Abstract 17199: Airway Mucociliary Clearance is Impaired After Infant Congenital Cardiac Surgery

Introduction: A link between congenital heart disease and airway ciliary dyskinesia has been identified. Postoperative pulmonary dysfunction is highly prevalent after cardiac surgery and contributes to morbidity, mortality, and healthcare costs. We hypothesized that respiratory mucociliary clearance (MCC) would be impaired in the immediate postoperative period after infant congenital cardiac surgery. Methods: 41 infants from 5-254 days old underwent MCC scans using nebulized technetium-99m sulfur colloid either immediate postoperative or later postoperative periods after congenital cardiac surgery. Physiologic variables and medications at the time of scan were recorded. Results: There was no significant correlation between MCC and age, gender, race or any of the of the physiologic variables, such as temperature, SpO2, or FiO2, at the time of the MCC scan. MCC was lowest on the first 2 postoperative days, increased at days 3-7, and highest beyond postoperative day 7 (Fig1). Fentanyl (p=0.023) and paralytics agents (p=0.018) were significantly associated with lower MCC, while benzodiazepines (p=0.447) and dexmedetomidine (p=0.675) showed no measurable impact (Table 1). Conclusion: We show for the first time, with quantitative measurements, the near absence of infant MCC in the immediate postoperative period after congenital cardiac surgery. This may be exacerbated by opioid exposure, which should be minimized. Our results further suggest sedative alternatives such as benzodiazepines and dexmedetomidine are preferable to help optimize infant airway clearance. This may reduce ICU length of stay and improve outcomes after cardiac surgery.

Postoperative Pulmonary Dysfunction and Mechanical Ventilation in Cardiac Surgery

Postoperative pulmonary dysfunction (PPD) is a frequent and significant complication after cardiac surgery. It contributes to morbidity and mortality and increases hospitalization stay and its associated costs. Its pathogenesis is not clear but it seems to be related to the development of a systemic inflammatory response with a subsequent pulmonary inflammation. Many factors have been described to contribute to this inflammatory response, including surgical procedure with sternotomy incision, effects of general anesthesia, topical cooling, and extracorporeal circulation (ECC) and mechanical ventilation (VM). Protective ventilation strategies can reduce the incidence of atelectasis (which still remains one of the principal causes of PDD) and pulmonary infections in surgical patients. In this way, the open lung approach (OLA), a protective ventilation strategy, has demonstrated attenuating the inflammatory response and improving gas exchange parameters and postoperative pulmonary functions with a better residual functional capacity (FRC) when compared with a conventional ventilatory strategy. Additionally, maintaining low frequency ventilation during ECC was shown to decrease the incidence of PDD after cardiac surgery, preserving lung function.

Pulmonary Protection During Cardiac Surgery: Systematic Literature Review

Ischemia-reperfusion injury occurs during heart surgery in which cardiopulmonary bypass is used. Current knowledge of the factors contributing to postoperative pulmonary dysfunction and the measures to avoid it are reviewed.