Inpatient falls after total knee arthroplasty: the role of anesthesia type and peripheral nerve blocks.

BACKGROUND: Much controversy remains on the role of anesthesia technique and peripheral nerve blocks (PNBs) in inpatient falls (IFs) after orthopedic procedures. The aim of the study is to characterize cases of IFs, identify risk factors, and study the role of PNB and anesthesia technique in IF risk in total knee arthroplasty patients. METHODS: The authors selected total knee arthroplasty patients from the national Premier Perspective database (Premier Inc., Charlotte, NC; 2006-2010; n = 191,570, >400 acute care hospitals). The primary outcome was IF. Patient- and healthcare system-related characteristics, anesthesia technique, and presence of PNB were determined for IF and non-IF patients. Independent risk factors for IFs were determined by using conventional and multilevel logistic regression. RESULTS: Overall, IF incidence was 1.6% (n = 3,042). Distribution of anesthesia technique was 10.9% neuraxial, 12.9% combined neuraxial/general, and 76.2% general anesthesia. PNB was used in 12.1%. Patients suffering IFs were older (average age, 68.9 vs. 66.3 yr), had higher comorbidity burden (average Deyo index, 0.77 vs. 0.66), and had more major complications, including 30-day mortality (0.8 vs. 0.1%; all P < 0.001). Use of neuraxial anesthesia (IF incidence, 1.3%; n = 280) had lower adjusted odds of IF compared with adjusted odds of IF with the use of general anesthesia alone (IF incidence, 1.6%; n = 2,393): odds ratio, 0.70 (95% CI, 0.56-0.87). PNB was not significantly associated with IF (odds ratio, 0.85 [CI, 0.71-1.03]). CONCLUSIONS: This study identifies several risk factors for IF in total knee arthroplasty patients. Contrary to common concerns, no association was found between PNB and IF. Further studies should determine the role of anesthesia practices in the context of fall-prevention programs.

Cost of sterility: probe covers should not be mandated for single-shot peripheral nerve blocks.

Ultrasound guidance has become ubiquitous with regional anesthesia, but little consistency exists on necessary ultrasound probe hygiene and sterility barriers. Fear of possible infection has led to calls for universal use of sterile ultrasound probe covers. Available data seems to suggest that single-shot peripheral nerve blocks have a low infectious risk. The widespread use of single-use disposable probe covers would carry an associated cost, increased environmental impact, and little evidence to suggest that they are effective at preventing infection if proper technique is used. While various parties have labeled single-shot nerve blocks as a sterile procedure, in practice, it is a clean technique. In this article, we argue that mandating the use of probe covers is unnecessary and that it should be left to the anesthesiologist to determine what type of anti-infection equipment is necessary for single-shot nerve blocks based on their practice situation and expertize.

Anesthesia start time documentation accuracy where peripheral nerve block is the primary anesthetic.

INTRODUCTION: When used as the primary anesthetic, nerve blocks are not billed as separate procedures. In this scenario, the anesthesia start (AStart) time should include the block procedural time. We measured how often AStart time was documented before the nerve block was placed in the preoperative area, and compared cases where a block team performed the nerve block and cases where the intraoperative anesthesia attending supervised the nerve block. We hypothesized that the involvement of a regional anesthesia team would lead to more accurate documentation of AStart. We also estimated the lost revenue due to inaccurate start time documentation. METHODS: The study population were patients undergoing surgery with a peripheral nerve block as the primary anesthetic. For this analysis, AStart occurring less than 10 min before the in-operating room time was defined as potentially inaccurate. Lost potential revenue was estimated by taking the difference between the documented time of local anesthetic administration and the documented AStart time. RESULTS: A total of 745 cases were analyzed. Overall, 439 cases (58%) cases were identified as having potentially inaccurate start times. There were higher rates of inaccurate AStart documentation by the block team (316/482, 65.5%) compared with blocks supervised by the in-room anesthesia attendings (123/263, 46.7%, p<0.001). Overall, the estimated loss in billable revenue during the study period was a total of $70 265. CONCLUSIONS: The performance of primary regional anesthesia procedure by a block team increased the incidence of inaccurate documentation and uncaptured potential revenue. There is need for education about accurate nerve block documentation for anesthesiologists, especially when separate teams are used.

Outcomes After Orthopedic Trauma Surgery - What is the Role of the Anesthesia Choice?

The body of literature concerning the influence of anesthetic type on many perioperative outcomes has grown considerably in recent years. Most studies have suggested that particularly in orthopedic patients, regional anesthesia may be associated with improved perioperative outcomes. Orthopedic trauma presents itself as a field that might benefit from increased utilization of regional techniques with the goal to improve outcomes. This narrative review concludes that, indeed, regional anesthesia seems to provide benefits for morbidity, pain control, and improved return to function in hip fracture, rib fracture, and isolated extremity fracture patients.

