Wireless continuous single-lead ST-segment monitoring to detect new-onset myocardial injury at the general ward-An exploratory subanalysis.

Patients admitted for acute medical conditions and major noncardiac surgery are at risk of myocardial injury. This is frequently asymptomatic, especially in the context of concomitant pain and analgesics, and detection thus relies on cardiac biomarkers. Continuous single-lead ST-segment monitoring from wireless electrocardiogram (ECG) may enable more timely intervention, but criteria for alerts need to be defined to reduce false alerts. This study aimed to determine optimal ST-deviation thresholds from wireless single-lead ECG for detection of myocardial injury following major abdominal cancer surgery and during acute exacerbation of chronic obstructive pulmonary disease. Patients were monitored with a wireless single-lead ECG patch for up to 4 days and had daily troponin measurements. Single-lead ST-segment deviations of <0.255 mV and/or >0.245 mV (based on previous study comparison with 0.1 mV 12-lead ECG and variation in single-lead ECG) were analyzed for relation to myocardial injury defined as hsTnT elevation of 20-64 ng/L with an absolute change of ≥5 ng/L, or a hsTnT level ≥ 65 ng/L. In total, 528 patients were included for analysis, of which 15.5% had myocardial injury. For corrected ST-thresholds lasting ≥10 and ≥ 20 min, we found specificities of 91% and 94% and sensitivities of 17% and 13% with odds ratios of 2.0 (95% CI: 1.1; 3.9) and 2.4 (95% CI: 1.1; 5.1) for myocardial injury. In conclusion, wireless single-lead ECG monitoring with corrected ST thresholds detected patients developing myocardial injury with specificities >90% and sensitivities <20%, suggesting increased focus on sensitivity improvement.

Workload associated with manual assessment of vital signs as compared with continuous wireless monitoring.

BACKGROUND: Vital sign monitoring is considered an essential aspect of clinical care in hospitals. In general wards, this relies on intermittent manual assessments performed by clinical staff at intervals of up to 12 h. In recent years, continuous monitoring of vital signs has been introduced to the clinic, with improved patient outcomes being one of several potential benefits. The aim of this study was to determine the workload difference between continuous monitoring and manual monitoring of vital signs as part of the National Early Warning Score (NEWS). METHODS: Three wireless sensors continuously monitored blood pressure, heart rate, respiratory rate, and peripheral oxygen saturation in 20 patients admitted to the general hospital ward. The duration needed for equipment set-up and maintenance for continuous monitoring in a 24-h period was recorded and compared with the time spent on manual assessments and documentation of vital signs performed by clinical staff according to the NEWS. RESULTS: The time used for continuous monitoring was 6.0 (IQR 3.2; 7.2) min per patient per day vs. 14 (9.7; 32) min per patient per day for the NEWS. Median difference in duration for monitoring of vital signs was 9.9 (95% CI 5.6; 21) min per patient per day between NEWS and continuous monitoring (p < .001). Time used for continuous monitoring in isolated patients was 6.6 (4.6; 12) min per patient per day as compared with 22 (9.7; 94) min per patient per day for NEWS. CONCLUSION: The use of continuous monitoring was associated with a significant reduction in workload in terms of time for monitoring as compared with manual assessment of vital signs.

The effect of technical filtering and clinical criteria on alert rates from continuous vital sign monitoring in the general ward.

OBJECTIVES: Continuous vital sign monitoring at the general hospital ward has major potential advantages over intermittent monitoring but generates many alerts with risk of alert fatigue. We hypothesized that the number of alerts would decrease using different filters. METHODS: This study was an exploratory analysis of the alert reducing effect from adding two different filters to continuously collected vital sign data (peripheral oxygen saturation, blood pressure, heart rate, and respiratory rate) in patients admitted after major surgery or severe medical disease. Filtered data were compared to data without artifact removal. Filter one consists of artifact removal, filter two consists of artifact removal plus duration criteria adjusted for severity of vital sign deviation. Alert thresholds were based on the National Early Warning Score (NEWS) threshold. RESULTS: A population of 716 patients admitted for severe medical disease or major surgery with continuous wireless vital sign monitoring at the general ward with a mean monitoring time of 75.8 h, were included for the analysis. Without artifact removal, we found a median of 137 [IQR: 87-188] alerts per patient/day, artifact removal resulted in a median of 101 [IQR: 56-160] alerts per patient/day and with artifact removal combined with a duration-severity criterion, we found a median of 19 [IQR: 9-34] alerts per patient/day. Reduction of alerts was 86.4% (p < 0.001) for values without artifact removal (137 alerts) vs. the duration criteria and a reduction (19 alerts) of 81.5% (p < 0.001) for the criteria with artifact removal (101 alerts) vs. the duration criteria (19 alerts). CONCLUSION: We conclude that a combination of artifact removal and duration-severity criteria approach substantially reduces alerts generated by continuous vital sign monitoring.

