Reason to bring this point is to discourage the practice of wipe betadine after finishing procedure. Residents have been seen to wipe off site after procedure with Saline or ETOH to make procedure look 'clean' but this decreases the antimicrobial effect of Betadine).

Friday, May 29, 2009

Friday May 29, 2009 (pediatric pearl)
What is the risk of excepient toxicity in critically ill children?

Background: Excipients like benzyl alcohol (BA), a preservative, and propylene glycol (PG), the therapeutically inactive components of pharmaceutical products, are increasingly being used in medications routinely administered to critically ill neonates. Generally regarded as inert, prolonged, or large exposures to excipients can be harmful especially of concern in critically ill neonates given their limited metabolic capacity, and the frequency with which they are exposed to medications formulated with BA and PG.

Clinical Presentation: In neonates, BA toxicity has been strongly associated with metabolic acidosis, seizures, and gasping respirations, and PG toxicity has resulted in serum hyperosmolality, seizures, and respiratory arrest. PG and BA are osmotically active and produce a concentration-dependent increase in serum osmolality. For this reason, monitoring of the osmolal gap has been suggested as a means of assessing potential accumulation in patients receiving PG-containing medications at high doses or by continuous infusion.

In a retrospective study the mdian (range) cumulative dose was 4.5 mg/kg/day (0.6–319.5 mg/kg/day) for BA, and 204.9 mg/kg/day (17.3–9472.7 mg/kg/day) for PG. Patients who received medications via continuous infusion received significantly higher excipient doses than patients who received medications intermittently. In this subset of patients, median cumulative excipient doses (BA, 106.3 mg/kg/day and PG, 4554.5 mg/kg/day) were approximately 21 and 180 times the acceptable daily intakes of BA and PG (5 and 25 mg/kg/day), respectively, and exceeded the doses above which toxicity has been reported in infants. Midazolam and lorazepam were involved in over two-thirds of BA and PG exposures, respectively.

Conclusions: Critically ill neonates, especially those receiving medications by continuous infusion, are at risk of being exposed to BA and PG at potentially toxic doses during routine medication administration. Given the serious adverse reactions known to be associated with BA and PG, future studies are warranted to determine the clinical consequences associated with this degree of excipient exposure.

Both BA and PG partially undergo oxidative metabolism in the liver to benzoic acid and lactic acid by-products, respectively. A reduced metabolic capacity to inactivate benzoic acid to hippuric acid in newborns, especially preterm infants, has been suggested as the underlying mechanism of BA toxicity. PG undergoes dose and concentration-dependant clearance and may accumulate, along with is metabolites, in the presence of limited hepatic and renal elimination capacity. The half-life of PG has been reported to be 10–31 hours in neonates compared with 2–5 hours in adults.

Reference: click to get reference

Exposure to the pharmaceutical excipients benzyl alcohol and propylene glycol among critically ill neonates. - Pediatric Critical Care Medicine. 10(2):256-259, March 2009.

Thursday, May 28, 2009

Thursday May 28, 2009
Intravenous Lipid Emulsion for treatment of Overdose

Intravenous lipid emulsions, specifically Intralipid®, have been shown to be efficacious in treating overdose from local anaesthetics in animal models. The proposed mechanism of action is through a “lipid sink”. Due to the hydrophobic properties of local anaesthetics, the agents have greater affinity to the lipid properties and are drawn out of the plasma by mass action. This results in an increase in myocardial energy resulting in a greater susceptibility to resuscitation.

In addition to local anaesthetics, lipid emulsions may be used as treatment in the over dose of other agents such as propranolol, verapamil, bupropion, lamotrigine, and clomipramine.

Adverse effects include infection, thrombophebitis, dyspnea, cyanosis, injection site reaction, and hepatobiliary dysfunction.

The dosing regimens vary depending on the source.

