Low Tidal Volume Strategy Research Articles

Acute Respiratory Distress Syndrome Due To Tuberculosis in a Respiratory ICU Over a 16-Year Period.

Whether tuberculosis-related acute respiratory distress syndrome is associated with worse outcomes when compared with acute respiratory distress syndrome secondary to other causes remains unknown. Herein, we compare the outcomes between the two groups. Retrospective analysis of all subjects admitted with acute respiratory distress syndrome over the last 16 years. Respiratory ICU of a tertiary care hospital in North India. Consecutive subjects with acute respiratory distress syndrome. Subjects were categorized as tuberculosis-related acute respiratory distress syndrome and acute respiratory distress syndrome-others and were managed with mechanical ventilation using the low tidal volume strategy as per the Acute Respiratory Distress Syndrom Network protocol. The baseline clinical and demographic characteristics, lung mechanics, and mortality were compared between the two groups. Factors predicting ICU survival were analyzed using multivariate logistic regression analysis. During the study period, 469 patients (18 tuberculosis-related acute respiratory distress syndrome and 451 acute respiratory distress syndrome-others) with acute respiratory distress syndrome were admitted. The mean (SD) age of the study population (52.9% women) was 33.6 years (14.8 yr). The baseline parameters and the lung mechanics were similar between the two groups. There were 132 deaths (28.1%) with no difference between the two groups (tuberculosis-related acute respiratory distress syndrome vs acute respiratory distress syndrome-others; 27.7% vs 28.2%; p = 0.71). There was also no significant difference in the ventilator-free days, ICU, and the hospital length of stay. On multivariate logistic regression analysis, the factors predicting survival were the admission Acute Physiology and Chronic Health Evaluation II score and baseline driving pressure after adjusting for PaO2:FIO2 ratio, gender, and the etiology of acute respiratory distress syndrome. Tuberculosis is an uncommon cause of acute respiratory distress syndrome even in high tuberculosis prevalence countries. Acute respiratory distress syndrome due to tuberculosis behaves like acute respiratory distress syndrome due to other causes and does not affect the ICU survival.

Intraoperative low tidal volume ventilation strategy has no benefits during laparoscopic cholecystectomy

Background and Aims:Benefits of intraoperative low tidal volume ventilation during laparoscopic surgery are not conclusively proven, even though its advantages were seen in other situations with intraoperative respiratory compromise such as one-lung ventilation. The present study compared the efficacy of intraoperative low tidal volume ventilatory strategy (6 ml/kg along with positive end-expiratory pressure [PEEP] of 10 cmH2O) versus one with higher tidal volume (10 ml/kg with no PEEP) on various clinical parameters and plasma levels of interleukin (IL)-6 in patients undergoing laparoscopic cholecystectomy.Material and Methods:A total of 58 adult patients with American Society of Anesthesiologists physical status I or II, undergoing laparoscopic cholecystectomy were randomized to receive the low or higher tidal volume strategy as above (n = 29 each). The primary outcome measure was postoperative PaO2. Systemic levels of IL-6 along with clinical indices of intraoperative gas exchange, pulmonary mechanics, and hemodynamic consequences were measured as secondary outcome measures.Results:There was no statistically significant difference in oxygenation; intraoperative dynamic compliance, peak airway pressures, or hemodynamic parameters, or the IL-6 levels between the two groups (P > 0.05). Low tidal volume strategy was associated with significantly higher mean airway pressure, lower airway resistance, greater respiratory rates, and albeit clinically similar, higher PaCO2and lower pH (P < 0.05).Conclusion:Strategy using 6 ml/kg tidal volume along with 10 cmH2O of PEEP was not associated with any significant improvement in gas exchange, hemodynamic parameters, or systemic inflammatory response over ventilation with 10 ml/kg volume without PEEP during laparoscopic cholecystectomy.

Acute Respiratory Distress Syndrome.

