[The change in strategy of mechanical ventilation: a single center study in China].

OBJECTIVE: To observe the treatment strategy and its changes in mechanical ventilation (MV) in a single medical center. METHODS: Five hundred and two patients undergoing MV for at least 24 hours from January 1994 to December 1997 (control group) and from January 2004 to December 2006 (study group) in a total of 1 090 patients who were admitted to intensive care unit (ICU) Fuxing Hospital, Capital Medical University during the 2 periods were investigated. Datas including causes for the initiation of MV, ventilator modes and treatment parameters, weaning methods, and prognosis of patients were collected. RESULTS: The total incidence of MV was 46.1% (502/1 090). The incidence of MV in control group was 48.9% (184/376), and that in study group was 44.5% (318/714), respectively. The main causes for MV of 502 patients were pneumonia 18.3% (92 cases), acute exacerbation of chronic obstructive pulmonary disease (AECOPD) 16.3% (82 cases), postoperation 13.7% (69 cases), coma 14.1% (71 cases) , and acute respiratory distress syndrome (ARDS) 12.7% (64 cases). The initial ventilator mode: 59.8% (110/184) or 23.0%(73/318) in control or study group was assist/control ventilation (A/C), and 57.2% (182/318) or 20.7%(38/184) in study or control group was pressure support ventilation (PSV), and there was significant difference between the two groups (both P<0.01). The use of noninvasive ventilation (NPPV) in study group was obviously increased compared with control group [10.4% (33/318) vs. 3.8% (7/184), P<0.01]. The mean pressure level of pressure support (PS) of all patients was 14.0 cm H(2)O (1 cm H(2)O=0.098 kPa), the mean positive end-expiratory pressure (PEEP) of both groups was 5.0 cm H(2)O. Compared with control group, PEEP (cm H(2)O) level in patients with ARDS was significantly higher (8.0 vs. 6.0, P<0.01) and volume tidal (V(T), ml) was significantly lower (400 vs. 550, P<0.01) in study group. The most frequently used weaning methods of both groups were T-piece, T-piece+PSV and PSV. The use of T-piece in study group was significantly higher than that in control group [84.4% (184/218) vs. 35.1% (40/114), P<0.01], and PSV was lower than that in control group [2.8% (6/218) vs. 29.8% (34/114), P<0.01]. The total mortality of MV patients in two groups in ICU was 49.6%(249/502). There was no significant difference of the mortality between study group and control group (54.6% vs. 55.4%, P=0.887). CONCLUSION: The ventilator modes and settings had been changed in a single medical center in the past 10 years. It is speculated that the changes are related with the results observed in some multicenter randomized controlled trials (RCTs).