Continuous control of tracheal cuff pressure for VAP prevention: a collaborative meta-analysis of individual participant data

Continuous cuff pressure control on middle-aged and elderly patients undergoing endoscopic submucosal dissection of the esophagus effect of airway injury

OBJECTIVE

Assessment of the effect of continuous cuff pressure control on airway injury in middle-aged and elderly patients undergoing endoscopic submucosal dissection (ESD).

METHOD

A total of 104 eligible middle-aged and elderly patients requiring esophageal ESD from July 2022-September 2023 at the First Affiliated Hospital of Nanchang University were selected and randomly divided into two groups: the group undergoing general anesthesia tracheal intubation with continuous control of cuff pressure after intubation (Group A, n = 51) and the group undergoing general anesthesia tracheal intubation with continuous monitoring without control of cuff pressure (Group B, n = 53). After endotracheal intubation in Group A, under the guidance of an automatic cuff pressure controller, the air was used to inflate the tracheal cuff until the cuff pressure was 25-30cmH2O. The cuff pressure after intubation was recorded, and then the cuff pressure parameters were directly adjusted in the range of 25-30cmH2O until tracheal extubation after the operation. After endotracheal intubation, patients in Group B inflated the tracheal cuff with clinical experience, then monitored and recorded the cuff pressure with a handheld cuff manometer and instructed the cuff not to be loosened after being connected to the handheld cuff manometer-continuous monitoring until the tracheal extubation, but without any cuff pressure regulation. The patients of the two groups performed esophageal ESD. The left recumbent position was taken before the operation, and the cuff's pressure was recorded. Then, insert the gastrointestinal endoscope to find the lesion site and perform appropriate CO2 inflation to display the diseased esophageal wall for surgical operation fully. After determining the location, the cuff pressure of the two groups was recorded when the cuff pressure was stable. After the operation, the upper gastrointestinal endoscope was removed and the cuff pressure of the two groups was recorded. Postoperative airway injury assessment was performed in both groups, and the incidence of sore throat, hoarseness, cough, and blood in sputum was recorded. The incidence of postoperative airway mucosal injury was also observed and recorded in both groups: typical, episodic congestion spots and patchy local congestion.

RESULT

The incidence of normal airway mucosa in Group A was higher than that in Group B (P < 0.05). In comparison, the incidence of occasional hyperemia and local plaque congestion in Group A was lower than in Group B (P < 0.05).

CONCLUSION

Continuous cuff pressure control during operation can reduce airway injury in patients with esophageal ESD and accelerate their early recovery after the operation.

Continuous Versus Intermittent Control Cuff Pressure for Preventing Ventilator-Associated Pneumonia: An Updated Meta-Analysis

OBJECTIVE

This study aimed to evaluate the effect of continuous control cuff pressure (CCCP) versus intermittent control cuff pressure (ICCP) for the prevention of ventilator-associated pneumonia (VAP) in critically ill patients.

METHODS

Relevant literature was searched in several databases, including PubMed, Embase, Web of Science, ProQuest, the Cochrane Library, Wanfang Database and China National Knowledge Infrastructure between inception and September 2022. Randomized controlled trials were considered eligible if they compared CCCP with ICCP for the prevention of VAP in critically ill patients. This meta-analysis was performed using the RevMan 5.3 and Trial Sequential Analysis 0.9 software packages. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework was used to assess the level of evidence.

RESULTS

We identified 14 randomized control trials with a total of 2080 patients. Meta-analysis revealed that CCCP was associated with a significantly lower incidence of VAP compared with ICCP (relative risk [RR] = 0.52; 95% confidence interval [CI]: 0.37-0.74; P < 0.001), although considerable heterogeneity was observed (I2 = 71%). Conducting trial sequential analysis confirmed the finding, and the GRADE level was moderate. Subgroup analysis demonstrated that CCCP combined with subglottic secretion drainage (SSD) had a more significant effect on reducing VAP (RR = 0.39; 95% CI = 0.29-0.52; P < 0.001). The effect of CCCP on ventilator-associated respiratory infection (VARI) incidence was uncertain (RR = 0.81; 95% CI = 0.53-1.24; P = 0.34; I2 = 61%). Additionally, CCCP significantly reduced the duration of mechanical ventilation (MV) (mean difference [MD] = -2.42 days; 95% CI = -4.71-0.12; P = 0.04; I2 = 87%). Descriptive analysis showed that CCCP improved the qualified rate of cuff pressure. However, no significant differences were found in the length of intensive care unit (ICU) stay (MD = 2.42 days; 95% CI = -1.84-6.68; P = 0.27) and ICU mortality (RR = 0.86; 95% CI = 0.74-1.00; P = 0.05).

CONCLUSION

Our findings suggest that the combination of CCCP and SSD can reduce the incidence of VAP and the duration of MV and maintain the stability of cuff pressure. A combination of CCCP and SSD applications is suggested for preventing VAP.

Ventilator-Associated Pneumonia, Ventilator-Associated Events, and Nosocomial Respiratory Viral Infections on the Leeside of the Pandemic

The COVID-19 pandemic has had an unprecedented impact on population health and hospital operations. Over 7 million patients have been hospitalized for COVID-19 thus far in the United States alone. Mortality rates for hospitalized patients during the first wave of the pandemic were > 30%, but as we enter the fifth year of the pandemic hospitalizations have fallen and mortality rates for hospitalized patients with COVID-19 have plummeted to 5% or less. These gains reflect lessons learned about how to optimize respiratory support for different kinds of patients, targeted use of therapeutics for patients with different manifestations of COVID-19 including immunosuppressants and antivirals as appropriate, and high levels of population immunity acquired through vaccines and natural infections. At the same time, the pandemic has helped highlight some longstanding sources of harm for hospitalized patients including hospital-acquired pneumonia, ventilator-associated events (VAEs), and hospital-acquired respiratory viral infections. We are, thankfully, on the leeside of the pandemic at present; but the large increases in ventilator-associated pneumonia (VAP), VAEs, bacterial superinfections, and nosocomial respiratory viral infections associated with the pandemic beg the question of how best to prevent these complications moving forward. This paper reviews the burden of hospitalization for COVID-19, the intersection between COVID-19 and both VAP and VAEs, the frequency and impact of hospital-acquired respiratory viral infections, new recommendations on how best to prevent VAP and VAEs, and current insights into effective strategies to prevent nosocomial spread of respiratory viruses.

