Testing of a predictive risk index for persistent postsurgical pain on patients undergoing total knee arthroplasty: A prospective cohort study.

BACKGROUND: We investigated whether a universal predictive risk index for persistent postsurgical pain (PPP) is applicable to patients who undergo total knee arthroplasty (TKA). METHODS: In this cohort study, 392 participants of a randomized study investigating the effects of anaesthesia methods and tourniquet use on TKA were divided into low-, moderate-, and high-risk groups for PPP, as suggested in the previous risk index study. Patients reported pain using the Oxford Knee Score pain subscale and Brief Pain Inventory-short form preoperatively and 3 and 12 months postoperatively. We compared the pain scores of the low- to moderate- and high-risk groups at respective time points and investigated changes in pain scores and the prevalence of PPP at 3 and 12 months after surgery. RESULTS: The high-risk group reported more pain 3 and 12 months after TKA than the low- to moderate-risk group. However, of seven variables, only a single difference reached the threshold for minimal clinical importance between the groups at 12 months. Additionally, at 12 months, the low- to moderate-risk group reported slightly worse improvements in three of seven pain variables than the high-risk group. Depending on the definition, the prevalence of PPP ranged from 2% to 29% in the low- to moderate-risk group and 4% to 41% in the high-risk group 12 months postoperatively. CONCLUSIONS: Although the investigated risk index might predict clinically important differences in PPP between the risk groups at 3 months after TKA, it seems poorly applicable for predicting PPP at 12 months after TKA. SIGNIFICANCE: Although many risk factors for persistent postsurgical pain after total knee arthroplasty have been identified, predicting the risk of this pain has remained a challenge. Results of the current study suggest that accumulation of previously presented modifiable risk factors might be associated with increased postsurgical pain at 3 months, but not at 12 months after total knee arthroplasty.

Systematized Nomenclature of Medicine-Clinical Terminology (SNOMED CT) Clinical Use Cases in the Context of Electronic Health Record Systems: Systematic Literature Review.

BACKGROUND: The Systematized Medical Nomenclature for Medicine-Clinical Terminology (SNOMED CT) is a clinical terminology system that provides a standardized and scientifically validated way of representing clinical information captured by clinicians. It can be integrated into electronic health records (EHRs) to increase the possibilities for effective data use and ensure a better quality of documentation that supports continuity of care, thus enabling better quality in the care process. Even though SNOMED CT consists of extensively studied clinical terminology, previous research has repeatedly documented a lack of scientific evidence for SNOMED CT in the form of reported clinical use cases in electronic health record systems. OBJECTIVE: The aim of this study was to explore evidence in previous literature reviews of clinical use cases of SNOMED CT integrated into EHR systems or other clinical applications during the last 5 years of continued development. The study sought to identify the main clinical use purposes, use phases, and key clinical benefits documented in SNOMED CT use cases. METHODS: The Cochrane review protocol was applied for the study design. The application of the protocol was modified step-by-step to fit the research problem by first defining the search strategy, identifying the articles for the review by isolating the exclusion and inclusion criteria for assessing the search results, and lastly, evaluating and summarizing the review results. RESULTS: In total, 17 research articles illustrating SNOMED CT clinical use cases were reviewed. The use purpose of SNOMED CT was documented in all the articles, with the terminology as a standard in EHR being the most common (8/17). The clinical use phase was documented in all the articles. The most common category of use phases was SNOMED CT in development (6/17). Core benefits achieved by applying SNOMED CT in a clinical context were identified by the researchers. These were related to terminology use outcomes, that is, to data quality in general or to enabling a consistent way of indexing, storing, retrieving, and aggregating clinical data (8/17). Additional benefits were linked to the productivity of coding or to advances in the quality and continuity of care. CONCLUSIONS: While the SNOMED CT use categories were well supported by previous research, this review demonstrates that further systematic research on clinical use cases is needed to promote the scalability of the review results. To achieve the best out-of-use case reports, more emphasis is suggested on describing the contextual factors, such as the electronic health care system and the use of previous frameworks to enable comparability of results. A lesson to be drawn from our study is that SNOMED CT is essential for structuring clinical data; however, research is needed to gather more evidence of how SNOMED CT benefits clinical care and patient safety.

