Performance and usability of pre-operative prediction models for 30-day peri-operative mortality risk: a systematic review.

Estimating pre-operative mortality risk may inform clinical decision-making for peri-operative care. However, pre-operative mortality risk prediction models are rarely implemented in routine clinical practice. High predictive accuracy and clinical usability are essential for acceptance and clinical implementation. In this systematic review, we identified and appraised prediction models for 30-day postoperative mortality in non-cardiac surgical cohorts. PubMed and Embase were searched up to December 2022 for studies investigating pre-operative prediction models for 30-day mortality. We assessed predictive performance in terms of discrimination and calibration. Risk of bias was evaluated using a tool to assess the risk of bias and applicability of prediction model studies. To further inform potential adoption, we also assessed clinical usability for selected models. In all, 15 studies evaluating 10 prediction models were included. Discrimination ranged from a c-statistic of 0.82 (MySurgeryRisk) to 0.96 (extreme gradient boosting machine learning model). Calibration was reported in only six studies. Model performance was highest for the surgical outcome risk tool (SORT) and its external validations. Clinical usability was highest for the surgical risk pre-operative assessment system. The SORT and risk quantification index also scored high on clinical usability. We found unclear or high risk of bias in the development of all models. The SORT showed the best combination of predictive performance and clinical usability and has been externally validated in several heterogeneous cohorts. To improve clinical uptake, full integration of reliable models with sufficient face validity within the electronic health record is imperative.

Quality of recovery after day care surgery with app-controlled remote monitoring: study protocol for a randomized controlled trial.

BACKGROUND: The majority of surgical interventions are performed in day care and patients are discharged after the first critical postoperative period. At home, patients have limited options to contact healthcare providers in the hospital in case of severe pain and nausea. A smartphone application for patients to self-record pain and nausea when at home after day care surgery might improve patient's recovery. Currently patient experiences with smartphone applications are promising; however, we do not know whether remote monitoring with such an application also improves the patient's recovery. This study aims to evaluate the experienced quality of recovery after day care surgery between patients provided with the smartphone application for remote monitoring and patients receiving standard care without remote monitoring. METHODS: This non-blinded randomized controlled trial with mixed methods design will include 310 adult patients scheduled for day care surgery. The intervention group receives the smartphone application with text message function for remote monitoring that enables patients to record pain and nausea. An anaesthesia professional trained in empathetic communication, who will contact the patient in case of severe pain or nausea, performs daily monitoring. The control group receives standard care, with post-discharge verbal and paper instructions. The main study endpoint is the difference in perceived quality of recovery, measured with the QoR-15 questionnaire on the 7th day after day care surgery. Secondary endpoints are the overall score on the Quality of Recovery-15 at day 1, 4 and 7-post discharge, the perceived quality of hospital aftercare and experienced psychological effects of remote monitoring during postoperative recovery from day care surgery. DISCUSSION: This study will investigate if facilitating patients and healthcare professionals with a tool for accessible and empathetic communication might lead to an improved quality of the postoperative recovery period. TRIAL REGISTRATION: The 'Quality of recovery after day care surgery with app-controlled remote monitoring: a randomized controlled trial' is approved and registered on 23 February 2022 by Research Ethics Committees United with registration number R21.076/NL78144.100.21. The protocol NL78144.100.21, 'Quality of recovery after day care surgery with app-controlled remote monitoring: a randomized controlled trial', is registered at the ClinicalTrials.gov public website (registration date 16 February 2022; NCT05244772).

Nurses' experiences with continuous vital sign monitoring on the general surgical ward: a qualitative study based on the Behaviour Change Wheel.

