Iron Chelation in Soil: Scalable Biotechnology for Accelerating Carbon Dioxide Removal by Enhanced Rock Weathering.

Enhanced rock weathering (EW) is an emerging atmospheric carbon dioxide removal (CDR) strategy being scaled up by the commercial sector. Here, we combine multiomics analyses of belowground microbiomes, laboratory-based dissolution studies, and incubation investigations of soils from field EW trials to build the case for manipulating iron chelators in soil to increase EW efficiency and lower costs. Microbial siderophores are high-affinity, highly selective iron (Fe) chelators that enhance the uptake of Fe from soil minerals into cells. Applying RNA-seq metatranscriptomics and shotgun metagenomics to soils and basalt grains from EW field trials revealed that microbial communities on basalt grains significantly upregulate siderophore biosynthesis gene expression relative to microbiomes of the surrounding soil. Separate in vitro laboratory incubation studies showed that micromolar solutions of siderophores and high-affinity synthetic chelator (ethylenediamine-N,N'-bis-2-hydroxyphenylacetic acid, EDDHA) accelerate EW to increase CDR rates. Building on these findings, we develop a potential biotechnology pathway for accelerating EW using the synthetic Fe-chelator EDDHA that is commonly used in agronomy to alleviate the Fe deficiency in high pH soils. Incubation of EW field trial soils with potassium-EDDHA solutions increased potential CDR rates by up to 2.5-fold by promoting the abiotic dissolution of basalt and upregulating microbial siderophore production to further accelerate weathering reactions. Moreover, EDDHA may alleviate potential Fe limitation of crops due to rising soil pH with EW over time. Initial cost-benefit analysis suggests potassium-EDDHA could lower EW-CDR costs by up to U.S. $77 t CO2 ha-1 to improve EW's competitiveness relative to other CDR strategies.

Superficial versus deep parasternal intercostal plane blocks: cadaveric evaluation of injectate spread.

BACKGROUND: Deep and superficial parasternal intercostal plane blocks provide anterior chest wall analgesia for both breast and cardiac surgery. Our primary objective of this cadaveric study was to describe the parasternal spread of deep and superficial parasternal intercostal plane blocks. Our secondary objectives were to describe needle proximity to the internal mammary artery when performing deep parasternal intercostal plane blocks, and compare lateral injectate spread and extension into the rectus sheath. METHODS: We performed ultrasound-guided deep and superficial parasternal intercostal plane blocks 2 cm from the sternum at the T3-4 interspace in four fresh frozen cadavers as described in clinical studies. RESULTS: Parasternal spread of injectate was greater with the deep parasternal intercostal plane injection than with the superficial parasternal intercostal plane injection. The internal mammary artery was ∼3 mm away from the needle trajectory in cadaver #1 and ∼5 mm from the internal mammary artery in cadaver #2. Lateral spread extended to the midclavicular line for all deep parasternal intercostal plane blocks and beyond the midclavicular line for all superficial parasternal intercostal plane blocks. Neither block extended to the rectus sheath. CONCLUSIONS: A greater number of parasternal interspaces were covered with the deep parasternal intercostal plane block than with the superficial parasternal intercostal plane block when one injection was performed at the T3-4 interspace. However, considering proximity to the internal mammary artery, and potential devastating consequences of an arterial injury, we propose that the deep parasternal intercostal plane block be classified as an advanced block and that future studies focus on optimising superficial parasternal intercostal plane parasternal spread.

Mode of Fixation and Survivorship in Primary Total Knee Arthroplasty in the American Joint Replacement Registry.

BACKGROUND: A recent rapid increase in cementless total knee arthroplasty (TKA) has been noted in the American Joint Replacement Registry (AJRR). The purpose of our study was to compare TKA survivorship based on the mode of fixation reported to the AJRR in the Medicare population. METHODS: Primary TKAs from Medicare patients submitted to AJRR from 2012 to 2022 were analyzed. The Medicare and AJRR databases were merged. Cox regression stratified by sex compared revision outcomes (all-cause, infection, mechanical loosening, and fracture) for cemented, cementless, and hybrid fixation, controlling for age and the Charlson comorbidity index (CCI). RESULTS: A total of 634,470 primary TKAs were analyzed. Cementless TKAs were younger (71.8 versus 73.1 years, P < .001) than cemented TKAs and more frequently utilized in men (8.2 versus 5.8% women, P < .001). Regional differences were noted, with cementless fixation more common in the Northeast (10.5%) and South (9.2%) compared to the West (4.4%) and Midwest (4.3%) (P < .001). No significant differences were identified in all-cause revision rates in men or women ≥ 65 for cemented, cementless, or hybrid TKA after adjusting for age and CCI. Significantly lower revision for fracture was identified for cemented compared to cementless and hybrid fixation in women ≥ 65 after adjusting for age and CCI (P = .0169). CONCLUSIONS: No survivorship advantage for all-cause revision was noted based on the mode of fixation in men or women ≥ 65 after adjusting for age and CCI. A significantly lower revision rate for fractures was noted in women ≥ 65 utilizing cemented fixation. Cementless fixation in primary TKA should be used with caution in elderly women.

