This letter was sent to the author of the original article referenced above, who declined to respond.—Evan D. Kharasch, M.D., Ph.D., Editor-in-Chief, (Accepted for Publication July 15, 2020. 5 Typically, patients remain supine during mechanical ventilation; however, prone positioning has been used for the treatment of ARDS since the 1970s. Uncertainty remains regarding the differences in efficacy and safety for prone versus supine positioning in ventilation of adults with ARDS. Sixty patients with severe ARDS were randomized to supine and 76 to prone ventilation. Treatment guidelines suggest maintaining oxygen saturation >90%; a ratio of PaO 2 to FiO 2 >200; a pH of 7.25–7.40, and a plateau pressure <35 cm H 2 O. ventilation in the prone compared with supine position in patients with ALI, ARDS, and acute hypoxemic respira-tory failure [28]. Our findings indicate that ARDS patients that underwent ventilation with prone positioning might experience lower risk of mortality, shorter mechanical ventilation duration, and longer ICU stays, although the pooled effect estimates suggest no significant differences between groups. The purpose of this meta-analysis was to compare the efficacy and safety of prone versus supine position ventilation for adult acute respiratory distress syndrome (ARDS) patients. Sensitivity analyses for mortality, mechanical ventilation duration, and ICU stays were conducted to assess the robustness of pooled results [18]. A systematic review and metaanalysis,”, L. Munshi, L. Del Sorbo, N. K. J. Adhikari et al., “Prone position for acute respiratory distress syndrome. [22] or Guérin et al. Heterogeneity tests were conducted using I2 and Q statistic, and I2 ≥ 50.0% or  < 0.10 was regarded as significant heterogeneity [16, 17]. identified 7 RCTs and found that prone position ventilation could decrease mortality risk for patients with low tidal volume, prolonged pronation, starting within the first 48 hours of disease evolution, and severe hypoxemia [39]. Sensitivity for duration of mechanical ventilation. Prone ventilation was carried out for an average of 17 hours per day for a mean duration of 10.1 ± 10.3 days. However, it is not certain whether other positions, for example, “face-down” (prone position), could be more advantageous for breathing or other pursuits, including survival. Review articles are excluded from this waiver policy. Anesthesiology 2020; 133:1155–1157 doi: https://doi.org/10.1097/ALN.0000000000003511, PRONE positioning is a simple method to improve oxygenation in ventilated patients with acute respiratory distress syndrome (ARDS).1  Potential explanations are reduction of ventilation/perfusion mismatch, a more homogeneous distribution of transpulmonary pressure along the ventral-to-dorsal axis, and recruitment of nonaerated dorsal lung regions of the lung, with an increase in lung volume.2  Many of these mechanisms could also apply to awake patients with ARDS by COVID-19.3. Data abstraction and quality assessment were carried out by two authors, and any disagreements were settled by an additional author. Here, we present an image (fig. The findings of this study indicate that prone positioning might play an important role on the risk of mortality, especially for patients <60.0 years old, percentage male <70.0%, or intervention used with protective lung ventilation. Prone versus supine position ventilation on the risk of mortality. [25] (Table 2). Compared with the supine position (SP), placing patients in PP effects a more even tidal volume distribution, in part, by reversing the vertical pleural pressure gradient, which becomes more negative in the dorsal regions. Minor reversible complications occurred in 6% of prone positioning cases. The relative risks (RRs) and weighted mean differences (WMDs) with corresponding 95% confidence intervals (CIs) were employed to calculate pooled outcomes using the random-effects models. Arterial blood gas analysis in the supine position with high-flow nasal cannula oxygen therapy (50% concentration; flow rate, 50 l/min) showed Pao2/fractional inspired oxygen tension (Fio2) of 130, with an improvement in... Search for other works by this author on: Clinical University Hospital of Santiago, Spain, and Sanitary Research Institute of Santiago (FIDIS), Santiago de Compostela, Spain (M.T.). In 2014, they update this study and contained 11 RCTs. Seven of the included trials were of high quality (two studies had Jadad scores of 6, and five studies had Jadad scores of 5), and the remaining five trials were of low quality (three studies had Jadad scores of 4, one study had a score of 3, and the remaining study had a score of 2). The sensitivity analyses indicated that prone versus supine positioning might be associated with shorter mechanical ventilation duration and longer ICU stays (Figures 5 and 6). Prone versus supine position ventilation on ICU stays. There was a significant improvement in oxygenation during prone positioning (PaO 2 /FiO 2 181 mm Hg in supine position vs. PaO 2 /FiO 2 286 mm Hg in prone position). ASA members enjoy complimentary access to ASA publications, as well as a variety of educational resources. No differences in mortality or complications were identified for the prone versus … The mechanisms included improved ventilation-perfusion matching, end-expiratory lung volume, and ventilator-induced lung injury [10, 11]. At this point, it’s likely that intubation and mechanical ventilation will be … Moreover, we noted that prone versus supine positioning was associated with lower risk of mortality when the mean age of the patients was <60.0 years, the percentage of male patients was <70.0%, or intervention was used as protective lung ventilation. V distribution is independent of posture. In the prone position, the lungs' dorsal aspects have less pleural pressure, which alleviates forces trying to collapse the alveoli. Copyright © 2020, the American Society of Anesthesiologists, Inc. All Rights Reserved. 