Saturday, December 31, 2005

ss

Saturday December 31, 2005
SEROTONIN SYNDROME

Serotonin syndrome is a potentially lethal condition caused by overstimulation of central and peripheral serotonin receptors. SSRI, MAOI and other antidepressants are the biggest culprits. (Everybody seems to be on some type of antidepressant these days!). Mild cases of serotonin syndrome may present with nausea, vomiting, flushing, and diaphoresis. Severe cases may present with hyperreflexia, myoclonus, muscular rigidity, hyperthermia, and autonomic instability. Diagnosis is clinical and no lab tests are available.


Treatment include discontinuation of all serotonergic medications. The initial treatment of serotonin syndrome is with benzodiazepines and cyproheptadine. Cyproheptadine (Periactin) appears to be the most effective antiserotonergic agent in humans. The initial dose is 4 - 8 mg PO. This dose can be repeated in 2 hrs if no response is noted to the initial dose. Periactin therapy should be discontinued if no response is noted after 16 mg has been administered. Patients who respond to cyproheptadine are usually given 4 mg every 6 h for 48 h to prevent recurrences. Dantrolene (0.5-2.5 mg/kg IV every 6 h, maximum 10 mg/kg per 24 h or 50 to 100 mg bid PO) is a nonspecific muscle relaxant that is used occasionally in serotonin syndrome, presenting with hyperthermia.


See brief review on Serotonin syndrome
here from McGill University, Montreal. CMAJ • May 27, 2003; 168 (11) followed with letter Serotonin syndrome: not a benign toxidrome CMAJ • September 16, 2003; 169 (6)

References: Click to get abstract or article
1.
Serotonin syndrome. A clinical update - Mills KC - Crit Care Clin. 1997 Oct;13(4):763-83. via pubmed
2.
Treatment of the serotonin syndrome with cyproheptadine - J Emerg Med., 1998 Jul-Aug;16(4):615-9. via pubmed
3.
The Serotonin Syndrome - NEJM, March 2005 Volume 352:1112-1120

Friday, December 30, 2005

Friday December 30, 2005
Estimating Burn area

There are 3 ways to estimate %TBSA burn (% Total Body Surface Area Burn).

1. "rule of nine" remains universally accepted tool to calculate %TBSA burn. Click
here to see the diagram.1

2. Lund-Browder chart is more accurate method of calculating %TBSA Burn. Click
here to see the chart 2

3. Recently computer based softwares have been introduced with color coded calculation and instant resuscitation guide. See sample Surface Area Graphic Evaluation software method
here. 3

See most comprehensive Burn management guide at

" www.burnsurgery.org "


References: Click to get abstract or article
1.
Initial management of a major burn: II—assessment and resuscitation - BMJ 2004 ; 329:101-103
2.
Total Burn Care - totalburncare.com
3.
Surface Area Graphic Evaluation

Thursday, December 29, 2005

Thursday December 29, 2005
ReoPro and Integrilin (Glycoprotein 2b/3a Receptor Inhibitors)


Although our cardiology colleauges mostly take care of intravenous antiplatelet therapy in acute situations but atleast to be aware of basic differences between 2 widely used iv antiplatelet agents.

ReoPro (abciximab): is a large molecule agent and binds irreversibly to Gp2b/3a receptors of platelets and so clinical effect lasts for 7 to 10 days and for same reason needs platelet transfusion in case of bleeding. ReoPro is usually given in STEMI ( ST elevated - Myocardial infarction). It may cause severe thrombocytopenia within hours of infusion.

Integrilin (eptifibatide): is a small molecule and binds reversibly to Gp2b/3a receptors of platelets and so clinical effect lasts for only 4 to 6 hours. Platelet transfusion is not required and should be avoided in case of bleeding as it may inhibits new platelet formation. Integrilin is usually given in NSTE-ACS (Non ST elevation - acute coronary syndrome). It is 50% cleared by kidney. Also dosing is weight dependent. Dosing chart is available in package insert. 4

Avoid unnecessary IV or IM sticks while patient on Gp2b/3a infusion.

References: Click to get abstract or article

1.
ABCIXIMAB - Stanford University Interventional Cardiology
2.
EPTIFIBATIDE - Stanford University Interventional Cardiology
3.
A Clinical Trial of Abciximab in Elective Percutaneous Coronary Intervention after Pretreatment with Clopidogrel - NEJM, Jan. 2004 Volume 350:232-238
4.
Integrilin - package insert
5.
Abciximab as Adjunctive Therapy to Reperfusion in Acute ST-Segment Elevation Myocardial Infarction - JAMA Vol. 293 No. 14, April 13, 2005

Tuesday, December 27, 2005

Wednesday December 28, 2005
Is confirmatory chest-x-ray always necessary?