Anesthetic Management and Deep Sedation After Emergence From General Anesthesia: A Retrospective Cohort Study.

BACKGROUND: Residual deep sedation during anesthesia recovery may predict postoperative complications. We examined the incidence and risk factors for deep sedation after general anesthesia. METHODS: We retrospectively reviewed health records of adults who underwent procedures with general anesthesia and were admitted to the postanesthesia care unit from May 2018 to December 2020. Patients were dichotomized by Richmond Agitation-Sedation Scale (RASS) score: ≤-4 (deeply sedated/unarousable) or ≥-3 (not deeply sedated). Anesthesia risk factors for deep sedation were assessed with multivariable logistic regression. RESULTS: Of the 56,275 patients included, 2003 had a RASS ≤-4 (35.6 [95% CI, 34.1-37.2] cases per 1000 anesthetics administered). On adjusted analyses, the likelihood of a RASS ≤-4 increased when more soluble halogenated anesthetics were used. Compared with desflurane without propofol, the odds ratio (OR [95% CI]) for a RASS ≤-4 was higher with sevoflurane (1.85 [1.45-2.37]) and isoflurane (4.21 [3.29-5.38]) without propofol. Compared with desflurane without propofol, the odds of a RASS ≤-4 further increased with use of desflurane-propofol (2.61 [1.99-3.42]), sevoflurane-propofol (4.20 [3.28-5.39]), isoflurane-propofol (6.39 [4.90-8.34]), and total intravenous anesthesia (2.98 [2.22-3.98]). A RASS ≤-4 was also more likely with the use of dexmedetomidine (2.47 [2.10-2.89]), gabapentinoids (2.17 [1.90-2.48]), and midazolam (1.34 [1.21-1.49]). Deeply sedated patients discharged to general care wards had higher odds of opioid-induced respiratory complications (2.59 [1.32-5.10]) and higher odds of naloxone administration (2.93 [1.42-6.03]). CONCLUSIONS: Likelihood of deep sedation after recovery increased with intraoperative use of halogenated agents with higher solubility and increased further when propofol was concomitantly used. Patients who experience deep sedation during anesthesia recovery have an increased risk of opioid-induced respiratory complications on general care wards. These findings may be useful for tailoring anesthetic management to reduce postoperative oversedation.

Hemodynamics in Patients With Pheochromocytoma or Paraganglioma Undergoing Non-neuroendocrine Operations.

INTRODUCTION: Surgical resection of pheochromocytoma and paraganglioma (PPGL) may be associated with excessive hemodynamic variability. Whether hemodynamic variability occurs in patients with undiagnosed PPGL undergoing unrelated, non-neuroendocrine, operations is unknown. METHODS: We identified patients who underwent non-neuroendocrine surgical procedures up to 5 y before pathologic diagnosis of PPGL. For each PPGL, two non-PPGL patients were matched based on sex, age, type, and year of operation. Electronic medical records were reviewed for intraoperative blood pressures, heart rates, and hemodynamic variability was assessed with range (maximum-minimum), standard deviation, coefficient of variation, and average real variability. RESULTS: Thirty-seven PPGL patients underwent operations preceding the diagnosis of PPGL: 25 pheochromocytomas, 11 paragangliomas, and one metastatic pheochromocytoma. Median interquartile range tumor size at diagnosis was 35 mm (23 to 60). The time from index operation to PPGL diagnosis was ≤12 mo in 21 (56.8%) patients. In 23 (62.2%) patients, the subsequently diagnosed PPGL was functional. Fifteen (40.5%) PPGL and 20 (27.0%) control patients were preoperatively treated for hypertension (P = 0.149). Maximum intraoperative systolic BP was >180 mmHg for 4 (10.8%) PPGL patients and 3 (4.1%) controls (P = 0.219). Two PPGL patients had intraoperative systolic BP >230 mmHg. No significant differences were found with all other measures of intraoperative hemodynamic variability. Similarly, in secondary analysis there was no significant difference in intraoperative hemodynamic variability between biochemically active PPGL and their respective controls. CONCLUSIONS: Patients with undiagnosed PPGL undergoing a wide variety of non-neuroendocrine operations had intraoperative hemodynamic variability comparable to non-PPGL patients undergoing the same type of procedures.

