肺复张干预对急性呼吸窘迫综合征犬吸痰后血流动力学的影响

目的 探讨不同肺复张干预对急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)犬吸痰后血流动力学的影响.方法 8只健康杂种犬,平均体质量为(23.69±7.35)kg,经静脉注射油酸制备ARDS模型.ARDS犬气管内开放式吸痰后按随机顺序实施以下6种肺复张干预:(1)吸...     

Closed suctioning system: Critical analysis for its use

Aim:  To determine the efficacy and effectiveness of the closed suctioning system.
Method:  Literature review articles were accessed from the following databases: PubMed, EMBASE, CINAHL, and Cochrane Library. The literature review criteria included: all publication styles except meta-analysis, participants that were ≥18 years, written in English, and published between 1973 and 2008.
Results:  This literature review revealed that the efficacy and effectiveness of the closed suctioning system remains to be demonstrated. The device manufacturers' studies focused on cost reduction, cross-contamination, and preservation of the oxygen saturation of patients during endotracheal suctioning; however, the clinical studies focused on the use of closed suctioning systems to prevent ventilator-associated pneumonia. The reviewed studies had small sample sizes with heterogeneous demographics and non-randomized controls. Recent studies suggest that closed suctioning systems are no better than open suctioning systems in terms of mortality, morbidity, or the cost-benefit ratio. A few studies did indicate that the closed suctioning system might reduce the loss of lung volume and oxygen desaturation.
Conclusion:  The studies reviewed in this article suggest that the evidence on the efficacy and effectiveness of closed suctioning systems is inconclusive. Only limited populations will benefit clinically from the use of this device. There is a need for further studies with randomized controlled trials to explore the use of closed suction systems and to update current clinical practise guidelines.     

机械通气患者吸痰前气管内滴注生理盐水湿化的比较研究

目的探讨对已经进行湿化气道的机械通气患者吸痰时,滴注生理盐水与否对吸痰效果以及机械通气相关并发症的影响.方法选择建立人工气道机械通气30 h以上患者101例,随机分成A组50例和B组51例,A组吸痰时不滴注生理盐水,B组吸痰时按传统方法常规滴注生理盐水2ml,通过观察吸痰时患者咳嗽反应、血氧饱和度、心率、血压的变化以及痰液黏稠度、呼吸机相关性肺炎(VAP)的发生率等指标进行研究.结果两组吸痰时患者心率、收缩压以及痰液黏稠度之间差异无统计学意义,B组滴入生理盐水后吸痰前心率、血压均升高,而血氧饱和度下降,与B组比较,A组吸痰时呛咳、VAP的发生率明显下降.结论吸痰时滴注生理盐水进行湿化会导致血氧饱和度下降、舒张压升高、患者刺激性咳嗽、VAP的发生率升高等不利影响,因此,机械通气吸痰不应将滴注生理盐水作为常规操作.     

Commentary: Morrow B, Futter M, Argent A. (2006). Effect of endotracheal suction on lung dynamics in mechanically-ventilated paediatric patients

Endotracheal suctioning is performed regularly in ventilated infants and children to remove obstructive secretions. The effect of suctioning on respiratory mechanics is not known. This study aimed to determine the immediate effect of endotracheal suctioning on dynamic lung compliance, tidal volume and airway resistance in mechanically ventilated paediatric patients by means of a prospective observational clinical study. Lung mechanics were recorded for 5 min before and 5 min after a standardized suctioning procedure in 78 patients intubated with endotracheal tubes of ≤4·0 mm internal diameter. Twenty‐four patients with endotracheal tube leaks ≥20% were excluded from analysis. There was a significant overall decrease in dynamic compliance (p < 0·001) and mechanical expired tidal volume (p = 0·03) following suctioning with no change in the percentage of endotracheal tube leak (p = 0·41). The change in dynamic compliance was directly related to both endotracheal tube and catheter sizes. There was no significant change in expiratory or inspiratory airway resistance following suctioning (p > 0·05). Although most of the patients (68·5%) experienced a drop in dynamic compliance following suctioning, dynamic compliance increased in 31·5% of patients after the procedure. This study demonstrates that endotracheal suctioning frequently causes an immediate drop in dynamic compliance and expired tidal volume in ventilated children with variable lung pathology, intubated with small endotracheal tubes, probably indicating loss of lung volume caused by the suctioning procedure. There is no evidence that suctioning reduces airway resistance. Abstract reprinted from the Australian Journal of Physiotherapy volume 52, Morrow B et al., ‘Effect of endotracheal suction on lung dynamics in mechanically‐ventilated paediatric patients’, pages 121–126. © 2006, reproduced with permission from the Australian Physiotherapy Association.     

