Friday, December 31, 2010
A) Hepatic failure
B) Renal failure
C) Geriatric patients
E) Both C and D
Answer: E (Both C and D)
Half life of Nimbex is approximately 22 to 29 minutes, following administration of a single intravenous dose. The half-life is not substantially affected by the duration of administration (approximately 26 ± 11 minutes in ICU patients receiving cisatracurium via intravenous infusion), type of anesthesia, or hepatic or renal function impairment, but is slightly longer in geriatric patients than in younger adults. In individuals undergoing induced hypothermia (body temperature of 25 to 28 °C), the half-life is prolonged as compared with the half-life during normothermia.
Thursday, December 30, 2010
Q: Where should ICP monitoring be leveled (zeroed)?
Answer: The transducer is supposed to be leveled at the part of the patient’s face that corresponds to the Foramen of Monro. Few external points describe are:
1. The outer canthus of the eye.
2. Halfway between the outer canthus of the eye and the tragus of the ear.
3. Patient’s external auditory meatus.
4. If the patient is lateral, between the eyebrows.
(Laser pointing device is recommended by many).
Wednesday, December 29, 2010
Q: What is singers' emboli?
Answer: Helium gas emboli in singers
An interesting cause of "Helium emboli" can occur from inhalation of pressurized helium. Some singers intentionally inhale high-pressure helium for entertainment or to produce a change in their voice. Inhaled high-pressure gas can produce high transpulmonary pressure sufficient to rupture alveoli and surrounding blood vessels, introducing gas into the pulmonary veins and allowing systemic embolization through the left heart; particularly in an upright person!
But more common cause of "helium emboli" is from IABP. Intra Aortic Balloon Pump (IABP) Counterpulsation utilizes helium gas to inflate its balloon. As Helium is a low density as well as an inert gas, in case of balloon rupture it is easily absorbed into the bloodstream. But fairly well numbered incidents of "Helium emboli" after balloon rupture have been described in literature.
Major clinical sign of helium embolus is neurological deficit associated with other findings of balloon rupture as blood in the tubing. Treatment is hyperbaric oxygen.
1. Cerebral and coronary gas embolism from the inhalation of pressurized helium Critical Care Medicine: May 2002 - Volume 30 - Issue 5 - pp 1156-1157
2. Cerebral Gas Embolism Resulting From Inhalation of Pressurized Helium - Annals of Emergency Medicine Volume 28, Issue 3, Pages 363-366, September 1996
Tuesday, December 28, 2010
Answer: The V-sign of Naclerio
The V-sign of Naclerio (see Arrows) is present in about one fourth of patients with esophageal perforation. These are radiolucent streaks of air that dissect the fascial planes behind the heart to form the shape of the letter V. It is a fairly specific radiographic sign of esophageal perforation.
Monday, December 27, 2010
PPIs in COPD?
OBJECTIVES: To investigate whether proton pump inhibitor (PPI) therapy reduces the frequency of common colds and exacerbations in patients with chronic obstructive pulmonary disease (COPD).
DESIGN: Twelve-month, randomized, observer-blind, controlled trial in a university hospital and three city hospitals in Miyagi prefecture in Japan.
PARTICIPANTS: One hundred patients with COPD (mean age +/- SD 74.9 +/- 8.2) participated. They were all ex-smokers and had received conventional therapies for COPD, including smoking cessation and bronchodilators. Patients with gastroesophageal reflux disease or gastroduodenal ulcer were excluded.
INTERVENTION: Patients were randomly assigned to conventional therapies (control group) or conventional therapies plus PPI (lansoprazole 15 mg/d; PPI group) and observed for 12 months.
MEASUREMENTS: Frequency of common colds and COPD exacerbations.
RESULTS: The number of exacerbations per person in a year in the PPI group was significantly lower than that in the control group (0.34 +/- 0.72 vs 1.18 +/- 1.40). The adjusted odds ratio with logistic regression for having exacerbation in the PPI group compared with the control group was 0.23 (P=.004). In contrast, there was no significant difference in the numbers of common colds per person per year between the PPI group and the control group (1.22 +/- 2.09 vs 2.04 +/- 3.07; P=.12). PPI therapy significantly reduced the risk of catching frequent common colds (more than or =3 times/year), the adjusted odds ratio of which was 0.28 (P=.048).
CONCLUSION: In this single-blind, nonplacebo-controlled trial, lansoprazole was associated with a significant decrease in COPD exacerbations. More definitive clinical trials are warranted.