BACKGROUND: To support early recognition of clinical deterioration on a general ward continuous vital signs monitoring (CMVS) systems using wearable devices are increasingly being investigated. Although nurses play a crucial role in successful implementation, reported nurse adoption and acceptance scores vary significantly. In-depth insight into the perspectives of nurses regarding CMVS is lacking. To this end, we applied a theoretical approach for behaviour change derived from the Behaviour Change Wheel (BCW). AIM: To provide insight in the capability, opportunity and motivation of nurses working with CMVS, in order to inform future implementation efforts. METHODS: A qualitative study was conducted, including twelve nurses of a surgical ward in a tertiary teaching hospital with previous experience of working with CMVS. Semi-structured interviews were audiotaped, transcribed verbatim, and analysed using thematic analysis. The results were mapped onto the Capability, Opportunity, Motivation - Behaviour (COM-B) model of the BCW. RESULTS: Five key themes emerged. The theme 'Learning and coaching on the job' linked to Capability. Nurses favoured learning about CVSM by dealing with it in daily practice. Receiving bedside guidance and coaching was perceived as important. The theme 'interpretation of vital sign trends' also linked to Capability. Nurses mentioned the novelty of monitoring vital sign trends of patients on wards. The theme 'Management of alarms' linked to Opportunity. Nurses perceived the (false) alarms generated by the system as excessive resulting in feelings of irritation and uncertainty. The theme 'Integration and compatibility with clinical workflow' linked to Opportunity. CVSM was experienced as helpful and easy to use, although integration in mobile devices and the EMR was highly favoured and the management of clinical workflows would need improvement. The theme 'Added value for nursing care' linked to Motivation. All nurses recognized the potential added value of CVSM for postoperative care. CONCLUSION: Our findings suggest all parts of the COM-B model should be considered when implementing CVSM on general wards. When the themes in Capability and Opportunity are not properly addressed by selecting interventions and policy categories, this may negatively influence the Motivation and may compromise successful implementation.

Postoperative urinary retention: risk factors, bladder filling rate and time to catheterization: an observational study as part of a randomized controlled trial.

BACKGROUND: Knowledge of risk factors for postoperative urinary retention may guide appropriate and timely urinary catheterization. We aimed to determine independent risk factors for postoperative urinary catheterization in general surgical patients. In addition, we calculated bladder filling rate and assessed the time to spontaneous voiding or catheterization. We used the patients previously determined individual maximum bladder capacity as threshold for urinary catheterization. METHODS: Risk factors for urinary catheterization were prospectively determined in 936 general surgical patients. Patients were at least 18 years of age and operated under general or spinal anesthesia without the need for an indwelling urinary catheter. Patients measured their maximum bladder capacity preoperatively at home, by voiding in a calibrated bowl after a strong urge that could no longer be ignored. Postoperatively, bladder volumes were assessed hourly with ultrasound. When patients reached their maximum bladder capacity and were unable to void, they were catheterized by the nursing staff. Bladder filling rate and time to catheterization were determined. RESULTS: Spinal anesthesia was the main independent modifiable risk factor for urinary catheterization (hyperbaric bupivacaine, relative risk 8.1, articaine RR 3.1). Unmodifiable risk factors were a maximum bladder capacity < 500 mL (RR 6.7), duration of surgery ≥ 60 min (RR 5.5), first scanned bladder volume at the Post Anesthesia Care Unit ≥250mL (RR 2.1), and age ≥ 60 years (RR 2.0). Urine production varied from 100 to 200 mL/h. Catheterization or spontaneous voiding took place approximately 4 h postoperatively. CONCLUSION: Spinal anesthesia, longer surgery time, and older age are the main risk factors for urinary retention catheterization. Awareness of these risk factors, regularly bladder volume scanning (at least every 3 h) and using the individual maximum bladder capacity as volume threshold for urinary catheterization may avoid unnecessary urinary catheterization and will prevent bladder overdistention with the attendant risk of lower urinary tract injury. TRIAL REGISTRATION: Dutch Central Committee for Human Studies registered trial database: NL 21058.099.07. Current Controlled Trials database: Preventing Bladder Catheterization after an Operation under General or Spinal Anesthesia by Using the Patient's Own Maximum Bladder Capacity as a Limit for Maximum Bladder Volume. ISRCTN97786497 . Registered 18 July 2011 -Retrospectively registered. The original study started 19 May 2008, and ended 30 April 2009, when the last patient was included.