Deviations in continuously monitored electrodermal activity before severe clinical complications: a clinical prospective observational explorative cohort study.

Monitoring of high-risk patients in hospital wards is crucial in identifying and preventing clinical deterioration. Sympathetic nervous system activity measured continuously and non-invasively by Electrodermal activity (EDA) may relate to complications, but the clinical use remains untested. The aim of this study was to explore associations between deviations of EDA and subsequent serious adverse events (SAE). Patients admitted to general wards after major abdominal cancer surgery or with acute exacerbation of chronic obstructive pulmonary disease were continuously EDA-monitored for up to 5 days. We used time-perspectives consisting of 1, 3, 6, and 12 h of data prior to first SAE or from start of monitoring. We constructed 648 different EDA-derived features to assess EDA. The primary outcome was any SAE and secondary outcomes were respiratory, infectious, and cardiovascular SAEs. Associations were evaluated using logistic regressions with adjustment for relevant confounders. We included 714 patients and found a total of 192 statistically significant associations between EDA-derived features and clinical outcomes. 79% of these associations were EDA-derived features of absolute and relative increases in EDA and 14% were EDA-derived features with normalized EDA above a threshold. The highest F1-scores for primary outcome with the four time-perspectives were 20.7-32.8%, with precision ranging 34.9-38.6%, recall 14.7-29.4%, and specificity 83.1-91.4%. We identified statistically significant associations between specific deviations of EDA and subsequent SAE, and patterns of EDA may be developed to be considered indicators of upcoming clinical deterioration in high-risk patients.

Continuous monitoring is superior to manual measurements in detecting vital sign deviations in patients with COVID-19.

BACKGROUND: Patients admitted to the emergency care setting with COVID-19-infection can suffer from sudden clinical deterioration, but the extent of deviating vital signs in this group is still unclear. Wireless technology monitors patient vital signs continuously and might detect deviations earlier than intermittent measurements. The aim of this study was to determine frequency and duration of vital sign deviations using continuous monitoring compared to manual measurements. A secondary analysis was to compare deviations in patients admitted to ICU or having fatal outcome vs. those that were not. METHODS: Two wireless sensors continuously monitored (CM) respiratory rate (RR), heart rate (HR), and peripheral arterial oxygen saturation (SpO2 ). Frequency and duration of vital sign deviations were compared with point measurements performed by clinical staff according to regional guidelines, the National Early Warning Score (NEWS). RESULTS: SpO2 < 92% for more than 60 min was detected in 92% of the patients with CM vs. 40% with NEWS (p < .00001). RR > 24 breaths per minute for more than 5 min were detected in 70% with CM vs. 33% using NEWS (p = .0001). HR ≥ 111 for more than 60 min was seen in 51% with CM and 22% with NEWS (p = .0002). Patients admitted to ICU or having fatal outcome had longer durations of RR > 24 brpm (p = .01), RR > 21 brpm (p = .01), SpO2 < 80% (p = .01), and SpO2 < 85% (p = .02) compared to patients that were not. CONCLUSION: Episodes of desaturation and tachypnea in hospitalized patients with COVID-19 infection are common and often not detected by routine measurements.

Laser Speckle Contrast Imaging-based diagnosis of severe mesenteric traction syndrome: Hemodynamics and prostacyclin - A prospective cohort study.

