Postoperative Oxygen Saturation in Patients Receiving Spinal Anesthesia

Abstract

Background : Postoperative hypoxemia is common in patients receiving general anesthesia and oxygen is  given routinely during postoperative period  but no data about postoperative  oxygen saturation (SpO₂) in patients receiving spinal anesthesia has been reported.

Design : Descriptive study.

Setting : Srinagarind Hospital, Faculty of Medicine, Khon Kaen University.

Subjects : The study was done in 154 patients, ASA class I or II receiving spinal anesthesia with 5% heavy lidocaine or 0.5% bupivacaine. There were 99 male and 55 female patients with average age of 38.16 ± 18.42 years . the average body weight was 56.99 ± 10.63 kgs. The hematocrit value was 37.34 ± 5.44% the level of sensory block was T8. 94 ± 2.65 The operating time was 74.20 ±37.13 minutes.

Intervention : N.A.

Measurements : SpO₂ was recorded at mimute 0,5,10,15,20,25 and  30 were 98.11, 98.25, 98.47, 98.62, 98.73, 98.75 and 98.89% respectively. SpO₂ at minute 0, 5 and 10 in patients age more than 60 were significantly less than those with age under 40 and 60. At minute 15 and 20 SpO₂ in age group over 60 were significantly less than age group under 40. SpO₂ at minute 30 in patients with weight more than 60 and between 60 and 80 kgs significantly. The patients with pulse rate more than 100 the differences are statistically but not clinically significant.

Conclusion : The average SpO₂ in this study was 98%. Hypoxemia was found only 0.65%. the patients in age group over 60, weight over 80 kgs and pulse rate over 100/minute tended to have significantly lower  SpO₂. The level of sensory block, local anesthetic agents, time of operation, hematocrit value and blood pressure had no effect on SpO₂.

Key Words : Oxygen saturation, postoperative spinal anesthesia, oxygen saturation