Dynamic prediction of mortality in COVID-19 patients in the intensive care unit: A retrospective multi-center cohort study.

Background: The COVID-19 pandemic continues to overwhelm intensive care units (ICUs) worldwide, and improved prediction of mortality among COVID-19 patients could assist decision making in the ICU setting. In this work, we report on the development and validation of a dynamic mortality model specifically for critically ill COVID-19 patients and discuss its potential utility in the ICU. Methods: We collected electronic medical record (EMR) data from 3222 ICU admissions with a COVID-19 infection from 25 different ICUs in the Netherlands. We extracted daily observations of each patient and fitted both a linear (logistic regression) and non-linear (random forest) model to predict mortality within 24 h from the moment of prediction. Isotonic regression was used to re-calibrate the predictions of the fitted models. We evaluated the models in a leave-one-ICU-out (LOIO) cross-validation procedure. Results: The logistic regression and random forest model yielded an area under the receiver operating characteristic curve of 0.87 [0.85; 0.88] and 0.86 [0.84; 0.88], respectively. The recalibrated model predictions showed a calibration intercept of -0.04 [-0.12; 0.04] and slope of 0.90 [0.85; 0.95] for logistic regression model and a calibration intercept of -0.19 [-0.27; -0.10] and slope of 0.89 [0.84; 0.94] for the random forest model. Discussion: We presented a model for dynamic mortality prediction, specifically for critically ill COVID-19 patients, which predicts near-term mortality rather than in-ICU mortality. The potential clinical utility of dynamic mortality models such as benchmarking, improving resource allocation and informing family members, as well as the development of models with more causal structure, should be topics for future research.

Can we reliably automate clinical prognostic modelling? A retrospective cohort study for ICU triage prediction of in-hospital mortality of COVID-19 patients in the Netherlands.

BACKGROUND: Building Machine Learning (ML) models in healthcare may suffer from time-consuming and potentially biased pre-selection of predictors by hand that can result in limited or trivial selection of suitable models. We aimed to assess the predictive performance of automating the process of building ML models (AutoML) in-hospital mortality prediction modelling of triage COVID-19 patients at ICU admission versus expert-based predictor pre-selection followed by logistic regression. METHODS: We conducted an observational study of all COVID-19 patients admitted to Dutch ICUs between February and July 2020. We included 2,690 COVID-19 patients from 70 ICUs participating in the Dutch National Intensive Care Evaluation (NICE) registry. The main outcome measure was in-hospital mortality. We asessed model performance (at admission and after 24h, respectively) of AutoML compared to the more traditional approach of predictor pre-selection and logistic regression. FINDINGS: Predictive performance of the autoML models with variables available at admission shows fair discrimination (average AUROC = 0·75-0·76 (sdev = 0·03), PPV = 0·70-0·76 (sdev = 0·1) at cut-off = 0·3 (the observed mortality rate), and good calibration. This performance is on par with a logistic regression model with selection of patient variables by three experts (average AUROC = 0·78 (sdev = 0·03) and PPV = 0·79 (sdev = 0·2)). Extending the models with variables that are available at 24h after admission resulted in models with higher predictive performance (average AUROC = 0·77-0·79 (sdev = 0·03) and PPV = 0·79-0·80 (sdev = 0·10-0·17)). CONCLUSIONS: AutoML delivers prediction models with fair discriminatory performance, and good calibration and accuracy, which is as good as regression models with expert-based predictor pre-selection. In the context of the restricted availability of data in an ICU quality registry, extending the models with variables that are available at 24h after admission showed small (but significantly) performance increase.

Comparison of outcome and characteristics between 6343 COVID-19 patients and 2256 other community-acquired viral pneumonia patients admitted to Dutch ICUs.

PURPOSE: Describe the differences in characteristics and outcomes between COVID-19 and other viral pneumonia patients admitted to Dutch ICUs. MATERIALS AND METHODS: Data from the National-Intensive-Care-Evaluation-registry of COVID-19 patients admitted between February 15th and January 1th 2021 and other viral pneumonia patients admitted between January 1st 2017 and January 1st 2020 were used. Patients' characteristics, the unadjusted, and adjusted in-hospital mortality were compared. RESULTS: 6343 COVID-19 and 2256 other viral pneumonia patients from 79 ICUs were included. The COVID-19 patients included more male (71.3 vs 49.8%), had a higher Body-Mass-Index (28.1 vs 25.5), less comorbidities (42.2 vs 72.7%), and a prolonged hospital length of stay (19 vs 9 days). The COVID-19 patients had a significantly higher crude in-hospital mortality rate (Odds ratio (OR) = 1.80), after adjustment for patient characteristics and ICU occupancy rate the OR was respectively 3.62 and 3.58. CONCLUSION: Higher mortality among COVID-19 patients could not be explained by patient characteristics and higher ICU occupancy rates, indicating that COVID-19 is more severe compared to other viral pneumonia. Our findings confirm earlier warnings of a high need of ICU capacity and high mortality rates among relatively healthy COVID-19 patients as this may lead to a higher mental workload for the staff.