It is a standard of practice to have followup chest-x-ray following endotracheal intubation and central venous catheter insertion. But do we always absolutely need it ?. See these 2 interesting studies both comprised of 100 patients.


For endotracheal tube: Prospective study of 101 patients done at Cooper Hospital, Camden, NJ showed that the incidence of acutely significant malpositions of endotracheal tube, when performed by experienced critical care personnel, were rare (one out of 101 intubations), and may be followed by routine, rather than 'stat' chest radiographs.1

For central venous catheter (IJ): Prospective study of 100 patients done at Lenox Hill Hospital, New York showed that 98 catheters were in accurate position after uncomplicated insertion of a Triple-Lumen Catheter in the Right internal jugular vein with anterior approach and concluded that it is safe to omit the routine chest radiograph after uncomplicated insertion of a TLC and IV treatment can be initiated early. 2 (We found atleast one study in literature arguing against this work. Study of 107 patients from NIH showed 14% incidence of malpositions, and conclusion was: Chest radiographs are necessary to ensure correct internal jugular catheter position).3

References: Click to get abstract or article

1.
Utility of postintubation chest radiographs in the intensive care unit - Critical Care 2000, 4:50-53
2.
Is Chest Radiography Necessary After Uncomplicated Insertion of a Triple-Lumen Catheter in the Right Internal Jugular Vein, Using the Anterior Approach?* - Chest. 2005;127:220-223
3.
Cannulation of the internal jugular vein: Is postprocedural chest radiography always necessary? - Critical Care Medicine: Volume 27(9) September 1999 pp 1819-1823
4. Value of postprocedural chest radiographs in the adult intensive care unit - Crit Care Med 1992; 20:1513-1518

ve

Tuesday December 27, 2005
Vasoconstrictor extravasation


Antidote for vasoconstrictor extravasation in skin and tissues (dopamine, epinephrine, or norepinephrine) is PHENTOLAMINE. Infiltrate 5-15 mg of PHENTOLAMINE in 10 ml of normal saline into the area of extravasation as soon as possible. Treatment may be applied and effective up to 12 hours post extravasation of vasoconstrictor. Keep yourself ready for fluid bolus post treatment. Mechanism of action: Phentolamine is a nonspecific alpha-adrenergic blocking agent which inhibits vasoconstriction and allow improved blood circulation through the affected area.


References: Click to get abstract or article

1.
Drug Monographs - Phentolamine - lhsc.on.ca
2.
pediatric pharmacotherapy / intravenous extravasations-
3.
Treating Extravasation Injuries - extravasation.org
4.
The use of phentolamine in the prevention of dopamine-induced tissue extravasation - J Crit Care 1998 Mar;13(1):13-20

Monday, December 26, 2005

ivi

Monday December 26, 2005
Intravenous(IV) Iron

There are 3 forms of IV Iron available in USA. 1. Iron dextran, 2. Iron sucrose and 3. Sodium ferric gluconate. Iron dextran definitely requires "test dose" in the presence of physician with epinephrine at bedside. About 1 out of 200 patients develops life-threatening anaphylaxis. In remaining 2 forms also, test dose is advisible. Watch time after 'test dose' is about one hour. IM or SQ administration of Iron is not standard of practice.

Also dose should be calculated irrespective of form of iron use.

Iron deficiency anemia: Various formulae have been described (see references) but most widely use is

"Total" amount of iron in mg = { 0.3 x abw (lbs) x 100 (14.8 - present Hgb)] / 14.8

abw = actual body weight 14.8 is constant as ideal Hb

Calculate dose at online calculator (see Ref. 2).

In blood loss:

"Total" iron dose (in mg) = Blood loss (ml) x present Hematocrit.

The total Fe can be given as a single dose in .5 L NS over 6 hours or in divided doses over few days.

References: Click to get abstract or article
1.
Administration of intravenous iron dextran - http://sickle.bwh.harvard.edu/
2. Iron Dextran Calculator - globalrph.com
3. parental iron supplement - thedrugmonitor.com

Saturday, December 24, 2005

Sunday December 25, 2005
Christmas Quiz Question

Q: What's the difference between fellow and attending ?
A: Fellow knows "what to do" and attending knows "what not to do"

Friday, December 23, 2005

Saturday December 24, 2005
Is SLEDD better than CVVHD in ICU patients ?

