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Anesthesia technique for OPCAB surgery
SOP » Anaesthesia protocol » Anesthesia technique for OPCAB surgery
Last modified on Tue 15 Jul 2014

General anesthesia is still the best type of anesthesia used for off-pump coronary artery surgery. Thoracic epidural anesthesia in a wake patient has also been used for this type of surgery but there are no convincing clinical trials published until now (1). ”General anesthesia" covers several aspects that require close control in the pre- intra- and postoperative care of surgical patients. It consists not only of an adequate induction and maintenance of unconsciousness but also of the continuous titration to proper (i.e. adjusted to the type of surgery) levels of analgesia, amnesia, neuromuscular blockade and stress control.
For each of these separate pharmacodynamic goals the modern anesthesiologist uses a host of different drugs. Current developments in the field have produced pharmacological agents with favorable pharmacokinetic properties allowing a fast onset and offset of their effects.
For the anesthetic management of patients undergoing OPCAB surgery there is no reason to select "special" drugs. The only evolution that has occurred over the past few years is the gradual omission of the "high dose opioid" technique. The use of high dose opioids to obtain unconsciousness offers great hemodynamic stability at the expense of prolonged postoperative respiratory depression.

The novel ultra-short acting opioid remifentanil is the only exception to this. Recent studies have shown that the addition of low doses of a hypnotic drug safeguards the patient from experiencing unintentional awareness. Although it is clear that several combinations of drugs are being used with success in a variety of medical centers we present our own technique here as a working example :

Premedication

  • Lorazepam 0,04-0,05 mg/kg sublingual

Induction

  • Etomidate 0,3 mg/kg IV OR Midazolam 0.05 mg/kg IV
  • Sufentanil 0.5 - 1 µg/kg IV
  • Propofol TCI 1 µg/ml IV
  • Pancuronium 0,1 mg/kg IV OR Cisatracurium 0,15-0,2 mg/kg IV

Maintenance

  • Propofol TCI 1-2 µg/ml IV
  • Sufentanil top up to 2-3 µg / kg at sternotomy
  • Sufentanil 5-8 µg / kg cumulative dose for entire procedure
  • Cisatracurium per 0,05 mg/kg every 45 – 60 min
    Low dose volatile anesthetic like sevoflurane

Alternative techniques include the use of remifentanil :

  • Induction at 1-2 µg/kg bolus
  • Maintenance 0.5- 1 µg/kg/min continuous infusion

The important matter is probably not which drugs are being used to control anesthesia but the way they are used (and this has been shown over and over again in our scientific literature for classic cardiac surgery/anesthesia).

The incidence of intra-operative awareness is highest in cardiac surgery. For this reason we currently premedicate mostly all our patients with lorazepam sublingually. Some of our faculty members prefer to use low dose of propofol TCI 1-2 µg/ml IV. Since hemodynamic instability should be treated with cardiovascular drugs and not by decreasing the dose of anesthetics. To avoid the latter reflex we recommend to use Bispectral index monitoring, particularly in the first phase of the OPCAB learning curve.