Inferior vena cava distensibility during pressure support ventilation: a prospective study evaluating interchangeability of subcostal and trans­hepatic views, with both M­mode and automatic border tracing.

The Inferior Vena Cava (IVC) is commonly utilized to evaluate fluid status in the Intensive Care Unit (ICU),with more recent emphasis on the study of venous congestion. It is predominantly measured via subcostal approach (SC) or trans-hepatic (TH) views, and automated border tracking (ABT) software has been introduced to facilitate its assessment. Prospective observational study on patients ventilated in pressure support ventilation (PSV) with 2 × 2 factorial design. Primary outcome was to evaluate interchangeability of measurements of the IVC and the distensibility index (DI) obtained using both M-mode and ABT, across both SC and TH. Statistical analyses comprised Bland-Altman assessments for mean bias, limits of agreement (LoA), and the Spearman correlation coefficients. IVC visualization was 100% successful via SC, while TH view was unattainable in 17.4% of cases. As compared to the M-mode, the IVC-DI obtained through ABT approach showed divergences in both SC (mean bias 5.9%, LoA -18.4% to 30.2%, ICC = 0.52) and TH window (mean bias 6.2%, LoA -8.0% to 20.4%, ICC = 0.67). When comparing the IVC-DI measures obtained in the two anatomical sites, accuracy improved with a mean bias of 1.9% (M-mode) and 1.1% (ABT), but LoA remained wide (M-mode: -13.7% to 17.5%; AI: -19.6% to 21.9%). Correlation was generally suboptimal (r = 0.43 to 0.60). In PSV ventilated patients, we found that IVC-DI calculated with M-mode is not interchangeable with ABT measurements. Moreover, the IVC-DI gathered from SC or TH view produces not comparable results, mainly in terms of precision.

Inferior vena cava distensibility from subcostal and trans-hepatic imaging using both M-mode or artificial intelligence: a prospective study on mechanically ventilated patients.

BACKGROUND: Variation of inferior vena cava (IVC) is used to predict fluid-responsiveness, but the IVC visualization with standard sagittal approach (SC, subcostal) cannot be always achieved. In such cases, coronal trans-hepatic (TH) window may offer an alternative, but the interchangeability of IVC measurements in SC and TH is not fully established. Furthermore, artificial intelligence (AI) with automated border detection may be of clinical value but it needs validation. METHODS: Prospective observational validation study in mechanically ventilated patients with pressure-controlled mode. Primary outcome was the IVC distensibility (IVC-DI) in SC and TH imaging, with measurements taken both in M-Mode or with AI software. We calculated mean bias, limits of agreement (LoA), and intra-class correlation (ICC) coefficient. RESULTS: Thirty-three patients were included. Feasibility rate was 87.9% and 81.8% for SC and TH visualization, respectively. Comparing imaging from the same anatomical site acquired with different modalities (M-Mode vs AI), we found the following IVC-DI differences: (1) SC: mean bias - 3.1%, LoA [- 20.1; 13.9], ICC = 0.65; (2) TH: mean bias - 2.0%, LoA [- 19.3; 15.4], ICC = 0.65. When comparing the results obtained from the same modality but from different sites (SC vs TH), IVC-DI differences were: (3) M-Mode: mean bias 1.1%, LoA [- 6.9; 9.1], ICC = 0.54; (4) AI: mean bias 2.0%, LoA [- 25.7; 29.7], ICC = 0.32. CONCLUSIONS: In patients mechanically ventilated, AI software shows good accuracy (modest overestimation) and moderate correlation as compared to M-mode assessment of IVC-DI, both for SC and TH windows. However, precision seems suboptimal with wide LoA. The comparison of M-Mode or AI between different sites yields similar results but with weaker correlation. Trial registration Reference protocol: 53/2022/PO, approved on 21/03/2022.

Assessment of the inferior vena cava collapsibility from subcostal and trans-hepatic imaging using both M-mode or artificial intelligence: a prospective study on healthy volunteers.

