How to avoid microaspiration? A key element for the prevention of ventilator-associated pneumonia in intubated ICU patients

Critical care management of acute liver failure

The management of acute liver failure (ALF) in modern hepatology intensive care units (ICU) has improved patient outcomes. Critical care management of hepatic encephalopathy, cerebral edema, fluid and electrolytes; prevention of infections and organ support are central to improved outcomes of ALF. In particular, the pathogenesis of encephalopathy is multifactorial, with ammonia, elevated intra-cranial pressure and systemic inflammation playing a central role. Although ALF remains associated with high mortality, the availability of supportive care, including organ failure support such as plasma exchange, timely mechanical ventilation or continuous renal replacement therapy, either conservatively manages patients with ALF or offers bridging therapy until liver transplantation. Thus, appropriate critical care management has improved the likelihood of patient recovery in ALF. ICU care interventions such as monitoring of cerebral edema, fluid status assessment and interventions for sepsis prevention, nutritional support and management of electrolytes can salvage a substantial proportion of patients. In this review, we discuss the key aspects of critical care management of ALF.

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.

Effects of preoperative oral care on bacterial colonisation and halitosis in patients undergoing elective surgery: A randomised controlled study

OBJECTIVES

To evaluate the effects of single-dose chlorhexidine oral care on bacterial colonisation and halitosis in patients undergoing elective surgery.

RESEARCH METHODOLOGY

We conducted a two-arm parallel, single-blinded, randomised controlled trial. The intervention group (n = 102) received preoperative oral care with 0.12% chlorhexidine gluconate, and the control group (n = 105) received standard care. The data of the microbiological cultures between the groups were compared at the time of tracheal intubation, at extubation and 30 min after surgery. The presence of halitosis was measured using a survey questionnaire administered to the anaesthesia nurses assigned to the patients.

RESULTS

At baseline, no significant differences were found between the intervention and control groups for bacterial colonisation or halitosis. After the intervention, there was no significant difference in microbiological culture, including gram-positive, gram-negative bacilli and cocci results, between the two groups (p > 0.05). The presence of halitosis in the intervention group was significantly lower than in the control group during intubation (p < 0.0001) and at 30 min after surgery (p < 0.02). Regression analysis indicated that receiving oral was protective towards halitosis, while poor oral health was a risk factor.

CONCLUSIONS

Preoperative oral care using a single dose of chlorhexidine significantly improved the patients' halitosis in the perioperative period, but no significant effect was found on bacterial colonisation. Further studies are needed regarding the safe use of chlorhexidine for oral care.

IMPLICATION FOR CLINICAL PRACTICE

Oral hygiene using chlorhexidine could be beneficial in improving halitosis for anaesthesia personnel who take care of intubated adult patients undergoing elective surgery with general anaesthesia.

Preprocedural fasting policies for patients receiving tube feeding: A national survey

BACKGROUND

Patients who are critically ill frequently accrue substantial nutrition deficits due to multiple episodes of prolonged fasting prior to procedures. Existing literature suggests that, for most patients receiving tube feeding, the aspiration risk is low. Yet, national and international guidelines do not address fasting times for tube feeding, promoting uncertainty regarding optimal preprocedural fasting practice. We aimed to characterize current institutional fasting practices in the United States for patients with and without a secure airway, with variable types of enteral access, for representative surgical procedures.

METHODS

The survey was distributed to a purposive sample of academic institutions in the United States. Reponses were reported as restrictive (6-8 h preprocedurally) or permissive (<6 h or continued intraprocedurally) feeding policies. Differences between level 1 trauma centers and others, and between burn centers and others, were evaluated.

RESULTS

The response rate was 40.3% (56 of 139 institutions). Responses revealed a wide variability with respect to current practices, with more permissive policies reported in patients with secure airways. In patients with a secure airway, Level 1 trauma centers were significantly more likely to have permissive fasting policies for patients undergoing an extremity incision and drainage for each type of feeding tube surveyed.

CONCLUSIONS

Current hospital policies for preprocedural fasting in patients receiving tube feeds are conflicting and are frequently more permissive than guidelines for healthy patients receiving oral nutrition. Prospective research is needed to establish the safety and clinical effects of various fasting practices in tube-fed patients.

The gut microbiota composition is linked to subsequent occurrence of ventilator-associated pneumonia in critically ill patients

Ventilator-associated pneumonia (VAP) is the most frequent nosocomial infection in critically ill-ventilated patients. Oropharyngeal and lung microbiota have been demonstrated to be associated with VAP occurrence, but the involvement of gut microbiota has not been investigated so far. Therefore, the aim of this study is to compare the composition of the gut microbiota between patients who subsequently develop VAP and those who do not. A rectal swab was performed at admission of every consecutive patient into the intensive care unit (ICU) from October 2019 to March 2020. After DNA extraction, V3-V4 and internal transcribed spacer 2 regions deep-sequencing was performed on MiSeq sequencer (Illumina) and data were analyzed using Divisive Amplicon Denoising Algorithm 2 (DADA2) pipeline. Among 255 patients screened, 42 (16%) patients with invasive mechanical ventilation for more than 48 h were included, 18 (43%) with definite VAP and 24 without (57%). Patients who later developed VAP had similar gut bacteriobiota and mycobiota α-diversities compared to those who did not develop VAP. However, gut mycobiota was dissimilar (β-diversity) between these two groups. The presence of Megasphaera massiliensis was associated with the absence of VAP occurrence, whereas the presence of the fungal genus Alternaria sp. was associated with the occurrence of VAP. The composition of the gut microbiota, but not α-diversity, differs between critically ill patients who subsequently develop VAP and those who do not. This study encourages large multicenter cohort studies investigating the role of gut-lung axis and oropharyngeal colonization in the development of VAP in ICU patients. Trial registration number: NCT04131569, date of registration: 18 October 2019. IMPORTANCE The composition of the gut microbiota, but not α-diversity, differs between critically ill patients who subsequently develop ventilator-associated pneumonia (VAP) and those who do not. Investigating gut microbiota composition could help to tailor probiotics to provide protection against VAP.

