Recruitment Maneuver In Patients Research Articles

Effect of the alveolar recruitment maneuver during laparoscopic colorectal surgery on postoperative pulmonary complications: A randomized controlled trial.

Intraoperative lung-protective ventilation, including low tidal volume and positive end-expiratory pressure, reduces postoperative pulmonary complications. However, the effect and specific alveolar recruitment maneuver method are controversial. We investigated whether the intraoperative intermittent recruitment maneuver further reduced postoperative pulmonary complications while using a lung-protective ventilation strategy. Adult patients undergoing elective laparoscopic colorectal surgery were randomly allocated to the recruitment or control groups. Intraoperative ventilation was adjusted to maintain a tidal volume of 6-8 mL kg-1 and positive end-expiratory pressure of 5 cmH2O in both groups. The alveolar recruitment maneuver was applied at three time points (at the start and end of the pneumoperitoneum, and immediately before extubation) by maintaining a continuous pressure of 30 cmH2O for 30 s in the recruitment group. Clinical and radiological evidence of postoperative pulmonary complications was investigated within 7 days postoperatively. A total of 125 patients were included in the analysis. The overall incidence of postoperative pulmonary complications was not significantly different between the recruitment and control groups (28.1% vs. 31.1%, P = 0.711), while the mean ± standard deviation intraoperative peak inspiratory pressure was significantly lower in the recruitment group (10.7 ± 3.2 vs. 13.5 ± 3.0 cmH2O at the time of CO2 gas-out, P < 0.001; 9.8 ± 2.3 vs. 12.5 ± 3.0 cmH2O at the time of recovery, P < 0.001). The alveolar recruitment maneuver with a pressure of 30 cmH2O for 30 s did not further reduce postoperative pulmonary complications when a low tidal volume and 5 cmH2O positive end-expiratory pressure were applied to patients undergoing laparoscopic colorectal surgery and was not associated with any significant adverse events. However, the alveolar recruitment maneuver significantly reduced intraoperative peak inspiratory pressure. Further study is needed to validate the beneficial effect of the alveolar recruitment maneuver in patients at increased risk of postoperative pulmonary complications. Trial registration: Clinicaltrials.gov (NCT03681236).

An Update on Management of Adult Patients with Acute Respiratory Distress Syndrome: An Official American Thoracic Society Clinical Practice Guideline.

Background: This document updates previously published Clinical Practice Guidelines for the management of patients with acute respiratory distress syndrome (ARDS), incorporating new evidence addressing the use of corticosteroids, venovenous extracorporeal membrane oxygenation, neuromuscular blocking agents, and positive end-expiratory pressure (PEEP). Methods: We summarized evidence addressing four "PICO questions" (patient, intervention, comparison, and outcome). A multidisciplinary panel with expertise in ARDS used the Grading of Recommendations, Assessment, Development, and Evaluation framework to develop clinical recommendations. Results: We suggest the use of: 1) corticosteroids for patients with ARDS (conditional recommendation, moderate certainty of evidence), 2) venovenous extracorporeal membrane oxygenation in selected patients with severe ARDS (conditional recommendation, low certainty of evidence), 3) neuromuscular blockers in patients with early severe ARDS (conditional recommendation, low certainty of evidence), and 4) higher PEEP without lung recruitment maneuvers as opposed to lower PEEP in patients with moderate to severe ARDS (conditional recommendation, low to moderate certainty), and 5) we recommend against using prolonged lung recruitment maneuvers in patients with moderate to severe ARDS (strong recommendation, moderate certainty). Conclusions: We provide updated evidence-based recommendations for the management of ARDS. Individual patient and illness characteristics should be factored into clinical decision making and implementation of these recommendations while additional evidence is generated from much-needed clinical trials.