Fat tissue is a poor predictor of 1 year outcomes after total knee arthroplasty: A secondary analysis of a randomized clinical trial.

BACKGROUND AND OBJECTIVE: Obesity may increase the risk of adverse events after total knee arthroplasty (TKA). Although body mass index (BMI) is commonly used in categorizing obesity, its accuracy is limited. Body fat percentage (BFP) might indicate adiposity status and predict arthroplasty-related outcomes better than BMI. We investigated whether BFP is predictive of TKA-related outcomes. METHODS: In this secondary analysis, BFP was measured preoperatively from 294 participants of a randomized trial that investigated the effects of tourniquet and anesthesia methods on TKA. Data concerning in-hospital assessments and events were collected. Knee range of motion (ROM) was measured, the Brief Pain Inventory-short form and Oxford Knee Score questionnaires were used to collect data on patient-reported pain and function, and the 15-dimensional health-related questionnaire was used to assess quality of life preoperatively and 3 and 12 months postoperatively. The patients reported satisfaction to TKA 3 and 12 months postoperatively. Data concerning infectious and thromboembolic events within 90 postoperative days and revision surgery, manipulation under anesthesia, and mortality within 1 year were collected. A separate post hoc analysis was performed for 399 participants to assess the effects of BMI on the respective outcomes. RESULTS: A 1-unit increase in BFP affected the ROM by -0.37° (95% confidence interval (CI) = -0.60 to -0.13) 12 months after surgery. BFP was not significantly associated with the operation time or adverse events. However, the number of most adverse events remained too low for adjusted analysis. A 1-unit increase in BMI increased the operation time by 0.57 min (95% CI = 0.10 to 1.04) and affected the ROM by -0.47° (95% CI = -0.74 to -0.20) 12 months postoperatively. Neither BFP nor BMI was significantly associated with acute pain, pain management, length of stay, or with pain, function, quality of life, or satisfaction to TKA at 12 months after surgery. CONCLUSIONS: BFP seems to be a poor predictor of in-hospital results and of patient-reported outcomes 1 year after TKA. TWITTER HANDLE: In this secondary analysis of a randomized trial, body fat percentage was poorly predictive of clinical outcomes during hospital stay and of patient-reported outcomes 1 year after TKA.

Novel insights on association and reactivity of Bispectral Index, frontal electromyogram, and autonomic responses in nociception-sedation monitoring of critical care patients.

BACKGROUND: Assessing nociception and sedation in mechanically ventilated patients in the ICU is challenging, with few reliable methods available for continuous monitoring. Measurable cardiovascular and neurophysiological signals, such as frontal EEG, frontal EMG, heart rate, and blood pressure, have potential in sedation and nociception monitoring. The hypothesis of this explorative study is that derived variables from the aforementioned signals predict the level of sedation, as described by the Richmond Agitation-Sedation score (RASS), and respond to painful stimuli during critical care. METHODS: Thirty adult postoperative ICU patients on mechanical ventilation and receiving intravenous sedation, excluding patients with primary neurological disorders, head injury, or need for continuous neuromuscular blockage. Bispectral Index (BIS), EMG power (EMG), EMG-derived Responsiveness Index (RI), and averaged blood pressure variability (ARV) were tested against RASS measurements. The aforementioned variables together with blood pressure and Surgical Pleth Index (SPI) were explored before and after painful stimuli (for example bronchoscopy, or pleural puncture) at varying RASS levels, to test variable responsiveness. RESULTS: BIS, EMG, and RI predicted RASS levels with a prediction probability (PK) of 0.776 for BIS, 0.761 for EMG, and 0.763 for RI. In addition, BIS, EMG, and ARV demonstrated responsiveness to painful stimuli during deep sedation (RASS score ≤ -3). CONCLUSION: Variables derived from EEG and EMG are associated with sedation levels, as described by the RASS score. Furthermore, these variables, along with ARV, react with consistency to painful stimuli during deep sedation (RASS -5 to -3), offering novel tools for nociception-sedation monitoring of mechanically ventilated ICU patients requiring deep sedation.