Executive Summary of the Spanish Society of Anesthesiology, Reanimation and Pain Therapy (SEDAR) Spanish Society of Emergency and Emergency Medicine (SEMES) and Spanish Society of Otolaryngology, Head and Neck Surgery (SEORL-CCC) Guideline for difficult airway management

The Airway section of the Spanish Society of Anesthesiology, Reanimation and Pain Therapy (SEDAR), Spanish Society of Emergency and Emergency Medicine (SEMES) and Spanish Society of Otolaryngology, Head and Neck Surgery (SEORL-CCC) present the Guidelines for the integral management of difficult airway in adult patients. This document provides recommendations based on current scientific evidence, theoretical-educational tools and implementation tools, mainly cognitive aids, applicable to the treatment of the airway in the field of anesthesiology, critical care, emergencies and prehospital medicine. Its principles are focused on the human factors, cognitive processes for decision-making in critical situations and optimization in the progression of the application of strategies to preserve adequate alveolar oxygenation in order to improve safety and quality of care.

Spanish Society of Anesthesiology, Reanimation and Pain Therapy (SEDAR), Spanish Society of Emergency and Emergency Medicine (SEMES) and Spanish Society of Otolaryngology, Head and Neck Surgery (SEORL-CCC) Guideline for difficult airway management. Part II

The Airway Management section of the Spanish Society of Anesthesiology, Resuscitation, and Pain Therapy (SEDAR), the Spanish Society of Emergency Medicine (SEMES), and the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC) present the Guide for the comprehensive management of difficult airway in adult patients. Its principles are focused on the human factors, cognitive processes for decision-making in critical situations, and optimization in the progression of strategies application to preserve adequate alveolar oxygenation in order to enhance safety and the quality of care. The document provides evidence-based recommendations, theoretical-educational tools, and implementation tools, mainly cognitive aids, applicable to airway management in the fields of anesthesiology, critical care, emergencies, and prehospital medicine. For this purpose, an extensive literature search was conducted following PRISMA-R guidelines and was analyzed using the GRADE methodology. Recommendations were formulated according to the GRADE methodology. Recommendations for sections with low-quality evidence were based on expert opinion through consensus reached via a Delphi questionnaire.

Is Zero Ventilator-Associated Pneumonia Achievable? Updated Practical Approaches to Ventilator-Associated Pneumonia Prevention

Ventilator-associated pneumonia (VAP) remains a significant clinical entity with reported incidence rates of 7% to 15%. Given the considerable adverse consequences associated with this infection, VAP prevention became a core measure required in most US hospitals. Many institutions took pride in implementing effective VAP prevention bundles that combined at least head of bed elevation, hand hygiene, chlorhexidine oral care, and subglottic drainage. Spontaneous breathing and awakening trials have also consistently been shown to shorten the duration of mechanical ventilation and secondarily reduce the occurrence of VAP.

Association Between Daily Average of Mobility Achieved During Physical Therapy Sessions and Hospital-Acquired or Ventilator-Associated Pneumonia among Critically Ill Patients

PURPOSE

Hospital-acquired and ventilator-associated pneumonias (HAP and VAP) are associated with increased morbidity and mortality. Immobility is a risk factor for developing ICU-acquired weakness (ICUAW). Early mobilization is associated with improved physical function, but its association with hospital-acquired (HAP) and ventilator-associated pneumonias (VAP) is unknown. The purpose of this study is to evaluate the association between daily average of highest level of mobility achieved during physical therapy (PT) and incidence of HAP or VAP among critically ill patients.

MATERIALS AND METHODS

In a retrospective cohort study of progressive mobility program participants in the medical ICU, we used a validated method to abstract new diagnoses of HAP and VAP. We captured scores on a mobility scale achieved during each inpatient physical therapy session and used a Bayesian, discrete time-to-event model to evaluate the association between daily average of highest level of mobility achieved and occurrence of HAP or VAP.

RESULTS

The primary outcome of HAP/VAP occurred in 55 (26.8%) of the 205 participants. Each increase in the daily average of highest level of mobility achieved during PT (0-6 mobility scale) exhibited a protective association with occurrence of HAP or VAP (adjusted hazard ratio [HR] 0.61; 95% CI 0.44, 0.85). Age, baseline ambulatory status, Acute Physiology and Chronic Health Evaluation (APACHE) II, and previous day's mechanical ventilation (MV) status were not significantly associated with the occurrence of HAP/VAP.

CONCLUSIONS

Among critically ill patients in a progressive mobility program, a higher daily average of highest level of mobility achieved during PT was associated with a decreased risk of HAP or VAP.

Relationship Between Intra-Abdominal pressure and microaspiration of gastric contents in critically ill mechanically ventilated patients

The relationship between increased intra-abdominal pressure (IAP) and microaspiration of oro-gastric content in mechanically-ventilated patients has not yet been established. Microaspiration is proposed as one of the causes of ventilator-associated pneumonia (VAP). We aimed to investigate whether mechanically-ventilated patients with increased IAP present evidence of lung microaspiration by assessing pepsin levels in bronchial secretions and evaluated the relationship between pepsin and VAP. 68 mechanically-ventilated patients and 10 control subjects were recruited from an academic ICU in Greece. IAP, pH, pepsin and total protein levels, in bronchial secretions, were assessed within 14 days. Patients underwent assessment for timely VAP diagnosis based on clinical, radiological and laboratory criteria. Pepsin and total protein levels were significantly elevated in patients compared to controls. Pepsin values correlated significantly with IAP (r = 0.61, ***p < 0.001). Multivariate regression analysis showed that IAP was an independent risk factor for increased pepsin values in bronchial secretions [OR95%CI 1.463(1.061-1.620), *p = 0.014]. Pepsin values were higher in patients with VAP, while IAP was independently associated with VAP. There was an indication towards increased VAP in patients with increased pepsin. In conclusion, our results show that pepsin in bronchial secretions may be elevated when IAP is increased, indicating microaspiration and potentially VAP.

In critically ill patients, anti-anaerobic antibiotics increase risk of adverse clinical outcomes

BACKGROUND

Critically ill patients routinely receive antibiotics with activity against anaerobic gut bacteria. However, in other disease states and animal models, gut anaerobes are protective against pneumonia, organ failure and mortality. We therefore designed a translational series of analyses and experiments to determine the effects of anti-anaerobic antibiotics on the risk of adverse clinical outcomes among critically ill patients.

METHODS

We conducted a retrospective single-centre cohort study of 3032 critically ill patients, comparing patients who did and did not receive early anti-anaerobic antibiotics. We compared intensive care unit outcomes (ventilator-associated pneumonia (VAP)-free survival, infection-free survival and overall survival) in all patients and changes in gut microbiota in a subcohort of 116 patients. In murine models, we studied the effects of anaerobe depletion in infectious (Klebsiella pneumoniae and Staphylococcus aureus pneumonia) and noninfectious (hyperoxia) injury models.