不同吸痰方式对急性呼吸窘迫综合征血流动力学影响的实验研究

目的研究更适宜急性呼吸窘迫综合征(ARDS)机械通气气管内吸痰的方式。方法采用静脉注射油酸制备动物ARDS模型;每只犬随机选择使用开放式气管内吸痰(OS)和密闭式气管内吸痰(CS)2种吸痰方式。于吸痰前后记录血流动力学等监测指标的数据。结果OS和CS后,犬平均肺动脉压(MPAP)与吸痰前比较均明显升高(P<0.05);OS后平均动脉压(MAP)显著升高(P<0.05)。结论OS、CS均可影响血流动力学的稳定。本研究提示,在护理工作中,对ARDS机械通气者应重视吸痰引起的继发性损害,加强吸痰前后血流动力学等监测。     

Endotracheal suctioning versus minimally invasive airway suctioning in intubated patients: a prospective randomised controlled trial

STUDY OBJECTIVE: Endotracheal suctioning in intubated patients is routinely applied in most ICUs but may have negative side effects. We hypothesised that on-demand minimally invasive suctioning would have fewer side effects than routine deep endotracheal suctioning, and would be comparable in duration of intubation, length of stay in the ICU, and ICU mortality. DESIGN: Randomised prospective clinical trial. SETTING: In two ICUs at University Hospital Groningen, the Netherlands. PATIENTS: Three hundred and eighty-three patients requiring endotracheal intubation for more than 24 h. INTERVENTIONS: Routine endotracheal suctioning (n=197) using a 49-cm suction catheter was compared with on-demand minimally invasive airway suctioning (n=186) using a suction catheter only 29 cm long. MEASUREMENTS AND RESULTS: No differences were found between the routine endotracheal suctioning group and the minimally invasive airway suctioning group in duration of intubation [median (range) 4 (1-75) versus 5 (1-101) days], ICU-stay [median (range) 8 (1-133) versus 7 (1-221) days], ICU mortality (15% versus 17%), and incidence of pulmonary infections (14% versus 13%). Suction-related adverse events occurred more frequently with RES interventions than with MIAS interventions; decreased saturation: 2.7% versus 2.0% (P=0.010); increased systolic blood pressure 24.5% versus 16.8% (P<0.001); increased pulse pressure rate 1.4% versus 0.9% (P=0.007); blood in mucus 3.3% versus 0.9% (P<0.001). CONCLUSIONS: This study demonstrated that minimally invasive airway suctioning in intubated ICU-patients had fewer side effects than routine deep endotracheal suctioning, without being inferior in terms of duration on intubation, length of stay, and mortality.     

Endotracheal suctioning in hypoxemic patients

Hypoxemic patients are at high risk of developing endotracheal suctioning (ES)-related complications, particularly deterioration of oxygenation and lung derecruitment, which have the potential to worsen lung injury. To prevent or limit these complications, open suctioning should be avoided and closed systems should be preferentially used. To improve cost-effectiveness, the closed system should not be changed routinely but only in case of mechanical failure or visible soiling. Suctioning should be performed only when clinically indicated, avoiding unnecessary procedures. Particular attention should be paid to technical aspects of the procedure, such as suction catheter size, the level of negative pressure, the depth of suction catheter insertion, and the duration of suctioning, which have a huge impact on ESrelated complications. Hyperoxygenation and recruiting maneuvers, particularly when performed during suctioning, can be useful in the most severely hypoxemic patients, while hyperinflation before suctioning must be avoided.     

两种气道内深部吸痰方法的效果观察及护理

目的探讨两种气道内深部吸痰方法的效果。方法将40例清理呼吸道无效、抗拒吸痰的患者,根据吸痰方法分为观察组21例,对照组19例。两组均用口咽通气管建立临时气道,对照组用普通枕头垫高肩部(≤10cm)后行气道内深部吸痰;观察组用吸痰枕垫高肩部15cm后行气道内深部吸痰。观察记录两组患者吸痰效果(吸痰次数、吸痰量)和气道黏膜损伤情况。结果观察组气道黏膜损伤发生率低于对照组;每日吸痰次数较对照组少;每次吸痰量较对照组多,两组比较,均P0.05,差异具有统计学意义。结论采用肩部抬高15cm,暂时留置吸痰管等方法行气道内深部吸痰,可提高吸痰效果和降低气道黏膜损伤的发生。     

Endotracheal suctioning with or without instillation of isotonic sodium chloride solution in critically ill children.