1) from a computed tomography performed in a 71-yr-old woman with ARDS from COVID-19 in both supine and prone positioning during awake spontaneous ventilation. Unadjusted 90-day mortality was 23.6% in the prone group versus 41.0% in the supine group (P<0.001), with a hazard ratio of 0.44 (95% CI, 0.29 to 0.67). A systematic review and meta-analysis,”, L. Gattinoni and A. Protti, “Ventilation in the prone position: for some but not for all?”, L. Gattinoni and A. Pesenti, “The concept of“baby lung,”, R. G. Brower, M. A. Matthay, A. Morris, D. Schoenfeld, B. T. Thompson, and A. Wheeler, “Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome,”, M. Briel, M. Meade, A. Mercat et al., “Higher vs lower positive end-expiratory pressure in patients with acute lung injury and acute respiratory distress syndrome: systematic review and meta-analysis,”. Baseline characteristics of the included studies. The mortality rates in the five trials that included lung protective ventilation (19,20,29,30) were reduced in the context of prone positioning, but all-cause mortality in the three trials not including lung protective ventilation differ according to prone or supine positioning. This site uses cookies. A trial, meta-analysis and review also “support the early use of prone ventilation in patients with moderate to severe ARDS to improve oxygenation and reduce mortality,” that article found. The pooled RRs indicate that patients who received prone position ventilation had increased incidence of pressure scores (RR: 1.23;  = 0.003), displacement of a thoracotomy tube (RR: 3.14;  = 0.047), and endotracheal tube obstruction (RR: 2.45;  = 0.001). This work was supported by the 2017 Guangdong Medical Research Fund Project (grant no. “If the patient cannot tolerate the prone position, or has worsening hypoxia, work of breathing or tachycardia, the patient is returned to the supine position and their head-of-bed elevated. The summary results indicate that prone versus supine positioning was not associated with risk of mortality, though this conclusion was not stable and could have been affected by two specific individual trials [22, 25]. These conclusions are not stable and could be altered by excluding individual trials. Publication bias for mortality was assessed by funnel plots, Egger’s test, and Begg’s test, and the results suggest potential publication bias for mortality ( value for Egger’s test: 0.076; value for Begg’s test: 0.276; Figure 7). The pooled results suggest that the risk of mortality was reduced by 13% for prone versus supine position ventilation, though this reduced risk was not statistically significant (RR: 0.87; 95% CI: 0.75–1.00;  = 0.055; Figure 2). Therefore, efforts to limit mechanical lung injury during invasive ventilation are widely used for improving survival in ARDS patients [7]. The differences between subgroups were assessed by using the interaction P test [19]. Moreover, the risk of pressure scores, displacement of a thoracotomy tube, and endotracheal tube obstruction were significantly increased in ARDS patients received prone positioning. The effects of prone versus supine position ventilation on the risk of mortality were reported in 11 RCTs. Published online first on August 3, 2020. Lung ventilation and perfusion in prone and supine postures with reference to anesthetized and mechanically ventilated healthy volunteers During mechanical ventilation, prone posture favors a more evenly distributed Q between lung regions. Furthermore, the heterogeneity across included trials for mechanical ventilation duration, which could be explained by various characteristics and disease status for included patients. Overall, a total of 2264 adults with ARDS from 12 RCTs were included in this study, and the sample sizes ranged from 16 to 791. Thus, that it is dependent at both postures. Compared to the prior CT, the supine scan showed a significant increase in the extent and atten-uation of the opacities with pulmonary consolidation and atelectasis of the right lower lobe. The pooled results of this study indicate no significant differences between prone and supine positioning for mechanical ventilation duration and ICU stays. Mechanical ventilation is widely used to improve oxygenation and reduce harmful effects in ARDS patients, though whether prone positioning during ventilation can improve clinical endpoints versus supine positioning remains unclear. There were no significant differences between prone and supine position ventilation