A Case of Suspected Negative Pressure Pulmonary Edema after General Anesthesia.

Negative pressure pulmonary edema (NPPE) can occur rapidly after the release of an upper airway obstruction. In general anesthesia, NPPE can be caused by laryngospasm after extubation. This report describes a case in which NPPE was thought to have occurred after extubation during general anesthesia in a disabled person. The patient was a 28-yearold man, 160 cm in height and 56 kg in weight, who was scheduled for dental caries treatment under ambulatory general anesthesia due to intellectual disability. After induction of general anesthesia, nasal intubation was performed after sufficient oral suctioning to remove a large amount of serous secretion. After completion of dental treatment, pressurized extubation was performed after oral suctioning as sufficient spontaneous breathing and body movement were observed. Immediately after extubation, SpO2 dropped to 80%, subsequently recovering to 99% under oxygen administration at 5 liter/min with an oxygen mask. It dropped to approximately 85% again, however, when administration of oxygen was discontinued. Although communication with the patient was difficult, no expression of anguish or dyspnea was observed. A chest radiograph showed symmetric middle-lobe and lingular segment infiltrates, and the patient was transferred to the nearest general hospital. No obvious clinical findings other than a decrease in SpO2 were observed, suggesting NPPE as a result of airway narrowing due to secretions.

Effects of Remifentanil on Cardiovascular Stimulation Caused by Local Anesthetic With Epinephrine: A Power Spectral Analysis.

The objectives of this research were to investigate (a) what was the most effective infusion rate of remifentanil and (b) the degree to which sympathomimetic effects were involved with cardiovascular stimulation by using a power spectral analysis of heart rate variability (HRV). A total of 63 healthy individuals scheduled for sagittal split ramus osteotomy were enrolled and randomly allocated to 1 of 3 groups: remifentanil infusion rate of 0.1, 0.2, or 0.4 µg/kg/min. Anesthesia was maintained with remifentanil and propofol. Before the surgical procedure, 2% lidocaine containing 12.5 µg/mL epinephrine was administered in the surgical field for local anesthesia. Systolic blood pressure (SBP), heart rate (HR), low-frequency (LF) and high-frequency (HF) components in HRV power spectral analysis, and the LF/HF ratio were analyzed. Increases in SBP and HR were observed after local anesthesia in all 3 groups, but no significant differences were observed between the groups. Remifentanil infusion at 0.1 µg/kg/min may be appropriate to minimize cardiovascular stimulation caused by exogenous epinephrine from local anesthesia. Although a rise in the LF/HF ratio was observed after local anesthesia in all groups, no relationship was observed between the cardiovascular changes and the increase in LF/HF ratio. This suggests that sympathomimetic effects are involved to a lesser extent with the cardiovascular stimulation caused by exogenous epinephrine.