Piglets were given IL-1 beta intravenously (Index I, n = 8) or intrathecally (Index II, n = 9) prior to apnea to test the hypothesis that IL-1 beta may prolong periods of apnea during sleep and infection. Apnea variables and the quality of autoresuscitation were recorded and compared to an apnea control group (Ctr. I, n = 7, apnea without injection of IL-1 beta) and a procedure control group (Ctr. II, n = 6, apnea after intratecally injected sterile water). Hypoxanthine (Hx) and xanthine (X) were analyzed in plasma, CSF and vitreous humor. The duration of apnea was significantly longer in the Index I - mean: 38, intraquartile range: 27-52 sec and Index II-group 26 (24-36) sec than in the Ctr. 1-12 (10-13) sec (p < 0.01) and the Ctr. II-group 14 (6-18) sec (p < 0.01). The number of respirations per 2 min following apnea in the Index I-group mean: 21, intraquartile range: 7-40 and was significantly less than in the Ctr. I-group 109 (39-150) (p < 0.01), while a similar tendency was found in the Index II-group 42 (27-55) (p = 0.06).
In conclusion: Intravenous and intrathecal injection of IL-1 beta prolong the duration of apnea and modifies autoresuscitation.