Malviya S, Swartz J, Lerman J
Department of Anaesthesia, Hospital for Sick Children, University of Toronto, Ontario, Canada.
Anesthesiology. 1993 Jun;78(6):1076-81. doi: 10.1097/00000542-199306000-00009.
Preterm and ex-preterm infants are at risk for life-threatening apnea after general anesthesia. The authors attempted to define the postconceptual age beyond which apnea is less likely to occur and to identify the factors that predispose to postanesthetic apnea.
Ninety-one infants younger than 60 weeks postconceptual age undergoing 101 general anesthetics were prospectively studied. All infants were admitted to the hospital for cardiorespiratory monitoring overnight. The presence of coexistent medical conditions that could influence the incidence of apnea was determined by a review of current and previous medical records and by history.
Of 38 procedures performed in 35 infants younger than 44 weeks postconceptual age, 10 (26.3%) procedures in 9 infants were associated with postanesthetic apnea. In eight of these, apnea did not resolve spontaneously: four infants required stimulation, and four required continuous positive airway pressure by face mask. Apnea occurred after 2 of 63 procedures performed in infants 44 weeks postconceptual age or older. Both episodes occurred in one patient who had neurologic disease. Of the remaining 61 procedures in the latter age group, 7 were associated with episodes of bradycardia (lowest heart rate was 79 beats/min) postoperatively without apnea. These episodes lasted up to 5 s, were not associated with apnea or cyanosis, and resolved spontaneously in all cases. All infants with postanesthetic apnea and/or bradycardia experienced their first episode within 12 h after surgery.
Ex-preterm infants younger than 44 weeks postconceptual age are at greater risk for apnea after general anesthesia than are infants older than 44 weeks postconceptual age. Based on these results, the maximum long-run risk of postanesthetic apnea in preterm infants older than 44 weeks postconceptual age is 5% with 95% confidence.
早产及曾经早产的婴儿在全身麻醉后有发生危及生命的呼吸暂停的风险。作者试图确定孕龄超过多少周后呼吸暂停发生的可能性较小，并找出易导致麻醉后呼吸暂停的因素。
对91例孕龄小于60周的婴儿进行了101次全身麻醉，并进行前瞻性研究。所有婴儿均入院接受过夜心肺监测。通过查阅当前及既往病历和病史来确定可能影响呼吸暂停发生率的并存疾病情况。
在孕龄小于44周的35例婴儿所进行的38例手术中，9例婴儿的10例（26.3%）手术与麻醉后呼吸暂停相关。其中8例呼吸暂停未自行缓解：4例婴儿需要刺激，4例需要面罩持续气道正压通气。孕龄44周及以上婴儿所进行的63例手术中有2例发生呼吸暂停。这两例均发生在一名患有神经系统疾病的患者身上。在该年龄组其余61例手术中，7例与术后心动过缓发作（最低心率为79次/分钟）相关，但无呼吸暂停。这些发作持续长达5秒，与呼吸暂停或发绀无关，且所有病例均自行缓解。所有发生麻醉后呼吸暂停和/或心动过缓的婴儿在术后12小时内首次发作。
孕龄小于44周的曾经早产的婴儿比孕龄大于44周的婴儿在全身麻醉后发生呼吸暂停的风险更高。基于这些结果，孕龄大于44周的早产婴儿麻醉后呼吸暂停的最大长期风险为5%，95%置信区间。
