Monday March 29, 2010


Q: How to calculate Iron Dextran infusion dose in Anemia?

Answer: Intravenous injections of iron dextran are indicated for treatment of patients with documented iron deficiency in whom oral administration is unsatisfactory or impossible.

Dose (mL) = 0.0442 (Desired Hb - Observed Hb) x LBW + (0.26 x LBW)

LBW = Lean body weight in kg.

For males: LBW = 50 kg + 2.3 kg for each inch of patient’s height over 5 feet.

For females: LBW = 45.5 kg + 2.3 kg for each inch of patient’s height over 5 feet.

After administration of iron dextran complex, evidence of a therapeutic response can be seen in a few days as an increase in the reticulocyte count.

Sunday March 28, 2010


Q: Should compression stockings be applied in already diagnosed DVT?

Answer: yes

Compression stockings that provide a 30-40 mm Hg compression gradient should be used, because they are a safe and effective adjunctive treatment that can limit or prevent extension of thrombus. Compression stockings of this type have been proven effective in the prophylaxis of thromboembolism and are also effective in preventing progression of thrombus in patients who already have DVT and PE.

The ubiquitous white stockings known as "Ted hose" produce a maximum compression of 18 mm Hg. Because they provide such limited compression, they have no efficacy in the treatment of DVT and PE, nor have they been proven effective as prophylaxis against a recurrence.


Related previous pearl: inflation and deflation cycle of intermittent pneumatic compression boots

Thursday March 25, 2010
Impact of time to antibiotics on survival in patients with severe sepsis or septic shock

Objective: To study the association between time to antibiotic administration and survival in patients with severe sepsis or septic shock in whom early goal-directed therapy was initiated in the emergency department with 261 patients undergoing early goal-directed therapy.

Results:

• When analyzed for time from triage to appropriate antibiotics, there was a significant association at the less than 1 hr (mortality 19.5 vs. 33.2%; p = .02) time cutoff;
• Similarly, for time from qualification for early goal-directed therapy to appropriate antibiotics, a significant association was seen at the less than/= 1 hr (mortality 25.0 vs. 38.5%; p = .03) time cutoff.
  

Conclusions: Elapsed times from triage and qualification for early goal-directed therapy to administration of appropriate antimicrobials are primary determinants of mortality in patients with severe sepsis and septic shock treated with early goal-directed therapy.



Impact of time to antibiotics on survival in patients with severe sepsis or septic shock in whom early goal-directed therapy was initiated in the emergency department - Critical Care Medicine: April 2010 - Volume 38 - Issue 4 - pp 1045-1053

Tuesday March 23, 2010


Q: Precedex (dexmedetomidine) is stable at room temperature for how long?

Answer: 48 hours

Precedex (dexmedetomidine) is stable at room temperature for 48 hours but preferably total infusion time should not exceed 24 hours.

Dosing:

Bolus: 1mcg/kg over 10 minutes (bolus is drawn up from drip and thus will have same concentration as the infusion: 4mcg/ml).
Infusion Rate: 0.2-0.7mcg/kg/hour

Patients with hepatic failure should require lower doses. Patients with renal failure may also require lower doses.

Click here to have Precedex Protocol

Monday March 22, 2010
Waveform diagnosis





Answer: Mitral Regurgitation

The large V wave in PA waveform signifies severe mitral regurgitation. Hemodynamic tracing in a patient with severe mitral regurgitation. The pulmonary arterial (PA) pressure is severely elevated ( more than 60 mm Hg). In the distal portion of the pulmonary arterial pressure wave, a second peak is seen; this represents the V wave coincident with the ventricular contraction. V waves are usually seen in the pulmonary capillary wedge-pressure waveform.

Sunday March 21, 2010

Fastrach (Intubation via LMA)

Saturday March 20, 2010
Tight Glycemic Control in the ICU - a problem? - A Systematic Review and Metaanalysis

Background: Following publication of the Leuven Intensive Insulin Therapy Trial in 2001, tight glycemic control became the standard of care in ICUs around the world. Recent studies suggest that this approach may be flawed. The goal of this systematic review was to determine the benefits and risks of tight glycemic control in ICU patients and to explain the differences in outcomes among reported trials.

Methods: Prospective, randomized controlled clinical trials (RCTs) that studied the impact of tight glycemic control (blood glucose 80-110 mg/dL) on mortality in ICU patients were identified through a search of MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews, and a citation review of relevant primary and review articles. Data were abstracted on study design, study size, and patient characteristics, as well as on the mean (or median) and SD of the ICU blood glucose level, mean daily dose of insulin administered, average daily caloric intake, percentage of calories given intravenously (parenteral nutrition), incidence of hypoglycemia, need for dialysis, and 28-day/hospital mortality.