PURPOSE: Assessment of the inferior vena cava (IVC) respiratory variation may be clinically useful for the estimation of fluid-responsiveness and venous congestion; however, imaging from subcostal (SC, sagittal) region is not always feasible. It is unclear if coronal trans-hepatic (TH) IVC imaging provides interchangeable results. The use of artificial intelligence (AI) with automated border tracking may be helpful as part of point-of-care ultrasound but it needs validation. METHODS: Prospective observational study conducted in spontaneously breathing healthy volunteers with assessment of IVC collapsibility (IVCc) in SC and TH imaging, with measures taken in M-mode or with AI software. We calculated mean bias and limits of agreement (LoA), and the intra-class correlation (ICC) coefficient with their 95% confidence intervals. RESULTS: Sixty volunteers were included; IVC was not visualized in five of them (n = 2, both SC and TH windows, 3.3%; n = 3 in TH approach, 5%). Compared with M-mode, AI showed good accuracy both for SC (IVCc: bias - 0.7%, LoA [- 24.9; 23.6]) and TH approach (IVCc: bias 3.7%, LoA [- 14.9; 22.3]). The ICC coefficients showed moderate reliability: 0.57 [0.36; 0.73] in SC, and 0.72 [0.55; 0.83] in TH. Comparing anatomical sites (SC vs TH), results produced by M-mode were not interchangeable (IVCc: bias 13.9%, LoA [- 18.1; 45.8]). When this evaluation was performed with AI, such difference became smaller: IVCc bias 7.7%, LoA [- 19.2; 34.6]. The correlation between SC and TH assessments was poor for M-mode (ICC = 0.08 [- 0.18; 0.34]) while moderate for AI (ICC = 0.69 [0.52; 0.81]). CONCLUSIONS: The use of AI shows good accuracy when compared with the traditional M-mode IVC assessment, both for SC and TH imaging. Although AI reduces differences between sagittal and coronal IVC measurements, results from these sites are not interchangeable.

Full and simplified assessment of left ventricular diastolic function in covid-19 patients admitted to ICU: Feasibility, incidence, and association with mortality.

PURPOSE: Left ventricular diastolic dysfunction (LVDD) is associated with poor outcomes in the intensive care unit (ICU). Nonetheless, precise reporting of LVDD in COVID-19 patients is currently lacking and assessment could be challenging. METHODS: We performed an echocardiography study in COVID-19 patients admitted to ICU with the aim to describe the feasibility of full or simplified LVDD assessment and its incidence. We also evaluated the association of LVDD or of single echocardiographic parameters with hospital mortality. RESULTS: Between 06.10.2020 and 18.02.2021, full diastolic assessment was feasible in 74% (n = 26/35) of patients receiving a full echocardiogram study. LVDD incidence was 46% (n = 12/26), while the simplified assessment produced different results (incidence 81%, n = 21/26). Nine patients with normal function on full assessment had LVDD with simplified criteria (grade I = 2; grade II = 3; grade III = 4). Nine patients were hospital-survivors (39%); the incidence of LVDD (full assessment) was not different between survivors (n = 2/9, 22%) and non-survivors (n = 10/17, 59%; p = .11). The E/e' ratio lateral was lower in survivors (7.4 [3.6] vs. non-survivors 10.5 [6.3], p = .03). We also found that s' wave was higher in survivors (average, p = .01). CONCLUSION: In a small single-center study, assessment of LVDD according to the latest guidelines was feasible in three quarters of COVID-19 patients. Non-survivors showed a trend toward greater LVDD incidence; moreover, they had significantly worse s' values (all) and higher E/e' ratio (lateral).

Use of ketamine in patients with refractory severe asthma exacerbations: systematic review of prospective studies.

PURPOSE: Asthma is a heterogeneous disease with a wide range of symptoms. Severe asthma exacerbations (SAEs) are characterized by worsening symptoms and bronchospasm requiring emergency department visits. In addition to conventional strategies for SAEs (inhaled ß-agonists, anticholinergics, and systemic corticosteroids), another pharmacological option is represented by ketamine. We performed a systematic review to explore the role of ketamine in refractory SAEs. METHODS: We performed a systematic search on PubMed and EMBASE up to August 12th, 2021. We selected prospective studies only, and outcomes of interest were oxygenation/respiratory parameters, clinical status, need for invasive ventilation and effects on weaning. RESULTS: We included a total of seven studies, five being randomized controlled trials (RCTs, population range 44-92 patients). The two small prospective studies (n = 10 and n = 11) did not have a control group. Four studies focused on adults, and three enrolled a pediatric population. We found a large heterogeneity regarding sample size, age and gender distribution, inclusion criteria (different severity scores, if any) and ketamine dosing (bolus and/or continuous infusion). Of the five RCTs, three compared ketamine to placebo, while one used fentanyl and the other aminophylline. The outcomes evaluated by the included studies were highly variable. Despite paucity of data and large heterogeneity, an overview of the included studies suggests absence of clear benefit produced by ketamine in patients with refractory SAE, and some signals towards side effects. CONCLUSION: Our systematic review does not support the use of ketamine in refractory SAE. A limited number of prospective studies with large heterogeneity was found. Well-designed multicenter RCTs are desirable.

