icuroom.net April 2010 Archive

2010-04-30T09:26:00.000-07:00

Friday April 30, 2010
Treatment of TB by inducing Artificial Pneumothorax

OBJECTIVE: To determine the usefulness of artificial pneumothorax (AP) in the management of pulmonary tuberculosis (PTB) patients when anti-tuberculosis treatment is ineffective.

DESIGN: We evaluated the outcome of therapy in 214 patients with cavitary PTB bacteriologically confirmed by culture treated during 1998–2004, 78.9% of whom had multidrug resistance. AP was applied in 109 patients (56 newly diagnosed TB and 53 retreatment cases). A control group consisted of 105 patients (respectively 55 and 50) treated without AP. The average period of AP application was 4.5 months for newly diagnosed patients and 9 months in retreatment cases. Anti-tuberculosis treatment regimens in both groups were based on drug susceptibility test results.

RESULTS:
Culture negativity was achieved in patients treated with AP in all new cases and in 81.1% of retreatment cases.
Cavity closure occurred in 94.6% and 67.9% respectively.
In the control group, culture negativity was achieved in respectively 70.9% and 40.0%, and cavity closure occurred in respectively 56.3% and 24.0%.

CONCLUSION: AP considerably improved the treatment outcome in both newly diagnosed and retreatment patients. This procedure can be considered a useful addition in managing certain patients with cavitary TB, particularly those with drug resistance.

Reviving an old idea: can artificial pneumothorax play a role in the modern management of tuberculosis? - The International Journal of Tuberculosis and Lung Disease, Volume 10, Number 5, May 2006 , pp. 571-577(7)

2010-04-29T11:29:00.000-07:00

Thursday April 29, 2010

Q: Which finding in CBC is highly suggestive of Adrenal crisis? (Select one)

A) Neutrophilia
B) Eosinophilia
C) Thrombocytopenia
D) Neutropenia
E) Polycythemia

Ans: Eosinophilia

Hyponatremia, hyperkalemia, metabolic acidosis, and hypoglycemia may be present along with anemia and lymphocytosis, but eosinophilia with above serum chemistry findings is highly suggestive of Adrenal Crisis.

2010-04-28T06:19:00.000-07:00

Wednesday April 28, 2010
A- lines not as safe either!

Background: Arterial catheters are considered at lower risk for catheter-related infection than central venous catheters in the absence of conclusive evidence. Study was to compare the daily risk and risk factors for colonization and catheter-related infection between arterial catheters and central venous catheters.

Methods: We used data from a trial of seven intensive care units evaluating different dressing change intervals and a chlorhexidine-impregnated sponge. We determined the daily hazard rate and identified risk factors for colonization using a marginal Cox model for clustered data.

Results: We included 3532 catheters and 27,541 catheter-days.

Colonization rates did not differ between arterial catheters and central venous catheters (7.9% vs 9.6%)
Arterial catheter and central venous catheter catheter-related infection rates were 0.68% and 0.94% respectively.
The daily hazard rate for colonization increased steadily over time for arterial catheters (p = .008) but remained stable for central venous catheters.
Independent risk factors for arterial catheter colonization were respiratory failure and femoral insertion
Independent risk factors for central venous catheter colonization were trauma or absence of septic shock at intensive care unit admission, femoral or jugular insertion, and absence of antibiotic treatment at central venous catheter insertion

Conclusions: The risks of colonization and catheter-related infection did not differ between arterial catheters and central venous catheters, indicating that arterial catheter use should receive the same precautions as central venous catheter use. The daily risk was constant over time for central venous catheter after the fifth catheter day but increased significantly over time after the seventh day for arterial catheters. Randomized studies are needed to investigate the impact of scheduled arterial catheter replacement.

Infectious risk associated with arterial catheters compared with central venous catheters - Critical Care Medicine. 38(4):1030-1035, April 2010.

2010-04-27T06:35:00.000-07:00

Tuesday April 27, 2010

Q: What does it mean by SASH Method?