(click) A randomized, single-blind study of lansoprazole for the prevention of exacerbations of chronic obstructive pulmonary disease in older patients. - J Am Geriatr Soc.2009 Aug;57(8):1453-7. Epub 2009 Jun 8.
Sunday, December 26, 2010
Q: 32 year old diabetic female is admitted with fever, chills, abdominal pain, nausea, vomiting, left flank pain with crepitation over left flank and urinary symptoms. What's your concern?
Answer: Emphysematous pyelonephritis
Emphysematous pyelonephritis is a necrotizing acute nephritis with extension of the infection through the renal capsule. This leads to the presence of gas within the kidney and in the perinephric space.
The mortality rate is 60% - 80% despite medical treatment and usually require surgical intervention with nephrectomy.
Saturday, December 25, 2010
Friday, December 24, 2010
Some of the common medications that may cause dark green or blue urine include amitriptyline, cimetidine, indomethacin and phenergan.
Thursday, December 23, 2010
Rhabdomyolysis after consuming quail meat is called "coturnism" (after Coturnix, the main quail genus). Migrating quail consume large amounts of hemlock, which contains the poisonous alkaloid coniine. Coniine may cause rhabdomyolysis.
Wednesday, December 22, 2010
AG = Na+ - (Cl- + CO2)
Answer: Lithium toxicity
Lithium is basically read as a charged ion which may give very low or even negative an-ion gap.
Overdose of cough syrup containing dextromethorphan bromide may do the same as bromide may get measured as chloride.
Other 2 conditions known to do that are: hypo-proteinemia and multiple myeloma.
Tuesday, December 21, 2010
Monday, December 20, 2010
Dialysis dementia occurs in patients on chronic hemodialysis. It has been said due to toxicity from aluminum in the dialysis bath. The incidence of the disease has decreased with the use of aluminum-free water.
Symptoms are dysarthria, apraxia, slurred speech, stuttering and hesitation. Later myoclonus, asterixis, seizures, personality changes and frank psychosis are reported with frequent suicide. Disease has variable course. Within few months, the disease may even progress to apneic spells. In some patients, however, the disease is transient. Drug-resistant seizures are said to be part of it but it is mostly due to removal of pyridoxine during hemodialysis.
Treatment is to stop aluminum-containing phosphate binders. Aluminum chelation with deferoxamine lead to dramatic improvement. Control of secondary hypoparathyroidism, iron deficiency anemia, and hyperphosphatemia reduces aluminum absorption by the gastrointestinal tract. The concentration of aluminum in the dialysate should be monitored too. Pyridoxine supplementation must be given. Benzodiazepines are effective in controlling the myoclonus. Phenytoin is used for tonic-clonic seizures because relatively little is removed by hemodialysis.
Sunday, December 19, 2010
Q: Describe 3 effects of Fludrocortisone (Florinef)?
Answer: Fludrocortisone (Florinef) acts on renal distal tubules and
Increases reabsorption of sodium (remarkably)
Increases excretion of potassium and
Increases excretion of hydrogen ions
Unfortunately it is an under utilized drug in ICU.
Saturday, December 18, 2010
Answer: To prevent vasospasm and improve outcome after aneurysmal subarachnoid hemorrhage, it is recommended to keep a magnesium level of 3-4.5mEq/l
Central line is suggested for administration. Bolus Dose of 2g of MgSO4 is given over 30 minutes and maintenance rate of 1g of MgSO4/hr is recommended with goal of serum Mg level of 3-4.5 mEq/l. Serum Mg levels should be checked before starting the infusion, 2 hours after initiation, 2 hours after any dose or rate change and every 12 hours afterwards.
It is to note that ionized Ca and serum K levels should be checked twice a day. Calcium repletion is needed if Calcium level is less than 1.1mmol/L. Magnesium drip should be stopped if serum K is greater then 6 mmol/L or if there is a new prolongation of PR interval or onset of new AV block.
Friday, December 17, 2010
Answer: Chylous ascites is defined as the presence of ascitic fluid with triglyceride higher than 110 mg/dL. Another defination described is - Ascites:Plasma ratio of Triglyceride more than 2.
It may occur due to various reasons including abdominal trauma, malignant neoplasms such as hepatoma or lymphoma, spontaneous bacterial peritonitis, cirrhosis, irradiation, abdominal tuberculosis and others.
Chylous ascites requires treatment of underlying cause. A low-fat diet with medium-chain triglyceride supplementation can reduce the flow of chyle into the lymphatics. It may also require patient to be NPO and be on TPN. If dietary measures fail, peritoneovenous shunting may be successful.