RESULTS

Early administration of anti-anaerobic antibiotics was associated with decreased VAP-free survival (hazard ratio (HR) 1.24, 95% CI 1.06-1.45), infection-free survival (HR 1.22, 95% CI 1.09-1.38) and overall survival (HR 1.14, 95% CI 1.02-1.28). Patients who received anti-anaerobic antibiotics had decreased initial gut bacterial density (p=0.00038), increased microbiome expansion during hospitalisation (p=0.011) and domination by Enterobacteriaceae spp. (p=0.045). Enterobacteriaceae were also enriched among respiratory pathogens in anti-anaerobic-treated patients (p<2.2×10^-16). In murine models, treatment with anti-anaerobic antibiotics increased susceptibility to Enterobacteriaceae pneumonia (p<0.05) and increased the lethality of hyperoxia (p=0.0002).

CONCLUSIONS

In critically ill patients, early treatment with anti-anaerobic antibiotics is associated with increased mortality. Mechanisms may include enrichment of the gut with respiratory pathogens, but increased mortality is incompletely explained by infections alone. Given consistent clinical and experimental evidence of harm, the widespread use of anti-anaerobic antibiotics should be reconsidered.

Effectiveness of Continuous Cuff Pressure Control in Preventing Ventilator-Associated Pneumonia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVES

Microaspiration of subglottic secretions is the main pathogenic mechanism for ventilator-associated pneumonia (VAP). Adequate inflation of the endotracheal cuff is pivotal to providing an optimal seal of the extraluminal airway. However, cuff pressure substantially fluctuates due to patient or tube movements, which can induce microaspiration. Therefore, devices for continuous cuff pressure control (CCPC) have been developed in recent years. The purpose of this systematic review and meta-analysis is to assess the effectiveness of CCPC in VAP prevention.

DATA SOURCES

A systematic search of Embase, the Cochrane Central Register of Controlled Trials, and the International Clinical Trials Registry Platform was conducted up to February 2022.

STUDY SELECTION

Eligible studies were randomized controlled trials (RCTs) and quasi-RCTs comparing the impact of CCPC versus intermittent cuff pressure control on the occurrence of VAP.

DATA EXTRACTION

Random-effects meta-analysis was used to calculate odds ratio (OR) and 95% CI for VAP incidence between groups. Secondary outcome measures included mortality and duration of mechanical ventilation (MV) and ICU stay. The certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach.

DATA SYNTHESIS

Eleven RCTs with 2,092 adult intubated patients were included. The use of CCPC was associated with a reduced risk of VAP (OR, 0.51). Meta-analyses of secondary endpoints showed no significant difference in mortality but significant differences in durations of MV (mean difference, -1.07 d) and ICU stay (mean difference, -3.41 d) in favor of CCPC. However, the risk of both reporting and individual study bias was considered important. The main issues were the lack of blinding, potential commercial conflicts of interest of study authors and high heterogeneity due to methodological differences between studies, differences in devices used for CCPC and in applied baseline preventive measures. Certainty of the evidence was considered "very low."

CONCLUSIONS

The use of CCPC was associated with a reduction in VAP incidence; however, this was based on very low certainty of evidence due to concerns related to risk of bias and inconsistency.

Nosocomial Pneumonia in the Mechanically Ventilated Patient

Ventilator-associated pneumonia (VAP) is a common complication occurring in critically ill patients who are mechanically ventilated and is the leading cause of nosocomial infection-related death. Etiologic agents for VAP widely differ based on the population of intensive care unit patients, duration of hospital stay, and prior antimicrobial therapy. VAP due to multidrug-resistant pathogens is associated with the highest morbidity and mortality, likely due to delays in appropriate antimicrobial treatment. International guidelines are currently available to guide diagnostic and therapeutic strategies. VAP can be prevented through various pharmacological and non-pharmacological interventions, which are more effective when grouped as bundles. When VAP is clinically suspected, diagnostic strategies should include early collection of respiratory samples to guide antimicrobial therapy. Empirical treatment should be based on the most likely etiologic microorganisms and antibiotics likely to be active against these microorganisms. Response to therapy should be reassessed after 3 to 5 days and antimicrobials adjusted or de-escalated to reduce the burden of the disease. Finally, considering that drug resistance is increasing worldwide, several novel antibiotics are being tested to efficiently treat VAP in the coming decades.

Complications associated with long-term positive-pressure ventilation in dogs and cats: 67 cases

OBJECTIVES

To determine the complications associated with positive-pressure ventilation (PPV) in dogs and cats.

DESIGN

Retrospective study from October 2009 to September 2013.

SETTING

University Teaching Hospital.

ANIMALS

Fifty-eight dogs and 9 cats.

MEASUREMENTS AND MAIN RESULTS

Medical records were retrospectively reviewed; signalment, complications associated with PPV, duration of PPV, and outcome were recorded. Complications most commonly recorded during PPV included hypothermia 41/67 (61%), hypotension 39/67 (58%), cardiac arrhythmias 33/67 (49%), a positive fluid balance 31/67 (46%), oral lesions 25/67 (37%), and corneal ulcerations 24/67 (36%). A definition of ventilator-associated events (VAE) extrapolated from the Center of Disease Control's criteria was applied to 21 cases that received PPV for at least 4 days in this study. Ventilator-associated conditions occurred in 5 of 21 (24%) of cases with infection-related ventilator-associated conditions and ventilator-associated pneumonia identified in 3 of 21 (14%) cases.

CONCLUSIONS

Complications are common and diverse in dogs and cats receiving long-term PPV and emphasizes the importance of intensive, continuous patient monitoring and appropriate nursing care protocols. Many of the complications identified could be serious without intervention and suggests that appropriate equipment alarms could improve patient safety. Development of veterinary specific surveillance tools such as the VAE criteria would aid future investigations and allow for effective multicenter studies.

Automatic Continuous Control of Cuff Pressure and Subglottic Secretion Suction Used Together to Prevent Pneumonia in Ventilated Patients-A Retrospective and Prospective Cohort Study

The ventilator bundle consists of multiple methods to reduce ventilator-associated pneumonia (VAP) rates in Intensive Care Units (ICU). The aim of the study was to evaluate how the continuous automatic pressure control in tapered cuffs of endotracheal/tracheostomy tubes applied along with continuous automatic subglottic secretion suction affect the incidence of VAP. In the prospective cohort (n = 198), the standard VAP bundle was modified by continuous automatic pressure control in taper-shaped cuff of endotracheal/tracheostomy tubes and subglottic secretion suction. VAP incidence, time to VAP onset, invasive mechanical ventilation days/free days, length of ICU stay, ICU mortality, and multidrug-resistant bacteria were assessed and compared to the retrospective cohort (n = 173) with the standard bundle (intermittent cuff pressure of standard cuff, lack of subglottic secretion suction). A smaller incidence of VAP (9.6% vs. 19.1%) and early onset VAP (1.5% vs. 8.1%) was found in the prospective compared to the retrospective cohort (p < 0.01). Patients in the prospective cohort were less likely to develop VAP (RR = 0.50; 95% CI: 0.29 to 0.85) and early-onset VAP (RR = 0.19; 95% CI: 0.05 to 0.64) and had longer time to onset VAP (median 9 vs. 5 days; p = 0.03). There was no significant difference (p > 0.05) between both cohorts in terms of invasive mechanical ventilation days/free days, length of ICU stay, ICU mortality and multidrug-resistant bacteria. Modification of the bundle for prevention of VAP can reduce early-onset VAP and total incidence of VAP and delay the time of VAP occurrence.

