重症监护病房机械通气患者正压拔管与负压拔管的比较研究

Comparison of positive and negative pressure extubation after mechanical ventilation in intensive care unit patients

目的:探讨正压拔管和负压拔管对重症监护病房(ICU)行机械通气患者的影响。方法:采用前瞻性随机对照研究方法,选择2019年1月至2021年3月南通大学附属南京江北医院ICU收治的行机械通气后成功通过自主呼吸试验(SBT)的105例患者作为研究对象,按随机数字表法分为正压拔管组(53例)和负压拔管组(52例)。拔管时所有患者均取半卧位(抬高床头30°~45°),清除口、鼻、咽喉及气管内分泌物。负压拔管组断开呼吸机,将吸痰管插入气管导管并越过远端开口,行气管内持续负压吸引,同时抽空气管导管气囊后,将吸痰管随同气管导管一起拔出;正压拔管组不断开呼吸机,在原有SBT模式下,指导患者用力吸气,当患者达到吸气高峰时,抽空气囊后拔除气管导管;拔管后两组均给予鼻导管吸氧(氧流量5 L/min)。记录两组患者拔管后5 min及1 h动脉血气分析指标〔pH值、动脉血氧分压(PaO_(2))和动脉血二氧化碳分压(PaCO_(2))〕,观察两组患者拔管后30 min内的生命体征(包括呼吸急促、心动过速、血压升高、血氧饱和度下降)以及并发症发生情况(包括严重呛咳、气道高反应、肺炎)。结果:拔管后5 min,正压拔管组患者PaO_(2)明显高于负压拔管组〔mmHg(1 mmHg≈0.133 kPa):123.4±30.2比111.0±21.1,P<0.05〕,pH值和PaCO_(2)略低于负压拔管组〔pH值:7.411±0.042比7.419±0.040,PaCO_(2)(mmHg):39.7±4.7比40.5±5.6〕,但差异均无统计学意义(均P>0.05);拔管后1 h,正压拔管组患者pH值、PaO_(2)、PaCO_(2)均略低于负压拔管组,但差异均无统计学意义。拔管后30 min内,正压拔管组呼吸急促、心动过速、血压升高及血氧饱和度下降发生率均明显低于负压拔管组〔呼吸急促:9.4%(5/53)比28.8%(15/52),心动过速:15.1%(8/53)比32.7%(17/52),血压升高:11.3%(6/53)比30.8%(16/52),血氧饱和度下降:7.5%(4/53)比34.6%(18/52),均P<0.05〕,严重呛咳发生率亦明显低于负压拔管组〔9.4%(5/53)比30.8%(16/52),P<0.05〕,但两组间气道高反应发生率比较差异无统计学意义〔1.9%(1/53)比5.8%(3/52),P>0.05〕。两组患者均未在拔管后48 h内发生肺炎。结论:正压拔管能保证ICU行机械通气患者得到充分氧合,避免低氧,还能降低严重呛咳发生率,有利于生命体征的稳定。

Objective To investigate the effect of positive and negative pressure extubation on mechanical ventilation patients in the intensive care unit(ICU).Methods A prospective randomized controlled study was performed,105 ICU patients who successfully passed the spontaneous breathing test(SBT)after mechanical ventilation of Nanjing Jiangbei Hospital Affiliated to Nantong University from January 2019 to March 2021 were enrolled.According to random number table method,they were randomly divided into positive pressure extubation group(53 cases)and negative pressure extubation group(52 cases).During extubation,all patients were placed in semi-decubitus position(raising the head of bed at an angle range from 30°-45°),the secretions from mouth,nose,throat and trachea were removed.In the negative pressure extubation group,the sputum suction tube was inserted into the tracheal tube and passed over the distal opening to carry out continuous negative pressure suction in the tracheal tube after disconnecting the ventilator.Meanwhile,after the tracheal tube balloon was evacuated,the sputum suction tube was pulled out together with the tracheal tube.In the positive pressure extubation group,the patients were guided to inspiratory forcibly under the original SBT mode.When the patients reached the inspiratory peak,the ballon was evacuated and the tracheal tube was removed.After extubation,all patients were given nasal catheter oxygen inhalation(oxygen flow 5 L/min).Arterial blood gas analysis indexes[pH value,arterial partial pressure of oxygen(PaO_(2))and arterial partial pressure of carbon dioxide(PaCO_(2))]were recorded 5 minutes and 1 hour after extubation in both groups.Vital signs(including tachypnea,tachycardia,elevated blood pressure and decreased oxygen saturation)and complications(including severe cough,airway hyperresponsiveness and pneumonia)were observed 30 minutes after extubation in both groups.Results Five minutes after extubation,blood gas analysis showed that the PaO_(2) of positive pressure extubation group was significantly higher than that of negative pressure extubation group[mmHg(1 mmHg≈0.133 kPa):123.4±30.2 vs.111.0±21.1,P<0.05],the pH value and PaCO_(2) in positive pressure extubation group were slightly lower than that of negative pressure extubation group[pH value:7.411±0.042 vs.7.419±0.040,PaCO_(2)(mmHg):39.7±4.7 vs.40.5±5.6],but the differences were not statistically significant(both P>0.05).One hour after extubation,the pH value,PaO_(2) and PaCO_(2) in positive pressure extubation group were slightly lower than those in negative pressure extubation group,but the differences were not statistically significant.Within 30 minutes after extubation,the incedences of tachypnea,tachycardia,elevated blood pressure and oxygen desaturationin in positive pressure extubation group were significantly lower than those in negative pressure extubation group[tachypnea:9.4%(5/53)vs.28.8%(15/52),tachycardia:15.1%(8/53)vs.32.7%(17/52),elevated blood pressure:11.3%(6/53)vs.30.8%(16/52),oxygen desaturation:7.5%(4/53)vs.34.6%(18/52),all P<0.05],the incidence of severe cough in positive pressure extubation group was significantly lower than that in negative pressure extubation group[9.4%(5/53)vs.30.8%(16/52),P<0.05],but there was no significant difference in the incidence of complications of airway hyperresponsiveness between the two groups[1.9%(1/53)vs.5.8%(3/52),P>0.05].No pneumonia occurred in both groups within 48 hours after extubation.Conclusion The positive pressure extubation method can ensure full oxygenation of patients undergoing mechanical ventilation in ICU,avoid hypoxia,and reduce the occurrence of hypoxia and severe cough,which is more conducive to the stability of vital signs.