Vascular Response Toward an Absorbable Sirolimus-eluting Polymeric Scaffold for Vascular Application in a Model of Normal Porcine Carotid Arteries.

BACKGROUND: Fully absorbable polymeric scaffolds, as a potential alternative to permanent metallic stents, are entering the clinical field. The aim of this study is to assess the in vivo biocompatibility of a novel Sirolimus-eluting (SIR) absorbable scaffold based on poly(L-lactide) (PLLA) and poly(4-hydroxybutyrate) (P4HB) for interventional application. METHODS: Absorbable PLLA/P4HB scaffolds either loaded with SIR coating or unloaded scaffolds were implanted interventionally into common carotid arteries of 14 female. Bare metal stents (BMS) served as control. Peroral dual anti-platelet therapy was administered throughout the study. Stented common carotid arteries segments were explanted after 4 weeks, and assessed histomorphometrically. RESULTS: The absorbable scaffolds showed a decreased residual lumen area and higher stenosis after 4 weeks (PLLA/P4HB: 6.56 ± 0.41 mm² and 37.56 ± 4.67%; SIR-PLLA/P4HB: 6.90 ± 0.58 mm² and 35.60 ± 3.15%) as compared to BMS (15.29 ± 1.86 mm² and 7.65 ± 2.27%). Incorporation of SIR reduced the significantly higher inflammation of unloaded scaffolds however not to a level compared to bare metal stent (PLLA/P4HB: 1.20 ± 0.19; SIR-PLLA/P4HB: 0.96 ± 0.24; BMS: 0.54 ± 0.12). In contrast, the BMS showed a slightly elevated vascular injury score (0.74 ± 0.15), as compared to the PLLA/P4HB (0.54 ± 0.20) and the SIR-PLLA/P4HB (0.48 ± 0.15) groups. CONCLUSION: In this preclinical model, the new absorbable polymeric (SIR-) scaffolds showed similar technical feasability and safety for vascular application as the permanent metal stents. The higher inflammatory propensity of the polymeric scaffolds was slightly reduced by SIR-coating. A smaller strut thickness of the polymeric scaffolds might have been a positive effect on tissue ingrowth between the struts and needs to be addressed in future work on the stent design.

Photobacterium damsela Necrotizing Fasciitis of the Arm.

Photobacterium damsela is a gram-negative bacterium that is known to cause infection, most commonly in marine animals and rarely in humans. Photobacterium damsela typically results in skin and soft tissue infections in humans and has been associated with necrotizing fasciitis in several case reports. After an initially benign presentation, P damsela necrotizing fasciitis often progresses rapidly to multiorgan failure and death. Here, we present a fatal case of P damsela necrotizing fasciitis after a minor cut while scaling a fish with a discussion of current literature and treatment strategies.

The effects of shoulder arthroscopy on ultrasound image quality of the interscalene brachial plexus: a pre-procedure vs post-procedure comparative study.

BACKGROUND: Fluid extravasation from the shoulder compartment and subsequent absorption into adjacent soft tissue is a well-documented phenomenon in arthroscopic shoulder surgery. We aimed to determine if a qualitative difference in ultrasound imaging of the interscalene brachial plexus exists in relation to the timing of performing an interscalene nerve block (preoperative or postoperative). METHODS: This single-center, prospective observational study compared pre- and postoperative interscalene brachial plexus ultrasound images of 29 patients undergoing shoulder arthroscopy using a pretest-posttest methodology where individual patients served as their own controls. Three fellowship-trained regional anesthesiologists evaluated image quality and confidence in performing a block for each ultrasound scan using a five-point Likert scale. The association of image quality with age, gender, BMI, duration of surgery, obstructive sleep apnea, and volume of arthroscopic irrigation fluid were analyzed as secondary outcomes. RESULTS: Aggregate preoperative mean scores in quality of ultrasound visualization were higher than postoperative scores (preoperative 4.5 vs postoperative 3.8; p < .001), as was confidence in performing blockade based upon the imaging (preoperative 4.8 vs postoperative 4.2; p < .001). Larger BMI negatively affected visualization of the brachial plexus in the preoperative period (p < 0.05 for both weight categories). Patients with intermediate-high risk or confirmed obstructive sleep apnea had lower aggregate postoperative mean scores compared to the low-risk group for both ultrasound visualization (3.4 vs 4.0; p < .05) and confidence in block performance (3.8 vs 4.4; p < .05). CONCLUSION: Due to the potential reduction of ultrasound visualization of the interscalene brachial plexus after shoulder arthroscopy, we advocate for a preoperative interscalene nerve block when feasible. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT03657173 ; September 4, 2018).

