Abstract
Background Hypnotic depth but not haemodynamic responsiveness is
measured with EEG-based monitors. In this study we compared heart rate
variability (HRV) in unstimulated patients and stimulation-induced HRV at
different levels of anaesthesia. Methods A total of 95 ASA I or II patients
were randomly assigned to five groups (Group 1: BIS 45(5), remifentanil 1 ng
ml-1; Group 2: BIS 45(5), remifentanil 2 ng ml-1; Group 3: BIS 45(5),
remifentanil 4 ng ml-1; Group 4: BIS 30(5), remifentanil 2 ng ml-1; Group 5:
BIS 60(5), remifentanil 2 ng ml-1). A time- and frequency-domain analysis of
the RR interval (RRI) from the electrocardiogram was performed. HRV before
induction, before and after a 5 s tetanic stimulus of the ulnar nerve, and
before and after tracheal intubation was compared between groups, between
stimuli, and between responders to intubation [systolic arterial pressure
(SAP) increase >20 mm Hg, a maximal heart rate (HR) after intubation >90 min-1
or both] and non-responders (anova). Results Induction of anaesthesia
significantly lowered HR and HRV. Mean RRI before stimulation was higher in G3
than in G1, G2, and G4 (P < 0.001), whereas the other HRV parameters were
similar. Intubation induced a greater HRV response than tetanic stimulation.
The mean RRI after intubation was lower in G3 compared with the other groups
and the sd of the RRI after tetanic stimulation was lower in G3 compared with
G5. Otherwise, unstimulated HRV and stimulation-induced HRV were similar in
responders and non-responders. Conclusion HRV parameters discriminate between
awake and general anaesthesia, are different after tracheal intubation and a 5
s ulnar nerve stimulation, but do not discriminate between different levels
of haemodynamic responsiveness during surgical anaesthesia.
Original language | English |
---|---|
Pages (from-to) | 728-736 |
Journal | British Journal of Anaesthesia |
Volume | 98 |
Issue number | 6 |
DOIs | |
Publication status | Published - 2007 |
MoE publication type | A1 Journal article-refereed |
Keywords
- anaesthetics i.v., propofol
- analgesics opioid, remifentanil
- heart, heart rate variability
- monitoring, bispectral index
- Poincare´ analysis