Alan T. Aquilina

Noninvasive ventilation for prevention of post-extubation respiratory failure in obese patients

Current recommendations for management of obese patients post-extubation are based on clinical experience and expert opinions. It was hypothesised that the application of noninvasive ventilation (NIV) during the first 48 h after extubation in severely obese patients would reduce post-extubation failure and avert the need for reintubation. Following protocol-driven weaning trials, 62 consecutive severely obese patients (body mass index ≥35 kg·m-2) were assigned to NIV via nasal mask immediately post-extubation and compared with 62 historically matched controls who were treated with conventional therapy. The primary end-point was the incidence of respiratory failure in the first 48 h post-extubation. Compared with conventional therapy, the institution of NIV resulted in 16% (95% confidence interval 2.9–29.3%) absolute risk reduction in the rate of respiratory failure. There was a significant difference in the intensive care unit and lengths of hospital stay between the two groups. Subgroup analysis of hypercapnic patients showed reduced hospital mortality in the NIV group compared with the control group. In conclusion, noninvasive ventilation may be effective in averting respiratory failure in severely obese patients when applied during the first 48 h post-extubation. In selected patients with chronic hypercarbia, early application of noninvasive ventilation may confer a survival benefit.

Radiographic resolution of community-acquired bacterial pneumonia in the elderly

Objectives: To investigate the radiographic clearance of proven community‐acquired nontuberculous bacterial pneumonia in nonimmunocompromised older patients to provide working estimates of the rate of radiographic resolution as a function of the patient cumulative comorbidities, extent of initial radiographic involvement, functional status, and causative pathogens.

Colonization of Dental Plaques

STUDY OBJECTIVES Poor dental hygiene has been linked to respiratory pathogen colonization in residents of long-term care facilities. We sought to investigate the association between dental plaque (DP) colonization and lower respiratory tract infection in hospitalized institutionalized elders using molecular genotyping. METHODS We assessed the dental status of 49 critically ill residents of long-term care facilities requiring intensive care treatment. Plaque index scores and quantitative cultures of DPs were obtained on ICU admission. Protected BAL (PBAL) was performed on 14 patients who developed hospital-acquired pneumonia (HAP). Respiratory pathogens recovered from the PBAL fluid were compared genetically to those isolated from DPs by pulsed-field gel electrophoresis. MEASUREMENTS AND RESULTS Twenty-eight subjects (57%) had colonization of their DPs with aerobic pathogens. Staphylococcus aureus (45%) accounted for the majority of the isolates, followed by enteric Gram-negative bacilli (42%) and Pseudomonas aeruginosa (13%). The etiology of HAP was documented in 10 patients. Of the 13 isolates recovered from PBAL fluid, nine respiratory pathogens matched genetically those recovered from the corresponding DPs of eight patients. CONCLUSIONS These findings suggest that aerobic respiratory pathogens colonizing DPs may be an important reservoir for HAP in institutionalized elders. Future studies are needed to delineate whether daily oral hygiene in hospitalized elderly would reduce the risk of nosocomial pneumonia in this frail population.

Procoagulant and fibrinolytic activity in ventilator-associated pneumonia: impact of inadequate antimicrobial therapy

ObjectiveTo determine the homeostatic balance of patients with ventilator-associated pneumonia (VAP) with respect to the adequacy of antimicrobial therapy.Design and settingDescriptive observational study in a 12-bed medical intensive care unit in a university-affiliated hospital.PatientsTwenty-nine patients with VAP documented by quantitative culture of bronchoalveolar secretions and a control group of eight mechanically ventilated patients.MethodsSerial bronchoalveolar lavage fluid (BALF) samples were assayed for prothrombin activation fragment (F1+2), thrombin-antithrombin (TAT) complex, fibrinolytic activity, urokinase-type plasminogen activator (u-PA), and plasminogen activator inhibitor type 1 (PAI-1) on days 1, 4, and 7 after VAP onset.ResultsPathogens isolated from patients with inadequate empirical antimicrobial coverage included methicillin-resistant Staphylococcus aureus (n=2), Pseudomonas aeruginosa (n=4), and Acinetobacter baumannii (n=1). Compared to those who received adequate antibiotic therapy, TAT, F1+2, and PAI-1 levels increased while u-PA levels remained unchanged. Despite antibiotic adjustment on day 4, TAT levels remained elevated in those who lacked adequate antimicrobial coverage and were significantly correlated with PaO2/FIO2. The procoagulant activity was accompanied by a local depression of fibrinolytic capacity that was attributed mainly to increased BALF PAI-1 levels. Nonsurvivors showed significantly higher levels of TAT and PAI-1 than survivors. No significant correlation between the bacterial burden and the homeostatic derangements was documented.ConclusionsThe lung inflammatory response seems to promulgate a local procoagulant activity associated with hypoxemia in those with inadequate antibiotic therapy. The homeostatic derangement seems to be independent of the lung bacterial burden.

