An Index Combining Respiratory Rate and Oxygenation to Predict Outcome of Nasal High-Flow Therapy.

Rationale: One important concern during high-flow nasal cannula (HFNC) therapy in patients with acute hypoxemic respiratory failure is to not delay intubation. Objectives: To validate the diagnostic accuracy of an index (termed ROX and defined as the ratio of oxygen saturation as measured by pulse oximetry/FiO2 to respiratory rate) for determining HFNC outcome (need or not for intubation). Methods: This was a 2-year multicenter prospective observational cohort study including patients with pneumonia treated with HFNC. Identification was through Cox proportional hazards modeling of ROX association with HFNC outcome. The most specific cutoff of the ROX index to predict HFNC failure and success was assessed. Measurements and Main Results: Among the 191 patients treated with HFNC in the validation cohort, 68 (35.6%) required intubation. The prediction accuracy of the ROX index increased over time (area under the receiver operating characteristic curve: 2 h, 0.679; 6 h, 0.703; 12 h, 0.759). ROX greater than or equal to 4.88 measured at 2 (hazard ratio, 0.434; 95% confidence interval, 0.264-0.715; P = 0.001), 6 (hazard ratio, 0.304; 95% confidence interval, 0.182-0.509; P < 0.001), or 12 hours (hazard ratio, 0.291; 95% confidence interval, 0.161-0.524; P < 0.001) after HFNC initiation was consistently associated with a lower risk for intubation. A ROX less than 2.85, less than 3.47, and less than 3.85 at 2, 6, and 12 hours of HFNC initiation, respectively, were predictors of HFNC failure. Patients who failed presented a lower increase in the values of the ROX index over the 12 hours. Among components of the index, oxygen saturation as measured by pulse oximetry/FiO2 had a greater weight than respiratory rate. Conclusions: In patients with pneumonia with acute respiratory failure treated with HFNC, ROX is an index that can help identify those patients with low and those with high risk for intubation. Clinical trial registered with www.clinicaltrials.gov (NCT02845128).

Ventilator-associated respiratory infection following lung transplantation.

The medical records of 170 adult patients who underwent lung transplantation between January 2010 and December 2012 were reviewed to assess the incidence, causative organisms, risk factors and outcomes of post-operative pneumonia and tracheobronchitis. 20 (12%) patients suffered 24 episodes of ventilator-associated pneumonia. The condition was associated with mean increases of 43 days in mechanical ventilation and of 35 days in hospital stay, and significantly higher hospital mortality (OR 9.0, 95% CI 3.2-25.1). Pseudomonas aeruginosa (eight out of 12 patients were multidrug-resistant) was the most common pathogen, followed by Enterobacteriaceae (one out of five patients produced extended-spectrum ß-lactamases). Gastroparesis occurred in 55 (32%) patients and was significantly associated with pneumonia (OR 6.2, 95% CI 2.2-17.2). Ventilator-associated tracheobronchitis was associated with a mean increase of 28 days in mechanical ventilation and 30.5 days in hospital stay, but was not associated with higher mortality (OR 1.2, 95% CI 0.4-3.2). Pseudomonas aeruginosa (six out of 16 patients were multidrug resistant) was the most common pathogen, followed by Enterobacteriaceae (three out of 14 patients produced extended-spectrum ß-lactamase). Patients with gastroparesis also had more episodes of ventilator-associated tracheobronchitis (40% versus 12%, p<0.001). In conclusion, ventilator-associated pneumonia following lung transplantation increased mortality. Preventing gastroparesis probably decreases the risk of pneumonia and tracheobronchitis. Multidrug-resistant bacteria frequently cause post-lung-transplantation pneumonia and tracheobronchitis.

Ventilator-associated pneumonia management in critical illness.