Effects of Head and Neck Position on Nasotracheal Tube Intracuff Pressure: A Prospective Observational Study

To prevent endotracheal tube-related barotrauma or leakage, the intracuff pressure should be adjusted to 20-30 cm H₂O. However, changes in the nasotracheal tube intracuff pressure relative to neck posture are unclear. In this study, we investigated the effect of head and neck positioning on nasotracheal tube intracuff pressure. Fifty adult patients with nasotracheal tubes who were scheduled for surgery under general anesthesia were enrolled. Following intubation, intracuff pressure was measured by connecting the pilot balloon to a device that continuously monitors the intracuff pressure. Subsequently, the intracuff pressure was set to 24.48 cm H₂O (=18 mmHg) for the neutral position. We recorded the intracuff pressures based on the patients' position during head flexion, extension, and rotation. The initial intracuff pressure was 42.2 cm H₂O [29.6-73.1] in the neutral position. After pressure adjustment in the neutral position, the intracuff pressure was significantly different from the neutral to flexed (p < 0.001), extended (p = 0.003), or rotated (p < 0.001) positions. Although the median change in intracuff pressure was <3 cm H₂O when each patient's position was changed, overinflation to >30 cm H₂O occurred in 12% of patients. Therefore, it is necessary to adjust the intracuff pressure after tracheal intubation and each positional change.

Effectiveness of continuous endotracheal cuff pressure control for the prevention of ventilator associated respiratory infections: an open-label randomised, controlled trial

Background

An endotracheal tube cuff pressure between 20 and 30 cmH₂O is recommended to prevent ventilator-associated respiratory infection (VARI). We aimed to evaluate whether continuous cuff pressure control (CPC) was associated with reduced VARI incidence compared with intermittent CPC.

Methods

We conducted a multicenter open-label randomized controlled trial in intensive care unit (ICU) patients within 24 hours of intubation in Vietnam. Patients were randomly assigned 1:1 to receive either continuous CPC using an automated electronic device or intermittent CPC using a manually hand-held manometer. The primary endpoint was the occurrence of VARI, evaluated by an independent reviewer blinded to the CPC allocation.

Results

We randomized 600 patients; 597 received the intervention or control and were included in the intention to treat analysis. Compared with intermittent CPC, continuous CPC did not reduce the proportion of patients with at least one episode of VARI (74/296 [25%] vs 69/301 [23%]; odds ratio [OR] 1.13; 95% confidence interval [CI] .77–1.67]. There were no significant differences between continuous and intermittent CPC concerning the proportion of microbiologically confirmed VARI (OR 1.40; 95% CI .94–2.10), the proportion of intubated days without antimicrobials (relative proportion [RP] 0.99; 95% CI .87–1.12), rate of ICU discharge (cause-specific hazard ratio [HR] 0.95; 95% CI .78–1.16), cost of ICU stay (difference in transformed mean [DTM] 0.02; 95% CI −.05 to .08], cost of ICU antimicrobials (DTM 0.02; 95% CI −.25 to .28), cost of hospital stay (DTM 0.02; 95% CI −.04 to .08), and ICU mortality risk (OR 0.96; 95% CI .67–1.38).

Conclusions

Maintaining CPC through an automated electronic device did not reduce VARI incidence.

Clinical Trial Registration

NCT02966392.

Rapid-flow expulsion maneuver in subglottic secretion clearance to prevent ventilator-associated pneumonia: a randomized controlled study

Background

Following endotracheal intubation, clearing secretions above the endotracheal tube cuff decreases the incidence of ventilator-associated pneumonia (VAP); therefore, subglottic secretion drainage (SSD) is widely advocated. Our group developed a novel technique to remove the subglottic secretions, the rapid-flow expulsion maneuver (RFEM). The objective of this study was to explore the effectiveness and safety of RFEM compared with SSD.

Methods

This study was a single-center, prospective, randomized and controlled trial, conducted at Respiratory Intensive Care Unit (ICU) of Beijing Chao-Yang Hospital, a university-affiliated tertiary hospital. The primary outcome was the incidence of VAP, assessed for non-inferiority.

Results

Patients with an endotracheal tube allowing drainage of subglottic secretions (n = 241) were randomly assigned to either the RFEM group (n = 120) or SSD group (n = 121). Eleven patients (9.17%) in the RFEM group and 13 (10.74%) in the SSD group developed VAP (difference, − 1.59; 95% confidence interval [CI] [− 9.20 6.03]), as the upper limit of 95% CI was not greater than the pre-defined non-inferiority limit (10%), RFEM was declared non-inferior to SSD. There were no statistically significant differences in the duration of mechanical ventilation, ICU mortality, or ICU length of stay and costs between groups. In terms of safety, no accidental extubation or maneuver-related barotrauma occurred in the RFEM group. The incidence of post-extubation laryngeal edema and reintubation was similar in both groups.

Conclusions

RFEM is effective and safe, with non-inferiority compared to SSD in terms of the incidence of VAP. RFEM could be an alternative method in first-line treatment of respiratory ICU patients.

Trial registration This study has been registered on ClinicalTrials.gov (Registration Number: NCT02032849, https://clinicaltrials.gov/ct2/show/NCT02032849); registered on January 2014

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00887-5.

Continuous Pneumatic Regulation of Tracheal Cuff Pressure to Decrease Ventilator-associated Pneumonia in Trauma Patients Who Were Mechanically Ventilated: The AGATE Multicenter Randomized Controlled Study

BACKGROUND

Ventilator-associated pneumonia (VAP) is the most frequent health care-associated infection in severely ill patients, and aspiration of contaminated oropharyngeal content around the cuff of the tracheal tube is the main route of contamination.

RESEARCH QUESTION

Is continuous regulation of tracheal cuff pressure using a pneumatic device superior to manual assessment three times daily using a portable manometer (routine care) in preventing VAP in patients with severe trauma?

STUDY DESIGN AND METHODS

In this open-label, randomized controlled superiority trial conducted in 13 French ICUs, adults (age ≥ 18 years) with severe trauma (Injury Severity Score > 15) and requiring invasive mechanical ventilation for ≥ 48 h were enrolled. Patients were randomly assigned (1:1) via a secure Web-based random number generator in permuted blocks of variable sizes to one of two groups according to the method of tracheal cuff pressure control. The primary outcome was the proportion of patients developing VAP within 28 days following the tracheal intubation, as determined by two assessors masked to group assignment, in the modified intention-to-treat population. This study is closed to new participants.