Antimicrobial materials for endotracheal tubes: A review on the last two decades of technological progress

Ventilator-associated pneumonia (VAP) is an unresolved problem in nosocomial settings, remaining consistently associated with a lack of treatment, high mortality, and prolonged hospital stay. The endotracheal tube (ETT) is the major culprit for VAP development owing to its early surface microbial colonization and biofilm formation by multiple pathogens, both critical events for VAP pathogenesis and relapses. To combat this matter, gradual research on antimicrobial ETT surface coating/modification approaches has been made. This review provides an overview of the relevance and implications of the ETT bioburden for VAP pathogenesis and how technological research on antimicrobial materials for ETTs has evolved. Firstly, certain main VAP attributes (definition/categorization; outcomes; economic impact) were outlined, highlighting the issues in defining/diagnosing VAP that often difficult VAP early- and late-onset differentiation, and that generate misinterpretations in VAP surveillance and discrepant outcomes. The central role of the ETT microbial colonization and subsequent biofilm formation as fundamental contributors to VAP pathogenesis was then underscored, in parallel with the uncovering of the polymicrobial ecosystem of VAP-related infections. Secondly, the latest technological developments (reported since 2002) on materials able to endow the ETT surface with active antimicrobial and/or passive antifouling properties were annotated, being further subject to critical scrutiny concerning their potentialities and/or constraints in reducing ETT bioburden and the risk of VAP while retaining/improving the safety of use. Taking those gaps/challenges into consideration, we discussed potential avenues that may assist upcoming advances in the field to tackle VAP rampant rates and improve patient care. STATEMENT OF SIGNIFICANCE: The use of the endotracheal tube (ETT) in patients requiring mechanical ventilation is associated with the development of ventilator-associated pneumonia (VAP). Its rapid surface colonization and biofilm formation are critical events for VAP pathogenesis and relapses. This review provides a comprehensive overview on the relevance/implications of the ETT biofilm in VAP, and on how research on antimicrobial ETT surface coating/modification technology has evolved over the last two decades. Despite significant technological advances, the limited number of gathered reports (46), highlights difficulty in overcoming certain hurdles associated with VAP (e.g., persistent colonization/biofilm formation; mechanical ventilation duration; hospital length of stay; VAP occurrence), which makes this an evolving, complex, and challenging matter. Challenges and opportunities in the field are discussed.

Use of an innovative cuff pressure control and subglottic secretions drainage system in COVID-19 ARDS patients undergoing pronation

We conducted a proof of concept study where Anapnoguard endotracheal tubes and its control unit were used in 15 patients with COVID-19 acute respiratory distress syndrome. Anapnoguard system provides suction, venting, rinsing of subglottic space and controls cuff pressure detecting air leakage through the cuff. Alpha-amylase and pepsin levels, as oropharyngeal and gastric microaspiration markers, were assessed from 85 tracheal aspirates in the first 72 h after connection to the system. Oropharyngeal microaspiration occurred in 47 cases (55%). Episodes of gastric microaspiration were not detected. Patient positioning, either prone or supine, did not affect alpha-amylase and pepsin concentration in tracheal secretions. Ventilator-associated pneumonia (VAP) rate was 40%. The use of the AG system provided effective cuff pressure control and subglottic secretions drainage. Despite this, no reduction in the incidence of VAP has been demonstrated, compared to data reported in the current COVID-19 literature. The value of this new technology is worth of being evaluated for the prevention of ventilator-associated respiratory tract infections.

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.

Development and validation of ester impregnated pH strips for locating nasogastric feeding tubes in the stomach-a multicentre prospective diagnostic performance study

BACKGROUND

NG (nasogastric) tubes are used worldwide as a means to provide enteral nutrition. Testing the pH of tube aspirates prior to feeding is commonly used to verify tube location before feeding or medication. A pH at or lower than 5.5 was taken as evidence for stomach intubation. However, the existing standard pH strips lack sensitivity, especially in patients receiving feeding and antacids medication. We developed and validated a first-generation ester-impregnated pH strip test to improve the accuracy towards gastric placements in adult population receiving routine NG-tube feeding. The sensitivity was improved by its augmentation with the action of human gastric lipase (HGL), an enzyme specific to the stomach.

METHODS

We carried out a multi-centred, prospective, two-gate diagnostic accuracy study on patients who require routine NG-tube feeding in 10 NHS hospitals comparing the sensitivity of the novel pH strip to the standard pH test, using either chest X-rays or, in its absence, clinical observation of the absence of adverse events as the reference standard. We also tested the novel pH strips in lung aspirates from patients undergoing oesophageal cancer surgeries using visual inspection as the reference standard. We simulated health economics using a decision analytic model and carried out adoption studies to understand its route to commercialisation. The primary end point is the sensitivity of novel and standard pH tests at the recommended pH cut-off of 5.5.

RESULTS

A total of 6400 ester-impregnated pH strips were prepared based on an ISO13485 quality management system. A total of 376 gastric samples were collected from adult patients in 10 NHS hospitals who were receiving routine NG-tube feeding. The sensitivities of the standard and novel pH tests were respectively 49.2% (95% CI 44.1‑54.3%) and 70.2% (95% CI 65.6‑74.8%) under pH cut-off of 5.5 and the novel test has a lung specificity of 89.5% (95% CI 79.6%, 99.4%). Our simulation showed that using the novel test can potentially save 132 unnecessary chest X-rays per check per every 1000 eligible patients, or direct savings of £4034 to the NHS.

CONCLUSIONS

The novel pH test correctly identified significantly more patients with tubes located inside the stomach compared to the standard pH test used widely by the NHS.

TRIAL REGISTRATION

http://www.isrctn.com/ISRCTN11170249 , Registered 21 June 2017-retrospectively registered.

Comparison of Two Extubation Techniques in Critically Ill Adult Subjects: The ExtubAR Randomized Clinical Trial

BACKGROUND

Two orotracheal extubation techniques are described in the literature: the traditional technique and the positive-pressure technique. Although prior studies reported better clinical outcomes with the positive-pressure extubation technique, its superiority has not been extensively studied yet. This study was to determine whether the positive-pressure orotracheal extubation technique, compared with the traditional orotracheal extubation technique, reduces the incidence of major postextubation complications (up to 60 min) in critically ill adult subjects.

METHODS

This was a multi-center randomized clinical trial. Subjects age > 18 y, requiring invasive mechanical ventilation through an endotracheal tube, who met the orotracheal extubation criteria were included and randomized to traditional extubation group (removing the endotracheal tube by applying continuous endotracheal suctioning during the entire procedure) or positive-pressure group (application of pressure support mode at 15/10 cm H₂O during cuff deflation and extubation). The primary measure was postextubation major complications, defined as the clinical evidence of at least one of the following: desaturation, upper-airway obstruction, or vomiting.

