Effects of Different Lung Lavage Solutions on Lung Injury

Aim: Experimental animal studies showed that lactated Ringer solution have beneficial effects over isotonic saline solution (0.9% NaCl) for mucociliar activity and clearance of upper respiratory tract. In this study we evaluated the effect of lactated Ringer solution and isotonic saline solution on rat lungs for lung injury. Material and Method: Istanbul University, Istanbul Medical Faculty, Experimental Animal Researches Study Institute ethical committee approval was obtained for 24 Sprague-Dawley rats each weighing between 250-300 g. Rats were tracheostomized under general anesthesia and ventilated using pressure controlled ventilation mode. As the first part of our study, we aimed to find the adequate lavage volume of isotonic saline and lactated Ringer solutions to induce ARDS. After finding the adequate lavage volume and count; the mean lavage count that induce ARDS, rest of the rats were randomly divided into two groups and tracheal lavages were performed according to predetermined lavage volume and count in the second part of the study. Wet/dry body weight counts, arterial blood gas sampling and microalbumin levels of bronchoalveolar lavage were analyzed for assessment of lung injury. Results: ARDS was developed following 11.4 lavages with isotonic saline solution and 10.57 lavages with lactated Ringer solutions. In the second part of the study, wet/dry body weight and BAL microalbumin levels were found lower in isotonic saline group however the difference between groups were not statistically significant. Conclusion: We were not able to demonstrate the superiority of using lactated Ringer solution over isotonic saline in terms of lung injury when used for lung lavage in rats. (Journal of the Turkish Society Intensive Care 2011; 9:48-52

Geoeconomic variations in epidemiology, ventilation management, and outcomes in invasively ventilated intensive care unit patients without acute respiratory distress syndrome: a pooled analysis of four observational studies

Background: Geoeconomic variations in epidemiology, the practice of ventilation, and outcome in invasively ventilated intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) remain unexplored. In this analysis we aim to address these gaps using individual patient data of four large observational studies. Methods: In this pooled analysis we harmonised individual patient data from the ERICC, LUNG SAFE, PRoVENT, and PRoVENT-iMiC prospective observational studies, which were conducted from June, 2011, to December, 2018, in 534 ICUs in 54 countries. We used the 2016 World Bank classification to define two geoeconomic regions: middle-income countries (MICs) and high-income countries (HICs). ARDS was defined according to the Berlin criteria. Descriptive statistics were used to compare patients in MICs versus HICs. The primary outcome was the use of low tidal volume ventilation (LTVV) for the first 3 days of mechanical ventilation. Secondary outcomes were key ventilation parameters (tidal volume size, positive end-expiratory pressure, fraction of inspired oxygen, peak pressure, plateau pressure, driving pressure, and respiratory rate), patient characteristics, the risk for and actual development of acute respiratory distress syndrome after the first day of ventilation, duration of ventilation, ICU length of stay, and ICU mortality. Findings: Of the 7608 patients included in the original studies, this analysis included 3852 patients without ARDS, of whom 2345 were from MICs and 1507 were from HICs. Patients in MICs were younger, shorter and with a slightly lower body-mass index, more often had diabetes and active cancer, but less often chronic obstructive pulmonary disease and heart failure than patients from HICs. Sequential organ failure assessment scores were similar in MICs and HICs. Use of LTVV in MICs and HICs was comparable (42·4% vs 44·2%; absolute difference -1·69 [-9·58 to 6·11] p=0·67; data available in 3174 [82%] of 3852 patients). The median applied positive end expiratory pressure was lower in MICs than in HICs (5 [IQR 5-8] vs 6 [5-8] cm H2O; p=0·0011). ICU mortality was higher in MICs than in HICs (30·5% vs 19·9%; p=0·0004; adjusted effect 16·41% [95% CI 9·52-23·52]; p<0·0001) and was inversely associated with gross domestic product (adjusted odds ratio for a US$10 000 increase per capita 0·80 [95% CI 0·75-0·86]; p<0·0001). Interpretation: Despite similar disease severity and ventilation management, ICU mortality in patients without ARDS is higher in MICs than in HICs, with a strong association with country-level economic status