BRIEF ABSTRACT: Today, the diagnosis and grading of mesenteric traction syndrome relies on a subjective assessment of facial flushing. However, this method has several limitations. In this study, Laser Speckle Contrast Imaging and a predefined cut-off value are assessed and validated for the objective identification of severe mesenteric traction syndrome. BACKGROUND: Severe mesenteric traction syndrome (MTS) is associated with increased postoperative morbidity. The diagnosis is based on an assessment of the developed facial flushing. Today this is performed subjectively, as no objective method exists. One possible objective method is Laser Speckle Contrast Imaging (LSCI), which has been used to show significantly higher facial skin blood flow in patients developing severe MTS. Using these data, a cut-off value has been identified. This study aimed to validate our predefined LSCI cut-off value for identifying severe MTS. METHODS: A prospective cohort study was performed on patients planned for open esophagectomy or pancreatic surgery from March 2021 to April 2022. All patients underwent continuous measurement of forehead skin blood flow using LSCI during the first hour of surgery. Using the predefined cut-off value, the severity of MTS was graded. In addition, blood samples for prostacyclin (PGI2) analysis and hemodynamics were collected at predefined time points to validate the cut-off value. MAIN RESULTS: Sixty patients were included in the study. Using our predefined LSCI cut-off value, 21 (35 %) patients were identified as developing severe MTS. These patients were found to have higher concentrations of 6-Keto-PGFaα (p = 0.002), lower SVR (p < 0.001), lower MAP (p = 0.004), and higher CO (p < 0.001) 15 min into surgery, as compared with patients not developing severe MTS. CONCLUSION: This study validated our LSCI cut-off value for the objective identification of severe MTS patients as this group developed increased concentrations of PGI2 and more pronounced hemodynamic alterations compared with patients not developing severe MTS.

Robot-assisted laparoscopic radical cystectomy with intracorporeal ileal conduit diversion versus open radical cystectomy with ileal conduit for bladder cancer in an ERAS setup (BORARC): protocol for a single-centre, double-blinded, randomised feasibility study.

BACKGROUND: Radical cystectomy (RC) with urinary diversion is the recommended treatment for selected cases of non-metastatic high-risk non-muscle-invasive and muscle-invasive bladder cancer. It remains unknown whether robot-assisted laparoscopic cystectomy (RARC) offers any advantage in terms of safety compared to open cystectomy (ORC) in an Enhanced Recovery After Surgery (ERAS) setup. Blinded randomised controlled trials (RCTs) between RARC versus ORC have never been conducted in cystectomy patients. We will investigate the feasibility of conducting a double-blinded RCT comparing ORC with RARC with intra-corporal ileal conduit (iRARC) in an ERAS setup. METHODS: This is a single-centre, double-blinded, randomised (1:1) clinical feasibility study for patients with non-metastatic high-risk non-muscle-invasive or muscle-invasive bladder cancer scheduled for cystectomy. All participants are recruited from Rigshospitalet, Denmark. The planned sample size is 50 participants to investigate whether blinding of the surgical technique is feasible. Participants and postoperative caring physicians and nurses are blinded using a pre-study designed abdominal dressing and blinding of the patient's electronic health record. Study endpoints are assessed 90 days postoperatively. The primary aim is to study the frequency and pattern of unplanned unblinding after surgery and the number of participants who cannot guess the surgical technique at the day of discharge. Eleven secondary endpoints are assessed: length of stay, days alive and out of hospital, in-hospital complication rate, 30-day complication rate, 90-day complication rate, readmission rate, quality of life, blood loss, pain, rate of moderate/severe post-anaesthesia care unit (PACU) complications, and delirium. Participants are managed in an ERAS setup in both arms of the trial. DISCUSSION: We report on the design and objectives of a novel experimental feasibility study investigating whether blinding of the surgical technique in cystectomy patients is possible. This information is essential for the design of future blinded trials comparing ORC to RARC. There is a continued need to compare RARC and ORC in terms of both efficacy, safety, and oncological outcomes. Estimated end of study is March 2021. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT03977831. Registered on the 6th of June 2019.

Continuous wireless pre- and postoperative vital sign monitoring reveal new, severe desaturations after vascular surgery.

