Effect of Intensive vs Moderate Alveolar Recruitment Strategies Added to Lung-Protective Ventilation on Postoperative Pulmonary Complications: A Randomised Clinical Trial

This randomised clinical trial by Costa Leme et al was published in JAMA: Journal of the American Medical Association in April 2017.  The published copy is available in Rotherham Health Care Library.  The full text of the article can be accessed with a Rotherham NHS Athens Password via this link.

Perioperative lung-protective ventilation has been recommended to reduce pulmonary complications after cardiac surgery. The protective role of a small tidal volume (VT) has been established, whereas the added protection afforded by alveolar recruiting strategies remains controversial.

Objective:  To determine whether an intensive alveolar recruitment strategy could reduce postoperative pulmonary complications, when added to a protective ventilation with small VT.

Design, Setting, and Participants:  Randomized clinical trial of patients with hypoxemia after cardiac surgery at a single ICU in Brazil (December 2011-2014).

Interventions:  Intensive recruitment strategy (n=157) or moderate recruitment strategy (n=163) plus protective ventilation with small VT.

Outcomes and Measures:  Severity of postoperative pulmonary complications computed until hospital discharge, analyzed with a common odds ratio (OR) to detect ordinal shift in distribution of pulmonary complication severity score (0-to-5 scale, 0, no complications; 5, death). Prespecified secondary outcomes were length of stay in the ICU and hospital, incidence of barotrauma, and hospital mortality.

Results:  All 320 patients (median age, 62 years; IQR, 56-69 years; 125 women [39%]) completed the trial. The intensive recruitment strategy group had a mean 1.8 (95% CI, 1.7 to 2.0) and a median 1.7 (IQR, 1.0-2.0) pulmonary complications score vs 2.1 (95% CI, 2.0-2.3) and 2.0 (IQR, 1.5-3.0) for the moderate strategy group. Overall, the distribution of primary outcome scores shifted consistently in favor of the intensive strategy, with a common OR for lower scores of 1.86 (95% CI, 1.22 to 2.83; P = .003). The mean hospital stay for the moderate group was 12.4 days vs 10.9 days in the intensive group (absolute difference, -1.5 days; 95% CI, -3.1 to -0.3; P = .04). The mean ICU stay for the moderate group was 4.8 days vs 3.8 days for the intensive group (absolute difference, -1.0 days; 95% CI, -1.6 to -0.2; P = .01). Hospital mortality (2.5% in the intensive group vs 4.9% in the moderate group; absolute difference, -2.4%, 95% CI, -7.1% to 2.2%) and barotrauma incidence (0% in the intensive group vs 0.6% in the moderate group; absolute difference, -0.6%; 95% CI, -1.8% to 0.6%; P = .51) did not differ significantly between groups.

Conclusions and Relevance:  Among patients with hypoxemia after cardiac surgery, the use of an intensive vs a moderate alveolar recruitment strategy resulted in less severe pulmonary complications while in the hospital.

Patients’ experience of thirst while being conscious and mechanically ventilated

Kjeldsen, C.L. et al. Nursing in Critical Care. Published online: 25 January 2017

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Background: Because of changes in sedation strategies, more patients in the intensive care unit (ICU) are conscious. Therefore, new and challenging tasks in nursing practice have emerged, which require a focus on the problems that patients experience. Thirst is one such major problem, arising because the mechanical ventilator prevents the patients from drinking when they have the urge to do so. To gain a deeper understanding of the patients’ experiences and to contribute new knowledge in nursing care, this study focuses on the patients’ experiences of thirst during mechanical ventilation (MV) while being conscious.

Conclusion: Patients associate feelings of desperation, anxiety and powerlessness with the experience of thirst. These feelings have a negative impact on their psychological well-being. A strategy in the ICU that includes no sedation for critically ill patients in need of MV introduces new demands on the nurses who must care for patients who are struggling with thirst.

Relevance to clinical practice: This study shows that despite several practical attempts to relieve thirst, it remains a paramount problem for the patients. ICU nurses need to increase their focus on issues of thirst and dry mouth, which are two closely related issues for the patients. Communication may be a way to involve the patients, recognize and draw attention to their problem.