Option 1: 20% lipid emulsion, single bolus dose 100mL or 8-16mL/kg OR Bolus 1-2 mL/kg or 100 mL + Continuous infusion 0.2-0.5 mL/kg/min

Option 2: (based on the recommendations by the Association of Anesthetists of Great Britain and Ireland): Lipid emulsion 20% 1.5 mL/kg bolus over 1 minute + Continuous infusion 0.25 mL/kg/min. Repeat bolus every 5 minutes x2 if no return of spontaneous circulation. Increase rate to 0.5 mL/kg/min if no return of spontaneous circulation after 5 or more minutes. Continue infusion until stable and adequate circulation has been restored

Reference: click to get abstract

Rosenblatt MA, Abel M, Fischer GW, Itzkovich CJ, Eisenkraft JB:
Successful use of a 20% lipid emulsion to resuscitate a patient after a presumed bupivacaine-related cardiac arrest. Anesthesiology 2006; 105:217-8

Wednesday, May 27, 2009

Wednesday May 27, 2009
Hyperglycemia: Are we still talking about it

Paper by B Chakrabarti looked at the hyperglycemia as a predictor of outcome during non invasive ventilation in decompensated COPD.

Method: COPD patients presenting with acute hypercapnic respiratory failure at University Hospital Aintree between June 2006 and September 2007 and receiving NIV within 24 hours of admission were prospectively studied. Random blood glucose levels were measured before NIV administration. 88 patients met inclusion criteria

Results: After multi-variate logistic regression, the following predicted outcome:

  • Admission APACHE II score (OR 0.75; 95% CI 0.62-0.90).
  • The combination of baseline RR less than 30 breaths per minute and random glucose less than 7mmol/l (127.27 mg/dl) increased prediction of NIV success to 97% whilst use of all 3 factors was 100% predictive.

  • In acute decompensated ventilatory failure complicating COPD, hyperglycaemia upon presentation was associated with a poor outcome.
  • Baseline respiratory rate and hyperglycaemia are as good at predicting clinical outcomes as the APACHE 2 score.
  • Combining these variables increases predictive accuracy providing a simple method of early risk stratification.

Reference: click to get abstract

Chakrabarti B, Angus RM, Agarwal S, Lane S, Calverley P.
Hyperglycaemia as a predictor of outcome during Non Invasive Ventilation in decompensated COPD. Thorax 18 May 2009. Published online first.

Tuesday, May 26, 2009

Tuesday May 26, 2009

Q; Whats the first and major concern in person who may have clonidine overdose/toxicity?

A: Repiratory depression/Apnea and need of endotracheal intubation.

CNS toxicity in clonidine overdose is similar to that seen in opiates - which is many time missed by caregiver. Central effect of clonidine includes CNS lethargy or coma, miosis and respiratory depression or apnea. Other CNS signs and symptoms include Hypotonia or hyporeflexia, Seizures, Ataxia, dysarthria, Weakness and Hallucinations.

Monday, May 25, 2009

Monday May 25, 2009
A note on Phenytoin use in Digitalis Toxicity

Ventricular tachycardia (V.Tach.) is common in Digitalis toxicity and may respond well to Phenytoin (Dilantin). Lidocaine is another useful choice but phenytoin depress the enhanced ventricular automaticity without significantly slowing AV conduction. Phenytoin may reverse digitalis-induced prolongation of AV nodal conduction. Phenytoin has been shown to dissociate the inotropic and dysrhythmic action of digitalis, thus suppressing digitalis-induced tachydysrhythmias without diminishing the contractile effects. In addition, phenytoin can terminate supraventricular dysrhythmias induced by digitalis, whereas lidocaine may not been as effective.

Phenytoin has been administered in boluses of 100 mg every 5-10 minutes up to a loading dose of 15 mg/kg.

Sunday, May 24, 2009

Sunday May 24, 2009
Picture Diagnosis
44 year old male just returned from Dubai became short of breath at Houston airport

Pulmonary Embolism

Saturday, May 23, 2009

Saturday May 23, 2009
Prophylactic Nasal CPAP Following Cardiac Surgery

Background: Continuous positive airway pressure is a noninvasive respiratory support technique that may prevent pulmonary complications following cardiac surgery. This study was conducted to determine the efficacy of prophylactic nasal continuous positive airway pressure (nCPAP) compared with standard treatment.
The primary end points: were pulmonary adverse effects defined as hypoxemia (P/F ratio less than <100), pneumonia, and reintubation.
The secondary end point: was the readmission rate to the ICU or intermediate care unit (IMCU).

Methods: 500 patients who were scheduled for elective cardiac surgery. Following extubation either in the operating room (early) or in the ICU (late), patients were allocated to standard treatment (control) including 10 min of intermittent nCPAP at 10 cm H2O every 4 h or prophylactic nCPAP (study) at an airway pressure of 10 cm H2O for at least 6 hour.

