Comparison of three lung recruitment maneuvers in the treatment of severe extra-pulmonary acute respiratory distress syndrome / 中国综合临床

Objective To investigate the efficacy and side effects of three recruitment maneuvers (RM) for severe extra-pulmonary acute respiratory distress syndrome ( ARDS). Methods A total of sixty-three extra-pulmonary ARDS patients were enrolled and randomly divided into three groups, which were treated with sustained inflation (SI),increment of positive end-expiratory pressure (IP) and pressure control ventilation (PCV) respectively. The oxygenation index ( PaO2/FiO2) before and after lung recruitment was recorded in patients with complete lung recruitment,and the cause of discontinuation of lung recruitment was recorded in patients with incomplete lung recruitment. Positive end-expiratory pressure (PEEP) was recorded in patients who completed lung recruitment with the latter two methods when they reached the maximum degree of lung recruitment. The mortality rate of 14 d in 3 groups was recorded, and the clinical characteristics and prognosis differences were compared before and after each group. Results With PaO2/FiO2as the standard, all the three methods of pulmonary reexpansion could make the lungs obviously reexpanse. The PaO2/FiO2of each group before, 5 minutes after and 1 hour after reexpansion were respectively as below (SI group: 70. 4±14. 8 mmHg,306. 8±97. 5 mmHg,229. 6±116. 2 mmHg; IP group:74. 9±13. 6 mmHg,328. 0 ± 95. 5 mmHg,252. 8 ± 111. 0 mmHg; PCV group: 67. 8 ± 14. 9 mmHg, 304. 2 ±82. 2 mmHg,223. 7±83. 6 mmHg. P＜0. 01). There were no significant differences among the three methods in the effect of RM (P＞0. 05). PEEP of IP group is higher than that of PCV group at the time of maximum RM (20. 3±2. 5 cmH2O vs. 18. 5±1. 8 cmH2O,P＜0. 05). There were significant differences in the incidence of adverse reactions caused by the three methods (54. 5%(12/22) in SI group,35. 0%(7/20) in IP group and 9. 6%(2/21) in PCV group. The 14 d mortality of each group was 63. 6%(14/22) in SI group,70. 0%(14/20) in IP group and 61. 9%(13/21) in PCV group,with no significant difference (P＞0. 05) . Conclusion The effects of three methods of lung recruitment on severe pulmonary exogenous ARDS patients were similar, but there was no significant difference in prognosis. Adverse reactions of SI method leads to the greatest probability of discontinuation of lung recruitment,and that of the PCV method is the smallest. Under the same effect of lung recruitment, IP method needs higher PEEP than PCV method. In practice,PCV method should be preferred.

Comparative study of three recruitment maneuvers in acute respiratory distress syndrome caused by extrapulmonary disease / 中国医师进修杂志

Objective To evaluate the effects and side effects of three different recruitment maneuvers (RM) in acute respiratory distress syndrome (ARDS) caused by extrapulmonary disease.Methods Forty-four patients of extrapulmonary ARDS, according to crossover design methods, were undergone three RM in different periods, including sustained inflation (SI), increase progressively positive end expiratory pressure (IP), pressure control ventilation (PCV). Heart rate (HR), mean arterial blood pressure (MAP), central venous pressure (CVP), oxygenation index, lung compliance were recorded before and after RM, and were analyzed for statistical analysis. Results Oxygenation index and lung compliance were increased obviously in a short time after RM, improvement of IP method were better more obviously than the other two methods [1 h oxygenation index after RM:227 ± 42 vs 190 ± 19,186 ± 21; lung compliance:(59.4±12.5 ) ml/cm H2O(1 cm H2O = 0.098 kPa) vs (50.1 ± 9.3 ), (49.7 ± 10.6) ml/cm H2O;P＜ 0.05], 2h after RM,there were no statistical difference among the three methods (P＞0.05). After RM,HR and CVPwere increased, MAP was decreased in a short time, changes of SI method were smaller than the other two inethods [10 min HR after RM: (94.0±10.3 ) beats/min vs (116.0 ± 14.8 ), ( 107.0 ± 5.7 ) beats/min; CVP:(13.7±3.1 )cm H2O vs ( 18.4 ± 6.7 ), ( 15.4 ± 2.7 )cm H2O; MAP: ( 87.0 ± 12.1 ) mm Hg( 1 mm Hg = 0.133 kPa) vs (73.0 ± 4.8), (81.0 ± 6.6) mm Hg;P＜ 0.05), 20 min after RM, there were no statistical difference among the three methods (P＞ 0.05). Conclusion When extrapulmonary ARDS undergo RM ,IP method is the most effective on increasing oxygenation index and lung compliance, SI method has the smallest side effect on hemodynamics.