Updated Guidelines for Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) accounts for 10% of patients admitted to the intensive care unit and 23% of patients using mechanical ventilation, with a mortality rate of 45% in severe cases. The perception that patients with ARDS are vulnerable to ventilator-induced lung injury has led to lung-protective ventilation strategies. Accordingly, the American Thoracic Society, the European Society of Intensive Care Medicine (ESICM), and the Society of Critical Care Medicine announced ARDS mechanical ventilation guidelines in 2017. Since then, based on the results of newly reported research and data accumulated throughout the coronavirus disease 2019 pandemic, the ESICM announced an amendment to the previous guidelines in 2023. The revised ARDS guidelines discuss extending the ARDS definition and its phenotypes that were not mentioned in the previous guidelines. The new guidelines encompass ventilation strategies, including positive end-expiratory pressure and recruitment maneuvers in patients receiving mechanical ventilation. In addition, various oxygenation devices, such as high-flow nasal cannulated oxygen and continuous positive airway pressure in nonmechanically ventilated patients, are introduced. This review discusses new changes in the diagnosis and treatment of ARDS based on the new ESICM guidelines, providing a supportive background and rationale.

Evaluation of intra-cranial pressure changes by measuring the optic nerve sheath diameter during the lung recruitment maneuver in patients with acute respiratory distress syndrome: A prospective study.

The lung recruitment maneuver (LRM) applied in acute respiratory distress syndrome (ARDS) may increase the intra-cranial pressure (ICP). This study evaluated the effect of LRM on intra-cranial pressure changes in patients with ARDS by measuring the optic nerve sheath diameter (ONSD). LRM was applied to patients undergoing follow-up for ARDS, with a positive pressure of 30 cmH2O for 30 s. ONSD on ultra-sonography, dynamic lung compliance (Cdyn), oxygen saturation (SpO2), and hemodynamic parameters were measured before (T0), immediately after (T1), and 10 min after (T2) LRM. The primary endpoint was the effect of LRM on ONSD changes. The secondary endpoints included the effect of LRM on Cdyn, SpO2 change, and relationship between Cdyn and ONSD changes. The study included 60 patients. ONSD was higher at T1 than at T0 (median [interquartile range]: 5.13 [0.4] vs. 5.3 [0.3] mm, P < 0.001) but was similar at T0 and T2 (5.13 [0.4] vs. 5.09 [0.37] mm, P = 0.36). Cdyn and SpO2 were significantly higher at T1 and T2 than at T0 (Cdyn: 22.3 [5.8] vs. 23.7 [7.5] vs. 19.4 [6.6] mL/cmH2O, P < 0.001; SpO2: 90[2] vs. 92[4] vs. 88[4] %, P = 0.013). A significant correlation existed between Cdyn and ONSD changes, which increased at T2 compared to T0 (P < 0.001). LRM applied in ARDS causes a short-term increase in ONSD. However, Cdyn increases 10 min after LRM and causes ONSD, thereby leading to a decrease in ICP.

Use of Lung Ultrasound for Assessment of Lung Recruitment Maneuvers in Patients with ARDS

BACKGROUND: Positive pressure mechanical ventilation is a non-physiological intervention that saves lives but is not free of important side effects. It invariably results in different degrees of collapse of small airways. Recruitment maneuver (RM) aims to resolve lung collapse by a brief and controlled increment in airway pressure while positive end-expiratory pressure (PEEP) afterward keeps the lungs open. Therefore, ideally RM and PEEP selection must be individualized and this can only be done when guided by specific monitoring tools since lung’s opening and closing pressures vary among patients with different lung conditions. AIM: The aim of this study was to explore the clinical value of ultrasonic monitoring in the assessment of pulmonary recruitment and the best PEEP. PATIENTS AND METHODS: This study was conducted on 120 patients, 30 were excluded as in whom lung collapse cannot be confirmed then the rest were 90 patients from whom another 25 patients excluded as they were hemodynamically unstable the rest 65 patients were divided into two groups: Group A: Included 50 mechanically ventilated patients with ARDS, underwent lung recruitment using lung ultrasound and Group B: Included 15 mechanically ventilated patients with ARDS, underwent lung recruitment using oxygenation index. This prospective study was held at many critical care departments around Egypt. RESULTS: We noticed that lung recruitment in both groups significantly increased Pao2/Fio2 ratio immediately after recruitment compared with basal state and also significantly increase dynamic compliance compared with basal state. The increase in PF ratio immediately was significantly more in ultrasound group than in oxygenation group. Furthermore, we noticed that that P/F ratio 12 h after recruitment decreased compared with P/F ratio immediately after recruitment but significantly increased compared with basal state before recruitment and also we found that the increase in P/F ratio 12 h after recruitment was more significantly in lung ultrasound group than in oxygenation group. Furthermore, we noticed that lung recruitment (both lung ultrasound and oxygenation group) significantly increase RV function using TAPSE compared with basal state. Both opening pressure and optimal PEEP were significantly higher in lung ultrasound group than in oxygenation group. In our study, opening pressure was 37.28 ± 1.25 in lung ultrasound group and was 36.67±0.98 in oxygenation group and optimal PEEP was 14.64 ± 1.08 in lung ultrasound group and was 13.13 ± 0.74 in oxygenation group. CONCLUSION: Lung US is an effective mean of evaluating and guiding alveolar recruitment in ARDS. Compared with the maximal oxygenation–guided method, the protocol for reaeration in US-guided lung recruitment achieved a higher opening pressure, resulted in greater improvements in lung aeration, and substantially reduced lung heterogeneity in ARDS.