  • Prophylactic nCPAP significantly improved arterial oxygenation (Pao2/Fio2) without altering heart rate and mean arterial BP.
  • Pulmonary complications including hypoxemia (defined as Pao2/Fio2 <100),>
  • The readmission rate to the ICU or IMCU was significantly lower in nCPAP-treated patients (7 of 232 patients vs 14 of 236 patients, respectively).

Conclusions: The long-term administration of prophylactic nCPAP following cardiac surgery improved arterial oxygenation, reduced the incidence of pulmonary complications including pneumonia and reintubation rate, and reduced readmission rate to the ICU or IMCU. Thus noninvasive respiratory support with nCPAP is a useful tool to reduce pulmonary morbidity following elective cardiac surgery.

Reference: click for article

Prophylactic Nasal Continuous Positive Airway Pressure Following Cardiac Surgery Protects From Postoperative Pulmonary Complications - CHEST May 2009 vol. 135 no. 5 1252-1259 .

Friday, May 22, 2009

Friday May 22, 2009 (pediatric pearl day)
What is the best inflammatory marker to diagnose nosocomial infection in children undergoing cardio-pulmonary bypass?

Scope of Problem: Neonates and infants who undergo surgery for congenital heart defects are at risk of nosocomial infections. However, these children undergoing cardiac surgery with cardiopulmonary bypass often develop a systemic inflammatory response syndrome with an increase in inflammatory markers which makes the diagnosis of infection in the postbypass patient difficult.

STUDY: In a prospective cohort study the investigators tested the hypothesis that procalcitonin (PCT) is a more reliable marker of infection than C-reactive protein (CRP) or and immature-to-total neutrophil ratio (ITR) in the post-CPB child.

The investigators found that, in a receiver operating characteristic curve analysis, PCT was the most reliable variable for the diagnosis of probable/definite sepsis with area under the curve 0.84 (95% confidence interval, 0.75–0.92) compared with 0.73 (0.62–0.84) for ITR and 0.62 (0.52–0.73) for CRP.

A serum PCT concentration more than 2.2 ng/mL was the best cut-off value for the diagnosis of sepsis, with 84% sensitivity and 72% specificity. This cut-off has a PPV of only 32%, which would mean that only about one in three children suspected and hence treated for sepsis would actually have true sepsis. The NPV is 97%, which would mean that 3 in 100 would potentially not be treated when they really did have sepsis. The best cut-off depends on the day after bypass. An increase in the marker is more likely to suggest infection than a single value, particularly in the first days postbypass.

Conclusions: CRP was a poor marker of sepsis in this study. Children with a PCT less than 2.2 ng/mL or ITR less than 0.08 were unlikely to have definite or probable sepsis. However, only a third of children with high values of PCT and ITR had definite or probable sepsis.

Reference: click for reference

Procalcitonin versus C-reactive protein and immature-to-total neutrophil ratio as markers of infection after cardiopulmonary bypass in children. - Pediatric Critical Care Medicine. 10(2):217-221, March 2009.

Thursday, May 21, 2009

Thursday May 21, 2009

What is the ratio of alpha and beta blockade in Labetalol?

A: As an anti-hypertensive, Labetalol has both alpha-blockade and beta-blockade activity. The ratio of alpha to beta blockade activity is

1:3 when used orally
1:7 when used intravenously

Wednesday, May 20, 2009

Wednesday May 20, 2009
Pulmonary Embolism Severity Index (PESI)

Study by Aujesky helps us to predict the 30 day mortality risk in patients with PE. Below are the two tables which gives the risk severity, and second table helps to give the assigned points on the basis of risk factors.

Category = Points = Risk category
1 = less than or equal to 65 = Very Low
2 = 66-85 = Low
3 = 86-105 = Intermediate
4 = 106-125 = High
5 = more than 125 = Very High

Predictors and Assigned Points

Age/year = Age in years
Male Sex = +10
Hx Cancer = +30
Heart Failure = +10
Chronic lung disease = +10
Pulse more than 110/min = +20
SBP less than100 mm hg = +30
Resp Rate more than 30/min = +20
Temp less than 36ÂșC = +20
Altered mental status = +60
O2 Sat less than 90% = +20

References; click for reference

1. Aujesky D, Perrier A, Roy PM, Et al.
Validation of a clinical prognostic model to identify low risk patients with pulmonary embolism. J Intern Med 2007; 261(6): 597-604

