The primary physiologic function of platelets is to facilitate hemostasisby aggregation. Volatile anesthetics have been reported to decrease platelet aggregation in vivo and in vitro.
The aim of this study was to investigate the hematologic effectsof the anesthetics isoflurane, sevoflurane, and desflurane on hemoglobin (Hb), hematocrit (Hct), platelet count, activated partial thromboplastin time (aPTT), prothrombin time (PT), international normalized ratio (INR), and platelet aggregation after minor surgery.
Patients aged 20 to 60 years who were scheduled to undergominor surgery and American Society of Anesthesiologists physical status P1 or P2 (healthy or mild systemic disease) were randomized to 1 of 3 groups: 1 minimum alveolar concentration (MAC) of isoflurane, sevoflurane, or desflurane. None of the patients received premedication. Anesthesia was induced using IV thiopental 5 to 6 mg/kg, fentanyl 1 to 2 μg/kg, and vecuronium 0.1 mg/kg, and maintained with 1 MAC of isoflurane, sevoflurane, or desflurane in 66% nitrous oxide and 33% oxygen. Vecuronium 0.03 mg/kg was given when necessary for muscle relaxation. All patients were monitored throughout surgery; isotonic saline was given at a rate of 5 mL/kg · h. Hematologic studies were performed preoperatively, 15 minutes after intubation, and 1 hour after the end of surgery. Platelet aggregation tests were performed in a laboratory using a platelet function analyzer (PFA), collagen/epinephrine PFA test cartridges, collagen/adenosine diphosphate PFA test cartridges, and PFA trigger solution.
This prospective, randomized, single-blind, in vivo study was conducted at Gevher Nesibe Teaching Hospital, Erciyes University, Kayseri, Turkey. Thirty patients (15 men, 15 women) were randomized to the 3 treatment groups (each, n = 10). Hb, Hct, platelet count, aPTT, PT, and INR were statistically similar between all 3 groups. The measured parameters were not significantly different between the isoflurane and desflurane groups at any time point. However, in the sevoflurane group, mean (5D) platelet aggregation was significantly delayed 15 minutes after intubation and 1 hour after surgery compared with the preoperative values (collagen/epinephrine, 81.70 [9.85] seconds vs 196.20 [27.84] seconds and 115.40 [25.80] seconds; both, P < 0.05).
In this study of the effects of isoflurane, sevoflurane, and desflurane in patients undergoing minor surgery, clinically relevant antithrombotic effects were observed 15 minutes after intubation with all 3 drugs, although the effects in patients receiving sevoflurane were significantly greater compared with those in patients receiving isoflurane and desflurane. The antithrombotic effects of isoflurane and desflurane were not continued at 1 hour after surgery; however, the inhibitory effects of sevoflurane on platelet function were continued at 1 hour after surgery but were significantly decreased from levels found at 15 minutes after intubation.