OBJECTIVES: Postoperative deviating physiologic values (vital signs) may represent postoperative stress or emerging complications. But they can also reflect chronic preoperative values. Distinguishing between the two circumstances may influence the utility of using vital signs in patient monitoring. Thus, we aimed to describe the occurrence of vital sign deviations before and after major vascular surgery, hypothesising that preoperative vital sign deviations were longer in duration postoperatively. METHODS: In this prospective observational study, arterial vascular patients were continuously monitored wirelessly - from the day before until 5 days after surgery. Recorded values were: heart rate, respiration rate, peripheral arterial oxygen saturation (SpO2 ) and blood pressure. The outcomes were 1. cumulative duration of SpO2 < 85% / 24 h, and 2. cumulative duration per 24 h of vital sign deviations. RESULTS: Forty patients were included with a median monitoring time of 21 h preoperatively and 42 h postoperatively. The median duration of SpO2 < 85% preoperatively was 14.4 min/24 h whereas it was 28.0 min/24 h during day 0 in the ward (p = .09), and 16.8 min/24 h on day 1 in the ward (p = 0.61). Cumulative duration of SpO2 < 80% was significantly longer on day 0 in the ward 2.4 min/24 h (IQR 0.0-4.6) versus 6.7 min/24 h (IQR 1.8-16.2) p = 0.01. CONCLUSION: Deviating physiology is common in patients before and after vascular surgery. A longer duration of severe desaturation was found on the first postoperative day in the ward compared to preoperatively, whereas moderate desaturations were reflected in postoperative desaturations. Cumulative duration outside thresholds is, in some cases, exacerbated after surgery.

Simulation-Based Education of Endovascular Scrub Nurses Reduces Stress and Improves Team Performance.

INTRODUCTION: Endovascular procedures have become commonplace in vascular surgery. This development calls for new training strategies for future specialists. Most simulation-based education (SBE) programs have a monodisciplinary focus on physicians, although successful surgery is a multidisciplinary team effort. Mental stress impairs the learning process and surgical performance and heart rate variability (HRV) can be measured as a proxy for both mental and physical stress. This study aims to assess how SBE of endovascular scrub nurses affects team performance and HRV during endovascular aneurysm repair (EVAR). MATERIALS AND METHODS: Prospective interventional study in which EVAR-inexperienced scrub nurses followed a focused SBE EVAR program. During real-life EVAR procedures, HRV was continuously recorded with a wireless electrocardiogram patch and multidisciplinary team performance was assessed with the Imperial College Error CAPture (ICECAP) tool, before and after the SBE program, allowing each scrub nurse to serve as their own control. Eight scrub nurses with experience in lower limb endovascular procedures, but not EVAR, were invited to participate. RESULTS: Seven participants completed the study. In five of seven scrub nurses, HRV-derived stress levels during real-time EVAR procedures were lower after SBE compared to before SBE. Mean HRV increased from 24 msec to 35 msec (P < 0.001), indicating stress level reduction. Before SBE, the mean number of errors/hour was 7.3 (standard deviation ± 1.8) compared to 3.6 (standard deviation ± 2.7) after SBE. Most errors were categorized as technical (58 %) and communicative (23 %). CONCLUSIONS: SBE of scrub nurses may improve team performance and may lower mental stress during EVAR procedures. In this small study, we suggest using mental stress, as evaluated with HRV, and multidisciplinary team performance, as evaluated with ICECAP, to assess SBE effectiveness in real-case EVAR procedures. This SBE program and live ICECAP observations and electrocardiogram patches was well-accepted by scrub nurses and the entire team.

Transcutaneous blood gas monitoring and tissue perfusion during common femoral thromboendarterectomy.

BACKGROUND: Improving tissue perfusion can improve clinical outcomes in surgical patients, where monitoring may aid clinicians in detecting adverse conditions and guide interventions. Transcutaneous monitoring (TCM) of oxygen (tcpO2) and carbon dioxide (tcpCO2) is a well-proven technology and could potentially serve as a measure of local circulation, perfusion and metabolism, but the clinical use is not thoroughly explored. The purpose of this proof-of-concept study was to investigate whether TCM of blood gasses could detect changes in perfusion during major vascular surgery. METHODS: Ten patients with peripheral arterial disease scheduled for lower limb major arterial revascularization under general anaesthesia were consecutively included. TcpO2 and tcpCO2 were continuously recorded from anaesthesia induction until skin closure with a TCM monitor placed on both legs and the thorax. Peripheral oxygen saturation was kept ≥94% and mean arterial blood pressure ≥65 mmHg. The primary outcomes were changes in tcpO2 and tcpCO2 related to arterial clamping and declamping during the procedure and analyzed by paired statistics. RESULTS: Femoral artery clamping resulted in a significant decrease in tcpO2 (-2.1 kPa, IQR-4.2; -0.8), p=.017)), followed by a significant increase in response to arterial declamping (5.5 kPa, IQR 0-7.3), p=.017)). Arterial clamping resulted in a statistically significant increase in tcpCO2 (0.9 kPa, IQR 0.3-5.4), p=.008)) and a significant decrease following declamping (-0.7 kPa, IQR -2.6; -0.2), p=.011)). CONCLUSION: Transcutaneous monitoring of oxygen and carbon dioxide is a feasible method for detection of extreme changes in tissue perfusion during arterial clamping and declamping, and its use for improving patient outcomes should be explored. Clinical Trials identifier: NCT04040478. Registered on July 31, 2019.

