Risk of Hypoxemia by Induction Technique Among Infants and Neonates Undergoing Pyloromyotomy

Abstract

BACKGROUND: In patients presenting for pyloromyotomy, most practitioners prioritize rapid securement of the airway due to concern for aspiration. However, there is a lack of consensus and limited evidence on the choice between rapid sequence induction (RSI) and modified RSI (mRSI). METHODS: The medical records of all patients presenting for pyloromyotomy from May 2012 to December 2018 were reviewed. The risk of hypoxemia (peripheral oxygen saturation [Spo 2], <90%) during induction was compared between RSI and mRSI cohorts for all patients identified as well as in the neonate subgroup by univariate and multivariable logistic regression analysis. Complications (aspiration, intensive care unit admission, bradycardia, postoperative stridor, and hypotension) and initial intubation success for both cohorts were also compared. RESULTS: A total of 296 patients were identified: 181 in the RSI and 115 in the mRSI cohorts. RSI was associated with significantly higher rates of hypoxemia than mRSI (RSI, 30% [23%–37%]; mRSI, 17% [10%–24%]; P = .016). In multivariable logistic regression analysis of all patients, the adjusted odds ratio (OR) of hypoxemia for RSI versus mRSI was 2.8 (95% confidence interval [CI], 1.5–5.3; P = .003) and the OR of hypoxemia for multiple versus a single intubation attempt was 11.4 (95% CI, 5.8–22.5; P < .001). In multivariable logistic regression analysis of neonatal subgroup, the OR of hypoxemia for RSI versus mRSI was 6.5 (95% CI, 2.0–22.2; P < .001) and the OR of hypoxemia for multiple intubation versus single intubation attempts was 18.1 (95% CI, 4.7–40; P < .001). There were no induction-related complications in either the RSI and mRSI cohorts, and the initial intubation success rate was identical for both cohorts (78%). CONCLUSIONS: In infants presenting for pyloromyotomy, anesthetic induction with mRSI compared with RSI was associated with significantly less hypoxemia without an observed increase in aspiration events. In addition, the need for multiple intubation attempts was a strong predictor of hypoxemia. The increased risk of hypoxemia associated with RSI and multiple intubation attempts was even more pronounced in neonatal patients.

Emerging trends, techniques, and equipment for airway management in pediatric patients

“…Adjusted odds ratio (AOR) of hypoxemia for all patients having RSI vs mRSI was 2.8, and in subgroup analysis of neonatal patients, AOR was 6.5, indicating that younger, more vulnerable patients may derive even greater protective benefit from mRSI. Though pulmonary aspiration is a rare event, in the limited sample size of this study, there was again no indication that mRSI resulted in an observed increase in pulmonary aspiration . We have made routine use of modified RSI with low‐pressure positive pressure ventilation prior to intubation of infants with full stomach considerations part of our clinical practice.…”

“…The familiar structure of the blade and lack of angulation is expected to decrease technical complications compared with a hyperangulated blade . The ability to convert from a direct to indirect technique within the same airway attempt may minimize attempts, and thus, complications, as the need for multiple intubation attempts, have been associated with increased rates of hypoxemia even in otherwise healthy neonates and infants …”

Logistic Regression in Medical Research

“…In this issue of Anesthesia & Analgesia , Park et al 1 report results of an observational study on the risk of hypoxemia (defined as a peripheral oxygen saturation <90%) during rapid sequence induction (RSI) versus a modified RSI technique in infants and neonates undergoing pyloromyotomy. The authors used logistic regression to analyze the association between the induction technique and the risk of hypoxemia while controlling for potential confounders.…”

“…Researchers can then study the relationship between each variable and the binary (dichotomous) outcome while holding constant the values of the other independent variables. This is particularly useful not only to understand the independent relationship of each variable with the outcome, but also, as done by Park et al, 1 to adjust the estimates for the effects of confounding variables 4 in observational research.…”

“…The odds ratio indicates how much the odds of a particular outcome change for a 1-unit increase in the independent variable (for continuous independent variables) or versus a reference category (for categorical variables). For example, the adjusted odds ratio of 2.8 (95% confidence interval [CI], 1.5-5.3) reported by Park et al 1 indicates that the odds of hypoxemia is estimated to be almost 3 times higher when receiving conventional RSI as compared to the modified technique (the reference category in their analysis), after controlling for and thus accounting for the potential confounders.…”