七氟醚吸入诱导在小儿心脏手术麻醉中的应用

本文总结在大流量氧时吸入高浓度七氟醚在小儿先天性心脏病麻醉诱导中的应用。先天性心脏病患儿30例(紫绀型7例),心功能～级,平均年龄(2.5±1.3)岁,体重(11.6±3.12)kg。不给术前药,面罩吸入氧(5L/min) 8%七氟醚诱导。待疼痛反射消失后,开放静脉,停吸七氟醚,静脉给予阿托品、芬太尼、潘龙,2分钟后气管内插管。记录睫毛反射、疼痛反射消失时间、入室时、睫毛反射消失时、静脉给药前和气管插管后BP、HP、SpO2。观察诱导中患儿合作情况,有无呛咳、呕吐、呼吸抑制、喉痉挛、分泌物增多、躁动及心律失常。随机抽取7例非紫绀型小儿作为非紫绀组…     

紫绀型与非紫绀型先天性心脏病患儿吸人麻醉药血／气分配系数

目的测定并比较紫绀型与非紫绀型先天性心脏病患儿吸入麻醉药血／气分配系数(B／G),判断红细胞压积(Hct)对B／G的影响。方法紫绀型与非紫绀型先天性心脏病患儿各10例,平均年龄5岁,采桡动脉血10ml,用两次平衡法测定地氟醚、异氟醚和氟烷的B／G,并测定血浆总胆固醇、甘油三脂、白蛋白、球蛋白浓度和Hct,t检验比较两组间血液成分和吸入麻醉药B／G有无差别。结果紫绀型与非紫绀型先天性心脏病患儿Hct有显著差异(紫绀型为68．7％±11．1％,非紫绀型37．7％±2．9％,P<0．05);但两组间其他血浆成分和三种吸入麻醉药的B／G无差异(P>0．05)。结论Hct对B／G无影响,紫绀型与非紫绀型先天性心脏病患儿的B／G无显著性差异。     

七氟醚不同诱导方式对老年患者血流动力学的影响

目的 比较七氟醚逐渐增加吸入浓度诱导与高浓度快速吸入诱导两种诱导方式对老年患者血流动力学的影响.方法 全麻下择期手术的65岁以上老年患者40例,随机均分为逐渐增加吸入浓度诱导组(IS组)和高浓度快速吸入诱导组(RS组).IS组七氟醚初始吸入浓度为2%,每3次呼吸递增1%直至4%～5%;RS组吸入5%七氟醚.记录两组睫毛反射消失时间、脑电双频指数(BIS)降至60的时间及无意识肢动、呛咳、喉痉挛、屏气发生情况.分别于诱导前(T1)、吸入即刻(T2)、吸入后1 min(T3)、2 min(T4)、5 min(T5)、插管即刻(T6)和插管后1 min(T7)、5 min(T8)记录HR、SBP、DBP、MAP、SpO2及BIS等指标.结果 RS组2例发生呛咳、体动,IS组1例发生呛咳.RS组睫毛反射消失时间为(64.2±33.7)s,明显快于IS组的(138.0±82.7)s(P＜0.05).RS组BIS降至60的时间为(189.1±28.7)s,明显快于IS组的(232.2±36.8)s(P＜0.05).与T1时比较,RS组从T3后BIS开始下降,而IS组则从T5后才开始下降(P＜0.05).RS组T2～T4时BIS明显低于IS组(P＜0.05).结论 七氟醚吸入诱导对老年患者血流动力学无明显影响.逐渐增加吸入七氟醚浓度诱导时间略长于高浓度快速吸入诱导,吸入1 min后BIS明显下降.     

紫绀型与非紫绀型先天性心脏病患儿吸入麻醉药血／气分配系数

目的：测定并比较紫绀型与非紫绀型先天性心脏病患儿吸入麻醉药／气分配系数（Ｂ／Ｇ）,判断红细胞压积对Ｂ／Ｇ影响。方法：紫绀型与非紫绀型先天性心脏病患儿各１０例,平均年龄５岁,采桡动脉血１０ｍｌ,用两次平衡法测定地氟醚,异氟醺客氟烷的Ｂ／Ｇ,并测定血浆总胆固醇、甘油三脂,白蛋白、球蛋白浓度和Ｈｃｔ,ｔ检验比较两组间血液成分和吸入麻醉药Ｂ／Ｇ有无差别。结果：紫绀型与非紫绀型先天性心脏病患儿Ｈｃｔ有显著差     

