Post-discharge after surgery Virtual Care with Remote Automated Monitoring-1 (PVC-RAM-1) technology versus standard care: randomised controlled trial.

OBJECTIVE: To determine if virtual care with remote automated monitoring (RAM) technology versus standard care increases days alive at home among adults discharged after non-elective surgery during the covid-19 pandemic. DESIGN: Multicentre randomised controlled trial. SETTING: 8 acute care hospitals in Canada. PARTICIPANTS: 905 adults (≥40 years) who resided in areas with mobile phone coverage and were to be discharged from hospital after non-elective surgery were randomised either to virtual care and RAM (n=451) or to standard care (n=454). 903 participants (99.8%) completed the 31 day follow-up. INTERVENTION: Participants in the experimental group received a tablet computer and RAM technology that measured blood pressure, heart rate, respiratory rate, oxygen saturation, temperature, and body weight. For 30 days the participants took daily biophysical measurements and photographs of their wound and interacted with nurses virtually. Participants in the standard care group received post-hospital discharge management according to the centre's usual care. Patients, healthcare providers, and data collectors were aware of patients' group allocations. Outcome adjudicators were blinded to group allocation. MAIN OUTCOME MEASURES: The primary outcome was days alive at home during 31 days of follow-up. The 12 secondary outcomes included acute hospital care, detection and correction of drug errors, and pain at 7, 15, and 30 days after randomisation. RESULTS: All 905 participants (mean age 63.1 years) were analysed in the groups to which they were randomised. Days alive at home during 31 days of follow-up were 29.7 in the virtual care group and 29.5 in the standard care group: relative risk 1.01 (95% confidence interval 0.99 to 1.02); absolute difference 0.2% (95% confidence interval -0.5% to 0.9%). 99 participants (22.0%) in the virtual care group and 124 (27.3%) in the standard care group required acute hospital care: relative risk 0.80 (0.64 to 1.01); absolute difference 5.3% (-0.3% to 10.9%). More participants in the virtual care group than standard care group had a drug error detected (134 (29.7%) v 25 (5.5%); absolute difference 24.2%, 19.5% to 28.9%) and a drug error corrected (absolute difference 24.4%, 19.9% to 28.9%). Fewer participants in the virtual care group than standard care group reported pain at 7, 15, and 30 days after randomisation: absolute differences 13.9% (7.4% to 20.4%), 11.9% (5.1% to 18.7%), and 9.6% (2.9% to 16.3%), respectively. Beneficial effects proved substantially larger in centres with a higher rate of care escalation. CONCLUSION: Virtual care with RAM shows promise in improving outcomes important to patients and to optimal health system function. TRIAL REGISTRATION: ClinicalTrials.gov NCT04344665.

Association between postsurgical pain and heart rate variability: protocol for a scoping review.

INTRODUCTION: Surgical interventions can elicit neuroendocrine responses and sympathovagal imbalance, ultimately affecting cardiac autonomic function. Cardiac complications account for 30% of postoperative complications and are the leading cause of morbidity and mortality following non-cardiac surgery. One cardiovascular parameter, heart rate variability (HRV), has been found to be predictive of postoperative morbidity and mortality. HRV is defined as variation in time intervals between heartbeats and is affected by cardiac autonomic balance. Furthermore, altered HRV has been shown to predict cardiovascular events in non-surgical settings. In multiple studies, experimentally induced pain in healthy humans leads to reduced HRV suggesting a causal relationship. In a different studies, chronic pain has been associated with altered HRV, however, in the setting of clinical pain conditions, it remains unclear how much HRV impairment is due to pain itself versus autonomic changes related to analgesia. We aim to review the available evidence describing the association between postsurgical pain and HRV alterations in the early postoperative period. METHODS AND ANALYSIS: We will conduct a scoping review of relevant studies using detailed searches of MEDLINE and EMBASE, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Included studies will involve participants undergoing non-cardiac surgery and investigate outcomes of (1) measures of pain intensity; (2) measures of HRV and (3) statistical assessment of association between #1 and #2. As secondary review outcomes included studies will also be examined for other cardiovascular events and for their attempts to control for analgesic treatment and presurgical HRV differences among treatment groups in the analysis. This work aims to synthesise available evidence to inform future research questions related to postsurgical pain and cardiac complications. ETHICS AND DISSEMINATION: Ethics review and approval is not required for this review. The results will be submitted for publication in peer-reviewed journals.