Acute respiratory distress syndrome (ARDS) is a serious inflammatory disorder with high mortality. Its main pathologic mechanism seems to result from increased alveolar permeability. Its definition has also changed since first being described according to the Berlin definition, which now classifies ARDS on a severity scale based on PaO2 (partial pressure of oxygen, arterial)/FIO2 (fraction of inspired oxygen) ratio. The cornerstone of therapy was found to be a low tidal volume strategy featuring volumes of 6 to 8 mL per kg of ideal body weight that has been shown to have decreased mortality as proven by the ARDSnet trials. There are other areas of treatment right now that include extracorporeal membrane oxygenation, as well for severe refractory hypoxemia. Other methods that include prone positioning for ventilation have also shown improvements in oxygenation. Positive end-expiratory pressure with lung recruitment maneuvers has also been found to be helpful. Other therapies that include vasodilators and neuromuscular agents are still being explored and need further studies to define their role in ARDS.

Noninvasive ventilation in acute respiratory distress syndrome: A long way ahead.

Sir, We thank Rao et al. for their observation on our study [1] regarding the use of noninvasive ventilation (NIV) in mild-to-moderate acute respiratory distress syndrome (ARDS).[2] The response from Rao and Munta presents a very gloomy picture for the role of NIV in ARDS, which is not true.[2] The judicious use of NIV has been shown to prevent endotracheal intubation in 52% of the cases of ARDS.[3] The mortality rate in studies involving the use of NIV in ARDS is variable, depending on the patient profile.[3] While it was 32% in the study (Thille et al.)[4] quoted by Rao et al., it has been reported to be as high as 71%.[5] The authors have raised a concern regarding a delay in intubation being the primary reason for high mortality. They further suggest that earlier intubation could have avoided the deaths in our study.[1] The median (interquartile range) time to intubation was 3 (1–4) h in our study that is far earlier than that reported in an international multicenter study on the use of NIV in ARDS.[6] Further, without a control group of invasive ventilation, one cannot conclude from our study that the use of NIV or delay in intubation led to an increase in mortality. In addition, Rao et al. quote a retrospective study (a study design fraught with many limitations) describing the use of NIV in ARDS following esophagectomy (postsurgical patients),[7] the patient profile being entirely different from that of our study (predominantly sepsis). Interestingly, Rao et al. claim an astonishingly low mortality rate of ARDS in their Intensive Care Unit (ICU) using pressure control ventilation (a strategy yet to establish its role in ARDS).[2] Only two strategies have shown a reduction in mortality in patients with ARDS, namely the low tidal volume strategy using volume control ventilation and prone ventilation.[8,9] The mortality even at best centers has been reported to be around 32%.[8] Further, the reference by the authors where they suggest a low mortality in their ICU seems to be a review article and not an original article subjected to the rigors of a thorough peer review.[10] It would be interesting to see if Rao et al. could replicate their observation in an original article. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

PReVENT--protective ventilation in patients without ARDS at start of ventilation: study protocol for a randomized controlled trial.

BackgroundIt is uncertain whether lung-protective mechanical ventilation using low tidal volumes should be used in all critically ill patients, irrespective of the presence of the acute respiratory distress syndrome (ARDS). A low tidal volume strategy includes use of higher respiratory rates, which could be associated with increased sedation needs, a higher incidence of delirium, and an increased risk of patient-ventilator asynchrony and ICU-acquired weakness. Another alleged side-effect of low tidal volume ventilation is the risk of atelectasis. All of these could offset the beneficial effects of low tidal volume ventilation as found in patients with ARDS.Methods/DesignPReVENT is a national multicenter randomized controlled trial in invasively ventilated ICU patients without ARDS with an anticipated duration of ventilation of longer than 24 hours in 5 ICUs in The Netherlands. Consecutive patients are randomly assigned to a low tidal volume strategy using tidal volumes from 4 to 6 ml/kg predicted body weight (PBW) or a high tidal volume ventilation strategy using tidal volumes from 8 to 10 ml/kg PBW. The primary endpoint is the number of ventilator-free days and alive at day 28. Secondary endpoints include ICU and hospital length of stay (LOS), ICU and hospital mortality, the incidence of pulmonary complications, including ARDS, pneumonia, atelectasis, and pneumothorax, the cumulative use and duration of sedatives and neuromuscular blocking agents, incidence of ICU delirium, and the need for decreasing of instrumental dead space.DiscussionPReVENT is the first randomized controlled trial comparing a low tidal volume strategy with a high tidal volume strategy, in patients without ARDS at onset of ventilation, that recruits a sufficient number of patients to test the hypothesis that a low tidal volume strategy benefits patients without ARDS with regard to a clinically relevant endpoint.Trial registrationThe trial is registered at www.clinicaltrials.gov under reference number NCT02153294 on 23 May 2014.