Results: We identified seven RCT studies that included 11,425 patients.

1. Overall, tight glycemic control did not reduce

• the 28-day mortality
• the incidence of blood stream infections
• the requirement for renal replacement therapy
  

2. The incidence of hypoglycemia was significantly higher in patients randomized to tight glycemic control.

Metaregression demonstrated a significant relationship between the treatment effect (28-day mortality) and the proportion of calories provided parenterally (P = .005). This suggests that the difference in outcome between the two Leuven Intensive Insulin Therapy Trials and the subsequent trials could be related to the use of parenteral nutrition. When the two Leuven Intensive Insulin Therapy Trials were excluded from the metaanalysis, mortality was lower in the control patients.

Conclusions: There is no evidence to support the use of intensive insulin therapy in general medical-surgical ICU patients who are fed according to current guidelines. Tight glycemic control is associated with a high incidence of hypoglycemia and an increased risk of death in patients not receiving parenteral nutrition.


Toward Understanding Tight Glycemic Control in the ICU- A Systematic Review and Metaanalysis- Paul E. Marik, MD, FCCP and Jean-Charles Preiser, MD - CHEST March 2010 vol. 137 no. 3 544-551

Friday March 19, 2010

Q: Name an epileptic drug which can be given rectally if required?


Answer: Depakote (valproic acid)

Dilute syrup 1:1 with water for use as a retention enema; loading dose: 17-20 mg/kg one time; maintenance: 10-15 mg/kg/dose every 8 hours

Thursday March 18, 2010


Q: Beside diuresis describe 2 more effects of furosemide (Lasix)?


Answer: Lasix is a diuretic which acts on the loop of henle and inhibits reabsorption of both sodium and chloride ions. Beside this basic function of diuresis

1. Lasix also causes peripheral vasodilation (mostly venodilatation) and an increase in systemic venous capacitance. Obviously this helps with the CHF patients.

2. Lasix reduces ICP and can be use in conjunction with Mannitol. By interfering with the Na transport which in turn slows the production of CSF fluid from the choroid plexi.

Wednesday March 17, 2010

Q: What is Atropine test?


Answer: Atropine test is a simple pharmacological test based on the absence of cranial parasympathetic nervous influence on the heart in brain dead patients and may be a useful adjunct to testing brain stem function. A tachycardic response would demonstrate an intact cranial parasympathetic outflow. 2-3 mg of Atropine IV is then given. If there is less than 10 % or no increase in heart rate, this supports the diagnosis of brain death. Additional confirmatory tests are however required.

Tuesday March 16, 2010

Q: Name at least 3 general conditions beside genetic increased plasma cholinesterase activity which may prolong succinylcholine action?


Answer:

1. Metoclopramide (Reglan) - which may prolong succinylcholine action due to effects on pseudocholinesterase.

2. Obesity - may cause resistance to succinylcholine due to more plasma cholinesterase activity.

3. In myasthenia gravis - due to reduced number of nicotinic, neuromuscular junctional receptors which is the target for the drug succinylcholine.

Monday March 15, 2010
Unusual course (sling) of left pulmonary artery

Pulmonary artery sling is a rare condition in which the left pulmonary artery anomalously originates from a normally positioned right pulmonary artery. The left pulmonary artery then progresses posteriorly over the right main bronchus near its origin from the trachea, traverses between the trachea and the esophagus and enters the left hilum. Symptoms include cyanosis, dyspnoea and apnoeic spells. It is almost always fatal and usually requires surgical intervention. Mostly it is diagnosed in childhood and rarely it is asymptomatic and is detected incidentally in asymptomatic adults in whom it can mimic a mediastinal adenopathy.

Sunday March 14, 2010


Q: What is “oxygen saturation gap”?


Answer: The “oxygen saturation gap” is the difference between the calculated oxygen saturation from a standard blood gas machine and the reading from a pulse oximeter. If it is greater than 5%, the patient’s hemoglobin may be abnormal, representing carbon monoxide poisoning, methemoglobinemia, or sulfhemoglobinemia.

Saturday March 13, 2010

Picture Diagnosis

Answer: Pseudomembranous colitis

Above is the endoscopic visualization of pseudomembranous colitis, a characteristic manifestation of full-blown Clostridium difficile colitis. Classic pseudomembranes are visible as raised yellow plaques ranging from 2-10 mm in diameter and scattered over the colorectal mucosa.

