[Undesirable effects following the local injection of ornipressin during general anesthesia: can the risk be lessened? A prospective study].

Complications associated with local infiltration of ornithine-8-vasopressin (O-8-V) during general anesthesia (GA) are documented. Severe and extremely severe complications range around 20%; fatalities have been reported. The incidence of complications is associated with age, pre-existing cardiovascular or pulmorespiratory disease, and dosage administered. In a prospective study, we investigated 169 patients following a standardized protocol. Maximum dosage was 2 IU, diluted to 0.25 IU/ml in 0.9% saline. Patients with cardiovascular or respiratory disease and those below 1 or above 50 years of age were excluded. GA consisted of tracheal intubation and controlled ventilation with enflurane in N2O/O2 and intravenous fentanyl. Cardiovascular monitoring was by ECG with arrhythmia detection, plethysmography, and oscillometric - in some patients intraarterial - blood pressure measurement. Ventilatory monitoring included respiratory rate, tidal volume, inspiratory and expiratory O2 concentrations, capnometry, and end-tidal enflurane concentration. Local infiltration of the oral soft tissues with O-8-V was performed after a steady-state of anesthesia was achieved and 20 min before commencement of surgery. No severe or extremely severe complications or arrhythmias were observed. A moderate increase in blood pressure was seen in 43% of patients; in 10% this increase was 30-70 mmHg (systolic and/or diastolic). For data analysis, patients were allocated to 4 groups according to the dosage of O-8-V administered. Systolic and diastolic pressures increased to above control in all groups; however, no inter-group differences were found for blood pressure or heart rate. It is concluded that the risks associated with local infiltration of soft tissues with O-8-V during GA can be attenuated by a protocol such as the one established for this prospective study.(ABSTRACT TRUNCATED AT 250 WORDS)