Effects of an anesthesia perioperative surgical home for total knee and hip arthroplasty at a Veterans Affairs Hospital: a quality improvement before-and-after cohort study.

BACKGROUND: A perioperative surgical home, the Anesthesia Perioperative Care Service (APCS), was created to execute enhanced recovery after surgery pathways for total knee and total hip arthroplasty patients at the Tennessee Valley Health System Nashville VA Medical Center. We hypothesized that the APCS would be associated with reduced length of stay, in-hospital and post-discharge opioid exposure, costs, and hospital readmissions. METHODS: Data were collected for all patients admitted to the Nashville VA Medical Center following their respective surgery, for 400 days after the initiation of the APCS and for a 400-day period prior. This cohort study was based on a quality improvement project set up at the initiation of the service. The adjusted effect on each quantitative outcome was evaluated using proportional odds logistic regression methods. In addition, each regression analysis was performed in segmented regression fashion to identify changes in the outcomes over time. RESULTS: We included 282 patients in our cohort-96 prior and 186 post-implementation. Median hospital length of stay, intravenous (IV) and per os (PO) inpatient opioid administration, outpatient opioid quantity, and total days of supply were all reduced in the cohort cared for by the APCS. After adjusting for potential cofounders and evaluated outcome over time, the APCS remained independently associated with a reduction of hospital length of stay of one day (95% confidence interval, 0.09 to 1.97; P = 0.05) and with decreased IV and PO inpatient opioid administration, while continuing to show no increase in hospital readmissions. CONCLUSIONS: This cohort study showed significant improvements in important post-surgical outcomes after total knee and hip arthroplasty that were associated with the implementation of an APCS.

RéSUMé: CONTEXTE: Un centre de soins chirurgicaux périopératoires (perioperative surgical home), le Service de soins périopératoires en anesthésie (SSPA), a été créé pour mettre en œuvre des trajectoires de soins de récupération rapide après la chirurgie pour les patients ayant subi une arthroplastie totale du genou ou de la hanche au centre médical Tennessee Valley Health System Nashville VA Medical Center. Nous avons émis l'hypothèse que le SSPA serait associé à une réduction de la durée du séjour, de l'exposition aux opioïdes à l'hôpital et après le congé, ainsi qu'à une diminution des coûts et des réadmissions à l'hôpital. MéTHODE: Les données ont été recueillies pour tous les patients admis au centre médical Nashville VA Medical Center après leur chirurgie respective, pendant 400 jours avant et après la création du SSPA. Cette étude de cohorte se fondait sur un projet d'amélioration de la qualité mis en place lors de l'inauguration du service. L'effet ajusté sur chaque résultat quantitatif a été évalué à l'aide de méthodes de régression logistique proportionnelles. De plus, chaque analyse de régression a été effectuée de façon segmentée afin d'identifier l'évolution des résultats au fil du temps. RéSULTATS: Nous avons inclus 282 patients dans notre cohorte ­ 96 avant et 186 après la mise en œuvre. La durée médiane du séjour à l'hôpital, l'administration d'opioïdes par voie intraveineuse (IV) et per os (PO) pendant le séjour hospitalier, la quantité d'opioïdes en ambulatoire et sa durée en jours ont tous été réduites dans la cohorte prise en charge par le SSPA. Après avoir procédé à des ajustements pour tenir compte des facteurs de confusion potentiels et évalué l'évolution des résultats au fil du temps, le SSPA est demeuré indépendamment associé à une réduction de la durée de séjour à l'hôpital d'un jour (intervalle de confiance 95 %, 0,09 à 1,97; P = 0,05), à une réduction de l'administration d'opioïdes IV et PO durant le séjour, et il n'y a eu aucune augmentation des réadmissions à l'hôpital. CONCLUSION: Cette étude de cohorte a montré des améliorations significatives en matière de résultats post-chirurgicaux importants après une arthroplastie totale du genou et de la hanche associés à la mise en œuvre d'un SSPA.