PURPOSE OF REVIEW: Ventilator-associated pneumonia (VAP) is a frequent adverse event in the intensive care unit.We review recent publications about the management and prevention of VAP. RECENT FINDINGS: The latest care bundles introduced standard interventions to facilitate implementation of evidence-based clinical guidelines and to improve the outcome of patients. Recent studies find that prevention management of ventilated patients decreases the risk of VAP. Enteral feeding, considered a risk factor for VAP, currently has been recommended, with appropriate administration, for all critical ill patients if no contraindications exist. SUMMARY: In view of the recently available data, it can be concluded that the implementation of care bundles on the general management of ventilated patients in daily practice has reduced the VAP rates. The main pharmacological measures to prevent VAP are proper hands hygiene, high nurse-to-patient ratio, avoid unnecessary transfer of ventilated patients, use of noninvasive mechanical ventilation, shortening weaning period, avoid the use of nasal intubation, prevent bio-film deposition in endotracheal tube, aspiration of subglottic secretions, maintenance of adequate pressure of endotracheal cuffs, avoid manipulation of ventilator circuits, semi-recumbent position and adequate enteral feeding.In addition, updated guidelines incorporate more comprehensive diagnostic protocols to the evidence-based management of VAP.

Predicting success of high-flow nasal cannula in pneumonia patients with hypoxemic respiratory failure: The utility of the ROX index.

PURPOSE: The purpose of the study is to describe early predictors and to develop a prediction tool that accurately identifies the need for mechanical ventilation (MV) in pneumonia patients with hypoxemic acute respiratory failure (ARF) treated with high-flow nasal cannula (HFNC). MATERIALS AND METHODS: This is a 4-year prospective observational 2-center cohort study including patients with severe pneumonia treated with HFNC. High-flow nasal cannula failure was defined as need for MV. ROX index was defined as the ratio of pulse oximetry/fraction of inspired oxygen to respiratory rate. RESULTS: One hundred fifty-seven patients were included, of whom 44 (28.0%) eventually required MV (HFNC failure). After 12 hours of HFNC treatment, the ROX index demonstrated the best prediction accuracy (area under the receiver operating characteristic curve 0.74 [95% confidence interval, 0.64-0.84]; P<.002). The best cutoff point for the ROX index was estimated to be 4.88. In the Cox proportional hazards model, a ROX index greater than or equal to 4.88 measured after 12 hours of HFNC was significantly associated with a lower risk for MV (hazard ratio, 0.273 [95% confidence interval, 0.121-0.618]; P=.002), even after adjusting for potential confounding. CONCLUSIONS: In patients with ARF and pneumonia, the ROX index can identify patients at low risk for HFNC failure in whom therapy can be continued after 12 hours.

Humidified high flow nasal cannula supportive therapy improves outcomes in lung transplant recipients readmitted to the intensive care unit because of acute respiratory failure.

BACKGROUND: The effectiveness of humidified high flow nasal cannula (HFNC) in lung transplant (LTx) recipients readmitted to intensive care unit (ICU) because of acute respiratory failure (ARF) has not been determined to date. METHODS: Retrospective analysis of a prospectively assessed cohort of LTx patients who were readmitted to ICU because of ARF over a 5-year period. Patients received conventional oxygen therapy (COT) or HFNC (Optiflow, Fisher & Paykel, New Zealand) supportive therapy according to the attending physician's criteria. Treatment failure was defined as the need for subsequent mechanical ventilation (MV). RESULTS: Thirty-seven LTx recipients required ICU readmission, with a total of 40 episodes (18 COT vs. 22 HFNC). At ICU admission, no differences in comorbidities, pulmonary function, or median sequential organ failure assessment (COT, 4 [interquartile range, 4-6] vs. HFNC, 4 [interquartile range, 4-7]; P = 0.51) were observed. Relative risk of MV in patients with COT was 1.50 (95% confidence interval [95% CI], 1.02-2.21). The absolute risk reduction for MV with HFNC was 29.8%, and the number of patients needed to treat to prevent one intubation with HFNC was 3. Multivariate analysis showed that HFNC therapy was the only variable at ICU admission associated with a decreased risk of MV (odds ratio, 0.11 [95% CI, 0.02-0.69]; P = 0.02). Moreover, nonventilated patients had an increased survival rate (20.7% vs. 100%; relative rate 4.83 [95% CI, 2.37-9.86]; P < 0.001). No adverse events were associated with HFNC use. CONCLUSION: HFNC O2 therapy is feasible and safe and may decrease the need for MV in LTx recipients readmitted to the ICU because of ARF.