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Objectives The authors sought to prospectively determine the safety and efficacy of next-day discharge using the Vancouver 3M (Multidisciplinary, Multimodality, but Minimalist) Clinical Pathway. Background Transfemoral transcatheter aortic valve replacement (TAVR) is an alternative to surgery in high- and intermediate-risk patients; however, hospital stays average at least 6 days in most trials. The Vancouver 3M Clinical Pathway is focused on next-day discharge, made possible by the use of objective screening criteria as well as streamlined peri- and post-procedural management guidelines. Methods Patients were enrolled from 6 low-volume ( 200 TAVR/year) centers in Canada and the United States. The primary outcomes were a composite of all-cause death or stroke by 30 days and the proportion of patients successfully discharged home the day following TAVR. Results Of 1,400 screened patients, 411 were enrolled at 13 centers and received a SAPIEN XT (58.2%) or SAPIEN 3 (41.8%) valve (Edwards Lifesciences, Irvine, California). In centers enrolling exclusively in the study, 55% of screened patients were enrolled. The median age was 84 years (interquartile range: 78 to 87 years) with a median STS score of 4.9% (interquartile range: 3.3% to 6.8%). Next-day discharge home was achieved in 80.1% of patients, and within 48 h in 89.5%. The composite of all-cause mortality or stroke by 30 days occurred in 2.9% (95% confidence interval: 1.7% to 5.1%), with neither component of the primary outcome affected by hospital TAVR volume (p = 0.51). Secondary outcomes at 30 days included major vascular complication 2.4% (n = 10), readmission 9.2% (n = 36), cardiac readmission 5.7% (n = 22), new permanent pacemaker 5.7% (n = 23), and >mild paravalvular regurgitation 3.8% (n = 15). Conclusions Adherence to the Vancouver 3M Clinical Pathway at low-, medium-, and high-volume TAVR centers allows next-day discharge home with excellent safety and efficacy outcomes.

Physical inactivity is increasing among children globally and has been directly linked to the growing problems of overweight and obesity. We aim to assess the impact of a new mobile exergame, MobileKids Monster Manor (MKMM), in a school-based setting. MKMM, developed with input from youth to enhance physical activity, is wirelessly connected to an accelerometer-based activity monitor. Forty-two healthy students (11.3 ± 1.2 years old and 0.28 ± 1.29 body-mass index [BMI] z-score) participated in a randomized 4-week crossover study to evaluate the game intervention. The two study arms consisted of week-long baseline, game intervention/control, washout, and control/game intervention phases. All participants were required to wear an activity monitor at all times to record steps and active minutes for the study duration. MKMM was used during each arm's respective intervention week, during which children were asked to play the game at their convenience. When children were exposed to the game, an increase compared with the control phase of 2,934 steps per day (p = 0.0004, 95% CI 1,434-4,434) and 46 active minutes per day (p = 0.001, 95% CI 20-72) from baseline (12,299 steps/day and 190 active minutes/day) was observed. A linear regression model showed that MKMM yielded a greater increase in steps and active minutes per day among children with a higher BMI z-score, showing 10 percent more steps per day and 14 percent more active minutes per day relative to baseline, per unit increase in BMI z-score. In conclusion, MKMM increased steps and active minutes in a school-based environment. This suggests that mobile exergames could be useful tools for schools to promote physical activity and combat obesity in adolescents.

Feasibility of closed-loop anesthesia has been shown in a number of clinical studies. Demonstration of patient safety will be essential to convince regulatory authorities of the benefits of such systems. This paper considers safety constraints for closed-loop propofol anesthesia based on its therapeutic range. Simulation scenarios are proposed for evaluation of control strategies in the presence of these constraints. The scenarios reproduce realistic situations encountered in clinical practice. Using the proposed scenarios, the performance of ℒ 2 anti-windup is compared to sliding mode reference conditioning and to back-calculation anti-windup. It is concluded that ℒ 2 anti-windup might not be appropriate for this problem. The sliding mode solution results in behaviour comparable to the Hanus conditioned controller and there seems to be no need for fast switching. The back-calculation anti-windup performs well in a variety of situations.

