Analysis of the effects of the alveolar recruitment maneuver on blood oxygenation during bariatric surgery.
BACKGROUND AND METHDS: Alveolar recruitment maneuver (ARM) is indicated in the treatment of intraoperative atelectasis. The objective of the present study was to compare two techniques of ARM using the response of the PaO2/FiO2 ratio and [PaO2 + PaCO2] in patients with grade III obesity.


METHODS
This was an open prospective study with adult patients with grade III obesity who underwent bariatric surgery under volume-controlled mechanical ventilation with positive end-expiratory pressure (PEEP) of 5 cmH2O, divided in three groups: G CONT: PEEP of 5 cmH2O; G ARM10/15/20 after suture of the aponeurosis: progressive increase in PEEP to 10, 15, and 20 cmH2O with a 40-second pause and maintaining each level of PEEP for 2 minutes; and G ARM30 after suture of the aponeurosis: sudden increase in PEEP to 30 cmH2O with a 40-second pause and maintaining a PEEP of 30 for 2 minutes. Heart rate, mean arterial pressure, systolic and diastolic blood pressure, mean (P AW) and plateau (P PLAT) airways pressure, partial pressure of oxygen (PaO2), partial pressure of carbon dioxide (PaCO2), PaO2/FiO2 ratio (inspired fraction of oxygen), and [PaO2 + PaCO2] were analyzed.


RESULTS
The following parameters showed statistically significant differences among the study groups: P PLAT, P AW, PaO2, PaO2/FiO2 ratio, and [PaO2 + PaCO2] (p < 0.0001). Comparing the groups two by two, the following parameters showed statistically significant differences: for P PLAT and P AW: G CONT x G2ARM10/15/20 and G CONT x G ARM30; and for PaO2/FiO2 ratio and [PaO2 + PaCO2]: G CONT x G ARM30.


CONCLUSIONS
Alveolar recruitment maneuver with sudden increase of PEEP to 30 cmH2O showed a better response of the PaO2/FiO2 ratio.
de Souza
Alda Paiva
AP
Departamento de Recuperação Pós-anestésica, UTI do Departamento de Cirurgia e UTI - Neurocirurgia da ISCMSP.
Buschpigel
Márcia
M
Mathias
Ligia Andrade Silva Telles
LA
Malheiros
Carlos Alberto
CA
Alves
Vera Lucia dos Santos
VL
D000328:Adult; D050110:Bariatric Surgery; D001784:Blood Gas Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000601:surgery*; D010100:Oxygen / Q000097:blood*; D011175:Positive-Pressure Respiration / Q000379:methods*; D011446:Prospective Studies; D001261:Pulmonary Atelectasis / Q000628:therapy*
D010100:Oxygen