Open AccessT-Wave Amplitude as an Indicator for Detecting Intravascular Injection of Epinephrine Test Dose in Awake and Anesthetized Elderly Patients
Author(s) -
Makoto Tanaka,
Toshiaki Nishikawa
Publication year - 2001
Publication title -
anesthesia and analgesia/anesthesia and analgesia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.404
H-Index - 201
eISSN - 1526-7598
pISSN - 0003-2999
DOI - 10.1097/00000539-200111000-00061
Subject(s) - medicine , supine position , anesthesia , epinephrine , sevoflurane , lidocaine , blood pressure , saline , heart rate , cardiology
Aging is associated with reduced heart rate (HR) responsiveness to a simulated IV test dose containing epinephrine. We tested the hypothesis that a more contemporary T-wave criterion (positive if there was a > or = 25% decrease in T-wave amplitude) was applicable in both awake and anesthetized older patients. Sixteen healthy patients > or = 65 yr old first received 3 mL of normal saline IV, followed 4 min later by 1.5% lidocaine 3 mL containing 15 microg epinephrine (1:200,000) IV in the supine position when awake, and they were anesthetized with stable 2% end-tidal sevoflurane and 67% nitrous oxide. HR, systolic blood pressure (SBP) determined invasively, and lead II of the electrocardiogram were continuously recorded for 4 min after the IV injections of saline and the test dose. A sensitivity of 88% and a negative predictive value of 89% were obtained in awake patients on the basis of the conventional HR criterion (positive if there was a > or = 20 bpm increase), whereas a sensitivity of 81% and a negative predictive value of 84% were obtained during sevoflurane anesthesia on the basis of the modified HR criterion (positive if there was a > or = 10 bpm increase). However, sensitivities, specificities, and positive and negative predictive values were all 100% on the basis of the SBP (positive if a > or = 15 mm Hg increase was recorded with an arterial line) and the T-wave criteria for both awake and anesthetized conditions. These results suggest that the SBP and T-wave criteria should be applied in awake and anesthetized elderly patients for detecting accidental intravascular injection of the epinephrine-containing test dose.