There is an urgent need for both the scientific development and clinical validation of novel therapies for acute spinal cord injury (SCI). The scientific development of novel therapies would be facilitated by a better understanding of the acute pathophysiology of human SCI. Clinical validation of such therapies would be facilitated by the availability of biomarkers with which to stratify injury severity and predict neurological recovery. Cerebrospinal fluid (CSF) samples were obtained over a period of 72 h in 27 patients with complete SCI (ASIA A) or incomplete SCI (ASIA B or C). Cytokines were measured in CSF and serum samples using a multiplex cytokine array system and standard enzyme-linked immunosorbent assay (ELISA) techniques. Neurological recovery was monitored, and patient-reported neuropathic pain was documented. IL-6, IL-8, MCP-1, tau, S100beta, and glial fibrillary acidic protein (GFAP) were elevated in a severity-dependent fashion. A biochemical model was established using S100beta, GFAP, and IL-8 to predict injury severity (ASIA A, B, or C). Using these protein concentrations at 24-h post injury, the model accurately predicted the observed ASIA grade in 89% of patients. Furthermore, segmental motor recovery at 6 months post injury was better predicted by these CSF proteins than with the patients' baseline ASIA grade. The pattern of expression over the first 3 to 4 days post injury of a number of inflammatory cytokines such as IL-6, IL-8, and MCP-1 provides invaluable information about the pathophysiology of human SCI. A prediction model that could use such biological data to stratify injury severity and predict neurological outcome may be extremely useful for facilitating the clinical validation of novel treatments in acute human SCI.

Object Ischemia is an important factor in the pathophysiology of secondary damage after traumatic spinal cord injury (SCI) and, in the setting of thoracoabdominal aortic aneurysm repair, can be the primary cause of paralysis. Lowering the intrathecal pressure (ITP) by draining CSF is routinely done in thoracoabdominal aortic aneurysm surgery but has not been evaluated in the setting of acute traumatic SCI. Additionally, while much attention is directed toward maintaining an adequate mean arterial blood pressure (MABP) in the acute postinjury phase, little is known about what is happening to the ITP during this period when spinal cord perfusion pressure (MABP − ITP) is important. The objectives of this study were to: 1) evaluate the safety and feasibility of draining CSF to lower ITP after acute traumatic SCI; 2) evaluate changes in ITP before and after surgical decompression; and 3) measure neurological recovery in relation to the drainage of CSF. Methods Twenty-two patients seen within 48 hours of injury were prospectively randomized to a drainage or no-drainage treatment group. In all cases a lumbar intrathecal catheter was inserted for 72 hours. Acute complications of headache/nausea/vomiting, meningitis, or neurological deterioration were carefully monitored. Acute Spinal Cord Injury motor scores were documented at baseline and at 6 months postinjury. Results On insertion of the catheter, mean ITP was 13.8 ± 1.3 mm Hg (± SD), and it increased to a mean peak of 21.7 ± 1.5 mm Hg intraoperatively. The difference between the starting ITP on catheter insertion and the observed peak intrathecal pressure after decompression was, on average, an increase of 7.9 ± 1.6 mm Hg (p < 0.0001, paired t-test). During the postoperative period, the peak recorded ITP in the patients randomized to the no-drainage group was 30.6 ± 2.3 mm Hg, which was significantly higher than the peak intraoperative ITP (p = 0.0098). During the same period, the peak recorded ITP in patients randomized to receive drainage was 28.1 ± 2.8 mm Hg, which was not statistically higher than the peak intraoperative ITP (p = 0.15). Conclusions The insertion of lumbar intrathecal catheters and the drainage of CSF were not associated with significant adverse events, although the cohort was small and only a limited amount of CSF was drained. Intraoperative decompression of the spinal cord results in an increase in the ITP measured caudal to the injury site. Increases in intrathecal pressure are additionally observed in the postoperative period. These increases in intrathecal pressure result in reduced spinal cord perfusion that will otherwise go undetected when measuring only the MABP. Characteristic changes in the observed intrathecal pressure waveform occur after surgical decompression, reflecting the restoration of CSF flow across the SCI site. As such, the waveform pattern may be used intraoperatively to determine if adequate decompression of the thecal sac has been accomplished.