RESULTS

A total of 434 patients were recruited between July 31, 2015, and February 15, 2018, of whom 216 were assigned to the intervention group and 218 to the control group. Seventy-three patients (33.8%) developed at least one episode of VAP within 28 days following the tracheal intubation in the intervention group compared with 64 patients (29.4%) in the control group (adjusted subdistribution hazard ratio, 0.96; 95% CI, 0.76-1.20; P = .71). No serious adverse events related to the use of the pneumatic device were noted.

INTERPRETATION

Continuous regulation of cuff pressure of the tracheal tube using a pneumatic device was not superior to routine care in preventing VAP in patients with severe trauma.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT02534974; URL: www.clinicaltrials.gov.

Continuous Endotracheal Tube Cuff Pressure Control Decreases Incidence of Ventilator-Associated Pneumonia in Patients with Traumatic Brain Injury

BACKGROUND

Ventilator-associated pneumonia (VAP) is a common cause of morbidity and mortality in intensive care unit (ICU), and among the several preventative strategies described to reduce the incidence of VAP, the most important is the endotracheal tube cuff (ETC) pressure. The present study was conducted on 60 patients who required mechanical ventilation (MV) in the ICU with traumatic brain injury (TBI).

METHODS

The patients were randomized into two groups of 30, in which ETC pressure was regulated using a smart cuff manager (SCM) (Group II), or manual measurement approach (MMA) (Group I). Demographic data, MV duration, length of ICU stay and mortality rates were recorded. The clinical pulmonary infection scores (CPISs), C-reactive protein (CRP) values, and the fraction of inspired oxygen (FiO2) and positive end-expiratory pressure (PEEP) values of the groups were compared at baseline, and at hours 48, 72 and 96.

RESULTS

In Group I, CPIS values significantly higher than Group II in 48th, 72nd and 96th hours (p < 0.05). In Group I, PEEP values and deep tracheal aspirate (DTA) culture growth rates significantly higher than Group II in 72nd and 96th hours (p < 0.05).

CONCLUSION

The continuous maintenance of ETC pressure using SCM reduced the incidence of VAP.

Effects of anesthesiologists awareness on the control of cuff pressure in patients submitted to cardiac surgery

INTRODUCTION

Sedatives applied to cardiac surgery patients can act on the respiratory tract, creating a demand for a tracheal prosthesis in the artificial route, whose distal part (cuff) has a recommended pressure of 20 to 25 mm Hg. The professional's lack of knowledge about procedures and adequate pressure can pose risks to patients' health.

OBJECTIVE

To analyze the effect of anesthesiologists awareness on the control of cuff pressure.

METHODOLOGY

A prospective cohort study. At the beginning of the research, cuff pressures were consecutively measured immediately after the patient's admission to the intensive care unit (ICU). After this period, anesthesiologists were trained by the responsible researchers for 1 month. In the final 2.5 months of the research, cuff pressure was again measured immediately after the patient's admission to the ICU.

RESULTS

A total of 70 patients were evaluated, 37 of whom were pre-awareness and 33 were post-awareness. Male sex was the most prevalent with 46 (66%) patients and the mean age was 58 ± 10 years. There was a reduction from 76 ± 14 to 28 ± 9 in cuff pressure (P < .01).

CONCLUSION

The training of anesthesiologists who assist cardiac surgery patients allowed a reduction in cuff pressure abnormalities.

Ventilator-associated pneumonia in adults: a narrative review

Ventilator-associated pneumonia (VAP) is one of the most frequent ICU-acquired infections. Reported incidences vary widely from 5 to 40% depending on the setting and diagnostic criteria. VAP is associated with prolonged duration of mechanical ventilation and ICU stay. The estimated attributable mortality of VAP is around 10%, with higher mortality rates in surgical ICU patients and in patients with mid-range severity scores at admission. Microbiological confirmation of infection is strongly encouraged. Which sampling method to use is still a matter of controversy. Emerging microbiological tools will likely modify our routine approach to diagnosing and treating VAP in the next future. Prevention of VAP is based on minimizing the exposure to mechanical ventilation and encouraging early liberation. Bundles that combine multiple prevention strategies may improve outcomes, but large randomized trials are needed to confirm this. Treatment should be limited to 7 days in the vast majority of the cases. Patients should be reassessed daily to confirm ongoing suspicion of disease, antibiotics should be narrowed as soon as antibiotic susceptibility results are available, and clinicians should consider stopping antibiotics if cultures are negative.

Tracheal tube cuff pressure monitoring: Assessing current practice in critically ill patients at Chris Hani Baragwanath Academic Hospital

Background

Intubated patients with a high tracheal tube cuff pressure (CP) are at risk of developing tracheal or subglottic stenosis. Recently an increasing number of patients have presented to our hospital with these complications.

Objectives

To determine the frequency of tracheal tube CP measurements and the range of CP and to explore nursing knowledge regarding CP monitoring.

Methods

Frequency of CP measurement was assessed using a prospective chart review, followed by an interventional component. In the final stage nurses completed a self-administered questionnaire.

Results

A total of 304 charts from 61 patients were reviewed. Patients' ages ranged from 1 to 71 years, with a male preponderance (1.5:1). The majority of charts (87%) did not reflect a documented CP measurement and only 12 charts showed at least one measurement per shift. Only 17% of recorded CPs were within the recommended range; 59% were too low. The questionnaire was completed by only 51% of the 75 respondents. Nursing experience ranged from 3 to 35 years and 92% of respondents were trained in critical care. Knowledge of current critical care CP monitoring guidelines was reported by 62% of the respondents (n=23/37). Only 53% (20/38) reported routinely measuring CP. Almost all respondents (94%) knew of at least one complication of abnormal CP.

Conclusion

Having a basic knowledge of CP measurement, having awareness of the complications of abnormal CP and the availability of national best practice guidelines did not translate into appropriate ICU practice. Research into effective implementation strategies to achieve best practice is needed.

Contributions of the study

Basic knowledge of cuff pressure measurement may not always result in best practice.Improvement in current practice requires research into effective implementation strategies.

Prevention of Ventilator-Associated and Early Postoperative Pneumonia Through Tapered Endotracheal Tube Cuffs: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

Microaspiration of subglottic secretions is considered a major pathogenic mechanism of hospital-acquired pneumonia, either early postoperative or ventilator-associated pneumonia. Tapered endotracheal tube cuffs have been proposed to provide a better seal of the extraluminal airway, thereby preventing microaspiration and possibly hospital-acquired pneumonia. We performed a systematic review and meta-analysis to assess the value of endotracheal tubes with tapered cuffs in the prevention of hospital-acquired pneumonia.