Agreement between subcostal and transhepatic longitudinal imaging of the inferior vena cava for the evaluation of fluid responsiveness: A systematic review.

PURPOSE: Assessment of fluid-responsiveness is a key aspect of daily management in critically ill patients. Non-invasive evaluation of the variation of inferior vena cava (IVC) diameter during ventilation may provide useful information. However, a standard sagittal IVC visualization from the subcostal (SC) region is not always feasible. An alternative method to visualize the IVC is a coronal trans-hepatic (TH) approach. MATERIALS AND METHODS: We performed a systematic search to explore the interchangeability of IVC evaluation with SC and TH views. We searched Medline and EMBASE to identify prospective studies. We did not consider the relationship between axial and sagittal visualization of the IVC. RESULTS: We included seven studies reporting data on IVC evaluation with both SC and TH IVC views. Four studies were conducted on spontaneously breathing patients/volunteers, two on fully mechanically ventilated patients, and one in a mixed population, with large heterogeneity regarding the analyses reported. Limits of agreement between SC and TH were large. Concordance of the IVC collapsibility/distensibility indices are not interchangeable between SC and TH view. Correlation between diameters measured with SC and TH approach and intra/inter-observer correlation produced variable results. CONCLUSIONS: An overview of the included studies suggests that longitudinal TH and SC assessment of IVC size and respiratory variation are not interchangeable. New studies with accurate data reporting and appropriate statistical analysis are needed to define proper cut-offs for fluid responsiveness when using TH approach for IVC visualization.

Caution Is Warranted When Assessing Diastolic Function Using Transesophageal Echocardiography. Comment on Kyle et al. Consensus Defined Diastolic Dysfunction and Cardiac Postoperative Morbidity Score: A Prospective Observational Study. J. Clin. Med. 2021, 10, 5198.

Kyle et al. [...].

Use of nafamostat mesilate for anticoagulation during extracorporeal membrane oxygenation: A systematic review.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) represents an advanced option for supporting refractory respiratory and/or cardiac failure. Systemic anticoagulation with unfractionated heparin (UFH) is routinely used. However, patients with bleeding risk and/or heparin-related side effects may necessitate alternative strategies: among these, nafamostat mesilate (NM) has been reported. METHODS: We conducted a systematic literature search (PubMed and EMBASE, updated 12/08/2021), including all studies reporting NM anticoagulation for ECMO. We focused on reasons for starting NM, its dose and the anticoagulation monitoring approach, the incidence of bleeding/thrombosis complications, the NM-related side effects, ECMO weaning, and mortality. RESULTS: The search revealed 11 relevant findings, all with retrospective design. Of these, three large studies reported a control group receiving UFH, the other were case series (n = 3) or case reports (n = 5). The main reason reported for NM use was an ongoing or high risk of bleeding. The NM dose varied largely as did the anticoagulation monitoring approach. The average NM dose ranged from 0.46 to 0.67 mg/kg/h, but two groups of authors reported larger doses when monitoring anticoagulation with ACT. Conflicting findings were found on bleeding and thrombosis. The only NM-related side effect was hyperkalemia (n = 2 studies) with an incidence of 15%-18% in patients anticoagulated with NM. Weaning and survival varied across studies. CONCLUSION: Anticoagulation with NM in ECMO has not been prospectively studied. While several centers have experience with this approach in high-risk patients, prospective studies are warranted to establish the optimal space of this approach in ECMO.

The effects of exposure to severe hyperoxemia on neurological outcome and mortality after cardiac arrest.