The majority of children in North America are not meeting current physical activity guidelines. The purpose of this study was to evaluate the impact of a mobile phone game ("MobileKids Monster Manor") as a tool to promote voluntary physical activity among children.The game integrates data from an accelerometer-based activity monitor (Tractivity(®); Kineteks Corp., Vancouver, BC, Canada) wirelessly connected to a phone and was developed with the involvement of a team of young advisors (KidsCan Initiative: Involving Youth as Ambassadors for Research). Fifty-four children 8-13 years old completed a week of baseline data collection by wearing an accelerometer but receiving no feedback about their activity levels. The 54 children were then sequentially assigned to two groups: One group played "MobileKids Monster Manor," and the other received daily activity feedback (steps and active minutes) via an online program. The physical activity (baseline and intervention weeks) was measured using the activity monitor and compared using two-way repeated-measures analysis of variance (intervention×time).Forty-seven children with a body mass index (BMI) z-score of 0.35±1.18 successfully completed the study. Significant (P=0.01) increases in physical activity were observed during the intervention week in both the game and feedback groups (1191 and 796 steps/day, respectively). In the game group, greater physical activity was demonstrated in children with higher BMI z-score, showing 964 steps/day more per BMI z-score unit (P=0.03; 95 percent confidence interval of 98 to 1829).Further investigation is required to confirm that our game design promotes physical activity.

Objectives: The purpose of this study was to assess the validity of using a pulsatile, pressure waveform transduced from the epidural space through an epidural needle or catheter to confirm correct placement for maximal analgesia and to compare 3 different types of catheters’ ability to transduce a waveform. Design: A single-center, prospective, randomized trial. Setting: A tertiary-referral hospital. Participants: Eighty-one patients undergoing posterolateral thoracotomy who required a thoracic epidural catheter for postoperative pain management. Interventions: Each epidural needle and each epidural catheter was transduced to determine if there was a pulsatile waveform exhibited. Measurements and Main Results: Sensitivity of the pulsatile waveform transduced through an epidural needle to identify correct placement of the epidural needle and the sensitivity of each catheter type to identify placement were compared. In 79 of 81 cases (97.5%), the waveform transduced directly through the epidural needle had a pulsatile characteristic as determined by blinded observers. In a total of 53 of 81 epidural catheters (65.4%), the transduced waveform displayed pulsations. Twenty-four of 27 catheters in group S-P/Sims Portex (Smiths Medical MD, Inc, St Paul, MN) (88.9%) transduced a pulsatile tracing from the epidural space, a significantly greater percentage than in the other 2 groups (p = 0.02). Conclusions: The technique of transducing the pressure waveform from the epidural needle inserted in the epidural space is a sensitive and reliable alternative to other techniques for confirmation of correct epidural catheter placement. The technique is simple, sensitive, and inexpensive and uses equipment available in any operating room.

The GlideScope Video Laryngoscope is a new intubating device. It was designed to provide a view of the glottis without alignment of the oral, pharyngeal and tracheal axes. The aim of the study was to describe the use of the GlideScope in comparison with direct laryngoscopy for elective surgical patients requiring tracheal intubation.Two hundred patients were randomly assigned to intubation by direct laryngoscopy using a Macintosh size 3 blade (DL, n=100) or intubation using the GlideScope (GS, n=100). Prior to intubation all patients were given a Cormack and Lehane (CL) grade by a separate anaesthetist using a Macintosh size 3 blade. The patient was then intubated, using direct laryngoscopy or the GlideScope, by a different anaesthetist during which the larynx was inspected and given a laryngoscopy score. Time to intubate was measured.In the GS group, laryngoscopy grade was improved in the majority (28/41) of patients with CL grade1 and in all but one of patients who were grade 3 laryngoscopy (P0.001). The overall mean time to intubate was 30 (95% CI 28-33) s in the DL group and 46 (95% CI 43-49) s in the GS group. The time to intubate for CL grade 3 was similar in both groups, being 47 s for the DL group and 50 s for the GS group respectively.In most patients, the GlideScope provided a laryngoscopic view equal to or better than that of direct laryngoscopy, but it took an additional 16 s (average) for tracheal intubation. It has potential advantages over standard direct laryngoscopy for difficult intubations.