RESULTS

A total of 725 subjects was randomly assigned to the traditional extubation group (n = 358) and positive-pressure group (n = 367). Seventeen subjects were eliminated and not included in the per-protocol analysis. Of 708 subjects, 185 (26.1%) developed at least one major complication. The incidence was 27.8% (96/345) in the traditional group compared with 24.5% (89/363) in the positive-pressure group. No statistically significant differences were observed between the 2 groups (absolute risk 3% [95 CI -3 to 10]; relative risk, 0.88 [95 CI 0.69-1.13], P = .32).

CONCLUSIONS

Despite the trend toward the positive-pressure group, no statistically significant differences were observed. Our findings agree with the literature in that positive-pressure extubation is a safe procedure; therefore, both techniques may be used during extubation in critically ill adult patients.

Sonographic Evaluation of Gastric Residual Volume during Enteral Nutrition in Critically Ill Patients Using a Miniaturized Ultrasound Device

Background: To assess the risk of aspiration, nutrient tolerance, and gastric emptying of patients in ICUs, gastric ultrasound can provide information about the gastric contents. Using established formulas, the gastric residual volume (GRV) can be calculated in a standardized way by measuring the gastric antrum. The purpose of this study was to determine the GRV in a cohort of enterally fed patients using a miniaturized ultrasound device to achieve knowledge about feasibility and the GRV over time during the ICU stay. The findings could contribute to the optimization of enteral nutrition (EN) therapy. Methods: A total of 217 ultrasound examinations with 3 measurements each (651 measurements in total) were performed twice daily (morning and evening) in a longitudinal observational study on 18 patients with EN in the interdisciplinary surgical ICU of Saarland University Medical Center. The measured values of the GRV were analyzed in relation to the clinical course, the nutrition, and other parameters. Results: Measurements could be performed without interrupting the flow of clinical care and without pausing EN. The GRV was significantly larger with sparsely auscultated bowel sounds than with normal and excited bowel sounds (p < 0.01). Furthermore, a significantly larger GRV was present when using a high-caloric/low-protein nutritional product compared to an isocaloric product (p = 0.02). The GRV at the morning and evening measurements showed no circadian rhythm. When comparing the first and last ultrasound examination of each patient, there was a tendency towards an increased GRV (p = 0.07). Conclusion: The GRV measured by miniaturized ultrasound devices can provide important information about ICU patients without restricting treatment procedures in the ICU. Measurements are possible while EN therapy is ongoing. Further studies are needed to establish gastric ultrasound as a management tool in nutrition therapy.

Prolonged Infusion of β-Lactams Decreases Mortality in Patients with Septic Shock: A Retrospective before-and-after Study

Septic shock substantially alters the pharmacokinetic properties of β-lactams with a subsequently high risk of insufficiently low serum concentrations and treatment failure. Considering their pharmacokinetic (PK)/pharmacodynamic (PD) index, prolonged infusions (PI) of β-lactams extend the time that the unbound fraction of the drug remains above the minimal inhibitory concentration MIC (ft _>MIC) and may improve patient survival. The present study is a monocentric, retrospective before-and-after analysis of septic shock patients treated with β-lactams. Patients of the years 2015–2017 received intermittent bolus application whereas patients of 2017–2020 received PI of β-lactams. The primary outcome was mortality at day 30 and 90 after diagnosis of septic shock. Mortality rates in the PI group were significantly lower on day 30 (PI: 41%, n = 119/290 vs. IB: 54.8%, n = 68/114; p = 0.0097) and day 90 (PI: 47.9%, n = 139/290 vs. IB: 62.9%, n = 78/124; p = 0.005). After propensity-score matching, 30- and 90-day mortality remained lower for the PI group (−10%, p = 0.14). PI was further associated with a reduction in the duration of invasive ventilation and a stronger decrease in SOFA scores within a 14 day-observation period. PI of β-lactams was associated with a significant reduction of mortality in patients with septic shock and may have beneficial effects on invasive ventilation and recovery from sepsis-related organ failure.

Effect of a Multistage Educational Skill-Based Program on Nurse's Stress and Anxiety in the Intensive Care Setting: A Randomized Controlled Trial

Background

Psychological problems such as stress and anxiety are prevalent among working nurses in the intensive care units (ICUs). This study was aimed at investigating the effects of three skill-based educational programs on stress and anxiety among critical care nurses.

Methods

Using a randomized controlled trial, 160 nurses were assigned to four groups including one control and three intervention groups. A standard skill-based educational program was delivered to three intervention groups using booklet, booklet+oral presentation, and booklet+oral presentation+clinical teaching over a period of one month to reduce different types of stress and anxiety. The control group received routine education only. Perceived stress, state anxiety, trait anxiety, and work-related stress were assessed at baseline and three times after the intervention (15 days, 3 months, and 21 months). Repeated-measure analysis of variance was used for data analysis.

Results

There was no significant change in the control group in terms of study variables during follow-up assessments, whereas measures of stress and anxiety were reduced after intervention in the trial groups except trait anxiety. Nurses in the mixed-method group (booklet+oral presentation+clinical teaching) showed less stress and anxiety during follow-ups. Although the stress and anxiety scores decreased in the first and second follow-ups, there was no significant reduction in the third follow-up.

Conclusions

To improve the mental health and performance of the intensive care unit nurses, knowledge-based and skill-based training programs seem useful. Continuous training may help to maintain the effectiveness of these programs over time.

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.

Is α-Amylase an Important Biomarker to Detect Aspiration of Oral Secretions in Ventilated Patients?

Alpha-amylase has emerged as a biomarker of interest in detecting aspiration of oral secretions. In several studies, most ventilated patients have α-amylase values detected in pulmonary secretions. Values of α-amylase are high (as expected) in oral secretions and lowest in bronchoalveolar lavage samples. Around 5-7% of oral α-amylase is detectable in tracheal secretions. Once secretions are aspirated, the duration of detection of α-amylase in pulmonary secretions is unknown. Evidence varies on the relationship between α-amylase and clinical outcomes. Although detection of α-amylase in pulmonary secretions is useful to identify that aspiration has occurred, the lack of standardized reference values, the lack of knowledge regarding duration of detection following aspiration, and mixed findings related to clinical outcomes, limit its usefulness as a measurement tool. If α-amylase is to be used in research and/or clinical practice, additional data are needed to assist in interpretation and application of findings.