Exposure to surgery with general anaesthesia during adult life is not associated with increased brain amyloid deposition in older adults.

BACKGROUND: Exposure to surgery with general anaesthesia (surgery/GA) is associated with cortical atrophy, but the aetiology remains unknown. Amyloid-ß (Aß) deposition is one of the hallmark pathological characteristics of Alzheimer's disease (AD). We examined brain Aß burden in study participants exposed to surgery/GA. METHODS: We performed a cross-sectional analysis of residents of Olmsted County, MN, USA, in the Mayo Clinic Study of Aging who were aged 70-97 yr and underwent measurement of (i) brain Aß with Pittsburgh compound B positron emission tomography (PiB PET), (ii) brain glucose metabolism with 18-fluorodeoxyglucose (FDG) PET, and (iii) temporal cortical thickness with MRI. Separate analyses were performed with exposure to surgery/GA, defined as occurring after age 40 yr, and with exposure to surgery/GA, defined as occurring within 20 yr before neuroimaging. Imaging measurements were compared between participants who were exposed to surgery/GA vs not exposed. RESULTS: Of the 2563 participants, 585 had PET scans. Regardless of the definition used to quantify exposure, no significant associations were detected between exposure and either global PiB PET or FDG PET. In contrast, exposure to surgery/GA was associated with an increased likelihood of abnormal cortical thinning: odds ratio (OR)=1.98 (95% confidence interval [CI]: 1.19-3.31); P=0.010 in those exposed after age 40 yr, and OR=1.64 (95% CI: 1.05-2.55); P=0.029 in those exposed in the prior 20 yr. CONCLUSIONS: Exposure to surgery/GA is not associated with increases in cortical amyloid deposition. This finding suggests that the modest cortical thinning associated with surgery/GA is not related to AD pathology, but rather is caused by other processes.

Anesthesia With and Without Nitrous Oxide and Long-term Cognitive Trajectories in Older Adults.

BACKGROUND: We evaluated the hypothesis that the rate of postoperative decline in global cognition is greater in older adults exposed to general anesthesia with nitrous oxide (N2O) compared to general anesthesia without N2O. METHODS: Longitudinal measures of cognitive function were analyzed in nondemented adults, 70-91 years of age, enrolled in the Mayo Clinic Study of Aging. Linear mixed-effects models with time-varying covariates assessed the relationship between exposure to surgery with general anesthesia (surgery/GA) with or without N2O and the rate of long-term cognitive changes. Global cognition and domain-specific cognitive outcomes were defined using z scores, which measure how far an observation is, in standard deviations, from the unimpaired population mean. RESULTS: The analysis included 1819 participants: 280 exposed to GA without N2O following enrollment and before censoring during follow-up (median [interquartile range {IQR}] follow-up of 5.4 [3.9-7.9] years); 256 exposed to GA with N2O (follow-up 5.6 [4.0-7.9] years); and 1283 not exposed to surgery/GA (follow-up 4.1 [2.5-6.4] years). The slope of the global cognitive z score was significantly more negative following exposure to surgery/GA after enrollment (change in slope of -0.062 [95% confidence interval {CI}, -0.085 to -0.039] for GA without N2O, and -0.058 [95% CI, -0.080 to -0.035] for GA with N2O, both P < .001). The change in slope following exposure to surgery/GA did not differ between those exposed to anesthesia without versus with N2O (estimated difference -0.004 [95% CI, -0.035 to 0.026], P = .783). CONCLUSIONS: Exposure to surgery/GA is associated with a small, but statistically significant decline in cognitive z scores. Cognitive decline did not differ between anesthetics with and without N2O. This finding provides evidence that the use of N2O in older adults does not need to be avoided because of concerns related to decline in cognition.