七氟醚吸入麻醉在非住院患儿清创缝合术中的应用

目的观察七氟醚吸入麻醉在非住院患儿清创缝合术中的应用。方法年龄2~6岁ASAⅠ或Ⅱ级行清创缝合术患儿60例,随机均分为两组:七氟醚组(S组)及氯胺酮组(K组),分别采用面罩吸入七氟醚或肌肉注射氯胺酮进行麻醉诱导及维持。观察并记录两组患儿麻醉中MAP、HR、RR及SpO2的变化,记录意识消失、苏醒及麻醉恢复室(PACU)停留时间,观察并随访麻醉中及麻醉后的不良反应。结果 S组患儿术中MAP略有下降,HR无明显变化,而K组术中MAP升高、HR增快(P<0.05);S组患儿意识消失时间、苏醒时间及PACU停留时间明显短于K组(P<0.05);K组诱导期兴奋、术中体动及分泌物增加的病例数显著多于S组(P<0.05)。结论七氟醚吸入麻醉诱导迅速、维持平稳、苏醒彻底、循环呼吸影响小、不良反应发生率低、PACU停留时间短,可安全用于非住院患儿清创缝合手术麻醉。     

紫绀与非紫绀先心患儿动脉血与呼气末二氧化碳分压差的比较

目的本研究旨在分析紫绀型与非紫绀型先心患儿术中动脉血与呼气末二氧化碳分压的差值(Pa-ETCO2),评估过度通气对Pa-ETCO2的影响,分析七氟醚的浓度变化对Pa-ETCO2的影响。方法选择择期行心脏手术的患儿120例,男60例,女60例,年龄1个月~6岁,ASAⅡ或Ⅲ级,根据心脏内左向右或右向左分流按随机区组设计分为六组,每组20例:A1组,紫绀患儿接受0.5MAC七氟醚吸入麻醉;A2组,紫绀患儿接受1.0 MAC七氟醚吸入麻醉;B1组,非紫绀患儿接受0.5 MAC七氟醚吸入麻醉;B2组,非紫绀患儿接受1.0MAC七氟醚吸入麻醉;C1组,紫绀对照组,单纯静脉麻醉,不接受任何干预因素;C2组,非紫绀对照组,单纯静脉麻醉,不接受任何干预因素。所有患者开放动静脉后选择气管内插管全身麻醉。分别于切皮前、开胸行过度通气后(对照组不行过度通气)及关胸前5min记录患者的PETCO2、SpO2、PaCO2、SaO2、Hct及体温(鼻咽温和肛温)。结果切皮前,六组患儿Pa-ETCO2均大于正常值,且B1组明显小于A1组,B2组明显小于A2组,C2组明显小于C1组(P0.01)。与切皮前比较,过度通气后A1、A2、B1、B2组的Pa-ETCO2明显减小(P0.05或P0.01)。过度通气对非紫绀组的影响更明显。与切皮前比较,关胸前5min B1、B2、C2组的Pa-ETCO2明显增大(P0.01),而A1、A2、C1组的Pa-ETCO2明显减小(P0.05)。A1组与A2组,B1组与B2组各时点Pa-ETCO2差异均无统计学意义。结论紫绀型先心患儿的Pa-ETCO2明显大于非紫绀型先心患儿,因此,在紫绀型先心患儿中加强对动脉血气分析的校正是十分重要的。过度通气可以明显减小非紫绀型先心患儿中的Pa-ETCO2,但对紫绀型先心患儿不建议使用。七氟醚在一定范围内浓度的增加不会影响Pa-ETCO2。     

小儿七氟醚麻醉诱导方法的比较

目的 观察七氟醚诱导方法 在小儿腹腔镜短小手术中的应用效果.方法 将择期行腹腔镜腹股沟斜疝结扎术3～6岁患儿60例,随机均分为面罩肺活量吸入法诱导组(A组)与面罩潮气量吸入法诱导组(B组).记录睫毛反射消失时间、气管插管时间、血流动力学指标、拔管时间、意识恢复时间及不良反应.结果 A组睫毛反射消失时间(43.5±4.4)s,明显短于B组的(68.8±7.6)s(P<0.01);A组气管插管时间(3.5±0.7)min,明显短于B组的(6.7±1.4)min(P<0.01);两组拔管时间、意识恢复时间、不良反应的发生率差异无统计学意义.结论 两种七氟醚吸入诱导方法 均可获得良好的气管插管条件;面罩肺活量吸入诱导法起效更为迅速.     