Short-term outpatient follow-up of COVID-19 patients: A multidisciplinary approach.

BACKGROUND: Short-term follow-up of COVID-19 patients reveals pulmonary dysfunction, myocardial damage and severe psychological distress. Little is known of the burden of these sequelae, and there are no clear recommendations for follow-up of COVID-19 patients.In this multi-disciplinary evaluation, cardiopulmonary function and psychological impairment after hospitalization for COVID-19 are mapped. METHODS: We evaluated patients at our outpatient clinic 6 weeks after discharge. Cardiopulmonary function was measured by echocardiography, 24-hours ECG monitoring and pulmonary function testing. Psychological adjustment was measured using questionnaires and semi-structured clinical interviews. A comparison was made between patients admitted to the general ward and Intensive care unit (ICU), and between patients with a high versus low functional status. FINDINGS: Eighty-one patients were included of whom 34 (41%) had been admitted to the ICU. New York Heart Association class II-III was present in 62% of the patients. Left ventricular function was normal in 78% of patients. ICU patients had a lower diffusion capacity (mean difference 12,5% P = 0.01), lower forced expiratory volume in one second and forced vital capacity (mean difference 14.9%; P<0.001; 15.4%; P<0.001; respectively). Risk of depression, anxiety and PTSD were 17%, 5% and 10% respectively and similar for both ICU and non-ICU patients. INTERPRETATION: Overall, most patients suffered from functional limitations. Dyspnea on exertion was most frequently reported, possibly related to decreased DLCOc. This could be caused by pulmonary fibrosis, which should be investigated in long-term follow-up. In addition, mechanical ventilation, deconditioning, or pulmonary embolism may play an important role.

Detailed immune monitoring of a pregnant woman with critical Covid-19.

A primigravid woman with Covid-19 related respiratory insufficiency was admitted into a tertiary Intensive Care Unit at 23 3/7 weeks' gestation. Highly sensitive flow cytometry of peripheral leukocytes indicated significantly suppressed naïve T- and B-cell compartments. The suppressed immune cell responses led us keep the initially started administration of corticosteroids for fetal and maternal indication at a low dose. After three weeks her B-cell response peaked, SARS-CoV-2 was cleared and clinical improvement ensued a week later. At 28 weeks' gestation, a son of 1570 g was born by cesarean section. She was extubated two days postpartum and discharged from hospital 5.5 weeks postpartum.

Confirmation of the high cumulative incidence of thrombotic complications in critically ill ICU patients with COVID-19: An updated analysis.

INTRODUCTION: We recently reported a high cumulative incidence of thrombotic complications in critically ill patients with COVID-19 admitted to the intensive care units (ICUs) of three Dutch hospitals. In answering questions raised regarding our study, we updated our database and repeated all analyses. METHODS: We re-evaluated the incidence of the composite outcome of symptomatic acute pulmonary embolism (PE), deep-vein thrombosis, ischemic stroke, myocardial infarction and/or systemic arterial embolism in all COVID-19 patients admitted to the ICUs of 2 Dutch university hospitals and 1 Dutch teaching hospital from ICU admission to death, ICU discharge or April 22nd 2020, whichever came first. RESULTS: We studied the same 184 ICU patients as reported on previously, of whom a total of 41 died (22%) and 78 were discharged alive (43%). The median follow-up duration increased from 7 to 14 days. All patients received pharmacological thromboprophylaxis. The cumulative incidence of the composite outcome, adjusted for competing risk of death, was 49% (95% confidence interval [CI] 41-57%). The majority of thrombotic events were PE (65/75; 87%). In the competing risk model, chronic anticoagulation therapy at admission was associated with a lower risk of the composite outcome (Hazard Ratio [HR] 0.29, 95%CI 0.091-0.92). Patients diagnosed with thrombotic complications were at higher risk of all-cause death (HR 5.4; 95%CI 2.4-12). Use of therapeutic anticoagulation was not associated with all-cause death (HR 0.79, 95%CI 0.35-1.8). CONCLUSION: In this updated analysis, we confirm the very high cumulative incidence of thrombotic complications in critically ill patients with COVID-19 pneumonia.

