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BJA Advance Access originally published online on February 4, 2008
British Journal of Anaesthesia 2008 100(3):299-306; doi:10.1093/bja/aem403
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© The Board of Management and Trustees of the British Journal of Anaesthesia 2008. All rights reserved. For Permissions, please e-mail: journals.permissions@oxfordjournals.org

Closed tracheal suction systems for prevention of ventilator-associated pneumonia

I. I. Siempos1, K. Z. Vardakas1 and M. E. Falagas1,2,3,*

1 Alfa Institute of Biomedical Sciences (AIBS), 9 Neapoleos Street, 151 23 Marousi, Athens, Greece
2 Department of Medicine, Henry Dunant Hospital, Athens, Greece
3 Department of Medicine, Tufts University School of Medicine, Boston, MA, USA

* Corresponding author. Alfa Institute of Biomedical Sciences (AIBS), 9 Neapoleos Street, 151 23 Marousi, Athens, Greece. E-mail: m.falagas{at}aibs.gr


   Abstract
Top
 Abstract
Introduction
 Methods
 Results
 Discussion
 References
 
We have assessed the evidence that closed tracheal suction systems (TSS) prevent ventilator-associated pneumonia (VAP), using a meta-analysis of randomized controlled trials (RCTs). We searched PubMed and Cochrane databases to identify RCTs that compared closed with open TSS for the management of mechanically ventilated (MV) patients. Nine RCTs were included in the meta-analysis. There was no difference in the incidence of VAP between patients managed with closed and open TSS [odds ratio (OR)=0.96, 95% confidence intervals (CI) 0.72–1.28]. There was no heterogeneity among the eligible trials (I2=0, 95% CI 0–0.65). The compared groups did not differ with respect to mortality (OR=1.04, 95% CI 0.78–1.39) or intensive care unit (ICU) length of stay [two RCTs: 12.3 (SD 1.1) vs 11.5 (1.4) days and 15.6 (13.4) vs 19.9 (16.7) days]. Suctioning with closed systems was associated with longer MV duration (weighted mean differences: 0.65 days, 95% CI 0.28–1.03) and higher colonization of the respiratory tract (OR=2.88, 95% CI 1.50–5.52) than open TSS. The available evidence suggests that closed as opposed to open TSS usage did not provide any benefit on VAP incidence, mortality, or ICU stay of MV patients.

Keywords: complications, infection; equipment, tubes suction; infection, bacterial


   Introduction
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 Abstract
 Introduction
Methods
 Results
 Discussion
 References
 
Between 8% and 28% of patients receiving mechanical ventilation (MV) in the intensive care unit (ICU) can contract ventilator-associated pneumonia (VAP),6 30 which increases mortality and morbidity.17 36 37 Several techniques for the management of MV patients have been employed to reduce the risk for the development of VAP.

Among the most common supportive measures for MV patients is the endotracheal suctioning, performed with either closed multi-use catheter tracheal suction systems (TSS) or open single-use catheter TSS. Although preliminary studies reported that closed TSS reduced the risk of developing a respiratory infection, the comparative effectiveness over open TSS for prevention of VAP remains controversial. Branson3 recently stated that the conventional wisdom that fewer breaks of the circuit results in a lower risk of contamination clearly supports the employment of closed TSS. Subsequently, Craven10 stated that the use of closed TSS as a preventive measure is optional, even though three randomized controlled trials (RCTs) showed no effect on VAP.

It seems that although the use of closed TSS is considered for the prevention of VAP, scepticism exists about their usefulness. Thus, to assess the comparative effectiveness of closed over open TSS for the prevention of VAP in critically ill patients, we conducted a meta-analysis of the published RCTs on the topic.


   Methods
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 Abstract
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 Methods
Results
 Discussion
 References
 
We used guidelines from the Quality of Reporting of Meta-Analyses conference.26 We searched systematically the PubMed (up to September 2007) and the Cochrane Central Register of Controlled Trials by using the following key terms: ‘ventilator-associated pneumonia’ or ‘ventilator associated pneumonia’ or ‘nosocomial pneumonia’ and ‘suction’ or ‘suctioning’. We additionally reviewed the references of the selected articles. We did not seek for abstracts presented in scientific conferences.