Thursday, December 16, 2010
Hint: Its drug interaction question
Answer: Patient is probably on warfarin for her A. fib. and Phenytoin increases effects of warfarin. Actual basis of interaction is unknown.
The Multidisciplinary Medication Management Project (joint collaboration of the American Society of Consultant Pharmacists and the American Medical Directors Association) - lists phenytoin and warfarin among its top 10 drug interactions.
Wednesday, December 15, 2010
Background: In this randomized clinical trial, we aimed to determine whether increasing the frequency of in-center hemodialysis would result in beneficial changes in left ventricular mass, self-reported physical health, and other intermediate outcomes among patients undergoing maintenance hemodialysis.
Methods: Patients were randomly assigned to undergo hemodialysis six times per week (frequent hemodialysis, 125 patients) or three times per week (conventional hemodialysis, 120 patients) for 12 months.
The two coprimary composite outcomes: were death or change (from baseline to 12 months) in left ventricular mass, as assessed by cardiac magnetic resonance imaging, and death or change in the physical-health composite score of the RAND 36-item health survey.
Secondary outcomes: included cognitive performance; self-reported depression; laboratory markers of nutrition, mineral metabolism, and anemia; blood pressure; and rates of hospitalization and of interventions related to vascular access.
- Patients in the frequent-hemodialysis group averaged 5.2 sessions per week; the weekly standard Kt/Vurea (the product of the urea clearance and the duration of the dialysis session normalized to the volume of distribution of urea) was significantly higher in the frequent-hemodialysis group than in the conventional-hemodialysis group.
- Frequent hemodialysis was associated with significant benefits with respect to both coprimary composite outcomes.
- Patients randomly assigned to frequent hemodialysis were more likely to undergo interventions related to vascular access than were patients assigned to conventional hemodialysis.
- Frequent hemodialysis was associated with improved control of hypertension and hyperphosphatemia.
- There were no significant effects of frequent hemodialysis on cognitive performance, self-reported depression, serum albumin concentration, or use of erythropoiesis-stimulating agents.
Note: The length of the session in daily dialysis group was between 1.5 and 2.75 hours.
In-Center Hemodialysis Six Times per Week versus Three Times per Week - (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; ClinicalTrials.gov number, NCT00264758.) - N Engl J Med 2010; 363:2287-2300, December 9, 2010
Tuesday, December 14, 2010
Answer: C (Phenylephrine)
Beisde its role as a vasopressor, Phenylephrine can be an effective treatment for PSVT particularly in patients with PWP (Wolff-Parkinson-White syndrome), including refractory cases. Phenylephrine stimulates the baroreceptors and therefore decreases vagal output.
Dose of Phenylephrine in PSVT is 0.5 mg rapid IV push. Subsequent doses may be given.
Waxman MB, Wald RB, Sharma AD, et al: Vagal techniques for termination of paroxysmal supraventricular tachycardia. Am J Cardiol 1980;46:655-664.
Monday, December 13, 2010
Answer: Estrogens improve bleeding time and decrease clinical bleeding significantly particularly in uremic patients. The dose is 0.6 mg/kg IV over 30 minutes per day. It can be repeated upto 5 days.The time to onset of action is about 6 hours. Estrogens have also been successfully used in patients with GI bleed in patients with uremic platelet dysfunction.
Mechanism of action: It has been postulated that the hormones decrease production of L-arginine, which is a precursor of NO. By decreasing NO concentrations, which seem to be higher in uremia, there is less guanylyl cyclase stimulation and less production of cGMP. This potentially leads to increased production of TxA2 and ADP, which are crucial contributors to formation of platelet plugs. Also estrogen decrease antithrombin III and protein S levels, and increase factor VII concentrations, might contribute to the therapeutic effect in this clinical situation.
Sunday, December 12, 2010
Dr. Sam Schulman from Karolinska Hospital, Stockholm, Sweden wrote an excellent review on "Care of Patients Receiving Long-Term Anticoagulant Therapy" in August 14, 2003 issue of NEJM. Part of article suggest formula for amount of FFP (Fresh Frozen Plasma) to correct INR upto desired level in a bleeding patient from over-anticoagulation.