DATA SOURCES

A systematic search of MEDLINE, EMBASE, CENTRAL/CCTR, ClinicalTrials.gov, and ICTRP was conducted up to March 2017.

STUDY SELECTION

Eligible trials were randomized controlled clinical trials comparing the impact of tapered cuffs versus standard cuffs on hospital-acquired pneumonia.

DATA EXTRACTION

Random-effects meta-analysis calculated odds ratio and 95% CI for hospital-acquired pneumonia occurrence rate between groups. Secondary outcome measures included mortality, duration of mechanical ventilation, length of hospital and ICU stay, and cuff underinflation.

DATA SYNTHESIS

Six randomized controlled clinical trials with 1,324 patients from intensive care and postoperative wards were included. Only two studies concomitantly applied subglottic secretion drainage, and no trial performed continuous cuff pressure monitoring. No significant difference in hospital-acquired pneumonia incidence per patient was found when tapered cuffs were compared with standard cuffs (odds ratio, 0.97; 95% CI, [0.73-1.28]; p = 0.81). There were likewise no differences in secondary outcomes.

CONCLUSIONS

Application of tapered endotracheal tube cuffs did not reduce hospital-acquired pneumonia incidence among ICU and postoperative patients. Further research should examine the impact of concomitant use of tapered cuffs with continuous cuff pressure monitoring and subglottic secretion drainage.

Airway Devices in Ventilator-Associated Pneumonia Pathogenesis and Prevention

Airway devices play a major role in the pathogenesis of microaspiration of contaminated oropharyngeal and gastric secretions, tracheobronchial colonization, and ventilator-associated pneumonia (VAP) occurrence. Subglottic secretion drainage is an effective measure for VAP prevention, and no routine change of ventilator circuit. Continuous control of cuff pressure, silver-coated tracheal tubes, low-volume low-pressure tracheal tubes, and the mucus shaver are promising devices that should be further evaluated by large randomized controlled trials. Polyurethane-cuffed, conical-shaped cuff, and closed tracheal suctioning system are not effective and should not be used for VAP prevention.

Is Zero Ventilator-Associated Pneumonia Achievable?: Practical Approaches to Ventilator-Associated Pneumonia Prevention

Ventilator-associated pneumonia (VAP) remains a significant clinical entity with reported incidence rates of 7% to 15%. Given the considerable adverse consequences associated with this infection, VAP prevention became a core measure required in most US hospitals. Many institutions implemented effective VAP prevention bundles that combined head of bed elevation, hand hygiene, chlorhexidine oral care, and subglottic drainage. More recently, spontaneous breathing and awakening trials have consistently been shown to shorten the duration of mechanical ventilation and secondarily reduce the occurrence of VAP. More recent data question the overall positive impact of prevention bundles, including some of their core component interventions.

An in-vitro study to evaluate high-volume low-pressure endotracheal tube cuff deflation dynamics

BACKGROUND

High-volume low-pressure (HVLP) endotracheal tube (ETT) cuffs for critically ill patients often deflate during the course of mechanical ventilation. We performed an in-vitro study to comprehensively assess HVLP cuff deflation dynamics and potential preventive measures.

METHODS

We evaluated 24-hour deflation of seven HVLP cuffs of cylindrical or tapered shape, and made of polyvinylchloride or polyurethane. Experiments were performed within a thermostated chamber set at 37 °C. In the first stage of experiments, the cuff pilot balloon valve was not manipulated. The cuff internal pressure was assessed hourly for 24 hours, via a linear position sensor which monitored cuff deflation displacements. Then, we re-evaluated cuff deflation of the worst-performing ETT cuffs with the cuff pilot balloon valve sealed. Finally, we inflated ETT cuffs within an artificial trachea to evaluate deflation dynamics during mechanical ventilation.

RESULTS

Initial tests showed an exponential decrease in cuff internal pressure in five out of seven cuffs. Cuffs of cylindrical shape and made of polyurethane demonstrated the fastest deflation rates (P<0.050 vs. cuffs of conical shape and made of polyvinylchloride). When the cuff pilot balloon valve was not sealed, the internal cuff pressure deflation rate differed significantly among ETTs (P=0.005). Yet, upon sealing the cuff pilot balloon valve and during mechanical ventilation, cuff deflation rates decreased (P<0.050).

CONCLUSIONS

In controlled in-vitro settings, ETT cuffs consistently deflate over time, and the cuff pilot balloon valve plays a central role in this occurrence. Deflation rate decreases when cuffs are inflated within a plastic artificial tracheal model and mechanical ventilation is activated.

Is continuous better than intermittent control of tracheal cuff pressure? A meta-analysis

AIM

To compare and evaluate the efficacy and safety of continuous and intermittent control of cuff pressure.

METHODS

We performed a comprehensive and systematic meta-analysis of randomized controlled trials (RCTs) assessing the continuous and intermittent control of P_cuff by searching PUBMED, EMBASE and other such databases (from inception to 31 March 2018). Summary odds ratios or mean differences with 95% confidence intervals were calculated using a fixed- or random-effects model.

MEASUREMENTS AND MAIN RESULTS

Seven randomised controlled trials with 970 mechanically ventilated patients were included in this study. The continuous control of cuff pressure significantly reduced the incidence of cuff pressure < 20 cm H₂ O (0.03 (OR) (95% CI: 0.01-0.07)), P_cuff > 30 cm H₂ O (0.06 (95% CI: 0.03-0.15)) and VAP (0.39 (95% CI: 0.28-0.55)) when compared with intermittent control of cuff pressure. No significant differences in duration of MV (-1.94 (95% CI: -4.06 to -0.17)), length of ICU stay (-3.88 (95% CI: -9.00 to -1.23)) and mortality (0.99 (95% CI: 0.73-1.35)) were found between the two groups.

CONCLUSIONS

Continuous control of cuff pressure offers more benefits in stabilizing the cuff pressure and reducing the incidence of VAP, and more studies are warranted to further evaluate the role of continuous control of cuff pressure.

RELEVANCE TO PRACTICE

The continuous control of cuff pressure should be conducted whenever possible as it is the most ideal for the prognosis of MV patients.

Unintentional endotracheal tube cuff deflation during routine checks: a simulation study

BACKGROUND

Endotracheal tube cuff pressures should be maintained between 20 and 30 cm H₂ O to prevent the aspiration of subglottic secretions past the cuff. Guidance recommends regular monitoring of the cuff pressure, performed using a handheld manometer/inflator. Poor technique can lead to transient deflation of the cuff, leading to the bolus aspiration of upper respiratory tract secretions, tracheal colonization and, ultimately, ventilator-associated pneumonia.

AIMS AND OBJECTIVES

To determine whether intensive care staff transiently deflate the endotracheal tube cuff to below 20 cm H₂ O during routine cuff pressure checks when using a handheld manometer/inflator device.