Outcomes After Noncardiac Surgery for Patients with Pulmonary Hypertension: A Historical Cohort Study.

OBJECTIVE: Pulmonary hypertension (PH) is a substantial preoperative risk factor. For this study, morbidity and mortality were examined after noncardiac surgery in patients with precapillary PH. DESIGN: A retrospective cohort study. SETTING: Quaternary medical center in Rochester, MN. PARTICIPANTS: Adults with PH undergoing noncardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The PH and surgical databases were reviewed from 2010 to 2017. Patients were excluded if PH was attributable to left-sided heart disease or they had undergone cardiac or transplantation surgeries. To assess whether PH-specific diagnostic or cardiopulmonary testing parameters were predictive of perioperative complications, generalized estimating equations were used. Of 196 patients with PH, 53 (27%) experienced 1 or more complications, including 5 deaths (3%) within 30 days. After adjustment for age and PH type, there were more complications in those undergoing moderate- to high-risk versus low-risk procedures (odds ratio [OR] 4.17 [95% confidence interval {CI} 2.07-8.40]; p < 0.001). After adjustment for age, surgical risk, and PH type, the complication risk was greater for patients with worse functional status (OR 2.39 [95% CI 1.19-4.78]; p = 0.01 for classes III/IV v classes I/II) and elevated serum N-terminal fragment of the prohormone brain natriuretic peptide (NT-proBNP) (OR 2.28 [95% CI 1.05-4.96]; p = 0.04 for ≥300 v <300 pg/mL). After adjusting for age, surgical risk, and functional status, elevated NT-proBNP remained associated with increased risk (OR 2.23 [95% CI 1.05-4.76]; p = 0.04). CONCLUSION: PH patients undergoing noncardiac surgery have a high frequency of complications. Worse functional status, elevated serum NT-proBNP, and higher-risk surgery are predictive of worse outcome.

Postoperative Pain Protocol in Children after Selective Dorsal Rhizotomy.

INTRODUCTION: Selective dorsal rhizotomy (SDR) provides lasting relief of spasticity for children suffering from cerebral palsy, although controlling postoperative pain is challenging. Postoperatively, escalation of therapies to include a patient-controlled analgesia (PCA) pump and intensive care unit (ICU) admission is common. OBJECTIVES: We developed a multimodal pain management protocol that included intraoperative placement of an epidural catheter with continuous opioid administration. We present the 3-year results of protocol implementation. METHODS: With institutional review board approval, all patients who were subjected to SDR at our institution were identified for review. Hourly pain scores were recorded. Adverse effects of medication, including desaturation, nausea/vomiting, and pruritus, were also noted. Comparisons were made between patients treated with PCA and those treated with multimodal pain control using t and χ2 tests as appropriate. RESULTS: Thirty-nine patients undergoing the procedure with protocolized pain control (average age 6.8 years, 57% male) were compared to 7 PCA-treated controls (average age 6.6 years, 54% male). Pain control was satisfactory in both groups, with average pain scores of 1.5 in both groups on postoperative day 0, decreasing by postoperative day 3 to 1.1 in the PCA group and 0.5 in the protocol group. No patients under the protocol required ICU admission; all patients with PCA spent at least 1 day in the ICU. Desaturations were seen in 16 patients in the protocol group (41%), but none required ICU transfer. Treatment for pruritis was given to 57% of PCA patients and 15% of protocol patients. Treatment for nausea and vomiting was given to 100% of PCA patients and 51% of protocol patients. Medication requirements for the hospitalization were decreased from 1.1 to 0.28 doses per patient for pruritis, and from 3 to 1.1 doses per patient for nausea. CONCLUSIONS: Multimodal analgesia is an excellent alternative to PCA for postoperative pain after SDR. Actual analgesia is comparative to that of controls without the need for intensive care monitoring. Side effects of high-dose opiates were less frequent and required less medication. With the protocol, patients were safely treated outside the ICU.

Association Between Critical Care Admissions and Cognitive Trajectories in Older Adults.