Quality of life and secondary outcomes for open versus robot-assisted radical cystectomy: a double-blinded, randomised feasibility trial.

PURPOSE: This study aims to examine quality of life (QoL) before and after radical cystectomy (RC) and compare robot-assisted laparoscopy with intracorporeal urinary diversion (iRARC) to open radical cystectomy (ORC). METHODS: This study is a predefined secondary analysis of a single-centre, double-blinded, randomised feasibility trial. Fifty patients were randomly assigned to iRARC with ileal conduit (n = 25) or ORC with ileal conduit (n = 25). Patients were followed 90 days postoperatively. The primary outcome was patient-reported QoL using the EORTC Cancer-30 and muscle-invasive bladder cancer BLM-30 QoL questionnaires before and after RC. Differences between randomisation arms as well as changes over time were evaluated. Secondary outcomes included 30- and 90 day complication rates, 90 day readmission rates, and 90 day days-alive-and-out-of-hospital and their relationship to QoL. RESULTS: All patients underwent the allocated treatment. We found no difference in QoL, complication rates, readmission rates, and days-alive-and-out-of-hospital between randomisation arms. An overall improvement in QoL was found in the following domains: future perspectives, emotional functioning, and social functioning. Sexual functioning worsened postoperatively. There was no association between having experienced a major complication or lengthy hospitalisation and worse postoperative QoL. CONCLUSION: The QoL does not appear to depend on surgical technique. Apart from sexual functioning, patients report stable or improved QoL within the first 90 postoperative days.

High-dose preoperative glucocorticoid for prevention of emergence and postoperative delirium in liver resection: A double-blinded randomized clinical trial substudy.

BACKGROUND: Emergence delirium (ED) and postoperative delirium (POD) are associated with increased morbidity and mortality and occur in up to one-third of patients undergoing major non-cardiac surgery, where the underlying pathogenesis is multifactorial, including increased inflammation. We aimed to assess the effect of pre-operative high- versus low-dose glucocorticoid on the occurrence of ED and POD. METHODS: This was a substudy from a randomized, double-blinded clinical trial. Patients ≥18 years, undergoing open liver resection were randomized 1:1 to high-dose (HD, 10 mg/kg methylprednisolone) or low-dose (LD, 8 mg dexamethasone) glucocorticoid and assessed for ED and POD for a maximum of 4 days during hospitalization. The 3-min Diagnostic Interview for CAM-defined delirium (3D-CAM) was used for assessment, 15 and 90 min after arrival in the post-anesthesia care unit (PACU), and subsequently once daily in the ward. RESULTS: Fifty-three patients were included in this secondary substudy (26 HD-group and 27 LD-group). ED occurred in n = 5 HD versus n = 6 LD patients 15 min after PACU arrival. At 90 min after PACU arrival, 4 patients had ED, all from LD-group, and resulted in significantly longer PACU admission, 273 versus 178 min in ED versus Non-ED patients. During the first 4 days in the ward, n = 5 patients had at least one occurrence of POD, all from LD-group. CONCLUSIONS: The primary finding of the current substudy was a lower occurrence of ED/POD in the PACU 90 min after arrival and during the first four postoperative days in patients receiving high-dose glucocorticoid compared with patients receiving low-dose glucocorticoid. The two study groups were not evenly balanced concerning known explanatory factors, i.e., age and size of surgery, which calls for larger studies to elucidate the matter.

Early postoperative recovery after peri-acetabular osteotomy: A double-blind, randomised single-centre trial of 48 vs. 8 mg dexamethasone.