DESIGN

This was an exploratory simulation study.

METHODS

A sample of medical (n = 10) and nursing staff (n = 10), capable of caring for a tracheally intubated patient, participated in the study on a single day. A mannequin was intubated with a standard oral endotracheal tube with the cuff pressure set at 50 cm H₂ O. Participants were required to check and correct the cuff pressure to the appropriate level with a manometer. The lowest attained and the final target pressures were recorded.

RESULTS

Three doctors were unfamiliar with the manometer and did not attempt measurement. During cuff pressure readjustment, 59% (10/17) of participants transiently deflated the cuff below 20 cm H₂ O and then re-inflated to attain the final pressure. Of these participants, four deflated the cuff pressure to 0 cm H₂ O before re-adjusting it back into range. Most participants, 88% (15/17), corrected the final cuff pressure to between 20 and 30 cm H₂ O.

CONCLUSIONS

Poor technique when using the manometer led to unintentional cuff deflation during routine checks. In clinical practice, this could increase the risk of pulmonary aspiration and ventilator-associated pneumonia. Further research into alternatives for handheld manometers, such as automated continuous cuff pressure monitors, is warranted.

RELEVANCE TO CLINICAL PRACTICE

Cuff deflations can easily occur during routine cuff pressure checks. Staff should be aware of the implications of cuff deflations and seek to improve training with manometers.

Effects of chlorhexidine gluconate oral care on hospital mortality: a hospital-wide, observational cohort study

Purpose

Chlorhexidine oral care is widely used in critically and non-critically ill hospitalized patients to maintain oral health. We investigated the effect of chlorhexidine oral care on mortality in a general hospitalized population.

Methods

In this single-center, retrospective, hospital-wide, observational cohort study we included adult hospitalized patients (2012–2014). Mortality associated with chlorhexidine oral care was assessed by logistic regression analysis. A threshold cumulative dose of 300 mg served as a dichotomic proxy for chlorhexidine exposure. We adjusted for demographics, diagnostic category, and risk of mortality expressed in four categories (minor, moderate, major, and extreme).

Results

The study cohort included 82,274 patients of which 11,133 (14%) received chlorhexidine oral care. Low-level exposure to chlorhexidine oral care (≤ 300 mg) was associated with increased risk of death [odds ratio (OR) 2.61; 95% confidence interval (CI) 2.32–2.92]. This association was stronger among patients with a lower risk of death: OR 5.50 (95% CI 4.51–6.71) with minor/moderate risk, OR 2.33 (95% CI 1.96–2.78) with a major risk, and a not significant OR 1.13 (95% CI 0.90–1.41) with an extreme risk of mortality. Similar observations were made for high-level exposure (> 300 mg). No harmful effect was observed in ventilated and non-ventilated ICU patients. Increased risk of death was observed in patients who did not receive mechanical ventilation and were not admitted to ICUs. The adjusted number of patients needed to be exposed to result in one additional fatality case was 47.1 (95% CI 45.2–49.1).

Conclusions

These data argue against the indiscriminate widespread use of chlorhexidine oral care in hospitalized patients, in the absence of proven benefit in specific populations.

Electronic supplementary material

The online version of this article (10.1007/s00134-018-5171-3) contains supplementary material, which is available to authorized users.

Multicentre randomised controlled trial to investigate the usefulness of continuous pneumatic regulation of tracheal cuff pressure for reducing ventilator-associated pneumonia in mechanically ventilated severe trauma patients: the AGATE study protocol

INTRODUCTION

Severe trauma represents the leading cause of mortality worldwide. While 80% of deaths occur within the first 24 hours after trauma, 20% occur later and are mainly due to healthcare-associated infections, including ventilator-associated pneumonia (VAP). Preventing underinflation of the tracheal cuff is recommended to reduce microaspiration, which plays a major role in the pathogenesis of VAP. Automatic devices facilitate the regulation of tracheal cuff pressure, and their implementation has the potential to reduce VAP. The objective of this work is to determine whether continuous regulation of tracheal cuff pressure using a pneumatic device reduces the incidence of VAP compared with intermittent control in severe trauma patients.

METHODS AND ANALYSIS

This multicentre randomised controlled and open-label trial will include patients suffering from severe trauma who are admitted within the first 24 hours, who require invasive mechanical ventilation to longer than 48 hours. Their tracheal cuff pressure will be monitored either once every 8 hours (control group) or continuously using a pneumatic device (intervention group). The primary end point is the proportion of patients that develop VAP in the intensive care unit (ICU) at day 28. The secondary end points include the proportion of patients that develop VAP in the ICU, early (≤7 days) or late (>7 days) VAP, time until the first VAP diagnosis, the number of ventilator-free days and antibiotic-free days, the length of stay in the ICU, the proportion of patients with ventilator-associated events and that die during their ICU stay.

ETHICS AND DISSEMINATION

This protocol has been approved by the ethics committee of Poitiers University Hospital, and will be carried out according to the principles of the Declaration of Helsinki and the Good Clinical Practice guidelines. The results of this study will be disseminated through presentation at scientific conferences and publication in peer-reviewed journals.

TRIAL REGISTRATION

Clinical Trials NCT02534974.

CO2 driven endotracheal tube cuff control in critically ill patients: A randomized controlled study

Background

To determine the safety and clinical efficacy of an innovative integrated airway system (AnapnoGuard^™ 100 system) that continuously monitors and controls the cuff pressure (P_cuff), while facilitating the aspiration of subglottic secretions (SS).

Methods

This was a prospective, single centre, open-label, randomized, controlled feasibility and safety trial. The primary endpoint of the study was the rate of device related adverse events (AE) and serious AE (SAE) as a result of using AnapnoGuard (AG) 100 during mechanical ventilation. Secondary endpoints were: (1) mechanical complications rate (2) ICU staff satisfaction; (3) VAP occurrence; (4) length of mechanical ventilation; (5) length of Intensive Care Unit stay and mortality; (6) volume of evacuated subglottic secretions.

Sixty patients were randomized to be intubated with the AG endotracheal-tube (ETT) and connected to the AG 100 system allowing P_cuff adjustment and SS aspiration; or with an ETT combined with SS drainage and P_cuff controlled manually.

Results

No difference in adverse events rate was identified between the groups. The use of AG system was associated with a significantly higher incidence of P_cuff determinations in the safety range (97.3% vs. 71%; p<0.01) and a trend to a greater volume of aspirated SS secretions: (192.0[64–413] ml vs. 150[50–200], p = 0.19 (total)); (57.8[20–88.7] ml vs. 50[18.7–62] ml, p = 0.11 (daily)). No inter-group difference was detected using AG system vs. controls in terms of post-extubation throat pain level (0 [0–2] vs. 0 [0–3]; p = 0.7), hoarseness (42.9% vs. 75%; p = 0.55) and tracheal mucosa oedema (16.7% vs. 10%; p = 0.65).