With advent of Continuous Veno-Venous Hemodialysis (CVVHD) we found some relief for our hemodynamically unstable patients with acute renal failure but CVVHD has its own cons with need of more trained staffing, cost, time, anticoagulation issues, nutrition issues etc. To find a path between two modalities (conventional HD and CVVHD), new literature is suggesting that slow extended daily hemodialysis (SLEDD) may be more or atleast equally effective. Click on Reference 1 to see small study of 20 patients comparing SLEDD and CVVHD. Nephrol Dial Transplant (2004) also found SLEDD as an effective alternative. As concluded in Intensive Care Nephrology 2000 that "..advantages (of CRRT) can, however, also be obtained with SLEDD. In addition, SLEDD is less expensive than CRRT and does not continuously immobilize the patient, leaving time open for other activities..".3 Or probably the skills and the experience of the physicians and nurses who perform dialysis are more important than the applied dialysis modalities. 4


References: Click to get articles/abstract
1.
Comparison of slow extended daily hemodialysis (SLEDD) to continuous renal replacement therapy in acute renal failure patients in the intensive care unit (ICU) - Abstract no: 18, Kidney International Society Abstracts.
2.
Sustained low-efficiency daily diafiltration (SLEDD-f) for critically ill patients requiring renal replacement therapy: towards an adequate therapy - Nephrol Dial Transplant (2004) 19: 877-884
3.
What Is the Renal Replacement Method of First Choice for Intensive Care Patients? - J Am Soc Nephrol 12:S40-S43, 2001
4.
Dialysing the patient with acute renal failure in the ICU: the emperor's clothes? - Nephrol Dial Transplant (1999) 14: 2570-25735. Daily Hemodialysis and the Outcome of Acute Renal Failure - NEJM, Jan. 2002, Volume 346:305-310

Thursday, December 22, 2005

Friday December 23, 2005
Scleroderma Renal Crisis (SRC)


Scleroderma Renal Crisis is one of the few rheumatological emergency where early diagnosis and treatment can make big difference in outcome. Wrong diagnosis may lead to wrong management pathway and eventually to very high mortality. SRC is heralded with hypertensive crisis associated with acute renal failure but the pearl is to avoid IV Labetolol or nitroprusside and gradually decrease blood pressure with PO angiotensin-converting enzyme (ACE) inhibitors. calcium channel blockers may help. Renal dialysis is a last resort. Another important differential diagnosis is from SLE (renal). 5 It has been suggested that use of steroids is associated with onset of scleroderma renal crisis.

See this precise review article on SRC
here from Department of Rheumatology and Internal Diseases, Medical University in Białystok, Poland. (2005)

References: Click to get articles/abstract
1.
What Is Scleroderma Renal Crisis and How Is it Managed? via medscape.com with free registration
2.
Systemic Sclerosis With Renal Crisis and Pulmonary Hypertension - stanford.edu
3.
Long-Term Outcomes of Scleroderma Renal Crisis - 17 October 2000 Volume 133 Issue 8 Pages 600-603 - annals
4. Scleroderma Renal Crisis: The Sword of Damocles. - JCR: J. of Clinical Rheum. 10(5):234-235, October 2004.
5.
Rheumatologic Renal Disease: SLE vs. Scleroderma - ucsf.edu

Wednesday, December 21, 2005

Thursday December 22, 2005
Whats new on Horizon - blood substitutes


Being an intensivist it is imperative to keep up with all new "stuff" on horizon. In this regard blood substitutes will soon actually be knocking on the door.
Hemopure, a Bovine derived blood substitute, has been approved for use in adult patients in South Africa. Polyheme, a human derived blood substitute is already in Phase III trial in united states for hemorrhagic shock following traumatic injuries. These are solutions of chemically modified human or bovine hemoglobin which restores lost blood volume and can be given as rapid, massive infusion. One unit is equal to one unit of pRBC and can be given wide open.

Advantages: Does not require typing or cross-matching before infusion and so far found not to cause transfusion reactions. Shelf life of over 12 months (ciruclation time is 1-2 days) and does not require refrigeration. Bovine based Hemopure has been said acceptable for use in Jehovah's Witnesses (?).

Disadvantages: No evidence based data available yet. Concerns raised re. Mad cow disease in bovine based Hemopure !.

Read interesting critical commentary on above products
here from Randy Dotinga at wired.com

References: Click to get abstract/article
1.
Safety and Efficacy of PolyHeme(R) in Hemorrhagic Shock Following Traumatic Injuries Beginning in the Pre-Hospital Setting - clinicaltrials.gov
2.
Watchtower Approves HemoPure for Jehovah's Witnesses - ajwrb.org
3.
Effect of Hemopure® on Prothrombin Time and Activated Partial Thromboplastin Time on Seven Coagulation Analyzers, - Clinical Chemistry. 1997;43:1792
4.
PolyHeme - American College of Surgeons at facs.org

Tuesday, December 20, 2005

Wednesday December 21, 2005
Vancomycin dosing in CRRT


Vancomycin dosing is different in CRRT (Continuous Renal Replacement Therapy) from IHD (Intermittent HemoDialysis) as vancomycin is effectively removed during CRRT. Vancomycin is 14K daltons and CRRT filter removes upto 20K daltons size molecules. Frequent monitoring of Vancomycin level is required. Different intervals has been described from 24 to 48 hours. Most agree on 10 mg/kg every 24 hours. If patient is on CVVHDF instead of CVVHD than it might go upto 15 mg/kg per day. Ultimate goal is to keep vancomycin trough atleast between 10 - 15 mcg/ml and should not fall below 8 mcg/ml.