Two reviewers (I.I.S. and K.Z.V.) independently performed the literature search. A RCT was considered eligible, if (a) it examined the role of closed TSS in comparison with open TSS for the management of patients receiving MV and (b) it reported on the incidence of VAP. Only RCTs conducted in adult patients and written in English, French, or German were included in the analysis. In contrast, we omitted trials focusing on special issues of endotracheal suctioning (e.g. the frequency of change of closed TSS catheter), trials comparing different types of closed TSS, and trials evaluating only the effects on gas exchange and haemodynamics.

Two reviewers (I.I.S. and K.Z.V.) independently extracted the data from all eligible articles: year of publication, study design, study population, severity of illness on ICU admission, brand of closed TSS used, co-interventions, and criteria used in each of the selected RCTs for the definition of VAP. Incidence of VAP, mortality, length of ICU stay, duration of MV, colonization of the respiratory tract, and cost associated with TSS usage were recorded. Any disagreement between the two reviewers was resolved by the consensus of all authors. We also independently rated the methodological quality of each RCT by using a modified Jadad score.19 27 We assessed the following components: randomization, generation of random numbers, details of double-blinding procedure, information on withdrawals, and concealment of allocation. One point was awarded for the specification of each criterion; the maximum score for a study is 5. Finally, we collected information on the source of funding of the eligible RCTs, because it has been found that industry-funded studies are more likely to have positive results.

Analysed outcomes
The primary outcome for this meta-analysis was the incidence of VAP (until patient’s death or discharge from the ICU) for all patients included in the selected RCTs. All-cause mortality, length of ICU stay, duration of MV, colonization of the respiratory tract, and cost associated with the usage of these systems were regarded as secondary outcomes.

Definitions
Ventilator-associated pneumonia
Pneumonia was defined by clinical, laboratory, and imaging findings attributed by the authors of the trials to this infection. To be considered as ventilator-associated, the above findings of pneumonia should be present in patients receiving MV for at least 48 h.

Colonization of the respiratory tract
Colonization was defined by the isolation of one or more micro-organisms from sputum or bronchial secretions of the patients without accompanying evidence of infection of the respiratory tract.

Data analysis and statistical methods
Statistical analyses were performed using the ‘S-PLUS 6.1’ software. The heterogeneity between RCTs was assessed by using both a {chi}2 test (a P-value lower than 0.10 was defined to note statistical significance) and the I2 statistic. Publication bias was assessed by the funnel plot method using Egger’s test.15 Continuous outcomes were analysed using weighted mean differences (WMDs) and 95% confidence intervals (CI). Pooled odds ratios (OR) and 95% CI for the outcomes of this meta-analysis were calculated by using the DerSimonian–Laird13 random effects model.


   Results
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 Abstract
 Introduction
 Methods
 Results
Discussion
 References
 
Selected RCTs
The electronic database search yielded 23 potentially relevant RCTs; three more RCTs that were not captured in the initial search were found through the review of the references of the relevant articles. From these, 17 reports were retrieved for further evaluation. Eight9 11 22 23 31 33 34 41 out of the 17 RCTs were omitted for the reasons detailed in Figure 1. Finally, nine RCTs1 8 12 20 24 25 29 38 42 were considered eligible for our meta-analysis.


Figure 1
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  		Fig 1 Flow diagram of reviewed articles. RCT, randomized controlled trial; VAP, ventilator-associated pneumonia.

 
Characteristics of the selected studies
For the nine RCTs1 8 12 20 24 25 29 38 42 included in the meta-analysis (Table 1), the quality score for five trials1 8 20 38 42 was 1 and for the other four12 24 25 29 trials was 2. One of the selected RCTs enrolled orthotopic liver transplant patients for chronic liver failure,1 whereas the other RCTs8 12 20 24 25 29 38 42 included immunocompetent patients. The compared groups of patients (i.e. those managed with closed and those managed with open TSS) were similar at the time of randomization with respect to demographic characteristics and severity of illness (Table 1) in each of those included in the meta-analysis RCTs. In the majority of the eligible RCTs,1 8 12 20 38 42 diagnosis of VAP was based on clinical, laboratory, and imaging findings, whereas in three RCTs24 25 29 quantitative cultures were also required for the microbiological confirmation of the VAP.