七氟醚诱导对患儿镇静和循环的影响

目的 研究七氟醚吸入诱导对患儿循环、镇静深度的影响.方法 45例择期行腹部手术患儿随机均分为A、B、C组,分别吸入4%、6%、8%七氟醚麻醉诱导,观察体动消失时间、插管时间、诱导期不良反应和插管条件评分,记录入室时(T1)、诱导后30 s(T2)、插管前即刻(T3)、插管后即刻(T4)MAP、HR、SpO2和脑电双频指数(BIS).结果 C组体动消失时间和插管时间最快(P＜0.05),诱导后循环系统的抑制程度最大(P＜0.05),诱导中不良反应最多;插管前后A组的MAP波动最大(P＜0.05);A组插管条件评分最高.结论 七氟醚对患儿镇静程度和循环呈剂量相关性抑制,临床推荐吸入诱导浓度为6%.     

脑电双频指数用于七氟醚全麻喉罩自主通气实施乳腺癌根治术的临床意义

目的 探讨腩电双频指数(BIS)对七氟醚全麻喉罩自主通气下实施乳腺癌根治术的指导意义.方法 40例ASA Ⅰ或Ⅱ级择期乳腺癌根治术患者,随机均均分为BIS组和对照组.记录麻醉期间不同时点吸气末七氟醚浓度(CINSev)、呼气末七氟醚浓度(CETSev)、SBP、DBP、HR、SpO2、PETCO2、VT、每分钟通气量(VE)、RR、气道峰压(PPEAK),并取外周动脉血行血气分析.结果 两组均可获得满意的插管条件,BIS组置入喉罩前CETSev显著低于对照组(P<0.01),诱导时间显著长于对照组(P<0.05),诱导期间自主呼吸抑制发生率显著低于对照组(P<0.05),清醒时间和拔除喉罩时间均显著短于对照组(P<0.05).BIS组麻醉期间CETSev和CINSev均显著低于对照组(P<0.01).两组的SBP、DBP、HR及VT、VE、RR、PPEAK各时点变化差异无统计学意义.两组PaO2、PaCO2、碳酸氰根浓度(HCO3)、SaO2均维持正常;BIS组pH及PaCO2于插入喉罩后15 min及切皮时均显著低于对照组(P<0.01).结论 BIS指导七氟醚全麻喉罩自主通气,可减少七氟醚用量,自主呼吸维持较平稳.血流动力学稳定,呼吸功能及血气指标接近正常,全麻苏醒迅速.     

先天性膈疝患儿的麻醉管理53例

目的比较先天性膈疝(CDH)患儿七氟醚诱导维持与氯胺酮诱导复合异氟醚维持对呼吸循环及术后恢复的影响。方法 53例CDH患儿分为七氟醚诱导维持(S组,37例)与氯胺酮诱导复合异氟醚维持(K组,16例)。比较两组诱导前后HR、SBP、SpO2及麻醉苏醒时间;分析术前吸入不同的氧浓度与术后长时间(≥24 h)机械通气的相关性。结果与诱导前比较,两组诱导后SpO2均升高(P<0.05);S组诱导后HR减慢(P<0.01),但K组HR稳定;术后入ICU后的患儿中,S组诱导后及手术结束时HR减慢(P<0.01)。S组苏醒时间短于K组(P<0.01)。术前氧浓度需求≥33%的CDH患儿术后长时间机械通气的构成比高(P<0.01)。结论两种麻醉方案均能维持CDH患儿呼吸循环稳定,七氟醚能缩短患儿的苏醒时间;术前维持SpO2≥90%吸入的氧浓度可能是预测术后机械通气时间的指标。     

