Efficacy And Safety Of ECMO To Rescue Dyspnea Patients With Intra-abdominal Hypertension Refractory To Mechanical Ventilation

Research background and purpose: Patients with intra-abdominal hypertension(IAH)/ abdominal compartment syndrome(ACS)often present with dyspnea,which is primarily due to IAH induced respiratory failure.In severe cases,respiratory and circulatory failure can develop,and mechanical ventilation is the conventional approach to improve dyspnea in such patients.Patients who fail to respond to mechanical ventilation have a very poor prognosis and high mortality.Extracorporeal Membrane Oxygenation(ECMO)is the most advanced means of cardiopulmonary support today,which enables the blood returne to the body through an oxygenation system composed of pump,membrane oxygenator and heat exchanger,then the body obtains oxygenated blood and circulatory power.ECMO has also been reported for the treatment of IAH induced dyspnea,but its efficacy and safety remain uncertain.This study aimed to investigate whether ECMO could effectively improve the outcomes of patients with dyspnea complicated by IAH who failed to respond to mechanical ventilation treatment by searching the literature.Subjects and methods: In this study,we searched CNKI,VIP,Wanfang,Pubmed,Cochrane Library,Ovid,Web of Science and Embase databases for the published articles on dyspnea(respiratory failure,with or without circulatory failure)induced by IAH patients who had received ECMO therapy.The publication time was from the establishment of the database to may 2021,with language restricted to Chinese and English.Primary outcome measures were survival and ECMO related complications.Other relevant indicators included:age,gender,year of publication,country or region,primary etiology,reasons for ECMO initiation,ECMO catheterization mode,mode of ECMO drainage,length of ECMO treatment,protocol for perioperative management of ECMO,solution of abdominal pressure and changes before and after the ECMO run.Inclusion criteria: concurrently meet the following five points:(1)Patient: patients diagnosed with IAH,accompanied by dyspnea or respiratory failure,whose dyspnea or respiratory failure could not be improved by mechanical ventilation;(2)IAH diagnosis referred to WSACS guidelines,IAP ≥ 12 mm Hg,or had other relevant author opinions or objective and reliable medical records;(3)Dyspnea or respiratory failure was defined as the description of exact symptoms or disease status,or arterial blood gas analysis suggested arterial pressure of oxygen <60mmhg;(4)Interventions: ECMO therapy;(5)Primary outcome measures were included: specific survival and ECMO related complications.Exclusion criteria:(1)Excluded duplicate published literatures;(2)Review,bibliography,etc;(3)Nonclinical research literatures;(4)Full texts were not available,or detailed data could not be extracted(e.g.graphs,etc.).Results: a total of 15 literatures that met the inclusion criteria were collected,all of which were case reports or descriptive studies.A total of 20 patients were included,and 15 patients survived with a survival rate of 75%.The age distribution of such patients treated with ECMO ranged from 2 days to 69 years old,with an average of 30.9±20.9,9 in the minor group(age < 18 years)had a survival rate of 77.8%,and 11 in the adult group(age ≥ 18 years)had a survival rate of 72.7%,with no significant difference between the survival rates(P > 0.05).There was little difference in the number of males and females,with6 males,66.7% survived,and 9 females,88.9% survived,and there was no significant difference in survival rates between the two groups(P > 0.05).The included literature was first published in 2007,the latest reported in 2021,there was a trend of increasing relevant reports in recent years,but no cohort study was found.The countries or regions where the literature from were mainly United States,China.6 patients(40%)had VA-ECMO with 83.3% survived,including 2 patients with superior vena cava drainage and 1 patient with both superior and inferior vena cava drainage,9 patients(60%)had VV-ECMO with77.8% survived,including 1 patient with superior vena cava drainage and 2patients with inferior vena cava drainage,with no significant difference between the two groups(P > 0.05).The shortest duration of ECMO is 0.25 days,while the longest is 12 days,with an average of 6.6±3.5 days.Decompression laparotomy was performed in 14 patients(70%),with a survival rate of 64.3%,and non-decompression laparotomy was performed in 6 patients(30%),with a survival rate of 100%,no significant difference between the two groups(P >0.05).Conclusion: Based on the results of existing observational studies,ECMO may be useful in improving outcome and survival in partially patients with dyspnea induced by IAH and refractory to mechanical ventilation.However,some key problems remain unclear,like when ECMO should be used and whether VV-ECMO or VA-ECMO should be used,whether superior vena cava drainage is superior to inferior vena cava drainage,and whether decompression laparotomy during ECMO increases the risk of bleeding.Limited by the number and quality of included studies,the efficacy and safety of ECMO to rescue dyspnea patients with IAH refractory to mechanical ventilation also need to be confirmed by future well-designed prospective and controlled studies.