Abstracts of Posters Presented at the International Anesthesia Research Society; 72nd Clinical and Scientific Congress; Orlando, FL; March 7-11, 1998: Cardiovascular Anesthesia
Introduction: The use of the laryngeal mask airway (LMA) is associated with a blunted response in arterial blood pressure and heart rate when compared to a comparable group of patients undergoing direct laryngoscopy and endotracheal intubation (ET) . The high incidence of coronary artery disease (CAD) in patients requiring CEA makes intra-operative hypertensive and tachycardic episodes potentially serious since preoperative CAD increases the frequency of postoperative myocardial infarction . Thus, techniques that minimize intraoperative hypertension and tachycardia may be advantageous during CEA.
Methods: After IRB approval and patient consent, 30 adult males scheduled for CEA were randomized into an LMA group or ET group (n=15, each group). Mean arterial blood pressure (MABP), heart rate (HR) end-tidal isoflurane, length of case, and episodes requiring vasopressor and or antihypertensive therapy were recorded.
Results: Patient demographics and isoflurane requirements (MAC-hours) were similar between groups. The mean number of hypertensive and tachycardia episodes and frequency of therapeutic intervention (anti-hypertensive, primarily labetolol) was significantly (p<.05) higher in the ET group when compared to the LMA group (Figure 1).
Discussion: These results demonstrate that patients managed with LMA for CEA have a lower number of intraoperative episodes of hypertension and tachycardia when compared to a comparable group managed with ET. LMA airway management may have an advantage over ET during CEA in appropriately selected patients.
1. Anaesthesia 1989;44:551-4.
2. Anesthesiology 1983;59:499-505.