Related: See nice power point presentation on CRRT from Gregory M. Susla Pharm.D (Bayer)
here .

References: Click to get abstract/article
1.
Vancomycin dosing and monitoring - Division of Infectious Diseases, Department of Medicine, Columbia University Medical Center (CUMC), columbia.edu
2. Antimicrobial dosing in continuous renal replacement therapy - with free registration at
http://infectiousdiseasenews.com
3. CVVH Initial Drug Dosing Guidelines - from www.thedrugmonitor.com

Monday, December 19, 2005

Tuesday December 20, 2005
BNP or Pro-BNP ?


Although BNP and NT-proBNP are breakdown products of same parent peptide but in laboratory BNP and NT-proBNP are 2 different tests with 2 different ranges of normal, designed for same reason. Psychologically we are so prone to use BNP that we may have NT-proBNP value in our hand but read it as BNP. There is no conversion formula. NT-proBNP is 2.5 times heavier peptide than BNP (76 amino acids vs 32 amino acids) with 3- 6 times longer half life (120 minutes vs 20 minutes). NT-proBNP get solely excreted via kidney but BNP gets only partially excreted via Kidney. In short NT-proBNP of 400 may means nothing but may be significant if its BNP. Please check: Is it BNP or NT-proBNP ?. It may require different clinical approach though for same clinical problem. Both tests have very good negative predictive value for LV-dysfunction.

Do you know which assay your laboratory use?

References: Click to get abstract/article
1.
EDUCATIONAL COMMENTARY - BNP - American Proficiency Institute – 2002 3rd Test Event
2.
Using BNP to diagnose, manage, and treat heart failure - CLEVELAND CLINIC JOURNAL OF MEDICINE VOLUME 70 • NUMBER 4, APRIL 20033. NT-ProBNP - referencelab.clevelandclinic.org May 2004
4.
Application of NT-proBNP as a Diagnostic Marker of Cardiac Disease - available free at medscape with CME with free registration at medscape.com
5. NT-proBNP test results comparable to those of BNP blood test in patients with kidney disease - rxpgnews.com

Sunday, December 18, 2005

rdn

Monday December 19, 2005
Renal Dose Norepinephrine !


This interesting term was coined by Dr. Marik in August 2004 chest journal with final comment: "...In the volume-replete patient, norepinephrine is the vasopressor of choice. Norepinephrine in clinically relevant doses is a friend of the kidney and not a foe" *, while commenting on the study in the same issue from Albanèse and coll. that found that in septic patients norepinephrine infusion reestablished urine flow, with a decrease in serum creatinine levels and an increase in creatinine clearance rate after 24 hours. Although Guidelines published in Critical Care Medicine - November 2004 on "Vasopressor and inotropic support in septic shock: An evidence-based review" still recommends that: "Either norepinephrine or dopamine is the first-choice vasopressor agent to correct hypotension in septic shock." but overall trend is going in favour of norepinephrine.

*From Noradrenaline and the kidney: friends or foes? - Critical Care 2001, 5:294-298

References: Click to get abstract/article

1.
Renal Dose Norepinephrine! - Chest. 2004;126:335-337
2.
Renal Effects of Norepinephrine in Septic and Nonseptic Patients - Chest. 2004;126:534-539
3.
Noradrenaline and the kidney: friends or foes? - Crit Care 2001, 5:294-298
4.
Vasopressor and inotropic support in septic shock: An evidence-based review. - Critical Care Medicine. 32(11) Supplement:S455-S465, November 2004

Saturday, December 17, 2005

Sunday December 18, 2005
Enoxaparin (Lovenox) dose in obesity


There is no standard guidelines so far available for
Lovenox dose in obesity (particularly beyond 150 kg). Best way is to manage it through anti-factor Xa levels (The target therapeutic range is 0.6-1.0 IU/ml - draw 4 hours after 3rd dose). But many hospitals don't have anti-factor Xa levels available or turn around time is too long. One crude way is to dose per "adjusted body weight".

ABW = IBW + 0.4 [TBW – IBW]


ABW = Adjusted body weight
IBW = Ideal body weight
TBW = Total body weight


* Obesity is defined as a BMI >30kg/m2


Reference: Click to get abstract/article
1.
Drug Use Criteria for Low Molecular Weight Heparins and Fondaparinux - Source visn21.med.va.gov

Friday, December 16, 2005

Saturday December 17, 2005
What is SHARF score ?