Limiting volume with modern ventilators.

The acute respiratory distress syndrome (ARDS) network low tidal-volume study comparing tidal volumes of 12 ml/kg versus 6 ml/kg was published in 2000. The study was stopped early as data revealed a 22% relative reduction in mortality rate when using 6 ml/kg tidal volume. The current generation of critical care ventilators allows the tidal volume to be set during volume-targeted, assist/control (volume A/C); however, some ventilators include options that may prevent the tidal volume from being controlled. The purpose of this bench study was to evaluate the delivered tidal volume, when these options are active, in a spontaneously breathing lung model using an electronic breathing simulator. Four ventilators were evaluated: CareFusion AVEA (AVEA), Dräger Evita® XL (Evita XL), Covidien Puritan Bennett® 840(TM) (PB 840), and Maquet SERVO-i (SERVO-i). Each ventilator was connected to the Hans Rudolph Electronic Breathing Simulator at an amplitude of 0 cm H2O and then 10 cm H2O. All four ventilators were set to deliver volume A/C, tidal volume 400 ml, respiratory rate 20 bpm, positive end-expiratory pressure 5 cm H2O, peak flowrate 60 L/min. The displayed tidal volume was recorded for each ventilator at the above settings with additional options OFF and then ON. The AVEA has two options in volume A/C: demand breaths and V-sync. When activated, these options allow the patient to exceed the set tidal volume. When using the Evita XL, the option AutoFlow can be turned ON or OFF, and when this option is ON, the tidal volume may vary. The PB 840 does not have any additional options that affect volume delivery, and it maintains the set tidal volume regardless of patient effort. The SERVO-i's demand valve allows additional flow if the patient's inspiratory flowrate exceeds the set flowrate, increasing the delivered tidal volume; this option can be turned OFF with the latest software upgrade. Modern ventilators have an increasing number of optional settings. These settings may increase the delivered tidal volume and disrupt a low tidal-volume strategy. Recognizing how each setting within a mode affects the type of breath delivered is critical when caring for ventilator-dependent patients.

A ventilator strategy combining low tidal volume ventilation, recruitment maneuvers, and high positive end-expiratory pressure does not increase sedative, opioid, or neuromuscular blocker use in adults with acute respiratory distress syndrome and may improve patient comfort.

BackgroundThe Lung Open Ventilation Study (LOV Study) compared a low tidal volume strategy with an experimental strategy combining low tidal volume, lung recruitment maneuvers, and higher plateau and positive end-expiratory pressures (PEEP) in adults with acute respiratory distress syndrome (ARDS). Herein, we compared sedative, opioid, and neuromuscular blocker (NMB) use among patients managed with the intervention and control strategies and clinicians' assessment of comfort in both groups.MethodsThis was an observational substudy of the LOV Study, a randomized trial conducted in 30 intensive care units in Canada, Australia, and Saudi Arabia. In 16 centers, we recorded daily doses of sedatives, opioids, and NMBs and surveyed bedside clinicians about their own comfort with the assigned ventilator strategy and their perceptions of patient comfort. We compared characteristics and outcomes of patients who did and did not receive NMBs.ResultsStudy groups received similar sedative, opioid, and NMB dosing on days 1, 3, and 7. Patient comfort as assessed by clinicians was not different in the two groups: 93% perceived patients had no/minimal discomfort. In addition, 92% of clinicians were comfortable with the assigned ventilation strategy without significant differences between the two groups. When clinicians expressed discomfort, more expressed discomfort about PEEP levels in the intervention vs control group (2.9% vs 0.7%, P <0.0001), and more perceived patient discomfort among controls (6.0% vs 4.3%, P = 0.049). On multivariable analysis, the strongest associations with NMB use were higher plateau pressure (hazard ratio (HR) 1.15; 95% confidence interval (CI) 1.07 to 1.23; P = 0.0002) and higher daily sedative dose (HR 1.03; 95% CI 1.02 to 1.05; P <0.0001). Patients receiving NMBs had more barotrauma, longer durations of mechanical ventilation and hospital stay, and higher mortality.ConclusionsIn the LOV Study, high PEEP, low tidal volume ventilation did not increase sedative, opioid, or NMB doses in adults with ARDS, compared with a lower PEEP strategy, and appeared at least as comfortable for patients. NMB use may reflect worse lung injury, as these patients had more barotrauma, longer durations of ventilation, and higher mortality.Trial registrationClinicalTrials.gov Identifier NCT00182195