BACKGROUND: Peri-acetabular osteotomy is the joint-preserving treatment of choice in young adults with hip dysplasia but is associated with intense pain and high opioid consumption postoperatively. OBJECTIVES: To investigate whether 48 mg of pre-operative dexamethasone was superior to a standard dose of 8 mg on reducing pain in the immediate postoperative phase. DESIGN: A randomised, double-blind trial. SETTING: Single-centre, primary facility. May 2017 to August 2019. PATIENTS: At least 18 years undergoing peri-acetabular osteotomy. INTERVENTIONS: Patients were randomised 1 : 1 to 48 or 8 mg dexamethasone intravenous (i.v.) as a single pre-operative injection. All patients received a standardised peri-operative protocol, including pre-operative acetaminophen and gabapentin, total i.v. anaesthesia and local anaesthetic catheter based wound administration. MAIN OUTCOME MEASURE: Number of patients with moderate/severe pain [>3 on a numeric rating scale (NRS)] in the immediate postoperative phase. RESULTS: Sixty-four patients (32 in each group) were included, and their data analysed. At some point from tracheal extubation until transfer to the ward, the NRS was more than 3 in 75% (24/32) of the 48 mg group and in 66% (21/32) in the 8 mg group, odds ratio 1.571 (95% CI, 0.552 to 4.64), P = 0.585. Patients in the 48 mg group received less opioid [cumulative rescue analgesics, oral morphine equivalents (OMEQ)] during postoperative days 0-4: median [IQR] OMEQ was 36 [15 to 85] mg vs. 79 [36 to 154] mg in the 48 and 8 mg group, respectively, P = 0.034. There were no statistically significant differences regarding complications, rate of infections or readmissions. CONCLUSION: Forty-eight milligram of dexamethasone did not reduce pain in the immediate postoperative phase compared with an 8 mg dose. We observed insignificantly lower pain scores and significantly lower cumulated opioid requirements in the 48 mg group during the first four postoperative days. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03161938, EudraCT (2017-000544-1).

Dexamethasone Dose and Early Postoperative Recovery after Mastectomy: A Double-blind, Randomized Trial.

BACKGROUND: Pain and nausea are the most common challenges in postoperative recovery after mastectomy. Preventive measures include multimodal analgesia with preoperative glucocorticoid. The aim of this study was to investigate whether 24 mg of preoperative dexamethasone was superior to 8 mg on early recovery after mastectomy in addition to a simple analgesic protocol. METHODS: In a randomized, double-blind trial, patients 18 yr of age or older having mastectomy were randomized 1:1 to 24 mg or 8 mg dexamethasone, and all received a standardized anesthetic and surgical protocol with preoperative acetaminophen, total intravenous anesthesia, and local anesthetic wound infiltration. The primary endpoint was number of patients transferred to the postanesthesia care unit according to standardized discharge criteria (modified Aldrete score). Secondary endpoints included pain and nausea at extubation, transfer from the operating room and upon arrival at the ward, length of stay, seroma occurrence, and wound infections. RESULTS: One hundred thirty patients (65 in each group) were included and analyzed for the primary outcome. Twenty-three (35%) in each group met the primary outcome, without significant differences in standardized discharge scores (odds ratio, 1.00 [95% CI, 0.49 to 2.05], P > 0.999). More patients had seroma requiring drainage in the 24 mg versus 8 mg group, 94% versus 81%, respectively (odds ratio, 3.53 [95% CI, 1.07 to 11.6], P = 0.030). Median pain scores were low at all measured time points, numeric rating scale less than or equal to 2 versus less than or equal to 1 in the 24 mg versus 8 mg group, respectively. Six patients in each group (9%) experienced nausea at any time during hospital stay (P > 0.999). Length of stay was median 11 and 9.2 h in the 24 and 8 mg group, respectively (P = 0.217). CONCLUSIONS: The authors found no evidence of 24 mg versus 8 mg of dexamethasone affecting the primary outcome regarding immediate recovery after mastectomy. The authors observed a short length of stay and low pain scores despite a simple analgesic protocol.

Postoperative cognitive dysfunction is rare after fast-track hip- and knee arthroplasty - But potentially related to opioid use.