Paravertebral catheter versus EPidural analgesia in Minimally invasive Esophageal resectioN: a randomized controlled multicenter trial (PEPMEN trial).

BACKGROUND: Thoracic epidural analgesia is the standard postoperative pain management strategy in esophageal cancer surgery. However, paravertebral block analgesia may achieve comparable pain control while inducing less side effects, which may be beneficial for postoperative recovery. This study primarily aims to compare the postoperative quality of recovery between paravertebral catheter versus thoracic epidural analgesia in patients undergoing minimally invasive esophagectomy. METHODS: This study represents a randomized controlled superiority trial. A total of 192 patients will be randomized in 4 Dutch high-volume centers for esophageal cancer surgery. Patients are eligible for inclusion if they are at least 18 years old, able to provide written informed consent and complete questionnaires in Dutch, scheduled to undergo minimally invasive esophagectomy with two-field lymphadenectomy and an intrathoracic anastomosis, and have no contra-indications to either epidural or paravertebral analgesia. The primary outcome is the quality of postoperative recovery, as measured by the Quality of Recovery-40 (QoR-40) questionnaire on the morning of postoperative day 3. Secondary outcomes include the QoR-40 questionnaire score Area Under the Curve on postoperative days 1-3, the integrated pain and systemic opioid score and patient satisfaction and pain experience according to the International Pain Outcomes (IPO) questionnaire, and cost-effectiveness. Furthermore, the groups will be compared regarding the need for additional rescue medication on postoperative days 0-3, technical failure of the pain treatment, duration of anesthesia, duration of surgery, total postoperative fluid administration day 0-3, postoperative vasopressor and inotrope use, length of urinary catheter use, length of hospital stay, postoperative complications, chronic pain at six months after surgery, and other adverse effects. DISCUSSION: In this study, it is hypothesized that paravertebral analgesia achieves comparable pain control while causing less side-effects such as hypotension when compared to epidural analgesia, leading to shorter postoperative length of stay on a monitored ward and superior quality of recovery. If this hypothesis is confirmed, the results of this study can be used to update the relevant guidelines on postoperative pain management for patients undergoing minimally invasive esophagectomy. TRIAL REGISTRATION: Netherlands Trial Registry, NL8037. Registered 19 September 2019.

Haematoma and abscess after neuraxial anaesthesia: a review of 647 cases.

Although rare, spinal haematoma and abscess after central neuraxial blocks may cause severe permanent neurological injury. Optimal treatment and outcome remain unclear. In order to identify possible predisposing patient characteristics and describe the ensuing clinical course, we searched Medline, Embase, and the Cochrane Library for reports of spinal haematomas and abscesses associated with central neuraxial blocks. Extracted data included patient characteristics, symptoms, treatment, and outcome. We analysed 409 reports, including 647 patients (387 patients with spinal haematoma and 260 patients with spinal abscess). Spinal haematoma and abscess occurred predominantly after epidural anaesthesia (58% and 83%, respectively). Neurological recovery was correlated with the severity of initial neurological deficit. When decompression of spinal haematoma was delayed for >12 h after clinical diagnosis, neurological outcome was worse compared with earlier decompression (odds ratio 4.5, 95% confidence interval 2.1-9.9, P<0.001, n=163). After spinal haematoma, 47% of published patients had full recovery, 28% had partial recovery, and in 25% no recovery was observed. Good outcome after conservative management was observed in patients with mild symptoms or with spontaneous recovery during the diagnostic and therapeutic workup. After spinal abscess, 68% of reported patients recovered fully, 21% showed partial recovery, and no recovery was reported in 11%. Persistent neurological symptoms after spinal haematoma and abscess are common and correlate with the severity of initial neurological deficit. Neurological outcome seems worse when decompressive surgery of haematoma is delayed. Notwithstanding the considerable risk of selection bias and publication bias, conservative management may be feasible in patients with mild symptoms or spontaneous recovery.