SHARF stands for "Stuivenberg Hospital Acute Renal Failure" (from Stuivenberg General Hospital, Antwerp, Belgium). This is a prognostic scoring system for hospital mortality of individual patients with acute renal failure - ARF. It is considered to be very predictable.

Score is calculated at the time of diagnosis of ARF (SHARF T0) and the other at 48 hours later (SHARF T48). It is a complicated formula with age, albumin, prothrombin time, ventilator support, heart failure. In modified formula sepsis, hypotension and bilirubin has also been added. To compound it you have to compute age in decades, albumin and Prothrombin time according to category table and other parameters as present or absent. Probably due to its complication it never get popular. Our objective is to make intensivists be aware of its presence in literature.

Click to see
formulae and category table.


References: Click to get abstract/article
1.
Prognostic value of a new scoring system for hospital mortality in acute renal failure - via pubmed - Clin Nephrol. 2000 Jan;53(1):10-7.
2.
Re-evaluation and modification of the Stuivenberg Hospital Acute Renal Failure (SHARF) scoring system for the prognosis of acute renal failure: an independent multicentre, prospective study - Nephrology Dialysis Transplantation 2004 19(9):2282-2288
3.
Interim results of the SHARF4 study: outcome of acute renal failure with different treatment modalities - Critical Care 2004, 8(Suppl 1):P153

Thursday, December 15, 2005

Friday December 16, 2005
Quick bedside test for Methemoglobinemia

A quick bedside test to strongly suspect (MetHb) Methemoglobinemia is to bubble 100% oxygen in tube with patient's dark blood. No change in Color strongly predicts Methemoglobinemia. If blood turns red on exposure to oxygen, cause is probably cardiopulmonary disease. (Same test can be done with 2 drops of patient's blood on white filter paper and exposing it to atmospheric oxygen. Change in color rule out Methemoglobinemia). Although Co-oximetry is an accurate method for measuring Methemoglobinemia, not all machines can (only newer versions can) differentiate it from another rare disorder sulfhemoglobinemia.


References:
1.
A case of sulfhemoglobinemia and emergency measurement of sulfhemoglobin with an OSM3 CO-oximeter - Clinical Chemistry 43: 162-166, 1997;
2.
Pitfalls in Discriminating Sulfhemoglobin from Methemoglobin - Clinical Chemistry 43: 1098-1099, 1997;
3.
Methemoglobinemia - please register free at emedicine.com

Wednesday, December 14, 2005

fr

Thursday December 15, 2005
"Five Rights"

It is important that we continue to vibrate "Five Rights" message down the line to house staff and other staff involved in Critical Care to minimize medication errors.

1. Right Patient.
2. Right Drug.
3. Right Time.
4. Right Dose.
5. Right Route.

(Also mentioned somewhere addendum with 6. Right Documentation 7. Right Indication 8. Right to Refuse).

But read this interesting constructive critique from Matthew Grissing RPh, a medication safety analyst with the Institute for Safe Medication Practices to understand what else need to be done beside "Five Rights". - Reference: P & T Vol. 27 No. 10, October 2000.

Tuesday, December 13, 2005

Wednesday December 14, 2005
7 pearls re. Milrinone

1. Milrinone need to be protected from light and if drip is discoloured or precipitation is visible (light effect) - it may be an ineffective bag.

2. Dose need to be adjusted according to renal funtion. (unfortunately often get ignored in ICUs)

3. Milrinone induced hypotension is more responsive to low dose vasopressin (.01 - .04 units/min).

4. Initial bolus should be given atleast over 10 minutes.

5. Milrinone is drug of choice over Dobutamine in cardiogenic pulmonary edema.

6. Limited known is the direct beneficial role of milrinone in severe cardiac depression from calcium channel blocker overdose. (Caution about hypotension!)

7. Pre-emptive perioperative infusion of milrinone in off-pump coronary artery bypass surgery showed to improve cardiac performance when compared to normal saline.


