Prevention of ventilator-associated pneumonia through aspiration of subglottic secretions: a systematic review and meta-analysis

Effect of continuous measurement and adjustment of endotracheal tube cuff pressure on postoperative sore throat in patients undergoing gynecological laparoscopic surgery: a randomized controlled trial

BACKGROUND

Postoperative sore throat (POST) is a common complication following endotracheal tube removal, and effective preventive strategies remain elusive. This trial aimed to determine whether actively regulating intraoperative cuff pressure below the tracheal capillary perfusion pressure threshold could effectively reduce POST incidence in patients undergoing gynecological laparoscopic procedures.

METHODS

This single-center, randomized controlled superiority trial allocated 60 patients scheduled for elective gynecological laparoscopic procedures into two groups: one designated for cuff pressure measurement and adjustment (CPMA) group, and a control group where only cuff pressure measurement was conducted without any subsequent adjustments. The primary outcome was POST incidence at rest within 24 h post-extubation. Secondary outcomes included cough, hoarseness, postoperative nausea and vomiting (PONV) incidence, and post-extubation pain severity.

RESULTS

The incidence of sore throat at rest within 24 h after extubation in the CPMA group was lower than in the control group, meeting the criteria for statistically significant superiority based on a one-sided test (3.3% vs. 26.7%, P < 0.025). No statistically significant differences were observed in cough, hoarseness, or pain scores within 24 h post-extubation between the two groups. However, the CPMA group had a higher incidence of PONV compared to the control group. Additionally, the control group reported higher sore throat severity scores within 24 h post-extubation.

CONCLUSIONS

Continuous monitoring and maintenance of tracheal tube cuff pressure at 18 mmHg were superior to merely monitoring without adjustment, effectively reducing the incidence of POST during quiet within 24 h after tracheal tube removal in gynecological laparoscopic surgery patients.

TRIAL REGISTRATION

The study was registered at www.chictr.org.cn (ChiCTR2200064792) on 18/10/2022.

Effect of continuous measurement and adjustment of endotracheal tube cuff pressure on postoperative sore throat in patients undergoing gynecological laparoscopic surgery: study protocol for a randomized controlled trial

BACKGROUND

Postoperative sore throat (POST) is a common postoperative complication after endotracheal tube removal. There are still no effective preventive methods for POST. The aim of this trial is to confirm whether maintaining intraoperative cuff pressure below the tracheal capillary perfusion pressure could effectively reduce the incidence of POST among patients undergoing gynecological laparoscopic surgery.

METHODS

This study is a single-center, randomized, parallel-controlled, superiority trial with a 1:1 allocation ratio. Sixty patients whose age is between 18 and 65 years and scheduled for gynecological laparoscopic surgery will be randomized to the cuff pressure measurement and adjustment (CPMA) group and the only cuff pressure measurement without adjustment group (control group). The primary endpoint is the incidence of sore throat at rest within 24 h after extubation. The secondary endpoints include the incidence of cough, the incidence of hoarseness, the incidence of postoperative nausea and vomiting (PONV), POST, and pain intensity within 24 h after extubation. Blocked randomization will be conducted with a computer-generated central randomization online service. The blind method will be applied to subjects, data collectors, outcome evaluators, and statisticians. Outcome assessments will be performed at 0 h and 24 h post-extubation.

DISCUSSION

This randomized controlled study hypothesizes that cuff pressure is the primary influencing factor of POST. By continuous monitoring of endotracheal tube cuff pressure and maintaining it within the range of 18-22 mmHg compared with only continuous measurement without adjustment, it aims to prove that continuous measurement and adjustment of endotracheal tube cuff pressure could be effective in reducing the incidence of POST in gynecological laparoscopic surgery patients. The result of this study could be used as a reference for future multicenter studies to confirm the effect of cuff pressure on POST and provides a scientific theoretical basis for preventing POST to further support comfort medicine.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2200064792. Registered on 18 October 2022. This protocol (version 1.0, 16 March 2022) was approved by the Ethics Committee of Beijing Chaoyang Hospital.

Airway and Respiratory Devices in the Prevention of Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) is the most common ICU-acquired infection among patients under mechanical ventilation (MV). It may occur in up to 50% of mechanically ventilated patients and is associated with an increased duration of MV, antibiotic consumption, increased morbidity, and mortality. VAP prevention is a multifaceted priority of the intensive care team. The use of specialized artificial airways and other devices can have an impact on the prevention of VAP. However, these devices can also have adverse effects, and aspects of their efficacy in the prevention of VAP are still a matter of debate. This article provides a narrative review of how different airway and respiratory devices may help to reduce the incidence of VAP.

Pulmonary Infections, Including Ventilator-Associated Pneumonia

Pneumonia is a leading cause of morbidity and mortality and a primary cause of hospitalizations. Guidelines have been established through the American Thoracic Society and Infectious Diseases Society of America in 2016 focusing on the causative pathogen for antibiotic selection. In 2017 an International European task force provided guidelines of specific antibiotic selections based on drug resistance and mortality risk. Improving patient outcomes is based not only on the appropriate treatment, which should not be delayed, but also on implementation and adherence to evidence-based strategies to reduce the increased risk of mortality.