STUDY OBJECTIVE: Postoperative cognitive dysfunction (POCD) remains a frequent postoperative complication in non-fast-track surgeries, with negative implications for return to daily activities and work. In fast-track total hip and -knee arthroplasty (THA/TKA) an 8-9% incidence of POCD after 3 months has been reported, but without details on specific perioperative risk factors. Thus, we re-investigated the incidence and role of suggested factors for POCD in a well-controlled patient cohort, to guide future preventive interventions. DESIGN: A subanalysis of a prospective study. SETTING: Hospital ward, patients own home. PATIENTS: One-hundred-and-four patients undergoing elective THA/TKA. INTERVENTIONS: A full contextual and validated cognitive test battery pre- and 2-3 weeks postoperatively by interview by research nurse. MEASUREMENTS: Results from the cognitive test battery were corrected for learning effect by normative data from an age-matched unoperated control group. Potential perioperative risk factors (age, procedure, gender, inflammation, blood-percentage, opioids etc.) associated with POCD was investigated by univariate and multivariate logistic analysis, with a 5% significance level. MAIN RESULTS: Four patients (3.9%) developed POCD. POCD-positive patients consumed higher dose of opioids in the acute postoperative period (postoperative days 0-3: median 214 mg), vs. POCD-negative patients (postoperative days 0-3: median 98 mg, p = 0.008), and during the 2-3-week study period (POCD-positive vs. POCD-negative patients, median 739 mg vs. 208 mg, respectively). Other pre and postoperative factors were non-significant but associated with the development of POCD. CONCLUSION: POCD is rare in fast-track THA/TKA patients and may be related to postoperative opioid consumption, supporting the ongoing focus on opioid-sparing analgesia.

Objectively measured early physical activity after total hip or knee arthroplasty.

Although reduced early physical function after total hip- and knee arthroplasty (THA/TKA) is well-described, the underlying reasons have not been clarified with detailed studies on pathophysiological mechanisms related to recovery, thereby prohibiting advances in rehabilitation. Thus, we aimed to describe early post-THA/TKA physical activity measured by actigraphy and potential underlying pathophysiological mechanisms related to recovery in a well-defined cohort of THA and TKA patients. Daytime-activity was measured from 2 days before until 13 (THA) or 20 (TKA) days after surgery. The primary outcome was individualized recovery in activity, with secondary analyses of activity-intensities and association to the perioperative factors: sex, age, BMI, hemoglobin (hgb), C-reactive protein and postoperative pain. Eighty-one THA/TKA-patients were examined. A large inter-individual variation in early physical activity was found. On a group level, activity was significantly reduced compared to preoperatively the first 2 (THA) or 3 (TKA) weeks after surgery (mean-difference - 64 counts × 103/day, p < 0.001 and - 78 counts × 103/day, p < 0.001, respectively). All activity-intensities were affected with the largest decline in high intense activity. A slight overall improvement in activity was seen during the postoperative phase [THA: 1%/day (SD 2.15); TKA: 0.7%/day (SD 1.04)], but approximately 30% of THA and 20% of TKA patients had reduced and declining activity. Hgb, CRP, BMI (THA) and postoperative pain (TKA) were only weakly associated with impaired physical activity. Physical activity was reduced the first weeks following THA/TKA, but with large inter-individual variations in recovery profiles. No single pathogenic factor was associated with a poor recovery. Early risk stratified interventions are needed in patients on a suboptimal course.

Acute complications in the post-anaesthesia care unit after infrainguinal surgery for lower limb ischaemia - a prospective observational cohort study.

BACKGROUND: Arterial surgery for lower limb ischaemia is a frequently performed procedure in patients with severe cardio-pulmonary comorbidities, making them high-risk patients for acute postoperative complications with a need for prolonged stay in the post-anaesthesia care unit (PACU). However, detailed information on complications during the PACU stay is limited, hindering mechanism-based interventions for early enhanced recovery. Thus, we aimed to systematically describe acute complications and related risk factors in the immediate postoperative phase after infrainguinal arterial surgery. PATIENTS AND METHODS: Patients transferred to the PACU after infrainguinal arterial surgery due to chronic or acute lower limb ischaemia were consecutively included in a six-month observational cohort study. Pre- and intraoperative data included comorbidities as well as surgical and anaesthetic technique. Data on complications and treatments in the PACU were collected every 15 minutes using a standardised assessment tool. The primary endpoint was occurrence of predefined moderate or severe complications occurring during PACU stay. RESULTS: In total, 155 patients were included for analysis. Eighty (52 %) patients experienced episodes with oxygen desaturation (< 85 %) and moderate or severe pain occurred in 72 patients (47 %); however, circulatory complications (hypotension, tachycardia) were rare. Preoperative opioid use was a significant risk factor for moderate or severe pain in PACU (59 vs. 38 % chronic vs. opioid naïve patients (P = 0.01). CONCLUSIONS: Complications in the PACU after infrainguinal arterial surgery relates to saturation and pain, suggesting that future efforts should focus on anaesthesia and analgesic techniques including opioid sparing regimes to enhance early postoperative recovery.

