CJA
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Full Text (PDF)
Right arrow Submit a scholarly reply
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Graham, M.
Right arrow Articles by Mutch, W.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Graham, M.
Right arrow Articles by Mutch, W.

Canadian Journal of Anesthesia, Vol 43, 495-502, Copyright © 1996 by Canadian Anesthesiologists' Society

ARTICLES

Isoflurane and halothane impair both systolic and diastolic function in the newborn pig

MR Graham, DB Thiessen and WA Mutch
Department of Anaesthesia, University of Manitoba, Winnipeg, Canada. graham@bldghsc.lan1.umanitoba.ca

PURPOSE: Volatile anaesthetics have considerable effects on diastolic relaxation in the adult myocardium. We hypothesized that isoflurane (1) and halothane (H) may have even greater effects on diastolic function in the newborn, as the newborn heart has increased passive stiffness and altered calcium handling relative to the adult. Using a newborn pig model, we compared I and H at three clinically relevant concentrations with respect to both systolic and diastolic function. METHODS: Sixteen newborn pigs were randomized for study at control (background fentanyl 100 micrograms.kg-1.hr-1 and 0.5, 1.0 and 1.5 MAC of I (n = 8) or H (n = 8). Temperature, arterial blood gases, and LVEDP were controlled. Left ventricular pressure (LVP) was monitored continuously and LV anterior-posterior dimension was determined by using sonomicrometry crystals. Systolic function was assessed by peak positive dP/dT (dP/dTmax) and the slope of the end-systolic pressure-dimension (ESP-D) relationship. Diastolic relaxation was given by peak negative dP/dT (-dP/dTmax) and the time constant for ventricular relaxation (tau). Left ventricular stiffness was calculated from the slope of the end-diastolic pressure-dimension (EDP-D) relationship. RESULTS: At equal MAC concentrations, I and H were identical in effect for every variable studied. Systolic function was depressed at all anaesthetic concentrations. Control dP/dTmax (I:1815 +/- 561 (SD) mmHg.sec-1, H:1841 +/- 509) decreased to 832 +/- 341 with 1.5 MAC I and 691 +/- 127 with 1.5 MAC H (P < 0.05 vs control). ESP-D slope decreased from 62 +/- 31 mmHg.mm-1 at control to 15 +/- 11 with 1.5 MAC I and from 79 +/- 16 to 37 +/- 15 with 1.5 MAC H (P < 0.05 vs control). Diastolic function was affected only at higher MAC anaesthesia. Control tau increased from 18.0 +/- 6 msec to 29.1 +/- 7.5 with 1.5 MAC I and from 20.8 +/- 5.9 to 30.0 +/- 11.3 with 1.5 MAC H (P < 0.05). EDP-D slope was increased at both 1 and 1.5 MAC anaesthesia. EDP-D slope increased from 0.16 +/- 0.24 mmHg.mm-1 at control to 0.58 +/- 0.46 with I MAC I and from 0.16 +/- 11 to 0.50 +/- 0.35 with 1 MAC H. The -dP/dTmax decreased at every MAC level of anaesthesia. CONCLUSION: These combined systolic and diastolic effects help to explain the increased sensitivity of the newborn myocardium to volatile anaesthetics.


This article has been cited by other articles:


Home page
 Br J AnaesthHome page
M. Filipovic, I. Michaux, J. Wang, P. Hunziker, K. Skarvan, and M. Seeberger
Effects of sevoflurane and propofol on left ventricular diastolic function in patients with pre-existing diastolic dysfunction
Br. J. Anaesth., January 1, 2007; 98(1): 12 - 18.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1996 by the Canadian Anesthesiologists' Society.