A surveillance method to identify patients with sepsis from electronic health records in Hong Kong: a single centre retrospective study.

BACKGROUND: Currently there are only two population studies on sepsis incidence in Asia. The burden of sepsis in Hong Kong is unknown. We developed a sepsis surveillance method to estimate sepsis incidence from a population electronic health record (EHR) in Hong Kong using objective clinical data. The study objective was to assess our method's performance in identifying sepsis using a retrospective cohort. We compared its accuracy to administrative sepsis surveillance methods such as Angus' and Martin's methods. METHOD: In this single centre retrospective study we applied our sepsis surveillance method on adult patients admitted to a tertiary hospital in Hong Kong. Two clinicians independently reviewed the clinical notes to determine which patients had sepsis. Performance was assessed by sensitivity, specificity, positive predictive value, negative predictive value and area under the curve (AUC) of Angus', Martin's and our surveillance methods using clinical review as "gold standard." RESULTS: Between January 1 and February 28, 2018, our sepsis surveillance method identified 1352 adult patients hospitalised with suspected infection. We found that 38.9% (95%CI 36.3-41.5) of these patients had sepsis. Using a 490 patient validation cohort, two clinicians had good agreement with weighted kappa of 0.75 (95% CI 0.69-0.81) before coming to consensus on diagnosis of uncomplicated infection or sepsis for all patients. Our method had sensitivity 0.93 (95%CI 0.89-0.96), specificity 0.86 (95%CI 0.82-0.90) and an AUC 0.90 (95%CI 0.87-0.92) when validated against clinician review. In contrast, Angus' and Martin's methods had AUCs 0.56 (95%CI 0.53-0.58) and 0.56 (95%CI 0.52-0.59), respectively. CONCLUSIONS: A sepsis surveillance method based on objective data from a population EHR in Hong Kong was more accurate than administrative methods. It may be used to estimate sepsis population incidence and outcomes in Hong Kong. TRIAL REGISTRATION: This study was retrospectively registered at clinicaltrials.gov on October 3, 2019 ( NCT04114214 ).

Examination of psychological risk factors for chronic pain following cardiac surgery: protocol for a prospective observational study.

INTRODUCTION: Approximately 400 000 Americans and 36 000 Canadians undergo cardiac surgery annually, and up to 56% will develop chronic postsurgical pain (CPSP). The primary aim of this study is to explore the association of pain-related beliefs and gender-based pain expectations on the development of CPSP. Secondary goals are to: (A) explore risk factors for poor functional status and patient-level cost of illness from a societal perspective up to 12 months following cardiac surgery; and (B) determine the impact of CPSP on quality-adjusted life years (QALYs) borne by cardiac surgery, in addition to the incremental cost for one additional QALY gained, among those who develop CPSP compared with those who do not. METHODS AND ANALYSES: In this prospective cohort study, 1250 adults undergoing cardiac surgery, including coronary artery bypass grafting and open-heart procedures, will be recruited over a 3-year period. Putative risk factors for CPSP will be captured prior to surgery, at postoperative day 3 (in hospital) and day 30 (at home). Outcome data will be collected via telephone interview at 6-month and 12-month follow-up. We will employ generalised estimating equations to model the primary (CPSP) and secondary outcomes (function and cost) while adjusting for prespecified model covariates. QALYs will be estimated by converting data from the Short Form-12 (version 2) to a utility score. ETHICS AND DISSEMINATION: This protocol has been approved by the responsible bodies at each of the hospital sites, and study enrolment began May 2015. We will disseminate our results through CardiacPain.Net, a web-based knowledge dissemination platform, presentation at international conferences and publications in scientific journals. TRIAL REGISTRATION NUMBER: NCT01842568.

Effect of cultural background and healthcare environment on postoperative opioid requirement.

PURPOSE: The objective of this prospective observational study was to investigate the interactions between cultural background, healthcare environment, and postoperative pain experience. METHODS: We enrolled 128 Chinese patients living in rural mainland China and 134 patients in Hong Kong with a higher level of Western cultural influences (defined by educational attainment, place of residence, and ability to understand English). All patients had major abdominal surgery and received patient-controlled analgesia with intravenous morphine for postoperative pain relief. The primary endpoint was total opioid requirement up to 48 hr after surgery. Other measures included pain intensity, opioid-related side effects, and genetic markers for opioid responsiveness. RESULTS: The mean (95% confidence interval) cumulative opioid requirement, expressed as morphine equivalent, during the first 48 hr after surgery was significantly less in patients from mainland China (18.8 [15.7 to 22] mg) compared with patients from Hong Kong (42.0 [38.3 to 45.6] mg, P < 0.0001). In a multivariable analysis, opioid requirement was influenced by ethnicity, duration of surgery, and severity of pain upon admission to the postanesthetic care unit. CONCLUSIONS: These results suggest that postoperative pain behaviours and opioid requirement may be influenced by cultural background and healthcare environment in two populations of Chinese descent. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry (ACTRN12614000601639); registered 6 May, 2014.