Recruitment maneuvers in patients undergoing thoracic surgery: a meta-analysis.

Pulmonary atelectasis is a common postoperative complication that may lead to intrapulmonary shunt, refractory hypoxemia, and respiratory distress. Recruitment maneuvers may relieve pulmonary atelectasis in patients undergoing thoracic surgery. This meta-analysis of randomized controlled trials (RCTs) is to evaluate the effectiveness and safety of recruitment maneuvers in patients undergoing thoracic surgery. We performed a literature search on the PubMed, Embase, and Cochrane Library databases and the ClinicalTrials.gov registry for trials published before April 2021. We investigated postoperative pulmonary atelectasis incidence, intrapulmonary shunt fraction, static lung compliance, and mean arterial pressure. Six RCTs involving 526 patients were reviewed. Patients receiving a recruitment maneuver exhibited a significant decrease in intrapulmonary shunt fraction [weighted mean difference (WMD) - 0.02, 95% CI - 0.03 to - 0.01], improved static lung compliance (WMD 2.16; 95% CI 1.14-3.18), and PaO2/FIO2 ratio (WMD 31.31; 95% CI 12.11-50.52) without a significant difference in mean arterial pressure (WMD - 0.64; 95% CI - 4.92 to 3.64). The incidence pulmonary atelectasis favored recruitment maneuver group, but was not statistically significant (RR 0.55; 95% CI 0.27-1.12). Recruitment maneuvers may be a viable treatment for reducing intra-pulmonary shunt and improving static lung compliance and PaO2/FIO2 ratio without the disturbance of hemodynamics in patients undergoing thoracic surgery.

Hemodynamic Effects of Changes in Transpulmonary Pressure During Recruitment Maneuver in Patients Under Pressure Supported Mechanical Ventilation

Hemodynamic Effects of Changes in Transpulmonary Pressure During Recruitment Maneuver in Patients Under Pressure Supported Mechanical Ventilation

The Strategy of "Pulmonary Opening by Titration of Positive End-expiratory Pressure" Means of a Pulmonary Recruitment Maneuver in Patients With Acute Respiratory Distress Syndrome: for Which Patients?

The Strategy of "Pulmonary Opening by Titration of Positive End-expiratory Pressure" Means of a Pulmonary Recruitment Maneuver in Patients With Acute Respiratory Distress Syndrome: for Which Patients?

Effects of Stepwise Lung Recruitment Maneuvers in Patients with Early Acute Respiratory Distress Syndrome: A Prospective, Randomized, Controlled Trial.

Since the clinical benefit of lung recruitment maneuvers (LRMs) is still conflicting, we performed this prospective, randomized, controlled study to investigate whether LRMs should be used in the routine management of acute respiratory distress syndrome (ARDS). This trial was conducted in four intensive care units (ICUs) to compare application of a modified stepwise LRMs with solely lung-protective ventilation in patients with moderate to severe ARDS within 72 h from the onset. The primary outcome was 28-day mortality, and the secondary outcomes were ventilator-free days and ICU-free days. We collected data on 120 ARDS patients from 2009 to 2012, and there was no difference in 28-day mortality between the two groups (28.3% vs. 30.0%, p = 0.84). However, among survivors, patients in the LRM group had a significant longer median duration of ventilator-free days (18 vs. 13 days; p = 0.04) and ICU-free days (16 vs. 11 days; p = 0.03) at 28 days than in the control group. The respiratory system compliance was significantly higher in the LRM group from day 1 to day 7. The occurrence rate of barotrauma was similar in both groups. We concluded that LRMs combined with lung-protective ventilation in early ARDS may improve patient outcomes.

