Hypoxemic resuscitation in newborn piglets: recovery of somatosensory evoked potentials, hypoxanthine, and acid-base balance.
We tested the hypothesis that hypoxic newborn piglets can be successfully resuscitated with lower O2 concentrations than 21%. Severely hypoxic, 2-4-d-old, anesthetized piglets were randomly divided into five resuscitation groups: 21% O2 (n = 10), 18% O2 (n = 9), 15% O2 (n = 9), 12% O2 (n = 8), all normoventilated, and a hypoventilated 21% O2 group (PaCO2; 7.0-8.0 kPa, n = 9). Base excess (BE) reached -20 +/- 1 mmol/L at the end of hypoxia. After 3 h of resuscitation, BE had risen to -4 +/- 1 mmol/L in the 21% O2, 18% O2, and hypoventilated groups, but was -10 +/- 2 mmol/L in the 15% O2 group (p < 0.05 versus 21% O2 group) and -22 +/- 2 mmol/L in the 12% O2 group (p < 0.05 versus 21% O2 group). Four animals died during resuscitation, all allocated to the 12% O2 group (p < 0.05 versus 21% O2 group). Somatosensory evoked potentials (SEPs) recovered in 39 of 45 piglets, and remained present during resuscitation in all except the 12% O2 group. SEP recovered initially even in six of eight animals in the 12% O2 group, but disappeared again in all later during resuscitation. The SEP amplitude recovered to levels not significantly different from the 21% O2 group in all groups except the 12% O2 group. Plasma hypoxanthine concentrations and extracellular hypoxanthine concentrations in the striatum decreased during resuscitation to levels not significantly different from the 21% O2 group in all but the 12% O2 group (p < 0.05 versus 21% O2 group). In conclusion, severely hypoxic newborn piglets were resuscitated as efficiently with both hypoventilation and 18% O2 as with 21% O2.
Feet
B A
BA
Department of Pediatric Research, Institute for Surgical Research, National Hospital, Oslo, Norway.
Medbö
S
S
Rootwelt
T
T
Ganes
T
T
Saugstad
O D
OD
D000136:Acid-Base Equilibrium / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D001794:Blood Pressure; D002245:Carbon Dioxide / Q000097:blood; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D019271:Hypoxanthine / Q000097:blood*; D000860:Hypoxia / Q000503:physiopathology*; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D012151:Resuscitation; D013552:Swine; D013997:Time Factors
D002245:Carbon Dioxide; D019271:Hypoxanthine; D010100:Oxygen