Variations in assessment and certification in postgraduate anaesthesia training: a European survey.

BACKGROUND: Postgraduate specialty training has traditionally been based on a time- and rotation-based model, but competency-based models are emerging. Because anaesthesia training evolves differently across Europe, variations in assessment and certification processes are expected, but the extent of similarities and differences is unknown. The aim of this study was to compare anaesthesia training programmes in Europe, focusing on assessment and certification processes. METHODS: We performed an online survey among national representatives of the Union of European Medical Specialists/European Board of Anaesthesiology. RESULTS: All 36 countries participated. Duration of training had a median of 5 yr (range 2.75-7). Mean number of different assessment tools was 7.45 (range 4-13), with more tools being used in competency-based programmes [mean 9.1 (sd 2.97) vs 7.0 (sd 1.97); P=0.03]. Most countries had a nationally uniform certification process. Based on a qualitative analysis of the survey findings, a categorization of countries emerged, reflecting the approach to assessment and certification. We observed two main streams of countries with an underlying knowledge or procedural focus within a time- and rotation-based apprenticeship model. These main streams are evolving, to different extents, towards a third orientation, competency-based training. CONCLUSIONS: Assessment and certification processes in European anaesthesia training are diverse. In many countries, a time-based apprenticeship model is evolving towards a competency-based certification process. This diversity precludes comparison of competence of graduating anaesthetists across Europe.

Association between delirium and cognitive change after cardiac surgery.

BACKGROUND: Previous studies provide inconsistent data on whether postoperative delirium (POD) is a risk factor for postoperative cognitive decline (POCD). We thus investigated the relationship between POD and cognitive change after cardiac surgery and assessed the relationship between preoperative cognitive domain scores and POD. METHODS: Postoperative delirium was assessed with the Confusion Assessment Method (CAM) adapted for the intensive care unit and the conventional CAM accompanied by chart review. Cognitive function was assessed with a neuropsychological test battery before elective cardiac surgery and 1 month and 1 yr afterwards. Cognitive change was calculated using the Reliable Change Index (RCI). Multiple linear regression was used to adjust for confounding. RESULTS: Of the 184 patients who completed baseline assessment, 23 (12.5%) developed POD. At 1 month, the decline in cognitive performance was worse in patients with POD [median composite RCI -1.00, interquartile range (IQR) -1.67 to 0.28] than in patients without POD (RCI -0.04, IQR -0.70 to 0.63, P =0.02). At 1 yr, both groups showed cognitive improvement on average compared with baseline (POD patients median composite RCI 0.25, IQR -0.42 to 1.31, vs non-POD patients RCI 0.92, IQR 0.18-1.53; P =0.08). Correction for differences in age and level of education did not change the results. Patients with POD performed less well than patients without POD on the preoperative Trailmaking test part A ( P =0.03). CONCLUSIONS: Postoperative delirium is independently associated with cognitive decline 1 month after surgery, but cognitive performance generally recovers in 1 yr. Patients with a predisposition to POD can be identified before surgery by worse performance in an attention task. CLINICAL TRIAL REGISTRATION: NCT00293592.

Long-term outcomes and cost effectiveness of high-dose dexamethasone for cardiac surgery: a randomised trial.

Prophylactic intra-operative administration of dexamethasone may improve short-term clinical outcomes in cardiac surgical patients. The purpose of this study was to evaluate long-term clinical outcomes and cost effectiveness of dexamethasone versus placebo. Patients included in the multicentre, randomised, double-blind, placebo-controlled DExamethasone for Cardiac Surgery (DECS) trial were followed up for 12 months after their cardiac surgical procedure. In the DECS trial, patients received a single intra-operative dose of dexamethasone 1 mg.kg-1 (n = 2239) or placebo (n = 2255). The effects on the incidence of major postoperative events were evaluated. Also, overall costs for the 12-month postoperative period, and cost effectiveness, were compared between groups. Of 4494 randomised patients, 4457 patients (99%) were followed up until 12 months after surgery. There was no difference in the incidence of major postoperative events, the relative risk (95%CI) being 0.86 (0.72-1.03); p = 0.1. Treatment with dexamethasone reduced costs per patient by £921 [€1084] (95%CI £-1672 to -137; p = 0.02), mainly through reduction of postoperative respiratory failure and duration of postoperative hospital stay. The probability of dexamethasone being cost effective compared with placebo was 97% at a threshold value of £17,000 [€20,000] per quality-adjusted life year. We conclude that intra-operative high-dose dexamethasone did not have an effect on major adverse events at 12 months after cardiac surgery, but was associated with a reduction in costs. Routine dexamethasone administration is expected to be cost effective at commonly accepted threshold levels for cost effectiveness.