BACKGROUND: Instillation of isotonic sodium chloride solution for endotracheal tube suctioning is controversial. Research has focused on the effect of such instillation in adults; no studies in children have been published. OBJECTIVES: (1) To describe differences in oxygen saturation depending on whether or not isotonic sodium chloride solution is instilled during suctioning and (2) to describe the rates of occlusion of endotracheal tubes and nosocomial pneumonia. METHODS: A convenience sample of 24 critically ill patients were enrolled before having suctioning and after informed consent had been given. Ages ranged from 10 weeks to 14 years. Patients were randomized to 1 of 2 groups. In group 1, subjects received between 0.5 and 2.0 mL of isotonic sodium chloride solution, depending on their age, once per suctioning episode. In group 2, subjects received no such solution. A total of 104 suctioning episodes were analyzed. Oxygen saturation was recorded at predetermined intervals before and for 10 minutes after suctioning. Occlusion of endotracheal tubes and rates of nosocomial pneumonia also were compared. RESULTS: Patients who had isotonic sodium chloride solution instilled experienced significantly greater oxygen desaturation 1 and 2 minutes after suctioning than did patients who did not. No occlusions of endotracheal tubes and no cases of nosocomial pneumonia occurred in either group. CONCLUSIONS: Results of this study support a growing body of evidence that instillation of isotonic sodium chloride solution during endotracheal tube suctioning may not be beneficial and actually may be harmful.     

气管内吸痰术的研究与应用进展

本文通过查阅相关文献,从吸痰时机、时间,吸痰管的选择,吸痰的负压,吸痰方式,吸痰方法及密闭式吸痰等方面对气管内吸痰术的研究共识与应用进展进行综述,以促进吸痰护理操作日臻完善。     

Bacterial growth in secretions and on suctioning equipment of orally intubated patients: a pilot study.

BACKGROUND: Contamination of equipment, colonization of the oropharynx, and microaspiration of secretions are causative factors for ventilator-associated pneumonia. Suctioning and airway management practices may influence the development of ventilator-associated pneumonia. OBJECTIVES: To identify pathogens associated with ventilator-associated pneumonia in oral and endotracheal aspirates and to evaluate bacterial growth on oral and endotracheal suctioning equipment. METHODS: Specimens were collected from 20 subjects who were orally intubated for at least 24 hours and required mechanical ventilation. At baseline, oral and sputum specimens were obtained for culturing, and suctioning equipment was changed. Specimens from the mouth, sputum, and equipment for culturing were obtained at 24 hours (n=18) and 48 hours (n=10). RESULTS: After 24 hours, all subjects had potential pathogens in the mouth, and 67% had sputum cultures positive for pathogens. Suctioning devices were colonized with many of the same pathogens that were present in the mouth. Nearly all (94%) of tonsil suction devices were colonized within 24 hours. Most potential pathogens were gram-positive bacteria. Gram-negative bacteria and antibiotic-resistant organisms were also present in several samples. CANCLUSIONS: The presence of pathogens in oral and sputum specimens in most patients supports the notion that microaspiration of secretions occurs. Colonization is a risk factor for ventilator-associated pneumonia. The equipment used for oral and endotracheal suctioning becomes colonized with potential pathogens within 24 hours. It is not known if reusable oral suction equipment contributes to colonization; however, because many bacteria are exogenous to patients' normal flora, equipment may be a source of cross-contamination.     

