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The Cochrane Database of Systematic... Nov 2016Inadvertent perioperative hypothermia (a drop in core temperature to below 36°C) occurs because normal temperature regulation is disrupted during surgery, mainly... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Inadvertent perioperative hypothermia (a drop in core temperature to below 36°C) occurs because normal temperature regulation is disrupted during surgery, mainly because of the effects of anaesthetic drugs and exposure of the skin for prolonged periods. Many different ways of maintaining body temperature have been proposed, one of which involves administration of intravenous nutrients during the perioperative period that may reduce heat loss by increasing metabolism, thereby increasing heat production.
OBJECTIVES
To assess the effectiveness of preoperative or intraoperative intravenous nutrients in preventing perioperative hypothermia and its complications during surgery in adults.
SEARCH METHODS
We searched the Cochrane Central Register of Controlled Trials (CENTRAL; November 2015) in the Cochrane Library; MEDLINE, Ovid SP (1956 to November 2015); Embase, Ovid SP (1982 to November 2015); the Institute for Scientific Information (ISI) Web of Science (1950 to November 2015); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL, EBSCO host; 1980 to November 2015), as well as the reference lists of identified articles. We also searched the Current Controlled Trials website and ClincalTrials.gov.
SELECTION CRITERIA
Randomized controlled trials (RCTs) of intravenous nutrients compared with control or other interventions given to maintain normothermia in adults undergoing surgery.
DATA COLLECTION AND ANALYSIS
Two review authors extracted data and assessed risk of bias for each included trial, and a third review author checked details if necessary. We contacted some study authors to request additional information.
MAIN RESULTS
We included 14 trials (n = 565), 13 (n = 525) of which compared intravenous administration of amino acids to a control (usually saline solution or Ringer's lactate). The remaining trial (n = 40) compared intravenous administration of fructose versus a control. We noted much variation in these trials, which used different types of surgery, variable durations of surgery, and different types of participants. Most trials were at high or unclear risk of bias owing to inappropriate or unclear randomization methods, and to unclear participant and assessor blinding. This may have influenced results, but it is unclear how results might have been influenced.No trials reported any of our prespecified primary outcomes, which were risk of hypothermia and major cardiovascular events. Therefore, we decided to analyse data related to core body temperature instead as a primary outcome. It was not possible to conduct meta-analysis of data related to amino acid infusion for the 60-minute and 120-minute time points, as we observed significant statistical heterogeneity in the results. Some trials showed that higher temperatures were associated with amino acids, but not all trials reported statistically significant results, and some trials reported the opposite result, where the amino acid group had a lower core temperature than the control group. It was possible to conduct meta-analysis for six studies (n = 249) that provided data relating to the end of surgery. Amino acids led to a statistically significant increase in core temperature in comparison to those receiving control (MD = 0.46°C 95% CI 0.33 to 0.59; I 0.0%; random-effects; moderate quality evidence).Three trials (n = 155) reported shivering as an outcome. Meta-analysis did not show a clear effect, and so it is uncertain whether amino acids reduce the risk of shivering (RR 0.36, 95% CI 0.13 to 1.00; I = 93%; random-effects model; very low-quality evidence).
AUTHORS' CONCLUSIONS
Intravenous amino acids may keep participants up to a half-degree C warmer than the control. This difference was statistically significant at the end of surgery, but not at other time points. However, the clinical importance of this finding remains unclear. It is also unclear whether amino acids have any effect on the risk of shivering and if intravenous nutrients confer any other benefits or harms, as high-quality data about these outcomes are lacking.
Topics: Administration, Intravenous; Adult; Amino Acids; Body Temperature; Fructose; Humans; Hypothermia; Isotonic Solutions; Randomized Controlled Trials as Topic; Ringer's Lactate; Shivering; Sodium Chloride; Time Factors
PubMed: 27875631
DOI: 10.1002/14651858.CD009906.pub2 -
Annales de Biologie Clinique 2004To identify, through a systematic review of the literature, the laboratory variables that, in addition to performance status and to extent of the disease, would allow a... (Review)
Review
OBJECTIVE
To identify, through a systematic review of the literature, the laboratory variables that, in addition to performance status and to extent of the disease, would allow a more accurate stratification of small-cell lung cancer patients who participate in chemotherapy trials, with or without radiotherapy. Secondary aim: to compare the results of our systematic review with the recommendations made in current clinical practice guidelines.
METHODS
Update of two recently published systematic reviews, without meta-analysis, following the recommendations of the International Federation of Clinical Chemistry and Laboratory Medicine, and taking into account the Consolidated Standards of Reporting Trials statement.
RESULTS
Of 1143 publications retrieved, exclusion and inclusion criteria allow us to include 13 studies in our review. The three variables which were the most often found significant in multivariate statistical analysis, were: pre-therapeutic levels of laboratory variables (13/13), performance status (12/13), and degree of tumour invasion (10/10). Among the laboratory variables, serum lactate dehydrogenase (LDH) is the only one that was quite consistently found to be of independent prognostic significance, with p values or hazard ratios quite close to those obtained with performance status, or with extent of the disease. The recommendations made in the four clinical practice guidelines that we retrieved, are often vague regarding laboratory variables, and sometimes they even contradict each others.
CONCLUSIONS
Available evidence would support the recommendation that pretreatment LDH should be systematically measured in order to stratify patients in therapeutic trials. If other laboratory variables were to be measured in addition to LDH for this purpose, it seems that alkaline phosphatase (ALP), and to a lesser extent, sodium and white blood cell counts, might be the best suited ones. Nevertheless, further studies are necessary to more clearly support this latter recommendation. Available evidence would not support the measurement of any other laboratory variable in this context, before, during, or after treatment. Our recommendations are more in agreement with the recommendations made in the clinical practice guidelines that use evidence-based methods than with the guidelines that do not.
Topics: Carcinoma, Small Cell; Clinical Laboratory Techniques; Clinical Trials as Topic; Humans; Lung Neoplasms; Practice Guidelines as Topic
PubMed: 15047471
DOI: No ID Found