OBJECTIVES: Patients requiring admission to an ICU may subsequently experience cognitive decline. Our objective was to investigate longitudinal cognitive trajectories in older adults hospitalized in ICUs. We hypothesized that individuals hospitalized for critical illness develop greater cognitive decline compared with those who do not require ICU admission. DESIGN: A retrospective cohort study using prospectively collected cognitive scores of participants enrolled in the Mayo Clinic Study of Aging and ICU admissions retrospectively ascertained from electronic medical records. A covariate-adjusted linear mixed effects model with random intercepts and slopes assessed the relationship between ICU admissions and the slope of global cognitive z scores and domains scores (memory, attention/executive, visuospatial, and language). SETTING: ICU admissions and cognitive scores in the Mayo Clinic Study of Aging from October 1, 2004, to September 11, 2017. PATIENTS: Nondemented participants age 50 through 91 at enrollment in the Mayo Clinic Study of Aging with an initial cognitive assessment and at least one follow-up visit. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 3,673 participants, 372 had at least one ICU admission with median (25-75th percentile) follow-up after first ICU admission of 2.5 years (1.2-4.4 yr). For global cognitive z score, admission to an ICU was associated with greater decline in scores over time compared with participants not requiring ICU admission (difference in annual slope = -0.028; 95% CI, -0.044 to -0.012; p < 0.001). ICU admission was associated with greater declines in memory (-0.029; 95% CI, -0.047 to -0.011; p = 0.002), attention/executive (-0.020; 95% CI, -0.037 to -0.004; p = 0.016), and visuospatial (-0.013; 95% CI, -0.026 to -0.001; p = 0.041) domains. ICU admissions with delirium were associated with greater declines in memory (interaction p = 0.006) and language (interaction p = 0.002) domains than ICU admissions without delirium. CONCLUSIONS: In older adults, ICU admission was associated with greater long-term cognitive decline compared with patients without ICU admission. These findings were more pronounced in those who develop delirium while in the ICU.

Improving the rate of surgical normothermia in gynecologic surgery.

OBJECTIVE: To increase the rate of normothermia (core temperature ≥ 36 °C) in patients undergoing gynecologic surgery. METHODS: The rate of surgical normothermia was evaluated in a single institution. A two-phase quality improvement project was undertaken; Phase 1 included the use of intra-operative room temperature regulation and intra-operative patient warming and Phase 2 included pre-operative patient warming. Clinical characteristics, median temperatures, and rate of normothermia were abstracted for patients in each phase. Cohorts were compared using chi-square and t-tests. RESULTS: The project was performed in two phases, each with a historic and intervention cohort. There were 503 patients in the historical cohort and 636 patients in the intervention cohort in phase 1; there were 291 patients in the historical cohort and 259 patients in the intervention cohort for Phase 2. Patient characteristics and anesthetic type and duration did not differ between cohorts. After intra-operative temperature regulation and patient warming in Phase 1, significantly more patients achieved normothermia (79% versus 68%, P < 0.0001). However operating room staff were more likely to rate the temperature as very hot in 40% of cases post-intervention, compared to only 2% historically. In Phase 2, after the intervention of pre-warming patients, there was no difference in achieving normothermia, 78% versus 83%, P = 0.09. Staff had no statistical difference in personal comfort with the temperature, however did feel efforts were very effective more frequently, 7.7% historic versus 32.7% post-intervention, P < 0.0001. CONCLUSIONS: Quality improvement methodology can be applied to pre- and intra-operative decision making to improve rates of surgical patient normothermia.

Cardiac Risk Factors and Complications After Spinal Fusion for Idiopathic Scoliosis in Children.

BACKGROUND: Cardiac risk factors pose challenges in pediatric posterior spinal fusion (PSF). Differences in risk according to etiology of cardiac disease are unclear. We investigated outcomes of PSF according to presence of congenital heart defect compared to cardiomyopathy. METHODS: Elective PSF for idiopathic scoliosis in patients aged 0-18 y was identified in the 2012-2015 National Surgical Quality Improvement Program-Pediatric. Cardiac risk factors were classified as: no cardiac risk factors or minor cardiac risk factors without congenital heart defect; minor cardiac risk factors because of congenital heart defect; major cardiac risk factors because of congenital heart defect; major cardiac risk factors because of cardiomyopathy. Multivariable logistic regression compared surgical site infection, wound dehiscence, hospital length of stay ≥30 d, and unplanned readmission across these categories. RESULTS: The analysis included 5395 girls and 1691 boys, aged 14 ± 2 y. Among these, 140 patients had minor cardiac risk factors because of congenital heart defect, 144 had major cardiac risk factors because of congenital heart defect, and 20 had major cardiac risk factors because of cardiomyopathy. Rates of any complication were significantly higher among patients with cardiomyopathy (40%) compared to patients with major cardiac risk factors because of congenital heart defect (10%), minor cardiac risk factors because of congenital heart defect, or other minor or no cardiac risk factors (5%; chi-square P < 0.001). In multivariable analysis of 6829 patients, cardiomyopathy predicted greater odds of unplanned readmission compared to no or minor cardiac risk factors (OR = 5.9; 95% CI: 1.8, 19.7; P = 0.004) and compared to major cardiac risk factors because of congenital heart defect (OR = 4.5; 95% CI: 1.1, 17.6; P = 0.032). CONCLUSIONS: Cardiomyopathy is a rare but significant risk factor for complications after pediatric PSF, whereas congenital heart defects did not independently contribute to risk of complications after this procedure.