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  		Table 1 Main characteristics of the RCTs included in the meta-analysis (comparison of a closed vs an open TSS). ICU, intensive care unit; VAP, ventilator-associated pneumonia; SD, standard deviation; RCT, randomized controlled trial; MV, mechanical ventilation; AIDS, acute immunodeficiency syndrome; APACHE, acute physiology and chronic health evaluation; SAPS, simplified acute physiology score; NA, not available/applicable; SRBP, semirecumbent body position; CEN, continuous enteral nutrition; SDD, selective digestive decontamination; CASS, continuous aspiration of subglottic secretions; HMEs, heat-and-moisture exchangers; PPIs, proton pump inhibitors; T, temperature; WBC, white blood cell count; TA, tracheal aspirates; BAL, brochoalveolar lavage; PSB, protected brush specimen. *According to a modified Jadad score. {dagger}According to the authors. {ddagger}Median of the parameter measured rather than mean (SD) was reported in this RCT. APACHE II score was available only for the medical patients (not for the surgical patients) in this RCT

 
In seven1 8 12 20 25 29 42 of the selected RCTs, the catheter of the closed TSS was replaced every 24 h, whereas in the remaining two RCTs,24 38 the catheter was changed only when it was grossly contaminated with secretions or its integrity was disrupted. Frequency of endotracheal suctioning was at nurse’s discretion in the seven RCTs1 8 12 20 24 25 29 that provided specific data on this issue. Information on interventions other than endotracheal suctioning for the management of MV patients was mentioned in eight1 8 12 24 25 29 38 42 of the selected RCTs (Table 1).

Six trials1 8 24 25 38 42 did not provide any details of the source of funding, one trial29 reported that no funding was granted, another RCT20 was supported by a grant from the University, and the remaining RCT12 was, in part, industry-funded.

Incidence of VAP
All the RCTs included in the meta-analysis reported outcomes on the incidence of VAP (Table 2).1 8 12 20 24 25 29 38 42 There was no heterogeneity among the identified comparisons (P=0.49, I2=0, 95% CI 0–0.65). Publication bias was not detected (Egger’s test P=0.08). There was no difference in the incidence of VAP between patients suctioned with closed or open TSS (OR=0.96, 95% CI 0.72–1.28). The OR for VAP incidence in the individual RCTs, and the pooled OR, are in Figure 2.


Figure 2
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  		Fig 2 OR of incidence of VAP for the individual RCTs comparing closed and open TSS for the management of patients under MV and the pooled analysis.

 


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  		Table 2 Outcome data from the selected RCTs for the meta-analysis (closed vs open TSS). VAP, ventilator-associated pneumonia; ICU, intensive care unit; SD, standard deviation; MV, mechanical ventilation. *It is referred to Euros rather than USD$ in this RCT. {dagger}It is referred to colonization of the ventilator tubing rather than colonization of patients’ trachea. Ventilator tubing cultures were not obtained from all patients included in this RCT. {ddagger}It is referred to £ rather than USD$ in this RCT

 
Subgroup analyses
First, a subgroup analysis was conducted after the exclusion of the RCT that enrolled immunocompromised patients who received ICU care after liver transplantation.1 Performance of closed TSS in immunocompetent MV patients was not associated with lower VAP incidence compared with open TSS (OR=0.95, 95% CI 0.70–1.29, data from eight RCTs8 12 20 24 25 29 38 42). Likewise, there was no difference between the compared TSS regarding VAP incidence in the both subset analyses of studies published after (OR=0.99, 95% CI 0.64–1.51, data from five RCTs24 25 29 38 42) and before (OR=0.73, 95% CI 0.38–1.40, data from four RCTs1 8 12 20) the year 2003.