Postoperative pain as a risk factor for stiff knee following total knee arthroplasty and excellent patientreported outcomes after manipulation under anesthesia.

BACKGROUND AND PURPOSE: Manipulation under anesthesia (MUA) is the first-choice treatment for stiffness following total knee arthroplasty (TKA) unresponsive to pain management and physiotherapy. Some of the predisposing factors and patient-reported outcome measures (PROMs) following MUA remain poorly studied. We retrospectively investigated the etiological risk factors and the outcomes of MUA. PATIENTS AND METHODS: 391 TKA patients from a randomized trial comparing the use of a tourniquet and anesthesia (spinal or general) were analyzed, and patients needing MUA were identified (MUA group). We evaluated in-hospital opioid consumption, Oxford Knee Score (OKS), range of motion (ROM), and pain assessed by the Brief Pain Inventory-short form with a 1-year follow-up. RESULTS: 39 (10%) MUA patients were identified. The MUA patients were younger (60 years vs. 64 years, difference -4, 95% CI -6 to -1) and had higher postoperative oxycodone consumption (66 mg vs. 51 mg, median difference 11, CI 1-22) than the no-MUA patients. The proportion of MUA patients who contacted the emergency department within 3 months because of pain was larger than that of non-MUA patients (41% vs. 12%, OR 5, CI 3-10). At the 1-year follow-up, the ROM was improved by 39° following MUA, but the total ROM was worse in the MUA group (115° vs. 124°, p < 0.001). No difference was found in the OKS between the MUA and no-MUA patients. INTERPRETATION: Higher postoperative pain seems to predict MUA risk. MUA performed 3 months postoperatively offers substantial ROM improvement and comparable PROMs to no-MUA patients 1 year after TKA.

Preliminary Exploration of Main Elements for Systematic Classification Development: Case Study of Patient Safety Incidents.

BACKGROUND: Currently, there is no holistic theoretical approach available for guiding classification development. On the basis of our recent classification development research in the area of patient safety in health information technology, this focus area would benefit from a more systematic approach. Although some valuable theoretical and methodological approaches have been presented, classification development literature typically is limited to methodological development in a specific domain or is practically oriented. OBJECTIVE: The main purposes of this study are to fill the methodological gap in classification development research by exploring possible elements of systematic development based on previous literature and to promote sustainable and well-grounded classification outcomes by identifying a set of recommended elements. Specifically, the aim is to answer the following question: what are the main elements for systematic classification development based on research evidence and our use case? METHODS: This study applied a qualitative research approach. On the basis of previous literature, preliminary elements for classification development were specified, as follows: defining a concept model, documenting the development process, incorporating multidisciplinary expertise, validating results, and maintaining the classification. The elements were compiled as guiding principles for the research process and tested in the case of patient safety incidents (n=501). RESULTS: The results illustrate classification development based on the chosen elements, with 4 examples of technology-induced errors. Examples from the use case regard usability, system downtime, clinical workflow, and medication section problems. The study results confirm and thus suggest that a more comprehensive and theory-based systematic approach promotes well-grounded classification work by enhancing transparency and possibilities for assessing the development process. CONCLUSIONS: We recommend further testing the preliminary main elements presented in this study. The research presented herein could serve as a basis for future work. Our recently developed classification and the use case presented here serve as examples. Data retrieved from, for example, other type of electronic health records and use contexts could refine and validate the suggested methodological approach.

Classification of Electronic Health Record-Related Patient Safety Incidents: Development and Validation Study.