Aujesky D, Obrosky D, Stone RA, et al.
Derivation and validation of a prognostic model for pulmonary embolism. Am J Respir Crit Care Med 2005; 172(6): 655-6

Tuesday, May 19, 2009

Tuesday May 19, 2009
Geneva Risk Score: Predicting adverse outcome in patients with acute PE (Pulmonary Embolism)

Study by Wicki helps us to predict adverse outcome in patients with acute PE. Score of less then or equal to 2 suggest low risk, whereas score of three or greater then three suggest high risk of adverse outcome in patients with PE

Risk Factors with Points

Cancer = 2 points
CHF = 1 points
Previous DVT = 1 Points
SBP less than 100 mm hg on admission = 2 points
Arterial PaO2 less than 8kPa on admission = 1 point
Presence of DVT on Ultrasound = 1 point

References: click to get abstract

Wicki J, Perrier A, Perneger TV, et al.
Predicting adverse outcome in patients with acute pulmonary embolism: a risk score. Thromb Haemost 2000; 84(4): 548-552

Monday, May 18, 2009

Monday May 18, 2009
Probiotics for the prevention/treatment of Antibiotic Associated Diarrhea (AAD) and Clostridium difficile-Associated Diarrhea (CDAD)?

Probiotics are defined as live organisms (bacteria, yeast) that provide beneficial effects to the health of a host when ingested. The effects of probiotics vary depending on the type/strain (e.g. S. boulardii, Lactobacillus, Bifidobacterium bifidum), dose, route, and frequency of delivery. Mechanisms of action include elaborating antibacterial molecules e.g. bacteriocins to inhibit the growth and virulence of enteric bacterial pathogens; enhance the mucosal barrier to prevent the binding of enteric pathogens; by promoting an adaptive immune response; and activating receptors in the enteric nervous system, thus promoting pain relief.

C. difficile diarrhea often presents during or after a short course of antibiotic therapy. Offending antibiotics include fluoroquinolones, beta-lactam, betalactamase, amoxicillin, and clindamycin. The current literature has shown promise and potential benefit in the use of probiotics, specifically S. boulardii and Lactobacillus, as a means to restore GI flora and prevent/treat AAD. However, the data lacks statistical power and poor study design.

Recommendation: Probiotics should not be routinely used for the prevention/treatment of AAD and CDAD until further studies are performed.

References: click to get abstract

1. Sherman PM, etal.
Unraveling Mechanisms of Action of Probiotics - Nutr Clin Pract 2009; 24(1):10-14.

2. Imhoff A, etal. -
Is There a Future for Probiotics in Preventing Clostridium difficile–Associated Disease and Treatment of Recurrent Episodes? - Nutr Clin Pract, February 1, 2009; 24(1): 15 - 32.

3. C. L. Rohde, V. Bartolini, and N. Jones -
The Use of Probiotics in the Prevention and Treatment of Antibiotic-Associated Diarrhea With Special Interest in Clostridium difficile-Associated Diarrhea - Nutr Clin Pract, February 1, 2009; 24(1): 33 - 40.

Sunday, May 17, 2009

Sunday May 17, 2009
Cardaic enzymes with and without perfusion

Saturday, May 16, 2009

Saturday May 16, 2009

Insertion Of Laryngeal Mask Airway

Friday, May 15, 2009

Friday May 15, 2009 (pediatric pearl)
Weaning and Extubation in Children: Some Facts

Over 50% of ventilated PICU patients will have been extubated by 48 hrs after admission, but the rest often require prolonged ventilatory support. Failed planned extubations in the latter group average 8.0% but range up to 20% in some studies. Conversely, 50% of unplanned extubations end in success, implying that some patients could be extubated earlier.

Not all patients require gradual weaning. Both adult and pediatric studies have shown that when patients pass a SBT and are subjected to an ERT, 50%–75% of the patients are deemed ready to extubate.

* There are no infallible predictive tests for successful extubation. The RSBI has become moderately popular but since there is a wide range of age groups with different respiratory rates it may not be a good predictor of extubation success or failure in the pediatric population. Whether age-specific f/VT ratio is better is currently unknown.

* Adult studies show that T-piece or PS trials for an ERT are equally effective; IMV or SIMV are not deemed as useful. Pediatric studies have led to similar conclusions.

* Use of a weaning protocol results in faster weaning in adults. Although the data are less clear in children, it is likely a consistent approach to ventilator weaning will shorten ventilator time and result in better outcomes.