Exposure to surgery under general anaesthesia and brain magnetic resonance imaging changes in older adults.

BACKGROUND: Preclinical studies suggest that exposure to general anaesthesia (GA) could cause neurodegeneration consistent with Alzheimer's disease (AD) pathology. Brain magnetic resonance imaging (MRI) is useful to study structural brain changes. We tested the hypothesis that exposure to surgery with GA (surgery/GA) is associated with greater cortical thinning and increased frequency of white matter lesions. METHODS: This is a cross-sectional analysis of 70-91-yr-old participants enrolled in the Mayo Clinic Study of Aging who had baseline MRI. The thickness of selected cortical regions, the volume of white matter hyperintensities, and the frequency of cortical infarctions were compared in participants who were and were not exposed to surgery/GA within 20 yr before the first MRI obtained after enrolment. RESULTS: Of 1410 participants with MRI scans, 932 were exposed to surgery/GA before scanning. In adjusted analyses, cortical thickness in regions vulnerable to AD was significantly less in those exposed to surgery/GA in the prior 20 yr (difference -0.023 mm, [95% confidence interval (CI) -0.041 to -0.005], P=0.014). Those with surgery in the prior 20 yr were more likely to have 'abnormal thickness' compared with those without surgery (odds ratio=1.45, [95% CI 1.10-1.90], P=0.009). Exposure was not associated with white matter hyperintensities or the presence of brain infarcts. CONCLUSIONS: This study suggests that exposure of older adults to surgical anaesthesia is associated with thinning in cortical regions implicated in AD. The pathogenesis and mechanisms driving these neurodegenerative changes, and the potential clinical significance of these findings, require further study.

Postoperative Corneal Injuries: Incidence and Risk Factors.

BACKGROUND: Previous studies of postoperative corneal injury rates relied on provider-initiated incident reports, which may underestimate the true incidence. Postoperative administration of proparacaine eye drops is used almost exclusively to diagnose corneal injury; therefore, identifying instances of administration may provide a better estimate of corneal injuries. We compared proparacaine administration versus provider-initiated reports to determine rates of corneal injury. In addition, potential associations between clinical variables and injury were assessed with a matched case-control study. METHODS: The health records of 132,511 sequential adult postanesthesia recovery room admissions (January 1, 2011 to June 30, 2017) were reviewed to identify postoperative proparacaine administration and incident reports of corneal injury. Patients with corneal injury were matched with control patients at a 1:2 ratio to assess factors associated with injury. RESULTS: Proparacaine drops were administered to 442 patients (425 patients received proparacaine for diagnosis and 17 patients received proparacaine for unrelated reasons). Incident reports identified 320 injuries, and the aggregate corneal injury count was 436 (incidence, 3.3 injuries [95% confidence interval {CI}, 3.0-3.6] per 1000 cases of general anesthesia). Proparacaine administration had a greater case ascertainment percentage than incident reporting (97.5% vs 73.4%; P < .001). The matched case-control analysis found greater risks associated with longer duration of anesthesia (odds ratio, 1.05 [95% CI, 1.03-1.07] per 10 minutes of anesthesia; P < .001) and nonsupine surgical position (odds ratio, 3.89 [95% CI, 2.17-6.98]; P < .001). Patients with injuries also had more evidence of sedation and agitation during anesthesia recovery. CONCLUSIONS: Calculation of incidence by using the administration of a medication (proparacaine eye drops) that is almost exclusively used to diagnose a specific injury (corneal injury) showed higher case ascertainment percentage than incident-reporting methods. Similar strategies could be used to monitor the rates of other adverse events.