BACKGROUND: It is assumed that the implementation of health information technology introduces new vulnerabilities within a complex sociotechnical health care system, but no international consensus exists on a standardized format for enhancing the collection, analysis, and interpretation of technology-induced errors. OBJECTIVE: This study aims to develop a classification for patient safety incident reporting associated with the use of mature electronic health records (EHRs). It also aims to validate the classification by using a data set of incidents during a 6-month period immediately after the implementation of a new EHR system. METHODS: The starting point of the classification development was the Finnish Technology-Induced Error Risk Assessment Scale tool, based on research on commonly recognized error types. A multiprofessional research team used iterative tests on consensus building to develop a classification system. The final classification, with preliminary descriptions of classes, was validated by applying it to analyze EHR-related error incidents (n=428) during the implementation phase of a new EHR system and also to evaluate this classification's characteristics and applicability for reporting incidents. Interrater agreement was applied. RESULTS: The number of EHR-related patient safety incidents during the implementation period (n=501) was five-fold when compared with the preimplementation period (n=82). The literature identified new error types that were added to the emerging classification. Error types were adapted iteratively after several test rounds to develop a classification for reporting patient safety incidents in the clinical use of a high-maturity EHR system. Of the 427 classified patient safety incidents, interface problems accounted for 96 (22.5%) incident reports, usability problems for 73 (17.1%), documentation problems for 60 (14.1%), and clinical workflow problems for 33 (7.7%). Altogether, 20.8% (89/427) of reports were related to medication section problems, and downtime problems were rare (n=8). During the classification work, 14.8% (74/501) of reports of the original sample were rejected because of insufficient information, even though the reports were deemed to be related to EHRs. The interrater agreement during the blinded review was 97.7%. CONCLUSIONS: This study presents a new classification for EHR-related patient safety incidents applicable to mature EHRs. The number of EHR-related patient safety incidents during the implementation period may reflect patient safety challenges during the implementation of a new type of high-maturity EHR system. The results indicate that the types of errors previously identified in the literature change with the EHR development cycle.

Anesthesia Method, Tourniquet Use, and Persistent Postsurgical Pain after Total Knee Arthroplasty: A Prespecified Secondary Analysis of a Randomized Trial.

BACKGROUND: Persistent postsurgical pain after total knee arthroplasty is a common problem and a major reason for patient dissatisfaction. This secondary analysis aimed to investigate the effects of anesthesia (spinal vs. general) and tourniquet use on persistent pain after total knee arthroplasty. METHODS: In this secondary analysis of a previously presented parallel, single-center, randomized trial, 404 patients scheduled for total knee arthroplasty were randomized to spinal versus general anesthesia and no-tourniquet versus tourniquet groups. Patients assessed pain using the Brief Pain Inventory-short form preoperatively and 3 and 12 months postoperatively. The prespecified main outcome was the change in "average pain" measured with numerical 0 to 10 rating scale 1 yr postoperatively. The threshold for clinical importance between groups was set to 1.0. RESULTS: The change in average pain scores 1 yr postoperatively did not differ between the spinal and general anesthesia groups (-2.6 [SD 2.5] vs. -2.3 [SD 2.5], respectively; mean difference, -0.4; 95% CI, -0.9 to 0.1; P = 0.150). The no-tourniquet group reported a smaller decrease in the average pain scores than the tourniquet group (-2.1 [SD 2.7] vs. -2.8 [SD 2.3]; mean difference, 0.6; 95% CI, 0.1 to 1.1; P = 0.012). After 1 yr, the scores concerning the mean of four pain severity variables (numerical rating scale) decreased more in the spinal than in the general anesthesia group (-2.3 [SD 2.2] vs. -1.8 [SD 2.1]; mean difference, -0.5; 95% CI, -0.9 to -0.05; P = 0.029) and less in the no-tourniquet than in the tourniquet group (-1.7 [SD 2.3] vs. -2.3 [SD 2.0]; mean difference, 0.6; 95% CI, 0.2 to 1.0; P = 0.005). None of the differences in pain scores reached the threshold for clinical importance. CONCLUSIONS: The type of anesthesia (spinal vs. general) or tourniquet use has no clinically important effect on persistent postsurgical pain after total knee arthroplasty.

