Medpedia & Twitter

Critical Insight has been included as a founding member of Medpedia’s News & Analysis website. Medpedia is an exciting project to build a first class medical resource on the internet using world wide wiki collaboration in association with major US universities, you can find more details here. Critical Insight was started to try and encourage similar professional collaboration and discussion, and I hope that international visitors will find Critical Insight useful.

If you struggle to visit Critical Insight frequently why not be notified of new posts ? It’s been possible to receive email notifications and RSS feeds for some time, and you now have a third option – following Critical Insight on Twitter! Click the buttons on the right and follow the instructions.

Special K – time for a reappraisal ?

2 recent articles highlight the potential benefit of an often overlooked induction agent in critically ill patients.

Etomidate versus ketamine for rapid sequence intubation in acutely ill patients: a multicentre randomised controlled trial. Jabre, P. et al. Lancet. Volume 374, Issue 9686, Pages 293 – 300, 25 July 2009.

This multicentre, randomised, blinded trial in 65 french ICUs & 12 field teams enrolled 655 patients to either etomidate or ketamine for emergent intubation for critical illness. Patients were analysed only if they remained in ICU after day 3 (469). Adequate and reasonable power calculation, including predetermined septic & trauma subgroups. Primary end point was maximal SOFA score within 3 days (chosen as etomidate’s effects on adrenocortical axis thought to last <48 hrs). Secondary end points included intubation conditions, and 28 day ICU stay, catecholamine requirement, mortality & adrenocortical insufficiency.

Derby’s Finest

Two excellent recent articles from local clinicians that had to be featured on Critical Insight. An upcoming post will include a review article on Ketamine in ICU, but first…

Should we really be more “balanced” in our fluid prescribing ? Morris, C. Boyd, A. Reynolds, N. Anaesthesia, 2009 Jul;64(7):703.

A very good editorial questioning the rush away from hypercholreamic solutions despite the lack of clear evidence of benefit. They’re making a habit of insightful editorials. Without stealing their thunder, they make some excellent points regarding the potential physiological impact of negative anions (such as lactate and acetate) in situations of poor organ perfusion. A question the editorial doesn’t ask which springs to mind – how are we to assess the risk of fluid regimens without having to repeat the SAFE study for every potential option? At the same time can we tolerate the introduction of new fluids into the critically ill with very little evidence base ?

Steroids for Post Intubation Stridor

A recent Cochrane review of the use of steroids to prevent post extubation stridor in adults and children has been comprehensively reviewed by the McMaster EBM unit for BMJ Evidence. The text below is from their site, which is free access.

BACKGROUND: Post-extubation stridor may prolong length of stay in the intensive care unit, particularly if airway obstruction is severe and re-intubation proves necessary. Some clinicians use corticosteroids to prevent or treat post-extubation stridor, but corticosteroids may be associated with adverse effects ranging from hypertension to hyperglycaemia, so a systematic assessment of the efficacy of this therapy is indicated.

PIRO for Ventilator associated pneumonia

PIRO score for community-acquired pneumonia: A new prediction rule for assessment of severity in intensive care unit patients with community-acquired pneumonia. Lisboa et al. Critical Care Medicine. 37(2):456-462, Feb 2009.

Thanks to Dr. Saule for the presentation on this paper, which can be found in the blue box named PIRO VAP.

Dopexamine & Meta-analysis

Meta-analyses of the effects of dopexamine in major surgery: do all roads lead to Rome? J. J. Pandit. Anaesthesia. 64;6:585-8. (Editorial)

Meta-analyses of the effect of dopexamine on hospital mortality. Gopal et al. Anaesthesia. 64;6:589-94.

Effect of dopexamine infusion on mortality following major surgery: individual patient data multi-regression analysis of published clinical trials. Crit Care Med. 2008 Apr;36(4):1323-9

Two recent meta-analysis have been published in answer to the question “does dopexamine reduce mortality in high risk general surgical patients”, with conflicting results. Pearse’s group found no difference in mortality using the entire data set, but a 50% mortality reduction with low-dose infusions. Gopal’s group found no difference using essentially the same data set, but a different statistical methodology. Panjit’s accompanying editorial does an excellent job of dissecting out why such apparent large differences might arise from the same data, and is recommended.

The take home message for me is that the results of combining heterogeneous studies together into meta-analysis tell us more about the statistical method than they do about the clinical question. Does dopexamine have a role? Is it the dopamine renal failure story all over again? I’m afraid we’ll need more data…..

Bleedin’ starch

Rapidly Degradable Hydroxyethyl Starch Solutions Impair Blood Coagulation After Cardiac Surgery:A Prospective Randomized Trial. Schramko, A. A et al. Anesth Analg 2009;108:30-6

Thanks to Lynsey Davies & the QMC journal club for reviewing this recent paper. Although the numbers are small, and their end points may not be clinically significant, the potential implications for routine use of starches are important. Especially since the publication of the VISEP trial. You can find Dr. Davies’s presentation in the blue box, named starch and coagulation.

Physiology at the extremes

Bubble Trouble : A review of diving physiology. Levitt, D & Millar, I. Post Graduate Med J. 2008; 84 :571-78.

Arterial Blood Gas and oxygen content in climbers on Mount Everest. Grocott, M et al. NEJM. 2009. 360:2;140-49

Something a bit different from the usual critical appraisal. Two recent papers highlighting the potential of studying normal physiology under extreme conditions for increasing our understanding of the physiology of critical illness, and a good read as well! The Caudwell Everest expedition documented paO2 s of 2.7 kPa on the summit, quite incredible. The first paper is a well written summary of diving physiology & pathology which is of interest, especially if you occasionally connect yourself to a ventilation circuit!

Dexmedetomidine vs Midazolam

Dexmedetomidine vs Midazola for sedation of critically ill patients : A randomised control trial. Riker, R. et al. JAMA 301 (5) 489-99.

This prospective, double blind, multicentred RCT compared the alpha agonist dexmedotomdine against midazolam. It was designed to assess safety & efficacy. A total of 375 patients expected to be ventilated for > 24hrs were randomised to either agent targeted to a RASS score of between -2 to +1. Primary outcome measure was period of time within target range, secondary end points included delirium scores & duration of ventilation

Management of Subarachnoid Heamorrhage

Management of aneurysmal subarachnoid heamorrhage. Dringer. M. Critical Care Medicine 37 (2) Feb 2009; 432-440.

A useful & comprehensive educational review article from CCM on the management of SAH, highlighted for interest. Unfortunately for copyright reasons we can’t provide a link to the pdf, but you can access it from the above link if you have an ATHENS account.