Closed system endotracheal suctioning maintains lung volume during volume-controlled mechanical ventilation

OBJECTIVE: A closed suction system (CS) maintains connection with the mechanical ventilator during tracheal suctioning and is claimed to limit loss in lung volume and oxygenation. We compared changes in lung volume, oxygenation, airway pressure and hemodynamics during endotracheal suctioning performed with CS and with an open suction system (OS). DESIGN: Prospective, randomized study. SETTING: Intensive care unit in a university hospital. PATIENTS: We enrolled ten patients, volume-controlled (VC) ventilated with a Siemens Servo 900 ventilator (PaO2/FIO2 192 +/- 70, PEEP 10.7 +/- 3.9 cmH2O). INTERVENTIONS: We performed four consecutive tracheal suction maneuvers, two with CS and two with OS, at 20-min intervals. During the suction maneuvers continuous suction was applied for 20 s. MEASUREMENTS AND MAIN RESULTS: We measured end-expiratory lung volume changes (delta VL), tidal volume (VTrt), respiratory rate (RR) and minute volume (VErt) by respiratory inductive plethysmography; arterial oxygen saturation (SpO2), airway pressure and arterial pressure (PA). Loss in lung volume during OS (delta VL 1.2 +/- 0.7 l) was significantly higher than during CS (delta VL 0.14 +/- 0.1 l). During OS we observed a marked drop in SpO2, while during CS the change was only minor. During CS ventilation was not interrupted and we observed an immediate increase in RR (due to the activation of the ventilator's trigger), while VTrt decreased, VErt was maintained. CONCLUSIONS: Avoiding suction-related lung volume loss can be helpful in patients with an increased tendency to alveolar collapse; CS allows suctioning while avoiding dramatic drops in lung volumes and seems to be safe during the VC ventilation setting that we used.     

Ventilator versus manual resuscitation bag as the method for delivering hyperoxygenation before endotracheal suctioning

A critical review and analysis of the current research on the efficacy of the ventilator versus the manual resuscitation bag (MRB) as the method of delivering hyperoxygenation/hyperinflation breaths before, during, and/or after endotracheal suctioning (ETS) is presented. Current research findings indicate that hyperoxygenation/hyperinflation breaths at 100% oxygen (O2) delivered via the ventilator have resulted in elevated blood-O2 levels which are either superior or equivalent to the MRB in preventing suction-induced hypoxemia. Delivery of hyperoxygenation/hyperinflation breaths using the MRB results in increased airway pressure, and increased hemodynamic consequences. Guidelines of clinical practice, based on current research findings, are presented. Areas for further research are identified.     

Effect of endotracheal suction on lung dynamics in mechanically-ventilated paediatric patients

Endotracheal suctioning is performed regularly in ventilated infants and children to remove obstructive secretions. The effect of suctioning on respiratory mechanics is not known. This study aimed to determine the immediate effect of endotracheal suctioning on dynamic lung compliance, tidal volume, and airway resistance in mechanically-ventilated paediatric patients by means of a prospective observational clinical study. Lung mechanics were recorded for five minutes before and five minutes after a standardised suctioning procedure in 78 patients intubated with endotracheal tubes < or = 4.0 mm internal diameter. Twenty-four patients with endotracheal tube leaks > or = 20% were excluded from analysis. There was a significant overall decrease in dynamic compliance (p < 0.001) and mechanical expired tidal volume (p = 0.03) following suctioning with no change in the percentage endotracheal tube leak (p = 0.41). The change in dynamic compliance was directly related to both endotracheal tube and catheter sizes. There was no significant change in expiratory or inspiratory airway resistance following suctioning (p > 0.05). Although the majority of patients (68.5%) experienced a drop in dynamic compliance following suctioning, dynamic compliance increased in 31.5% of patients after the procedure. This study demonstrates that endotracheal suctioning frequently causes an immediate drop in dynamic compliance and expired tidal volume in ventilated children with variable lung pathology, intubated with small endotracheal tubes, probably indicating loss of lung volume caused by the suctioning procedure. There is no evidence that suctioning reduces airway resistance.     

Patient recollection of airway suctioning in the ICU: routine versus a minimally invasive procedure

OBJECTIVE: Many patients have an unpleasant recollection of routine endotracheal suctioning after discharge from the Intensive Care Unit (ICU). We hypothesized that through minimally invasive airway suctioning discomfort and stress may be prevented, resulting in less recollection. DESIGN: A prospective randomized clinical trial. SETTING: Two ICUs at the University Hospital of Groningen, the Netherlands. PATIENTS AND PARTICIPANTS: Adult patients with an intubation period exceeding 24 h were included. INTERVENTIONS: Patients received either routine endotracheal suctioning (RES) or minimally invasive airway suctioning (MIAS) during the duration of intubation. MEASUREMENTS AND RESULTS: Within 3 days after ICU discharge all patients were interviewed, regarding recollection and discomfort of suctioning. The level of discomfort was quantified on a visual analogue scale (VAS). We analyzed data from 208 patients (RES: n=113, and MIAS: n=95). A significantly lower prevalence of recollection of airway suctioning was found in the MIAS group (20%) compared to the RES group (41%) (P-value =0.001). No significant difference in level of discomfort was found between the RES and the MIAS group (P-value =0.136). CONCLUSIONS: Minimally invasive airway suctioning results in a lower prevalence of recollection of airway suction than in RES, but not in discomfort.     