Use of a Tourniquet and Spinal Anesthesia Increases Satisfactory Outcomes After Total Knee Arthroplasty: A Randomized Study.

BACKGROUND: Total knee arthroplasty (TKA) is usually performed successfully with or without a tourniquet and under spinal anesthesia (SA) or general anesthesia (GA). However, 10% to 34% of patients experience dissatisfaction and pain after TKA. We aimed to compare the effects of tourniquet use and SA or GA on TKA outcomes. METHODS: We randomly assigned 404 patients to 4 study groups: SA without a tourniquet (NT/SA), SA with a tourniquet (T/SA), GA without a tourniquet (NT/GA), and GA with a tourniquet (T/GA). The primary outcome was the change in the Oxford Knee Score (OKS) at 1 year postoperatively. Secondary outcomes included a satisfactory TKA outcome assessed using the OKS minimal important change (MIC) and OKS patient acceptable symptom state (PASS), adverse events, and quality of life using the 15-dimensional health-related quality of life tool. RESULTS: At 1 year, the OKS was obtained for 381 patients. In the 2-group comparisons, the tourniquet did not affect the OKS improvement. The SA group had more substantial improvement in the OKS than the GA group (16.21 compared with 14.08 a mean difference of 2.13; 95% confidence interval [CI], 0.55 to 3.71; p = 0.008). In the 4-group comparisons, the T/SA group had more substantial improvements in the OKS than the NT/GA group (16.87 compared with 13.65, a mean difference of 3.2; 95% CI, 0.28 to 6.17; p = 0.026). The SA group reached the OKS MIC more frequently than the GA group (91.7% compared with 81.7%; odds ratio [OR] = 2.49 [95% CI, 1.32 to 4.69]; p = 0.005). The SA group also reached the OKS PASS more frequently than the GA group (86.0% compared with 75.7%; OR = 2.00 [95% CI, 1.18 to 3.39]; p = 0.010). The T/SA group had significantly more patients reaching the OKS MIC than the NT/GA group (95.7% compared with 79.6%; p = 0.005) and more patients reaching the OKS PASS than the NT/GA group (92.6% compared with 74.5%; p = 0.004). No differences were seen with respect to adverse events in any comparisons. CONCLUSIONS: The tourniquet had no detrimental effects on the outcomes of TKA. SA had a positive effect on the OKS. The use of SA combined with a tourniquet resulted in the best improvement in OKS and the highest proportion of satisfactory outcomes with TKA. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Harmonization of Finnish Vaccination Data.

Vaccination information is needed at individual and at population levels, as it is an important part of public health measures. In Finland, a vaccination data structure has been developed for centralized information services that include patient access to information. Harmonization of data with national vaccination registry is ongoing. New requirements for vaccination certificates have emerged because of COVID-19 pandemic. We explore, what is the readiness of Finnish development of vaccination data structures and what can be learned from Finnish harmonization efforts in order to accomplish required level of interoperability.

The European Cross-Border Health Data Exchange: Focus on Clinically Relevant Data.

The eHealth Digital Service Infrastructure (eHDSI) is an infrastructure ensuring the continuity of care for European citizens while they are travelling abroad in the EU. We present the Finnish readiness of implementing datasets of diagnosis, vaccinations and medication summary in a case study, and discuss challenges emerging from the national perspective. International harmonized standards are a key element in the smooth development of European information exchange.

Intravenous patient-controlled analgesia vs nurse administered oral oxycodone after total knee arthroplasty: a retrospective cohort study.