Evaluation of prevention of ventilator-associated infections in four Australian intensive care units

Background

Effective approaches to practice improvement require development of tailored interventions in collaboration with knowledge users.

Objectives

To explore critical care nurses' knowledge and adherence to best practice guidelines for management of patients with an artificial airway to minimise development of ventilator-associated pneumonia.

Methods

A cross-sectional study was undertaken across four intensive care units that involved three phases: (1) survey of critical care nurses regarding their current practice; (2) observation of respiratory care delivery; and (3) chart audit. Key care processes evaluated were: (1) technique and adherence to standard precautions when performing endotracheal suction, cuff pressure checks and extubation; and (2) frequency of endotracheal suctioning and mouth care.

Results

Observational and chart audit data on the provision and documentation of respiratory care were collected for 36 nurse/patient dyads. Forty-six nurses were surveyed and the majority responded that endotracheal suctioning and mouth care should be performed 'as required' or every 2 hours (h). During observations of practice, no patient received mouth care every 2 h, nor had documentation of such. Inconsistent adherence to standard precautions and hand hygiene during respiratory care provision was observed. Chart audit indicated that nurses varied in the frequency of suctioning consistent with documented clinical assessment findings.

Conclusion

Although nurses had good knowledge for the management of artificial airways, this was not consistently translated into practice. Gaps were identified in relation to respiratory related infection prevention, the prevention of micro-aspiration of oropharyngeal secretions and in the provision of mouth care.

Non-ventilator health care-associated pneumonia (NV-HAP): Best practices for prevention of NV-HAP

Although the latest research and data show decreases in many health care-associated infections, recent publications highlight the understated but significant burden of nonventilator hospital-acquired pneumonia (NV-HAP). This section presents best practices to prevent NV-HAP. Many of the tools and interventions address basic nursing care such as oral care, oral and nonoral alimentation, patient positioning and mobility, pharmacologic and immunologic controls. The section stresses the importance of working with an interdisciplinary caregiver team to address fundamental activities of daily living that mitigate risk of developing NV-HAP.

Nurses' knowledge, experience and self-reported adherence to evidence-based guidelines for prevention of ventilator-associated events: A national online survey

OBJECTIVE

To explore Australian intensive care nurses' knowledge of ventilator-associated pneumonia and self-reported adherence to evidence-based guidelines for the prevention of ventilator-associated events.

DESIGN

A quantitative cross-sectional online survey was used.

SETTING

The study was conducted in two Australia intensive care units, in large health services in Victoria and an Australia-wide nurses' professional association (Australian College of Critical Care Nurses).

MAIN OUTCOME MEASURES

Participants' knowledge and self-reported adherence to evidence-based guidelines.

RESULTS

The median knowledge score was 6/10 (IQR: 5-7). There was a significant positive association between completion of post graduate qualification and their overall knowledge score p = 0.014). However, there was no association (p = 0.674) between participants' years of experience in intensive care nursing and their overall score. The median self-reported adherence was 8/10 (IQR: 6-8). The most adhered to procedures were performing oral care on mechanically ventilated patients (n = 259, 90.9%) and semi-fowlers positioning of the patient (n = 241, 84.6%). There was no relationship between participants' knowledge and adherence to evidence-based guidelines (p = 0.144).

CONCLUSION

Participants lack knowledge of evidence-based guidelines for the prevention of ventilator-associated pneumonia. Specific education on ventilator-associated events may improve awareness and guideline adherence.

An endotracheal tube providing "pressurized sealing" prevents fluid leakage in mechanically ventilated critically ill patients: a pilot study

Microaspiration of bacteriologically contaminated oropharyngeal secretions alongside the cuff of an endotracheal tube (ETT) is a key mechanism for development of ventilator-associated pneumonia. We have constructed a prototype double-cuffed ETT equipped with a supplemental port in-between the cuffs through which continuous positive airway pressure (CPAP) is delivered. Pressure in the intercuff space propels secretions upwards and produces 100% tracheal sealing in an in vitro model. We conducted a 24 h study to investigate the sealing effect of this ETT in 12 critically ill mechanically ventilated patients. Methylene blue, instilled through a bronchoscope on top of the proximal cuff, was used as leakage tracer. Fiberoptic visualisation of the trachea was performed 1 h and 24 h thereafter. Leakage was confirmed if blue dye was detected on the tracheal mucosa beyond the tip of the ETT. In no patient, dye passed by the cuffs during the study period. Presence of the ETT did not interfere with ventilator settings, patient mobilization, physiotherapy, and technical acts. Overall, pressures in the intercuff space remained between 10 and 15 cmH₂O. Excessive pressure swings were swiftly corrected by the CPAP system. A double-cuffed ETT, offering “pressurized sealing” of the trachea, safely and effectively prevented leakage during 24 h mechanical ventilation.

Impact of deep oropharyngeal suctioning on microaspiration, ventilator events, and clinical outcomes: A randomized clinical trial

AIMS

To evaluate a deep oropharyngeal suction intervention (NO-ASPIRATE) in intubated patients on microaspiration, ventilator-associated events and clinical outcomes.

DESIGN

Prospective, two-group, single-blind, randomized clinical trial.

METHODS

The study was conducted between 2014 - 2017 in 513 participants enroled within 24 hr of intubation and randomized into NO-ASPIRATE or usual care groups. Standard oral care was provided to all participants every 4 hr and deep oropharyngeal suctioning was added to the NO-ASPIRATE group. Oral and tracheal specimens were obtained to quantify α-amylase as an aspiration biomarker.

RESULTS

Data were analysed for 410 study completers enrolled at least 36 hr: NO-ASPIRATE (N = 206) and usual care (N = 204). Percent of tracheal specimens positive for α-amylase, mean tracheal α-amylase levels over time and ventilator-associated events were not different between groups. The NO-ASPIRATE group had a shorter hospital length of stay and a subgroup with moderate aspiration at baseline had significantly lower α-amylase levels across time.

CONCLUSION

Hospital length of stay was shorter in the NO-ASPIRATE group and a subgroup of intervention participants had lower α-amylase across time. Delivery of standardized oral care to all participants may have been an intervention itself and possibly associated with the lack of significant findings for most outcomes.

IMPACT

This trial compared usual care to oral care with a deep suctioning intervention on microaspiration and ventilator-associated events, as this has not been systematically studied. Further research on the usefulness of α-amylase as an aspiration biomarker and the role of oral suctioning, especially for certain populations, is indicated.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT02284178.

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.

