Numerous risk prediction models are available for predicting delirium after cardiac surgery, but few have been directly compared with one another or been validated in an independent data set. We conducted a systematic review to identify validated risk prediction models of delirium (using the Confusion Assessment Method-Intensive Care Unit tool) after cardiac surgery and assessed the transportability of the risk prediction models on a prospective cohort of 600 consecutive patients undergoing cardiac surgery at a university hospital in Hong Kong from July 2013 to July 2015. The discrimination (c-statistic), calibration (GiViTI calibration belt), and clinical usefulness (decision curve analysis) of the risk prediction models were examined in a stepwise manner. Three published high-quality intensive care unit delirium risk prediction models (n=5939) were identified: Katznelson, the original PRE-DELIRIC, and the international recalibrated PRE-DELIRIC model. Delirium occurred in 83 patients (13.8%, 95% CI: 11.2-16.9%). After updating the intercept and regression coefficients in the Katznelson model, there was fair discrimination (0.62, 95% CI: 0.58-0.66) and good calibration. As the original PRE-DELIRIC model was already validated externally and recalibrated in six countries, we performed a logistic calibration on the recalibrated model and found acceptable discrimination (0.75, 95% CI: 0.72-0.79) and good calibration. Decision curve analysis demonstrated that the recalibrated PRE-DELIRIC risk model was marginally more clinically useful than the Katznelson model. Current models predict delirium risk in the intensive care unit after cardiac surgery with only fair to moderate accuracy and are insufficient for routine clinical use.

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IntroductionPatients and their families are understandably anxious about the risk of complications and unfamiliar experiences following cardiac surgery. Providing information about postoperative care in the intensive care unit (ICU) to patients and families may lead to lower anxiety levels, and increased satisfaction with healthcare. The objectives of this study are to evaluate the effectiveness of preoperative patient education provided for patients undergoing elective cardiac surgery.Methods and analysis100 patients undergoing elective coronary artery bypass graft, with or without valve replacement surgery, will be recruited into a 2-group, parallel, superiority, double-blinded randomised controlled trial. Participants will be randomised to either preoperative patient education comprising of a video and ICU tour with standard care (intervention) or standard education (control). The primary outcome measures are the satisfaction levels of patients and family members with ICU care and decision-making in the ICU. The secondary outcome measures are patient anxiety and depression levels before and after surgery.Ethics and disseminationEthical approval has been obtained from the Joint Chinese University of Hong Kong—New Territories East Cluster Clinical Research Ethics Committee (reference number CREC 2015.308). The findings will be presented at conferences and published in peer-reviewed journals. Study participants will receive a 1-page plain language summary of results.Trial registration numberChiCTR-IOR-15006971.

BackgroundOutpatient anesthesia clinics are well established in North America, Europe and Australia, but few economic evaluations have been published. The Perioperative Systems in Hong Kong are best described as a hybrid model of the new and old systems of surgical care. In this matched cohort study, we compared the costs and effects of an outpatient anesthesia clinic (OPAC) with the conventional system of admitting patients to the ward a day before surgery for their pre-anesthesia consultation. A second objective of the study was to determine the patient’s median Willingness To Pay (WTP) value for an OPAC.MethodsA total of 352 patients were matched (1:1) on their elective surgical procedure to either the clinic group or to the conventional group. The primary outcome was quality of recovery score and overall perioperative treatment cost (US$). To detect a difference in the joint cost-effect relationship between groups, a cost-effectiveness acceptability curve (CEAC) was drawn. A modified Poisson regression model was used to examine the factors associated with patients willing to pay more than the median WTP value for an OPAC.ResultsThe quality of recovery scores on the first day after surgery between the clinic and conventional groups were similar (mean difference, -0.1; 95% confidence interval (CI), -0.6 to 0.3; P = 0.57). Although the preoperative costs were less in the clinic group (mean difference, -$463, 95% CI, -$648 to -$278 per patient; P <0.001), the total perioperative cost was similar between groups (mean difference, -$172; 95% CI, -$684 to $340 per patient; P = 0.51). The CEAC showed that we could not be 95% confident that the clinic was cost-effective. Compared to the conventional group, clinic patients were three times more likely to prefer OPAC care (relative risk (RR) 2.75, 95% CI, 2.13 to 3.55; P <0.001) and pay more than the median WTP (US$13) for a clinic consultation (RR 3.27, 95% CI, 2.32 to 4.64; P <0.001).ConclusionsThere is uncertainty about the cost-effectiveness of an OPAC in the Hong Kong setting. Most clinic patients were willing to pay a small amount for an anesthesia clinic consultation.