Secondary outcomes
Mortality
Five of the RCTs included in the meta-analysis reported on all-cause mortality.8 12 24 25 38 Heterogeneity among the comparisons (P=0.94, I2=0, 95% CI 0–0.79) and publication bias (Egger’s test P=0.47) were not found. Mortality was not different between patients managed with closed or open TSS (OR=1.04, 95% CI 0.78–1.39).

Length of ICU stay
Data regarding the length of ICU stay were available for two8 38 RCTs included in this meta-analysis. In both, there was no difference between the compared groups regarding ICU length of stay (Table 2).

Duration of MV
Five1 8 24 25 38 RCTs reported on duration of MV. Suctioning with closed as opposed to open TSS was associated with longer MV duration (WMDs: 0.65 days, 95% CI 0.28–1.03).

Colonization of the respiratory tract
Four1 12 29 38 RCTs provided data with regard to the colonization of the respiratory tract. Heterogeneity (P=0.52, I2=0, 95% CI 0–0.85) and publication bias (Egger’s test P=0.85) were not detected. More patients were colonized in the group managed with closed TSS compared with the group of patients managed with open TSS (OR=2.88, 95% CI 1.50–5.52). Regarding the potentially pathogenic micro-organisms causing colonization, specific data were provided in three1 29 38 of these RCTs. Colonization with Acinetobacter spp. or Pseudomonas aeruginosa was reported only in one RCT,38 colonization rates with these microbes were more frequent in the closed suction group than in the open suction group (P<0.01 and P=0.01, respectively) (data not shown).

Cost
Data regarding the cost associated with each suction system were available for four RCTs.1 20 24 25 In two1 25 of these RCTs, the use of closed TSS was associated with higher cost than open TSS, whereas the remaining two RCTs20 24 reported no difference between the compared TSS regarding cost (Table 2).


   Discussion
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 Abstract
 Introduction
 Methods
 Results
 Discussion
References
 
The results of this meta-analysis suggest that there is no difference between MV patients managed with closed TSS and those managed with open TSS in terms of incidence of VAP, mortality, or ICU length of stay. The findings of our study are supported by those of two28 32 reports not included in this meta-analysis; one of these reports was excluded because it was not a RCT32 and the other because it was only presented as an abstract.28 Both studies reported a similar risk for nosocomial pneumonia in both closed and open TSS.

Interestingly, the relevant guidelines seem to be inconclusive on the usefulness of closed TSS in preventing VAP in MV patients. In the most recent guidelines for preventing health-care-associated pneumonia published (2004) by the Centres for Disease Control and Prevention, the preferential use of either the closed TSS or the open TSS for VAP prevention was considered as an unresolved issue.36 On the other hand, the Canadian Critical Care Trials Group and the Canadian Critical Care Society (2004) concluded that type of TSS (closed or open) has no effect on VAP incidence; however, they encouraged the use of closed TSS based on cost considerations.14 A year earlier (2003), the American Association for Respiratory Care’s recommendation regarding this issue was that closed TSS should be considered part of a VAP prevention strategy.18 Finally, the European Task Force on VAP (2001) mentioned that there is only limited evidence that closed TSS usage is able to reduce VAP incidence at the expense of a clearly increased cost and, thus, no recommendation has been made.39

The comparison of the various TSS with regard to physiological consequences and feasibility was not the focus of this meta-analysis. It has been demonstrated that adoption of closed rather than open TSS results in the avoidance of effects, such as decreased arterial pressure,20 cardiac arrhythmias,20 elevated intracranial pressure,4 and arterial oxygen desaturation5 during suctioning. Although Johnson and colleagues20 reported that closed tracheal suctioning requires less nursing time than open, another study found that ICU staff experienced some difficulties when using closed TSS.2 Finally, closed TSS has been found to decrease environmental contamination.7 The latter seems to be the main advantage of closed over open TSS.10

However, the use of closed TSS has been blamed for higher levels of colonization;16 32 a concern that was confirmed by this meta-analysis. Indeed, in two12 38 of the RCTs included in the meta-analysis, closed TSS were found to increase colonization of the respiratory tract12 and of the ventilator tubing,38 respectively.