Answer: SASH stands for

Saline
Administration of Drug
Saline
Heparin

The SASH method is the standard protocol for PICC line care as with most of the special types of IV catheters. It sounds simple but very crucial in prevention of PICC lines' complications. Hospitals are suppose to have standard protocol in this regard.

2010-04-26T03:41:00.000-07:00

Monday April 26, 2010

Q: 42 year male with no previous history known is brought to ER with mental status change, fever and nuchal rigidity. CT scan is not much of information. ER doc performed lumbar punture and transferred patient to ICU. You get STAT call from lab that there is a spiderweb clot in the collected CSF. What does it mean?

Answer: A spiderweb clot in the collected CSF is characteristic of TB meningitis though not always present.

The CSF usually has a high protein, low glucose and a increase lymphocytes. Acid-fast bacilli commonly grown in culture but the culture of TB from CSF takes about two weeks, and therefore the majority of patients with TB meningitis are started on treatment before the diagnosis is confirmed.

2010-04-25T00:24:00.000-07:00

Sunday April 25, 2010
Comprehensive strategies to prevent VAP (ventilator-associated pneumonia)

Although the IHI VAP-prevention bundle includes the following 4 strategies:
Semirecumbent patient positioning, to at least 30 degrees
Ventilator weaning, via periodic sedation vacations and daily assessment of extubation readiness.
Peptic ulcer disease (PUD) prophylaxis.
Deep-vein thrombosis (DVT) prophylaxis.
- there are other strategies should be taken into account too

1. Semirecumbent positioning: Elevating the heads of ICU patients’ beds between 30 and 45 degrees (with the exception of certain fracture and post-neurosurgery patients and those with severe hypotension).

2. Sedation holiday: It is well established that the sooner patients are extubated, the lower their risk of developing VAP.

3. Continuous subglottic secretion removal: Several trials support the benefits of using tubes that continuously drain these secretions.

4. Oral vs. nasal feeding tubes: A growing body of evidence suggests that oral tubes may be better than nasal tubes in preventing VAP, Dr. Boiteau notes, but the evidence is largely inferential.

5. Oral hygiene with use of oral chlorhexidine gluconate washes: Strategies like stimulation of the gums, toothbrushing and use of oral washes—these practices are so benign and inexpensive that they are worth trying.

6. Stress ulcer prophylaxis: In general, the role of gastric pH in development of VAP remains poorly understood, and the practice could increase infection risks in some patients.

7. Selective digestive tract decontamination: While this practice is widely used to prevent VAP in Europe, experts say that it doesn’t translate well to North America. The problem has to do with well-known antibiotic-resistance issues in ICUs.

8. Deep-vein thrombosis (DVT) prophylaxis (unless contraindicated)

Reference:

Seven strategies to prevent VAP: a look at the evidence Why some popular approaches, from handwashing to good oral hygiene, may not be as evidence-based as you think by Bonnie Darves Published in the May 2005 issue of Today's Hospitalist

2010-04-24T07:36:00.000-07:00

Saturday April 24, 2010

Question: Is Keppra (Levetiracetam) dialyzable?

Answer: Yes!

Keppra (Levetiracetam), an anti-epileptic drug is now available in IV form and is frequently used in ICU. Its important to remember that Keppra metabolized through kidney and dose needs to be reduced in renal insufficiency by 50%. Also keppra is dialyzable and ideally should be given after dialysis on dialysis.

2010-04-23T10:03:00.000-07:00

Friday April 23, 2010

Question: 52 year old male post-MI is started on cholesterol lowering drug Zetia (Ezetimibe). Patient developed severe diarrhea. How its related to drug's mechanism of action?

Answer: Ezetimibe localises at the brush border of the small intestine, where it inhibits the absorption of cholesterol from the intestine.

Specifically, it appears to bind to a critical mediator of cholesterol absorption, the Niemann-Pick C1-Like 1 (NPC1L1) protein on the gastrointestinal tract epithelial cells. Diarrhea happens in 4.1% of patients.

2010-04-22T00:25:00.000-07:00

Thursday April 22, 2010

Question: What is the choice of diuretics in initial treatment of life threatening hypercalcemia?