INTRODUCTION: Hyperoxemia during cardiac arrest (CA) may increase chances of successful resuscitation. However, episodes of severe hyperoxemia after intensive care unit admission occurs frequently (up to 60%), and these have been associated with higher mortality in CA patients. The impact of severe hyperoxemia on neurological outcome is more unclear. EVIDENCE ACQUISITION: We conducted a systematic review and meta-analysis on Pubmed and EMBASE to evaluate the effects of severe hyperoxemia according to arterial blood gas analysis on neurological outcome and mortality in patients resuscitated from CA and admitted to intensive care unit. EVIDENCE SYNTHESIS: Thirteen observational studies were included, eight of them reporting data on neurological outcome and ten on mortality. Most studies reported odds ratio adjusted for confounders. Severe hyperoxemia was associated with worse neurological outcome (OR 1.37 [95%CI 1.01,1.86], P=0.04) and higher mortality at longest follow-up (OR 1.32 [95%CI 1.11,1.57], P=0.002). Subgroup analyses according to timing of hyperoxemia showed that any hyperoxemia during the first 36 hours was associated with worse neurological outcome (OR 1.52 [95%CI 1.12,2.08], P=0.008) and higher mortality (OR 1.40 [95%CI 1.18,1.66], P=0.0001), whilst early hyperoxemia was not (neurological: P=0.29; mortality: P=0.19). Sensitivity analyses mostly confirmed the results of the primary analyses. CONCLUSIONS: Severe hyperoxemia is associated with worse neurological outcome and lower survival in CA survivors admitted to intensive care unit. Clinical efforts should be made to avoid severe hyperoxemia during at least the first 36 hours after cardiac arrest.

Targeted Temperature Management after Cardiac Arrest: A Systematic Review and Meta-Analysis with Trial Sequential Analysis.

Target temperature management (TTM) in cardiac arrest (CA) survivors is recommended after hospital admission for its possible beneficial effects on survival and neurological outcome. Whether a lower target temperature (i.e., 32-34 °C) improves outcomes is unclear. We conducted a systematic review and meta-analysis on Pubmed and EMBASE to evaluate the effects on mortality and neurologic outcome of TTM at 32-34 °C as compared to controls (patients cared with "actively controlled" or "uncontrolled" normothermia). Results were analyzed via risk ratios (RR) and 95% confidence intervals (CI). Eight randomized controlled trials (RCTs) were included. TTM at 32-34 °C was compared to "actively controlled" normothermia in three RCTs and to "uncontrolled" normothermia in five RCTs. TTM at 32-34 °C does not improve survival as compared to normothermia (RR:1.06 (95%CI 0.94, 1.20), p = 0.36; I2 = 39%). In the subgroup analyses, TTM at 32-34 °C is associated with better survival when compared to "uncontrolled" normothermia (RR: 1.31 (95%CI 1.07, 1.59), p = 0.008) but shows no beneficial effects when compared to "actively controlled" normothermia (RR: 0.97 (95%CI 0.90, 1.04), p = 0.41). TTM at 32-34 °C does not improve neurological outcome as compared to normothermia (RR: 1.17 (95%CI 0.97, 1.41), p = 0.10; I2 = 60%). TTM at 32-34 °C increases the risk of arrhythmias (RR: 1.35 (95%CI 1.16, 1.57), p = 0.0001, I2 = 0%). TTM at 32-34 °C does not improve survival nor neurological outcome after CA and increases the risk of arrhythmias.

Cerebral regional oxygen saturation during cardiopulmonary resuscitation and return of spontaneous circulation: A systematic review and meta-analysis.

AIM: Predicting the return of spontaneous circulation (ROSC) during cardiopulmonary resuscitation in victims of cardiac arrest (CA) remains challenging. Cerebral regional oxygen saturation (rSO2) measured during resuscitation is feasible, and higher initial and overall values seem associated with ROSC. However, these observations were limited to the analysis of few small single-centre studies. There is a growing number of studies evaluating the role of cerebral rSO2 in the prediction of ROSC. METHODS: We conducted an updated meta-analysis aimed at investigating the association of initial and overall values of cerebral rSO2 with ROSC after CA. We performed subgroups analyses according to the location of CA and conducted a secondary analysis according to the country where the study was conducted (resuscitation practice varies greatly for out-of-hospital CA). RESULTS: We included 17 studies. Higher initial rSO2 values (11 studies, n = 2870, 16.6% achieved ROSC) were associated with ROSC: Mean Difference (MD) -11.54 [95%Confidence Interval (CI)-20.96, -2.12]; p = 0.02 (I2 = 97%). The secondary analysis confirmed this finding when pooling together European and USA studies, but did not for Japanese studies (p = 0.06). One multi-centre Japanese study was an outlier with large influence on 95%CI. Higher overall rSO2 values during resuscitation (9 studies, n = 894, 33.7% achieving ROSC) were associated with ROSC: MD-10.38; [-13.73, -7.03]; p < 0.00001 (I2 = 77%). All studies were conducted in Europe/USA. CONCLUSIONS: This updated meta-analysis confirmed the association between higher initial and overall values of cerebral rSO2 and ROSC after CA. However, we found geographical differences, since this association was not present when Japanese studies were analysed separately.