Friday March 12, 2010
American Board of Internal Medicine Maintenance of Certification Program

(Poll at NEJM)


"A 55-year-old physician, who graduated from medical school in 1979, completed his internship and junior residency in internal medicine in 1981. He did 3 years of fellowship training in endocrinology, followed by a third year of residency in internal medicine. He then completed and passed the American Board of Internal Medicine (ABIM) qualifying examinations in internal medicine and endocrinology; the ABIM issued to him certificates of unlimited duration, specifying that he held board certification in internal medicine and endocrinology. For the past 24 years, he has been in the practice of general internal medicine with an emphasis on endocrinology. He estimates that about half of his patients see him for endocrine problems exclusively and the remainder see him for issues regarding general internal medicine. He is on the faculty of the medical school from which he graduated, but he spends most of his time caring for patients in an outpatient setting. For 6 months of each year, he has third-year residents, training in internal medicine, shadowing him at his outpatient practice. For one 3-week block each year, he serves as an attending physician on the general medical service of the hospital where he has inpatient privileges, a minor teaching hospital of his medical school at which he trained. During this 3-week period, he has two medical students, two interns, and a senior medical resident under his direct supervision.

He attends the grand rounds lecture series regularly. Once a year, he leaves his practice to attend a weeklong postgraduate course, alternating between internal medicine and general endocrinology. He has never considered enrolling in the maintenance of certification (MOC) program in either internal medicine or endocrinology. His reasoning is that he is up to date in his practice, that he makes frequent use of point-of-care reference services to check on the latest diagnostic or therapeutics practices when he encounters a condition that he does not see frequently, and that the money and time needed to undertake MOC would not be well spent. He has received a communication from the ABIM urging him to undergo the MOC process. He consults you, as a friend and colleague, for advice about what to do.."

Your Vote /Recommendation Click here

(last 1169 people voted with 66% voting against MOC!)

Thursday March 11, 2010


Q: In HFOV (High frequency ventilation) respiratory rate is set as Hertz with usual initial setting of 5-6 Hertz per minute. one Hertz is equal to how many breaths?


Answer: One Hertz is equal to 60 breaths per minute in HFOV

Wednesday March 10, 2010
Oxygen Index

Oxygen index (OI) is one of the objective number to measure the severity of ARDS/lung disease. Recently it has been postulated as cutoff point for initiation of ECMO (extracorporeal membrane oxygenation). There has been a significant resistant in the use of ECMO due to various other non-conventional methods available like high-frequency oscillatory ventilation (HFOV), inhaled nitric oxide (iNO), prone positioning, APRV ventiliation etc. One study 1 showed that OI of 33.2 is a suitable cutoff value for ECMO. Otherwise also it has been said as a better indicator of lung function than P/F ratio

Oxygen Index (OI) = FiO2 x MAP x 100

---------------------
PaO2

* MAP = Mean Airway pressure
FiO2 is in %

1. Oxygenation index for extracorporeal membrane oxygenation: is there predictive significance? - Journal of Artificial Organs, Volume 10, Number 1, March 2007 , pp. 6-9(4)

Tuesday March 9, 2010
Dopamine v. Norepinephrine in Shock

Following pearl is contributed by:

TheAnh Nguyen, PharmD
UT-Austin
ahacorner@yahoo.com


Norepinephrine was as effective and safer than dopamine in a trial of 1,679 patients with shock. Used as first-line vasopressor therapy, the two agents produced these outcomes over the 28 days after randomization.

• There was no significant between-group difference in the rate of death at 28 days (52.5% in the dopamine group and 48.5% in the norepinephrine group, P = 0.10)
• There were more arrhythmic events among the patients treated with dopamine than among those treated with norepinephrine (207 events [24.1%] vs. 102 events [12.4%], P less than 0.001)
• A subgroup analysis showed that dopamine, as compared with norepinephrine, was associated with an increased rate of death at 28 days among the 280 patients with cardiogenic shock but not among the 1,044 patients with septic shock or the 263 with hypovolemic shock (P = 0.03 for cardiogenic shock, P = 0.19 for septic shock, and P = 0.84 for hypovolemic shock, in Kaplan-Meier analyses)

Mar. 4 issue of the New England Journal of Medicine (2010; 362) - link here

Monday March 8, 2010


Question: A standard dose of nebulized albuterol reduces serum potassium by what level?

Answer: A standard dose of nebulized albuterol reduces serum potassium by 0.2 to 0.4 mmol per liter (mEq/L).

Sunday March 7, 2010


Q: 26 year old female with recent history of abortion presented with hypotension, fever and severe abdominal pain. OB/Gyn service ordered intravenous urogram. Following abdominal film is obtained?

Answer: Uterine gas gangrene

Anaerobic infections with Clostridium perfringens (CP) occur rarely but are associated with considerable maternal mortality. Targeted antibiotics should be started ASAP. Surgery backup should be called to perform a hysterectomy and necrosis removal. Clostridium perfringens is ubiquitous and is found vaginally in 1 - 10 % of healthy women and usually does not cause a serious infection. Under the right conditions it can cause an endometritis leading to sepsis. Early recognition and interdisciplinary treatment are of extreme importance.