Answer: Loop diuretics

The initial management in severe hypercalcemia is hydration with saline. Hydration helps decrease the calcium level through dilution. The expansion of extracellular volume also increases the renal calcium clearance - but vigilance to prevent volume overload is critical and may require diuretics with saline hydration. A loop diuretic (like furosemide) should be used with hydration to increase calcium excretion. This also prevents volume overload during therapy. Thiazide diuretics should be avoided because they increase the reabsorption of calcium.

2010-04-21T11:24:00.000-07:00

Wednesday April 21, 2010
Oral Care Protocol for VAP (Ventilator-associated Pneumonia)

Objective: The purpose of this study was to determine the effects of a simple low-cost oral care protocol on ventilator-associated pneumonia rates in a surgical intensive care unit.

Design: Preintervention and postintervention observational study in 24 beds surgical/trauma/burn intensive care units in an urban university hospital of all mechanically ventilated patients.

Interventions: An oral care protocol to assist in prevention of bacterial growth of plaque by cleaning the patients' teeth with sodium monoflurophosphate 0.7% paste and brush, rinsing with tap water, and subsequent application of a 0.12% chlorhexidine gluconate chemical solution done twice daily at 12-hour intervals.

Results:

During the preintervention period there were 24 infections in 4606 ventilator days (rate = 5.2 infections per 1000 ventilator days). After the institution of the oral care protocol, there were 10 infections in 4158 ventilator days, resulting in a lower rate of 2.4 infections per 1000 ventilator days. This 46% reduction in ventilator-associated pneumonia was statistically significant (P = .04).
Staff compliance with the oral care protocol during the 12-month period was averaged 81%.
The total cost decrease in cost of US$140 000 to US$560 000 based on the estimated cost per ventilator-associated pneumonia infection of US$10 000 to US$40 000.
There was an overall reduction in ventilator-associated pneumonia without a change to the gram-negative or gram-positive microorganism profile.

Conclusions: The implementation of a simple, low-cost oral care protocol in the surgical intensive care unit led to a significantly decreased risk of acquiring ventilator-associated pneumonia.

The Impact of a Simple, Low-cost Oral Care Protocol on Ventilator-associated Pneumonia Rates in a Surgical Intensive Care Unit - Journal of Intensive Care Medicine, Vol. 24, No. 1, 54-62 (2009)

2010-04-20T09:16:00.000-07:00

Tuesday April 20, 2010

Q: A critically ill patient in ICU is requiring frequent platelet transfusions. Family wants to know that how frequent a family member can donate platelets?

Answer: The body replenishes platelets immediately. Technically, this enables a donor to donate as frequently as every 72 hours. However per guidlines donors may not donate platelets more than 12 times a year.

2010-04-19T02:17:00.000-07:00

Monday April 19, 2010
Cocaine-Induced Pneumopericardium

Likely use of "crack" cocaine with solid contaminants in the crystalline mass could may cause a microscopic esophageal tear and eventually produce a leak of air into the pericardial sac.

See interesting case report here (Circulation. 2000;102:2792)

CXR shows linear detachment along silhouette of left ventricle and left atrium (arrows)

2010-04-18T02:54:00.000-07:00

Sunday April 18, 2010

Q: Describe "Peak" and "Trough" Anti-Xa test?

Answer: Anti-Xa tests are sometimes ordered to monitor and adjust Low molecular weight heparin (LMWH) therapy. It may also be use to monitor unfractionated heparin (UFH) concentrations in the blood instead of primary monitoring tool of PTT test.

"Peak" Anti-Xa test: When it is used as a LMWH monitoring tool, anti-Xa is primarily ordered as a “peak” test. It is collected about 4 hours after a LMWH dose is given, when the concentration of LMWH in the blood is expected to be at its highest level.

"Trough" Anti-Xa test: “Trough” anti-Xa tests may also be ordered when it is suspected that a patient may not be clearing the LMWH at a normal rate. Trough tests are collected just prior to the next dose, when heparin concentrations are expected to be at their lowest.

2010-04-17T00:01:00.000-07:00

Saturday April 17, 2010

Trivia: FFP (Fresh Frozen Plasma) can be stored/preserved for maximum of what time period?