Comparison of volume-control and pressure-control ventilation during one-lung ventilation / 대한마취과학회지

BACKGROUND: We hypothesized that pressure control ventilation allows a more even distribution in the lung and better maintenance of the mean airway pressure than is achieved with volume control ventilation. We try to compare the effect of pressure control ventilation (PC) with that of volume control ventilation without an end-inspiratory pause (VC) during one-lung ventilation (OLV) in an anesthetized, paralyzed patient for performing thoracopic bullectomy of the lung. METHODS: We ventilated 20 patients with VC and PC after the insertion of a thoracoscope in continual order for, at least for 15 minutes, for each, VC and PC procedure. At the end of VC and PC, the respiratory mechanics, gasometrics, and hemodynamic parameters were measured and collected. RESULTS: We found no significant differences between VC and PC except for the peak inspiratory airway pressure (PIP), the mean airway pressure and the arterial oxygen partial pressure (PaO2). The PIP was significantly decreased from 27.0 +/- 6.0 cmH2O (VC) to 21.8 +/- 5.4 cmH2O (PC). The mean airway pressure was significantly increased from 8.6 +/- 1.6 cmH2O (VC) to 9.4 +/- 2.0 cmH2O (PC), and the PaO2 was significantly increased from 252.9 +/- 97.3 mmHg (VC) to 285.2 +/- 103.8 mmHg (PC). CONCLUSIONS: If PC allows mechanical ventilation with the same tidal volume and respiratory rate as VC during OLV, then PC significantly increases the PaO2 but this is not clinically significant, and the PC significantly decreases the PIP, which induces barotrauma or volutrauma when the PIP is excessively high.

Effect of pressure rise time on tidal volume and gas exchange during pressure control ventilation / 결핵

BACKGROUND: Pressure rise time (PRT) is the time in which the ventilator aclieves the set airway pressure in pressure-targeted modes, such as pressure control ventilation (PCV). With varying PRT, in principle, the peak inspiratory flow rate of the ventilator also varies. And if PRT is set to a shorter duration, the effective duration of target pressure level would be prolonged. which in turn would increase inspiratory tidal volume(Vti) and mean airway pressure(Pmean). We also postulated that the increase in Vti with shortening of PRT may relate inversely to the patients' basal airway resistance. METHODS: In 13paralyzed patients on PCV(pressure control 18±9.5cm H2, FIO2 0.6±0.3, PEEP 5±3cm H2O, f20/min, I : E, 1 : 2) with Servo 300(Siemens-Elema, Solna, Sweden)from various causes of respiratory failure, PRT of 10%, 5% and 0% were randomly applied. At 30min of each PRT trial, peak inspiratory flow (PIF, L/sec), Vti(ml), Pmean(cm H2O) and ABGA were determined. RESULTS: At PRT 10, 5% and 0%, PIF were 01.69±0.13, 0.77±0.19, 0.83±0.22, respectively(p<0.001). Vti were 425±94, 439±101, 456±106, respectively(p<0.001), and Pmean were 11.2±3.7, 12.0±3.7, 12.5±3.8, respectively(p<0.001). pH were 7.40±0.08, 7.40 ±0.92, 7.41±0.96, respectively (p=0.004) ; PaCO2 (mm Hg) were 47.4±15.8, 47.2±15.7, 44.6±16.2, respectively (p=0.004) ; PAO2 - PaO2 (mm Hg) were 220±98, 224±95, 227±94, respectively(p=0.004) ; and Vd/Vt as determined by (PaCO2 - P CO2/PaCO2 were 0.67±0.07, 0.67±0.08, 0.66 ±0.08, respectively(p=0.007). The correlation between airway resistance and change of Vti from PRT 10% to 0% were r=-0.243(0.498). CONCLUSION: Shortening of pressure rise time during PCV was associated with associated with increased tidal volume, increased mean airway pressure and lower PaCO2.