References: Click to get abstract/article

1.
Comparative efficacy of short-term intravenous infusions of milrinone and dobutamine in acute congestive heart failure following acute myocardial infarction. Milrinone-Dobutamine Study Group - via pubmed Clin Cardiol. 1996 Jan;19(1):21-30

2. Vasopressin as an alternative to norepinephrine in the treatment of milrinone-induced hypotension - Critical Care Medicine: Volume 28(1) January 2000 pp 249-252

3. Efficacy of pre-emptive milrinone in off-pump coronary artery bypass surgery: comparison between patients with a low and normal pre-graft cardiac index - Eur J Cardiothorac Surg 2004;26:687-693
Tuesday December 13, 2005
Oral care in ICU


Oral care is an integral part of ICU care. One recent study showed decrease in ventilator associated pneumonia (VAP) rate from 5.6 VAPs/1000 ventilator days to 2.0 VAPs/1000 ventilator days. Due to significance, one clinical trial is comparing a program of meticulous oral care using oral assessments taught by a dentist and dental hygienist with the standard nursing care typically given in ICUs. A recent study from Dutch investigators showed that 2% chlorhexidine every six hours by swabbing it onto the buccal cavity decreases VAP significantly and is way more effective than traditional .12% chlorhexidine .

See one sample
ORAL CARE FOR INTUBATED PATIENTS protocol - from London Health Sciences Centre, Canada.

References:

1.
You can make a difference in 5 minutes - Evidence-Based Nursing 2004; 7:102-103
2.
Oral Care to Reduce Mouth and Throat Infections in Critically Ill Patients - clinicaltrials.gov
3.
Oral Care Interventions in Critical Care: Frequency and Documentation - American Journal of Critical Care. 2003;12: 113-118
4.
Chlorhexidine 2% Preparation Reduces the Incidence of Ventilator-Associated Pneumonia - 44th Interscience Conference on Antimicrobial Agents and Chemotherapy: Abstract 3717. Presented Oct. 31, 2004 - via medscape.com with free registration)

Sunday, December 11, 2005

Monday December 12, 2005
Continuous intravascular blood gas monitoring

As ICUs are getting more and more tech-savy, intensivists have also been added with extra responsibility to know the evidence based status of different machines / technologies. In this term, one fast emerging technique is continuous intravascular blood gas monitoring. Our literature search (major work so far done in pediatric critical care) showed favourable approach to this technology despite reports of inaccurate measurement of PO2. As technique is very young, no data is available on cost effectiveness. But in adult patients overall its a good peri-operative and immediate post-operative tool particularly in cardiothoracic patients (transplant, one lung ventilation etc). Also, its a better replacement in extremely unstable patients requiring multiple ABGs such as refractory septic shock, ARDS, severe COPD and trauma patients.


Related: Click here to read good review article with links to all major studies re. continuous intravascular blood gas monitoring. British Journal of Anaesthesia, 2003, Vol. 91, No. 3 397-407

Saturday, December 10, 2005

Sunday December 11, 2005
Ice test - Poor man's test for Myasthenia Gravis

Most of the Myasthenia patients along with other symptoms of weakness usually exhibits ptosis. While at bedside place an ice cube over eye lids for 2 minutes. Cooling improves neuromuscular transmission. Resolution of ptosis with cooling is a positive test for Myasthenia Gravis and reported upto 80% reliable to diagnose ocular myasthenia.


Related: Click here to read good review article on Myasthenia Gravis from Dr. Milind J. Kothari. The Journal of the American Osteopathic Association. Vol 104 • No 9 • Sept. 2004 • 377-384

Friday, December 09, 2005

Saturday December 10, 2005
Vasopressin .07 units/min ?

There has been a lot of enthusiasm about using vasopressin as vasopressor earlier than later in septic shock patients due to initial encouraging literature with dose of .01-.04 units/min. But anecdotally it has been tried upto .07 units/min to enhance the effect. We looked into the literature in this regard and found atleast one study where dose beyond .04 units/min was reported to be associated with higher adverse effects. Study from Vancouver, Canada looked into 50 patients with mean APACHE II score of 27. Baseline data at 0 hour was compared to 4, 24 and 48 hours of vasopressin infusion. Though most parameters improved there were six cardiac arrests; all but one occurred at a vasopressin dose of 0.05 units/min or more. The final conclusion was "Doses higher than 0.04 units/min were not associated with increased effectiveness and may have been associated with higher adverse effects."



References:

The effects of vasopressin on hemodynamics and renal function in severe septic shock: a case series - Intensive Care Med 2001 Aug;27(8):1416-21

Thursday, December 08, 2005

Friday December 9, 2005
7 Pearls re. Myxedema Coma

Myxedema Coma is a medical emergency but being an intensivist 7 pearls are worth remembering:

Myxedema Coma is a clinical diagnosis and treatment should not be delayed for laboratory confirmation.

Even if enteral route is available - IV Thyroid hormone (T4 or T3) replacement is needed as GI absorption is unreliable.

T4 is preferable if underlying cadiac co-morbidity is suspected.

Simultaneously steroids should also be started after random cortisol level is drawn.

Adding prophylactic antibiotics is not a bad idea.

Hypotension is not due to volume depletion so avoid aggressive fluid resuscitation.

Thermometers that can record below 90°F (32.2 C) is preferable.