Non-Invasive Venous waveform Analysis (NIVA) for volume assessment during complex cranial vault reconstruction: A proof-of-concept study in children.

BACKGROUND: Non-Invasive Venous waveform Analysis (NIVA) is novel technology that captures and analyzes changes in venous waveforms from a piezoelectric sensor on the wrist for hemodynamic volume assessment. Complex cranial vault reconstruction is performed in children with craniosynostosis and is associated with extensive blood loss, potential life-threatening risks, and significant morbidity. In this preliminary study, we hypothesized that NIVA will provide a reliable, non-invasive, quantitative assessment of intravascular volume changes in children undergoing complex cranial vault reconstruction. OBJECTIVE: To present proof-of-concept results of a novel technology in the pediatric population. METHODS: The NIVA prototype was placed on each subject's wrist, and venous waveforms were collected intraoperatively. Estimated blood loss and fluid/blood product administration were recorded in real time. Venous waveforms were analyzed into a NIVA value and then correlated, along with mean arterial pressure (MAP), to volume changes. Concordance was quantified to determine if the direction of change in volume was similar to the direction of change in MAP or change in NIVA. RESULTS: Of 18 patients enrolled, 14 had usable venous waveforms, and there was a significant correlation between change in NIVA value and change in volume. Change in MAP did not correlate with change in volume. The concordance between change in MAP and change in volume was less than the concordance between change in NIVA and change in volume. CONCLUSION: NIVA values correlate more closely to intravascular volume changes in pediatric craniofacial patients than MAP. This initial study suggests that NIVA is a potential safe, reliable, non-invasive quantitative method of measuring intravascular volume changes for children undergoing surgery.

Non-Invasive Venous waveform Analysis (NIVA) for monitoring blood loss in human blood donors and validation in a porcine hemorrhage model.

STUDY OBJECTIVE: There is an unmet need for a non-invasive approach to diagnose hemorrhage early, before changes in vital signs occur. Non-Invasive Venous waveform Analysis (NIVA) uses a unique physiological signal (the peripheral venous waveform) to assess intravascular volume. We hypothesized changes in the venous waveform would be observed with blood loss in healthy adult blood donors and characterized hemorrhage using invasive monitoring in a porcine model. DESIGN: Prospective observational study. SETTING: American Red Cross donation center. PATIENTS: 50 human blood donors and 12 non-donating controls; 7 Yorkshire pigs. INTERVENTIONS: A venous waveform capturing prototype (NIVA device) was secured to the volar aspect of the wrist in human subjects. A central venous catheter was used to obtain hemodynamic indices and venous waveforms were obtained using the prototype NIVA device over the saphenous vein during 400 mL of graded hemorrhage in a porcine model. MEASUREMENTS: Venous waveforms were transformed from the time to the frequency domain. The ratiometric power contributions of the cardiac frequencies were used to calculate a NIVA value representative of volume status. MAIN RESULTS: A significant decrease in NIVA value was observed after 500 mL of whole blood donation (p < .05). A ROC curve for the ability of the NIVA to detect 500 mL of blood loss demonstrated an area under the curve (AUC) of 0.94. In the porcine model, change in NIVA value correlated linearly with blood loss and with changes in hemodynamic indices. CONCLUSIONS: This study provides proof-of-concept for a potential application of NIVA in detection of blood loss. NIVA represents a novel physiologic signal for detection of early blood loss that may be useful in early triage and perioperative management.

Normal Saline solutions cause endothelial dysfunction through loss of membrane integrity, ATP release, and inflammatory responses mediated by P2X7R/p38 MAPK/MK2 signaling pathways.