Use of Recruitment Maneuvers in Patients With Acute Respiratory Distress Syndrome.

Acute respiratory distress syndrome (ARDS) is a deadly complication in critically ill patients that causes significant morbidity and mortality. Patients with ARDS are seen across intensive care unit settings, with treatment being largely supportive involving techniques through mechanical ventilation. Using low-tidal-volume ventilation is a standard of practice for patients with ARDS, as a lung protection strategy; however, alveolar decruitment may occur. Recruitment maneuvers can recruit collapsed alveoli and promote oxygenation. There are several methods of recruitment maneuvers-each with varying levels and durations of positive end-expiratory pressure. It is still uncertain which method is the best. The evidence for the efficacy of recruitment maneuvers has shown a decrease in intensive care unit mortality, but strong evidence is lacking for its routine use, and the decision to use recruitment maneuvers should be based on individual characteristics and responses. This article reviews management of ARDS, recruitment maneuver techniques, and clinical application through a case study.

Effect of protective lung ventilation strategy combined with lung recruitment maneuver in patients with acute respiratory distress syndrome (ARDS)

Objective: To evaluate the efficacy and safety of protective lung ventilation strategy combined with lung recruitment maneuver (RM) in the treatment patients with acute respiratory distress syndrome (ARDS). Methods: Totally 74 patients with ARDS admitted to the Department of Intensive Care Unit, Changshu Second People's Hospital in Jiangsu Province between September 2010 and June 2013 were selected and randomly divided into lung recruitment group and non-lung recruitment group, and the initial ventilation solution for both groups was synchronized intermittent mandatory ventilation (SIMV). For RM, SIMV mode (pressure control and pressure support) was adopted. Positive end expiratory pressure (PEEP) was increased by 5 cm H2O every time and maintained for 40-50 s before entering the next increasing period, and the peak airway pressure was kept below 45 cm H2O. After PEEP reached the maximum value, it was gradually reduced by 5 cm H2O every time and finally maintained at 15 cm H2O for 10 min. Results: A total of 74 patients with mean age of (49.0±18.6) years old were enrolled, 36 patients were enrolled in lung recruitment maneuver (RM) group and 38 patients were enrolled into non-lung recruitment maneuver (non-RM) group. 44 were male and accounted for 59.5% of all the patients. For the indicators such as PEEP, pressure support (PS), plateau airway pressure (Pplat), peak airway pressure (Ppeak), vital capacity (VC) and fraction of inspired oxygen (FiO2), no statistical differences in the indicators were found between the RM group and non-RM group on D1, D3 and D7 (P>0.05), except that only FiO2 of RM group on D7 was significantly lower than that of non-RM group (47.2±10.0) vs. (52.2±10.5), P 0.05). 28-day mortality, ICU mortality and in-hospital mortality were 25% vs. 28.9%, 25% vs. 26.3% and 36.1% vs. 39.5% respectively between RM group and non-RM group (all P>0.05). Conclusion: Protective lung ventilation strategy combined with lung recruitment maneuver can improve the indicators such as PaO2, FiO2 and PaO2/FiO2 on D7, but failed to improve the final outcomes such as 28-day mortality, ICU mortality and in-hospital mortality.

In Reply.