Incidence of thrombotic complications in critically ill ICU patients with COVID-19.

INTRODUCTION: COVID-19 may predispose to both venous and arterial thromboembolism due to excessive inflammation, hypoxia, immobilisation and diffuse intravascular coagulation. Reports on the incidence of thrombotic complications are however not available. METHODS: We evaluated the incidence of the composite outcome of symptomatic acute pulmonary embolism (PE), deep-vein thrombosis, ischemic stroke, myocardial infarction or systemic arterial embolism in all COVID-19 patients admitted to the ICU of 2 Dutch university hospitals and 1 Dutch teaching hospital. RESULTS: We studied 184 ICU patients with proven COVID-19 pneumonia of whom 23 died (13%), 22 were discharged alive (12%) and 139 (76%) were still on the ICU on April 5th 2020. All patients received at least standard doses thromboprophylaxis. The cumulative incidence of the composite outcome was 31% (95%CI 20-41), of which CTPA and/or ultrasonography confirmed VTE in 27% (95%CI 17-37%) and arterial thrombotic events in 3.7% (95%CI 0-8.2%). PE was the most frequent thrombotic complication (n = 25, 81%). Age (adjusted hazard ratio (aHR) 1.05/per year, 95%CI 1.004-1.01) and coagulopathy, defined as spontaneous prolongation of the prothrombin time > 3 s or activated partial thromboplastin time > 5 s (aHR 4.1, 95%CI 1.9-9.1), were independent predictors of thrombotic complications. CONCLUSION: The 31% incidence of thrombotic complications in ICU patients with COVID-19 infections is remarkably high. Our findings reinforce the recommendation to strictly apply pharmacological thrombosis prophylaxis in all COVID-19 patients admitted to the ICU, and are strongly suggestive of increasing the prophylaxis towards high-prophylactic doses, even in the absence of randomized evidence.

Variation in red cell transfusion practice in the intensive care unit - An international survey.

PURPOSE: Unclear recommendations in transfusion guidelines may possibly lead to inconsistency in treatment of patients admitted to the intensive care unit. This study aimed to uncover variation in red blood cell (RBC) transfusion decisions in the ICU worldwide. METHODS: Members of the European Society of Intensive Care Medicine (ESICM) were requested to complete an online questionnaire which included four different hypothetical clinical scenarios. The scenarios represented patients with acute myocardial infarction (AMI), abdominal sepsis, traumatic brain injury (TBI) and post-surgical complications. Hemoglobin level was 7∙3 g/dL in all scenarios. The questionnaire explored the physicians' transfusion decision in each clinical scenario and identified patient characteristics that were most influential in the transfusion decision. RESULTS: In total 211 members participated in the study, of whom 142 (67%) completed the entire survey. Most variation was observed in the clinical scenario of sepsis, in which 49% decided to transfuse and 51% decided not to. In the clinical scenarios of AMI, TBI and post-surgical complications this was respectively; 75/25%, 35/65% and 66/34%. CONCLUSIONS: Critical care physicians differed in outcome of RBC transfusion decisions and weighed patient characteristics differently. These findings indicate that variation in transfusion practice amongst critical care physicians exists.

Predictors of short-term and long-term mortality in critically ill patients admitted to the intensive care unit following allogeneic stem cell transplantation.