Resuscitation with 0.9% Normal Saline (NS), a non-buffered acidic solution, leads to increased morbidity and mortality in the critically ill. The goal of this study was to determine the molecular mechanisms of endothelial injury after exposure to NS. The hypothesis of this investigation is that exposure of endothelium to NS would lead to loss of cell membrane integrity, resulting in release of ATP, activation of the purinergic receptor (P2X7R), and subsequent activation of stress activated signaling pathways and inflammation. Human saphenous vein endothelial cells (HSVEC) incubated in NS, but not buffered electrolyte solution (Plasma-Lyte, PL), exhibited abnormal morphology and increased release of lactate dehydrogenase (LDH), adenosine triphosphate (ATP), and decreased transendothelial resistance (TEER), suggesting loss of membrane integrity. Incubation of intact rat aorta (RA) or human saphenous vein in NS but not PL led to impaired endothelial-dependent relaxation which was ameliorated by apyrase (hydrolyzes ATP) or SB203580 (p38 MAPK inhibitor). Exposure of HSVEC to NS but not PL led to activation of p38 MAPK and its downstream substrate, MAPKAP kinase 2 (MK2). Treatment of HSVEC with exogenous ATP led to interleukin 1ß (IL-1ß) release and increased vascular cell adhesion molecule (VCAM) expression. Treatment of RA with IL-1ß led to impaired endothelial relaxation. IL-1ß treatment of HSVEC led to increases in p38 MAPK and MK2 phosphorylation, and increased levels of arginase II. Incubation of porcine saphenous vein (PSV) in PL with pH adjusted to 6.0 or less also led to impaired endothelial function, suggesting that the acidic nature of NS is what contributes to endothelial dysfunction. Volume overload resuscitation in a porcine model after hemorrhage with NS, but not PL, led to acidosis and impaired endothelial function. These data suggest that endothelial dysfunction caused by exposure to acidic, non-buffered NS is associated with loss of membrane integrity, release of ATP, and is modulated by P2X7R-mediated inflammatory responses.

Creation and Execution of a Novel Anesthesia Perioperative Care Service at a Veterans Affairs Hospital.

Physician-led perioperative surgical home models are developing as a method for improving the American health care system. These models are novel, team-based approaches that help to provide continuity of care throughout the perioperative period. Another avenue for improving care for surgical patients is the use of enhanced recovery after surgery pathways. These are well-described methods that have shown to improve perioperative outcomes. An established perioperative surgical home model can help implementation, efficiency, and adherence to enhanced recovery after surgery pathways. For these reasons, the Tennessee Valley Healthcare System, Nashville Veterans Affairs Medical Center created an Anesthesiology Perioperative Care Service that provides comprehensive care to surgical patients from their preoperative period through the continuum of their hospital course and postdischarge follow-up. In this brief report, we describe the development, implementation, and preliminary outcomes of the service.

Randomized trial of a novel double lumen nasopharyngeal catheter versus traditional nasal cannula during total intravenous anesthesia for gastrointestinal procedures.

STUDY OBJECTIVE: Patients undergoing general anesthesia routinely experience episodes of hypoxemia. There are multiple causes of procedural oxygen desaturation including upper airway obstruction and central hypoventilation. We hypothesize that oxygen supplementation via nasopharyngeal catheter (NPC) will decrease the number of episodes of hypoxemia as compared to traditional NC oxygen supplementation in patients undergoing general anesthesia provided by an anesthesia provider for gastrointestinal endoscopy procedures. DESIGN: Randomized control trial. SETTING: Endoscopy suite. PATIENTS: Sixty patients undergoing intravenous general anesthesia for endoscopic gastrointestinal procedures that did not require endotracheal intubation were enrolled. INTERVENTIONS: Patients were randomized to receive supplemental oxygen by either a standard nasal cannula or a nasopharyngeal catheter. Initial oxygen flow rate was 4l/min and titrated at the anesthesia provider's discretion. Intravenous anesthetic consisted of a propofol infusion. MEASUREMENTS: Hypoxemia was defined as a pulse oximetry reading of <92%. Secondary outcomes included number of airway assist maneuvers such as jaw lift or other airway interventions. MAIN RESULTS: Of the 60 enrolled patients; three subjects in the NPC group were excluded from further analysis. There was no difference between group in age, ASA classification, Body Mass Index, oropharyngeal classification or total propofol dose. Patients who received nasopharyngeal oxygen supplementation were less likely to experience a clinically significant oxygen desaturation event 3 of 27 (11.0%) versus 12 of 30 subjects (40.0%), p=0.013. Interventions to assists with airway management were required for fewer patients in the NPC group 4 (14.8%) versus the NC group, 17 (56.7%), p=0.001. CONCLUSION: Oxygen supplementation via a nasopharyngeal catheter during intravenous general anesthesia resulted in significantly fewer episodes of hypoxemia and number of airway assist maneuvers. Future studies are needed to assess the utility of NPC in other clinical environments where supplemental oxygen is required in the setting of potential airway obstruction.