The "percentage" is prothrombin complex, expressed as a percentage of normal plasma, corresponds to the mean level of the vitamin K–dependent coagulation factors. It can be compute easily with following table:
INR 1 = 100 (%)
INR 1.4 - 1.6 = 40
INR 1.7 - 1.8 = 30
INR 1.9 - 2.1 = 25
INR 2.2 - 2.5 = 20
INR 2.6 - 3.2 = 15
INR 4.0 - 4.9 = 10
INR > 5 = 5 (%)
Example: In a 70 kg patient bleeding with INR of 7.5 and if our target is to bring INR down to 1.4, using above table:
Total FFP needed = (40 - 5) x 70 = 2450 ml
(One unit FFP usually contains 200-250 ml of FFP)
Care of Patients Receiving Long-Term Anticoagulant Therapy - NEJM - Volume 349:675-683, August 14, 2003
Saturday, December 11, 2010
Friday, December 10, 2010
Hepatic encephalopathy is subdivided in type A, B and C depending on the underlying cause.
Type A (=acute) describes hepatic encephalopathy associated with acute liver failure.
Type B (=bypass) is caused by portal-systemic shunting without associated intrinsic liver disease.
Type C (=cirrhosis) occurs in patients with cirrhosis.
Thursday, December 9, 2010
A: Diazepam and lorazepam.
Also, barbiturates, may be effective in controlling seizures because they may act synergistically with the benzodiazepines.
Important pearl to remember is: Phenytoin may not be effective against cocaine-induced seizures.
Wednesday, December 8, 2010
Tuesday, December 7, 2010
Answer: Vomitting induce volume depletion which causes hypokalemia by 3 systemic effects.
1. Volume depletion leads to secondary hyperaldosteronism, which, in turn, causes enhanced cortical collecting tubule secretion of potassium in response to enhanced sodium reabsorption.
2. Metabolic alkalosis which increases collecting tubule potassium secretion due to the decreased availability of hydrogen ions for secretion in response to sodium reabsorption.
3. Metabolic alkalosis directly enhances potassium entry into cells.
Monday, December 6, 2010
3-11% of patients may develop hypokalemia. Other adverse lab abnormalities include eosinophilia, anemia, decreased white blood cell count, elevations in liver function tests and serum bilirubin.
Sunday, December 5, 2010
Cryptococcosisis is a systemic or central nervous system (CNS) fungal infection caused by the yeast Cryptococcus neoformans . Cryptococcal infection is usually asymptomatic and self-limited. In patients with advanced HIV infection (eg, those with CD4 counts less than 100 cells/µL), Cryptococcus may cause life-threatening illness, either from a new exposure or through reactivation of a previously acquired latent infection. One of the hallmark is elevated ICP. Elevated ICP significantly increases the morbidity and mortality of cryptococcal meningitis and should be treated by the removal of CSF. The CSF opening pressure should be checked on the initial LP. LP and CSF removal should be repeated daily as needed for ICP reduction. Ventriculostomy or a ventriculoperitoneal (VP) shunt may be needed if the initial opening pressure is more than 400 mm H2O, or in refractory cases.
Recommended Reading: EDITORIAL REVIEW: HIV-associated cryptococcal meningitis, Joseph N. Jarvis and Thomas S. Harrison, AIDS 2007, 21:2119–2129
Saturday, December 4, 2010
1. Metronidazole-Induced and Wernicke Encephalopathy: Two Different Entities Sharing the Same Metabolic Pathway? (Letter) -American Journal of Neuroradiology 29:e84, October 2008
Friday, December 3, 2010
These are biggest infectious threats in view of their rising resistance and no new novel antibiotics coming in pipeline!
Thursday, December 2, 2010
Olanzapine (Zyprexa) is an antipsychotic in the thienobenzodiazepine class that blocks multiple neurotransmitters in brain. Olanzapine, relieves nausea in some patients failing to respond to the usual antiemetics. Studies have shown the effectiveness of olanzapine as an antiemetic. Olanzapine combined with a single dose of dexamethasone and a single dose of palonosetron is found to be very effective in controlling acute severe nausea.
Olanzapine as an Antiemetic in Refractory Nausea and Vomiting in Advanced Cancer - Journal of Pain and Symptom Management, Volume 25, Issue 6, Pages 578-582 (June 2003)
Wednesday, December 1, 2010
Filgrastim (Neupogen): is a granulocyte colony-stimulating factor (G-CSF) analog used to stimulate the proliferation and differentiation of granulocytes in neutropenic patients. It can be given subcutaneously or intravenously. Usual dose is 5 mcg per kg of weight daily.
Pegfilgrastim (Neulasta): When compared to filgrastim, pegfilgrastim has an added polyethylene glycol molecule which reduces renal clearance and prolongs persistence in vivo (half life range: 46-62 hours). Pegfilgrastim can be given on the first day of chemotherapy.The effects of one dose of pegfilgrastim last fourteen days. It can only be given subcutaneously and not intravenously. The recommended dosage is a single subcutaneous injection of 6 mg administered once per chemotherapy cycle.