* A recent Cochrane Review on the role of steroids concludes : “Using corticosteroids to prevent (or treat) stridor after extubation has not proven effective for neonates, children or adults. However, given the consistent trend toward benefit, this intervention does merit further study”

Reference: click to get abstract

Weaning and extubation readiness in pediatric patients - Pediatric Critical Care Medicine. 10(1):1-11, January 2009

Thursday, May 14, 2009

Thursday May 14, 2009

Scenario: 39 year old male developed 10% right sided pneumothorax with no major clinical signs after subclavian central line placement. Conservative observation with application of NR-mask didn't resolve the pneumothorax but actually now size has increased to 30%. You inserted chest tube with resolution of pneumothorax and proper chest tube placement as documented by immediate CXR at bedside. 10 minutes later patient went into shortness of breath. On clinical exam, bilateral breath sounds are audible but with rales more pronounced on right side. While waiting for repeat CXR, your probable diagnosis?

Answer: Re-expansion pulmonary edema (REPE)

REPE is a rare complication occurring after the insertion of a chest tube for pneumothorax or pleural effusion. REPE can occur on the ipsi- or contralateral side, can be bilateral and can even be asymptomatic.

The exact pathophysiology for this complication is unknown. Oxygen radicals are produced during the hypoxemia in the collapsed lung. Moreover, the activity of different cytokines have been implicated in the pathogenesis of REPE.

Major risk factors associated with REPE:

  • younger age ( less than40 years),
  • longer duration of lung collapse ( more than4 days),
  • large pneumothorax ( more than 30% of a single lung)

Reference: click to get article

Ipsilateral reexpansion pulmonary edema after drainage of a spontaneous pneumothorax: a case report - J Med Case Reports. 2007; 1: 107. Published online 2007 September 29

Wednesday, May 13, 2009

Wednesday May 13, 2009

Extrapontine myelinolysis from severe hyponatremia

(a) Normal MRI scan taken five months before the episode of severe hyponatremia, when serum sodium was 140 mmol/l.

(b) Ten days after the episode of severe hyponatremia, MRI scan showed bilateral high-intensity abnormalities in the lenticular nuclei and in the head of the caudate nucleus (arrows).

(c) At day 32, the lesions shown in panel b appear more pronounced (arrows).

(d) At day 32 with fluid-attenuation inversion recovery, high intensity lesions were also observed in the precentral gyrus (arrows).

Reference: Click to get article

Severe hyponatremia followed by extrapontine myelinolysis - Kidney International (2006) 69, 423.

Tuesday, May 12, 2009

Tuesday May 12, 2009
Does C-reactive protein Helps in ARDS

Study by Bajwa helped to sort the issue out. They measured C- reactive protein levels in 177 patients within 48 hours of disease onset, and measured 60 day mortality, 28 day daily organ dysfunction, and number of ventilator free days.


  • C- reactive protein was significantly lower in non-survivors (p=0.02).
  • Mortality rate decreased with increase in C-reactive protein deciles (p=0.02)
  • Increasing C-reactive protein was associated with increase in 60 days mortality.
  • Patient with high C-reactive protein had significantly lower organ dysfunction score (p=0.001) and more ventilator free days (p=0.02).

Conclusion: Increased C-reactive protein is good.

Reference: Bajwa EK, Khan AK, Januzzi JL, Gong MN et al. Plasma C-reactive protein levels are associated with improved outcome in ARDS. Chest May 2009 published online before print

Monday, May 11, 2009

Monday May 11, 2009
Ventricular Assist Device in the ICU

“Mechanical circulatory support aims to preserve life, restore, circulation provide optimal blood supply to metabolizing tissues, normalize organ function, and allow the heart to recover from an acute insult, and acute decompensation, or a progressive decline of a chronic disorder, without adding further compromise.”

1. Timing of intervention: short term vs. long term: Bridge to recover, to surgery, to transplantation, or to decision

2. Device and patient management: Goal of device implantation is to ensure optimal organ perfusion and ventricular decompression. Total systemic circulation output should exceed 2.2 L/min/m2, SVO2 more than 70%

2a. To achieve this, preload must be optimize

  • Diuresis to prevent third spacing
  • Maintain adequate intravascular volume with fluids, albumin, blood products to correct anemia

2b. Improve/preserve right ventricular function with diuretics,
arrhythmia treatment, avoiding, perioperative myocardial
ischemia, stunning, acidosis, and transfusions

3. Infection: A significant source of morbidity and mortality is infection. Prevent infection by removing indwelling lines and catheters as soon as possible, antibiotic prophylaxis, meticulous sterile techniques and dressing changes, driveline stablilization, early extubation and mobilization, and nutrition support.