OBJECTIVES: Severe post-operative pain is common after total knee arthroplasty. Patient-controlled analgesia is an alternative method of pain management, whereby a patient administers his or her own pain medication. Patients seem to prefer this method over nurse-administered analgesia. However, it remains unclear whether patients using patient-controlled analgesia devices use higher or lower doses of opioids compared to patients treated with oral opioids. METHODS: This retrospective study examined 164 patients undergoing total knee arthroplasty. Post-operatively, 82 patients received oxycodone via intravenous patient-controlled analgesia devices, while the pain medication for 82 patients in the control group was administered by nurses. The main outcome measure was the consumption of intravenous opioid equivalents within 24 h after surgery. Secondary outcome measures were the use of anti-emetic drugs and the length of stay. Furthermore, we evaluated opioid-related adverse event reports. RESULTS: The consumption of opioids during the first 24 h after surgery and the use of anti-emetic drugs were similar in both groups. The median opioid dose of intravenous morphine equivalents was 41.1 mg (interquartile range (IQR): 29.5-69.1 mg) in the patient-controlled analgesia group and 40.5 mg (IQR: 32.4-48.6 mg) in the control group, respectively. The median length of stay was 2 days (IQR: 2-3 days) in the patient-controlled analgesia group and 3 days (IQR: 2-3 days) in the control group (p=0.02). The use of anti-emetic drugs was similar in both groups. CONCLUSIONS: The administration of oxycodone via intravenous patient-controlled analgesia devices does not lead to increased opioid or anti-emetic consumptions compared to nurse-administered pain medication after total knee arthroplasty. Patient-controlled analgesia might lead to shortened length of stay.

Electronic Health Record System-Related Patient Safety Incidents - How to Classify Them?

The implementation of electronic health record systems (EHRs) may cause multidimensional patient safety issues that deserve research attention. Our research aims to identify the current body of evidence on EHRs-related incident types and how incidents are classified in these studies. A literature search resulted in 44 peer-reviewed papers and six papers were included in the final analysis. The error types do not concern solely the technological features of the EHRs but may involve also non-technical aspects. Our review indicates that standard classification systems would facilitate comparisons across countries. To achieve the goal, more research evidence, testing and development of classifications are required.

Dramatic increase in serum trypsinogens, SPINK1 and hCGß in aortic surgery patients after hypothermic circulatory arrest.

The concentrations of several diagnostic markers have been found to increase dramatically in critically ill patients with a severe disturbance of normal physiological homeostasis, without indication of the diseases they are normally associated with. To prevent false diagnoses and inappropriate treatments of critically ill patients, it is important that the markers aiding the selection of second-line treatments are evaluated in such patients and not only in the healthy population and patients with diseases the markers are associated with. The levels of trypsinogen isoenzymes, the trypsin inhibitor serine peptidase inhibitor Kazal type 1 (SPINK1), hCG and hCGß, which are used as pancreatitis and cancer markers, were analyzed by immunoassays from serum samples of 17 adult patients who have undergone surgery of the ascending aorta during hypothermic circulatory arrest (HCA) with optional selective cerebral perfusion. Highly elevated levels of trypsinogen-1, -2 and -3, SPINK1 and hCGß were observed in patients after HCA. This was accompanied by increased concentrations of S100ß and NSE. In conclusion, this study highlights the importance of critically evaluating the markers used for aiding selection of second line of treatments in critically ill patients.

Effects of anaesthesia method and tourniquet use on recovery following total knee arthroplasty: a randomised controlled study.

BACKGROUND: We investigated the effects of spinal and general anaesthesia and surgical tourniquet on acute pain and early recovery after total knee arthroplasty (TKA). METHODS: Patients (n=413) were randomised to four parallel groups: spinal anaesthesia with or without tourniquet, and general anaesthesia with or without tourniquet. The primary outcome was patient-controlled i.v. oxycodone consumption over 24 postoperative hours. RESULTS: Results from 395 subjects were analysed. Median i.v. oxycodone consumption did not differ between the four groups (spinal anaesthesia without [36.6 mg] and with tourniquet [38.0 mg], general anaesthesia without [42.3 mg] and with tourniquet [42.5 mg], P=0.42), between spinal (37.7 mg) and general anaesthesia (42.5 mg) groups (median difference -3.1, 95% confidence interval [CI] -7.4 to 1.2, P=0.15) and between tourniquet and no-tourniquet groups (40.0 vs 40.0 mg, median difference -0.8, CI -5.1 to 3.5, P=0.72). Vomiting incidence was higher with spinal than with general anaesthesia (21% [42/200] vs 13% [25/194], CI 1.05 to 3.1, P=0.034). The mean haemoglobin decrease was greater without than with tourniquet (-3.0 vs -2.5 g dl-1, mean difference -0.48, CI -0.65 to -0.32, P<0.001). No differences were observed in pain, pain management, incidences of blood transfusions, in-hospital complications, or length of hospital stay. CONCLUSIONS: For TKA, spinal and general anaesthesia with or without tourniquet did not differ in 24-h postoperative opioid consumption, pain management, blood transfusions, in-hospital complications, and length of hospital stay. Vomiting incidence was higher in the spinal than in the general anaesthesia group. Tourniquet use caused smaller decreases in haemoglobin levels. CLINICAL TRIAL REGISTRATION: EudraCT 2016-002035-15.

