Plethysmographic pulse wave amplitude is an effective indicator for intravascular injection of epinephrine-containing epidural test dose in sevoflurane-anesthetized pediatric patients

Abstract

BACKGROUND: Plethysmographic pulse wave amplitude (PPWA) was effective in detecting intravascular injection of epidural test dose with 100% sensitivity and specificity in adults. We evaluated the efficacy of PPWA in detecting intravascular injection of a simulated epidural test dose during sevoflurane anesthesia in pediatric patients. METHODS: Eighty infants and children were randomized to receive either 0.5 minimal alveolar concentration (MAC) or 1 MAC sevoflurane and nitrous oxide in oxygen. Patients in each anesthesia group were further randomized to receive either 0.1 mL/kg of 1% lidocaine with 1:200,000 epinephrine (0.5 μg/kg of epinephrine) IV to simulate the intravascular injection of epidural test dose or saline. Heart rate (HR), systolic blood pressure (SBP), and PPWA were monitored for 5 min after injection. A positive test response was defined as HR increase ≥ 10 bpm, SBP increase ≥ 15 mm Hg, and PPWA decrease ≥ 10%. RESULTS: Injecting the test dose resulted in an average maximum PPWA decrease by 69% ± 18% and 58% ± 14% at 79 ± 22 and 80 ± 19 s in the 0.5 MAC and 1 MAC sevoflurane groups, respectively. The sensitivity, specificity, positive predictive, and negative predictive values for PPWA were 100% in both sevoflurane groups, whereas by using HR and SBP criteria, the sensitivity was 90% and 95% respectively during 0.5 MAC sevoflurane anesthesia and 85% for both during 1 MAC sevoflurane anesthesia. CONCLUSION:: PPWA is effective for detection of an intravascular injection of a simulated epidural epinephrine-containing test dose in pediatric patients. © 2008 International Anesthesia Research Society.