Low-dose remifentanil to suppress haemodynamic responses to noxious stimuli in cardiac surgery: a dose-finding study

• Published in: British journal of anaesthesia : BJA Vol. 98; no. 5; pp. 598 - 603
• Main Authors: Steinlechner, B., Dworschak, M., Birkenberg, B., Lang, T., Schiferer, A., Moritz, A., Mora, B., Rajek, A.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-05-2007; Oxford University Press; Oxford Publishing Limited (England)
• Subjects: Aged; anaesthetic techniques; anaesthetic techniques, i.v. infusion; analgesics opioid; analgesics opioid, remifentanil; Analgesics, Opioid - administration & dosage; Anesthesia; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Anesthetics, Intravenous - administration & dosage; Biological and medical sciences; bispectral index; Blood Pressure - drug effects; Cardiac Output - drug effects; Cardiac Surgical Procedures; cardiovascular anaesthesia; Dermatologic Surgical Procedures; Dose-Response Relationship, Drug; Drug Administration Schedule; Electrocardiography - drug effects; Female; Heart Rate - drug effects; Humans; i.v. infusion; Intubation, Intratracheal; Male; Medical sciences; Middle Aged; monitoring; monitoring, bispectral index; Monitoring, Intraoperative - methods; Piperidines - administration & dosage; Propofol - administration & dosage; remifentanil; Sternum - surgery; stress; Stress, Physiological - physiopathology; Stress, Physiological - prevention & control; monitoring, bispectral index; stress; cardiovascular anaesthesia; anaesthetic techniques, i.v. infusion; analgesics opioid, remifentanil; Agonist; bispectral index; stress; remifentanil; cardiovascular anaesthesia; monitoring; Low dose; μ Opioid receptor; Opiates; Narcotic analgesic; Remifentanil; Stress; i.v. infusion; analgesics opioid; Surgery; Anesthesia; Sedative; anaesthetic techniques; Monitoring
• ISSN: 0007-0912; 1471-6771
• DOI: 10.1093/bja/aem069

High-dose remifentanil (1–5 µg kg−1 min−1), commonly used for cardiac surgery, has been associated with muscle rigidity, hypotension, bradycardia, and reduced cardiac output. The aim of this study was to determine an optimal lower remifentanil dose, which should be accompanied by fewer adverse events, that still effectively suppresses haemodynamic responses to typical stressful stimuli (i.e. intubation, skin incision, and sternotomy).
Total i.v. anaesthesia consisted of a target-controlled propofol (2 µg ml−1) and a remifentanil infusion. Forty patients were allocated to receive either a constant infusion of remifentanil at 0.1 µg kg−1 min−1 or up-titrations to 0.2, 0.3, or 0.4 µg kg−1 min−1, respectively, 5 min before each stimulus. Subsequently, changes in heart rate and mean arterial blood pressure were recorded for 8 min. Increases exceeding 20% of baseline were considered to be of clinical relevance. Patients who exhibited these alterations were termed responders.
The number of responders was less with the two higher remifentanil dosages (P < 0.05) while propofol target doses could either be kept at the same level or even be reduced without affecting the plane of anaesthesia. Although single phenylephrine bolus had to be applied more frequently in these two groups (P < 0.05), no severe haemodynamic depression was observed.
Remifentanil at 0.3 and 0.4 µg kg−1 min−1 in combination with a target-controlled propofol infusion in the pre-bypass period is well tolerated. It appears to mitigate potentially hazardous haemodynamic responses from stressful stimuli equally well as higher doses when compared with data from the literature.