The four1 20 24 25 trials included in our meta-analysis that evaluated the cost associated with TSS reported conflicting results. Two1 25 of these trials found a higher cost in respiratory secretions’ suctioning with the use of closed TSS than with open ones, whereas the other two20 24 found no difference. However, one20 was published in 1994, and therefore the cost data are now out of date. In the other,24 the cost of closed TSS was presumably reduced by the avoidance of routine (every 24 h) in-line suction catheter changes.35 Indeed, relevant guidelines agree that closed TSS catheters should be replaced only when it is clinically indicated.14 18 39

The present meta-analysis is not without limitations. First, there are relatively few trials to review and none was blinded; thus, one might postulate that our analysis may be not powered enough to detect a difference between the two techniques of endotracheal suctioning. However, we deliberately chose to include only RCTs, which are considered to provide the most methodologically rigorous evidence, and we accepted the lack of blindness as inevitable in this case due to the nature of the intervention. Secondly, the criteria used for the definition of VAP were not identical in the investigations included in this meta-analysis. Therefore, this may have introduced significant confounding. Thirdly, the differences in the populations studied in the selected RCTs may also confound the results of any meta-analysis of VAP. Thus, we performed a subgroup analysis by excluding the RCT that enrolled only liver-transplant patients.1 Finally, the fact that the included trials were conducted in different time periods and, thus, routine care and co-interventions for VAP prevention may be not identical may also introduce problems in the interpretation of the findings and their application. However, subgroup analyses were again performed by pooling data from trials before1 8 12 20 and after24 25 29 38 42 2003.

The findings of this meta-analysis corroborate those of two very recently analyses that investigated the use of closed vs open TSS.21 40 The first analysis was limited to the evaluation of the impact on the incidence of VAP,40 whereas the other focused mainly on the cardiorespiratory effects in MV patients.21 Our contribution differs in that it also includes analysis of duration of MV, specific data on the length of ICU stay, and the kind of micro-organisms causing colonization. This additional information, in combination with the above studies, permits a more comprehensive estimation of the different techniques of endotracheal suctioning.

In conclusion, the use of closed TSS is not associated with lower incidence of VAP or mortality compared with open TSS. We should emphasize that as this intervention has been proved not to be harmful, further investigation is warranted to clarify its potential value in decreasing environmental spread of multi-drug resistant pathogens, an issue of major importance.


   References
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 References
 
1 Adams DH, Hughes M, Elliott TS. Microbial colonization of closed-system suction catheters used in liver transplant patients. Intensive Crit Care Nurs (1997) 13:72–6.[CrossRef][Medline]

2 Blackwood B, Webb CH. Closed tracheal suctioning systems and infection control in the intensive care unit. J Hosp Infect (1998) 39:315–21.[CrossRef][Web of Science][Medline]

3 Branson RD. The ventilator circuit and ventilator-associated pneumonia. Respir Care (2005) 50:774–85.[Medline]

4 Brucia J, Rudy E. The effect of suction catheter insertion and tracheal stimulation in adults with severe brain injury. Heart Lung (1996) 25:295–303.[CrossRef][Web of Science][Medline]

5 Carlon GC, Fox SJ, Ackerman NJ. Evaluation of a closed-tracheal suction system. Crit Care Med (1987) 15:522–5.[Web of Science][Medline]

6 Chastre J, Fagon JY. Ventilator-associated pneumonia: state of the art. Am J Respir Crit Care Med (2002) 165:867–903.[Abstract/Free Full Text]

7 Cobley M, Atkins M, Jones PL. Environmental contamination during tracheal suction. A comparison of disposable conventional catheters with a multiple-use closed system device. Anaesthesia (1991) 46:957–61.[Web of Science][Medline]

8 Combes P, Fauvage B, Oleyer C. Nosocomial pneumonia in mechanically ventilated patients, a prospective randomised evaluation of the Stericath closed suctioning system. Intensive Care Med (2000) 26:878–82.[CrossRef][Web of Science][Medline]