Answer: 3 years

One study showed that an extended storage for up to 3 years at - 40 °C should be possible without clinically relevant loss of efficacy 1.

Fresh Frozen Plasma is the fluid portion of one unit of human blood that has been centrifuged, separated, and frozen solid usually at −18 °C within 8 hours of collection.

Long-Term Storage of Fresh Frozen Plasma at -40 °C. A Multicenter Study on the Stability of Labile Coagulation Factors over a Period of 3 Years - Infusion Therapy and Transfusion Medicine 2001;28:189-194

2010-04-16T00:54:00.000-07:00

Friday April 16, 2010

Scenario: 32 year old male with history of cirrhosis admitted to ICU with frank upper GI bleed. You called gastroenterologist STAT. On arrival to ICU gastroenterologist instead of coming to patient's bed rushed towards unit's refrigerator. What he is looking for?

Answer: A Sengstaken-Blakemore tube

The tube is often kept in the refrigerator in the hospital's ICUs emergency departments and intensive care units to reduce its flexibility during insertion.

2010-04-15T10:54:00.000-07:00

Thursday April 15, 2010

Q: What could be the supporting laboratory finding in (Transfusion-related acute lung injury (TRALI)?

Answer: Laboratory findings may include unexpected haemoconcentration and a sudden fall in serum albumin. As in other causes of acute alveolar capillary leak, the pulmonary exudate in TRALI has a high albumin content. Peripheral blood neutropenia has been reported but neutrophilia is more common.

2010-04-14T18:30:00.000-07:00

Wednesday April 14, 2010
Endovascular versus Open Repair of Abdominal Aortic Aneurysm

Background: Few data are available on the long-term outcome of endovascular repair of abdominal aortic aneurysm as compared with open repair.

Methods: From 1999 through 2004 at 37 hospitals in the United Kingdom, we randomly assigned 1252 patients with large abdominal aortic aneurysms (5.5 cm in diameter) to undergo either endovascular or open repair; 626 patients were assigned to each group. Patients were followed for rates of death, graft-related complications, reinterventions, and resource use until the end of 2009.

Results

The 30-day operative mortality was 1.8% in the endovascular-repair group and 4.3% in the open-repair group (P=0.02).
The endovascular-repair group had an early benefit with respect to aneurysm-related mortality, but the benefit was lost by the end of the study, at least partially because of fatal endograft ruptures (P=0.73).
By the end of follow-up, there was no significant difference between the two groups in the rate of death from any cause (P=0.72).

The rates of graft-related complications and reinterventions were higher with endovascular repair, and new complications occurred up to 8 years after randomization, contributing to higher overall costs.

Conclusions: In this large, randomized trial, endovascular repair of abdominal aortic aneurysm was associated with a significantly lower operative mortality than open surgical repair. However, no differences were seen in total mortality or aneurysm-related mortality in the long term. Endovascular repair was associated with increased rates of graft-related complications and reinterventions and was more costly.

Endovascular versus Open Repair of Abdominal Aortic Aneurysm - Published at www.nejm.org April 11, 2010

2010-04-13T00:45:00.000-07:00

Tuesday April 13, 2010

Q: 58 year old male is in ICU after cardiac surgery. Patient is showing significant post-operative bleeding. Patient continue to bleed despite correction of all coagulation profiles via blood products. Surgeon wants to try more conservative measures before taking back to OR due to high risk and associated morbidities. While going through chart you find that patient has history of anaphylaxis with use of bovine meat. Which one intervention is out of question?

Answer: Use of Factor 7

Factor -seven is contraindicated in patients with known hypersensitivity to mouse, hamster, or bovine proteins. NovoSeven contains amounts of proteins derived from the manufacturing and purification processes such as mouse IgG (maximum of 1. 2 ng/mg), bovine IgG (maximum of 30 ng/mg), and protein from BHK-cells and media (maximum of 19ng/mg).

2010-04-12T00:24:00.000-07:00

Monday April 12, 2010

Q: 51 year old male with previous history of Asthma presented to ER with frequent episodes of supra-ventriculat tachycardia (SVT). As you enter patient's room you are amused by the fact that though heart rate on monitor is 180/minutes patient is drinking a cup of coffee.You administered adenocard twice with maximum dose but there is no response. What could be the reason?