Emergency Manual Implementation in a Large Academic Anesthesia Practice: Strategy and Improvement in Performance on Critical Steps.

BACKGROUND: The use of cognitive aids, such as emergency manuals (EMs), improves team performance on critical steps during crisis events. In our large academic anesthesia practice, we sought to broadly implement an EM and subsequently evaluate team member performance on critical steps. METHODS: We observed the phases of implementing an EM at a large academic anesthesia practice from 2013 to 2016, including the formation of the EM implementation team, identification of preferred EM characteristics, consideration of institution-specific factors, selection of the preferred EM, recognition of logistical barriers, and staff education. Utilization of the EM was tested in a regular clinical environment with all available resources using a standardized verbal simulation of 3 crisis events both preimplementation and 6 months postimplementation. Individual members of the anesthesia team were asked to verbalize interventions for specific crisis events over 60 seconds. RESULTS: We introduced a customized version of the Stanford Emergency Manual on January 26, 2015. Fifty-nine total participants (equal proportion of anesthesiology attending physicians, resident physicians, certified registered nurse anesthetists, and student registered nurse anesthetist staff) were surveyed in the preimplementation phase and 60 in the 6-month postimplementation phase. In the postimplementation phase, a minority (41.7%) utilized the EM for the verbal-simulated crisis events. Those who used the EM performed better than those who did not (median 21.0 critical steps out of a possible 30 total steps [70.0%], interquartile range 19-25 vs 18.0 critical steps verbalized [60.0%], interquartile range 16-20; P < .001). Among all subjects, the median number of critical steps verbalized was 16 (53.3%) preimplementation and 19.5 critical steps (65.0%) postimplementation. CONCLUSIONS: Implementation of an EM in a large academic anesthesia practice is not without challenges. While full integration of the EM was not achieved 6 months after implementation, verbalization of critical steps on 3 simulated crisis events improved when the EM was utilized.

Interspace between Popliteal Artery and posterior Capsule of the Knee (IPACK) Injectate Spread: A Cadaver Study.

OBJECTIVES: Local anesthetic injection into the interspace between the popliteal artery and the posterior capsule of the knee (IPACK) has the potential to provide motor-sparing analgesia to the posterior knee after total knee arthroplasty. The primary objective of this cadaveric study was to evaluate injectate spread to relevant anatomic structures with IPACK injection. METHODS: After receipt of Institutional Review Board Biospecimen Subcommittee approval, IPACK injection was performed on fresh-frozen cadavers. The popliteal fossa in each specimen was dissected and examined for injectate spread. RESULTS: Ten fresh-frozen cadaver knees were included in the study. Injectate was observed to spread in the popliteal fossa at a mean ± SD of 6.1 ± 0.7 cm in the medial-lateral dimension and 10.1 ± 3.2 cm in the proximal-distal dimension. No injectate was noted to be in contact with the proximal segment of the sciatic nerve, but 3 specimens showed injectate spread to the tibial nerve. In 3 specimens, the injectate showed possible contact with the common peroneal nerve. The middle genicular artery was consistently surrounded by injectate. CONCLUSIONS: This cadaver study of IPACK injection demonstrated spread throughout the popliteal fossa without proximal sciatic involvement. However, the potential for injectate to spread to the tibial or common peroneal nerve was demonstrated. Consistent surrounding of the middle genicular artery with injectate suggests a potential mechanism of analgesia for the IPACK block, due to the predictable relationship between articular sensory nerves and this artery. Further study is needed to determine the ideal site of IPACK injection.

Cognitive function after surgery with regional or general anesthesia: A population-based study.

INTRODUCTION: Our aim was to examine whether surgery with regional anesthesia (RA) is associated with accelerated long-term cognitive decline comparable with that previously reported after general anesthesia (GA). METHODS: Longitudinal cognitive function was analyzed in a cohort of 1819 older adults. Models assessed the rate of change in global and domain-specific cognition over time in participants exposed to RA or GA. RESULTS: When compared with those unexposed to anesthesia, the postoperative rate of change of the cognitive global z-score was greater in those exposed to both RA (difference in annual decline of -0.041, P = .011) and GA (-0.061, P < .001); these rates did not differ. In analysis of the domain-specific scores, an accelerated decline in memory was observed after GA (-0.065, P < .001) but not RA (-0.011, P = .565). CONCLUSIONS: Older adults undergoing surgery with RA experience decline of global cognition similar to those receiving GA; however, memory was not affected.