Detection of Fibroproliferation by Chest High-Resolution CT Scan in Resolving ARDS

In ARDS, the extent of fibroproliferative activity on chest high-resolution CT (HRCT) scan has been reported to correlate with poorer short-term outcomes and pulmonary-associated quality of life. However, clinical factors associated with HRCT scan fibroproliferation are incompletely characterized. We questioned if lung compliance assessed at the bedside would be associated with fibroproliferation on HRCT scans obtained during the resolution phase of ARDS. We used data from a published randomized, controlled clinical trial in ARDS. All patients were cared for using a low tidal volume strategy. Demographic data and ventilator parameters were examined in association with radiologic scores from chest HRCT scans obtained 14 days after diagnosis. Data from 82 patients with ARDS were analyzed. Average static respiratory compliance over the first 14 days after diagnosis was inversely associated with chest HRCT scan reticulation (ρ = -0.46); this relationship persisted in multivariable analysis including APACHE (Acute Physiology and Chronic Health Evaluation) II scores, initial Pao2/Fio2, pneumonia diagnosis, and ventilator days. Average static respiratory compliance was also lower among patients with bronchiectasis at day 14 (P = .007). Initial static respiratory compliance obtained within the first day after ARDS diagnosis was correlated inversely with the presence of HRCT scan reticulation (ρ = -0.38) and was lower among patients who demonstrated bronchiectasis on the day 14 HRCT scan (P = .008). In patients with ARDS, diminished lung compliance measured bedside was associated with radiologic fibroproliferation 14 days post diagnosis. Establishing factors that predispose to development of excessive fibroproliferation with subsequent confirmation by chest HRCT scan represents a promising strategy to identify patients with ARDS at risk for poorer clinical outcomes.

Evaluation of the cardiopulmonary status using a noninvasive respiratory profile monitor in chronic obstructive lung disease patients during low-ventilation strategy

Patients with chronic obstructive pulmonary disease (COPD) patients are susceptible to complications, especially volutrauma, during the period of mechanical ventilation; low ventilation is a safe strategy to avoid these complications. Noninvasive capnography is a suitable technique for monitoring and assessing the cardiac and the pulmonary status of these patients during the period of mechanical ventilation. Assessment of the cardiac and the pulmonary status of two COPD patient groups receiving mechanical ventilation with a low tidal volume strategy using a noninvasive CO2 respiratory profile monitor (volumetric capnography). Forty patients were recruited in the respiratory ICU of Abbassia Chest Hospital; these patients were divided into two groups: 20 COPD patients with the predominant pathology of chronic bronchitis (CB) and 20 patients with the predominant pathology of emphysema disease, who presented with clinical and radiological evidence of chronic obstructive lung disease and were in need of mechanical ventilation. All the patients in the study were followed up three times per day until weaning; data were recorded on admission, after 24 h and before weaning using volumetric capnography. There was significant correlation between EtCO2 and arterial PCO2 during the whole period of mechanical ventilation in CB and emphysematous patients; the mean dead-space fraction was significantly higher in the emphysema group than in the CB group. There was a significant negative correlation between the mean values of Vd/Vt and the pulmonary capillary blood flow on admission and after 24 h in the emphysema group. The mean cardiac output, the mean stroke volume, and the pulmonary capillary blood flow increased significantly before extubation in the CB group, in contrast to the emphysema group in which there was an insignificant difference. Volumetric capnography could be helpful in assessing the severity of functional disturbances, and the use of more refined noninvasive parameters will be of value in managing and monitoring COPD patients during the whole period of mechanical ventilation. Egypt J Broncho 2014 8:44–50