Validation of the Behavioral Risk Factor Surveillance System Sleep Questions.

STUDY OBJECTIVES leep problems may constitute a risk for health problems, including cardiovascular disease, depression, diabetes, poor work performance, and motor vehicle accidents. The primary purpose of this study was to assess the validity of the current Behavioral Risk Factor Surveillance System (BRFSS) sleep questions by establishing the sensitivity and specificity for detection of sleep/ wake disturbance. METHODS Repeated cross-sectional assessment of 300 community dwelling adults over the age of 18 who did not wear CPAP or oxygen during sleep. Reliability and validity testing of the BRFSS sleep questions was performed comparing to BFRSS responses to data from home sleep study, actigraphy for 14 days, Insomnia Severity Index, Epworth Sleepiness Scale, and PROMIS-57. RESULTS Only two of the five BRFSS sleep questions were found valid and reliable in determining total sleep time and excessive daytime sleepiness. CONCLUSIONS Refinement of the BRFSS questions is recommended.

Feasibility Testing of a Self-Management Program Book to Improve Adherence to PAP in Persons Newly Diagnosed With Sleep Apnea

ABSTRACT Objectives: To obtain feasibility data on a self-management program to improve adherence with positive airway pressure (PAP) in individuals with newly diagnosed obstructive sleep apnea. Methods: A mixed-methods design assessed program effectiveness and participants’ opinions on program ease-of-use. Structured interviews with the treatment group occurred one week and one month after initiation of PAP therapy. Results: Participants (n = 14) completing the study demonstrated 64% adherence versus 58% of the controls. Ease of use was demonstrated. Conclusions: The PAP self-management program demonstrated ease of use and was found somewhat effective in improving PAP adherence. Practice implications: The book was useful in assisting participants by validating information obtained from their providers and developing an understanding of the consequences of not using PAP.

NONINVASIVE VENTILATION FOR PREVENTION OF POSTEXTUBATION RESPIRATORY FAILURE IN OBESE PATIENTS.: 328

Current recommendations for management of obese patients post-extubation are based on clinical experience and expert opinions. It was hypothesised that the application of noninvasive ventilation (NIV) during the first 48 h after extubation in severely obese patients would reduce post-extubation failure and avert the need for reintubation. Following protocol-driven weaning trials, 62 consecutive severely obese patients (body mass index > or =35 kg x m(-2)) were assigned to NIV via nasal mask immediately post-extubation and compared with 62 historically matched controls who were treated with conventional therapy. The primary end-point was the incidence of respiratory failure in the first 48 h post-extubation. Compared with conventional therapy, the institution of NIV resulted in 16% (95% confidence interval 2.9-29.3%) absolute risk reduction in the rate of respiratory failure. There was a significant difference in the intensive care unit and lengths of hospital stay between the two groups. Subgroup analysis of hypercapnic patients showed reduced hospital mortality in the NIV group compared with the control group. In conclusion, noninvasive ventilation may be effective in averting respiratory failure in severely obese patients when applied during the first 48 h post-extubation. In selected patients with chronic hypercarbia, early application of noninvasive ventilation may confer a survival benefit.

High-frequency oscillation during simulated altitude exposure

Ventilatory requirements using high-frequency oscillation (HFO) during simulated altitude exposure were investigated in control dogs and animals with oleic acid-induced lung injury. FIO2 values of 0.21 and 1.0 were supplied by bias flow to the normal and injured dogs, respectively. After a control period, animals were exposed to a simulated altitude of 8,000 ft (barometric pressure 564 torr), followed by a second control period at ground level. Both experimental groups had similar values of PaCO2 at ground level and during exposure to reduced barometric pressure. The tidal volume necessary to maintain eucapnia was higher in oleic acid-injured animals compared with the control group; cardiac output and functional residual capacity were lower. The alveolar-arterial oxygen difference was substantially larger in the oleic acid group. Adequate gas exchange can be maintained with HFO during exposure to altitude provided that ventilation and inspired PO2 are not reduced below normobaric levels.