Randomised controlled study comparing general and spinal anaesthesia with and without a tourniquet on the outcomes of total knee arthroplasty: study protocol.

INTRODUCTION: Total knee arthroplasty is a highly effective treatment for end-stage knee osteoarthritis, and it is usually performed under spinal or general anaesthesia with or without a surgical tourniquet. Some debate about the preferred mode of anaesthesia regarding patient outcomes remains. The aim of this study, which compares general and spinal anaesthesia with and without a tourniquet on the outcomes of total knee arthroplasty, is to determine the optimal type of anaesthesia regimen and assess the effect of a tourniquet on the patient's recovery following total knee arthroplasty. METHODS AND ANALYSIS: This study is a randomised, controlled, parallel-group, four-arm study comparing spinal and general anaesthesia with and without a tourniquet in 400 patients undergoing fast-track total knee arthroplasty, with a 12-month follow-up. The primary outcome is cumulative intravenous oxycodone consumption by patient-controlled analgesia during the first 24 postoperative hours. Secondary outcomes include postoperative nausea and vomiting, the length of hospital stay, the duration of the surgery, blood loss, demand for surgical unit resources, complications, readmissions, postoperative knee function, range of motion, health-related quality of life, prolonged pain and mortality. ETHICS AND DISSEMINATION: This study's protocol is in accordance with the declaration of Helsinki. The results of this study will be disseminated in international peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT03364088; Pre-results.

Algorithm for Quantifying Frontal EMG Responsiveness for Sedation Monitoring.

INTRODUCTION: To study stimulation-related facial electromyographic (FEMG) activity in intensive care unit (ICU) patients, develop an algorithm for quantifying the FEMG activity, and to optimize the algorithm for monitoring the sedation state of ICU patients. METHODS: First, the characteristics of FEMG response patterns related to vocal stimulation of 17 ICU patients were studied. Second, we collected continuous FEMG data from 30 ICU patients. Based on these data, we developed the Responsiveness Index (RI) algorithm that quantifies FEMG responses. Third, we compared the RI values with clinical sedation level assessments and adjusted algorithm parameters for best performance. RESULTS: In patients who produced a clinically observed response to the vocal stimulus, the poststimulus FEMG power was 0.33 µV higher than the prestimulus power. In nonresponding patients, there was no difference. The sensitivity and specificity of the developed RI for detecting deep sedation in the subgroup with low probability of encephalopathy were 0.90 and 0.79, respectively. CONCLUSION: Consistent FEMG patterns were found related to standard stimulation of ICU patients. A simple and robust algorithm was developed and good correlation with clinical sedation scores achieved in the development data.

Frontal electroencephalogram variables are associated with the outcome and stage of hepatic encephalopathy in acute liver failure.