Lung recruitment in acute respiratory distress syndrome

Supporting patients with acute respiratory distress syndrome (ARDS) using a low tidal volume strategy is a standard practice in the ICU. Recruitment maneuvers can be used to augment other methods, like positive end-expiratory pressure and positioning, to improve aerated lung volume. Clinical practice varies widely, and optimal method and patient selection for recruitment maneuvers have not been determined. Recent developments include experimental and clinical evidence that a stepwise extended recruitment maneuver may match the improvement in aerated lung volume seen with sustained inflation traditionally used, with less adverse effects. Positioning and other chest wall modifications may be useful adjuncts to recruitment maneuvers. In addition, evidence from clinical studies in the operating room suggests that recruitment maneuvers, as a component of an open lung strategy, may be helpful for mechanically ventilated patients with normal lungs. As a component of ventilation strategy for patients with ARDS, the use of recruitment maneuvers, especially a stepwise maneuver, in addition to adequate positive end-expiratory pressure and appropriate positioning, is suggested by currently available data. Until their effect on clinical outcomes is further defined, the use of recruitment maneuvers in ARDS and other settings will continue to be guided by individual clinician experience and patient factors.

Cardiac index and oxygen delivery during low and high tidal volume ventilation strategies in patients with acute respiratory distress syndrome: a crossover randomized clinical trial.

IntroductionThe beneficial effect of low tidal volume (TV) ventilation strategy on mortality in patients with acute respiratory distress syndrome (ARDS) has been attributed to the protective effect on ventilator-induced lung injury, and yet its effect on cardiovascular function might also play an important role. The aim of this study was to assess whether low TV ventilation improves cardiac output and oxygen delivery compared with high TV ventilation strategy in patients with ARDS.MethodsIn this crossover randomized clinical trial 16 ARDS patients were recruited in an intensive care unit at a university-affiliated hospital. Each patient was ventilated for 30 min with low (6 mL/kg) and 30 min with high (12 mL/kg) TV. The two experimental periods, applied in random order and with allocation concealment, were separated by 30 min of basal ventilation. Minute ventilation was constantly maintained by appropriate respiratory rate changes.ResultsCompared with high TV ventilation, low TV ventilation showed decreased pH (7.37 vs. 7.41, P = 0.001) and increased PaCO2 (49 vs. 43 mmHg; P = 0.002). Cardiac index and oxygen delivery index were increased with low compared with high TV ventilation (3.9 vs. 3.5 L.min-1.m-2, P = 0.012, and 521 vs. 463 mL.min-1.m-2, P = 0.002, respectively), while oxygen extraction ratio decreased (0.36 vs. 0.44, P = 0.027). In four patients oxygen extraction ratio was >0.5 during high TV but not during low TV strategy. The magnitude of the change in cardiac index was positively associated with PaCO2 variation (P = 0.004), while it was unrelated to the magnitude of changes in TV and airway pressure. The decrease of cardiac index was predicted by PaCO2 reduction, with and area under ROC curve of 0.72.ConclusionsOur findings suggest that a low TV ventilation strategy increases cardiac index and oxygen delivery, thus supporting the hypothesis that the beneficial effect of low TV ventilation in patients with ARDS could be partially explained by hemodynamic improvement. In other words, low tidal volume ventilation could be protective also for the cardiovascular system and not only for the lung. The slight increase of PaCO2 during low TV ventilation seems to predict the increase of cardiac index.Trial registrationClinicalTrials.gov: NCT00713713

Tele-ICU Ventilator Rounds Are Associated With Improved Adherence to Low Tidal Volume Strategy and Decreased Duration of Mechanical Ventilation

SESSION TYPE: Improving Processes and Outcomes in Adult Critical Care

The Introduction of Extracorporeal Membrane Oxygenation to Aeromedical Evacuation

To review the principles of extracorporeal membrane oxygenation (ECMO) and to describe the recent advancements in ECMO technology that permit use of this rescue therapy for severe lung injury in combat casualties. Lung protective ventilation has defined the state-of-the-art treatment for acute lung injury for more than a decade. Despite the benefits provided by a low tidal volume strategy, lung injury patients may experience deterioration in gas exchange to the point that other rescue interventions are needed or the patient succumbs to progressive respiratory failure. When this occurs in combat casualties, management of the patient in an austere environment and movement to definitive care become problematic. Recent advances in ECMO technology permit long-range transport of these critically ill casualties with greater physiologic reserve and potentially less mortality. Advances in ECMO technology now enable the stabilization and aeromedical evacuation of even the most critically ill combat casualties with severe lung injury.