We thank Dr. Tusman et al. for their interest in our review on intraoperative protective ventilation.1 They claim that our recommendations neglected experimental and clinical evidence that disagree with the results of the recently published High versus Low Positive End-expiratory Pressure during General Anaesthesia for Open Abdominal Surgery (PROVHILO) study.2 Although inappropriate for drawing clinical recommendations, experimental studies provide the physiologic pillars of interventions. Therefore, our review article included a thorough appraisal of the mechanisms of ventilator-induced lung injury and possible strategies to prevent injury. Clinical recommendations must rely on clinical investigations, especially randomized controlled trials. Accordingly, we conducted a literature search and identified a few randomized controlled trials, which were ultimately meta-analyzed. Different from what Dr. Tusman et al. assert, selection was objective and unbiased. With 900 patients included in the study, the international, multicenter PROVHILO study2 is the largest randomized controlled trial in this field, and the meta-analysis was obviously influenced by this study’s results.When criticizing the recruitment maneuver used in PROVHILO study,2 Dr. Tusman et al. overlooked some basic mechanisms of recruitment and misunderstood the type of maneuver we applied. In the lungs, reopening of atelectatic tissue mimics avalanches, with different regions opening at distinct pressures and times.3 Furthermore, histologic analysis shows that approximately 5 s is enough to obtain recruitment once a particular opening pressure is exceeded.4 In PROVHILO study,2 the recruitment maneuver was based on a stepwise increase of tidal volumes at a positive end-expiratory pressure (PEEP) of 12 cm H2O. The time spent at different inspiratory pressures, including levels above 30 cm H2O, was approximately 15 s at each pressure. Thus, comparison with a maneuver based on the sustained inflation with PEEP of 0 cm H2O5 is misleading. In addition, the comparative increase in compliance was 33% on average, which in noninjured lungs ventilated with low tidal volume is more than modest and hardly explained by redistribution of ventilation without opening of atelectatic areas. We decisively disagree that the occurrence of postoperative atelectasis in PROVHILO study2 indicates inappropriate intraoperative lung recruitment. Pain, partial immobilization, and limited ability to cough, among many other postoperative factors, likely explain that finding and are obviously not related to intraoperative recruitment maneuvers.We are aware that intraoperative fluid loading could be harmful in patients undergoing surgery. Accordingly, the PROVHILO protocol recommended “to avoid fluid overload (according to the discretion of the attending anesthetist).” When judging this aspect, one must take the whole picture into account and consider that patients in the study underwent major open abdominal surgery, with significant blood loss and intravascular volume shifts.2 Therefore, and in contrast to the statement of Dr. Tusman et al., the incidence of postoperative pulmonary complications was as high as predicted in the risk category,6 whereas the risk of nonpulmonary complications was not assessed.Dr. Tusman et al. also overlooked the fact that our recommendations targeted nonobese patients undergoing open abdominal surgery only.1 In the publication that questioned our recommendations, other types of patients and surgical procedures were included.7 Furthermore, despite its impressive number of records, that single-center, retrospective study7 did not directly evaluate the role of PEEP on mortality.Future randomized controlled trials will show whether high PEEP level, individually titrated or not, with or without recruitment maneuvers, is superior to low PEEP level in terms of clinical outcome in other types of patients and surgical procedures. The current discussion reminds us of the debate about the studies that failed to demonstrate the usefulness of recruitment maneuvers in patients suffering from acute respiratory distress syndrome. For many years, “inappropriate maneuvers,” “nonindividualized PEEP levels,” “unsuitable therapy windows,” “meaningless endpoints,” and “inappropriate patient selection” were believed to be responsible for the lack of effect of recruitment maneuvers on clinically relevant endpoints. Enchanted by aseptic lung injury models that reproduced some but not all relevant aspects of the complex clinical scenario, passionate researchers have insisted on their own beliefs, denied clinical evidence, and put patients at risk.For our group, stating that future studies might lead to adjustments in recommendations is not paradoxical but rather reflects our principle of being open to evidence from ever evolving experimental and clinical research. This is how we understand science targeted at improving patient care.The authors declare no competing interests.