Historically, the mortality of patients admitted to the ICU after allogeneic stem cell transplantation (alloSCT) is high. Advancements in transplantation procedures, infectious monitoring and supportive care may have improved the outcome. This study aimed to determine short-term and long-term mortality after ICU admission of patients after alloSCT and to identify prognostic clinical and transplantation-related determinants present at ICU admission for long-term outcome. A multicenter cohort study was performed to determine 30-day and 1-year mortality within 2 years following alloSCT. A total of 251 patients were included. The 30-day and 1-year mortality was 55% and 80%, respectively. Platelet count <25 × 109/L (OR: 2.26, CI: 1.02-5.01) and serum bilirubin >19 µmol/L (OR: 2.47 CI: 1.08-5.65) at admission, other donor than a HLA-matched-related or HLA-matched-unrelated donor (OR: 4.59, CI: 1.49-14.1) and vasoactive medication within 24 h (OR: 2.35, CI: 1.28-4.31) were associated with increased 30-day mortality. Other donor than a HLA-matched-related or HLA-matched-unrelated donor (OR: 1.9, CI: 1.13-3.19), serum bilirubin >77 (OR: 2.05, CI: 1.28-3.30) and vasoactive medication within 24 h (OR: 1.65, CI: 1.12-2.43) were associated with increased 1-year mortality. Neutropenia was associated with decreased 30-day and 1-year mortality (OR: 0.29, CI: 0.14-0.59 and OR: 0.70, CI: 0.48-0.98). Myeloablative conditioning and T cell-depleted transplantation were not associated with increased mortality.

Variation in red cell transfusion decisions in the intensive care unit - a nationwide survey in the Netherlands.

BACKGROUND AND OBJECTIVES: Most guidelines recommend a restrictive transfusion trigger of 7 g/dl. It is unclear whether this resulted in more uniform transfusion practices. The primary objective was to uncover the extent of variation in transfusion decisions within four scenarios of critically ill patients among critical care physicians in the Netherlands. MATERIALS AND METHODS: An online survey comprising four different hypothetical clinical scenarios was sent to all members of the Dutch Society of Intensive Care. The scenarios represented patients with acute myocardial infarction (Hb 8·5 g/dl), abdominal sepsis (Hb 7·1 g/dl), traumatic brain injury (TBI) (Hb 7·9 g/dl) and post-surgical complications (Hb 7·3 g/dl). The questions explored the decision whether or not to transfuse and a ranking of clinical characteristics playing the most important role in the transfusion decision. RESULTS: A total of 224 members (22%) participated in the study of whom 188 (84%) completed all questions. The percentages of respondents that decided to transfuse ranged from 25·9% in the scenario with TBI to 81·6% in the scenario with post-surgical complications. Most controversy was seen in the scenario with sepsis for which 43·2% decided to transfuse, whereas 56·8% decided not to. Haemoglobin level, diagnosis and haemodynamics were most important for the transfusion decision in all scenarios. CONCLUSIONS: Physicians decided differently on red-blood-cell transfusion given the clinical scenarios and weighed clinical characteristics differently in their transfusion decisions. These findings suggest there still is substantial variation in critical care transfusion practice.

[Blood is not for everyone: the usefulness of erythrocyte transfusion]. / Bloed, niet voor iedereen weggelegd: het nut van erytrocytentransfusie.

Increasing evidence on the limited usefulness and the adverse consequences of erythrocyte transfusion has led to a large drop in the number of blood transfusions over the last 20 years. The results of randomised studies suggest that in most haemodynamically stable patients with acute anaemia an Hb transfusion threshold of 4.4 mmol/l for blood transfusion has the same outcomes as a higher transfusion threshold. The effect of blood transfusion in patients with anaemia is not only dependent on their Hb level, but also on other clinical factors that play a role in the balance between oxygen supply and its consumption. The Dutch '4-5-6' rule for indication for blood transfusion takes a number of important clinical factors into account, however, results of recent research suggest that the strict application of this rule will lead to unnecessary transfusions. New research in this area is focused on the quantification of the effect of blood transfusion in various combinations of relevant patient characteristics.

Differences in maternal temperature during labour with remifentanil patient-controlled analgesia or epidural analgesia: a randomised controlled trial.

BACKGROUND: Epidural analgesia and remifentanil patient-controlled analgesia are two popular techniques for the treatment of labour pain, each with its own efficacy and toxicity. METHODS: Parturients requesting analgesia were randomly assigned to either patient-controlled intravenous remifentanil or epidural analgesia. Control patients consisted of parturients not requesting pain medication. The primary objective was to compare the incidence of maternal fever (temperature ⩾ 38°C); secondary outcomes included the incidence of low oxygen saturation, pain scores, nausea and vomiting, sedation scores, pruritus and neonatal outcome. RESULTS: Data from 140 parturients were analysed: 49 received remifentanil analgesia, 49 epidural analgesia and 42 no analgesia (controls). Fever (temperature ⩾ 38°C) developed in 10% of remifentanil patients compared to 37% of epidural patients and 7% of control patients (P<0.001). One or more hypoxaemic events (oxygen saturation <90% for at least 1 min) occurred in 48% of patients on remifentanil versus 15% of patients on epidural analgesia and 20% of control patients (P=0.003). Although pain intensity scores differed significantly between the two groups in favour of the epidural, mean satisfaction scores were similar in both analgesia groups (remifentanil 8.1 ± 1.2 vs. epidural 8.4 ± 1.2). Remifentanil analgesia was associated with a higher incidence of nausea and deeper levels of sedation. The differences in haemodynamic parameters between groups were small and clinically insignificant. CONCLUSIONS: During treatment of labour pain, epidural analgesia is associated with a higher incidence of maternal fever, while remifentanil analgesia results in more frequent and deeper hypoxaemic events.

