Forehead Reflectance Oximetry: A Clinical Comparison with Conventional Digit Sensors during Laparotomic and Laparoscopic Abdominal Surgery
- 124 Downloads
This study compared the performance of forehead reflectance and conventional pulse oximetry (SpO2) in mechanically ventilated, anesthetized patients undergoing major abdominal surgery with either laparoscopic or laparotomic techniques.
SpO2 was continuously measured both with a forehead reflectance and a conventional digit sensor in 20 ASA physical status I–III, anesthetized patients undergoing either a laparotomic (group Laparotomy, n = 10) or laparoscopic (group Laparoscopy, n = 10) major abdominal surgery. SpO2 values measured with the two sensors were continuously recorded at 10-second intervals during the entire procedure, and then analyzed for consistency.
In group Laparotomy finger and forehead readings remained consistently similar during the study period; on the contrary, in group Laparoscopy forehead SpO2 readings showed a much wider variability. The mean (95% Confidence Intervals) difference between finger and forehead SpO2 readings was 2.0% (−1.3% to +6.0%) in group Laparotomy and 2.5% (−3.5% to +8.4%) in group Laparoscopy (p = 0.001); however, in group Laparoscopy the mean difference between digit and forehead SpO2 values increased from 0.2% (CI95: −2.1% to +2.5%) during the first hour to 4.5% (CI95: −2.5% to +11–5%) in the second hour (p = 0.0005), and 3.1% (CI95: −2.4% to + 8.6%) in the third hour of surgery (p = 0.0005). Clinically relevant desaturation (decrease of SpO2 < 89% for ≥30 s) detected with the forehead sensor in the Laparoscopy group was significantly more frequent and longer lasting than with conventional digit sensor. No differences were observed in group Laparotomy.
Forehead reflectance oximetry is as accurate as conventional digit based oximetry in mechanically ventilated patients undergoing laparotomic surgery in the supine position, but is significantly influenced by patient positioning and pneumoperitoneum during laparoscopic surgery.
Keywordspulse oximetry reflectance oximetry mechanical ventilation abdominal surgery laparotomic laparoscopic
Unable to display preview. Download preview PDF.
The study was entirely supported by the University of Parma and Azienda Ospedaliera di Parma. The Authors thank Tyco Healthcare, Milano, Italy for supplying the Score Analysis Software and both forehead and digit sensors free of charge.
- 6.Hertzman AB, Roth LW (1942) The absence of vasoconstrictor reflexes in the forehead circulation: effects of cold. Am J Physiol 136: 6092–6097Google Scholar