In extending the role of the acute pain service to a specific group of major surgical procedures, the acute pain service was likely to be cost effective.

Vitamin D may have an important role in pain perception. Inadequate vitamin D levels are associated with suboptimal recovery after surgery. However, the effects of hypovitaminosis D on postoperative pain-related outcomes and its impact on health-related quality of life after surgery are not well understood. The objective of this study was to determine the effects of hypovitaminosis D on postoperative pain-related outcomes and health-related quality of life at 3 months after knee arthroplasty.This was a longitudinal cohort study of 191 consecutive Hong Kong Chinese patients who were given patient-controlled morphine analgesia for up to 72 hours after 214 knee arthroplasties. Serum total 25-hydroxyvitamin D (25-OHD) concentration was assessed by liquid chromatography-tandem mass spectrometry. The primary outcomes were postoperative pain intensity at rest scores (0–72 h), Western Ontario and McMaster Universities (WOMAC) osteoarthritis index (pain, stiffness and function), and moderate-to-severe persistent pain (transformed WOMAC pain score of 0–75 at 3 months after knee arthroplasty; 0, extreme pain; 100, no pain). Group differences were analyzed using generalized estimating equation models and a logistic regression model.The prevalence of preoperative hypovitaminosis D (25-OHD <50 nmol/L) was 44% (95% confidence interval [CI]: 37%–51%). There were transient higher pain intensity scores in the moderate-to-severe hypovitaminosis D (25-OHD <30 nmol/L) group compared with the sufficient vitamin D group. Vitamin D status had no effect on total WOMAC index (P = 0.22). The incidence of moderate-to-severe persistent pain was 9% (95% CI: 6%–14%). Hypovitaminosis D increased the risk of moderate-to-severe persistent pain (adjusted odds ratio 2.64, 95% CI: 1.03–6.77).Preoperative hypovitaminosis D had subtle effects on pain intensity scores in the early postoperative period and is a risk factor for moderate-to-severe persistent pain after knee arthroplasty. Hypovitaminosis D was not associated with worse health-related quality of life at 3 months after knee arthroplasty.

ObjectiveThis study examined the risk factors associated with failure of enhanced recovery protocol after major hepatobiliary and pancreatic (HBP) surgery.Setting and participantsA retrospective cohort of 194 adult patients undergoing major HBP surgery at a university hospital in Hong Kong was followed up for 30 days. The patients were from a larger cohort study of 736 consecutive adults with preoperative urinary cotinine concentration to examine the association between passive smoking and risk of perioperative respiratory complications and postoperative morbidities.Outcome measuresThe primary outcome was failure of enhanced recovery protocol. This was defined as a composite measure of the following events: intensive care unit (ICU) stay more than 24 h after surgery, unplanned admission to ICU within 30 days after surgery, hospital readmission, reoperation and mortality.ResultsThere were 25 failures of enhanced recovery after HBP surgery (12.9%, 95% CI 8.5% to 18.4%). After adjusting for elective ICU admission, smokers (relative risk (RR ) 2.21, 95% CI 1.10 to 4.46), high preoperative alanine transaminase/glutamic-pyruvic transaminase (RR 3.55,95% CI 1.68 to 7.49) and postoperative morbidities (RR 2.69, 95% CI 1.30 to 5.56) were associated with failures of enhanced recovery in the generalised estimating equation risk model. Compared with those managed successfully, failures stayed longer in ICU (median 19 vs 25 h, p<0.001) and in hospital for postoperative care (median 7 vs 13 days, p=0.003).ConclusionsSmokers and patients having high preoperative alanine transaminase/glutamic-pyruvic transaminase concentration or have a high risk of postoperative morbidities are likely to fail enhanced recovery protocol in HBP surgery programmes.

One in 5 adults was exposed to environmental tobacco smoke before surgery. Passive cigarette smoking showed very little, if any, increased risk of perioperative respiratory complications. Both active exposure and passive exposure to cigarette smoke increased the risk of postoperative morbidity.