Forehead reflectance oximetry: a clinical comparison with conventional digit sensors during laparotomic and laparoscopic abdominal surgery.
OBJECTIVE
This study compared the performance of forehead reflectance and conventional pulse oximetry (SpO(2)) in mechanically ventilated, anesthetized patients undergoing major abdominal surgery with either laparoscopic or laparotomic techniques.


METHODS
SpO(2) 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. SpO(2) values measured with the two sensors were continuously recorded at 10-second intervals during the entire procedure, and then analyzed for consistency.


RESULTS
In group Laparotomy finger and forehead readings remained consistently similar during the study period; on the contrary, in group Laparoscopy forehead SpO(2) readings showed a much wider variability. The mean (95% Confidence Intervals) difference between finger and forehead SpO(2) 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 SpO(2) values increased from 0.2% (CI(95): -2.1% to +2.5%) during the first hour to 4.5% (CI(95): -2.5% to +11-5%) in the second hour (p = 0.0005), and 3.1% (CI(95): -2.4% to + 8.6%) in the third hour of surgery (p = 0.0005). Clinically relevant desaturation (decrease of SpO(2) < 89% for > or =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.


CONCLUSIONS
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.
Casati
Andrea
A
Department of Anesthesiology, Critical Care and Pain Medicine, University of Parma, Italy.
Squicciarini
Grazia
G
Baciarello
Marco
M
Putzu
Marta
M
Salvadori
Alessandra
A
Fanelli
Guido
G
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003082:Colectomy; D005385:Fingers / Q000098:blood supply; D005546:Forehead / Q000098:blood supply; D005743:Gastrectomy; D006801:Humans; D010535:Laparoscopy; D007813:Laparotomy; D008875:Middle Aged; D010092:Oximetry / Q000379:methods*; D011446:Prospective Studies
Intensive Care Med. 2001 Oct;27(10 ):1606-13
11685301
Intensive Care Med. 2004 Apr;30(4):709-13
14722632
J Clin Monit. 1988 Jul;4(3):223-6
3210070
Br J Anaesth. 1990 Oct;65(4):558-63
2248827
Respir Care. 2006 Jul;51(7):726-31
16800905
JAMA. 1986 Aug 22-29;256(8):1017-20
3735628
Respir Care. 2002 Jan;47(1):48-60
11749687
Anesth Analg. 2005 Mar;100(3):743-7, table of contents
15728063
J Cardiothorac Vasc Anesth. 2004 Aug;18(4):446-50
15365925
Respir Care Clin N Am. 2004 Sep;10 (3):359-67, vi-vii
15458733
J Clin Anesth. 1997 May;9(3):179-83
9172022
Anaesthesia. 2005 Jan;60(1):65-71
15601275
Anesthesiology. 1997 Jan;86(1):101-8
9009945
J Clin Monit. 1995 Jul;11(4):237-44
7561997
Acta Anaesthesiol Scand. 2002 Mar;46(3):303-8
11939922
Minerva Anestesiol. 2002 Apr;68(4):236-9
12024089
Crit Care Med. 2002 Nov;30(11):2501-8
12441761
J Clin Monit. 1995 Jul;11(4):253-6
7561999
Anesthesiology. 2006 Dec;105(6):1111-6
17122573