Subglottic secretion drainage for preventing ventilator-associated pneumonia: an overview of systematic reviews and an updated meta-analysis

Although several guidelines recommend subglottic secretion drainage as a strategy for prevention of ventilator-associated pneumonia (VAP), its use is not widespread. With the aim to assess the effectiveness of subglottic secretion drainage for preventing VAP and to improve other outcomes such as mortality, duration of mechanical ventilation and length of stay in the intensive care unit (ICU) or hospital, an electronic search of the Cochrane Library, MEDLINE, Web of Science and Embase was undertaken. Nine systematic reviews with meta-analysis (in the overview of reviews) and 20 randomised controlled trials (in the updated meta-analysis) were included.

In the overview of reviews, all systematic reviews with meta-analysis included found a positive effect of subglottic secretion drainage in the reduction of incidence of VAP. In the updated meta-analysis, subglottic secretion drainage significantly reduced VAP incidence (risk ratio (RR) 0.56, 95% CI 0.48–0.63; I²=0%, p=0.841) and mortality (RR 0.88, 95% CI 0.80–0.97; I²=0%, p=0.888).

This is the first study that has found a decrease of mortality associated with the use of subglottic secretion drainage. In addition, subglottic secretion drainage is an effective measure to reduce VAP incidence, despite not improving the duration of mechanical ventilation and ICU and/or hospital length of stay.

Subglottic secretion drainage is an effective measure to reduce mortality and VAP incidence, despite not improving the duration of mechanical ventilation or length of stay in ICU and/or hospital.http://bit.ly/2PeJLR1

Subglottic secretion drainage for ventilator-associated pneumonia prevention: an underused efficient measure

Subglottic secretion drainage (SSD) is one of the recommended strategies to prevent ventilator-associated pneumonia (VAP) with a high level of evidence, especially regarding early-onset pneumonia. All meta-analysis found that the use of SSD reduces VAP occurrence with a relative risk (RR) reduction of 45%. In some of them, SSD reduces the duration of mechanical ventilation (MV) but without beneficial effect on intensive care unit (ICU) or hospital mortality. In spite of the edited recommendations, SSD has not been widely implemented in ICUs and remains underused. Several factors could account for this: doubts on the innocuousness of using SSD, persisting reservations on the SSD effect on other outcomes than VAP, a high variability in the volume of secretions suctioned between patients and, for each individual patient, during the period of MV and the initial increased expense of the specific endotracheal tubes (ETs) allowing SSD which limits the availability of these devices.

Subglottic secretion suction for preventing ventilator-associated pneumonia: an updated meta-analysis and trial sequential analysis

Background

Potential benefits of subglottic secretion suction for preventing ventilator-associated pneumonia (VAP) are not fully understood.

Methods

We searched Cochrane Central, PubMed, and EMBASE up to March 2016 to identify randomized controlled trials (RCTs) that compared subglottic secretion suction versus non-subglottic secretion suction in adults with mechanical ventilation. Meta-analysis was conducted using Revman 5.3, trial sequential analysis (TSA) 0.9 and STATA 12.0. The primary outcome was incidence of VAP. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to evaluate the level of evidence.

Results

Twenty RCTs (N = 3544) were identified. Subglottic secretion suction was associated with reduction of VAP incidence in four high quality trials (relative risk (RR) 0.54, 95 % confidence interval (CI) 0.40–0.74; p < 0.00001) and in all trials (RR = 0.55, 95 % CI 0.48– 0.63; p < 0.00001). Sensitivity analyses did not show differences in the pooled results. Additionally, the results of the above-mentioned analyses were confirmed in TSA. GRADE level was high. Subglottic secretion suction significantly reduced incidence of early onset VAP, gram-positive or gram-negative bacteria causing VAP, and duration of mechanical ventilation. It delayed the time-to-onset of VAP. However, no significant differences in late onset VAP, intensive care unit (ICU) mortality, hospital mortality, or ICU length of stay were found.

Conclusions

Subglottic secretion suction decreased VAP incidence and duration of mechanical ventilation and delayed VAP onset. However, subglottic secretion suction did not reduce mortality and length of ICU stay. Subglottic secretion suction is recommended for preventing VAP and for reducing ventilation length, especially in the population at high risk of early onset VAP.

Trial registration

A protocol of this meta-analysis has been registered on PROSPERO (registration number: CRD42015015715); registered on 5 January 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1527-7) contains supplementary material, which is available to authorized users.

Use of the Blom Tracheotomy Tube with Suction Inner Cannula to Decontaminate Microorganisms from the Subglottic Space. A Proof of Concept

RATIONALE

Preventing pulmonary complications during mechanical ventilation via tracheotomy is a high priority.