不同吸痰方式对ARDS犬肺内气体交换影响的实验研究

目的研究开放式气管内吸痰(OS)和密闭式气管内吸痰(CS)对急性呼吸窘迫综合征(ARDS)犬肺内气体交换的影响,选择更适宜ARDS犬气管内吸痰的方式。方法采用静脉注射油酸制备16只犬ARDS模型,每只犬随机选择使用OS和CS两种吸痰方式,于吸痰前后抽取动脉血和混合静脉血进行血气分析。结果OS后,犬动脉血氧分压(PaO2)、动脉血氧饱和度(SaO2)、氧合指数(PaO2/FiO2)明显降低,肺泡-动脉血氧分压差(PA-aO2)明显增大(P<0.05);CS前后PaO2、SaO2等指标变化无显著性差异(P>0.05)。结论OS加重ARDS犬低氧血症;CS对ARDS犬肺内气体交换影响小,ARDS犬吸痰时选择CS方式更适宜和安全。     

Physiological responses to endotracheal and oral suctioning in paediatric patients: the influence of endotracheal tube sizes and suction pressures.

OBJECTIVE: To study the influence of varying outer suction catheter (SC) diameter (OD) to inner endotracheal tube (ETT) diameter (ID) and suction pressures (SP) on heart rate (HR), respiratory rate (RR), mean arterial pressure (MAP), arterial oxygen saturation (SaO 2) and intracranial pressure (ICP) during ETT and oral suctioning. An additional aim was to define an optimal suction catheter size that would prove easy to introduce and be rapidly effective in clearing secretions with the least physiological alteration. DESIGN: Prospective study. SETTING: Paediatric intensive care unit. PATIENTS: Ventilated paediatric patients. INTERVENTION: Patients had ETT suctioning performed in a random fashion using suction catheters with SC outer diameter to inner ETT diameter of approximately 0.4, 0.7 and 0.9 using varying pressures (80, 100, 120 mmHg). Using the medium size suction catheter (OD/ID = 0.7) at 100 mmHg of suction pressure, oral suctioning was compared to ETT suctioning. MEASUREMENTS AND MAIN RESULTS: Seventeen patients were studied (age 6.5 + 5 months). All suction catheters at varying pressures resulted in similar transient alterations in HR, RR, MAP, SaO 2 and ICP following ETT suctioning. Significant changes were seen in SaO 2, HR and ICP, irrespective of the catheter diameter or suction pressure. Oral suctioning resulted in similar trends and magnitude of changes as for ETT suctioning in MAP, RR, HR, and ICP, but less change occurred in the SaO 2 (p less than 0.05). The catheters with OD/ID of 0.7 were easiest to introduce and most effective in clearing secretions. CONCLUSION: Our study suggests that: 1. Tracheal toilet using variations in OD/ID ratios and SP within limits tested resulted in similar significant adverse changes in HR, ICP and SaO 2 and similar trends in RR and MAP. 2. Based on the ease of introduction and the effectiveness of clearing secretions, a medium SC (OD/ID = 0.7) is most appropriate for infants and children. 3. Oral suctioning also results in adverse physiological changes, therefore similar precautions to those taken during tracheal suctioning should be followed for oral suctioning.     

Effects of expiratory rib-cage compression on oxygenation, ventilation, and airway-secretion removal in patients receiving mechanical ventilation