4. Anticoagulation: All devices require heparin in the first 24-48 hours post implantation or after cessation of postoperative bleeding. Temporary devices should continue with heparin until decision is made. Long term devices should be converted from heparin to anticoagulant or antiplatelet pending type of device implanted.

Reference: Pitsis AA, et al. Update on ventricular assist device management in the ICU. Curr Opinion in Crit Care. 2008;14:569-578.

Sunday, May 10, 2009

Sunday May 10, 2009

Q: 47 year old male is brought to ER with fever and mental status change. Patient did not produce any urine while foley was inserted. Lab is still pending. A research student made following slide in ER. What is your presumptive diagnosis?


Thrombotic thrombocytopenic purpura (TTP)

TTP is a life-threatening condition which may have a positive outcome if recognized early and medical intervention is initiated early with plasma exchange.

The classic pentad associated with TTP (fever, renal failure, neurological change, thrombocytopenia and microangiopathic hemolytic anemia) are not always easy to recognize. Lab finding of elevated LDH and schistocytosis (arrows in picture above) are very crucial for diagnosis of TTP.

Saturday, May 9, 2009

Saturday May 9, 2009

Q: Which commonly use anti-seizure medicine is not effective or actually has been advise not to use in seizures secondary to Lidocaine?

Answer: Phenytoin (Dilantin)

In seizures secondary to lidocaine, benzodiazepines and barbiturates are the drugs of choice. Phenytoin is not effective.

Friday, May 8, 2009

Friday May 8, 2009 (pediatric pearl day)
Outcome of septic shock in the neonatal period

Septic shock in the neonatal period has a very poor outcome.

Study n = 48

The 28-day mortality was 40%. Adverse outcome at 18 months of corrected age was observed 52% cases (death = 19, severe sequelae = 5). 28% of the infants were alive and had a normal examination at 18 months.

Significant predictors (multivariate analysis) of 28-day mortality and of adverse outcome at 18 months of corrected age were:
  • Weight (kg) at the onset of sepsis
  • Gram-negative infection

Conclusions: Data underscore the extreme vulnerability of very low birth weight infants to septic shock, particularly to Gram-negative species.


Outcome and prognostic factors in neonates with septic shock - Pediatric Critical Care Medicine. 9(2):186-191, March 2008

Thursday, May 7, 2009

Thursday May 7, 2009
Influence of positive end-expiratory pressure (PEEP) on left ventricular regional wall motion in patients with acute respiratory distress syndrome (ARDS)

Regional left ventricular wall motion abnormalities have been described with positive end-expiratory pressure (PEEP). Study was conducted to assess global and regional LV performance in response to PEEP by transoesophageal echocardiography (TOE) in patients with ARDS. Study was conducted on eight critically ill patients with normal systolic LV function requiring mechanical ventilation (tidal volume 6-8 ml/kg, PEEP 12 ± 2 cmH2O) due to ARDS.

Measurements: Regional and global LV performance were assessed at PEEP levels of 5, 10, 15, 20 and 25 cmH2O.

Results: PEEP =15 cmH2O produced a significant reduction in systolic septal wall motion (hypokinesia) and a significant augmentation of lateral systolic wall motion (hyperkinesia). Global LV performance - measured as fractional area change - was not significantly affected.

Reference: Click to get abstract

Influence of positive end-expiratory pressure (PEEP) on left ventricular regional wall motion in patients with acute respiratory distress syndrome (ARDS): from 22nd International Symposium on Intensive Care and Emergency Medicine, Brussels, Belgium. 19–22 March 2002 Critical Care 2002, 6(Suppl 1):P14

Wednesday, May 6, 2009

Wednesday May 6, 2009

Q; EKG below shows characteristics of which electrolyte abnormality?

Answer: Hypokalemia

This EKG shows

  • a long QT interval,
  • ST depression,
  • low T waves, and
  • TU wave fusion

all characteristics of Hypokalemia.

Tuesday, May 5, 2009

Tuesday May 5, 2009

Q; What are 2 types of Atrial flutter?


