Abstract: Background　Severe pneumonia in children，which is often accompanied by organ damage，needing mechanical ventilation.Therefore，early and effective intra-abdominal pressure（IAP） monitoring is the key to rescuing children with critical respiratory illness，but there are few reports.Objective　To evaluate the role of IAP under different types of respiratory support in the rescue and prognostic prediction of severe pneumonia in children，providing reliable evidence for organ protection in treating this disease.Methods　150 children with severe pneumonia who were admitted to the ICU，Hebei Children's Hospital from December 2015 to April 2018 were enrolled.Clinical data were collected，including demographic factors（gender，age and so on），blood test parameters 〔procalcitonin（PCT），C-reactive protein（CRP），oxygen saturation（SaO2），arterial partial pressure of oxygen（PaO2），arterial partial pressure of carbon dioxide（PaCO2）〕，symptomatic treatment，and type of respiratory support 〔nasal cannula oxygen therapy（group A，n=50），continuous positive airway pressure（CPAP）（group B，n=50）and mechanical ventilation（group C，n=50）〕，and IAP measured at 24 and 72 hours after admission.Subgroup comparisons of ventilator parameters〔positive end expiratory pressure，peak inspiratory pressure（PIP），fraction of inspired oxygen（FiO2）〕 and incidence of MODS and ACS were performed between those with 72 hours post-admission increased IAP（n=32）and normal IAP（n=18）in group C 〔increased and normal IAP were defined as >10 mm Hg（1 mm Hg=0.133 kPa）and ≤10 mm Hg，respectively〕.Results　Group B had a younger average age than other groups（P<0.05）.Group C had higher average levels of admission CRP，PCT and PaCO2 and lower average levels of admission SaO2 and PaO2 than other groups（P<0.05）.There was no significant difference in average IAP levels among the three groups on admission（P>0.05）.There were significant differences in average IAP levels between the three groups at 24 and 72 hours of respiratory support（P<0.05）.In particular，group C had higher average IAP level at 24 or 72 hours of respiratory support than other groups（P<0.05）.There were significant differences in average IAP levels between groups B and C at different time points（P<0.05）.The average IAP levels in group C measured at admission，24 and 72 hours of respiratory support showed a successive increase trend（P<0.05）.In group C，those with 72 hours post-admission increased IAP had higher average PIP and FiO2 and higher incidence of MODS than those with normal IAP（P<0.05）.Conclusion　IAP may be influenced by the level of airway pressure caused by the three types of respiratory support.PIP and FiO2 under mechanical ventilation may have a significant impact on IAP，which suggests that these two parameters should be lowered as soon as possible in clinical treatment to reduce iatrogenic damage.Dynamic monitoring of IAP in children with pneumonia has a predictive value for the evolution of disease and the degree of organ damage in severely ill children.

Key words: Severe pneumonia, Child, Mechanical ventilation, Intra-abdominal pressure, Procalcitonin, C-reactive protein

摘要： 背景　儿童重症肺炎常同时伴随脏器损害，需要机械通气治疗。因此，进行早期有效易行的腹内压（IAP）监测是指导儿童呼吸道危重症抢救治疗的关键，但相关报道较少。目的　评估不同通气方式IAP监测在小儿重症肺炎抢救中的作用及预后评估，为脏器保护治疗等方面提供可靠依据。方法　选取2015年12月—2018年4月入住河北省儿童医院ICU的150例重症肺炎患儿为研究对象，入院后记录患儿的性别、年龄等一般资料信息，并抽血检测降钙素原（PCT）、C反应蛋白（CRP）、氧饱和度（SaO2）、动脉血氧分压（PaO2）、动脉血二氧化碳分压（PaCO2）；给予相应处理及适当的氧疗，并根据氧疗通气方式分为A组（鼻导管吸氧）、B组〔经鼻持续正压通气（CPAP）〕及C组（机械通气），每组50例。监测入院后24 h、72 h 3组IAP。根据入院72 h IAP，将C组分为IAP增高亚组（>10 mm Hg，1 mm Hg=0.133 kPa，32例）及IAP正常亚组（≤10 mm Hg，18例），记录患儿呼吸机参数：呼气末正压（PEEP）、峰压（PIP）、氧浓度（FiO2）及多器官功能障碍综合征（MODS）、腹腔间隙综合征（ACS）发生率，并比较两组间有无差异。结果　A、C组年龄低于B组，入院时C组CRP、PCT、PaCO2高于A组与B组，SaO2、PaO2低于A组与B组（P<0.05）。3组患儿入院时IAP水平比较，差异无统计学意义（P>0.05）；3组患儿通气24 h及通气72 h IAP水平比较，差异均有统计学意义（P<0.05）；其中通气24 h及通气72 h C组IAP水平高于A组与B组（P<0.05）。不同时间点B组及C组IAP水平比较，差异均有统计学意义（P<0.05）；C组患儿通气24 h IAP水平高于入院时，通气72 h IAP水平高于入院时及通气24 h（P<0.05）。C组入院72 h IAP增高亚组PIP、FiO2、MODS发生率高于IAP正常亚组（P<0.05）。结论　不同给氧方式（鼻导管吸氧、经鼻CPAP及机械通气）所致气道压力不同对IAP可能会产生影响；在机械通气中PIP及FiO2两个参数对IAP影响明显，提示临床治疗中应尽早下调此两项参数，减少医源性损害。动态监测肺炎患儿IAP水平，对重症患儿病情演变及脏器损害程度有监测意义。

关键词: 重症肺炎, 儿童, 机械通气, 腹内压, 降钙素原, C反应蛋白