先天性心脏病患儿P_(ET)CO_2、TcPCO_2与PaCO_2监测的相关性

目的评估先天性心脏病患儿P_(ET)CO_2、经皮二氧化碳分压(TcPCO_2)与PaCO_2值的相关性。方法选择拟在体外循环下行先天性心脏病手术患儿80例,男42例,女38例,年龄1月~5岁,ASAⅡ~Ⅳ级,分为四组:紫绀型伴严重肺动脉高压组(N1组)、紫绀型不伴肺动脉高压组(N2组)、非紫绀型伴严重肺动脉高压或肺血流增加组(N3组)和非紫绀型伴轻度肺动脉高压或肺动脉压力正常组(N4组),每组20例。统一选取相同的麻醉方案,在手术开始前记录患儿的P_(ET)CO_2、TcPCO_2与PaCO_2值,计算P_(ET)CO_2、TcPCO_2与PaCO_2的差值,并进行相关性分析。结果 N1、N2、N3组P_(ET)CO_2与PaCO_2差值较大,N4组中相对较小;四组患儿TcPCO_2与PaCO_2差值都相对较小;N1、N2、N3组中TcPCO_2-PaCO_2值明显低于P_(ET)CO_2-PaCO_2值,N4组中TcPCO_2-PaCO_2值明显高于P_(ET)CO_2-PaCO_2值。P_(ET)CO_2与PaCO_2的相关性分析中,N1、N2、N3、N4组的R2分别为0.028、0.197、0.390、0.711(P0.05、0.02P0.05、P0.01、P0.01),在N1、N2组相关性较低,N3、N4组相关性较高;TcPCO_2与PaCO_2的相关性分析中,R2在N1、N2、N3、N4组分别为0.750、0.827、0.835、0.691(P0.01),各组均表现良好的相关性。结论小儿先天性心脏病无论是肺血流增加还是右向左分流均可使P_(ET)CO_2与PaCO_2的相关性较差,P_(ET)CO_2与PaCO_2仅在左向右分流的先天性心脏病患儿中表现较好的相关性;TcPCO_2与PaCO_2在小儿先天性心脏病监测中有良好的相关性,更适合为小儿先天性心脏病无创监测CO_2提供依据。     

紫绀型先天性心脏病病儿白细胞变形力的观察

目的 观察紫绀型先天性心脏病（先心病）病儿白细胞的变形力,探讨其微循环病理生理的变化。方法 ９例紫绀型先心病病儿为试验组与９例非紫绀型先心病病儿对照,分别检测其ＨＣＴ、高切及低切全血粘度、白细胞变形能力。结果 紫绀组病儿ＨＣＴ、全血粘度较对照组明显升高,白细胞变形力明显下降。结论 紫绀型先心病病儿有异常的血液流变学,而白细胞变形力的下降,进一步加重了这类病儿循环的障碍。     

Measurement of cerebral-oxygenation status when commencing cardiopulmonary bypass in pediatric open-heart surgery.

OBJECTIVE: We hypothesize that there is a difference in the cerebral-oxygenation status between cyanotic and non-cyanotic congenital heart disease when commencing a crystalloid-primed cardiopulmonary bypass (CPB). We tested this hypothesis by using near-infrared spectroscopy (NIRS). METHODS: Group 1 consisted of ten patients with non-cyanotic congenital heart diseases, including atrial septal (n=4) and ventricular septal defects (n=6), while group 2 consisted of ten patients with cyanotic congenital heart diseases, including tetralogy of Fallot (n=7) and univentricular heart (n=3). Changes in cerebral-oxygenated, deoxygenated and total hemoglobin concentrations were measured by NIRS just before and every minute for the first 10 min after commencing CPB. Arterial blood analysis was performed at those same time times. RESULTS: NIRS showed a rapid fall and plateauing of cerebral-oxygenated, deoxygenated and total hemoglobin in group 1. However, although group 2 showed a rapid fall and plateauing of cerebral-oxygenated hemoglobin, a rapid fall and continuous gradual decrease in cerebral-deoxygenated and total hemoglobin were also seen. Cerebral-deoxygenated and total hemoglobin decreased more markedly in group 2 than in group 1 (P<0.001, 0.01, respectively). CONCLUSION: NIRS revealed that the cerebral-oxygenated hemoglobin could be maintained at a similar level at the beginning of CPB in both groups. However, it showed a different distribution of cerebral-deoxygenated and total hemoglobin between the groups. An inadequate cerebral-oxygenation status may occur in the early phase of CPB in patients with cyanotic congenital heart diseases.     

紫绀与非紫绀型先天性心脏病患者PETCO2与PaCO2的相关性

目的探讨先天性心脏病患者PETCO2与PaCO2测定值的相关性.方法42例全身麻醉下手术患儿分为紫绀组、非紫绀组和对照组.结果三组PETCO2均无显著性差异.非紫绀组与对照组比较,PaCO2、Pa-ETCO2无显著性差异.紫绀组与对照组及非紫绀组比较,PaCO2与PaETCO2显著升高(P<0.01).三组PETCO2与PaCO2的线性相关系数分别为对照组0.96,非紫绀组0.86,紫绀组0.40.相关系数比较,非紫绀组与对照组无显著性差异(P>0.05),而紫绀组显著低于对照组及非紫绀组(P分别<0.01和<0.05).结论非紫绀型先天性心脏病不影响PETCO2测定值,而紫绀型先天性心脏病PETCO2显著低于非紫绀型先天性心脏病,不能准确反映PaCO2.     

