Factors Affecting the Intubation Conditions Created by Mivacurium. A Meta-analysis and Meta-regression analysis.

Abstract

Intubation is the process of inserting a flexible tube anywhere in the human body. It is used in emergency medecine to help when a patient have difficulty in breathing, and to keep the airway open for delivery of anesthetic drugs and oxygen during surgery. Mivacurium is a non-depolarizing neuromuscular blocker used to facilitate intubation. The objective of the paper is to identify the factors that affect the probability of excellent intubation condition of Mivacurium (EIC). A total of 1029 patients from 51 randomized and controlled clinical trials were studied using meta-analysis methods. Classical and Bayesian approaches were used. In meta-analysis fixed effect and random effects models can be used to combine results from the diffent studies included in the meta-analysis. Fixed-effect model aasumes a common true effect underlying all the studies and all difference in the effect size is due to sampling error. In contrast, the random effects model allows the true effect size to vary from study to study and accounts for within study and between study variability in the estimation process. Results from fixed effect and random effect meta-analysis showed lack of significant effect of mivacurium on the probability of excellent intubation condition. Graphical and statistical methods for heterogeneity showed substantial heterogeneity in the effect size across the different studies included in the meta-analysis. Methods for publication showed no publication bias. To explore the sources of heterogeneity fixed effect and random effects meta-regression models were fitted. Results from the classical meta-regression models showed that dose, average age, time to intubation (tstart) and age by tstart interaction term are the variables that significantly affect the probability of excellent intubation condition. The Bayesian approach on the other hand showed the probability of excellent intubation condition varies with dose and age by tstart interaction for the fixed effect model, and dose for the random effect meta-regression. However, interpretation of the results should be done with caution since meta-analysis as an observational study is subject to confounding and ecological bias.