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A shaded callout box on page 128 of the article "Physiological Monitoring for Critically Ill Patients: Testing a Predictive Model for the Early Detection of Sepsis"1 states: "Hypothermia may not be related to sepsis, though current practice protocols often include it." However, research2–4 has shown that hypothermia is predictive of sepsis in elderly and very young patients. That is why the Surviving Sepsis Campaign (SSC) includes hypothermia in the list of screening criteria for the detection of sepsis onset.
Also, the discussion section in the article contains 2 paragraphs that attempt to disassociate hypothermia from prediction of sepsis without convincing data to support such a claim. In fact, data that were presented had major flaws.
First of all, the author compared mean temperatures of septic versus nonseptic patients in all study subjects and stated that the average temperature was higher in patients with sepsis (36.31°C, SD 0.88, n = 123) than in those without sepsis (36.11°C, SD 0.96, n = 95). Had the mean temperature values for septic versus nonseptic patients been significantly different, which they were not (I performed the t test and the null hypothesis was not rejected for an 
of .05), the only conclusion that could have been drawn was that patients with sepsis on average had a higher temperature than did patients without.
This author’s logic neither supports nor contradicts the hypothesis that hypothermia is a predictive parameter of sepsis. Because of the biphasic nature of either hypothermia or hyperthermia occurring with the onset of sepsis in some patient populations, comparison should have been made between patients with temperatures less than 36°C and those who were normothermic (36°–38°C) to show the association between hypothermia and sepsis.
Most important, it is well established that hypothermia is predictive of sepsis in very young and very old patients, as research2–4 suggests and SSC guidelines5 state. Neither of these patient populations were independently studied by the author and nowhere in the article was the relationship between sepsis, hypothermia, and patient age mentioned.
University of California, San Francisco, California
REFERENCES
I would like to thank Ryan Sincic for his thoughtful comments on my recently published article1; I appreciate the level of detail he offers in his letter. Mr Sincic is correct that I did not qualify my discussion on hypothermia with specifics regarding age. With respect to hypothermia as a predictor of sepsis in the very young, my sample included only adults, and the demographics regarding the ages of the study subjects were specified in the table provided on page 125.
The results of this study apply only to critically ill adult patients. However, hypothermia as a predictor of sepsis is not well established either in the very young or very old based on the references provided by Mr Sincic. As part of my preparation in writing the manuscript, a search of the literature did not reveal compelling empirical evidence on hypothermia as a good predictor for sepsis in any age group. Therefore, it is my conclusion that much more convincing data are needed to make such a claim.
The demographic table referenced above also provides data on the comparison of the values of the lowest temperature between septic and nonseptic patient groups, which do indicate a significant difference between groups. Mr Sincic states that he performed a t test that did not show a difference between the groups, but such a comparison is not valid because he did not request access to data. Also, because the data did not meet the required assumptions for parametric comparison, a t test is not an appropriate analysis to conduct, which is why the nonparametric Mann-Whitney U test was used.
Mr Sincic makes a good point about the potential value of regrouping the patients and comparing those with a temperature less than 36°C with those in the normothermic range. I actually peformed such a comparison in my original analyses, but found there were more patients in the nonseptic group who were hypothermic than in the septic group, thereby yielding the same results as those I reported.
Finally, the recommendations included in the SSC all were based on the best available evidence at the time of their 2004 publication. The recommendations included in the SSC were based on data that spanned the range from expert opinion to prospective multicenter trials. This was the reason that each recommendation was graded based on the supporting evidence: to provide complete transparency. The grading system used was limited to the treatment recommendations and does not denote specific ratings for the screening criteria.
Many experienced critical care clinicians I know believe that hypothermia is actually a late—rather than an early—sign of sepsis, and therefore that it has little predictive value. However, because the screening criteria are included as a portion of the total package of the "early goal-directed therapy" recommendations, one might potentially consider them as a grade B (based on a single investigation).
Ultimately, the point of my research was to add to the body of knowledge regarding the SSC sepsis screening recommendations—a point that is clearly stated in the study objectives.
Philips Medical Systems, Andover, Mass
REFERENCE
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