Epidural analgesia during labour and stress markers in the newborn.

Labour and modes of delivery can influence the plasma levels of stress hormones and cytokines involved in pathophysiologic cascade, potentially damaging brain development of the newborn. This prospective observational, single-centre, case-control, non-profit study aimed to detect potential differences in foetal well-being such as stress neuroendocrine responses. Quantitative determinations of the stress markers interleukin (IL)-1ß, IL-8, and ß-endorphin were compared between the control group and the epidural analgesia group. We found higher IL1-ß levels but lower IL-8 and ß-endorphin levels in the epidural analgesia group than in the control group. No significant inter-group differences were observed for any parameters. Our findings demonstrate that epidural analgesia for pain relief during labour does not result in significant differences in blood stress response markers.IMPACT STATEMENTWhat is already known on this subject? We already know that plasma levels of stress hormones and cytokines are influenced by labour and delivery modes. This has a deep impact on the newborn in terms of brain damage, immune system deficits, and altered hypothalamic-pituitary axis responses. We also know that epidural analgesia is a widespread practice that offers pain relief to the woman in labour, but there are few studies on the potentially negative effects of epidural labour analgesia on the unborn child.What do the results of this study add? This study found no significative differences in blood stress response markers between the epidural analgesia group and the control group. Under this study circumstances we found out that epidural analgesia does not significantly influence the newborn's well-being during labour and delivery.What are the implications of these findings for clinical practice and/or further research? These findings must be confirmed by further studies to verify whether epidural analgesia is safe for the newborn's development.

Prevalence of burnout among intensive care physicians: a systematic review. / Prevalência de burnout entre médicos atuantes em terapia intensiva: uma revisão sistemática.

OBJECTIVE: We performed a systematic review to summarize the knowledge regarding the prevalence of burnout among intensive care unit physicians. METHODS: We conducted a systematic review of the MEDLINE and PubMed® databases (last update 04.02.2019) with the goal of summarizing the evidence on burnout among intensive care unit physicians. We included all studies reporting burnout in intensive care unit personnel according to the Maslach Burnout Inventory questionnaire and then screened studies for data on burnout among intensive care unit physician specifically. RESULTS: We found 31 studies describing burnout in intensive care unit staff and including different healthcare profiles. Among these, 5 studies focused on physicians only, and 12 others investigated burnout in mixed intensive care unit personnel but provided separate data on physicians. The prevalence of burnout varied greatly across studies (range 18% - 49%), but several methodological discrepancies, among them cut-off criteria for defining burnout and variability in the Likert scale, precluded a meaningful pooled analysis. CONCLUSION: The prevalence of burnout syndrome among intensive care unit physicians is relatively high, but significant methodological heterogeneities warrant caution being used in interpreting our results. The lower reported levels of burnout seem higher than those found in studies investigating mixed intensive care unit personnel. There is an urgent need for consensus recommending a consistent use of the Maslach Burnout Inventory test to screen burnout, in order to provide precise figures on burnout in intensive care unit physicians.

