Monday June 9, 2008
Evidence based medicine: Is it like changing wind

Commentary on new article published in Ann Intern Med 1

In the recent years medicine has focused on evidence based care. Critical care medicine has also seen the influx of lot of studies pointing in the same directions, ranging from activated protein C in severe sepsis and it’s down fall, to tight glycemic sugar control in sepsis and it’s down fall, to the yo-yo swinging data on use of steroids in sepsis. Only one thing was holding steadfast in this time of ever changing and contradictory data on different issues over time, we clearly saw one thing holding strong was that Intensivist model with 24/7 coverage in ICU saves life. Even the Leapfrog data from April 2008 favors the role of intensivist in improving survival and decreasing mortality by 40% in ICU and 30% decrease in hospital mortality, but lets check the data out which got published in Annals of Internal Medicine on the basis of Project IMPACT data ( a national database of ICU patients) 1. The project IMPACT database is a large administrative database originally developed by Society of Critical Care Medicine in 1996).

Design: Retrospective analysis of a large, prospectively collected database of critically ill patients in 123 ICUs in 100 US hospitals.

Patients: IMPACT project data base from 2000 to 2004 included 142,392 patients admitted to 123 ICUs. Of those 101,832 met criteria and qualified for analysis.

Measurements: Difference in hospital mortality between patients cared for entirely critical care physicians, and patients cared for entirely by non-critical care physicians.

An expanded Simplified Acute Physiology Score (SAPS) was used to adjust for severity of illness, and propensity score was used to adjust for difference in the probability of selective referral to critical care physicians.

Results: After adjustment for severity of illness and propensity score, hospital mortality rates were higher for patients who received care by Critical Care Management than for those who did not. Patient taken care by intensivist were sicker. They also end up in getting more procedures.


Limitations of the study:

1. Project Impact measures only ICU and hospital mortality. No information was collected after they left the hospital.
2. Process of identifying and management of patients has limitations.
3. Data elements for analysis are limited to those available in IMPACT database. Presence or absence of protocols, order sets, the length of experience of nursing staff, nurse patient ratio, how many group of critical care physicians, hand off procedures not known.
4. Percentage of patients managed by full time intensivist cannot be identified in IMPACT database, therefore cannot assess the benefit of full time, onsite management by ICU physicians.
   

our editors' Conclusion: Further well designed prospective study should be undertaken.

Reference: click to get abstract

Levy MM, Rapoport J, Lemeshow S, Chalfin DB, Phillips G, Danis M. Association between critical care physician management and patient mortality in the intensive care unit.

Ann Intern Med 2008; 148:801-809

Sunday June 8, 2008
Salmonella (Saintpaul strain) illnesses spread to 16 states

Salmonella food poisoning first linked to uncooked tomatoes has spread to 16 states, federal health officials said Saturday. Click to read more deatils http://www.cdc.gov/salmonella/saintpaul/


See here detailed ppt. presentation Salmonella (Seminar in Nucleic Acids-Spring 2004)

Read precise review article Salmonella Infection (emedicine.com)

Saturday June 7, 2008
Interesting study ! - Potentially helpful for the ICU

Methylnaltrexone(Relistor) for Opioid-Induced Constipation

Background: Constipation is a distressing side effect of opioid treatment. As a quaternary amine, methylnaltrexone, a µ-opioid–receptor antagonist, has restricted ability to cross the blood–brain barrier. The safety and efficacy of subcutaneous methylnaltrexone for treating opioid-induced constipation in patients with advanced illness is investigated.

Methods: A total of 133 patients who had received opioids for 2 or more weeks and who had received stable doses of opioids and laxatives for 3 or more days without relief of opioid-induced constipation were randomly assigned to receive

• subcutaneous methylnaltrexone (at a dose of 0.15 mg per kilogram of body weight) or
• placebo every other day for 2 weeks

Coprimary outcomes: laxation (defecation) within 4 hours after the first dose of the study drug and laxation within 4 hours after two or more of the first four doses.

Results

• In the methylnaltrexone group, 48% of patients had laxation within 4 hours after the first study dose, as compared with 15% in the placebo group, and
  52% had laxation without the use of a rescue laxative within 4 hours after two or more of the first four doses, as compared with 8% in the placebo group (P<0.001>
• The response rate remained consistent throughout the extension trial.
• The median time to laxation was significantly shorter in the methylnaltrexone group than in the placebo group.
• Evidence of withdrawal mediated by central nervous system opioid receptors or changes in pain scores was not observed.
• Abdominal pain and flatulence were the most common adverse events.

Conclusions: Subcutaneous methylnaltrexone rapidly induced laxation in patients with advanced illness and opioid-induced constipation. Treatment did not appear to affect central analgesia or precipitate opioid withdrawal.


Related previous pearl: Oral Narcan for opioid induced constipation !



References: click to get abstract/article

1. Methylnaltrexone for Opioid-Induced Constipation in Advanced Illness- The New England Journal of Medicine, Volume 358:2332-2343, May 29 2008, Number 22

Friday June 6, 2008
At last something favouring femoral access ! - Cathedia Study

A recent study (Cathedia Study) published in favour of femoral access 1. Study was a multicenter study of 750 patients from a network of 9 tertiary care university medical centers and 3 general hospitals in France conducted between May 2004 and May 2007.

Context: Based on concerns about the risk of infection, the jugular site is often preferred over the femoral site for short term dialysis vascular access.