Estimating the Causal Effect of Low Tidal Volume Ventilation on Survival in Patients with Acute Lung Injury.

Acute lung injury (ALI) is a condition characterized by acute onset of severe hypoxemia and bilateral pulmonary infiltrates. ALI patients typically require mechanical ventilation in an intensive care unit. Low tidal volume ventilation (LTVV), a time-varying dynamic treatment regime, has been recommended as an effective ventilation strategy. This recommendation was based on the results of the ARMA study, a randomized clinical trial designed to compare low vs. high tidal volume strategies (The Acute Respiratory Distress Syndrome Network, 2000) . After publication of the trial, some critics focused on the high non-adherence rates in the LTVV arm suggesting that non-adherence occurred because treating physicians felt that deviating from the prescribed regime would improve patient outcomes. In this paper, we seek to address this controversy by estimating the survival distribution in the counterfactual setting where all patients assigned to LTVV followed the regime. Inference is based on a fully Bayesian implementation of Robins' (1986) G-computation formula. In addition to re-analyzing data from the ARMA trial, we also apply our methodology to data from a subsequent trial (ALVEOLI), which implemented the LTVV regime in both of its study arms and also suffered from non-adherence.

Intraoperative adherence to a low tidal volume ventilation strategy in critically ill patients with preexisting acute lung injury

Purpose Low tidal volume (LTV) ventilation reduces mortality in patients with acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). This study investigates adherence of intraoperative LTV and whether patient outcomes were different with or without continued intraoperative LTV ventilation in patients with previously established ALI or ARDS. Materials and Methods A retrospective analysis was performed of adults with ALI/ARDS over a 2-year period who underwent surgery between 24 hours and 14 days after the diagnosis of ALI/ARDS. The main outcome was intraoperative LTV use. Secondary outcomes included perioperative respiratory and clinical outcomes. Results Of the 249 patients who underwent surgery between 24 hours and 14 days after ALI/ARDS diagnosis, 101 (41%) received preoperative LTV ventilation. Fifty-four (53%) received intraoperative LTV ventilation, whereas 47 (47%) did not. Use of preoperative LTV ventilation was associated with use of intraoperative LTV ventilation ( P < .01). No differences in respiratory or clinical outcomes between patients with or without intraoperative LTV ventilation were observed. Conclusions Adherence to intraoperative LTV in surgical patients was low. Adherence of LTV intraoperatively was not associated with improved oxygenation, reductions in hospital length of stay, or in-hospital mortality. The importance of adhering to an intraoperative LTV strategy remains unclear.

Impact of acute kidney injury on lung injury

classic animal models of critical illness have focused on injury of a single end-organ, with the goal of better understanding and attenuating that injury, and ultimately developing novel disease-focused therapies. For example, acute lung injury (ALI) can be induced in animal models by administration

Ventilator-associated lung injury: a search for better therapeutic targets

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) represent a continuum of injury that may arise from a number of primary insults. Localised injury may progress due to trauma from mechanical ventilation, a finding that has led to intense debate in the clinical and experimental literature over optimal ventilator management. The implementation of low tidal volume strategies has led to an improvement in outcomes; however, mortality remains unacceptably high. In the current review, ventilator-associated lung injury is examined, as it relates to the pathophysiological changes beyond direct airway trauma in ALI and ARDS, and an attempt is made to provide a historical perspective to outline potential current and future pitfalls in the use of surrogate end-points and the discovery of potential biomarkers. The systemic responses that lead to multi-organ dysfunction, the leading causes of morbidity and mortality in ALI and ARDS, are caused by pro-inflammatory signalling cascades and the activation of such diverse mediators as reactive oxygen species, immune response elements, apoptotic constituents and coagulation proteins. These areas are examined, including key mediators, and possible future areas of interest are discussed, including the potential of an "acute lung injury chip" to integrate measured surrogate biomarkers with real-time clinical information to improve patient outcomes.

