Neonatal patterns of breathing after cesarean section with or without epidural fentanyl

The pattern of breathing and lung mechanics were evaluated during the first 7 h of life in full-term healthy newborns delivered by cesarean section with bupivacaine epidural anesthesia, without (group 1) or with the addition of 100 micrograms of fentanyl (group 2). Respiration and oxyhemoglobin saturation (SpO2) were measured with calibrated inductive plethysmography and pulse oximetry, respectively, and recorded from 60-420 min following birth. Compliance of respiratory system (CRS) was measured using a multiple occlusion technique at 60 and 420 min. Pattern of breathing was compared during period I (60-240 min) and II (240-420 min) with the following results: 1) the number of apnea spells was similar in both groups during both periods; 2) in both groups, from period I to period II a significant decrease in apnea duration was observed (7.6 +/- 0.7 s-4.1 +/- 0.5 s in group 1 and 6.7 +/- 1.2 s-5.1 +/- 1.0 s in group 2, respectively (P less than 0.05); 3) respiratory rate (RR) and minute ventilation (VE) were similar in both groups during both study periods; and 4) both RR and VE significantly decreased in the two groups from period I to period II (i.e., 59 +/- 5-46 +/- 2 breath per min-1 and 313 +/- 60-248 +/- 24 ml.kg-1.min-1 in group 1, and 60 +/- 2-51 +/- 1 breath.min-1 and 318 +/- 12-290 +/- 12 ml.kg-1.min-1 in group 2, respectively; P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)