ObjectiveTo monitor the diaphragm function of mechanical ventilated patients in the intensive care unit. MethodsA prospective study was conducted on mechanical ventilation patients who had been evaluated by ventilation weaning screening test and planning to underwent spontaneous breathing trial between May 2013 and November 2013. A newly designed multi-function esophageal electrode was used to record the phrenic nerve conduction time (PNCT),diaphragm compound muscle action potential (CMAP) and twitch transdiaphragmatic pressure (TwPdi) elicited by bilateral anterolateral magnetic phrenic nerve stimulation. Results14 patients were recruited in this study. 1 case exited because of intolerance of repetitive magnetic stimulation,2 cases had no diaphragmatic electromyographic signals nor twitch signals,1 case had diaphragmatic electromyographic signal but could not be elicited by magnetic stimulation,1 case had no available TwPdi value with PNCT of 7.2 ms and CMAP of 1.26 mV. In the rest 9 cases,the PNCT,CMAP and TwPdi were (8.5±1.5)ms,(1.01±0.35)mV,(11.2±4.7)cm H2O,respectively. ConclusionNewly designed multi-function esophageal electrode catheter combined with bilateral anterolateral magnetic phrenic nerve stimulation can be used for non-volitional comprehensive assessment of diaphragm in critically ill patients,but not suitable for all subjects.
ObjectiveTwitch transdiaphragmatic pressure is used to evaluate the diaphragm function of mechanical ventilated chronic obstructive pulmonary disease patients before weaning in the intensive care unit, and compared with healthy normal values.MethodsPatients were recruited if they were with acute exacerbation of chronic obstructive pulmonary disease, admitted between May to November in 2013 and December 2014 to February 2016 to the intensive care unit in the First Affiliated Hospital of Guangzhou Medical University, intubated and mechanical ventilated more than 72 hours, and recovered to the clinical stability states after passing the readiness to wean, getting ready for spontaneous breathing test. The newly designed esophageal electrode catheter and bilateral anterolateral magnetic phrenic nerves stimulation were utilized to detect the twitch transdiaphragmatic pressure. At the same time, the function of diaphragm was detected in 10 healthy adults for comparison.ResultsTwenty-two patients were recruited in this study. Two cases had no twitch signals. In the rest 20 cases, the twitch transdiaphragmatic pressure was (7.6±2.5) cm H2O. In 10 healthy adults, twitch transdiaphragmatic pressure was (26.7±4.9) cm H2O. There was significant difference between the patients and the health control subjects (P<0.05).ConclusionTwitch transdiaphragmatic pressure is significantly decreased in weaning chronic obstructive pulmonary disease patients compared with healthy adults.