Post Discharge after Surgery Virtual Care with Remote Automated Monitoring Technology (PVC-RAM): protocol for a randomized controlled trial.

BACKGROUND: After nonelective (i.e., semiurgent, urgent and emergent) surgeries, patients discharged from hospitals are at risk of readmissions, emergency department visits or death. During the coronavirus disease 2019 (COVID-19) pandemic, we are undertaking the Post Discharge after Surgery Virtual Care with Remote Automated Monitoring Technology (PVC-RAM) trial to determine if virtual care with remote automated monitoring (RAM) compared with standard care will increase the number of days adult patients remain alive at home after being discharged following nonelective surgery. METHODS: We are conducting a randomized controlled trial in which 900 adults who are being discharged after nonelective surgery from 8 Canadian hospitals are randomly assigned to receive virtual care with RAM or standard care. Outcome adjudicators are masked to group allocations. Patients in the experimental group learn how to use the study's tablet computer and RAM technology, which will measure their vital signs. For 30 days, patients take daily biophysical measurements and complete a recovery survey. Patients interact with nurses via the cellular modem-enabled tablet, who escalate care to preassigned and available physicians if RAM measurements exceed predetermined thresholds, patients report symptoms, a medication error is identified or the nurses have concerns they cannot resolve. The primary outcome is number of days alive at home during the 30 days after randomization. INTERPRETATION: This trial will inform management of patients after discharge following surgery in the COVID-19 pandemic and offer insights for management of patients who undergo nonelective surgery in a nonpandemic setting. Knowledge dissemination will be supported through an online multimedia resource centre, policy briefs, presentations, peer-reviewed journal publications and media engagement. TRIAL REGISTRATION: ClinicalTrials.gov, no. NCT04344665.

Scoping review of the association between postsurgical pain and heart rate variability parameters.

Surgical interventions can elicit neuroendocrine and sympathovagal responses, leading to cardiac autonomic imbalance. Cardiac complications account for approximately 30% of postoperative complications. Altered heart rate variability (HRV) was initially described in the 1970s as a predictor of acute coronary syndromes and has more recently been shown to be an independent predictor of postoperative morbidity and mortality after noncardiac surgery. In general, HRV reflects autonomic balance, and altered HRV measures have been associated with anesthetic use, chronic pain conditions, and experimental pain. Despite the well-documented relationship between altered HRV and postsurgical outcomes and various pain conditions, there has not been a review of available evidence describing the association between postsurgical pain and HRV. We examined the relationship between postsurgical pain and HRV. MEDLINE and EMBASE databases were searched until December 2020 and included all studies with primary data. Two reviewers independently assessed risk of bias for each study using the criteria outlined in the Cochrane Handbook for Systematic Review of Interventions. A total of 8 studies and 1002 participants were included. Studies examined the association of postsurgical pain and HRV or analgesia nociception index derived from HRV. There was a statistically significant association between HRV measures and postsurgical pain in 6 of 8 studies. Heterogeneity of studies precluded meta-analyses. No studies reported cardiovascular outcomes. There is a potential association between postsurgical pain and HRV or analgesia nociception index, although results are likely impacted by confounding variables. Future studies are required to better delineate the relationship between postsurgical pain and HRV and impacts on cardiovascular outcomes.

Prevalence of Postoperative Pain Following Hospital Discharge: Protocol for a Systematic Review.

BACKGROUND: Pain is one of the most common, feared, and unpleasant symptoms associated with surgery. However, there is a clear gap in patient care after surgical patients are discharged from hospital, resulting in poorly controlled postoperative pain. Inadequate pain management after discharge can have detrimental effects on quality of life and lead to the development of chronic postsurgical pain. The severity of postoperative pain before discharge is well described, but less emphasis has been placed on assessing pain at home after hospital discharge. OBJECTIVE: The objective of this review is to summarize the prevalence of moderate-to-severe postoperative pain within the first 1 to 14 days after hospital discharge. METHODS: A detailed search of epidemiological studies investigating postoperative pain will be conducted on MEDLINE and EMBASE from their inception until the date the searches are run. The primary outcome will be the proportion of patients reporting moderate-to-severe postoperative pain at rest and with movement within the first 1 to 14 days after hospital discharge. The secondary outcomes will include a comparison of postoperative pain after discharge between patients who underwent ambulatory and inpatient surgery, and adverse outcomes attributable to poor pain control after hospital discharge (eg, readmission to hospital, emergency room or other unplanned medical visits, or a decrease in quality of life). RESULTS: The protocol has been registered in PROSPERO (registration number CRD42020194346). The search strategies for MEDLINE and EMBASE have been completed. The final results are expected to be published in May 2021. CONCLUSIONS: This systematic review is expected to synthesize evidence describing the prevalence of postoperative pain after hospital discharge. Available epidemiological evidence may help inform the magnitude of the problem of postoperative pain at home after hospital discharge. TRIAL REGISTRATION: PROSPERO International Prospective Register of Systematic Reviews CRD42020194346; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=194346. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/22437.