A comparative study of risk of pneumonia and mortalities between nasogastric and jejunostomy feeding routes in surgical critically ill patients with perforated peptic ulcer

INTRODUCTION

Enteral nutrition (EN) is important in the management of critically illness. Yet, the best route (e.g. pre-pyloric or post-pyloric) for EN in critically ill patients remains to be investigated, especially in specific surgical patients group. In addition, EN could be associated with a higher risk of aspiration pneumonia. Therefore, we evaluate the effect of various EN routes in surgical critically ill perforated peptic ulcer (PPU) patients who underwent surgery and required mechanical ventilation.

METHOD

We collected data of surgical critically ill PPU patients admitted to intensive care unit. The patients were managed with appropriate care bundle and program. To reduce the impact of surgery types, we excluded those who had received other surgical procedures and included patients that only received simple closure. Patients were classified into nasogastric and jejunostomy feeding groups. The demographics, severity scores (e.g.: APACHE II, SOFA, and POSSUM), body mass index (BMI), comorbidities, ventilator days, use of proton pump inhibitors (PPIs), pneumonia occurrence, mortality and complications were collected for analysis.

RESULTS

A total of 136 critically ill PPU patients that received surgery and mechanical ventilation were enrolled. There were 53 patients in NG group and 83 patients in FJ group. There were no differences in demographics, severity scores, BMI, comorbidities, ventilator days, use of PPIs, pneumonia occurrence, mortalities and complications between groups.

CONCLUSION

Our study indicates that there are no differences in mortalities and pneumonia occurrence using nasogastric or feeding jejunostomy in surgical critically ill PPU patients underwent surgery. However, further studies are required.

Risk factors for ventilator-associated events: A prospective cohort study

BACKGROUND

In January 2013, the Centers for Disease Control and Prevention released new surveillance definitions for ventilator-associated event (VAE) to replace ventilator-associated pneumonia (VAP) in adult patients. VAEs are associated with prolonged mechanical ventilation and hospital death, but little is known about their risk factors and how best to prevent them.

METHODS

We compared VAE cases with non-VAE cases with regard to demographics, comorbidities, sedative exposures, opioids exposures, paralytic exposures, routes of nutrition, blood products, gastric retention, and fluid balance. Patients mechanically ventilated for ≥4 days between January 1, 2017, and December 31, 2017, in 2 adult intensive care units of a tertiary care teaching hospital in China were included.

RESULTS

On multivariable logistic regression, significant risk factors for VAEs were positive daily fluid balances of ≥ 50 mL between day of intubation and the fourth day of mechanical ventilation (relative risk [RR], 8.39; 95% confidence interval [CI], 2.99-23.50), sedative administered between the first day and the fourth day of invasive mechanical ventilation (RR, 15.69; 95% CI, 1.62-152.06), and daily gastric retention of ≥200 mL between day of intubation and the fourth day of mechanical ventilation (RR, 9.27; 95% CI, 1.89-45.47).

CONCLUSIONS

Positive daily fluid balances of ≥50 mL, sedatives administered, and gastric retention of ≥200 mL are risk factors for VAEs. Intervention studies are needed to determine if targeting these risk factors can lower VAE rates.

Impact of nutrition route on microaspiration in critically ill patients with shock: a planned ancillary study of the NUTRIREA-2 trial

BACKGROUND

Microaspiration of gastric and oropharyngeal secretions is the main mechanism of entry of bacteria into the lower respiratory tract in intubated critically ill patients. The aim of this study is to determine the impact of enteral nutrition, as compared with parenteral nutrition, on abundant microaspiration of gastric contents and oropharyngeal secretions.

METHODS

Planned ancillary study of the randomized controlled multicenter NUTRIREA2 trial. Patients with shock receiving invasive mechanical ventilation were randomized to receive early enteral or parenteral nutrition. All tracheal aspirates were collected during the 48 h following randomization. Abundant microaspiration of gastric contents and oropharyngeal secretions was defined as the presence of significant levels of pepsin (> 200 ng/ml) and salivary amylase (> 1685 UI/ml) in > 30% of tracheal aspirates.

RESULTS

A total of 151 patients were included (78 and 73 patients in enteral and parenteral nutrition groups, respectively), and 1074 tracheal aspirates were quantitatively analyzed for pepsin and amylase. Although vomiting rate was significantly higher (31% vs 15%, p = 0.016), constipation rate was significantly lower (6% vs 21%, p = 0.010) in patients with enteral than in patients with parenteral nutrition. No significant difference was found regarding other patient characteristics. The percentage of patients with abundant microaspiration of gastric contents was significantly lower in enteral than in parenteral nutrition groups (14% vs 36%, p = 0.004; unadjusted OR 0.80 (95% CI 0.69, 0.93), adjusted OR 0.79 (0.76, 0.94)). The percentage of patients with abundant microaspiration of oropharyngeal secretions was significantly higher in enteral than in parenteral nutrition groups (74% vs 54%, p = 0.026; unadjusted OR 1.21 (95% CI 1.03, 1.44), adjusted OR 1.23 (1.01, 1.48)). No significant difference was found in percentage of patients with ventilator-associated pneumonia between enteral (8%) and parenteral (10%) nutrition groups (HR 0.78 (0.26, 2.28)).

CONCLUSIONS

Our results suggest that enteral and parenteral nutrition are associated with high rates of microaspiration, although oropharyngeal microaspiration was more common with enteral nutrition and gastric microaspiration was more common with parenteral nutrition.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03411447 . Registered 18 July 2017. Retrospectively registered.

Endotracheal tube cuff pressure changes during manual cuff pressure control manoeuvres: An in-vitro assessment

BACKGROUND

Endotracheal tube (ETT) cuffs are designed to seal the lower airway for precise ventilation and to protect against ingress of pathogens from the pharyngeal space. Therefore, a minimal continuous cuff pressure must be maintained. Aim of this study was to analyse the course of cuff pressure in an in-vitro model during manual cuff pressure control manoeuvres.

METHODS

An artificial trachea was intubated with an appropriately sized ETT and cuff pressure set to 20 cm H₂ O. Thirty-two experienced ICU nurses each performed six cuff pressure control manoeuvres (three times in two different ETTs) using a manual cuff pressure manometer. Course of cuff pressure from connecting the manometer to disconnecting it from the cuff pilot balloon was recorded using a pressure transducer.