Fresh frozen plasma transfusion fails to influence the hemostatic balance in critically ill patients with a coagulopathy.

BACKGROUND: Coagulopathy has a high prevalence in critically ill patients. An increased International Normalized Ratio (INR) is a common trigger to transfuse fresh frozen plasma (FFP), even in the absence of bleeding. Therefore, FFP is frequently administered to these patients. However, the efficacy of FFP in correcting hemostatic disorders in non-bleeding recipients has been questioned. OBJECTIVES: To assess whether INR prolongation parallels changes in the results of other tests investigating hemostasis, and to evaluate the coagulant effects of a fixed dose of FFP in non-bleeding critically ill patients with a coagulopathy. METHODS: Markers of coagulation, individual factor levels and levels of natural anticoagulants were measured. Also, thrombin generation and thromboelastometry (ROTEM) assays were performed before and after FFP transfusion (12 mL kg(-1) ) to 38 non-bleeding critically ill patients with an increased INR (1.5-3.0). RESULTS: At baseline, levels of factor II, FV, FVII, protein C, protein S and antithrombin were reduced, and thrombin generation was impaired. ROTEM variables were within reference ranges, except for a prolonged INTEM clot formation time. FFP transfusion increased the levels of coagulation factors (FII, 34% [interquartile range (IQR) 26-46] before vs. 44% [IQR 38-52] after; FV, 48% [IQR 28-76] before vs. 58% [IQR 44-90] after; and FVII, 25% [IQR 16-38] before vs. 37% [IQR 28-55] after), and the levels of anticoagulant proteins. Thrombin generation was unaffected by FFP transfusion (endogenous thrombin potential, 72% [IQR 51-88] before vs. 71% [IQR 42-89] after), whereas ROTEM EXTEM clotting time and maximum clot firmness slightly improved in response to FFP. CONCLUSION: In non-bleeding critically ill patients with a coagulopathy, FFP transfusion failed to induce a more procoagulant state.

Lumbar epidural catheter insertion: the midline vs. the paramedian approach.

BACKGROUND AND OBJECTIVE: The purpose of this study was to compare the characteristics of epidural catheter insertion via the midline or the paramedian approach with regard to ease of catheter insertion, incidence of paraesthesias and efficacy of epidural block. In addition to the type of approach, the prognostic value of Patients characteristics variables with regard to the incidence of paraesthesias was assessed. METHODS: Thirty patients scheduled for surgery under epidural anaesthesia were randomly assigned to one of two groups of 15 patients each. Epidural anaesthesia was performed via a midline or paramedian approach using loss of resistance to saline. Variables measured were: time needed to identify the epidural space, time needed for and ease of epidural catheter insertion and the incidence of paraesthesias. After completion of these observations, epidural anaesthesia was established with 150 mg ropivacaine 1%. Efficacy of the epidural block was assessed by the need for intraoperative analgesics and by the patient on a three-point scale (good/fair/poor). RESULTS: Quality of sensory blockade was adequate in both groups. Catheter insertion was significantly faster using the paramedian approach. The difference between the two approaches with regard to the incidence of paraesthesias was not significant, however, there was a trend towards more paraesthesias in the midline group. In the multivariate analysis, type of approach was an independent significant predictor of paraesthesias and we found a trend towards a higher incidence of paraesthesias in female patients. CONCLUSIONS: Catheter insertion was faster in the paramedian group and we found a trend towards a higher incidence of paraesthesias with the midline approach.

[The abdominal compartment syndrome]. / Het abdominaal compartimentsyndroom.

