Subglottic Stenosis After Surgery for Congenital Heart Disease: A Spectrum of Severity

Subglottic Stenosis Following Cardiac Surgery With Cardiopulmonary Bypass in Infants and Children

OBJECTIVES

To determine the 1) incidence of subglottic stenosis in infants and children following cardiac surgery with cardiopulmonary bypass and 2) risk factors associated with its development.

DESIGN

Retrospective cohort study.

SETTING

Tertiary children's hospital in California.

PATIENTS

Infants and children who underwent cardiac surgery with cardiopulmonary bypass.

INTERVENTIONS

Diagnosis of subglottic stenosis by tracheoscopy.

MEASUREMENTS AND MAIN RESULTS

The incidence of subglottic stenosis at our institution during the study period was 0.7%. Young age (p = 0.014), prolonged cardiopulmonary bypass (p = 0.03), and prolonged mechanical ventilation (p < 0.01) were associated with the development of subglottic stenosis. Gender, chromosomal anomaly, presence of a cuffed endotracheal tube, and lowest core temperature during cardiopulmonary bypass were not associated with the development of subglottic stenosis.

CONCLUSIONS

The incidence of subglottic stenosis was less than that previously reported in this population. Although the incidence is relatively low, subglottic stenosis is a serious complication of tracheal intubation and all measures to prevent subglottic stenosis should be undertaken.

Incremental change in cross sectional area in small endotracheal tubes: A call for more size options

OBJECTIVE

To elucidate the relatively large incremental percent change (IPC) in cross sectional area (CSA) in currently available small endotracheal tubes (ETTs), and to make recommendation for lesser incremental change in CSA in these smaller ETTs, in order to minimize iatrogenic airway injury.

METHODS

The CSAs of a commercially available line of ETTs were calculated, and the IPC of the CSA between consecutive size ETTs was calculated and graphed. The average IPC in CSA with large ETTs was applied to calculate identical IPC in the CSA for a theoretical, smaller ETT series, and the dimensions of a new theoretical series of proposed small ETTs were defined.

RESULTS

The IPC of CSA in the larger (5.0-8.0 mm inner diameter (ID)) ETTs was 17.07%, and the IPC of CSA in the smaller ETTs (2.0-4.0 mm ID) is remarkably larger (38.08%). Applying the relatively smaller IPC of CSA from larger ETTs to a theoretical sequence of small ETTs, starting with the 2.5 mm ID ETT, suggests that intermediate sizes of small ETTs (ID 2.745 mm, 3.254 mm, and 3.859 mm) should exist.

CONCLUSION

We recommend manufacturers produce additional small ETT size options at the intuitive intermediate sizes of 2.75 mm, 3.25 mm, and 3.75 mm ID in order to improve airway management for infants and small children.

Airway Management following Pediatric Cardiothoracic Surgery

Objectives

(1) Review airway management in pediatric patients undergoing cardiothoracic surgery (CTS); (2) determine the incidence of airway-related complications of CTS in this population.

Design

Case series with chart review.

Setting

Tertiary care children’s hospital.

Patients

Children undergoing CTS over a 4-year period.

Methods

Patients who underwent CTS at a single, tertiary care, children’s hospital between June 1, 2007, and May 31, 2011, were retrospectively reviewed; those <18 years who had open CTS were included. Statistical analysis examined relationships of intubation duration, complications, and need for tracheotomy while comparing patient characteristics, comorbidities, and types of surgery.

Results

Eight hundred seventy-five primary surgeries in 745 patients met inclusion criteria. Mean postoperative intubation duration was 7.2 days and median 3 days. On univariate analysis, significantly longer postoperative intubation requirements were found in patients younger in age, with congenital comorbidities or prematurity, with preoperative ventilation requirements, and those with early postoperative complications. Multivariate analysis found younger age, presence of congenital comorbidities, preoperative intubation requirements, and early postoperative complications each lengthen ventilation requirements. Four patients developed vocal cord paralysis and 5 developed phrenic nerve palsy. Nineteen patients required tracheotomy.

Conclusions

In this large cohort, CTS in the pediatric population is associated with few long-term or permanent airway-related complications. Patients who are younger in age and those with congenital comorbidities, preoperative ventilation requirements, or early postoperative complications required longer periods of postoperative intubation.