超声用于先天性心脏病患儿大隐静脉穿刺的学习曲线

目的 本研究旨在使用累计和分析方法 (CUSUM)探讨超声用于传统穿刺经验丰富的麻醉科医师在外周静脉穿刺中学习曲线的变化.方法 选择先天性心脏病(CHD)患儿60例,男36例,女24例,年龄1～3岁,根据CHD类型分为两组:紫绀组和非紫绀组,每组30例.由一位穿刺经验丰富的麻醉科医师通过超声引导行大隐静脉穿刺.主要指标...     

The significance of baseline cerebral oxygen saturation in children undergoing congenital heart surgery

OBJECTIVES: Despite recent significant improvement in outcome, children undergoing surgery for correction of congenital heart defects have a persistent and troublesome mortality rate and incidence of neurologic complications. Recent data suggest that some congenital heart defects are associated with abnormal brain development and with low cerebral blood flow. We hypothesized that some children with congenital heart disease have an abnormally low baseline (preoperative) cerebral oxygen saturation (ScO2). METHODS: ScO2 was continuously recorded intraoperatively in 143 infants and children (age <18 years) undergoing repair of congenital heart defects on cardiopulmonary bypass. Baseline saturation was obtained prior to induction of anesthesia. Preoperative and postoperative saturations were correlated with the patient's physiology (cyanotic vs. acyanotic, presence of ventricular- or arterial-level left-to-right shunts) and outcome. RESULTS: Patient age ranged from 2 days to 17 years (median 8 months). Mean baseline ScO2 was 64%. Preoperative ScO2 was lower in infants with left to right shunt physiology (P < .01), but not in cyanotic infants without left-to-right shunts. Perioperative death was associated with baseline saturation less than 50%. CONCLUSIONS: Baseline ScO2 is lower in patients with left-to-right shunt physiology. Postoperative saturation is lower in patients with left-to-right shunt physiology and in cyanotic patients. Low baseline ScO2 predicts perioperative mortality in children with congenital heart disease. Measurement of ScO2 preoperatively will provide additional information for parent counseling, and preoperative optimization of ScO2 may improve outcome.     

Tidal breathing technique for induction of anaesthesia with high concentration of sevoflurane, isoflurane or halothane in infants undergoing cardiac surgery

Aims nduction characteristics of sevoflurane were compared with isoflurane and halothane in 45 acyanotic infants undergoing surgery for congenital heart disease. Methods Infants were randomized into three groups of 15 each. None of them received premedication. In group I induction was done with 8% sevoflurane in 100% oxygen, in group II with 5% isoflurane in 100% oxygen and in group III with 4% halothane in 100% oxygen. Induction time, intubation time, haemodynamic variables and side effects like coughing, laryngospasm, breatholding and excessive crying were noted. Results The mean induction time taken as loss of eyelash reflex was significantly lower in sevoflurane group (52.80±8.5 seconds) as compared to isoflurane (196.80±49.13 seconds) and halothane groups (168.72±9.1 seconds) (p value <0.001). The mean intubation time in sevoflurane group was 2.97±0.48 minutes followed by halothane group (5.10±2.9 minutes) and isoflurane group (6.70±1.77 minutes) (p value < 0.001). The incidence of coughing and laryngospasm was observed in 6% (1 in 15), each in sevoflurane and halothane groups and 20% (3 in 15) cases in isoflurane group. Haemodynamics were comparable in both sevoflurane and isoflurane groups. However in halothane group significant decrease in mean arterial pressure was observed. Conclusion Sevoflurane anaesthesia is a better alternative for induction in infants undergoing cardiac surgery as compared to isoflurane and halothane. (Ind J Thorac Cardiovasc Surg, 2001; 17:233-237)     

The safety and efficacy of sevoflurane anesthesia in infants and children with congenital heart disease