Wireless non-invasive continuous respiratory monitoring with FMCW radar: a clinical validation study.

Altered respiratory rate is one of the first symptoms of medical conditions that require timely intervention, e.g., sepsis or opioid-induced respiratory depression. To facilitate continuous respiratory rate monitoring on general hospital wards a contactless, non-invasive, prototype monitor was developed using frequency modulated continuous wave radar. We aimed to study whether radar can reliably measure respiratory rate in postoperative patients. In a diagnostic cross-sectional study patients were monitored with the radar and the reference monitor (pneumotachograph during mechanical ventilation and capnography during spontaneous breathing). Eight patients were included; yielding 796 min of observation time during mechanical ventilation and 521 min during spontaneous breathing. After elimination of movement artifacts the bias and 95 % limits of agreement for mechanical ventilation and spontaneous breathing were -0.12 (-1.76 to 1.51) and -0.59 (-5.82 to 4.63) breaths per minute respectively. The radar was able to accurately measure respiratory rate in mechanically ventilated patients, but the accuracy decreased during spontaneous breathing.

Impact of adding therapeutic recommendations to risk assessments from a prediction model for postoperative nausea and vomiting.

BACKGROUND: In a large cluster-randomized trial on the impact of a prediction model, presenting the calculated risk of postoperative nausea and vomiting (PONV) on-screen (assistive approach) increased the administration of risk-dependent PONV prophylaxis by anaesthetists. This change in therapeutic decision-making did not improve the patient outcome; that is, the incidence of PONV. The present study aimed to quantify the effects of adding a specific therapeutic recommendation to the predicted risk (directive approach) on PONV prophylaxis decision-making and the incidence of PONV. METHODS: A prospective before-after study was conducted in 1483 elective surgical inpatients. The before-period included care-as-usual and the after-period included the directive risk-based (intervention) strategy. Risk-dependent effects on the administered number of prophylactic antiemetics and incidence of PONV were analysed by mixed-effects regression analysis. RESULTS: During the intervention period anaesthetists administered 0.5 [95% confidence intervals (CIs): 0.4-0.6] more antiemetics for patients identified as being at greater risk of PONV. This directive approach led to a reduction in PONV [odds ratio (OR): 0.60, 95% CI: 0.43-0.83], with an even greater reduction in PONV in high-risk patients (OR: 0.45, 95% CI: 0.28-0.72). CONCLUSIONS: Anaesthetists administered more prophylactic antiemetics when a directive approach was used for risk-tailored intervention compared with care-as-usual. In contrast to the previously studied assistive approach, the increase in PONV prophylaxis now resulted in a lower PONV incidence, particularly in high-risk patients. When one aims for a truly 'PONV-free hospital', a more liberal use of prophylactic antiemetics must be accepted and lower-risk thresholds should be set for the actionable recommendations.

Quality of pain treatment after caesarean section: Results of a multicentre cohort study.