Oral Baclofen Withdrawal Resulting in Progressive Weakness and Sedation Requiring Intensive Care Admission.

Baclofen is a common medication used as a muscle relaxant and antispasmodic. Baclofen-withdrawal syndrome has many symptoms such as sedation, somnolence, and weakness but can include psychological symptoms. We present a 62-year-old female whose oral baclofen was not continued at a skilled nursing facility after discharge following inpatient surgery that led to the development of altered mental status and respiratory insufficiency necessitating intensive care unit admission. Abrupt cessation of baclofen, no matter the mode of administration to the patient, can lead to baclofen-withdrawal syndrome.

Enhanced recovery after surgery, perioperative medicine, and the perioperative surgical home: current state and future implications for education and training.

PURPOSE OF REVIEW: The purpose of this review is to summarize the current state of perioperative medicine, including the perioperative surgical home (PSH) and enhanced recovery after surgery pathways (ERAS) as well as the educational implications of these concepts for current and future anesthesiology trainees. RECENT FINDINGS: Although there is significant, ongoing discussion surrounding the structural concept of the PSH, there remains little clinical evidence to support its development. On the other hand, publications surrounding ERAS principles continue to show clinical benefit in reducing length of stay, cost, and perioperative complications for a variety of surgical populations. In this milieu, perioperative medicine is increasingly being recognized as its own specialty in perioperative care that encompasses, but is larger than, ERAS. SUMMARY: There is sufficient evidence to support widespread adoption of ERAS principles, although the specifics of local implementation may vary from site to site. There is significant uncertainty as to what the PSH actually is. However, perioperative medicine is a defined specialty in medicine that overlaps significantly with anesthesiology core training and practice and will be a significant focus in future education, research, and clinical care provided by anesthesiologists.

Randomized controlled trial comparing the McGrath MAC video laryngoscope with the King Vision video laryngoscope in adult patients.

BACKGROUND: This study compares the performance of the McGrath MAC and King Vision laryngoscope systems for endotracheal intubation in adult patients with predicted normal airways when used by experienced laryngoscopists with limited prior video laryngoscopy experience. METHODS: The study is a randomized controlled trial in a general adult operating suite at an academic medical center in the South Eastern United States. Sixty-six adult surgical patients with predicted easy intubation were enrolled and randomized to undergo endotracheal intubation with either the McGrath MAC video laryngoscope or the King Vision video laryngoscope using the channeled blade attachment. The primary outcomes were success on first attempt and time of intubation. The laryngoscopic view, lowest observed oxygen saturation, number of attempts, assist maneuvers, and documented airway trauma events were also recorded. RESULTS: The median time for successful intubation was shorter in the McGrath MAC group compared to the King Vision group (17 vs. 38 seconds; P<0.001). There was a higher first attempt success rate in the McGrath MAC group compared to the King Vision group (100% vs. 89%, P<0.01). Also, more patients in the King Vision group had an oxygen desaturation below 90% compared to the McGrath MAC group (3 vs. 0; P<0.034). There were no significant differences between groups in laryngoscopic view, number of attempts, need for assist maneuvers, or airway trauma. CONCLUSION: The McGrath MAC video laryngoscope allowed for significantly shorter times to endotracheal intubation, higher success rates on first attempt, and fewer desaturations compared to the King Vision video laryngoscope when used by experienced laryngoscopists with limited prior video laryngoscopy experience.