Objective: To determine whether jugular catheterization decreases the risk of nosocomial complications compared with femoral catheterization.

Design: The severely ill, bed-bound adults had a body mass index (BMI) of less than 45 and required a first catheter insertion for renal replacement therapy.

Intervention: Patients were randomized to receive jugular or femoral vein catheterization by operators experienced in placement at both sites.

End-point: Rates of infectious complications, defined as

1. Catheter colonization on removal (primary end point), and
2. Catheter-related bloodstream infection

Patient and catheter characteristics, including duration of catheterization, were similar in both groups.


Results:

• More hematomas occurred in the jugular group than in the femoral group (13/366 patients [3.6%] vs 4/370 patients [1.1%]).
• The risk of catheter colonization at removal did not differ significantly between the femoral and jugular groups (incidence of 40.8 vs 35.7 per 1000 catheter-days).
• A prespecified subgroup analysis demonstrated significant qualitative heterogeneity by BMI. Jugular catheterization significantly increased incidence of catheter colonization vs femoral catheterization (45.4 vs 23.7 per 1000 catheter-days) in the lowest tercile (BMI less than 24.2), whereas jugular catheterization significantly decreased this incidence (24.5 vs 50.9 per 1000 catheter-days) in the highest tercile (BMI>28.4)
• The rate of catheter-related bloodstream infection was similar in both groups (2.3 vs 1.5 per 1000 catheter-days)

Conclusion: Jugular venous catheterization access does not appear to reduce the risk of infection compared with femoral access, except among adults with a high BMI, and may have a higher risk of hematoma.



References: click to get abstract/article

1. Femoral vs Jugular Venous Catheterization and Risk of Nosocomial Events in Adults Requiring Acute Renal Replacement Therapy - A Randomized Controlled Trial , JAMA. 2008;299(20):2413-2422.

Thursday June 5, 2008


Q: How many units of platelets are required to avoid possible bleeding due to 300 mg dose of Plavix (clopidogrel)?


Answer: 10 units

According to one recent work 1, pre-operative transfusion of 10 platelet concentrate units after a 300-mg clopidogrel loading or 12.5 units after a 600 mg loading may adequately reverse clopidogrel-induced platelet disaggregation to facilitate postoperative hemostasis. An additional 2.5 units fully normalized platelet function. Roughly, each unit of platelet concentrate would incrementally increase platelet count by 10, 000 uL



Editors' note: Limitation of study - the study was performed under in vitro conditions and there is a lack of information regarding the correlation with in vivo clinical outcomes, which is acknowledged by authors.


References: click to get abstract/article

1. Normalization of platelet reactivity in clopidogrel-treated subjects - Journal of Thrombosis and Haemostasis, 5: 82–90

Wednesday June 4, 2008


Case: 58 year old female admitted to ICU with exacerbation of Asthma. Patient is on coumadin 5 mg per day due to previous DVT, which was continued in ICU. INR on admission was therapeutic with 2.6. Patient was intubated and started on IV steroid along with antibiotic (Ceftriazone) and other home meds. Standard ICU protocols for GI prophylaxis with esomeprazole, blood sugar control, enteral nutrion and head of bed elevation were also initiated. progressively INR continues to rise and on 6th ICU day, GI bleed developed. Which medicine may have interacted with coumadin to increase INR and subsequently GI bleed?


Answer: Esomeprazole (proton pump inhibitor)

Concomitant use of warfarin (coumadin) and esomeprazole therapy may increases INR, and supratherapeutic prothrombin time may lead to abnormal bleeding and even death. Patients treated with proton pump inhibitors and warfarin concomitantly may need to be monitored for increases in INR and prothrombin time.


References: click to get abstract/article

1. Nexium - Rxlist.com

Tuesday June 3, 2008
Time lag between Linezolid and Thrombocytopenia

Thrombocytopenia could be multifactorial in ICU. One of the relative new cause is Linezolid (Zyvox). But thrombocytopenia with Zyvox usually doesn't occur upto 2 weeks with the initiation of treatment and could help in ruling out atleast one reason. Relatively overall its mild, reversible and due to myelosuppression. there is no evidence for anti-platelet or interference with platelet function.


References: click to get abstract/article

1. Hematologic Effects of Linezolid: Summary of Clinical Experience - Antimicrobial Agents and Chemotherapy, August 2002, p. 2723-2726, Vol. 46, No. 8
2. Linezolid and reversible myelosuppression. - JAMA 285:1291
3. Safety, efficacy and pharmacokinetics of linezolid for treatment of resistant Gram-positive infections in cancer patients with neutropenia - Annals of Oncology 14:795-801, 2003

Monday June 2, 2008

Q; Patient with which poisoning presents with garlic odor?

A: Organophosphate poisoning.

Sunday June 1, 2008

Q; Name atleast 7 non-septic conditions which can cause low SVR (systemic vascular resistance) ?

1. Hemorrhagic (or necrotizing) Pancreatitis

2. Cirrhosis

3. Adrenal insufficiency

4. Head Injury ( initially increase SVR followed with low SVR)

5. Bactrim (TMP-SMX) in AIDS patient

6. Within 6 hours of postcardiopulmonary bypass (vasoplegic syndrome)

7. Spinal cord Injury above T6 (inhibited vagal tone)



Reference: click to get abstract/article

Low systemic vascular resistance: differential diagnosis and outcome - Critical Care 1999, 3:71-77