RESULTS

There were 190 cuff pressure control manoeuvres suitable for analysis. In all control manoeuvres a cuff pressure below 20 cm H₂ O was noted. In 20.0% of the control manoeuvres the cuff pressure dropped below 10 cm H₂ O. Cuff pressure drops were mainly caused by initially connecting the manometer to the pilot balloon, less frequently by manipulating the pressure gauge of the manometer. Disconnecting the manometer after the control manoeuvre caused a cuff pressure drop in 78.1% of cases, contributing to a final cuff pressure below 20 cm H₂ O in 31.3% of control manoeuvres.

CONCLUSION

Routine manual cuff pressure control manoeuvres in ETT cuffs result in considerable cuff pressure drops. This may have an impact on silent aspiration of pharyngeal contents passing along the cuff into the lower airway.

Predictors and microbiology of ventilator-associated pneumonia among patients with exacerbation of chronic obstructive pulmonary disease

Background

Understanding the risk factors and microbiology of ventilator-associated pneumonia (VAP) among patients with chronic obstructive pulmonary disease (COPD) is important for the application of preventive and therapeutic interventions. Therefore, this study was planned to assess the clinical predictors and microbiological features of VAP among COPD patients.

Materials and Methods

This prospective study involved patients with exacerbation of COPD who required mechanical ventilation and admitted in respiratory intensive care unit at a tertiary care teaching hospital. Various baseline demographic and clinical features were compared between patients with VAP and without VAP. Univariate and multivariable analyses were done to assess the impact of demographic and clinical features on the development of VAP.

Results

The study included 100 intubated patients with age (mean ± standard deviation [SD]) of 62.45 ± 8.32 years, duration (median) of COPD of 6 years, and Acute Physiology, Age, and Chronic Health Evaluation score (mean ± SD) of 18.60 ± 4.30. In this cohort, 17 patients developed VAP. Multivariable analysis showed that Sequential Organ Failure Assessment (SOFA) score at admission, re-intubation, and history of previous hospitalization were independent predictors of VAP with odds ratio (95% confidence interval) of 2.70 (1.24, 5.63; P = 0.012), 66.96 (4.86, 922.72; P = 0.002), and 35.92 (2.84, 454.63; P = 0.006), respectively. Acinetobacter baumannii was the most frequent organism (n = 8; 47%), followed by Klebsiella pneumoniae (n = 5; 29%), Pseudomonas aeruginosa (n = 1; 6%), and Enterobacter spp. (n = 1; 6%). All organisms were multidrug resistant (MDR).

Conclusions

SOFA score at admission, re-intubation, and history of previous hospitalization were independent predictors of VAP. Antimicrobial therapy for VAP should cover MDR Gram-negative organisms.

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.

Ventilator-associated pneumonia: The central role of transcolonization

Ventilator-associated pneumonia remain frequent and serious diseases since they are associated with considerable crude mortality. Pathophysiology is centered on modifications of regional bacterial flora, especially tracheobronchial tree and oropharyngeal sphere. Bacterial migration from an anatomical area to another seems to be the main explanation of these alterations which are called "transcolonization". The association of transcolonization and lack of tightness of the endotracheal tube cuff provides a direct pathway for bacteria from the upper to the subglottic airways, eventually leading to ventilator-associated pneumonia. Although modification of bacterial flora has been largely studied, the mechanism which underlays the ability of the implantation, growing and interactions with the local microbiome that leads to the observed transcolonization remains to be more clearly deciphered. The aim of our review is to emphasize the cornerstone importance of the "transcolonization" as a nosological entity playing a central role in ventilator-associated pneumonia.

APACHE II score for critically ill patients with a solid tumor: A reclassification study

OBJECTIVE

To improve the accuracy of the Acute Physiology and Chronic Health Evaluation (APACHE) II model for predicting hospital mortality in critically ill cancer patients.

MATERIALS AND METHODS

This was a prospective cohort study of 522 patients admitted to ICU with a solid tumor. We developed the "APACHE II score for critically ill patients with a solid tumor" (APACHE II_CCP score), in which typical variables of critically ill cancer patients were added to general APACHE II score. Calibration and discrimination were evaluated by Hosmer-Lemeshow test (H-L) and area under receiver operating characteristic curve (AROC), respectively. The improvement in predicting hospital mortality with the new model was assessed using a reclassification analysis by integrated discrimination improvement (IDI), net reclassification improvement (NRI; cut-off point of 20% in risk of death) and quantitative NRI (qNRI).

RESULTS

The hospital mortality rate was 13%. Discrimination was superior for APACHE II_CCP score (AROC=0.91 [95% CI 0.87-0.94; P<.0001]) compared to general APACHE II score (AROC=0.62 [95% CI 0.54-0.70; P=.002]). Calibration was better using APACHE II_CCP score (H-L; P=.267 vs. P=.001). In reclassification analysis, an improved mortality prediction was observed with APACHE II_CCP score (IDI=0.2994 [P<.0001]; total qNRI=134.3% [95% CI 108.8-159.8%; P<.0001]; total NRI=41.5% [95% CI 23.7-59.3%; P<.0001]).

CONCLUSIONS

The performance of APACHE II_CCP score was superior to that observed for general APACHE II score in predicting mortality in critically ill patients with a solid tumor. Other studies validating this new predictive model are required.

High rates of methicillin-resistant Staphylococcus aureus colonisation in a Brazilian Intensive Care Unit

OBJECTIVE

To evaluate the colonisation rate of Staphylococcus aureus in the oropharynx and the insertion site of central venous catheters in intensive care unit patients.

DESIGN

Cross-sectional study.

SETTING

Brazilian intensive care unit.

MEASUREMENTS

Samples were collected from October to December 2015 from the oropharyngeal cavity and central venous catheter insertion site of 110 patients. Samples that presented growth of Staphylococcus aureus were isolated and their sensitivity profiles were tested for several antimicrobials.

FINDINGS

The study participants (110) were mostly females older than 60 years (53.6%). The mean length of hospitalisation was 15.5 days (±31.3). A total of 188 biological samples were collected: 110 collected from the oropharynx and 78 from the central venous catheter insertion site. A 35% (n = 38/110) S. aureus colonisation rate of the patients was observed in at least one collection site. In the oropharynx alone, a 31% rate (n = 34/110) was found, and a 12.8% rate (n = 10/78) at central venous catheter insertion sites only. MRSA colonisation in the oropharynx or at the central venous catheter occurred in 29 (26.4%) patients and vancomycin resistant Staphylococcus aureus was present in 24 (22.4%) of the patients studied. Patients hospitalised for seven days or more were 4.8 times more likely to be colonised compared to patients hospitalised less than seven days (95% CI = 1.2-28.5).