Clinical impact of disinvestment in hydroxyethyl starch for patients undergoing coronary artery bypass surgery: a retrospective observational study.

PURPOSE: To examine the effect of discontinuing hydroxyethyl starch (HES) solutions on length of hospital stay, transfusion, risk of death, acute kidney injury (AKI), and dialysis. METHODS: We conducted a historical cohort study of linked administrative and clinical databases in patients undergoing coronary artery bypass surgery (CABG) on cardiopulmonary bypass. We used propensity scores to match patients who did not receive HES (after discontinuation) with patients exposed to HES (before discontinuation) and also controlled for albumin exposure. Hospital length of stay (the primary outcome) was analyzed using Fine-Gray proportional hazard regression, with hospital discharge as the outcome and death as a competing risk. Adverse outcomes were compared between matched patients using conditional logistic regression. RESULTS: We compared 1,085 propensity score-matched pairs (n = 2,170) from a pool of 2,757 patients. Discontinuation of HES was associated with shorter length of hospital stay, as evidenced by an increased probability of discharge (hazard ratio, 1.24; 95% confidence interval [CI], 1.14 to 1.35) and a reduced risk of red blood cell transfusion (odds ratio [OR], 0.68; 95% CI, 0.55 to 0.84), plasma transfusion (OR, 0.48; 95% CI, 0.34 to 0.66), and platelet transfusion (OR, 0.62; 95% CI, 0.44 to 0.87). Discontinuation of HES was not associated with in-hospital mortality (OR, 0.74; 95% CI, 0.36 to 1.54), AKI (OR, 0.84; 95% CI, 0.57 to 1.25), or dialysis (OR, 0.83; 95% CI, 0.25 to 2.73). CONCLUSIONS: For patients undergoing CABG on cardiopulmonary bypass, discontinuation of HES was associated with reduced hospital length of stay and reduced blood product transfusion, without measurable change in renal failure, dialysis rate, or in-hospital mortality. Our results should be interpreted with caution, though we found no evidence of harms associated with discontinuing HES. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT02329158); registered 31 December, 2014.

A Case Report of the Anesthetic Management for Liver Retransplantation in a Patient With a Bronchobiliary Fistula.

A 64-year-old woman with a previous liver transplant developed graft failure with biliary complications including a bronchobiliary fistula, which did not respond to preoperative conservative therapy. Liver retransplantation provided definitive therapy for the liver failure and bronchobiliary fistula. We present anesthestic considerations for the intraoperative management of a liver retransplant with one-lung ventilation.

A multicentre randomized-controlled trial of inhaled milrinone in high-risk cardiac surgical patients.

PURPOSE: Inhaled milrinone (iMil) has been used for the treatment of pulmonary hypertension (PH) but its efficacy, safety, and prophylactic effects in facilitating separation from cardiopulmonary bypass (CPB) and preventing right ventricular (RV) dysfunction have not yet been evaluated in a clinical trial. The purpose of this study was to investigate if iMil administered before CPB would be superior to placebo in facilitating separation from CPB. METHODS: High-risk cardiac surgical patients with PH were randomized to receive iMil or placebo after the induction of anesthesia and before CPB. Hemodynamic parameters and RV function were evaluated by means of pulmonary artery catheterization and transesophageal echocardiography. The groups were compared for the primary outcome of the level of difficulty in weaning from CPB. Among the secondary outcomes examined were the reduction in the severity of PH, the incidence of RV failure, and mortality. RESULTS: Of the 124 patients randomized, the mean (standard deviation [SD]) EuroSCORE II was 8.0 (2.6), and the baseline mean (SD) systolic pulmonary artery pressure (SPAP) was 53 (9) mmHg. The use of iMil was associated with increases in cardiac output (P = 0.03) and a reduction in SPAP (P = 0.04) with no systemic hypotension. Nevertheless, there was no difference in the combined incidence of difficult or complex separation from CPB between the iMil and control groups (30% vs 28%, respectively; absolute difference, 2%; 95% confidence interval [CI], -14 to 18; P = 0.78). There was also no difference in RV failure between the iMil and control groups (15% vs 14%, respectively; difference, 1%; 95% CI, -13 to 12; P = 0.94). Mortality was increased in patients with RV failure vs those without (22% vs 2%, respectively; P < 0.001). CONCLUSION: In high-risk cardiac surgery patients with PH, the prophylactic use of iMil was associated with favourable hemodynamic effects that did not translate into improvement of clinically relevant endpoints. This trial was registered at ClinicalTrials.gov; identifier: NCT00819377.

