Pulmonary Mechanics During Minimally Invasive Repair of Pectus Excavatum

Phase 4 Study of Desflurane and Sevoflurane That Affect Pulmonary Mechanics During Minimally Invasive Repair of Pectus Excavatum

The aim of the current study was to compare the effects of sevoflurane and desflurane on respiratory mechanics in patients undergoing repair of pectus excavatum.

The minimally invasive technique for pectus excavatum repair was introduced by Nuss and colleagues using a metal bar to lift the depressed chest wall. This surgical procedure is usually done under general anesthesia with tracheal intubation. After inserting metal bar into the chest wall, decreased lung compliance was shown. Previous studies demonstrated that administering desflurane during anesthesia resulted in marked increases in respiratory mechanical parameters, especially in the children with airway susceptibility. Our primary hypothesis was that desflurane would cause an increase in respiratory resistance and a decrease in lung compliance compared to sevoflurane during repair of pectus excavatum.

Using random numbers, patients were divided into two groups to receive either sevoflurane or desflurane. After induction of anesthesia and intubation, the patient's lungs were ventilated in constant-flow VCV mode by an anesthetic Ventilator (Datex-Ohmeda, GE healthcare, Finland). Ventilator settings were tidal volume 10 ml/kg, inspiratory:expiratory (I:E) ratio 1:1.5, inspired oxygen concentration (FiO2) 0.5 with air, and 3 L/min of inspiratory fresh gas flow. End-inspiratory pause was set 20% of total breathing cycle. Positive end-expiratory pressure (PEEP) was not used. Respiratory rate was adjusted to maintain an end-tidal CO2 pressure of 33-35 mmHg. Patients received desflurane 6-7% for maintenance of anesthesia.

Using random numbers, patients were divided into two groups to receive either sevoflurane or desflurane. After induction of anesthesia and intubation, the patient's lungs were ventilated in constant-flow VCV mode by an anesthetic Ventilator (Datex-Ohmeda, GE healthcare, Finland). Ventilator settings were tidal volume 10 ml/kg, inspiratory:expiratory (I:E) ratio 1:1.5, inspired oxygen concentration (FiO2) 0.5 with air, and 3 L/min of inspiratory fresh gas flow. End-inspiratory pause was set 20% of total breathing cycle. Positive end-expiratory pressure (PEEP) was not used. Respiratory rate was adjusted to maintain an end-tidal CO2 pressure of 33-35 mmHg. Patients received sevoflurane 2-2.5% for maintenance of anesthesia.

Inclusion Criteria: clinical diagnosis of Pectus Excavatum undergoing minimally invasive repair Exclusion Criteria: younger than 15 year old history of upper respiratory tract infection within recent 2 weeks asthma chronic obstructive pulmonary disease previous treatment with bronchoactive drugs (B-agonist or antagonist, theophyline, anticholinergics and corticosteroid) history of neurological deficits