Saturday March 6, 2010


Q: What are Duret hemorrhages?

Answer: Duret hemorrhages of the midbrain and pons are small punctate hemorrhages that are often caused by arteriole stretching during the primary injury, as seen in the picture below (Duret hemorrhage in the splenium of the corpus callosum)

Friday March 5, 2010
TRALI - not very uncommon!


Objectives: To determine the incidence, risk factors, and outcome of transfusion-related acute lung injury in a cohort of critically ill patients.

Design: In a retrospective cohort study, patients with transfusion-related acute lung injury were identified using the consensus criteria of acute lung injury within 6 hrs after transfusion. Inclusion criterion was a length of intensive care unit admission more than 48 hrs. Patients developing transfusion-related acute lung injury were matched (on age, sex, and admission diagnosis) to transfused control subjects and patients developing acute lung injury from another origin.


Measurements and Main Results:

• Of 5208 admitted patients, 2024 patients had a length of stay more than 48 hrs, of whom 109 were suspected transfusion-related acute lung injury cases.
• Compared with transfused control subjects, risk factors for transfusion-related acute lung injury were emergency cardiac surgery, hematologic malignancy, massive transfusion, sepsis , mechanical ventilation and high Acute Physiology and Chronic Health Evaluation II score
• The volume of platelets and plasma transfused was associated with transfusion-related acute lung injury in the univariate analysis. However, this association disappeared in the multivariate analysis.
• Compared with acute lung injury control subjects, risk factors for transfusion-related acute lung injury were sepsis and high Acute Physiology and Chronic Health Evaluation II score whereas pneumonia was a negative predictive factor.
• Patients with transfusion-related acute lung injury had a longer duration of mechanical ventilation compared with transfused control subjects and acute lung injury control subjects
• Also, 90-day survival of patients with transfusion-related acute lung injury was lower compared with transfused control subjects and acute lung injury control subjects

Conclusions: Transfusion-related acute lung injury is common in critically ill patients. Transfusion-related acute lung injury may contribute to an adverse outcome associated with transfusion. This study identifies transfusion-related acute lung injury risk factors, which may aid in assessing the risks and benefits of transfusion in critically ill patients.



Risk factors and outcome of transfusion-related acute lung injury in the critically ill: A nested case-control study - Critical Care Medicine: March 2010 - Volume 38 - Issue 3 - pp 771-778

Thursday March 4, 2010
Transradial Versus Transfemoral Approach for Coronary Angiography and Angioplasty


Study Question: What is the relative safety and feasibility of the transradial versus transfemoral approach for coronary angiography and intervention?

Methods: The authors randomized a total of 1,024 patients undergoing coronary catheterization to the transradial or transfemoral approach. Patients with an abnormal Allen's test, history of CABG, simultaneous right heart catheterization, chronic renal insufficiency, or known difficulties with the radial or femoral access were excluded.

Results:

• Successful catheterization was more common in the femoral (99.8% vs. 96.5%) compared with the radial group.
• Procedure time (median procedural duration 37.0 minutes vs. 40.2 minutes, p = 0.046) and radiation exposure (median dose area product 38.2 Gycm2 vs. 41.9 Gycm2, p = 0.034) were significantly lower in the transfemoral group compared with the transradial access group.
• There was no difference in the amount of contrast media use between the two groups.
• Vascular access site complications were higher in the transfemoral group (3.71% vs. 0.58%, p = 0.0008).
  

Conclusions: The use of radial access is associated with an increased procedural duration and radiation exposure, and a marked reduction in vascular complications.

Editors' opinion: The reduction in groin complications and bleeding with the use of a radial approach has been highlighted in multiple studies. However, the increased radiation exposure to the patient and the operator is increasingly being recognized, and may translate into an increased late risk of malignancies. Better shielding strategies are needed to reduce this exposure so that the benefits of the radial approach can be obtained at minimal hazard to the patients or the operators.



JACC Cardiovasc Interv 2009;2:1047-1054

Wednesday March 3, 2010

Cardiac Tamponade on Echo

Tuesday March 2, 2010

Q: What is Redistributive hyponatremia?


Answer: Water shifts from the intracellular to the extracellular compartment, with a resultant dilution of sodium. The TBW (Total Body Water) and total body sodium are unchanged. This condition occurs with hyperglycemia or administration of mannitol.

Monday March 1, 2010

Q: Which steroid is preferable during treatment of Thyroid storm?


Answer: Dexamethasone (Decadron)

Dexamethasone (2 mg every 6 hours during first 24 hours) not only inhibit hormone production but also decreases peripheral conversion from T4 to T3. After acute episode subsides and there is an indication or suspicion of adrenal insufficiency Hydrocortisone (Solu-Cortef) 100 mg IV every 8 hours should be given.