Patients enrolled in the AG group had a trend to reduced VAP risk of ventilator-associated pneumonia(VAP) (14.8% vs. 40%; p = 0.06), which were more frequently monomicrobial (25% vs. 70%; p = 0.03).

No statistically significant difference was observed in duration of mechanical ventilation, ICU stay, and mortality.

Conclusions

The use AG 100 system and AG tube in critically ill intubated patients is safe and effective in P_cuff control and SS drainage. Its protective role against VAP needs to be confirmed in a larger randomized trial.

Trial registration

ClinicalTrials.gov NCT01550978. Date of registration: February 21, 2012.

Impact of tapered-cuff tracheal tube on microaspiration of gastric contents in intubated critically ill patients: a multicenter cluster-randomized cross-over controlled trial

PURPOSE

Studies on the impact of tapered-cuff tracheal tubes on rates of microaspiration and ventilator-associated pneumonia (VAP) in intubated patients have reported conflicting results. The aim of this study was to determine the influence of this shape of tracheal cuff on abundant microaspiration of gastric contents in critically ill patients.

METHODS

All patients intubated in the intensive care unit (ICU) and requiring mechanical ventilation for at least 48 h were eligible for this multicenter cluster-randomized controlled cross-over open-label study. The primary outcome was abundant microaspiration of gastric contents, defined by the presence of pepsin at significant level in >30% of tracheal aspirates. Quantitative measurement of pepsin and salivary amylase was performed in all tracheal aspirates during the 48 h following enrollment.

RESULTS

A total of 326 patients were enrolled in the ten participating ICUs (162 in the PVC tapered-cuff group and 164 in the standard-cuff group). Patient characteristics were similar in the two study groups. The proportion of patients with abundant microaspiration of gastric contents was 53.5% in the tapered-cuff and 51.0% in the standard-cuff group (odds ratio 1.14, 95% CI 0.72-1.82). While abundant microaspiration of oropharyngeal secretions was not significantly different (77.4 vs 68.6%, p = 0.095), the proportion of patients with tracheobronchial colonization was significantly lower (29.6 vs 43.3%, p = 0.01) in the tapered-cuff than in the standard-cuff group. No significant difference between the two groups was found for other secondary outcomes, including ventilator-associated events and VAP.

CONCLUSIONS

This trial showed no significant impact of tapered-cuff tracheal tubes on abundant microaspiration of gastric contents.

TRIAL REGISTRATION

ClinicalTrials.gov, number NCT01948635.

Efficiency of an electronic device in controlling tracheal cuff pressure in critically ill patients: a randomized controlled crossover study

BACKGROUND

Despite intermittent control of tracheal cuff pressure (P _cuff) using a manual manometer, cuff underinflation (<20 cmH₂O) and overinflation (>30 cmH₂O) frequently occur in intubated critically ill patients, resulting in increased risk of microaspiration and tracheal ischemic lesions. The primary objective of our study was to determine the efficiency of an electronic device in continuously controlling P _cuff. The secondary objective was to determine the impact of this device on the occurrence of microaspiration of gastric or oropharyngeal secretions.

METHODS

Eighteen patients requiring mechanical ventilation were included in this prospective randomized controlled crossover study. They randomly received either continuous control of P _cuff with Mallinckrodt^® device for 24 h, followed by discontinuous control with a manual manometer for 24 h, or the reverse sequence. During the 48 h after randomization, P _cuff was continuously recorded, and pepsin and alpha amylase were quantitatively measured in tracheal aspirates. P _cuff target was 25 cmH₂O.

RESULTS

Clinical characteristics were similar during the two study periods, as well as mean airway pressure. Percentage of time spent with cuff overinflation or underinflation was significantly lower during continuous control compared with routine care period [median (IQR) 0.8 (0.1, 2) vs 20.9 (3.1, 40.1), p = 0.0009]. No significant difference was found in pepsin [median (IQR) 230 (151, 300) vs 259 (134, 368), p = 0.95] or in alpha amylase level [median (IQR) 1475 (528, 10,333) vs 2400 (1342, 15,391), p = 0.19] between continuous control and routine care periods, respectively.

CONCLUSIONS

The electronic device is efficient in controlling P _cuff, compared with routine care using a manometer. Further studies are needed to evaluate the impact of this device on intubation-related complications. Trial registration ClinicalTrials.gov Identifier: NCT01965821.

The value of polyurethane-cuffed endotracheal tubes to reduce microaspiration and intubation-related pneumonia: a systematic review of laboratory and clinical studies

Background

When conventional high-volume, low-pressure cuffs of endotracheal tubes (ETTs) are inflated, channel formation due to folds in the cuff wall can occur. These channels facilitate microaspiration of subglottic secretions, which is the main pathogenic mechanism leading to intubation-related pneumonia. Ultrathin polyurethane (PU)-cuffed ETTs are developed to minimize channel formation in the cuff wall and therefore the risk of microaspiration and respiratory infections.

Methods

We systematically reviewed the available literature for laboratory and clinical studies comparing fluid leakage or microaspiration and/or rates of respiratory infections between ETTs with polyvinyl chloride (PVC) cuffs and ETTs with PU cuffs.

Results

The literature search revealed nine in vitro experiments, one in vivo (animal) experiment, and five clinical studies. Among the 9 in vitro studies, 10 types of PU-cuffed ETTs were compared with 17 types of PVC-cuffed tubes, accounting for 67 vs. 108 experiments with 36 PU-cuffed tubes and 42 PVC-cuffed tubes, respectively. Among the clinical studies, three randomized controlled trials (RCTs) were identified that involved 708 patients. In this review, we provide evidence that PU cuffs protect more efficiently than PVC cuffs against fluid leakage or microaspiration. All studies with leakage and/or microaspiration as the primary outcome demonstrated significantly less leakage (eight in vitro and two clinical studies) or at least a tendency toward more efficient sealing (one in vivo animal experiment). In particular, high-risk patients intubated for shorter periods may benefit from the more effective sealing capacity afforded by PU cuffs. For example, cardiac surgery patients experienced a lower risk of early postoperative pneumonia in one RCT. The evidence that PU-cuffed tubes prevent ventilator-associated pneumonia (VAP) is less robust, probably because microaspiration is postponed rather than eliminated. One RCT demonstrated no difference in VAP risk between patients intubated with either PU-cuffed or PVC-cuffed tubes, and one before-after trial demonstrated a favorable reduction in VAP rates following the introduction of PU-cuffed tubes.

Conclusions

Current evidence can support the use of PU-cuffed ETTs in high-risk surgical patients, while there is only very limited evidence that PU cuffs prevent pneumonia in patients ventilated for prolonged periods.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1380-8) contains supplementary material, which is available to authorized users.