Answer: Patient has history of Asthma and could be on theophylline. Also, patient's intake of caffeine may be masking the effect of Adenosine.

Theophylline/aminophylline antagonize actions of Adenocard. Another major culprit could be caffeine. By nature of caffeine's purine structure it binds to some of the same receptors as adenosine. The pharmacological effects of adenosine may therefore be blunted in individuals who are taking large quantities of methylxanthines (e.g., caffeine, found in coffee and tea, or theobromine, as found in chocolate).

2010-04-11T00:28:00.000-07:00

Sunday April 11, 2010

Q: What is the advantage of Tolvaptan (Samsca) over Conivaptan (Vaprisol) in treatment of hyponatremia?

Answer: It can be given orally.

Tolvaptan (Samsca) is a selective vasopressin V2 -receptor antagonist. Indicated for hypervolemic and euvolemic hyponatremia (ie, serum sodium level less than 125 mEq/L) or less marked hyponatremia that is symptomatic and has resisted correction with fluid restriction. Dose is 15 mg PO qd initially; may increase at 24-h intervals to 30 mg/d but not to exceed 60 mg/d.

Conivaptan (Vaprisol) is a Arginine vasopressin antagonist (V1A, V2) indicated for euvolemic (dilutional) and hypervolemic hyponatremia. Increases urine output of mostly free water, with little electrolyte loss. Dose is 20 mg IV loading dose (infuse over 30 min), followed by 20 mg via continuous IV infusion over 24 h; continue treatment for additional 1-3 d as a 20-mg/d continuous IV infusion; may titrate up to 40 mg/d if necessary.

2010-04-10T00:21:00.000-07:00

Saturday April 10, 2010
One doctor's small effusion is another's nighmare

One day, when I was on a very busy hospitalist service, the ER called me with an admission. "I've got a 35 year old woman, shoots meth, smokes, uncontrolled diabetic, comes in with shortness of breath," the harried ER attending reported. "X-ray looks like a bilateral pneumonia, and some parapneumonic effusions too, but not enough to tap. Oh, and she's pregnant, about 14 weeks by LMP. She's stable but the last bed we have is in ICU, so that's where she's going.....

.........I examined her. She could only take shallow, mouse-like breaths and it looked as if she had to concentrate all her energy on mobilizing those breaths. I could barely hear any breath sounds at the bases of her lungs. I lost tactile fremitus in the middle of her left lung and heard egophony changes at the left base. When I palpated her belly, the top of her uterus rose well above her belly button, which suggested a gestational age over 20 weeks.

Read full post here

2010-04-09T09:51:00.000-07:00

Friday April 9, 2010

Q; Bone marrow suppression, characterized particularly by thrombocytopenia (low platelet count), may occur during linezolid treatment but it is reversible. Less frequent side effect of Linezolid are peripheral neuropathy and optic neuropathy. Are they

A) reversible or
B) irreversible?

A; Irreversible

Long-term use of linezolid has also been associated with peripheral neuropathy and optic neuropathy, which is most common after several months of treatment and may be irreversible. Although the mechanism of injury is still poorly understood, mitochondrial toxicity has been proposed as a cause, linezolid is toxic to mitochondria, probably because of the similarity between mitochondrial and bacterial ribosomes.

A more extensive monitoring protocol for early detection of toxicity in seriously ill patients receiving linezolid has been developed and proposed by a team of researchers in Melbourne, Australia. The protocol includes twice-weekly blood tests and liver function tests; measurement of serum lactate levels, for early detection of lactic acidosis; a review of all medications taken by the patient, interrupting the use of those that may interact with linezolid; and periodic eye and neurological exams in patients set to receive linezolid for longer than four weeks.

2010-04-08T21:48:00.001-07:00

Thursday April 8, 2010
Factor-7 in GI bleed

Case; 67 year old male admitted with acute GI bleed seconday to coumadin (warfarin) overdose with INR more than 7. You ordered, pRBC, FFP (fresh frozen plasma) and IV vitamin K. But you are afraid that patient may not survive before all the infusions are available. What could be your choice in such desperation?

