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.
Objective To investigate the effect of prone position ventilation (PPV) on hemodynamics in patients with interstitial lung disease (ILD) concurrent with acute respiratory distress syndrome (ARDS) or not. Methods Severe ARDS patients received PPV treatment in intensive care unit from 2013 to 2015 were retrospectively analyzed. Pulse index continuous cardiac output (PiCCO) monitoring indices were compared 2h before PPV (PPV-2), in-PPV (PPVmean) and 2h after turn back to supine position (PPV+2), including mean arterial pressure (MAP), cardiac index (CI), intrathoracic blood volume index (ITBVI), etc. Heart function, liver function, renal function, coagulative function were compared before and after all the PPV treatment. Results Thirty-six severe pulmonary ARDS patients were recruited. Norepinephrine (NE) dose was (0.14±0.10) μg·kg-1·min-1 and lactate concentration was (1.70±0.57) mmol/L before PPV. CI in all the patients was increased [(4.06±0.95) L·min-1·m-2 vs. (3.98±1.05) L·min-1·m-2, P > 0.05) and central venous oxygen saturation, ITBVI [(76.94±8.94)% vs. (70.67±8.23)%, (982.17±245.87) mL/m2 vs. (912.97±177.65) mL/m2, P < 0.05)] were significantly increased compared with PPV-2, while heart rate (HR), MAP, urine volume were decreased (P > 0.05). The patients were divided into an ILD group (n=17) andanon-ILD group (n=19),and no significant differences were found in baseline data between two groups. Compared with PPV-2, MAP was significant decreased at PPV+2 [(85.44±10.84) mm Hg vs. (89.21±10.92) mm Hg, P < 0.05) in the ILD group. Compared with PPVmean, CI was obviously declined at PPV+2 in the ILD group. Activated partial thromboplastin time was increased [(67.04±97.52)s vs. (41.24±8.72) s, P < 0.05] and BUN was higher [(10.64±4.95) μmol/L vs. (8.18±3.88) μmol/L, P < 0.05] in the ILD group, while no significant difference was found in the non-ILD group. Conclusion PPV will not affect cardiac output in severe ARDS patients with ILD. It can increase venous return and improve tissue perfusion, but the perfusion of the abdomen organ need to be monitored cautiously.