BACKGROUND: A large cohort study recently reported high pain scores after caesarean section (CS). The aim of this study was to analyse how pain after CS interferes with patients' activities and to identify possible causes of insufficient pain treatment. METHODS: We analysed pain scores, pain-related interferences (with movement, deep breathing, mood and sleep), analgesic techniques, analgesic consumption, adverse effects and the wish to have received more analgesics during the first 24 h after surgery. To better evaluate the severity of impairment by pain, the results of CS patients were compared with those of patients undergoing hysterectomy. RESULTS: CS patients (n = 811) were compared with patients undergoing abdominal, laparoscopic-assisted vaginal or vaginal hysterectomy (n = 2406, from 54 hospitals). Pain intensity, wish for more analgesics and most interference outcomes were significantly worse after CS compared with hysterectomies. CS patients with spinal or general anaesthesia and without patient-controlled analgesia (PCA) received significantly less opioids on the ward (62% without any opioid) compared with patients with PCA (p < 0.001). Patients with PCA reported pain-related interference with movement and deep breathing between 49% and 52% compared with patients without PCA (between 68% and 73%; p-values between 0.004 and 0.013; not statistically significant after correction for multiple testing). CONCLUSION: In daily clinical practice, pain after CS is much higher than previously thought. Pain management was insufficient compared with patients undergoing hysterectomy. Unfavourable outcome was mainly associated with low opioid administration after CS. Contradictory pain treatment guidelines for patients undergoing CS and for breastfeeding mothers might contribute to reluctance of opioid administration in CS patients.

Is "really conscious" sedation with solely an opioid an alternative to every day used sedation regimes for colonoscopies in a teaching hospital? Midazolam/fentanyl, propofol/alfentanil, or alfentanil only for colonoscopy: a randomized trial.

BACKGROUND: We investigated the satisfaction of patients and endoscopists and concurrently safety aspects of an "alfentanil only" and two clinically routinely used sedation regimes in patients undergoing colonoscopy in a teaching hospital. METHODS: One hundred and eighty patients were prospectively randomized in three groups: M (midazolam/fentanyl), A (alfentanil), and P (propofol/alfentanil); M and A were administered by an endoscopy nurse, P by an anesthesia nurse. Interventions, heart rate, saturation, electrocardiogram, noninvasive blood pressure, and expiratory CO2 were monitored using video assistance. After endoscopy, patients and gastroenterologists completed questionnaires about satisfaction. RESULTS: A high level of satisfaction was found in all groups, with patients in group P being more satisfied with their sedation experience (median 1.75, p < 0.001). Gastroenterologist satisfaction varied not significantly between the three alternatives. Patients in group A felt less drowsy, could communicate more rapidly than patients in both other groups, and met discharge criteria immediately after the end of the procedure. Respiratory events associated with sedation were observed in 43% patients in group M, 47% in group P, but only 13% in group A (p < 0.001). CONCLUSIONS: These results suggest that alfentanil could be an alternative for sedation in colonoscopy even in the setting of a teaching hospital. It results in satisfied patients easily taking up information, and recovering rapidly. Although one might expect to observe more respiratory depression with an "opioid only" sedation technique without involvement of anesthesia partners, respiratory events were less frequent than when other methods were used.

Infantile postoperative encephalopathy: perioperative factors as a cause for concern.

We report on 6 infants who underwent elective surgery and developed postoperative encephalopathy, which had features most consistent with intraoperative cerebral hypoperfusion. All infants were <48 weeks' postmenstrual age and underwent procedures lasting 120 to 185 minutes. Intraoperative records revealed that most of the measured systolic blood pressure (SBP) values were <60 mm Hg (the threshold for hypotension in awake infants according to the Pediatric Advanced Life Support guidelines) but that only 11% of the measured SBP values were <1 SD of the mean definition of hypotension (<45 mm Hg) as reported in a survey of members of the Society for Pediatric Anesthesia in 2009. Four infants also exhibited prolonged periods of mild hypocapnia (<35 mm Hg). One infant did not receive intraoperative dextrose. All infants developed new-onset seizures within 25 hours of administration of the anesthetic, with a predominant cerebral pathology of supratentorial watershed infarction in the border zone between the anterior, middle, and posterior cerebral arteries. Follow-up of these infants found that 1 died, 1 had profound developmental delays, 1 had minor motor delays, 2 were normal, and 1 was lost to follow-up. Although the precise cause of encephalopathy cannot be determined, it is important to consider the role that SBP hypotension (as well as hypoglycemia, hyperthermia, hyperoxia, and hypocapnia) plays during general anesthesia in young infants in the development of infantile postoperative encephalopathy. Our observations highlight the lack of evidence-based recommendations for the lower limits of adequate SBP and end-tidal carbon dioxide in anesthetized infants.