RéSUMé: OBJECTIF: La milrinone inhalée est utilisée pour traiter l'hypertension pulmonaire (HP) mais son efficacité, son innocuité et ses effets prophylactiques pour faciliter le sevrage de la circulation extracorporelle (CEC) et prévenir la dysfonction ventriculaire droite (VD) n'ont pas encore été évalués dans le cadre d'une étude clinique. L'objectif de cette étude était d'examiner si la milrinone inhalée avant la CEC serait supérieure à un placebo pour faciliter le sevrage de la CEC. MéTHODE: Des patients de chirurgie cardiaque à risque élevé et souffrant d'HP ont été randomisés à recevoir de la milrinone inhalée ou un placebo après l'induction de l'anesthésie et avant la CEC. Les paramètres hémodynamiques et la fonction VD ont été évalués à l'aide d'un cathéter de l'artère pulmonaire et d'une échocardiographie transœsophagienne. Les groupes ont été comparés selon notre critère d'évaluation principal, soit le niveau de difficulté du sevrage de la CEC. Parmi les critères d'évaluation secondaires examinés figuraient la réduction de la gravité de l'HP, l'incidence d'insuffisance cardiaque droite et la mortalité. RéSULTATS: Au total, 124 patients ont été randomisés. Le score EuroSCORE II moyen (écart type [ÉT]) était de 8,0 (2,6), et la pression systolique de l'artère pulmonaire moyenne de base (ÉT) était de 53 (9) mmHg. L'utilisation de milrinone inhalée a été associée à des augmentations du débit cardiaque (P = 0,03) et à une réduction de la pression systolique de l'artère pulmonaire (P = 0,04) sans hypotension systémique. Toutefois, aucune différence n'a été observée dans l'incidence combinée de sevrage difficile ou complexe de la CEC entre le groupe milrinone inhalée et le groupe témoin (30 % vs 28 %, respectivement; différence absolue, 2 %; intervalle de confiance [IC] 95 %, −14 à 18; P = 0,78). Aucune différence n'a été observée non plus en matière d'insuffisance cardiaque droite entre le groupe milrinone inhalée et le groupe témoin (15 % vs 14 %, respectivement; différence, 1 %; IC 95 %, −13 à 12; P = 0,94). La mortalité était augmentée chez les patients avec insuffisance cardiaque droite (22 % vs 2 %, respectivement; P < 0.001). CONCLUSION: Chez les patients de chirurgie cardiaque à risque élevé atteints de HP, l'utilisation prophylactique de milrinone inhalée a été associée à des effets hémodynamiques favorables qui ne se sont pas traduits en améliorations des critères pertinents d'un point de vue clinique. Cette étude a été enregistrée au ClinicalTrials.gov; identifiant : NCT00819377.

A systematic review of transthoracic and transesophageal echocardiography in non-cardiac surgery: implications for point-of-care ultrasound education in the operating room.