Towards an automated multimodal clinical decision support system at the post anesthesia care unit.

BACKGROUND: The aim of this study was to develop a predictive algorithm detecting early signs of deterioration (ESODs) in the post anesthesia care unit (PACU), thus being able to intervene earlier in the future to avoid serious adverse events. The algorithm must utilize continuously collected cardiopulmonary vital signs and may serve as an alternative to current practice, in which an alarm is activated by single parameters. METHODS: The study was a single center, prospective cohort study including 178 patients admitted to the PACU after major surgical procedures. Peripheral blood oxygenation, arterial blood pressure, perfusion index, heart rate and respiratory rate were monitored continuously. Potential ESODs were automatically detected and scored by two independent experts with regards to the severity of the observation. Based on features extracted from the obtained measurements, a random forest classifier was trained, classifying each event being either an ESOD or not an ESOD. The algorithm was evaluated and compared to the automated single modality alarm system at the PACU. RESULTS: The algorithm detected ESODs with an accuracy of 92.2% (99% CI: 89.6%-94.8%), sensitivity of 90.6% (99% CI: 85.7%-95.5%), specificity of 93.0% (99% CI: 89.9%-96.2%) and area under the receiver operating characteristic curve of 96.9% (99% CI: 95.3%-98.5%). The number of false alarms decreased by 85% (99% CI: 77%-93%) and the number of missed ESODs decreased by 73% (99% CI: 61%-85%) as compared to the currently used alarm system in the hospital. The algorithm was able to detect an ESOD in average 26.4 (99% CI: 1.1-51.7) minutes before the current single parameter system used in the PACU. CONCLUSION: In conclusion, the proposed biomedical classification algorithm, when compared to the currently used single parameter alarm system of the hospital, showed significantly increased performance in both detecting ESODs fast and classifying these correctly. The clinical effect of the predictive system must be evaluated in future trials.

The Relationship Between Sensory Loss and Persistent Pain 1 Year After Breast Cancer Surgery.

Moderate to severe persistent pain after breast cancer surgery (PPBCS) affects 10 to 20% of the patients. Sensory dysfunction is often concomitantly present suggesting a neuropathic pain state. The relationship between various postoperative pain states and sensory dysfunction has been examined using quantitative sensory testing (QST), but only 2 smaller studies have examined PPBCS and sensory dysfunction in the surgical area. The purpose of this prospective study was to assess the relative importance of sensory function and PPBCS. QST consisted of sensory mapping, tactile detection threshold, mechanical pain threshold, and thermal thresholds. Two hundred ninety patients were enrolled and results showed that 38 (13%) had moderate to severe pain and 246 (85%) had hypoesthesia in the surgical area 1 year after surgery. Increased hypoesthesia areas were associated with pain at rest as well as during movement (P = .0001). Pain during movement was associated with a side-to-side difference of 140% (P = .001) for tactile detection threshold and 40% (P = .01) for mechanical pain threshold as well as increased thermal thresholds in the axilla (P > .001). Logistic regression models controlling for confounders showed larger areas of hypoesthesia as a significant risk factor, odds ratio 1.85 per 100 cm2 for pain at rest and odds ratio 1.36 per 100 cm2 for pain during movement. PERSPECTIVE: PPBCS is associated with increasing areas of hypoesthesia as well as intraoperative nerve preservation. Thus, we hypothesize that PPBCS is associated with an interaction between a peripheral nociceptive drive in macroscopically preserved nerves and the central nervous system causing PPBCS as well as hypoesthesia. QST may identify patients suitable for intervention.