OBJECTIVES

To investigate if the Blom tracheotomy tube with suction-above-the-cuff inner cannula reduced the quantity of normal flora and pathogens in supra- versus subglottic spaces.

METHODS

We enrolled 20 consecutive medical ICU adults requiring tracheostomy for mechanical ventilation in this proof-of-concept, prospective, single-center study. All participants received a Blom tracheotomy tube with suction-above-the-cuff inner cannula to decontaminate microorganisms from the supra- and subglottic spaces. Supra- and subglottic sputum samples were obtained for microbiologic analysis while an endotracheal tube was in place before tracheotomy and once per week for up to 4 weeks of mechanical ventilation after tracheotomy.

MEASUREMENTS AND MAIN RESULTS

Demographics, duration of endotracheal tube intubation, and duration of mechanical ventilation post-tracheotomy were recorded. There was a significant reduction for supraglottic (2.86 ± 1.11 [mean ± SD]) versus subglottic suction samples (2.48 ± 1.07) (paired t test, P = 0.048; Wilcoxon test, P = 0.045) when all data pairs for normal flora and pathogens were combined across times. There was a significant reduction of normal flora pooled across times in 19 data pairs for supraglottic (3.00 ± 1.05) versus subglottic suction samples (2.00 ± 0.94) (paired t test, P = 0.0004; Wilcoxon test, P = 0.0007). There was no significant reduction of pathogens pooled across times in 25 data pairs for supraglottic (2.76 ± 1.16) versus subglottic suction samples (2.84 ± 1.03) (paired t test, P = 0.75; Wilcoxon test, P = 0.83).

CONCLUSIONS

Proof-of-concept was confirmed. The Blom tracheotomy tube with disposable suction-above-the-cuff inner cannula decontaminated microorganisms from the subglottic space when normal flora and pathogens were combined. Future research should investigate if decreased quantity of normal flora and pathogens in the subglottic space reduces the incidence of ventilator-associated pulmonary complications in critically ill patients requiring ongoing mechanical ventilation via tracheotomy.

A pilot study of pepsin in tracheal and oral secretions

BACKGROUND

Because reflux of gastric juice into the oropharynx must precede its aspiration into the lungs, it is reasonable to hypothesize that the detection of pepsin (the major gastric enzyme in gastric juice) in oral secretions may provide a relatively noninvasive method of predicting risk for aspiration.

OBJECTIVE

To describe the incidence of pepsin in oral and tracheal secretions collected concurrently from a sample of 50 gastric-fed patients undergoing mechanical ventilation.

METHODS

An exploratory descriptive design with a convenience sample from 4 medical and surgical intensive care units. An oral secretion and a tracheal secretion were collected concurrently from each patient (yielding a sample of 50 oral and 50 tracheal secretions). The tracheal secretions were obtained via the inline suction system with an attached sputum trap; oral secretions were obtained via a Yankauer suction tip with an attached sputum trap. All specimens were assayed for pepsin by the Western blot method.

RESULTS

Oral secretions from 10 patients (20%) and tracheal secretions from 2 patients (4%) were pepsin-positive. Both patients with pepsin-positive tracheal secretions also had pepsin-positive oral secretions. Pepsin was not found in the tracheal secretions from the remaining 8 patients with pepsin-positive oral secretions.

CONCLUSIONS

Although reflux of gastric juice into the oropharynx must precede its aspiration into the lungs, individual reflux events do not necessarily lead to aspiration. Thus, it is reasonable that we found pepsin 5 times more often in oral secretions than in tracheal secretions.

Tracheotomy tubes with suction above the cuff reduce the rate of ventilator-associated pneumonia in intensive care unit patients

OBJECTIVES

We evaluated the effect of tracheotomy tubes that enable suction immediately above the cuff on the development of ventilator-associated pneumonia (VAP).

METHODS

Patients without preexisting pneumonia who required tracheotomy were randomly assigned to receive a tracheotomy tube with or without above-the-cuff suction. The suction tube provided 10 mm Hg of continuous wall suction while the tracheotomy tube cuff was inflated. Data regarding the development of VAP, time on the ventilator, and length of stay in the intensive care unit (ICU) were recorded and compared between groups.

RESULTS

Eighteen patients were randomized and prospectively evaluated. Nine patients received standard tracheotomy tubes, and 9 received suction-above-the-cuff tracheotomy tubes. The prevalences of VAP were 56% in the control group and 11% in the suction tracheotomy group (p = 0.02). The mean times on the ventilator were 18 +/- 14 days in the control group and 11 +/- 11 days in the suction group (p = 0.12). The mean lengths of ICU stay were 26 +/- 15 days in the control group and 18 +/- 15 days in the suction group (p = 0.14).

CONCLUSIONS

Use of suction-above-the-cuff tracheotomy tubes significantly decreases the incidence of VAP in ICU patients. There were trends toward decreased time on the ventilator and decreased length of stay in the ICU.