Weaning from mechanical ventilation in intensive care units across 50 countries (WEAN SAFE): a multicentre, prospective, observational cohort study

BACKGROUND

Current management practices and outcomes in weaning from invasive mechanical ventilation are poorly understood. We aimed to describe the epidemiology, management, timings, risk for failure, and outcomes of weaning in patients requiring at least 2 days of invasive mechanical ventilation.

METHODS

WEAN SAFE was an international, multicentre, prospective, observational cohort study done in 481 intensive care units in 50 countries. Eligible participants were older than 16 years, admitted to a participating intensive care unit, and receiving mechanical ventilation for 2 calendar days or longer. We defined weaning initiation as the first attempt to separate a patient from the ventilator, successful weaning as no reintubation or death within 7 days of extubation, and weaning eligibility criteria based on positive end-expiratory pressure, fractional concentration of oxygen in inspired air, and vasopressors. The primary outcome was the proportion of patients successfully weaned at 90 days. Key secondary outcomes included weaning duration, timing of weaning events, factors associated with weaning delay and weaning failure, and hospital outcomes. This study is registered with ClinicalTrials.gov, NCT03255109.

FINDINGS

Between Oct 4, 2017, and June 25, 2018, 10 232 patients were screened for eligibility, of whom 5869 were enrolled. 4523 (77·1%) patients underwent at least one separation attempt and 3817 (65·0%) patients were successfully weaned from ventilation at day 90. 237 (4·0%) patients were transferred before any separation attempt, 153 (2·6%) were transferred after at least one separation attempt and not successfully weaned, and 1662 (28·3%) died while invasively ventilated. The median time from fulfilling weaning eligibility criteria to first separation attempt was 1 day (IQR 0-4), and 1013 (22·4%) patients had a delay in initiating first separation of 5 or more days. Of the 4523 (77·1%) patients with separation attempts, 2927 (64·7%) had a short wean (≤1 day), 457 (10·1%) had intermediate weaning (2-6 days), 433 (9·6%) required prolonged weaning (≥7 days), and 706 (15·6%) had weaning failure. Higher sedation scores were independently associated with delayed initiation of weaning. Delayed initiation of weaning and higher sedation scores were independently associated with weaning failure. 1742 (31·8%) of 5479 patients died in the intensive care unit and 2095 (38·3%) of 5465 patients died in hospital.

INTERPRETATION

In critically ill patients receiving at least 2 days of invasive mechanical ventilation, only 65% were weaned at 90 days. A better understanding of factors that delay the weaning process, such as delays in weaning initiation or excessive sedation levels, might improve weaning success rates.

FUNDING

European Society of Intensive Care Medicine, European Respiratory Society.

Frailty is associated with long-term outcome in patients with sepsis who are over 80 years old: results from an observational study in 241 European ICUs

BACKGROUND

Sepsis is one of the most frequent reasons for acute intensive care unit (ICU) admission of very old patients and mortality rates are high. However, the impact of pre-existing physical and cognitive function on long-term outcome of ICU patients ≥ 80 years old (very old intensive care patients (VIPs)) with sepsis is unclear.

OBJECTIVE

To investigate both the short- and long-term mortality of VIPs admitted with sepsis and assess the relation of mortality with pre-existing physical and cognitive function.

DESIGN

Prospective cohort study.

SETTING

241 ICUs from 22 European countries in a six-month period between May 2018 and May 2019.

SUBJECTS

Acutely admitted ICU patients aged ≥80 years with sequential organ failure assessment (SOFA) score ≥ 2.

METHODS

Sepsis was defined according to the sepsis 3.0 criteria. Patients with sepsis as an admission diagnosis were compared with other acutely admitted patients. In addition to patients' characteristics, disease severity, information about comorbidity and polypharmacy and pre-existing physical and cognitive function were collected.

RESULTS

Out of 3,596 acutely admitted VIPs with SOFA score ≥ 2, a group of 532 patients with sepsis were compared to other admissions. Predictors for 6-month mortality were age (per 5 years): Hazard ratio (HR, 1.16 (95% confidence interval (CI), 1.09-1.25, P < 0.0001), SOFA (per one-point): HR, 1.16 (95% CI, 1.14-1.17, P < 0.0001) and frailty (CFS > 4): HR, 1.34 (95% CI, 1.18-1.51, P < 0.0001).

CONCLUSIONS

There is substantial long-term mortality in VIPs admitted with sepsis. Frailty, age and disease severity were identified as predictors of long-term mortality in VIPs admitted with sepsis.