Type I atrial flutters (tricuspid valve isthmus dependent): Catheter ablation is typically successful and recurrence is less than 5%. Postprocedure anticoagulation with warfarin is usually continued for 4-6 weeks.

Type II atrial flutters (non—tricuspid valve isthmus dependent): These circuits are amenable to catheter ablation but require advanced mapping systems. Recurrence is more common and may also require the use of antiarrhythmic agents for suppression.

Monday, May 4, 2009

Monday May 4, 2009
Transdermal patch burn and MRI

Certain transdermal patches contain aluminum or other metals in the backing of the patches. Patches that contain metal can overheat during an MRI scan and cause skin burns in the immediate area of the patch. Patches usually contain metal in the layer of the patch that is not in contact with the skin (the backing).
Following patches have been identified by FDA.

Catapres TTS
(Lidocaine HCl and epinephrine)
(Nicotine transdermal system)
(Nicotine transdermal system)
Nicotrol TD
(Nicotine transdermal system)
(Testosterone transdermal system)
Salonpas Power Plus
(Methyl Salicylate/Menthol)


1. FDA Public Health Advisory Risk of Burns during MRI Scans from Transdermal Drug Patches with Metallic Backings -

Sunday, May 3, 2009

Sunday May 3, 2009
Drug -Drug interaction / cardiology

Q: Which two commonly use drugs in CHF (congestive heart failure) - may oppose each other's action?

Aspirin and Furosemide (Lasix)

Lasix has a direct vasodilator effect and this effect begins within a few minutes after an administration of IV Lasix. This added effect is very useful in treatment of acute pulmonary congestion. But this desirable action can be blocked by nonsteroidal anti-inflammatory drugs including aspirin.

Mechanism of action is not clear but salicylates may inhibit the renal effects of loop diuretics that are mediated by prostaglandins, including increases in sodium excretion, renal blood flow, and plasma renin activity.

Read interesting commentary on this issue: Aspirin Use in Chronic Heart Failure, What Should We Recommend to the Practitioner? (Barry M. Massie, MD - J Am Coll Cardiol, 2005; 46:963-966


1. Jhund PS, Davie AP, McMurray JJ.
Aspirin inhibits the acute venodilator response to furosemide in patients with chronic heart failure. J Am Coll Cardiol. 2001;37:1234-1238

2. Effect of combined administration of furosemide and aspirin on urinary urate excretion in man - Journal of Molecular Medicine, Volume 57, Number 23 / December, 1979, 1299-1301

Saturday, May 2, 2009

Saturday May 2, 2009

Q: What is the medical term for "cool, clammy, and mottled skin" in cardiogenic shock due to vasoconstriction and subsequent hypoperfusion of the skin?

Answer: Cutis Marmorata

Friday, May 1, 2009

Friday May 1, 2009
Use of Nebulized Lidocaine for Nasogastric Tube Insertion - Pros and cons

A double-blind, placebo-controlled, randomized clinical trial of adult patients was conducted in the EDs of 2 university hospitals. 29 participants were administered nebulized lidocaine (4 mL 10%), and 21 participants received nebulized normal saline solution *. Patient discomfort was measured using a 100-mm visual analog scale. The difficulty of nasogastric tube insertion was evaluated using a 5-point Likert scale.

  • There was a clinical and statistical significant difference in patient discomfort associated with the passage of the nasogastric tube between nebulized lidocaine and placebo groups (mean visual analog scale score 37.7 versus 59.3 mm, respectively).
  • There was not a detectable difference in difficulty with the passage of the nasogastric tube between the 2 groups
  • Epistaxis occurred more frequently in the lidocaine group

Conclusion: Nebulized lidocaine decreases the discomfort of nasogastric tube insertion and should be considered before passing a nasogastric tube. An increased frequency of epistaxis, however, may be associated with its use.

Four milliliters of the trial solution was administered using a face mask and a compressed gas-powered jet nebulizer with an oxygen flow rate of 6 L/min. The patient was instructed to breathe through his or her nose and mouth while the solution was being nebulized. Immediately after the nebulization was completed, the nurse removed the mask and inserted the nasogastric tube with the usual lubrication gel (KY Jelly) in the normal manner.

Reference: Click to get abstract

Nebulized Lidocaine Decreases the Discomfort of Nasogastric Tube Insertion: A Randomized, Double-Blind Trial - [Ann Emerg Med. 2004;44:131-137.]