Read the full abstract here

Does ventilator-associated event surveillance detect ventilator-associated pneumonia in intensive care units? A systematic review and meta-analysis

Fan, Y. et al. Critical Care. Published online: 24 October 2016

Background: Ventilator-associated event (VAE) is a new surveillance paradigm for monitoring complications in mechanically ventilated patients in intensive care units (ICUs). The National Healthcare Safety Network replaced traditional ventilator-associated pneumonia (VAP) surveillance with VAE surveillance in 2013. The objective of this study was to assess the consistency between VAE surveillance and traditional VAP surveillance.

Methods: We systematically searched electronic reference databases for articles describing VAE and VAP in ICUs. Pooled VAE prevalence, pooled estimates (sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV)) of VAE for the detection of VAP, and pooled estimates (weighted mean difference (WMD) and odds ratio ([OR)) of risk factors for VAE compared to VAP were calculated.

Results: From 2191 screened titles, 18 articles met our inclusion criteria, representing 61,489 patients receiving mechanical ventilation at ICUs in eight countries. The pooled prevalence rates of ventilator-associated conditions (VAC), infection-related VAC (IVAC), possible VAP, probable VAP, and traditional VAP were 13.8 %, 6.4 %, 1.1 %, 0.9 %, and 11.9 %, respectively. Pooled sensitivity and PPV of each VAE type for VAP detection did not exceed 50 %, while pooled specificity and NPV exceeded 80 %. Compared with VAP, pooled ORs of in-hospital death were 1.49 for VAC and 1.76 for IVAC; pooled WMDs of hospital length of stay were −4.27 days for VAC and −5.86 days for IVAC; and pooled WMDs of ventilation duration were −2.79 days for VAC and −2.89 days for IVAC.

Conclusions: VAE surveillance missed many cases of VAP, and the population characteristics identified by the two surveillance paradigms differed. VAE surveillance does not accurately detect cases of traditional VAP in ICUs.

Read the full article here

Dexmedetomidine Use in Critically Ill Children With Acute Respiratory Failure

This research by Grant et al was published online in Pediatric Critical Care Medicine in September 2016.  The full text of the article is available to subscribers via this link.  Registered members of the library can request the full text online via this link

Objective: Care of critically ill children includes sedation but current therapies are suboptimal. To describe dexmedetomidine use in children supported on mechanical ventilation for acute respiratory failure.

Design: Secondary analysis of data from the Randomized Evaluation of Sedation Titration for Respiratory Failure clinical trial.

Patients and Setting: Data from 2,449 children; 2 weeks to 17 years old in thirty one PICUs.

Interventions: Sedation practices were unrestrained in the usual care arm. Patients were categorized as receiving dexmedetomidine as a primary sedative, secondary sedative, periextubation agent, or never prescribed. Dexmedetomidine exposure and sedation and clinical profiles are described.

Measurements and Main Results: Of 1,224 usual care patients, 596 (49%) received dexmedetomidine. Dexmedetomidine as a primary sedative patients (n = 138; 11%) were less critically ill (Pediatric Risk of Mortality III-12 score median, 6 [interquartile range, 3-11]) and when compared with all other cohorts, experienced more episodic agitation. In the intervention group, time in sedation target improved from 28% to 50% within 1 day of initiating dexmedetomidine as a primary sedative. Dexmedetomidine as a secondary sedative usual care patients (n = 280; 23%) included more children with severe pediatric acute respiratory distress syndrome or organ failure. Dexmedetomidine as a secondary sedative patients experienced more inadequate pain (22% vs 11%) and sedation (31% vs 16%) events. Dexmedetomidine as a periextubation agent patients (n = 178; 15%) were those known to not tolerate an awake, intubated state and experienced a shorter ventilator weaning process (2.1 vs 2.3 d).

Conclusions: Our data support the use of dexmedetomidine as a primary agent in low criticality patients offering the benefit of rapid achievement of targeted sedation levels. Dexmedetomidine as a secondary agent does not appear to add benefit. The use of dexmedetomidine to facilitate extubation in children intolerant of an awake, intubated state may abbreviate ventilator weaning. These data support a broader armamentarium of pediatric critical care sedation.

Effect of Noninvasive Ventilation Delivered by Helmet vs Face Mask on the Rate of Endoctrachael Intubation in Patients with Acute Respiratory Distress Syndrome: A Randomized Clinical Trial

Noninvasive ventilation with a face mask at preventing is relatively ineffective at preventing endotracheal intubation in patients with acute respiratory distress syndrome (ARDS).  Delivery of NIV with a helmet may be a superior strategy for these patients.  This RCT compared delivery by helmet vs face mask.  Amongst patients with ARDS, treatment with helmet NIV resulted in a significant reduction of intubation rates.  There was also a significant reduction in ninety day mortality with helmet NIV.