Read intereating case study with discussion and treatment options on Myxedema Crisis
here from Israeli Journal of Emergency Medicine – in pdf - (Vol. 5, No. 4 Oct 2005)

Wednesday, December 07, 2005

pivde

Thursday December 8, 2005
Preventing intra-venous (IV) drip errors

Many studies have shown so far that errors in administration of intravenous drugs remain high and actually even higher in ICUs. Standard protocols need to be instituted for sure at bedside to prevent errors in IV administrations but anecdotal reports shows that 2 quick interventions can decrease the rate of error significantly.

1. Vasoactive drugs be infused through a dedicated site and using other separate IV site for other infusions.

2. Triple sticker labeling of IV drips (at/near IV bag, pump and infusion sites).

References: Click here to get article
1.
Ethnographic study of incidence and severity of intravenous drug errors - BMJ 2003;326:684 (29 March)
2.
Preventable adverse drug events in hospitalized patients: a comparative study of intensive care and general care units - Crit Care Med 1997 Aug;25(8):1289-97.

Tuesday, December 06, 2005

Wednesday December 7, 2005
Re. Nesiritide (Netrecor)

Netrecor (nesiritide) not only walked into our hospitals for "exacerbation of CHF" but even in out-patient clinics for "tune-up of CHF" with a big bang but over time we realized its not a miracle drug. JAMA article of April 2005 actually showed that it may be associated with an increased 30-day mortality . Later reviews and reports against Netrecor and its association with renal dysfunction intensified the debate. It appears that up to date: Netrecor is indicated only for severe acute decompensated congestive heart failure (CHF) with dyspnea at rest or minimal activity and is NOT indicated for intermittent or scheduled repetitive use, to improve renal function or for diuresis. Using Netrecor merely with BNP level is not advisable.

References: Click here to get article
1.
Short-term Risk of Death After Treatment With Nesiritide for Decompensated Heart Failure - A Pooled Analysis of Randomized Controlled Trials - JAMA. 2005;293:1900-1905. (full article available with free registration)
2.
Nesiritide — Not Verified - NEJM, Volume 353:113-116, July 2005
3.
Scios press releases
4. Scientific papers related to Netrecor


Re. Selective Digestive-tract Decont. - posted yesterday

Response 1: If you look at the bulk of the literature on this topic from Europe, they exclude ICU's with MRSA concerns. This amounts to most US facilities.

Response 2: SDD may not be feasible in ICUs with high prevalence of VRE and MRSA. Click
this Medscape article (register free to read).

Monday, December 05, 2005

Tuesday December 6, 2005
Selective digestive tract decontamination (SDD)


SDD is widely practiced in europe but its use in USA remains low due to fear of increase in antibitics resistance. The technique applies use of oral and enteral nonabsorbable antibiotics (polymyxin B, tobramycin and amphotericin B - new reports suggest benefit of Probiotics) and IV antibiotics (cefotaxime) in the hope to prevent and eradicate oropharyngeal and gastrointestinal carriage of potentially pathogenic microorganisms (PPMs), leaving the indigenous flora, which may protect against overgrowth of resistant bacteria. Most studies favour use of SDD in prevention of ventilator-associated pneumonia (VAP) and overall decrease in ICU mortality. Are we ready to embark on this journey?

References: Click here to get article
1.
Selective digestive decontamination decreases mortality and morbidity in the intensive care - Canadian Journal of Anesthesia 51:737-739 (2004)
2.
Selective decontamination of the digestive tract reduced intensive care unit and hospital mortality in adults - Evidence-Based Nursing 2004; 7:47
3.
Selective decontamination of the digestive tract reduces mortality in critically ill patients - Critical Care 2003, 7:107-110
4. Guidelines for the Management of Adults with Hospital-acquired, Ventilator-associated, and Healthcare-associated Pneumonia - Am. J. Respir. Crit. Care Med., February 15, 2005; 171(4): 388 - 416

Sunday, December 04, 2005

Monday December 5, 2005
C-Reactive Protein (CRP) - marker of mortality in ICU ?

Interesting work done from Belgium looking into correlation of C-Reactive Protein with mortality in ICU. Patients with high CRP levels at ICU admission had more severe organ dysfunction, longer ICU stays, and higher mortality rates (36% if ICU admission serum CRP levels > 10 mg/dL). On 48 hours followup - decrease in CRP level was associated with a mortality rate of 15.4%, while an increased CRP level was associated with a mortality rate of 60.9%.

Clinical significance: Admission CRP level can identify the patient who may require more aggressive interventions to prevent complications and similarly serial measurements.

C-Reactive Protein Levels Correlate With Mortality and Organ Failure in Critically Ill Patients - Chest. 2003;123:2043-2049
Sunday December 4, 2005
Epidemic of new fluoroquinolone induce strain of C. Diff.