9 Cordero L, Sananes M, Ayers LW. Comparison of a closed (TrachCareTM) with an open endotracheal suction system in small premature infants. J Perinatol (2000) 20:151–6.[CrossRef][Medline]

10 Craven DE. Preventing ventilator-associated pneumonia in adults: sowing seeds of change. Chest (2006) 130:251–60.[CrossRef][Web of Science][Medline]

11 Darvas JA, Hawkins LG. The closed tracheal suction catheter: 24 hour or 48 hour change? Aust Crit Care (2003) 16:86–92.[CrossRef][Medline]

12 Deppe SA, Kelly JW, Thoi LL, et al. Incidence of colonization, nosocomial pneumonia, and mortality in critically ill patients using a Trach Care closed-suction system versus an open-suction system: prospective, randomized study. Crit Care Med (1990) 18:1389–93.[Web of Science][Medline]

13 DerSimonian R, Laird N. Meta-analysis in clinical trials. Control Cllin Trials (1986) 7:177–88.[CrossRef]

14 Dodek P, Keenan S, Cook D, et al. Evidence-based clinical practice guideline for the prevention of ventilator-associated pneumonia. Ann Intern Med (2004) 141:305–13.[Abstract/Free Full Text]

15 Egger M, Davey SG, Schneider M, Minder C. Bias in meta-analysis detected by a simple, graphical test. Br Med J (1997) 315:629–34.[Abstract/Free Full Text]

16 Freytag CC, Thies FL, Konig W, Welte T. Prolonged application of closed in-line suction catheters increases microbial colonization of the lower respiratory tract and bacterial growth on catheter surface. Infection (2003) 31:31–7.[CrossRef][Web of Science][Medline]

17 Girou E, Stephan F, Novara A, Safar M, Fagon JY. Risk factors and outcome of nosocomial infections: results of a matched case-control study of ICU patients. Am J Respir Crit Care Med (1998) 157:1151–8.[Abstract/Free Full Text]

18 Hess DR, Kallstrom TJ, Mottram CD, Myers TR, Sorenson HM, Vines DL, American Association for Respiratory Care. Care of the ventilator circuit and its relation to ventilator associated pneumonia. Respir Care (2003) 48:869–79.[Medline]

19 Jadad AR, Moore RA, Carroll D, et al. Assessing the quality of reports of randomized clinical trials: is blinding necessary? Control Clin Trials (1996) 17:1–12.[CrossRef][Web of Science][Medline]

20 Johnson KL, Kearney PA, Johnson SB, Niblett JB, MacMillan NL, McClain RE. Closed versus open endotracheal suctioning: costs and physiologic consequences. Crit Care Med (1994) 22:658–66.[Web of Science][Medline]

21 Jongerden IP, Rovers MM, Grypdonck MH, Bonten MJ. Open and closed endotracheal suction systems in mechanically ventilated intensive care patients: a meta-analysis. Crit Care Med (2007) 35:260–70.[CrossRef][Web of Science][Medline]

22 Kollef MH, Prentice D, Shapiro SD, et al. Mechanical ventilation with or without daily changes of in-line suction catheters. Am J Respir Crit Care Med (1997) 156:466–72.[Abstract/Free Full Text]

23 Lee ES, Kim SH, Kim JS. Effects of a closed endotracheal suction system on oxygen saturation, ventilator-associated pneumonia, and nursing efficacy. Taehan Kanho Hakhoe Chi (2004) 34:1315–25.[Medline]

24 Lorente L, Lecuona M, Jimenez A, Mora ML, Sierra A. Tracheal suction by closed system without daily change versus open system. Intensive Care Med (2006) 32:538–44.[CrossRef][Web of Science][Medline]

25 Lorente L, Lecuona M, Martin M, Garcia C, Mora M, Sierra A. Ventilator-associated pneumonia using a closed versus an open tracheal suction system. Crit Care Med (2005) 33:115–9.[CrossRef][Web of Science][Medline]

26 Moher D, Cook DJ, Eastwood S, Olkin I, Rennie D, Stroup DF, for the QUOROM group. Improving the quality of reports of meta-analyses of randomized controlled trials: the QUOROM statement. Lancet (1999) 354:1896–900.[CrossRef][Web of Science][Medline]

27 Moher D, Jones A, Cook DJ, et al. Does quality of reports of randomised trials affect estimates of intervention efficacy reported in meta-analyses? Lancet (1998) 352:609–13.[CrossRef][Web of Science][Medline]

28 Prentice D, Weilitz PB, Fraser VJ. A prospective randomized trial comparing outcomes of a closed versus open suctioning system (abstract). Crit Care Med (1994) 22:A92.