In two patients, a man aged 67 and a woman aged 80, an abdominal compartment syndrome was diagnosed. The man had been treated surgically for an abdominal aortic aneurysm; he recovered after re-operation. The woman had been treated by sigmoidectomy because of ileus. A Bogota bag and a vacuum-assisted wound-closure system were applied to the abdominal wound. Her condition deteriorated, an intestinal perforation became apparent, of which she did not recover and died. An abdominal compartment syndrome should always be kept in mind when a patient at risk presents with increased intra-abdominal pressure and at least one of the following symptoms: oliguria, decreased cardiac output, increased pulmonary-artery pressure, hypotension and acidosis. Measurement of the bladder pressure remains the method of choice to establish the abdominal pressure level. However, there is a lack of correlation between the measured pressure and the clinical condition of the patient. Therefore, the combination of clinical findings and the observed trend in serial measurements of the bladder pressure is preferred to a single pressure measurement.

Transient neurological symptoms with subarachnoid lidocaine: effect of early mobilization.

BACKGROUND AND OBJECTIVE: Although lidocaine has been used extensively for spinal anaesthesia since 1949, it has been associated with transient neurological symptoms only in the past 10 yr. It has been suggested that early ambulation after spinal anaesthesia, as opposed to traditional 24 h recumbency, might be the causative factor for the development of transient neurological symptoms. The purpose of this study was to examine the effect of early ambulation on the incidence of transient neurological symptoms after single injection spinal anaesthesia with lidocaine 2%. METHODS: Sixty patients undergoing minor surgery under spinal anaesthesia were included. All patients received lidocaine 60 mg. After the establishment of successful subarachnoid block, patients were randomly allocated to two groups of 30 patients. Patients in Group 1 were ambulated as soon as possible, whereas patients in Group 2 were kept recumbent until 6 h after subarachnoid injection. Two days after surgery patients were contacted by a blinded observer and interviewed of transient neurological symptoms using a standardized questionnaire. Patients were asked to express the intensity of pain/discomfort on a verbal rating scale from 0 (no pain) to 10 (worst pain imaginable). RESULTS: There was no significant difference in the incidence of transient neurological symptoms (23% vs. 27%). In all patients, symptoms resolved completely within 6-24 h. The median pain score was 5 (range 2-8) in Group 1 and 7 (range 1-8) in Group 2. CONCLUSIONS: Under the conditions of this study, there is no correlation between the time of ambulation after spinal anaesthesia with lidocaine and the incidence of transient neurological symptoms.

Mortality associated with anaesthesia: a qualitative analysis to identify risk factors.

From a prospectively defined cohort of patients who underwent either general, regional or combined anaesthesia from 1 January 1995 to 1 January 1997 (n = 869 483), all consecutive patients (n = 811) who died within 24 h or remained unintentionally comatose 24 h after anaesthesia were classified to determine a relationship with anaesthesia. These deaths (n = 119; 15%) were further analysed to identify contributing aspects of the anaesthetic management, other factors and the appropriateness of care. The incidence of 24-h peri-operative death per 10 000 anaesthetics was 8.8 (95% CI 8.2-9.5), of peri-operative coma was 0.5 (0.3-0.6) and of anaesthesia-related death 1.4 (1.1-1.6). Of the 119 anaesthesia-related deaths, 62 (52%) were associated with cardiovascular management, 57 (48%) with other anaesthetic management, 12 (10%) with ventilatory management and 12 (10%) with patient monitoring. Inadequate preparation of the patient contributed to 30 (25%) of the anaesthesia-related deaths. During induction of anaesthesia, choice of anaesthetic technique (n = 18 (15%)) and performance of the anaesthesiologist (n = 8 (7%)) were most commonly associated with death. During maintenance, the most common factors were cardiovascular management (n = 43 (36%)), ventilatory management (n = 12 (10%)) and patient monitoring (n = 12 (10%)). In both the recovery and the postoperative phases, patient monitoring was the most common factor (n = 12 (10%) for both). For cardiovascular, ventilatory and other anaesthetic management, human failure contributed to 89 (75%) deaths and organisational factors to 12 (10%). For inadequate patient monitoring, human factors contributed to 71 (60%) deaths and organisational factors to 48 (40%). Other contributing factors were inadequate communication (30 deaths (25%) for all four aspects of the anaesthetic management) and lack of supervision (particularly for ventilatory management). Inadequate care was delivered in 19 (16%) of the anaesthesia-related deaths with respect to cardiovascular management, in 20 (17%) with respect to ventilatory management, in 18 (15%) with respect to patient monitoring and in 23 (19%) with respect to other anaesthetic management.