Centers for Disease Control and Prevention has release a report on epidemic of new fluoroquinolone induce strain of C. Diff. The New England Journal of Medicine has put out 2 reports on epidemic of a new strain of Clostridium difficile on Dec. 8 2005 issue (see in references). It is called BI/NAP1 isloates and showing a lot more resistance to fluoroquinolones (Gatifloxacin and Moxifloxacin). It appears more toxic as canadian report shows 30-day attributable mortality rate of 6.9 percent. Regular laboratory may not be equipped to do the test so you may have to specifically ask for it. Be more vigilant as early treatment is the key and with no response to oral metronidazole, early switch to oral vancomycin may be needed.


Alochol can’t kill C.diff spores so washing with soap and water is required.

Report 1: Georgia, Illinois, Maine, New Jersey, Oregon, and Pennsylvania.

Report 2: 12 hospitals in Quebec, Canada

References:
1. An Epidemic, Toxin Gene–Variant Strain of Clostridium difficile
2. A Predominantly Clonal Multi-Institutional Outbreak of Clostridium difficile–Associated Diarrhea with High Morbidity and Mortality
3. The New Clostridium difficile — What Does It Mean?

Saturday, December 03, 2005

Saturday December 3, 2005
Low tidal volume (TV) anyway?

From
ARMA trial of ARDSNET we learned about benefits of low TV in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) but reports and studies have shown benefit of low TV (or harm of high TV) in non-ALI/ARDS too. See this retrospective cohort study of 332 patients who did not have acute lung injury but required mechanical ventilation - 80 patients developed ALI within the first 5 days of mechanical ventilation. One of the main risk factors in developing ALI was the use of large tidal volume in dose-dependent manner (odds ratio 1.3 for each ml above 6 ml/kg predicted body weight). 2 lessons learned:

1) We still tend to ignore the “ideal” body weight depending on height and gender and are using “actual” body weight for initial TV setup.

2) We still don’t know the “optimum” TV on non-ALI patients.


References: click to get abstract/article


1.
Ventilator-associated lung injury in patients without acute lung injury at the onset of mechanical ventilation Critical Care Medicine. 32(9):1817-1824, September 2004

Thursday, December 01, 2005

bis

Friday December 2, 2005
BIS (Bispectral Index) monitoring


BIS monitoring is an underutilize tool in ICUs particularly in patients on paralytics. Experts are still debating its full value. General guide regarding BIS monitoring level, if use:

100 - 80: Awake or sedation is light
60 - 80: Respond to command but may not recall the event.
40 - 60: Probably sedation is optimum.
Less than 40: Deep sedation
0: No EEG like in barbiturate coma or deep hypothermia.


Key is to monitor BIS sedation scale with hemodynamics together as BIS doesn’t provide any measurement of analgesia which may be needed simultaneously with sedation.

References: click to get abstract/article
1.
BIS Monitoring to Prevent Awareness during General Anesthesia - Anesthesiology: Volume 94(3) March 2001 pp 520-522
2.
BIS monitoring in ICU: advantages of the new XP generation - Critical Care 2002, 6(Suppl 1):P68
3. Potential Benefits of Bispectral Index Monitoring in Critical Care: A Case Study - Crit Care Nurse 2003 Aug;23(4):45-52
4. Use of BIS Monitoring Was Not Associated with a Reduced Incidence of Awareness - Anesth Analg.2005; 100: 1221

Thursday December 1, 2005
Pulmonary Artery Occlusion Pressure and PEEP


There are 3 ways to correct/manage pulmonary artery occlusion pressure or pulmonary capillary wedge pressure (PCWP) in patients with PEEP (positive end-expiratory pressure) over 10.

1. Follow the trend of PCWP co-relating with other clinical data and interventions.

2. Corrected PCWP = Measured PCWP - .5 x (PEEP/1.36)
e.g. If measured PCWP is 20 and applied PEEP is 16:
Corrected PCWP = 20 - .5 (16/1.36) = 14.12

3. Corrected PCWP = measured PCWP - esophageal pressure.


Temporary discontinuation of PEEP to measure PCWP is not safe and should be avoided.

References: click to get abstract/article
1.
Influence of positive end-expiratory pressure on left ventricular performance - NEJM, Feb. 1981, Volume 304:387-392
2. Monitoring Pulmonary Artery Pressure - Crit Care Nurse 2004 Jun;24(3):67-70
3.
Measuring Intra-Esophageal Pressure to Assess Transmural Pulmonary Arterial Occlusion Pressure in Patients with Acute Lung Injury: A Case Series and Review - Respir Care 2000;45(9):1072-1084
4.
Swan-Ganz Catheterization - online emedicine.com