Dead Space Fraction: One of Many Choices to Assess PEEP Titration

In their prospective trial on PEEP titration following recruitment maneuver in patients with ARDS, Fengmei et al provided a well controlled study on the effects of the ratio of dead space to tidal volume (VD/VT).[1][1] Changes in compliance, functional residual capacity, and PaO2/FIO2 after the

Complications From Recruitment Maneuvers in Patients With Acute Lung Injury: Secondary Analysis From the Lung Open Ventilation Study

There are limited data on the safety and efficacy of recruitment maneuvers (RMs) in acute lung injury (ALI) patients. To evaluate the frequency, timing, and risk factors for complications from RMs in adult ALI patients. Secondary analysis of data from a randomized controlled trial of a lung open ventilation strategy that included sustained inflation RMs. Respiratory (eg, desaturation) and cardiovascular (eg, hypotension) complications from recruitment maneuvers were common (22% of all patients receiving RMs), and the majority occurred within 7 days of enrollment. New air leak through an existing chest tube was uncommon (< 5%). As compared to patients receiving 1 or fewer RMs, the number of RMs received was associated with increased risk in both younger (age ≤ 56 y) and older patients (age > 56 y): 2 RMs odds ratio [OR] 6.92 (95% CI 1.70-28.2), ≥ 3 RMs OR 15.4 (95% CI 4.77-49.6), and 2 RMs OR 5.43 (95% CI 1.76-16.8), ≥ 3 RMs OR 4.93 (95% CI 1.78-13.7), respectively. Patients with extrapulmonary ALI had decreased odds of developing complications (OR 0.42, 95% CI 0.22-0.80). Complications in adult ALI patients receiving RMs were common, but serious complications (eg, new air leak through an existing chest tube) were infrequent. There is a significant association between the number of RMs received and complications, even after controlling for illness severity and duration. Given their uncertain benefit in ALI patients, and the potential for complications with repeated application, the routine use of sustained inflation RMs is not justified.

Effects of high positive end-expiratory pressure combined with recruitment maneuvers in patients with acute respiratory distress syndrome

To investigate the clinical effects and safety degree of high positive end-expiratory pressure (PEEP) combined with lung recruitment maneuver (RM) in patients with acute respiratory distress syndrome (ARDS). Thirty-eight patients in medical intensive care unit (MICU) of Affiliated Hospital of Guiyang Medical College suffering from ARDS admitted from June 2008 to May 2010 were enrolled in the study. With the envelope method they were randomized into RM group and non-RM group, with n=19 in each group. All patients received protective ventilation: pressure support ventilation (PSV) with plateau pressure limited at 30 cm H(2)O (1 cm H(2)O=0.098 kPa) or lower. PEEP was set at the minimum level with fraction of inspired oxygen (FiO(2)) <0.60 and partial pressure of arterial oxygen (PaO(2)) kept between 60 and 80 mm Hg (1 mm Hg=0.133 kPa). RM was conducted by regulating FiO(2) to 1.00, support pressure to 0, PEEP increased to 40 cm H(2)O and maintained for 30 seconds before lowering, and this maneuver was repeated every 8 hours for a total of 5 days. Base status, ventilation parameters, blood gas analysis and vital signs were obtained at baseline and for the next 5 days. Oxygenation status and lung injury indexes were compared between RM group and non-RM group, the adverse effects of RM and incidence of barotrauma were recorded. ¹ There were no significant differences of base status and ventilation parameters between RM group and non-RM group. ²PaO(2) and oxygenation index (PaO(2)/FiO(2)) were both increased in RM group and non-RM group, but the values were higher in RM group [PaO(2)(mm Hg) 2 days: 85.8±21.3 vs. 73.5±18.7, 3 days: 88.6±22.8 vs. 74.3±19.8, 4 days: 98.8±30.7 vs. 79.3±19.3, 5 days: 105.5±29.4 vs. 84.4±13.8; PaO(2)/FiO(2) (mm Hg) 4 days: 221.8±103.5 vs. 160.3±51.4, 5 days: 239.6±69.0 vs. 176.8±45.5, all P<0.05]. ³ Hydrogen peroxide (H(2)O(2)) and interleukin-6 (IL-6) concentration in exhaled breath condensate (EBC) decreased in both groups but lower in RM group with significant difference [5 days H(2)O(2) (μmol/L): 0.04±0.02 vs. 0.10±0.03; IL-6 (ng/L): 4.12±2.09 vs. 9.26±3.47, both P<0.05]. (4) Barotrauma and arrhythmia did not occur in both groups. No significant changes in heart rate were found during RM. Central venous pressure and mean arterial pressure remained unchanged after RM. High level PEEP combined with RM can improve gas exchange and oxygenation, decrease ventilator associated lung injury (VALI). RM was safe and had good tolerance, no hypoxemia, barotrauma and hemodynamic instability were observed.