The Dutch hospital standardised mortality ratio (HSMR) method and cardiac surgery: benchmarking in a national cohort using hospital administration data versus a clinical database.

OBJECTIVE: To compare the accuracy of data from hospital administration databases and a national clinical cardiac surgery database and to compare the performance of the Dutch hospital standardised mortality ratio (HSMR) method and the logistic European System for Cardiac Operative Risk Evaluation, for the purpose of benchmarking of mortality across hospitals. METHODS: Information on all patients undergoing cardiac surgery between 1 January 2007 and 31 December 2010 in 10 centres was extracted from The Netherlands Association for Cardio-Thoracic Surgery database and the Hospital Discharge Registry. The number of cardiac surgery interventions was compared between both databases. The European System for Cardiac Operative Risk Evaluation and hospital standardised mortality ratio models were updated in the study population and compared using the C-statistic, calibration plots and the Brier-score. RESULTS: The number of cardiac surgery interventions performed could not be assessed using the administrative database as the intervention code was incorrect in 1.4-26.3%, depending on the type of intervention. In 7.3% no intervention code was registered. The updated administrative model was inferior to the updated clinical model with respect to discrimination (c-statistic of 0.77 vs 0.85, p<0.001) and calibration (Brier Score of 2.8% vs 2.6%, p<0.001, maximum score 3.0%). Two average performing hospitals according to the clinical model became outliers when benchmarking was performed using the administrative model. CONCLUSIONS: In cardiac surgery, administrative data are less suitable than clinical data for the purpose of benchmarking. The use of either administrative or clinical risk-adjustment models can affect the outlier status of hospitals. Risk-adjustment models including procedure-specific clinical risk factors are recommended.

Including post-discharge mortality in calculation of hospital standardised mortality ratios: retrospective analysis of hospital episode statistics.

OBJECTIVES: To assess the consequences of applying different mortality timeframes on standardised mortality ratios of individual hospitals and, secondarily, to evaluate the association between in-hospital standardised mortality ratios and early post-discharge mortality rate, length of hospital stay, and transfer rate. DESIGN: Retrospective analysis of routinely collected hospital data to compare observed deaths in 50 diagnostic categories with deaths predicted by a case mix adjustment method. SETTING: 60 Dutch hospitals. PARTICIPANTS: 1 228 815 patients discharged in the period 2008 to 2010. MAIN OUTCOME MEASURES: In-hospital standardised mortality ratio, 30 days post-admission standardised mortality ratio, and 30 days post-discharge standardised mortality ratio. RESULTS: Compared with the in-hospital standardised mortality ratio, 33% of the hospitals were categorised differently with the 30 days post-admission standardised mortality ratio and 22% were categorised differently with the 30 days post-discharge standardised mortality ratio. A positive association was found between in-hospital standardised mortality ratio and length of hospital stay (Pearson correlation coefficient 0.33; P=0.01), and an inverse association was found between in-hospital standardised mortality ratio and early post-discharge mortality (Pearson correlation coefficient -0.37; P=0.004). CONCLUSIONS: Applying different mortality timeframes resulted in differences in standardised mortality ratios and differences in judgment regarding the performance of individual hospitals. Furthermore, associations between in-hospital standardised mortality rates, length of stay, and early post-discharge mortality rates were found. Combining these findings suggests that standardised mortality ratios based on in-hospital mortality are subject to so-called "discharge bias." Hence, early post-discharge mortality should be included in the calculation of standardised mortality ratios.

Near-infrared light to aid peripheral intravenous cannulation in children: a cluster randomised clinical trial of three devices.