Study Design. A prospective, randomized, double-blind clinical trial was conducted. Objective. To compare the efficacy of patient-conitrolled analgesia (PCA) with that of patient-controlled epidural analgesia (PCEA) in terms of-overall patient satisfaction with postoperative pain -management after lumbar spine fusion. of Background -Data. in numerous surgical disciplines, PCEA and PCA have proved to be effective methods of postoperative pain control. The literature states that with PCEA, less opioid use is required during the immediate postoperative period to maintain equivalent -pain control compared to PCA. Continuous epidurat infusion has been assessed in spine fusion patients, but PCEA has not been evaluated. Furthermore, this- is the first prospective randomized clinical trial to assess overall patient-satisfaction while stratifying patients for both anx iety level and preoperative opioid use. Methods. For this study, 74 patients were assigned randomly to -one of two treatment groups, with PCA and PCEA administered in a double-blind manner for a 3-day postoperative course. All the patients. received both PCA and PCEA delivery systems. Assessment was by a blinded, independent observer. Overall patient satisfaction with pain management was assessed by a visual analog scale at the end of postoperative day 3. Secondary measures included: three scales from the Functional Independence - Measure instrument; opioid quantity; side effects; and length of hospital stay, Results. Thirty-eight patients worn randomized to PCA, and 36 were randomized. to PCEA. No baseline variable differences between the groups were observed. The results showed no difference between the groups on the following measures: overall patient satisfaction with pain management, ambulation, and length of stay. The PCA patients used significantly more opioid than the PCEA patients. Conclusions. Both postoperative analgesic regimens provided good overall patient satisfaction. The only clinical advantage of PCEA over PCA for spine fusion patients was the lower amount of opioid consumed, althouoh the PCEA group experienced significantly more side effects than the PCA group. There were no other significant differences. Therefore, patient or physician preference could select either postoperative pain management delivery system.

N-methyl-D-aspartate (NMDA) antagonists combined with opioids are thought to be effective in the control of pain states. We evaluated morphine use and analgesia in 37 patients postlaparotomy. Patients received 60 mg of oral dextromethorphan or placebo the night before and again 1 h before surgery. Morphine was titrated intraoperatively to maintain blood pressure and heart rate within 20% of baseline and postoperatively via patient-controlled analgesia (PCA). The dextromethorphan and placebo groups were compared for morphine use intraoperatively, in recovery, via PCA in the first 4 and 24 h, and total use over the study period. Pain scores at rest and on activity for the first 4 and 24 h were also compared. Intraoperatively, the dextromethorphan group required less morphine: 13.1 +/- 4.3 vs 17.6 +/- 6.0 mg (P = 0.012). Postoperatively, there was no significant difference between the dextromethorphan and placebo groups for morphine use: in the recovery room 10.9 +/- 7.7 vs 12.1 +/- 7.7 mg; the first 4 h of PCA 15.9 +/- 9.3 vs 12.7 +/- 5.1 mg; the first 24 h of PCA 76.4 +/- 44.7 vs 61.8 +/- 27.5 mg; or in total morphine use 100.4 +/- 49.5 vs 91.5 +/- 33.1 mg. Pain scores for the two groups were not statistically different throughout the study period. We conclude that 60 mg of oral dextromethorphan given the night before and repeated an hour before surgery does not provide a postoperative morphine-sparing effect or improve analgesia after laparotomy. Implications: Patients given dextromethorphan before surgery had significantly reduced intraoperative morphine requirements. However, postoperative morphine requirements were unaltered. Dextromethorphan may need to be continued postoperatively to improve postoperative analgesia. (Anesth Analg 1998;87:1135-8)

This paper describes the design of a robust proportional-integral derivative (PID) controller for propofol infusion in children and presents the results of clinical evaluation of this closed-loop system during endoscopic investigations in children age 6-17. The controller design is based on a set of models that describes the interpatient variability in the response to propofol infusion in the study population. The PID controller is tuned to achieve sufficient robustness margins for the identified uncertainty. 108 children were enrolled in this study, and anesthesia was closed-loop controlled in 102 of these cases. Clinical evaluation of the system shows that closed-loop control of both induction and maintenance of anesthesia in children based on the WAVCNS index as a measure of clinical effect is feasible. A robustly tuned PID controller can accommodate the interpatient variability in children and spontaneous breathing can be maintained in most subjects.