PURPOSE: Point-of-care ultrasound (POCU) is an evolving field in anesthesia. Therefore a systematic review of common diagnoses made by POCU during non-cardiac surgery was conducted. The information obtained from the review may be used to develop POCU curricula for the perioperative setting during non-cardiac surgery. SOURCE: A systematic review was conducted for perioperative use of transthoracic /transesophageal echocardiography (TTE/TEE) in high-risk patients or in other patients experiencing periods of hemodynamic instability. The diagnoses included segmental wall motion abnormalities (SWMAs), low left ventricular ejection fraction (LVEF), hypovolemia, air embolism, cardiac/aortic thrombus, pulmonary embolus (PE), aortic valve disease, mitral valve disease, tricuspid valve disease, right ventricular (RV) failure, pericardial disease, and patent foramen ovale. PRINCIPAL FINDINGS: Three hundred twenty-one studies were found using our search terms, and thirteen studies were retained that met our inclusion criteria for review. The studies included 968 patients analyzed as either preoperative exams in high-risk patients (n = 568) or intraoperative exams during times of hemodynamic compromise/cardiac arrest (n = 400). The most common diagnoses in the preoperative exam group were low ejection fraction (25.4%), aortic valve disease (24.4%), mitral valve disease (20.0%), RV failure (6.6%), and hypovolemia (6.3%). In the intraoperative exam group, the most common diagnoses were hypovolemia (33.2%), low ejection fraction (20.5%), RV failure (13.1%), SWMAs (10.1%), and PE (5.8%). CONCLUSION: In this systematic review examining the use of TTE or TEE in non-cardiac surgery, the most frequent diagnoses were valvulopathy, low LVEF, hypovolemia, PE, SWMAs, and RV failure. This information should be used to inform evidence-based curricula for POCU in anesthesiology.

Off-label use of recombinant activated factor VII in surgical and non-surgical patients at 16 Canadian hospitals from 2007 to 2010 (Canadian Registry Report).

PURPOSE: Recombinant activated factor VII (rFVIIa) is a pro-hemostatic drug that is approved for treatment of bleeding in hemophilia patients, but it is frequently used off-label in non-hemophiliacs. The purpose of this study was to determine if the off-label use of rFVIIa is expanding and whether this poses a net harm to patients. METHODS: For this historical cohort study, data were collected on all non-hemophilia patients who received rFVIIa from 2007 to 2010 at 16 Canadian centres, and the pattern of use was examined. Logistic regression was used to determine the prognostic importance of severity of bleeding and the presence of an rFVIIa dose-effect relationship with major adverse events. RESULTS: One thousand three hundred seventy-eight patients received rFVIIa off-label, and 987 (72%) of these patients underwent cardiac surgery. The median [interquartile range] dose was 57 [36-85] µg·kg(-1). Usage increased from 2007 to 2008 (n = 341 and 380, respectively) but decreased in 2009 and 2010 (n = 350 and 307, respectively). Dose of rFVIIa and bleeding severity were associated with measured adverse events (P < 0.05). After adjusting for bleeding severity, dose was not associated with any of the adverse events. CONCLUSIONS: The off-label use of rFVIIa in Canada remains stable. Since severity of bleeding is prognostically important, the benefits of rapidly gaining control of bleeding that is non-responsive to conventional therapies may at times warrant the use of potent hemostatic drugs with established risk profiles, such as rFVIIa.

The utility of transthoracic echocardiography to confirm central line placement: an observational study.

BACKGROUND: Ultrasound visualization of neck vessels is the standard method used to assist with internal jugular vein (IJV) central line placement. Nevertheless, this practice has not eliminated the risk of carotid puncture and/or inadvertent arterial cannulation. Transesophageal echocardiography (TEE) effectively verifies wire placement within the heart but is invasive and not always available. We examined the feasibility and potential utility of using transthoracic echocardiography (TTE) to verify the distal wire in the right atrium (RA) before dilation and cannulation of the IJV. METHODS: Following institutional Research Ethics Board approval and signed consent, 100 patients scheduled for elective cardiac surgery were recruited. As per standard practice at our institution, all patients were to have a central line inserted under general anesthesia with TEE visualization of the guidewire. Transesophageal echocardiography (apical or subcostal four-chamber images) was performed by one of four operators while another anesthesiologist performed central line placement. Following IJV puncture, blood was rapidly aspirated and reinjected to produce microbubbles. Subsequently, a 0.035-inch j-tipped flexible guidewire was inserted and visualized with TEE. The wire was then reinserted into the RA under TTE visualization. RESULTS: Overall, the RA was viewed 94% (95% confidence interval [CI] 87 to 98) of the time with TTE, and both the microbubbles and guidewire were detected 91% (95% CI 84 to 96) of the time. The subjects in whom the guidewire could not be well visualized had a higher mean body mass index (33.6 vs 28.8; P = 0.01). CONCLUSIONS: Transthoracic echocardiography [corrected] is a feasible, noninvasive, and potentially useful method to confirm appropriate placement of the guidewire before dilation and cannulation of the IJV.

Pain and inflammatory response following off-pump coronary artery bypass grafting.