Selective medicated (normal saline and exogenous surfactant) bronchoalveolar lavage in severe aspiration syndrome in children*

To study the ability of volume-controlled ventilation and medicated (normal saline plus surfactant) bronchoalveolar lavage in aspiration to reduce the duration of intubation and improve gas exchange. : Randomized controlled clinical trial. Pediatric intensive care unit. Twenty children, 1 month to 16 yrs old, who were intubated and mechanically ventilated, were randomized within 6 hrs of aspiration to receive volume-controlled ventilation plus medicated bronchoalveolar lavage (treatment group) or the same ventilation and bronchosuction (control group). Volume-controlled ventilation and positive end-expiratory pressure (10-12 cm H2O) were applied. Medicated bronchoalveolar lavage was performed using five aliquots of 5 mL of saline plus 10 mg/mL Curosurf (porcine surfactant, Chiesi Pharmaceutical SpA, Parma, Italy) in infants, five boluses of 10 mL of saline plus 5 mg/mL Curosurf in children, and four boluses of 25 mL of saline with 2.4 mg/mL Curosurf in adolescents for each affected lobe. One hour after bronchoalveolar lavage, 240 mg of Curosurf was administered locally. All patients survived. In the treatment group, days of intubation were 4.6 (+/-1.07), oxygenation index and Pao2/Fio2 improved significantly at 24 hrs, and statistical reduction in tidal volume mL/kg was observed from 36 hrs. In the control group, days of intubation were 11.8 (+/-3.22) (p < .0001), no improvement in oxygenation was noted, and pneumonia was observed in seven children (70%). Even though this was an unblinded small clinical trial and low tidal volume strategy was not employed at an early stage after lung injury, there is some evidence that bronchoalveolar lavage with normal saline and surfactant may have clinical value in treating severe aspiration syndrome in children. More clinical studies are warranted to overcome study limitations and potential bias.

A Case of Severe Acute Respiratory Distress Syndrome Treated with Extracorporeal Life Support

The incidence of acute respiratory distress syndrome (ARDS) has been estimated worldwide to range from 1.7 to 75 cases per 100,000. There are many treatments for ARDS, but only the low tidal volume strategy is based on strong clinical evidence from randomized clinical trials. The efficacy of extracorporeal life support (ECLS) in adults remains controversial. Ongoing clinical trials and research have shown a benefit for its use to salvage severe ARDS patients that are in failure with conventional treatment. We encountered a 41-year-old woman who developed ARDS induced by pneumococcal pneumonia. Despite conventional mechanical ventilation in the emergency room, severe hypoxia remained. We treated the patient immediately with ECLS. The patient has almost fully recovered, and was discharged from a 177-day stay at our hospital.

Evolving Practices in Critical Care and Potential Implications for Management of Acute Kidney Injury

Acute kidney injury (AKI) is a common complication in hospitalized patients, with an incidence of 3 to 10% (1–4). In-hospital mortality rates that are associated with AKI remain high, in the range of 30 to 70% (5–8), despite significant improvements in dialytic technology as well as important advances in critical care, which have resulted in improved survival for other critical illnesses, including acute lung injury and sepsis (9). These improvements include continuous renal replacement therapies, which allow for continuous removal of solutes and fluid and may be tolerated better from a hemodynamic standpoint, and biocompatible dialysis membranes, which are associated with reduced complement and granulocyte activation. In general, indications for dialysis in the acute care setting have been extrapolated from those that are applied in chronic kidney disease, including volume overload that is refractory to diuretic therapy; electrolyte abnormalities (in particular hyperkalemia); uremic complications (pericarditis or pleuritis); severe acidosis (pH < 7.20); and selected toxic ingestions, such as methanol, ethylene glycol, and other water-soluble agents (10,11). However, the evidence base supporting specific dialysis practices in the acute care setting is limited. For example, several studies that were completed in the 1960s and 1970s compared “early” and “late” initiation of dialysis, using blood urea nitrogen (BUN) to define early and late (Table 1). These studies primarily were cohort studies that used historical controls, not randomized, clinical trials. The results of these investigations, along with extrapolation from the ESRD population, promoted recent practice patterns. Currently, many nephrologists often delay dialysis in the acute care setting until the patient has an impending complication of AKI, such as hyperkalemia leading to cardiac arrhythmias, acidosis resulting in hypotension, or oliguria leading to volume overload or hypoxemia, or until the BUN exceeds 100 mg/dl (18). Given differences in protein catabolism, …