CONCLUSION

The oropharynx and the central venous catheter are important reservoirs of this bacterium that in critical conditions may become pathogenic. The data showed a high degree of resistance of the bacterial populations isolated to different drugs, which may hinder the control of these organisms.

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.

Impact of selective digestive decontamination without systemic antibiotics in a major heart surgery intensive care unit

PURPOSE

The incidence density of ventilator-associated pneumonia (VAP) is higher in patients undergoing major heart surgery than in other populations, despite the introduction of bundles of preventive measures, because many risk factors are not amenable to intervention. Selective digestive decontamination (SDD) has been shown to be efficacious for decreasing the frequency of VAP, although it has not been incorporated into the routine of most intensive care units. The objective of our study was to evaluate the efficacy of SDD without parenteral antibiotics for preventing VAP in a major heart surgery intensive care unit.

METHODS

We compared the incidence of VAP before the introduction of SDD (17 months) and during the 17 months after the introduction of SDD and examined its ecologic influence.

RESULTS

The rates of VAP in the overall population before and during the intervention were 16.26/1000 days and 6.80 episodes/1000 days of mechanical ventilation, respectively (P = .01). The rates of VAP in the 173 patients remaining under mechanical ventilation > 48 hours after surgery were, respectively, 25.85/1000 days of mechanical ventilation versus 12.06 episodes/1000 days of mechanical ventilation (P = .04). We found a significant reduction in the number of patients with multidrug-resistant microorganisms (P = .01) in the second period of the study.

CONCLUSIONS

Our study shows that SDD without parenteral antibiotics can reduce the incidence of VAP in high-risk patients after major heart surgery, with no significant ecologic influence.

Efficacy of a bundle approach in preventing the incidence of ventilator associated pneumonia (VAP)

Ventilator-associated pneumonia (VAP) is a potentially preventable iatrogenic illness that may develop following mechanical ventilation. A bundle for the prevention of VAP consists of different measures which may vary between institutions, and may include: elevation of the head of the bed, oral care with chlorhexidine, subglottic suctioning, daily assessment for extubation and the need for proton-pump inhibitors, use of closed suction systems, and maintaining endotracheal cuff pressure at 25 cmH2O. Our aim was to determine the efficacy of a VAP prevention bundle, consisting of the above-mentioned measures, by evaluating the incidence of VAP before (no-VAP-B group) and after (VAP-B group) the introduction of the bundle. We retrospectively evaluated the data for patients who were mechanically ventilated with an endotracheal tube, in the period between 1 September and 31 December 2014 (no-VAP-B group, n = 55, 54.5% males, mean age 67.8 ± 14.5 years) and between 1 January to 30 April 2015 (VAP-B group, n = 74, 62.1% males, mean age 64.8 ± 13.7 years). There were no statistically significant differences between no-VAP-B and VAP-B groups in demographic data, intensive care unit (ICU) mortality, hospital mortality, duration of ICU treatment, and duration of mechanical ventilation. No significant differences in the rates of VAP and early VAP (onset ≤7 days after intubation) were found between no-VAP-B and VAP-B groups (41.8% versus 25.7%, p = 0.06 and 10.9% versus 12.2%, p > 0.99, respectively). However, a significant decrease in the late VAP (onset >8 days after intubation) was found in VAP-B group compared to no-VAP-B group (13.5% versus 30.9%, p = 0.027). Overall, our results support the use of VAP prevention bundle in clinical practice.

Clinical characteristics and outcomes of cancer patients requiring intensive care unit admission: a prospective study

PURPOSE

The study was aimed to describe the characteristics of cancer patients admitted to the oncological ICU and to identify clinical features associated with outcomes.

METHODS

This is a prospective study (January 2014 to December 2015) of 522 cancer patients consecutively admitted to the oncological ICU. Patients with a length of oncological ICU stay ≤ 1 day were excluded. Demographic and clinical variables were obtained at oncological ICU admission. The primary outcome of interest was hospital mortality. Logistic regression analysis was performed to identify independent risk factors for hospital mortality.

RESULTS

The study cohort consisted of 492 (94.3%) patients with solid tumours and 30 patients (5.7%) with haematological malignancies. Advanced cancer was observed in 53.3%. Unplanned admission accounted for 25.3%. Hospital mortality rate was 13.0% (n = 68), and it was higher for patients with unplanned admission than those for electively admitted patients (35.6% vs. 5.4; p < 0.0001). Stage IV of cancer (OR 5.28; 95% CI 2.71-10.28; p < 0.0001), patients from the emergency department (OR 3.33; 95% CI 1.68-6.61; p = 0.001), unplanned admission (OR 7.99; 95% CI 4.45-14.33; p < 0.0001), non-malignancy-related admission (OR 5.80; 95% CI 3.26-10.32; p < 0.0001), sepsis (OR 4.81; 95% CI 2.28-10.16; p < 0.0001), chemotherapy-induced adverse event (OR 5.64; 95% CI 2.33-13.66; p < 0.0001), and invasive mechanical ventilation (OR 18.70; 95% CI 9.93-35.21; p < 0.0001) were independently associated with increased hospital mortality in multivariate logistic regression analysis.

CONCLUSIONS

ICU admission of cancer patients should be based on potential chance of recovering from the acute problem. Clinical predictor for mortality could support this purpose (UIN: researchregistry3484).

Orotracheal tube as a risk factor for lower respiratory tract infection: preliminary data from a randomised trial

PURPOSE

The aim of the study was to investigate whether polyurethane (PU) endotracheal tubes, continuous measurements of cuff pressure and aspiration of the subglottic space as a bundle of parameters could reduce patients' risk for developing ventilator associated pneumonia (VAP).

METHODS

Two groups of patients that differed only in terms of endotracheal tubes and intubation intervention were compared. Group A was ventilated using PU tubes a with conical cuff; they also had continuous cuff pressure measurement and continuous subglottic aspiration. Group B was ventilated using PVC tubes with a cylindrical cuff; the patients underwent intermittent cuff pressure measurement and intermittent subglottic aspiration.

RESULTS

Seven patients in group A (13.2%) and 18 in group B (36.0%) out of 103 were diagnosed with VAP. VAP patients were in general older, stayed longer in the ICU and were ventilated significantly longer compared with the patients with no VAP. Eight more patients in group B died compared with group A. Moreover, subjects in group A survived longer. Patient age, hours on mechanical ventilation, and days on an ICU were all positively associated with the occurrence of VAP.

