Patient Cooperation During General Anesthesia for Combined Carotid and Coronary Artery Surgery

Abstract

To the Editor: Patients with concomitant carotid and coronary artery disease present a surgical dilemma, and the literature regarding their management is controversial. In these patients, intraoperative cerebrovascular accidents, difficult to detect during surgery, are relatively common1,2 and are associated with high mortality. We read with interest the article by Turkoz et al3 who assessed, in a case series (44 patients), the patient’s neurologic status after carotid endarterectomy (CEA) by means of a wake-up test to identify stroke before the beginning of coronary artery bypass graft surgery. The authors suggested that such evaluation may make a contribution to increasing the safety of combined surgical procedures in patients with coronary and carotid artery disease. Conversely, we describe an anesthetic technique, performed in an 82-year-old man undergoing combined carotid and coronary artery surgery, that allowed the clinical monitoring of cerebral function during the whole time of carotid artery clamping. General anesthesia was induced, after preoxygenation, with remifentanil, 1 g/kg, and propofol, 0.5 mg/kg, followed by additional boluses of 10 mg every 10 seconds until abolition of response to verbal commands and loss of the eyelash reflex. Neuromuscular blockade was achieved with cisatracurium, 0.2 mg/kg. The patient’s trachea was intubated, and anesthesia was maintained with propofol, 2.5 mg/kg/h, and remifentanil, 0.25 g/kg/min. Ventilation was accomplished by synchronized volume-controlled ventilation (Primus apparatus; Drager, Lubeck, Germany) and was adjusted to maintain an end-tidal carbon dioxide concentration between 4.5 and 5.5 kPa. The surgical strategy, arranged by both vascular and cardiac surgeons, was based on performing CEA before cardiac surgery. In order to perform neurologic monitoring during CEA, the residual neuromuscular block was antagonized with neostigmine, 35 g/kg, and atropine, 20 g/kg, and when the train-of-4 showed complete reversal, the propofol infusion was stopped. The rate of remifentanil infusion was gradually decreased at 3-minute intervals of 0.03 g/kg/min , from 0.25 g/kg/min to 0.12 g/kg/min. At this infusion rate, the patient remained calm and tolerated the surgical maneuvers and the tracheal tube without coughing, and was still able to obey verbal commands. In this setting, clinical neurologic monitoring was feasible with the patient quiet and stable. During the lightening of anesthesia, heart rate increased from 47 to 60 beats/min and systolic arterial pressure from 130 to 170 mmHg. No neurovegetative signs or motor responses to nociceptive stimulation were detectable. The patient was asked to tighten the hand of the anesthesiologist before carotid artery clamping and then every minute during the 35 minutes of clamping. Thus, close, continuous neurologic monitoring was performed, and the development of early neurologic deficits was clearly excluded. General anesthesia was then resumed, and coronary artery bypass graft surgery was performed immediately afterwards. The day after surgery, the patient was interviewed to determine what he could remember of the operation. He had no explicit memory of any event, pain, or discomfort during surgery and said that he was satisfied with anesthesia. The postoperative course was uneventful, and the patient was discharged from the hospital without complications 8 days later. To our knowledge, this is the first report in which conscious sedation and analgesia were used during combined carotid and coronary artery surgery. Our method was different from the technique described by Turkoz et al, 3 who assessed the neurologic status only at the end of the CEA; we performed close neurologic monitoring during the whole period of carotid artery clamping by lightening the hypnotic component of general anesthesia. In our opinion, this approach, besides permitting clinical neurologic monitoring during surgery (ie, alter the shunt strategy and change the surgical plan), may offer the advantage of hemodynamic stability in the patient with coronary artery disease. Madi-Jebara et al 4 described a staged anesthetic approach characterized by the combination of regional anesthesia for CEA followed immediately by general anesthesia for coronary artery bypass graft surgery. Our technique appears simpler and more reliable. Furthermore, it allows the absolute control of ventilatory pattern and the easy, prompt, and safe use of general anesthesia whenever required during the operation.