Acute liver failure (ALF) and hepatic encephalopathy (HE) can lead to an elevated intracranial pressure (ICP) and death within days. The impaired liver function increases the risks of invasive ICP monitoring, whereas noninvasive methods remain inadequate. The purpose of our study was to explore reliable noninvasive methods of neuromonitoring for patients with ALF in the intensive care unit (ICU) setting; more specifically, we wanted to track changes in HE and predict the outcomes of ALF patients treated with albumin dialysis. The study included 20 patients with severe ALF at admission who had been referred to the ICU of the liver transplantation (LT) center for albumin dialysis treatment and evaluation for transplantation. Data were collected from all study patients in the form of continuous frontal electroencephalography (EEG) recordings and transcranial Doppler (TCD) measurements of cerebral blood flow. Among the studied EEG variables, the 50% spectral edge frequency decreased and the delta power increased as the HE stage increased. Both variables were predictive of the stage of HE [prediction probability (PK) of 50% spectral edge frequency = 0.23, standard error (SE) = 0.03; PK of delta power = 0.76, SE = 0.03]. The total wavelet subband entropy, a novel variable that we used for tracking abnormal EEG activity, predicted the outcome of ALF patients treated with albumin dialysis (PK = 0.88, SE = 0.09). With a threshold value of 1.6, the TCD pulsatility index had an odds ratio of 1.1 (95% confidence interval = 0.1-9.3) for a poor outcome (LT or death). In conclusion, EEG variables are useful for the monitoring of HE and can be used to predict outcomes of ALF. TCD measurements do not predict patient outcomes.

Hypothermia-treated cardiac arrest patients with good neurological outcome differ early in quantitative variables of EEG suppression and epileptiform activity.

OBJECTIVE: To evaluate electroencephalogram-derived quantitative variables after out-of-hospital cardiac arrest. DESIGN: Prospective study. SETTING: University hospital intensive care unit. PATIENTS: Thirty comatose adult patients resuscitated from a witnessed out-of-hospital ventricular fibrillation cardiac arrest and treated with induced hypothermia (33 degrees C) for 24 hrs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Electroencephalography was registered from the arrival at the intensive care unit until the patient was extubated or transferred to the ward, or 5 days had elapsed from cardiac arrest. Burst-suppression ratio, response entropy, state entropy, and wavelet subband entropy were derived. Serum neuron-specific enolase and protein 100B were measured. The Pulsatility Index of Transcranial Doppler Ultrasonography was used to estimate cerebral blood flow velocity. The Glasgow-Pittsburgh Cerebral Performance Categories was used to assess the neurologic outcome during 6 mos after cardiac arrest. Twenty patients had Cerebral Performance Categories of 1 to 2, one patient had a Cerebral Performance Categories of 3, and nine patients had died (Cerebral Performance Categories of 5). Burst-suppression ratio, response entropy, and state entropy already differed between good (Cerebral Performance Categories 1-2) and poor (Cerebral Performance Categories 3-5) outcome groups (p = .011, p = .011, p = .008) during the first 24 hrs after cardiac arrest. Wavelet subband entropy was higher in the good outcome group between 24 and 48 hrs after cardiac arrest (p = .050). All patients with status epilepticus died, and their wavelet subband entropy values were lower (p = .022). Protein 100B was lower in the good outcome group on arrival at ICU (p = .010). After hypothermia treatment, neuron-specific enolase and protein 100B values were lower (p = .002 for both) in the good outcome group. The Pulsatility Index was also lower in the good outcome group (p = .004). CONCLUSIONS: Quantitative electroencephalographic variables may be used to differentiate patients with good neurologic outcomes from those with poor outcomes after out-of-hospital cardiac arrest. The predictive values need to be determined in a larger, separate group of patients.

Long-term survival after postpartum liver rupture and necrosis requiring liver transplantation in a twin pregnancy.

A 32-year-old G6P5 (hepatitis B carrier, of African origin) with a spontaneous twin pregnancy gave birth at the 37th gestational week. Four hours later she collapsed. Upon an emergency laparotomy, right liver lobe rupture and later massive liver necrosis were diagnosed. Four days later, a liver transplantation was performed. She was discharged from the hospital 38 days after her delivery, four laparotomies, and having received 179 units of red blood cells, 221 units of fresh frozen plasma, 144 units of platelets, and various separate clotting concentrates. As a result of immune suppression medication, she later developed diabetes, sarcoma Kaposi, a Pneumocystis carinii pneumonia, and coenurosis. Four years later, she is, however, in a relatively good condition.