A; recombinant FVIIa (Novo seven)

In many anecdotal reports (see references), novoseven has showed very quick reversal of PT / INR.

References:

1. Recombinant factor VIIa corrects prothrombin time in cirrhotic patients: A preliminary study: Gastroenterology 113:1930-1937, 1997

2. Recombinant factor VIIa (rFVIIa) successfully and rapidly corrects the excessively high international normalized ratios (INR) and prothrombin times induced by warfarin. Blood 96 (11 Part 1): 638a, 2000

3. Reversal of Warfarin-Induced Excessive Anticoagulation with Recombinant Human Factor VIIa Concentrate. Ann Inter Med. 137:884-888, 2002

4. Hemorrhagic complication of thrombocytopenia and oral anticoagulant: Is there a role for recombinant activated factor VII ?. Intensive Care Med 28 (Suppl 2):S228, 2002

2010-04-07T21:52:00.000-07:00

Wednesday April 7, 2009

Scenario: 48 year old male, hemodialysis dependent, admitted with gastro-intestinal bleed. Last dialysis was 3 days ago. Patient received 4 units of pRBC and now hemodynamically stable. Nurse calls you as she felt that rhythm looks different on monitor. Patient is asymptomatic. Walking towards patient's bed what would be your top diagnosis ?

Answer: Hyperkalemia

Transfusion-associated hyperkalemia is a potential life threatening condition in patients with renal failure who have not been dialysed recently or with already elevated/borderline potassium level and should be followed closely.

2010-04-06T19:24:00.000-07:00

Tuesday April 6, 2010
Precedex (dexmedetomidine) for Cocaine overdose?

Objectives: The aim of this study was to determine whether cocaine’s sympathomimetic actions can be reversed by a potent centrally acting 2 adrenergic receptor (AR) agonist (dexmedetomidine).

Background: We recently showed that cocaine stimulates the human cardiovascular system primarily by acting in the brain to increase sympathetic nerve activity (SNA), the neural stimulus to norepinephrine release. Thus, SNA constitutes a putative new drug target to block cocaine’s adverse cardiovascular effects at their origin.

Methods: In 22 healthy cocaine-naïve humans, we measured skin SNA (microneurography) and skin blood flow (laser Doppler velocimetry) as well as heart rate and blood pressure before and after intranasal cocaine (2 mg/kg) alone and in combination with dexmedetomidine or saline.

Results: During intranasal cocaine alone, SNA increased by 2-fold and skin vascular resistance increased from 13.2 ± 2.3 to 20.1 ± 2.2 resistance units while mean arterial pressure increased by 14 ± 3 mm Hg and heart rate by 18 ± 3 beats/min (p less than 0.01). Dexmedetomidine abolished these increases, whereas intravenous saline was without effect. Dexmedetomidine was effective in blocking these sympathomimetic actions of cocaine even in all 7 subjects who were homozygous for the Del322-325 polymorphism in the 2C AR, a loss-of-function mutation that is highly enriched in blacks.

Conclusions: The data advance the novel hypothesis that central sympatholysis with dexmedetomidine constitutes a highly effective countermeasure for cocaine’s sympathomimetic actions on the human cardiovascular system, even in individuals carrying the 2CDel322-325 polymorphism.

Central Sympatholysis as a Novel Countermeasure for Cocaine-Induced Sympathetic Activation and Vasoconstriction in Humans - J Am Coll Cardiol, 2007; 50:626-633

2010-04-05T00:23:00.000-07:00

Monday April 5, 2010

Case: 54 year old female is admitted to ICU with pulmonary embolism. Patient is started on heparin and has been switched to coumadin (warfarin). Patient platelet count remained low and further workup confirmed HIT (Heparin induced thrombocytopenia). What should be administrated to patient along with initiation of either argatroban or lepirudin?