OBJETIVO: Realizar uma revisão sistemática para sumarizar o conhecimento relativo à prevalência de burnout entre médicos atuantes na unidade de terapia intensiva. MÉTODOS: Conduzimos uma revisão sistemática nas bases de dados MEDLINE e PubMed® (última atualização em 4 de fevereiro de 2019), com o objetivo de resumir a evidência a respeito de burnout entre médicos atuantes em unidades de terapia intensiva. Incluímos todos os estudos que relatavam burnout em trabalhadores na unidade de terapia intensiva, segundo o Inventário de Burnout de Maslach e, a seguir, triamos os estudos quanto a dados relativos a burnout especificamente em médicos atuantes na unidade de terapia intensiva. RESULTADOS: Encontramos 31 estudos que descreviam burnout em membros da equipe da unidade de terapia intensiva e incluíam diferentes perfis de profissionais de saúde. Dentre estes, cinco estudos se focalizavam apenas em médicos, e 12 outros investigavam burnout em uma mescla de profissionais atuantes na unidade de terapia intensiva, mas forneciam dados à parte relativos aos médicos. A prevalência de burnout teve grande variação entre os estudos (variando entre 18% e 49%), porém diversas discrepâncias metodológicas, dentre elas os critérios de corte para definição de burnout e variabilidade da escala de Likert, impediram uma análise agrupada significativa. CONCLUSÃO: A prevalência da síndrome de burnout entre médicos atuantes na unidade de terapia intensiva é relativamente alta, porém heterogeneidades metodológicas significantes exigem precauções na interpretação de nossos resultados. Os níveis mais baixos de burnout relatados parecem mais elevados do que os identificados em estudos que investigaram uma mescla de profissionais da unidade de terapia intensiva. Há uma necessidade urgente de consenso que recomende o uso consistente do Inventário de Burnout de Maslach para triar a presença de burnout a fim de fornecer dados precisos a respeito de burnout entre médicos atuantes na unidade de terapia intensiva.

Prevalência de burnout entre médicos atuantes em terapia intensiva: uma revisão sistemática / Prevalence of burnout among intensive care physicians: a systematic review

RESUMO Objetivo: Realizar uma revisão sistemática para sumarizar o conhecimento relativo à prevalência de burnout entre médicos atuantes na unidade de terapia intensiva. Métodos: Conduzimos uma revisão sistemática nas bases de dados MEDLINE e PubMed® (última atualização em 4 de fevereiro de 2019), com o objetivo de resumir a evidência a respeito de burnout entre médicos atuantes em unidades de terapia intensiva. Incluímos todos os estudos que relatavam burnout em trabalhadores na unidade de terapia intensiva, segundo o Inventário de Burnout de Maslach e, a seguir, triamos os estudos quanto a dados relativos a burnout especificamente em médicos atuantes na unidade de terapia intensiva. Resultados: Encontramos 31 estudos que descreviam burnout em membros da equipe da unidade de terapia intensiva e incluíam diferentes perfis de profissionais de saúde. Dentre estes, cinco estudos se focalizavam apenas em médicos, e 12 outros investigavam burnout em uma mescla de profissionais atuantes na unidade de terapia intensiva, mas forneciam dados à parte relativos aos médicos. A prevalência de burnout teve grande variação entre os estudos (variando entre 18% e 49%), porém diversas discrepâncias metodológicas, dentre elas os critérios de corte para definição de burnout e variabilidade da escala de Likert, impediram uma análise agrupada significativa. Conclusão: A prevalência da síndrome de burnout entre médicos atuantes na unidade de terapia intensiva é relativamente alta, porém heterogeneidades metodológicas significantes exigem precauções na interpretação de nossos resultados. Os níveis mais baixos de burnout relatados parecem mais elevados do que os identificados em estudos que investigaram uma mescla de profissionais da unidade de terapia intensiva. Há uma necessidade urgente de consenso que recomende o uso consistente do Inventário de Burnout de Maslach para triar a presença de burnout a fim de fornecer dados precisos a respeito de burnout entre médicos atuantes na unidade de terapia intensiva.

Abstract Objective: We performed a systematic review to summarize the knowledge regarding the prevalence of burnout among intensive care unit physicians. Methods: We conducted a systematic review of the MEDLINE and PubMed® databases (last update 04.02.2019) with the goal of summarizing the evidence on burnout among intensive care unit physicians. We included all studies reporting burnout in intensive care unit personnel according to the Maslach Burnout Inventory questionnaire and then screened studies for data on burnout among intensive care unit physician specifically. Results: We found 31 studies describing burnout in intensive care unit staff and including different healthcare profiles. Among these, 5 studies focused on physicians only, and 12 others investigated burnout in mixed intensive care unit personnel but provided separate data on physicians. The prevalence of burnout varied greatly across studies (range 18% - 49%), but several methodological discrepancies, among them cut-off criteria for defining burnout and variability in the Likert scale, precluded a meaningful pooled analysis. Conclusion: The prevalence of burnout syndrome among intensive care unit physicians is relatively high, but significant methodological heterogeneities warrant caution being used in interpreting our results. The lower reported levels of burnout seem higher than those found in studies investigating mixed intensive care unit personnel. There is an urgent need for consensus recommending a consistent use of the Maslach Burnout Inventory test to screen burnout, in order to provide precise figures on burnout in intensive care unit physicians.