PURPOSE OF REVIEW: Inflammation and pain are two common clinical issues following cardiac surgery, which are important to patient outcomes. This article reviews the literature regarding inflammation and pain following cardiac surgery with special emphasis on off-pump cardiac surgery. RECENT FINDINGS: Off-pump surgery is associated with decreased intraoperative inflammatory response compared with procedures using cardiopulmonary bypass; however, the postoperative pattern of inflammatory response is similar to on-pump procedures. Multimodal analgesic regimens and protocol-based approaches to pain management improve analgesia compared to conventional approaches. SUMMARY: Off-pump cardiac surgeries although known to decrease the inflammatory burden do not appear to impact the overall patient outcomes. Recent evidence indicates the prothrombotic tendency following off-pump procedures, which could be related to the time course of inflammation following off-pump cardiac surgery. There might be some benefit of off-pump procedures regarding neurological and renal function that needs further studies. Pain management following off-pump procedures is similar to that of patients undergoing on-pump cardiac surgery. Better caregiver and patient education is crucial for improving pain control following cardiac surgery. Analgesic regimens need to consider adjuvants and regional analgesic techniques and patient-controlled modalities while providing care.

Successful management of cold-induced urticaria during hypothermic circulatory arrest.

Cold-induced urticaria (CIU) is a potentially life-threatening immunologic disorder characterized by swelling and edema of exposed tissue in response to a cold stimulus. We describe the successful management of a patient with a history of severe CIU who required coronary bypass and repair of an ascending aortic aneurysm using hypothermic circulatory arrest.

A retrospective analysis of blood loss with combined topical and intravenous tranexamic acid after coronary artery bypass graft surgery.

OBJECTIVE: Intravenous antifibrinolytics are the gold standard for blood conservation during cardiac surgery. Recent evidence suggests that topical tranexamic acid administration also is effective, although the efficacy of combined topical and intravenous administration has never been reported. Combined administration may offer superior hemostasis while decreasing side effects. The current study explores the use of combined topical and intravenous tranexamic acid as a blood conservation strategy in cardiac surgery. DESIGN: Retrospective cohort. SETTING: A single-center, academic, tertiary care hospital. PARTICIPANTS: One hundred sixty elective coronary artery bypass graft patients. INTERVENTION: A practice change allowed a retrospective comparison of postoperative chest tube drainage in patients with intravenous or combined (intravenous and topical) tranexamic acid. MEASUREMENTS AND MAIN RESULTS: Chest tube drainage was decreased in the combined group at 3 (164.8 ± 102.2 v 242.7 ± 148.9 mL, p < 0.001), 6 (265.6 ± 163.7 v 358.8 ± 247.2 mL, p = 0.006), and 12 hours (374.3 ± 217.1 v 498.5 ± 336.6 mL, p = 0.006) postoperatively compared with the intravenous group. The tranexamic acid dose was higher in the combined group (5.1 ± 1.1 v 4.1 ± 1.3 g, p < 0.001), but less was administered intravenously (3.1 ± 1.1 v 4.1 ± 1.3 g, p < 0.001). No differences were observed in adverse events. CONCLUSIONS: This study suggested that combined tranexamic acid administration may be superior for blood conservation, but fully powered randomized controlled trials will be required to confirm these findings and determine the safety advantage and clinical relevance of adding topical tranexamic acid to existing blood conservation strategies.

Supplemental oxygen does not prevent postoperative nausea and vomiting after gynecological laparoscopy.

PURPOSE: Postoperative nausea and vomiting are among the most common and distressing side effects of general anesthesia. Supplemental intraoperative 80% oxygen reduces postoperative nausea and vomiting following open and laparoscopic abdominal surgery. However, this benefit has not been observed in other patient populations. We undertook this study to evaluate the effect of 80% supplemental intraoperative oxygen on the incidence of postoperative nausea and vomiting following ambulatory surgery for laparoscopic tubal ligation. METHODS: Following Research Ethics Board approval, 304 subjects were enrolled into one of two arms of a randomized prospective controlled study. The intervention group (n = 147) breathed 80% oxygen and the control group (n = 145) breathed routine 30% oxygen (balance medical air) while both groups were receiving a standardized general anesthetic. Nausea was assessed as: none, mild, moderate, or severe; vomiting was any emetic episode or retching. Any assessment either greater than none (nausea) or greater than zero (vomiting) was considered positive. RESULTS: The incidence of postoperative nausea and vomiting up to 24 hr following surgery was 69% in the 80% oxygen intervention group and 65% in the 30% oxygen control group (P = 0.62). There were no differences in nausea alone, vomiting, or antiemetic use in the postoperative anesthetic care unit or at any time (pre- or post-discharge) up to 24 hr after surgery. CONCLUSIONS: This trial of 304 women did not demonstrate that administering intraoperative supplemental 80% oxygen during ambulatory surgery for laparoscopic tubal ligation prevented postoperative nausea or vomiting during the initial postoperative 24 hr compared with women who received routine 30% oxygen.