Background During closed-loop control, a drug infusion is continually adjusted according to a measure of clinical effect (e.g., an electroencephalographic depth of hypnosis (DoH) index). Inconsistency in population-derived pediatric pharmacokinetic/pharmacodynamic models and the large interpatient variability observed in children suggest a role for closed-loop control in optimizing the administration of intravenous anesthesia. Objective To clinically evaluate a robustly tuned system for closed-loop control of the induction and maintenance of propofol anesthesia in children undergoing gastrointestinal endoscopy. Methods One hundred and eight children, aged 6-17, ASA I-II, were enrolled. Prior to induction of anesthesia, NeuroSENSE™ sensors were applied to obtain the WAVCNS DoH index. An intravenous cannula was inserted and lidocaine (0.5 mg·kg(-1) ) administered. Remifentanil was administered as a bolus (0.5 μg·kg(-1) ), followed by continuous infusion (0.03 μg·kg(-1) ·min(-1) ). The propofol infusion was closed-loop controlled throughout induction and maintenance of anesthesia, using WAVCNS as feedback. Results Anesthesia was closed-loop controlled in 102 cases. The system achieved and maintained an adequate DoH without manual adjustment in 87/102 (85%) cases. Induction of anesthesia (to WAVCNS ≤ 60) was completed in median 3.8 min (interquartile range (IQR) 3.1-5.0), culminating in a propofol effect-site concentration (Ce ) of median 3.5 μg·ml(-1) (IQR 2.7-4.5). During maintenance of anesthesia, WAVCNS was measured within 10 units of the target for median 89% (IQR 79-96) of the time. Spontaneous breathing required no manual intervention in 91/102 (89%) cases. Conclusions A robust closed-loop system can provide effective propofol administration during induction and maintenance of anesthesia in children. Wide variation in the calculated Ce highlights the limitation of open-loop regimes based on pharmacokinetic/pharmacodynamic models.

Purpose: To present a case of respiratory failure following suboccipital craniectomy for Chiari type I malformation. Clinical Features: A 22-yr-old man presented with a two year history of symptoms and signs suggestive of brainstem compression at the level of the foramen magnum. This was confirmed with magnetic resonance imaging. The procedure of suboccipital craniectomy, upper cervical laminectomy and fourth ventricle exploration was performed. Three hours postoperatively the patient experienced episodes of apnea and subsequently became drowsy. Blood gas analysis revealed hypercapnic respiratory failure. Chest X-ray revealed evidence of pulmonary aspiration. The trachea was re-intubated and the lungs ventilated in intensive care for 72 hr. He was discharged home two weeks postoperatively. Conclusion: Chiari type I malformation is associated with a number of associated anomalies. These patients are at considerable risk of respiratory depression and bulbar dysfunction in the perioperative period. The anesthetic issues are reviewed and discussed.

We hope to have inspired an interest in approaching the pain management issues in this challenging group of patients. Despite significant progress in understanding the pathophysiology of pain, the development of therapeutic options, and the publication and dissemination of guidelines, this progress does not seem to have been adopted into clinical practice. Bonica has stated "for many years I have studied the reasons for inadequate management of postoperative pain, and they remain the same.... Inadequate or improper application of available information and therapies is certainly the most important reason". Let us accept the challenge to re-evaluate pain management in the postoperative neurosurgical patient. Future development may provide enhanced multimodal analgesia with the development of enantioselective NSAIDs and peripherally acting opioids that do not cross the blood-brain barrier. Targeted inhibition of the central neuroplasticity that underlies sensitization, rather than attempts to use pre-emptive analgesics, may be more fruitful. Inhibition of excitatory amino acids may prove beneficial for perioperative neuroprotection and pain management. In addition, longer-acting local anesthetics show significant promise. The importance of understanding the specific benefits available and matching these characteristics to the particular patient is emphasized. Evaluation of outcomes, including morbidity and patient satisfaction, will determine if effective and rational provision of analgesia may indeed be safer than withholding analgesia. However, it is clear that re-evaluation and refinement of conventional therapy is necessary.