29 Rabitsch W, Kostler WJ, Fiebiger W, et al. Closed suctioning system reduces cross-contamination between bronchial system and gastric juices. Anesth Analg (2004) 99:886–92.[Abstract/Free Full Text]

30 Rello J, Rue M, Jubert P, et al. Survival in patients with nosocomial pneumonia: impact of the severity of illness and the etiologic agent. Crit Care Med (1997) 25:1862–7.[CrossRef][Web of Science][Medline]

31 Ridling DA, Martin LD, Bratton SL. Endotracheal suctioning with or without instillation of isotonic sodium chloride solution in critically ill children. Am J Crit Care (2003) 12:212–9.[Abstract/Free Full Text]

32 Ritz R, Scott LR, Coyle MB, Pierson DJ. Contamination of a multiple-use suction catheter in a closed-circuit system compared to contamination of a disposable, single-use suction catheter. Respir Care (1986) 31:1087–91.

33 Sanver A, Topeli A, Cetinkaya Y, Kocagoz S, Unal S. Comparison of closed with open tracheal aspiration system. Crit Care (2001) 5:52.[CrossRef]

34 Silva LD. A infecção pulmonar no contexto da UTI: uma contribuição para sua prevenção attravés do sistema de aspiração traqueal empregado pela enfermagem. Revista de Enfermagem da Universidade Estadual Do Rio de Janeiro (1993) 1:24–30.

35 Stoller JK, Orens DK, Fatica C, et al. Weekly versus daily changes of in-line suction catheters: impact on rates of ventilator-associated pneumonia and associated costs. Respir Care (2003) 48:494–9.[Medline]

36 Tablan OC, Anderson LJ, Besser R, et al. Guidelines for preventing health-care-associated pneumonia, 2003: recommendations of the CDC and the Healthcare Infection Control Practices Advisory Committee. Morb Mortal Wkly Rep (2004) 53:1–36.[Medline]

37 The American Thoracic Society and the Infectious Diseases Society of America Guideline Committee. Guidelines for the management of adults with hospital-acquired, ventilator-associated, and healthcare-associated pneumonia. Am J Respir Crit Care Med (2005) 171:388–416.[Free Full Text]

38 Topeli A, Harmanci A, Cetinkaya Y, Akdeniz S, Unal S. Comparison of the effect of closed versus open endotracheal suction systems on the development of ventilator-associated pneumonia. J Hosp Infect (2004) 58:14–9.[CrossRef][Web of Science][Medline]

39 Torres A, Carlet J, the European Task Force on Ventilator Associated Pneumonia. Ventilator associated pneumonia. Eur Respir J (2001) 17:1034–45.[Free Full Text]

40 Vonberg RP, Eckmanns T, Welte T, Gastmeier P. Impact of suctioning system (open vs closed) on the incidence of ventilator-associated pneumonia: meta-analysis of randomized controlled trials. Intensive Care Med (2006) 32:1329–35.[CrossRef][Web of Science][Medline]

41 Zeitoun SS, de Barros AL, Diccini S, Juliano Y. Incidence of ventilator-associated pneumonia in patients using open-suction systems and closed-suction systems: a prospective study—preliminary data. Rev Lat Am Enfermagem (2001) 9:46–52.[Medline]

42 Zeitoun SS, de Barros AL, Diccini S. A prospective, randomized study of ventilator-associated pneumonia in patients using a closed vs. open suction system. J Clin Nurs (2003) 12:484–9.[CrossRef][Web of Science][Medline]


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