Retrograde autologous priming and allogeneic blood transfusions: a meta-analysis.

A literature review and meta-analysis were undertaken to assess the clinical effectiveness of retrograde autologous priming of the cardiopulmonary bypass circuit to reduce allogeneic packed red blood transfusions in adult cardiac surgery. Structured searches of Medline, Embase, Cochrane Collaboration Library, Scopus, Cumulative Index to Nursing and Allied Health Literature and Science Direct were performed to identify randomized trials comparing retrograde autologous priming to a prospective control group. A total of 21,643 studies were identified and eighteen trials were retrieved for full-text review. Six trials met eligibility criteria. Pooled estimates demonstrated that retrograde autologous priming significantly reduced the number of patients receiving intraoperative packed red cell transfusions (OR=0.36; 95% CI: 0.13, 0.94; P=0.04, I(2)=47.5%), total hospital stay packed red cell transfusions (OR=0.26; 95% CI: 0.13, 0.52; P=0.0001, I(2)=0%), and the number of units transfused of total hospital stay packed red blood cells (WMD=-0.60; 95% CI: -0.90, -0.31; P=0.0001, I(2)=0%). Retrograde autologous priming, however, did not provide a clinical benefit in reducing the number of units transfused of intraoperative packed red blood cells (WMD=-0.29; 95% CI: -0.59, 0.01; P=0.05). The combined patient population studied in the six trials was mainly primary isolated coronary artery bypass surgery. Assessing the safety of retrograde autologous priming was not possible due to limited data.

Comprehensive Canadian review of the off-label use of recombinant activated factor VII in cardiac surgery.

BACKGROUND: This observational study sought to identify the off-label use pattern of recombinant activated factor VII (rFVIIa) in cardiac surgery and to identify predictors of its effectiveness and risk. METHODS AND RESULTS: At 18 Canadian centers, 522 nonhemophiliac cardiac surgical patients received rFVIIa during the period 2003 through 2006; data were available, and retrospectively collected, on 503 patients. The median (quartile 1, quartile 3) units of red blood cells transfused from surgery to therapy and in the 24 hours after therapy were 8 (5, 12) and 2 (1, 5), respectively (P<0.0001). Mortality rate was 32%, and mortality or major morbidity rate was 44%. These rates were within expected ranges (mortality, 27% to 35%; mortality or morbidity, 39% to 48%), which were calculated with a separate cohort of cardiac surgical patients who did not receive rFVIIa used as reference. Independent predictors of complications included instability before therapy (multiple inotropes or intra-aortic balloon pump) and increasing red blood cell units transfused before and after therapy. Variables independently associated with nonresponse included abnormal coagulation parameters and >15 red blood cell units transfused before therapy. CONCLUSIONS: In Canada, rFVIIa is used primarily when standard interventions have failed to control bleeding. In this setting, rFVIIa is associated with reduced blood product transfusions and, after risk adjustment, does not appear to be associated with increased or decreased complication rates. The effectiveness of the drug may be enhanced if it is given early in the course of refractory blood loss in the setting of adequate amounts of circulating coagulation factors.

A comparison of aprotinin and lysine analogues in high-risk cardiac surgery.

