Purpose Malignant hyperthermia (MH) is an autosomal dominant pharmacogenetic disorder that is manifested on exposure of susceptible individuals to halogenated anesthetics or succinylcholine. Since MH is associated primarily with mutations in the ryanodine receptor type 1 (RYR1) gene, the purpose of this study was to determine the distribution and frequency of MH causative RyR1 mutations in the Canadian MH susceptible (MHS) population. Methods In this study, we screened a representative cohort of 36 unrelated Canadian MHS individuals for RYR1 mutations by sequencing complete RYR1 transcripts and selected regions of CACNA1S transcripts. We then analyzed the correlation between caffeine-halothane contracture test (CHCT) results and RYR1 genotypes within MH families. Results Eighty-six percent of patients had at least one RyR1 mutation (31 out of 36), five of which were unrelated individuals who were double-variant carriers. Fifteen of the 27 mutations identified in RYR1 were novel. Eight novel mutations, involving highly conserved amino acid residues, were predicted to be causal. Two of the mutations co-segregated with the MHS phenotype within two large independent families (a total of 79 individuals). Fourteen percent of MHS individuals (five out of 36) carried neither RYR1 nor known CACNA1S mutations. Conclusions The distribution and frequency of MH causative RyR1 mutations in the Canadian MHS population are close to those of European MHS populations. Novel mutations described in this study will contribute to the worldwide pool of MH-associated mutations in the RYR1 gene, ultimately increasing the value of MH genetic diagnostic testing. RésuméObjectif L'hyperthermie maligne (HM) est une maladie pharmacoge´ne´tique he´re´ditaire dominante autosomique qui se manifeste lors de l'exposition des personnes susceptibles a`des anesthe´siques haloge´ne´s ou à la succinylcholine. E´tant donne´que l'HM est principalement associe´e aux mutations au niveau du ge`ne des re´cepteurs de ryanodine de type 1 (RYR1), l'objectif de cette e´tude e´tait de de´terminer la distribution et la fre´quence des mutations RyR1 causant une HM chez la population canadienne susceptible a`l'HM (SHM). Méthode Dans cette e´tude, nous avons examine´une cohorte repre´sentative de 36 personnes canadiennes SHM This article is accompanied by an editorial. Please see Can J Anesth 2011; 58: 6.

Background A retrospective cohort study was conducted in patients undergoing postoperative home monitoring (POHM) following elective primary hip or knee replacements. Objective The objectives of our study were to compare the cost per patient, readmissions rate, emergency room visits, and mortality within 30 days to the historical standard of care using descriptive analysis. Methods After Research Ethics Board approval, patients who were enrolled and had completed a POHM study were individually matched to historical controls by age, American Society of Anesthesiology class, and procedure at a ratio 1:2. Results A total of 54 patients in the study group and 107 in the control group were eligible for the analysis. Compared with the historical standard of care, the average cost per case was Can $5826.32 (SD 1418.89) in the POHM group and Can $9198.58 (SD 1513.59) for controls. After 30 days, there were 2 emergency room visits (3.7%) and 0 readmissions in the POHM group, whereas there were 8 emergency room visits (7.5%) and 2 readmissions (1.9%) in the control group. No mortalities occurred in either group. Conclusions The POHM study offers an early hospital discharge pathway for elective hip and knee procedures at a 38% reduction of the standard of care cost. The multidisciplinary transitional POHM team may provide a reliable forum to minimize readmissions, and emergency room visits within 30 days postoperatively. Trial Registration ClinicalTrials.gov NCT02143232; https://clinicaltrials.gov/ct2/show/NCT02143232 (Archived by WebCite at http://www.webcitation.org/73WQ9QR6P)

Background We conducted a prospective observational study of patients undergoing elective primary hip or knee replacements to examine the feasibility of a postoperative home monitoring system as transitional care to support patients following their surgery in real time. Objective The primary outcome was the mean percentage of successful wireless transmissions from home of blood pressure levels, heart rate, oxygen saturation levels, and pain scores until postoperative day 4 with a feasibility target of ≥90%. Methods Patients with an expected length of stay ≤1 day, age 18-80 years, Revised Cardiac Risk Index ≤ class 2, and caretakers willing to assist at home were eligible. Patient satisfaction, as a secondary outcome, was also evaluated. Wireless monitoring equipment (remote patient monitoring, Telus Canada) was obtained and a multidisciplinary care team was formed. Results We conducted the study after obtaining Research Ethics Board approval; 54 patients completed the study: 21 males, 33 females. In total, we evaluated 9 hips, 4 hip resurfacing, 26 total knees, and 15 hemi-knees. The mean transmission rate was 96.4% (SD 5.9%; 95% CI 94.8-98.0). The median response to “I would recommend the Remote Monitoring System program to future patients” was 4.5 (interquartile range 4-5), with 1 being “strongly disagree” and 5 “strongly agree.” At 30 days postop, there was no mortality or readmission. Conclusions This is an evolving new paradigm for postoperative care and the first feasibility study on monitoring biometrics after primary hip or knee replacement. Postoperative home monitoring combines current technology with real-time support by a multidisciplinary transitional care team after discharge, facilitating postsurgical care with successful wireless transmission of vitals. The postoperative home monitoring implementation is, therefore, generalizable to other surgical discharges from hospitals. Trial Registration ClinicalTrials.gov NCT02143232; https://clinicaltrials.gov/ct2/show/NCT02143232 (Archived by WebCite at http://www.webcitation.org/71ugAhhIk)

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