Saving Blood and Reducing Costs: Updating Blood Transfusion Practice in Lower Limb Arthroplasty

Aim Our aim was to quantify blood transfusion rates in lower limb arthroplasty following the introduction of a multimodal enhanced recovery programme (ERP). We then sought to update the maximum surgical blood ordering schedule (MSBOS) and calculate cost savings achieved. Methods A retrospective cohort study was conducted of all patients who required blood transfusion following primary and revision total hip and knee arthroplasty in 2012 and 2015. A multimodal ERP was introduced in 2015. Cost savings were calculated following the introduction of a new MSBOS. Results During the two-year study period 1467 lower limb arthroplasty procedures were performed. The cross-match to transfusion ratio was 3.6:1 in 2012 and 9.9:1 in 2015. The updated MSBOS resulted in a 46% reduction of cross-matched blood and savings of €54,375 per annum. Conclusion Improved perioperative management in lower limb arthroplasty has reduced blood transfusion rates. Updating blood transfusion practice can result in considerable savings in blood, resources and costs.

Spinal cord infarction as a rare complication of fat embolism syndrome following bilateral intramedullary nailing of femur fractures

Fat embolism syndrome (FES) is a rare and potentially fatal complication occurring most often after long bone or pelvic fractures and orthopaedic procedures. It can consist of pulmonary, central nervous system and cutaneous manifestations. The exact pathophysiology of emboli reaching the arterial circulation is poorly understood.1 It is suggested that this may occur by either 'paradoxical' embolism or microembolism.2 3 Its true incidence is unknown but increases in the presence of multiple closed fractures. It can be a diagnostic dilemma for clinicians and if suspected diffusion-weighted MRI is the modality of choice for the investigation of the central nervous system.4 We present the case of a 22-year-old man who developed multifocal cerebral infarcts, a right-sided cerebellar infarct and an infarct in the anterior cord bilaterally at the level of C5-C6 as a result of FES.

Airway complications in infants: comparison of laryngeal mask airway and the facemask-oral airway

PURPOSE

To compare the incidence of airway complications in children less than one year of age whose airways were maintained during anesthesia with either a laryngeal mask airway (LMA) or a facemask and oral airway (FM-OA).

METHODS

We randomized 49 - ASA class 1&2 - infants to an LMA or FM-OA group. All infants were undergoing minor general, urological or orthopedic procedures. Anesthesia was induced and maintained with halothane in nitrous oxide 50% and oxygen. The airway was removed in both groups when the infant was awake. The occurrence of airway complications (breath-holding, coughing, laryngospasm, secretions, obstruction and oxygen saturation < 95%) at induction of anesthesia, intraoperatively and during emergence from anesthesia was recorded.

RESULTS

Airway complications occurred perioperaively in 15 of 27 infants in the LMA group and in 5 of 22 infants in the FM-OA group (P: 0.02).

CONCLUSION

In infants, the use of the LMA is associated with an increased incidence of airway complications compared with the use of the FM-OA.

Acute pernicious (sho-shin) beri-beri: a report of three cases

Acute pernicious or sho-shin beri-beri is characterised by haemodynamic and biochemical features which include hypotension, high cardiac output, low peripheral vascular resistance, lactic acidosis and high mixed venous content. The disorder is a metabolic emergency and requires immediate treatment with intravenous thiamine. Three cases are described which were successfully treated with intravenous thiamine (500 mg intravenously, followed by 100 mg 8-hourly for 24 hours then 100 mg daily) without using catecholamines or sodium bicarbonate. Digoxin was used in two cases to manage cardiac dysfunction which was poorly responsive to thiamine.

The anaesthetic management of the child with Eisenmenger's syndrome

There is little clinical data in the literature on the anaesthetic management of paediatric patients with Eisenmenger's syndrome undergoing non-cardiac surgery. This paper reviews our experiences with either such patients who underwent a total of 11 surgical procedures. Of the eight children, six had Down's syndrome and an atrio-ventricular septal defect, one had a ventricular septal defect and one an atrial septal defect. Nine of the eleven operations consisted of minor dental, plastic or ENT procedures, while one patient underwent two laparotomies. Premedication (trimeprazine/ meperidine combination or midazolam) was administered on three occasions. Induction of anaesthesia was achieved by either inhalation of halothane (2), or intravenously with thiopentone (6), ketamine (2) or propofol (1). Muscle relaxation and mechanical ventilation were employed only for both intra-abdominal procedures, otherwise patients were allowed to breathe spontaneously with, or without, manual assistance. Halothane (8), isoflurane (2) and enflurane (1) were all used for maintenance of anaesthesia. Non-invasive monitoring was applied intraoperatively for minor procedures, and arterial and central venous catheters inserted for the laparotomies. Postoperative analgesia for both these cases was provided by an epidural infusion of bupivacaine 0.125% and fentanyl 5 micrograms x ml(-1). A single im bolus of morphine was required following a dental clearance, otherwise pain relief for the rest of the cases was achieved by local anaesthetic infiltration and NSAIDS. With the exception of a single episode of bradycardia, induction, maintenance and recovery from anaesthesia were well tolerated in all cases. In conclusion, our experience suggests that despite theoretical risks, children with Eisenmenger's syndrome appear to tolerate a variety of anaesthetic techniques.