A comparison between two different alveolar recruitment maneuvers in patients with acute respiratory distress syndrome

Background:Alveolar recruitment is a physiological process that denotes the reopening of previously gasless lung units exposed to positive pressure ventilation. The current study was aimed to compare two recruitment maneuvers, a high continuous positive airway pressure (CPAP), and an extended sigh in patients with ARDS.Materials and Methods:Forty patients with acute respiratory distress syndrome were randomly divided into two groups, 20 patients each. Group I received a CPAP of 40 cm H2O for 40 seconds and group II received extended sigh (providing a sufficient recruiting pressure × time). In our study, we assessed the effects of both recruitment maneuvers on respiratory mechanics, gas exchange, and hemodynamics. These data were analyzed using two-way analysis of variance (ANOVA) followed by a Student--Newman--Keuls post hoc comparison test. P < 0.05 was considered statistically significant.Results:Both methods improved the compliance, increased arterial oxygenation (PaO2), increased the PaO2/FiO2 ratio, and reduced the pulmonary shunt fraction (Qs/Qt). However, the extended sigh improved both PaO2 and PaO2/FiO2 ratios more than continuous positive airway pressure. Also the hemodynamic parameters were better maintained during the extended sigh.Conclusion:Alveolar recruitment maneuvers are effective in management of mechanically ventilated ARDS patients. We conclude that extended sigh is more effective than continuous positive airway pressure as a recruitment maneuver.

Efficacy of Alveolar Recruitment Maneuvers in Patients With Complicated Thoracic Trauma

The objective of this study was to measure the efficacy of biphasic positive airway pressure (BIPAP) and synchronized intermittent mandatory ventilation (SIMV) with alveolar recruitment maneuvers (ARMs) in patients with acute lung injury (ALI) and concomitant pneumothorax. Seventy-four patients with ALI and concomitant pneumothorax secondary to blunt thoracic injury were studied. All patients fulfilled criteria for the first stage of acute respiratory distress syndrome, which consisted of acute onset dyspnea, isolated rales, an extravascular lung water index >7 mL/kg, and an oxygenation index <300 mm Hg in the absence of left-ventricular dysfunction. After evacuation of the pneumothorax, ARMs were performed using BIPAP or SIMV 3 to 5 times a day with a peak pressure of 33.4 ± 0.2 cm H(2)O and a positive end-expiratory pressure of 16.1 ± 0.2 cm H(2)O. The use of BIPAP in patients with ALI and concomitant pneumothorax reduced the time to resolution of the air leak allowing application of earlier ARMs. ARMs with peak pressures of 35 to 40 cm H(2)O effectively improved oxygenation and biomechanical properties of the lungs and did not cause pneumothorax relapse. In conclusion, BIPAP allowed for spontaneous ventilation during the breathing cycle and limited P (peak). Its use was associated with more rapid sealing of air leaks with the ability to conduct earlier ARMs. The use of BIPAP compared with SIMV improved outcome in the presence of complex thoracic trauma.

Alveolar recruitment maneuver in patients with subarachnoid hemorrhage and acute respiratory distress syndrome: A comparison of 2 approaches

Purpose The purpose of the study was to compare 2 alveolar recruitment maneuvers (ARMs) approaches in patients with subarachnoid hemorrhage (SAH) and acute respiratory distress syndrome (ARDS). Material and Methods Sixteen SAH patients with ARDS were randomized in 2 similar groups. One received ARM with continuous positive airway pressure (CPAP) of 35 cm H 2O for 40 seconds (CPAP recruitment), whereas the other received pressure control ventilation with positive-end expiratory pressure of 15 cm H 2O and pressure control above positive end-expiratory pressure of 35 cm H 2O for 2 minutes (pressure control recruitment maneuver [PCRM]). Intracranial pressure (ICP) and cerebral perfusion pressure (CPP) were measured before and after ARM. The ratio of arterial oxygen tension to fraction of inspired oxygen was measured before and 1 hour after the ARM. Results After ARM, ICP was higher in CPAP recruitment (20.50 ± 4.75 vs 13.13 ± 3.56 mm Hg; P = .003); and CPP was lower in CPAP recruitment (62.38 ± 9.81 vs 79.60 ± 6.8 mm Hg; P = .001). One hour after the ARM, the ratio of arterial oxygen tension to fraction of inspired oxygen increased significantly only in PCRM (108.5 to 203.6; P = .0078). Conclusion In SAH patients with ARDS, PCRM did not affect ICP and decreased CPP in safe levels, besides improving oxygenation.