Answer: Vitamin K (10 mg po or 5 to 10 mg IV)

Warfarin should be postponed until substantial platelet recovery. If warfarin has already been started, vitamin K should be given to reverse the effect of warfarin. Warfarin should be avoided in acute HIT. Warfarin has been associated with worsening venous thrombosis, venous limb gangrene, and/or skin necrosis when used alone or in combination with ancrod in acute HIT. However, warfarin is appropriate for longer term anticoagulation in patients with HIT and thrombosis. Warfarin should be delayed until there is substantial resolution of the thrombocytopenia.

Treatment and Prevention of Heparin-Induced Thrombocytopenia - American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition) - CHEST June 2008 vol. 133 no. 6 suppl 340S-380S

2010-04-04T00:41:00.000-07:00

Sunday April 4, 2010
On heparin resistance and antithrombin deficiency

Case: 64 year old male is admitted to ICU with atrial fibrillation associated with RVR (rapid ventricular response). Patient has previous history of stroke. With rate control management patient is started on heparin for anticoagulation purpose. Heparin drip is now at 2400 units/hour but PTT is still not therapeutic, You suspect Anti-Thombin deficiency and indeed its level is low. Unfortunately pharmacist reports to you that there is an Anti-Thrombin shortage and will not be available. What is your other option?

Answer: Heparin principally exerts its anticoagulant effect by activating Antithromin (AT); the heparin-antithrombin (H-AT) complex then inactivates thrombin, activated factor X (fXa) and other activated clotting factors.

Heparin resistance is defined as the need for more than 35 000 Units in 24 h to prolong the activated partial thromboplastin time (APTT) into the therapeutic range. In contrast, during cardiac bypass procedures, the definition of heparin resistance is based on the activated clotting time (ACT), with at least one ACT less than 400 s after heparinization and/or the need for exogenous antithrombin administration. Heparin therapy produces a decrease in circulating antithrombin that is independent of the initial dose, is detectable after 1 day, and peaks after 2–4 days.

In above case your salvage is in use of a direct antithrombin inhibitor like bivalirudin. An important advantage of using bivalirudin instead of heparin is that there is no need to monitor or supplement ATIII levels for therapeutic effect.

2010-04-03T09:16:00.000-07:00

Saturday April 3, 2010

Case: In ACLS, dose for Vasopressin is 40 units IV x1. In desperate situations how quickly you can repeat it?

Answer: Though it is recommended every 20 minutes but in desperate situation you may use in 10 minutes.

Vasopressin is an adrenergic alternative to epinephrine, for promoting the return of spontaneous circulation after cardiac arrest. Vasopressin, a naturally occurring antidiuretic hormone, has powerful vasoconstrictor effects when used at doses much higher than normally found in the body. Its positive effects duplicate those of epinephrine, but with fewer or less-severe adverse effects. Vasopressin is administered intravenously as a one-time dose of 40 units. Compare its 10- to 20-minute half-life with the 3- to 5-minute half-life of epinephrine, and you'll see another reason why vasopressin is now finding favor in resuscitation efforts. However, if the patient doesn't respond to vasopressin, you can use epinephrine.

See this nice review: VASOPRESSIN AND SHOCK (Dr. Paul Forrest)

2010-04-02T00:56:00.000-07:00

Friday April 2, 2010

Case: 43 year old male with previous history of heart transplant found unresponsive and in asystole. Which regularly use 'code medicine' will not work on him?

Answer: Atropine

Patient has a transplanted heart and is denervated so atropine will not work. Immediate transcutaneous pacing (instead of atropine) should be placed.

2010-04-01T00:14:00.000-07:00

Thursday April 1, 2010
CXR diagnosis in Pulmonary Embolism
Looking for Westermark’s and Palla’s Signs together

Answer: Chest radiograph showing

Westermark’s sign - focal oligemia in the right lung (area between white arrowheads) and

Palla’s sign - a prominent right descending pulmonary artery (black arrow).

Westermark’s and Palla’s signs in combination are rare but, when seen, can help confirm diagnosis of pulmonary embolism.

Reference: Westermark’s and Palla’s Signs in Acute Pulmonary Embolism - Circulation. 2007;115:e211.http://circ.ahajournals.org/cgi/content/full/115/8/e211