This trial was published in JAMA volume 315 number 22 14th June 2016.  It is available in print in the Healthcare Library on Level D of the hospital.  A full abstract and the full text for those with a personal subscription is available via this link.

Mechanical ventilation strategies for intensive care unit patients without acute lung injury or acute respiratory distress syndrome

Guo, L. et al. Critical Care. Published online: 22 July 2016.

Background: It has been shown that the application of a lung-protective mechanical ventilation strategy can improve the prognosis of patients with acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). However, the optimal mechanical ventilation strategy for intensive care unit (ICU) patients without ALI or ARDS is uncertain. Therefore, we performed a network meta-analysis to identify the optimal mechanical ventilation strategy for these patients.

Methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, EMBASE, MEDLINE, CINAHL, and Web of Science for studies published up to July 2015 in which pulmonary compliance or the partial pressure of arterial oxygen/fraction of inspired oxygen (PaO2/FIO2) ratio was assessed in ICU patients without ALI or ARDS, who received mechanical ventilation via different strategies. The data for study characteristics, methods, and outcomes were extracted. We assessed the studies for eligibility, extracted the data, pooled the data, and used a Bayesian fixed-effects model to combine direct comparisons with indirect evidence.

Results: Seventeen randomized controlled trials including a total of 575 patients who received one of six ventilation strategies were included for network meta-analysis. Among ICU patients without ALI or ARDS, strategy C (lower tidal volume (VT) + higher positive end-expiratory pressure (PEEP)) resulted in the highest PaO2/FIO2 ratio; strategy B (higher VT + lower PEEP) was associated with the highest pulmonary compliance; strategy A (lower VT + lower PEEP) was associated with a shorter length of ICU stay; and strategy D (lower VT + zero end-expiratory pressure (ZEEP)) was associated with the lowest PaO2/FiO2 ratio and pulmonary compliance.

Conclusions: For ICU patients without ALI or ARDS, strategy C (lower VT + higher PEEP) was associated with the highest PaO2/FiO2 ratio. Strategy B (higher VT + lower PEEP) was superior to the other strategies in improving pulmonary compliance. Strategy A (lower VT + lower PEEP) was associated with a shorter length of ICU stay, whereas strategy D (lower VT + ZEEP) was associated with the lowest PaO2/FiO2 ratio and pulmonary compliance.

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Prevention of ventilator-associated pneumonia: Use of the care bundle approach

Alcan, A.O. et al. American Journal of Infection Control. Published online: 4 July 2016

Highlights

  • Ventilator-associated pneumonia is one of the most common nosocomial infections for critical care patients.
  • This study investigates the effect of using the care bundle on ventilator-associated pneumonia rates.
  • Implementation of the care bundle through nurse education is effective at reducing the rate of ventilator-associated pneumonia.

Image shows colour enhanced scanning electron micrograph of a colony of Streptococcus pneumoniae

Background: The ventilator-associated pneumonia (VAP) care bundle consists of evidence-based practices to improve the outcomes of patients receiving mechanical ventilatory therapy. This study aimed to investigate the implementation of the care bundle on VAP rates in this quasiexperimental study.

Methods: The protocol of this study consisted of 3 phases. In the initial phase, observations were made to determine the VAP care bundle adherence of intensive care unit (ICU) nurses. In the second phase, education was provided to ICU nurses on the subject of the VAP care bundle. For the third phase, the effect of VAP care bundle adherence on the VAP rates after education was investigated.

Results: The nurses’ VAP care bundle adherence improved after education from 10.8% (n = 152) to 89.8% (n = 1,324) and showed statistically significant improvement (P = .0001 and P < .05). In this study, the VAP rates were determined as 15.91/103 ventilator-days before education and 8.50/103 ventilator days after education. It was found that the VAP rates after the education period were significantly lower than the VAP rates before education.

Conclusion: VAP care bundle implementation with education prepared according to evidence-based guidelines decreased VAP rates. Thus, implementation of the VAP care bundle on mechanically ventilated patients care is recommended.

Read the abstract here