RéSUMé: OBJECTIF: L'objectif de cette étude observationnelle prospective était d'étudier les interactions entre le contexte culturel, l'environnement de soins de santé et l'expérience de la douleur postopératoire. MéTHODES: Nous avons recruté 128 patients chinois vivant en zones rurales en Chine continentale et 134 patients vivant à Hong-Kong avec un haut niveau d'influences culturelles occidentales (définies par le niveau d'éducation atteint, le lieu de résidence et la capacité à comprendre l'anglais). Tous les patients avaient subi une chirurgie abdominale majeure et reçu une analgésie contrôlée par le patient par morphine intraveineuse pour le soulagement de la douleur postopératoire. Le critère d'évaluation principal était la demande totale en opioïdes pendant les 48 premières heures suivant la chirurgie. D'autres mesures ont inclus l'intensité de la douleur, les effets indésirables liés aux opioïdes et des marqueurs génétiques de sensibilité aux opioïdes. RéSULTATS: Le besoin cumulé moyen (intervalle de confiance à 95 %) cumulé en opioïdes, exprimé sous forme d'équivalent-morphine, au cours des 48 premières heures suivant la chirurgie était significativement inférieur pour les patients de Chine continentale (18,8 [15,7 à 22] mg) comparativement aux patients de Hong-Kong (42,0 [38,3 à 45,6] mg, P < 0,0001). Une analyse multifactorielle a montré que la demande en opioïdes était influencée par l'origine ethnique, la durée de l'intervention chirurgicale et l'intensité de la douleur au moment de l'arrivée dans l'unité de soins postanesthésiques. CONCLUSIONS: Ces résultats suggèrent que les comportements postopératoires envers la douleur et le besoin d'opioïdes peuvent être influencés par l'arrière-plan culturel et l'environnement des soins de santé dans deux populations différentes d'origine chinoise. ENREGISTREMENT DE L'ESSAI CLINIQUE: Registre des essais cliniques d'Australie et de Nouvelle-Zélande (ACTRN12614000601639); enregistré le 6 mai 2014.

Troponin T monitoring to detect myocardial injury after noncardiac surgery: a cost-consequence analysis.

BACKGROUND: Myocardial injury after noncardiac surgery (MINS) is a mostly asymptomatic condition that is strongly associated with 30-day mortality; however, it remains mostly undetected without systematic troponin T monitoring. We evaluated the cost and consequences of postoperative troponin T monitoring to detect MINS. METHODS: We conducted a model-based cost-consequence analysis to compare the impact of routine troponin T monitoring versus standard care (troponin T measurement triggered by ischemic symptoms) on the incidence of MINS detection. Model inputs were based on Canadian patients enrolled in the Vascular Events in Noncardiac Surgery Patients Cohort Evaluation (VISION) study, which enrolled patients aged 45 years or older undergoing inpatient noncardiac surgery. We conducted probability analyses with 10 000 iterations and extensive sensitivity analyses. RESULTS: The data were based on 6021 patients (48% men, mean age 65 [standard deviation 12] yr). The 30-day mortality rate for MINS was 9.6%. We determined the incremental cost to avoid missing a MINS event as $1632 (2015 Canadian dollars). The cost-effectiveness of troponin monitoring was higher in patient subgroups at higher risk for MINS, e.g., those aged 65 years or more, or with a history of atherosclerosis or diabetes ($1309). CONCLUSION: The costs associated with a troponin T monitoring program to detect MINS were moderate. Based on the estimated incremental cost per health gain, implementation of postoperative troponin T monitoring seems appealing, particularly in patients at high risk for MINS.

CONTEXTE: Les lésions myocardiques après chirurgie non cardiaque (CNC) sont majoritairement asymptomatiques et fortement associées au risque de mortalité dans les 30 jours; toutefois, dans la plupart des cas, elles ne sont pas détectées en l'absence d'une surveillance systématique de la troponine T. Nous avons évalué les coûts et les conséquences d'une telle surveillance pour détecter les lésions myocardiques après CNC. MÉTHODES: Nous avons mené une analyse coût-conséquence modélisée pour comparer la surveillance systématique de la troponine T aux soins habituels seuls (mesure de la troponine T seulement s'il y a présence de symptômes d'ischémie) sur la fréquence de détection de lésions myocardiques après CNC. Les données ayant servi à l'analyse provenaient des patients canadiens ayant participé à l'étude de cohorte VISION, qui visait à évaluer les complications vasculaires chez les patients de 45 ans et plus ayant subi une CNC. Nous avons mené des analyses de probabilité avec 10  000 itérations et des analyses de sensibilité approfondies. RÉSULTATS: Les données portaient sur 6021 patients (48 % du sexe masculin; âge moyen de 65 ans [écart-type de 12 ans]). Le taux de mortalité dans les 30 jours associé à une lésion myocardique après CNC était de 9,6 %. Nous avons déterminé que le coût marginal de la détection de la présence d'une lésion par surveillance de la troponine T était de 1632 $ (dollars canadiens en 2015). Le rapport coût-efficacité était plus bas pour les sous-groupes de patients à risque élevé de lésion myocardique après CNC, comme les patients de 65 ans et plus ou ceux ayant des antécédents d'athérosclérose ou de diabète (1309 $), que pour leurs pairs. CONCLUSION: Les coûts associés à un programme de surveillance de la troponine T pour détecter les lésions myocardiques après CNC étaient modérés. Le coût marginal estimé par gain de santé indique que la mise en œuvre de ce type de programme pourrait être une option intéressante, surtout pour les patients à risque élevé de lésion myocardique après CNC.