BACKGROUND: Antifibrinolytic agents are commonly used during cardiac surgery to minimize bleeding and to reduce exposure to blood products. We sought to determine whether aprotinin was superior to either tranexamic acid or aminocaproic acid in decreasing massive postoperative bleeding and other clinically important consequences. METHODS: In this multicenter, blinded trial, we randomly assigned 2331 high-risk cardiac surgical patients to one of three groups: 781 received aprotinin, 770 received tranexamic acid, and 780 received aminocaproic acid. The primary outcome was massive postoperative bleeding. Secondary outcomes included death from any cause at 30 days. RESULTS: The trial was terminated early because of a higher rate of death in patients receiving aprotinin. A total of 74 patients (9.5%) in the aprotinin group had massive bleeding, as compared with 93 (12.1%) in the tranexamic acid group and 94 (12.1%) in the aminocaproic acid group (relative risk in the aprotinin group for both comparisons, 0.79; 95% confidence interval [CI], 0.59 to 1.05). At 30 days, the rate of death from any cause was 6.0% in the aprotinin group, as compared with 3.9% in the tranexamic acid group (relative risk, 1.55; 95% CI, 0.99 to 2.42) and 4.0% in the aminocaproic acid group (relative risk, 1.52; 95% CI, 0.98 to 2.36). The relative risk of death in the aprotinin group, as compared with that in both groups receiving lysine analogues, was 1.53 (95% CI, 1.06 to 2.22). CONCLUSIONS: Despite the possibility of a modest reduction in the risk of massive bleeding, the strong and consistent negative mortality trend associated with aprotinin, as compared with the lysine analogues, precludes its use in high-risk cardiac surgery. (Current Controlled Trials number, ISRCTN15166455 [controlled-trials.com].).

A triple-blinded randomized trial comparing the hemostatic effects of large-dose 10% hydroxyethyl starch 264/0.45 versus 5% albumin during major reconstructive surgery.

In Canada, hydroxyethyl starch 264/0.45 (HES 264/0.45; molar weight 264 kDa, molar substitution 0.45) has largely replaced albumin as the colloidal fluid of choice for perioperative intravascular volume expansion. The maximum recommended dose of HES 264/0.45 is 28 mL/kg; however, there are no clinical data supporting this limit. In this study we compared the hemostatic effects of HES 264/0.45 versus 5% albumin in doses up to 45 mL/kg over 24 h during major reconstructive head and neck surgery. Fifty patients were randomized to receive HES 264/0.45 or 5% human albumin from the induction of anesthesia until 24 h thereafter. Both albumin and HES 264/0.45 effectively maintained physiologic variables in the perioperative and postoperative periods. The partial thromboplastin time and international normalized ratio were significantly increased in the HES 264/0.45 group compared with the albumin group after infusion of 30 mL/kg and 45 mL/kg (P < 0.05). Factor VIII activity and von Willebrand factor level were significantly reduced in the HES 264/0.45 group compared with the albumin group after infusion of 15 mL/kg, 30 mL/kg, and 45 mL/kg (P < 0.05). Significantly more subjects in the HES 264/0.45 group received allogeneic red blood cell transfusions (P < 0.02). We conclude that HES 264/0.45 infusions >30 mL/kg over 24 h impair coagulation to a greater extent than albumin, possibly leading to more allogeneic transfusions.

Transfusion practices for elective orthopedic surgery.

BACKGROUND: Use of blood conservation techniques in elective surgery reduces the risk of infection and transfusion reactions that result from using allogeneic blood products. We examined the transfusion practice and blood conservation strategies for elective orthopedic procedures in 19 Canadian hospitals. METHODS: We reviewed the medical records of patients who underwent total hip or knee joint arthroplasty between June 1998 and January 1999 in a convenience sample of 19 hospitals to determine the pre- and postoperative hemoglobin concentrations, concurrent medical conditions, participation status in an autologous blood donation program, use of other blood conservation techniques, and occurrence of allogeneic and autologous transfusions. Patients were considered eligible for autologous blood donation if they weighed at least 25 kg, were in good general health without major cardiac conditions and had a hemoglobin concentration of at least 110 g/L. RESULTS: We reviewed 4535 medical records. Of the 4422 patients whose eligibility status was known, 2561 (57.9%) were eligible to participate in an autologous blood donation program. Only 842 (18.6%) of the patients predonated blood. Patients who did not predonate blood were older (mean age 70.1 v. 63.8 years) and were more likely to have concomitant medical conditions (60.3% v. 37.9%) than those who did predonate. Overall, 30.6% (95% confidence interval [CI] 29.1%-32.1%) of the patients who did not predonate blood received allogeneic transfusions. For patients who predonated, the rate of allogeneic transfusion was 14.1% (95% CI 11.8%-16.5%). The frequency with which blood conservation techniques other than autologous blood donation were used was minimal (in 2.4% of all cases). INTERPRETATION: The use of blood conservation techniques among hospitals in Canada remains low. Only a minority of eligible patients participated in an autologous blood donation program.