CONCLUSIONS

Prevention parameters in ventilation (PU cuff, conical cuff, continuous subglottic drainage and continuous cuff pressure measurement) could prevent the incidence of VAP in ICU patients.

Optimization of Endotracheal Tube Cuff Pressure by Monitoring CO2 Levels in the Subglottic Space in Mechanically Ventilated Patients: A Randomized Controlled Trial

BACKGROUND

Many of the complications of mechanical ventilation are related to inappropriate endotracheal tube (ETT) cuff pressure. The aim of the current study was to evaluate the effectiveness of automatic cuff pressure closed-loop control in patients under prolonged intubation, where presence of carbon dioxide (CO2) in the subglottic space is used as an indicator for leaks. The primary outcome of the study is leakage around the cuff quantified using the area under the curve (AUC) of CO2 leakage over time.

METHODS

This was a multicenter, prospective, randomized controlled, noninferiority trial including intensive care unit patients. All patients were intubated with the AnapnoGuard ETT, which has an extra lumen used to monitor CO2 levels in the subglottic space.The study group was connected to the AnapnoGuard system operating with cuff control adjusted automatically based on subglottic CO2 (automatic group). The control group was connected to the AnapnoGuard system, while cuff pressure was managed manually using a manometer 3 times/d (manual group). The system recorded around cuff CO2 leakage in both groups.

RESULTS

Seventy-two patients were recruited and 64 included in the final analysis. The mean hourly around cuff CO2 leak (mm Hg AUC/h) was 0.22 ± 0.32 in the manual group and 0.09 ± 0.04 in the automatic group (P = .01) where the lower bound of the 1-sided 95% confidence interval was 0.05, demonstrating noninferiority (>-0.033). Additionally, the 2-sided 95% confidence interval was 0.010 to 0.196, showing superiority (>0.0) as well. Significant CO2 leakage (CO2 >2 mm Hg) was 0.027 ± 0.057 (mm Hg AUC/h) in the automatic group versus 0.296 ± 0.784 (mm Hg AUC/h) in the manual group (P = .025). In addition, cuff pressures were in the predefined safety range 97.6% of the time in the automatic group compared to 48.2% in the automatic group (P < .001).

CONCLUSIONS

This study shows that the automatic cuff pressure group is not only noninferior but also superior compared to the manual cuff pressure group. Thus, the use of automatic cuff pressure control based on subglottic measurements of CO2 levels is an effective method for ETT cuff pressure optimization. The method is safe and can be easily utilized with any intubated patient.

Risk factors and outcomes of severe acute respiratory failure requiring invasive mechanical ventilation in cancer patients: A retrospective cohort study

OBJECTIVES

To determine the risk factors for severe acute respiratory failure requiring invasive mechanical ventilation (SARF-MV) and its effect upon clinical outcomes in critically ill cancer patients.

DESIGN

A retrospective cohort study was carried out.

SETTING

A 12-bed oncological intensive care unit (ICU) from January 2014 to December 2015.

PATIENTS

A total of 878 consecutive cancer patients were included. Patients with an ICU stay of ≤1 day were excluded. The final sample size was 691 patients.

INTERVENTIONS

None.

VARIABLES

Clinical variables at ICU admission were extracted from the medical records. The primary outcome was SARF-MV. We also measured ICU and hospital mortality, as well as length of stay.

RESULTS

The SARF-MV rate was 15.8%. The multivariate analysis identified brain tumour (OR 14.54; 95%CI 3.86-54.77; p<0.0001), stage IV cancer (OR 3.47; 95%CI 1.26-9.54; p=0.016), sepsis upon admission (OR 2.28; 95%CI 1.14-4.56; p=0.020) and an APACHE II score≥20 points (OR 5.38; 95%CI 1.92-15.05; p=0.001) as being independently associated to SARF-MV. Compared with the patients without SARF-MV, those with SARF-MV had a prolonged length of ICU stay (p<0.0001), a lower ICU survival rate (p<0.0001) and a lower hospital survival rate (p<0.0001).

CONCLUSIONS

A number of clinical factors are related to SARF-MV. In this regard, SARF-MV is a powerful factor independently correlated to poor outcomes. Future studies should investigate means for preventing SARF-MV in critically ill cancer patients, which may have an impact upon outcomes.

Pathogenic Link Between Postextubation Pneumonia and Ventilator-Associated Pneumonia: An Experimental Study

BACKGROUND

The presence of an endotracheal tube is the main cause for developing ventilator-associated pneumonia (VAP), but pneumonia can still develop in hospitalized patients after endotracheal tube removal (postextubation pneumonia [PEP]). We hypothesized that short-term intubation (24 hours) can play a role in the pathogenesis of PEP. To test such hypothesis, we initially evaluated the occurrence of lung colonization and VAP in sheep that were intubated and mechanically ventilated for 24 hours. Subsequently, we assessed the incidence of lung colonization and PEP at 48 hours after extubation in sheep previously ventilated for 24 hours.

METHODS

To simulate intubated intensive care unit patients placed in semirecumbent position, 14 sheep were intubated and mechanically ventilated with the head elevated 30° above horizontal. Seven of them were euthanized after 24 hours (Control Group), whereas the remaining were euthanized after being awaken, extubated, and left spontaneously breathing for 48 hours after extubation (Awake Group). Criteria of clinical diagnosis of pneumonia were tested. Microbiological evaluation was performed on autopsy in all sheep.

RESULTS

Only 1 sheep in the Control Group met the criteria of VAP after 24 hours of mechanical ventilation. However, heavy pathogenic bacteria colonization of trachea, bronchi, and lungs (range, 10-10 colony-forming unit [CFU]/g) was reported in 4 of 7 sheep (57%). In the Awake Group, 1 sheep was diagnosed with VAP and 3 developed PEP within 48 hours after extubation (42%), with 1 euthanized at 30 hours because of respiratory failure. On autopsy, 5 sheep (71%) confirmed pathogenic bacterial growth in the lower respiratory tract (range, 10-10 CFU/g).

CONCLUSIONS

Twenty-four hours of intubation and mechanical ventilation in semirecumbent position leads to significant pathogenic colonization of the lower airways, which can promote the development of PEP. Strategies directed to prevent pathogenic microbiological colonization before and after mechanical ventilation should be considered to avert the onset of PEP.

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.