We tested the hypothesis that sevoflurane is a safer and more effective anesthetic than halothane during the induction and maintenance of anesthesia for infants and children with congenital heart disease undergoing cardiac surgery. With a background of fentanyl (5 microg/kg bolus, then 5 microg. kg(-1). h(-1)), the two inhaled anesthetics were directly compared in a randomized, double-blinded, open-label study involving 180 infants and children. Primary outcome variables included severe hypotension, bradycardia, and oxygen desaturation, defined as a 30% decrease in the resting mean arterial blood pressure or heart rate, or a 20% decrease in the resting arterial oxygen saturation, for at least 30 s. There were no differences in the incidence of these variables; however, patients receiving halothane experienced twice as many episodes of severe hypotension as those who received sevoflurane (P = 0.03). These recurrences of hypotension occurred despite an increased incidence of vasopressor use in the halothane-treated patients than in the sevoflurane-treated patients. Multivariate stepwise logistic regression demonstrated that patients less than 1 yr old were at increased risk for hypotension compared with older children (P = 0.0004), and patients with preoperative cyanosis were at increased risk for developing severe desaturation (P = 0.049). Sevoflurane may have hemodynamic advantages over halothane in infants and children with congenital heart disease. IMPLICATIONS: In infants and children with congenital heart disease, anesthesia with sevoflurane may result in fewer episodes of severe hypotension and less emergent drug use than anesthesia with halothane.     

Closed cardiovascular surgery in the first year of life--experience with 40 consecutive cases

A review of 40 consecutive infants with cardiovascular lesions requiring surgical intervention, without the use of the heart-lung machine, during a 3 year period is presented. Twenty-one patients were cyanotic and 19 were non-cyanotic preoperatively. In the former group, an operation was performed on an urgent or emergency basis in 8 patients (38%). In the latter group, 12 patients (63%) were in congestive heart failure and needed digitalis and diuretics preoperatively. The most frequent lesions among both groups were TOF and aortic coarctation, each being encountered in 6 patients, to be followed by d-TGA, PDA, and vascular ring, each being observed in 5 patients. The youngest patient was 8 hours old, had ectopia cordis associated with omphalocele, and the oldest was 12 months old, had a vascular ring. The lightest infant weighed 1.6 kg and had ligation of PDA at the age of one month. The most common surgical procedure was a systemic pulmonary artery shunt (13 patients), closure of PDA (5 patients), followed by repair of aortic coarctation using the LSA as a patch (6 patients), and division of vascular ring (5 patients). The operative M.R. was 15% in the whole series, 19% among the 21 cyanotic babies, 11% among the 19 non-cyanotic infants and 40% among the 10 patients operated in the first month of life. No death was noted among the 14 patients operated after the age of 6 months. Late mortality occurred in 4 patients giving a total mortality rate of 38% in this group of 21 infants with cyanotic malformations.(ABSTRACT TRUNCATED AT 250 WORDS)     

Relationship between invasive and noninvasive measurements of gas exchange in anesthetized infants and children

Minute ventilation (VE), tidal volume (VT), carbon dioxide elimination (VCO2), and end-tidal (PETCO2) and arterial CO2 tensions (PaCO2) were measured in 39 anesthetized infants and children with body weights ranging from 3.1 to 31 kg. Eighteen children had normal cardiopulmonary function, seven had acyanotic congenital heart disease, and 11 had cyanotic congenital heart disease. One child had left heart failure and pulmonary congestion, and two had severe parenchymal lung disease. To evaluate differences between pulmonary gas exchange calculated from PaCO2 versus PETCO2, dead space volume (VD) and alveolar ventilation (VA) based on a PaCO2 (VDa, VAa) as well as on PETCO2 (VDET, VAET) were performed, and correlations between PaCO2-PETCO2, VDa/VT-VDET/VT, and VAa-VAET were carried out. It was demonstrated that in normal children, as well as in those with acyanotic congenital heart disease, PETCO2 correlated closely with PaCO2 (r = 0.94, 0.98, respectively). In children with cyanotic congenital heart disease, however, correlation between PETCO2 and PaCO2 was relatively poor (r = 0.61). Mean values for PaCO2 were significantly higher than PETCO2 in the cyanotic children (P less than 0.01), resulting in significant underestimation of physiologic dead space (P less than 0.05) and significant overestimation of alveolar ventilation (P less than 0.01). In three patients with pulmonary disease, large differences between PaCO2 and PETCO2 were comparable with those observed in the children with cyanotic congenital heart disease.(ABSTRACT TRUNCATED AT 250 WORDS)