Improving Safety of Bilateral Knee Arthroplasty: Impact of Selection Criteria on Perioperative Outcome.

Background: Bilateral total knee arthroplasty (BTKA) procedures are associated with an increased risk of complications when compared with unilateral approaches. In 2006, in an attempt to reduce this risk, our institution implemented selection criteria that specified younger and healthier patients as candidates for BTKA. Questions/Purpose: We sought to investigate the effect of these selection criteria on perioperative outcomes. Methods: In a retrospective cohort study, we used institutional data to identify patients who underwent BTKA between 1998 and 2014. Patients were divided into 2 groups: those who underwent surgery before the 2006 introduction of our selection criteria (1998-2006) and those who underwent surgery after (2007-2014). Groups were compared in terms of demographics, comorbidity burden, and incidence of perioperative complications. Regression analysis was performed, calculating incidence rate ratios to evaluate changes in complication rates. Results: Before the selection criteria were implemented in 2006, patients who underwent BTKA were older and had a higher comorbidity burden. The rate of major complications per 1000 hospital days decreased from 31.5 in 1998 to 7.9 in 2014. A reduction in cardiac complications was the most significant contributor to this decrease in major complications. Conclusion: After stringent criteria for BTKA candidates were implemented at our institution, selection of younger patients with lower comorbidity burden was accompanied by a reduction in the incidence of operative complications. This suggests that introducing such criteria can be associated with a reduction in adverse perioperative outcomes.

The L-type calcium channel Cav1.3 is required for proper hippocampal neurogenesis and cognitive functions.

L-type voltage gated Ca(2+) channels (LTCCs) are widely expressed within different brain regions including the hippocampus. The isoforms Cav1.2 and Cav1.3 have been shown to be involved in hippocampus-dependent learning and memory, cognitive functions that require proper hippocampal neurogenesis. In vitro, functional LTCCs are expressed on neuronal progenitor cells, where they promote neuronal differentiation. Expression of LTCCs on neural stem and progenitor cells within the neurogenic regions in the adult brain in vivo has not been examined so far, and a contribution of the individual isoforms Cav1.2 and Cav1.3 to adult neurogenesis remained to be clarified. To reveal the role of these channels we first evaluated the expression patterns of Cav1.2 and Cav1.3 in the hippocampal dentate gyrus and the subventricular zone (SVZ) in adult (2- and 3-month old) and middle-aged (15-month old) mice on mRNA and protein levels. We performed immunohistological analysis of hippocampal neurogenesis in adult and middle-aged Cav1.3(-/-) mice and finally addressed the importance of Cav1.3 for hippocampal function by evaluating spatial memory and depression-like behavior in adult Cav1.3(-/-) mice. Our results showed Cav1.2 and Cav1.3 expression at different stages of neuronal differentiation. While Cav1.2 was primarily restricted to mature NeuN(+) granular neurons, Cav1.3 was expressed in Nestin(+) neural stem cells and in mature NeuN(+) granular neurons. Adult and middle-aged Cav1.3(-/-) mice showed severe impairments in dentate gyrus neurogenesis, with significantly smaller dentate gyrus volume, reduced survival of newly generated cells, and reduced neuronal differentiation. Further, Cav1.3(-/-) mice showed impairment in the hippocampus dependent object location memory test, implicating Cav1.3 as an essential element for hippocampus-associated cognitive functions. Thus, modulation of LTCC activities may have a crucial impact on neurogenic responses and cognition, which should be considered for future therapeutic administration of LTCCs modulators.

Moist dressing coverage supports proliferation and migration of transplanted skin micrografts in full-thickness porcine wounds.

Transplantation of skin micrografts in a 1:100 ratio regenerate the epidermis of full-thickness wounds in pigs within 14 days in a wet environment. The aim of the current study was to combine micrografts and commercially available moist dressings. We hypothesized that micrografts regenerate the epidermis when covered with a moist dressing. 5cm×5cm and 10cm×10cm full-thickness wounds were created on the backs of pigs. Wounds were transplanted with 0.8mm×0.8mm micrografts created from a split-thickness skin graft in a 1:100 ratio. 5cm×5cm wounds were treated with wound chambers, moist dressings or dry gauze (non-transplanted control group). 10cm×10cm wounds were compared to non-transplanted wounds, both covered with moist dressings. Reepithelialization was assessed in biopsies from day 10, 14 and 18 post-transplantation. 5cm×5cm transplanted wounds covered with moist dressings showed 69.5±20.6% reepithelialization by day 14 and 90.5±10.4% by day 18, similar to wounds covered with a wound chamber (63.9±16.7 and 86.2±11.9%, respectively). 18 days post-transplantation, 10cm×10cm transplanted wounds covered with moist dressings showed 66.1±10.3% reepithelialization, whereas nontransplanted wounds covered with moist dressings were 40.6±6.6% reepithelialized. We conclude that micrografts combined with clinically available moist dressings regenerate the epidermis of full-thickness wounds.