Perioperative stroke in noncardiac, nonneurosurgical surgery.

Perioperative stroke after noncardiac, nonneurosurgical procedures is more common than generally acknowledged. It is reported to have an incidence of 0.05-7% of patients. Most are thrombotic in origin and are noted after discharge from the postanesthetic care unit. Common predisposing factors include age, a previous stroke, atrial fibrillation, and vascular and metabolic diseases. The mortality is more than two times greater than in strokes occurring outside the hospital. Delayed diagnosis and a synergistic interaction between the inflammatory changes normally associated with stroke, and those normally occurring after surgery, may explain this increase. Intraoperative hypotension is an infrequent direct cause of stroke. Hypotension will augment the injury produced by embolism or other causes, and this may be especially important in the postoperative period, during which monitoring is not nearly as attentive as in the operating room. Increased awareness and management of predisposing risk factors with early detection should result in improved outcomes.

A cost-benefit analysis of the ENIGMA trial.

BACKGROUND: The ENIGMA trial was a prospective, randomized, multicenter study that evaluated the clinical consequences of including N2O in general anesthesia. Patients who were given a N2O-free anesthetic when undergoing major surgery for which the expected hospital stay was at least 3 days had lower rates of some postoperative complications. This suggests that, despite a higher consumption of potent inhalational agent, there could be a financial benefit when N2O is avoided in such settings. METHODS: A retrospective cost analysis of the 2,050 patients recruited to the ENIGMA trial was performed. We measured costs from the perspective of an implementing hospital. Direct health care costs include the costs for maintaining anesthesia, daily medications, hospitalization, and complications. The primary outcome was the net financial savings from avoiding N2O in major noncardiac surgery. Comparisons between groups were analyzed using Student t test and bootstrap methods. Sensitivity analyses were also performed. RESULTS: Rates of some serious complications were higher in the N2O group. Total costs in the N2O group were $16,203 and in the N2O-free group $13,837, mean difference of $2,366 (95% CI: 841-3,891); P = 0.002. All sensitivity analyses retained a significant difference in favor of the N2O-free group (all P ≤ 0.005). CONCLUSIONS: Despite N2O reducing the consumption of more expensive potent inhalational agent, there were marked additional costs associated with its use in adult patients undergoing major surgery because of an increased rate of complications. There is no cogent argument to continue using N2O on the basis that it is an inexpensive drug.

The effect of bispectral index monitoring on long-term survival in the B-aware trial.

BACKGROUND: When anesthesia is titrated using bispectral index (BIS) monitoring, patients generally receive lower doses of hypnotic drugs. Intraoperative hypotension and organ toxicity might be avoided if lower doses of anesthetics are administered, but whether this translates into a reduction in serious morbidity or mortality remains controversial. The B-Aware Trial randomly allocated 2463 patients at high risk of awareness to BIS-guided anesthesia or routine care. We tested the hypothesis that the risks of death, myocardial infarction (MI), and stroke would be lower in patients allocated to BIS-guided management than in those allocated to routine care. METHODS: The medical records of all patients who had not died within 30 days of surgery were reviewed. The date and cause of death and occurrence of MI or stroke were recorded. A telephone interview was then conducted with all surviving patients. The primary end point of the study was survival. RESULTS: The median follow-up time was 4.1 (range: 0-6.5) years. Five hundred forty-eight patients (22.2%) had died since the index surgery, 220 patients (8.9%) had an MI, and 115 patients (4.7%) had a stroke. The risk of death in BIS patients was not significantly different than in routine care patients (hazard ratio = 0.86 [95% confidence interval {CI}: 0.72-1.01]; P = 0.07). However, propensity score analysis indicated that the hazard ratio for death in patients who recorded BIS values <40 for >5 min compared with other BIS-monitored patients was 1.41 (95% CI: 1.02-1.95; P = 0.039). In addition, the odds ratios for MI in patients who recorded BIS values <40 for >5 min compared with other BIS-monitored patients was 1.94 (95% CI: 1.12-3.35; P = 0.02) and the odds ratio for stroke was 3.23 (95% CI: 1.29-8.07; P = 0.01). CONCLUSIONS: Monitoring with BIS and absence of BIS values <40 for >5 min were associated with improved survival and reduced morbidity in patients enrolled in the B-Aware Trial.