Lung morphology predicts response to recruitment maneuver in patients with acute respiratory distress syndrome

The impact of recruitment maneuvers on gas exchange, hemodynamics, alveolar recruitment, and hyperinflation is highly variable among patients with acute respiratory distress syndrome. The objective was to determine whether differences in lung morphology, defined as differences in the pulmonary distribution of aeration loss, predict the response to recruitment maneuvers. Prospective study. A 16-bed medical-surgical intensive care unit in a university hospital. Nineteen consecutive patients with early acute lung injury/acute respiratory distress syndrome were studied. Computed tomography scans, respiratory mechanics, hemodynamics, and gas exchange were obtained at zero end-expiratory pressure during an open-lung ventilation (controlled mode, tidal volume 6 mL/kg of ideal body weight, positive end-expiratory pressure set 2 cm H2O above the lower inflection point of the inspiratory pressure volume curve at zero end-expiratory pressure) during a recruitment maneuver (continuous positive airway pressure of 40 cm H2O for 40 secs), and, finally, 5 mins after the recruitment maneuver during open-lung ventilation. Nine patients presented focal and 10 presented nonfocal lung morphology at zero end-expiratory pressure. Recruitment maneuver-induced recruited volume after 5 mins of open-lung ventilation was 48 +/- 66 mL and 417 +/- 293 mL in patients with focal and nonfocal lung morphology, respectively (p = .0009). Recruitment maneuver-induced alveolar hyperinflation represented 23% +/- 14% and 8% +/- 9% of total lung volume in patients with focal and nonfocal morphology, respectively (p = .007). In patients with focal lung morphology, hyperinflated lung volume was significantly greater during and 5 mins after (316 +/- 155 mL) than immediately before recruitment maneuvers (150 +/- 175 mL; p = .0407. Lung morphology at zero end-expiratory pressure predicts the response to recruitment maneuvers. Patients with focal lung morphology are at risk for significant hyperinflation during the recruitment maneuvers, and lung recruitment is rather limited.

Acute Hemodynamic Effects of Recruitment Maneuvers in Patients With Acute Respiratory Distress Syndrome

The recruitment maneuver (RM) in acute respiratory distress syndrome (ARDS) can cause hemodynamic derangement. We evaluated circulatory and cardiac changes during RMs. We performed sustained inflation (SI) with a pressure of 40 cm H(2)O for 30 seconds as an RM on 22 patients with ARDS. Blood pressure (BP) and heart rate were recorded immediately before, every 10 seconds during, and 30 seconds after the RM. Ventricular dimensions were obtained simultaneously using M-mode echocardiography, and tissue Doppler imaging was performed on the left ventricular wall. Mean, systolic, and diastolic BP decreased at 20 and 30 seconds during 30-second RMs (mean BP: 92 +/- 12 at baseline to 83 +/- 18 mm Hg at the end of the RM, P < .05) and subsequently recovered. Heart rate decreased at 10 and 20 seconds during the RM, and tended to increase afterward. Both ventricular dimensions decreased significantly during the RM. The left ventricular ejection fraction and peak velocity of the left ventricle during systole remained stable. The fractional changes in mean BP and left ventricular end-diastolic dimension during the RMs were correlated significantly with each other (r(s) = 0.59). Static compliance of the respiratory system (Crs) was lower in patients with mean BP change > or =15% than in patients in whom the change was <15% (P < .05). A transient decrease in mean BP was observed during the RM, and its degree was correlated with the preload decrease, while cardiac contractility was maintained.