BACKGROUND: Expiratory rib-cage compression, a chest physiotherapy technique, is well known as the "squeezing" technique in Japan. OBJECTIVE: To determine the effects of rib-cage compression on airway-secretion removal, oxygenation, and ventilation in patients receiving mechanical ventilation. SETTING: An intensive care unit of an emergency and critical care center at a tertiary-care teaching hospital in Tokyo, Japan. METHODS: Thirty-one intubated, mechanically ventilated patients in an intensive care unit were studied in a randomized, crossover trial. The patients received endotracheal suctioning with or without rib-cage compression, with a minimum 3-hour interval between the 2 interventions. Rib-cage compression was performed for 5 min before endotracheal suctioning. Arterial blood gas and respiratory mechanics were measured 5 min before endotracheal suctioning (baseline) and 25 min after suctioning. The 2 measurement periods were carried out on the same day. RESULTS: There were no significant differences in the ratio of arterial partial pressure of oxygen to fraction of inspired oxygen, P(aCO2), or dynamic compliance of the respiratory system between the 2 periods (before and after endotracheal suctioning). Moreover, there were no significant differences in airway-secretion removal between the 2 periods. CONCLUSIONS: This study suggests that rib-cage compression prior to endotracheal suctioning does not improve airway-secretion removal, oxygenation, or ventilation after endotracheal suctioning in this unselected population of mechanically ventilated patients.     

The impact of endotracheal suctioning on gas exchange and hemodynamics during lung-protective ventilation in acute respiratory distress syndrome

OBJECTIVE: To evaluate the respiratory and hemodynamic effects of open suctioning (OS) versus closed suctioning (CS) during pressure-control (PC) and volume-control (VC) ventilation, using a lung-protective ventilation strategy in an animal model of acute respiratory distress syndrome (ARDS). SETTING: Animal laboratory in a university hospital. DESIGN: Randomized cross-over evaluation. ANIMALS: Eight female Dorset sheep. INTERVENTIONS: Lung lavage was used to simulate ARDS. We applied VC and PC mechanical ventilation with a tidal volume of 6 mL/kg and positive end-expiratory pressure (PEEP), adjusted based on a table of PEEP versus fraction of inspired oxygen (FIO2). Suctioning was performed for 10 s with a suction pressure of -100 mm Hg, during both OS and CS. OS and CS were randomly performed with each animal. Hemodynamics and arterial blood gases were recorded before, during, and after endotracheal suctioning. RESULTS: The PaO2/FIO2 ratios before suctioning were similar in all groups, as were the PEEP and FIO2. PaO2/FIO2 was lower after OS than after CS/VC or CS/PC. There was no post-suctioning difference in oxygenation between CS/VC and CS/PC. PaCO2 recorded 10 min after suctioning was greater than the presuctioning value, in all groups. Intrapulmonary shunt fraction increased between baseline and 10 min post-suctioning with OS and CS/VC, but did not significantly increase with CS/PC. There were no significant changes in hemodynamics pre-suctioning versus post-suctioning with OS, CS/VC, or CS/PC. CONCLUSION: PaO2/FIO2) was better maintained during CS with both VC and PC modes during lung-protective ventilation for ARDS, as compared with OS, and shunt fraction post-suctioning changed least with PC.     

滴注NaCl湿化液对机械通气新生儿吸痰效果及心肺功能的影响

目的探讨机械通气新生儿吸痰前气道内滴注不同容量、浓度的NaCl湿化液对痰量和心肺功能的影响。方法选择20例有创机械通气新生儿,分别给予气道内滴注不同容量、浓度的NaCl湿化液,记录滴注湿化液后和吸痰后1,2,10min的痰量和外周血氧饱和度（SpO2）、气道峰压（PIP）、心率（HR）、收缩压（SBP）和舒张压（DBP）。结果滴注0.5ml湿化液组的痰液排出量（1.27±0.77）ml与不滴注湿化液组的痰液排出量（0.74±0.55）ml比较,差异有统计学意义（P=0.006）,但与滴注1ml湿化液组的痰液排出量（0.99±0.66）ml比较,差异无统计学意义（P=0.072）。在气管内吸痰前滴注不同浓度（0.9%和0.45%）、不同容量（0.5ml和1ml）NaCl湿化液对痰液排出量的影响无统计学差异（P＞0.05）。不同浓度和容量的NaCl湿化液对SpO2、HR、PIP、SBP和DBP均无影响（P＞0.05）,但SpO2、HR和SBP在吸痰前后均有随时间变化的趋势（F值分别为41.567,39.688,6.715,P＜0.05）。吸痰后2,10min的SpO2高于滴注湿化液后和吸痰后1min;吸痰后1,2min的HR快于滴注湿化液后;吸痰后1,2min的SBP较滴注湿化液后增高;PIP和DBP在吸痰前后没有随时间变化的趋势。结论机械通气新生儿吸痰前气道内滴注0.5ml、0.9%NaCl湿化液,可以增加痰量,对心肺功能无明显不良影响。