on the duration of mechanical ventilation (WMD: −0.22;  = 0.883) or ICU stays (WMD: –0.39;  = 0.738). Total duration of ARDS <36h Twelve randomized controlled trials that had recruited a total of 2264 adults with ARDS were selected for the final meta-analysis. Munshi et al. In the supine group, measurements were performed every 6 hours; in the prone group, measurements were performed just before the patient was turned to the prone position, after 1 … Invasive mechanical ventilation is traditionally delivered with the patient in the supine position. The electronic databases of PubMed, Embase, and the Cochrane Library were systematically searched from their inception up to September 2020. COVID-related ARDS, following a 12-24h stabilization period, with all of the following: 1. Thus, a prone-to-supine change would be the opposite of what Lemaire and colleagues observed when removing positive pressure . However, the limitations of these studies included several other efficacy and safety outcomes were not calculated, or subgroup analyses for the risk of mortality according to other patients’ characteristics were not presented. The mortality of ARDS remains high, and the pooled mortality rate in our meta-analysis was 43%, ranging from 26% to 58% [2–4]. The authors declare that there are no conflicts of interest regarding the publication of this paper. PEEP >10% 5. The treatment effectiveness of prone versus supine position ventilation were assigned as dichotomous and continuous data, and the relative risks (RRs) and weighted mean differences (WMDs) with 95% confidence intervals (CIs) were calculated before data pooling. In the supine position, the fluid distributes itself throughout both lungs in virtually all lung fields but most significantly in the dorsal regions where the most perfusion takes place. Although not statistically significant, lower ICU mortality was observed among patients who underwent prone ventilation (43% vs. 58%, p=0.12). We are committed to sharing findings related to COVID-19 as quickly as possible. ), Manuel Taboada, Anaberta Bermúdez, María Pérez, Olga Campaña; Supine versus Prone Positioning in COVID-19 Pneumonia: Comment. A2017567) and 2020 Natural Science Foundation of Guangdong Province (grant no.2020A1515010383). In 1978, Rehder et al. Six RCTs included patients that received protective lung ventilation, and the remaining six studies included patients that did not receive protective lung ventilation. conducted a meta-analysis of 8 RCTs and found that prone positioning is associated with lower risk of mortality among patients with moderate to severe ARDS, or applied prone positioning for at least 12 hours daily [40]. Two authors independently conducted the study selection, and any conflicts were settled by discussion until a consensus was reached. The effects of prone versus supine position ventilation on the risk of mortality were reported in 11 RCTs. Patients that failed non-invasive ventilation and required invasive mechanical ventilation (NIV+IMV group) are shown in blue and non-invasive ventilation (NIV) only group in red. The prone scan showed a partial recovery of the aerated lung parenchyma in the right inferior lobe with a small area of residual consolidation in the posterior segment of the right lower lobe. The prone position, during mechanical ventilation, for patients with acute hypoxaemic respiratory failure, significantly reduced overall mortality. The inclusion criteria included: (1) patients, adults with ARDS; (2) intervention, prone position; (3) control, supine position; (4) outcomes, efficacy outcomes including mortality, mechanical ventilation duration, and ICU stays, and the safety outcomes, including any adverse events reported ≥2 studies; and (5) study design: RCT. Finally, the treatment effectiveness of prone versus supine positioning on the risk of mortality could affect by percentage male, and whether used as protective lung ventilation. The results indicated that prone positioning during ventilation might have a beneficial effect on mortality, though incidence of several adverse events was significantly increased for these patients. Featured in the book,”AACN Procedure Manual for High Acuity, Progressive, and Critical Care.7th ed. The physiologic mechanism can be explained by a gravity-dependent increase in pleural pressure when supine compared to prone. involved 9 RCTs and found prone ventilation was associated with a reduced risk of mortality in patients with severe hypoxemia [6]. Numerous randomized controlled trials (RCTs) comparing prone position ventilation with supine positioning have been conducted, and the results are varied. No significant differences between prone and supine positioning were observed for the risks of displacement of tracheal tube (RR: 1.35; 95% CI: 0.47–3.84;  = 0.579), unplanned extubation (RR: 1.02; 95% CI: 0.73–1.43;  = 0.906), selective intubation (RR: 2.64; 95% CI: 0.26–26.73;  = 0.411), loss of venous access (RR: 1.52; 95% CI: 0.22–10.26;  = 0.669), hemoptysis (RR: 0.85; 95% CI: 0.35–2.05;  = 0.717), cardiac arrest (RR: 0.71; 95% CI: 0.40–1.26;  = 0.245), pneumothorax (RR: 0.86; 95% CI: 0.58–1.29;  = 0.471), and ventilator-associated pneumonia (RR: 1.34; 95% CI: 0.65–2.76;  = 0.427). No significant differences between prone and supine positioning on mechanical ventilation duration (WMD: –0.22; 95% CI: –3.14 to 2.70;  = 0.883; Figure 3) or ICU stays (WMD: –0.39; 95% CI: –2.70 to 1.91;  = 0.738; Figure 4) were detected. Also, Patients were divided into a prone ventilation group and a supine ventilation group when the treatment for ARDS was started. The Jadad scale, taking into consideration randomization, blinding, allocation concealment, withdrawals and dropouts, and use of intention-to-treat analysis, was applied to assess the quality of included studies [13]. A. Mora-Arteaga, O. J. Bernal-Ramírez, and S. J. Rodríguez, “The effects of prone position ventilation in patients with acute respiratory distress syndrome. Eight RCTs were conducted in a single country, while four were multicenter studies conducted in two countries. 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Tobias, “Assessing the influence of a single study in the meta-analysis estimate,”, D. G. Altman and J. M. Bland, “Interaction revisited: the difference between two estimates,”, M. Egger, G. Davey Smith, M. Schneider, and C. Minder, “Bias in meta-analysis detected by a simple, graphical test,”, C. B. Begg and M. Mazumdar, “Operating characteristics of a rank correlation test for publication bias,”, L. Gattinoni, G. Tognoni, A. Pesenti et al., “Effect of prone positioning on the survival of patients with acute respiratory failure,”, P. Beuret, M. J. Carton, K. Nourdine, M. Kaaki, G. Tramoni, and J. C. Ducreux, “Prone position as prevention of lung injury in comatose patients: a prospective, randomized, controlled study,”, I. Watanabe, H. Fujihara, K. Sato et al., “Beneficial effect of a prone position for patients with hypoxemia after transthoracic esophagectomy,”, C. Guerin, S. Gaillard, S. Lemasson et al., “Effects of systematic prone positioning in hypoxemic acute respiratory failure: a randomized controlled trial,”, L. Papazian, M. Gainnier, V. Marin et al., “Comparison of prone positioning and high-frequency oscillatory ventilation in patients with acute respiratory distress syndrome,”, G. Voggenreiter, M. Aufmkolk, R. J. Stiletto et al., “Prone positioning improves oxygenation in post-traumatic lung injury--a prospective randomized trial,”, J. Mancebo, R. Fernandez, L. Blanch et al., “A multicenter trial of prolonged prone ventilation in severe acute respiratory distress syndrome,”, D. Demory, P. Michelet, J. M. Arnal et al., “High-frequency oscillatory ventilation following prone positioning prevents a further impairment in oxygenation,”, M. C. Chan, J. Y. Hsu, H. H. Liu et al., “Effects of prone position on inflammatory markers in patients with ARDS due to community-acquired pneumonia,”, R. Fernandez, X. Trenchs, J. Klamburg et al., “Prone positioning in acute respiratory distress syndrome: a multicenter randomized clinical trial,”, P. Taccone, A. Pesenti, R. Latini et al., “Prone positioning in patients with moderate and severe acute respiratory distress syndrome: a randomized controlled trial,”, C. Guerin, J. Reignier, J. C. Richard et al., “Prone positioning in severe acute respiratory distress syndrome,”, S. Duval and R. Tweedie, “A nonparametric “trim and fill” method of accounting for publication bias in meta-analysis,”, A. H. Alsaghir and C. M. Martin, “Effect of prone positioning in patients with acute respiratory distress syndrome: a meta-analysis,”, S. Sud, J. O. Friedrich, N. K. Adhikari et al., “Effect of prone positioning during mechanical ventilation on mortality among patients with acute respiratory distress syndrome: a systematic review and meta-analysis,”, S. L. Hu, H. L. He, C. Pan et al., “The effect of prone positioning on mortality in patients with acute respiratory distress syndrome: a meta-analysis of randomized controlled trials,”, J. M. Lee, W. Bae, Y. J. Lee, and Y. J. Cho, “The efficacy and safety of prone positional ventilation in acute respiratory distress syndrome: updated study-level meta-analysis of 11 randomized controlled trials,”, J. However, these results were based on a smaller number of included trials, and this result needs to be verified by a large-scale RCT. A funnel plot, Egger’s test, and Begg’s test were used to assess publication bias for mortality [20, 21]. The study conducted by Taccone et al. Therefore, it is incorporated into regular clinical practice of managing patients with ARDS in critical care and … The risks of adverse events between prone and supine positioning are summarized in Table 4. Acute respiratory distress syndrome (ARDS) is a serious disorder in critically ill patients that is characterized by disrupted endothelial barriers, abnormal alveolar epithelium, pulmonary vascular permeability, and protein-rich pulmonary edema [1]. Finally, the interaction P test indicated that the treatment effect of prone versus supine positioning on mortality could be affected by the percentage of male patients ( = 0.001), and whether used as protective lung ventilation ( = 0.012). A meta-analysis conducted by Alsaghir and Martin contained five studies and found that prone positioning did not yield additional benefits with regard to mortality, whereas it improved oxygenation as compared with supine positioning.