Intravenous cannulation can be difficult in children. Recently, new devices using near-infrared light to make blood vessels visible have become available. We aimed to evaluate the effectiveness of three such devices in facilitating peripheral intravenous cannulation in children. In this cluster randomised clinical trial, daily operating rooms at a tertiary childrens' hospital were randomised to the use of the VeinViewer®, AccuVein® AV300, VascuLuminator Vision® or to a control group. We included 1913 children between birth and 18 years scheduled for elective surgery. Suitable veins for cannulation were more easily visible with the VeinViewer (307/322 (95.3%)) and AccuVein (239/254 (94.1%)) devices than with VascuLuminator (229/257 (89.1%)) (p = 0.03). However, success at the first attempt was not significantly different among groups, ranging from 73.1% to 75.3% (p = 0.93). We conclude that although vein visibility is enhanced, near-infrared devices do not improve cannulation.

General anesthesia as a possible GABAergic modulator affects visual processing in children.

Gamma-Aminobutyric Acid (GABA) inhibitory interneurons play an important role in visual processing, as is revealed by studies administering drugs in human and monkey adults. Investigating this process in children requires different methodologies, due to ethical considerations. The current study aimed to investigate whether a new method, being general anesthesia using Sevoflurane, can be used to trace the effects of GABAergic modulation on visual brain functioning in children. To this aim, visual processing was investigated in children aged 4-12 years who were scheduled for minor urologic procedures under general anesthesia in day-care treatment. In a visual segmentation task, the difference in Event-Related Potential (ERP) response to homogeneous and textured stimuli was investigated. In addition, psychophysical performance on visual acuity and contrast sensitivity were measured. Results were compared between before and shortly after anesthesia. In two additional studies, effects at 1 day after anesthesia and possible effects of task-repetition were investigated. ERP results showed longer latency and lower amplitude of the Texture Negativity (TN) component shortly after compared to before anesthesia. No effects of anesthesia on psychophysical measurements were found. No effects at 1 day after anesthesia or of repetition were revealed either. These results show that GABAergic modulation through general anesthesia affects ERP reflections of visual segmentation in a similar way in children as benzodiazepine does in adults, but that effects are not permanent. This demonstrates that ERP measurement after anesthesia is a successful method to study effects of GABAergic modulation in children.

Occurrence and determinants of poor response to short-term pre-operative erythropoietin treatment.

BACKGROUND: This study aimed to explore the occurrence and determinants of poor response to short-term pre-operative erythropoietin treatment and the effect of such poor response on transfusion in total hip arthroplasty patients. METHODS: We studied total hip arthroplasty patients who received erythropoietin before surgery. The primary outcome was the pre-operative increase in haemoglobin (delta haemoglobin) as response to erythropoietin therapy. Additionally, patients were classified in tertiles based on this delta haemoglobin: poor responders (cases), responders and good responders (controls) to erythropoietin. Patient characteristics, comedication and co-morbidity were collected as potential determinants of erythropoietin response. Regression techniques were used to estimate the strength of the associations and to assess the effect of poor response on transfusion requirement. RESULTS: A total of 379 patients receiving erythropoietin were eligible to enter the study. Mean delta haemoglobin was 19.3 g/l (standard deviation 9.4). Factors significantly associated with delta haemoglobin were the use of angiotensin II antagonists [-3.1 g/l; 95% confidence interval (CI) -5.7 to -0.6] and vitamin K antagonists (-6.9 g/l; 95% CI -10.0 to -0.2), together with body mass index (BMI) (-0.3 g/l per unit>; 95% CI -0.5 to -0.2). The additional case-control analysis yielded comparable results. Poor response to erythropoietin was associated with an increased transfusion risk (odds ratio 4.6, 95% CI 2.0-11). CONCLUSION: Use of angiotensin II receptor antagonists and vitamin K antagonists, and having a high BMI were determinants of poor response to short-term pre-operative erythropoietin treatment in total hip arthroplasty patients. Poor responders had a higher risk for perioperative blood transfusion.