Does the Location of Endotracheal Intubation Affect the Success of Airway Management in a Helicopter Air Ambulance Service? A Simulation Study.

OBJECTIVE: Airway management is a cornerstone of helicopter air ambulance patient management. The purpose of this study was to evaluate the overall quality of airway management of critical care crews in 3 common locations for intubation. METHODS: This was a prospective observational simulation study assessing the overall airway management of critical care providers managing simulated patients in an emergency department, helicopter, and ambulance. Composite scores were obtained and compared with respect to physical environment and provider certification level. RESULTS: Fifty-four participants completed the simulations. The median score for the emergency department was 100; for ambulance, it was 80; and for helicopter, it was 80. Ambulance scores were significantly lower than emergency department scores (median difference = -5 points, P = .002) as were helicopter scores (median difference = -10 points, P < .001). The small sample size limited the statistical power to detect differences in provider type, and no statistically significant differences were found in these groups. CONCLUSION: In this study, the physical location of airway management negatively impacted the overall airway management success as determined by a standardized composite score. This suggests that airway management may have the highest rate of success in an emergency department as opposed to ground ambulance or helicopter air ambulance settings.

Robotic Versus Laparoscopic Ventral Hernia Repair: Two-Year Results From a Prospective, Multicenter, Blinded Randomized Clinical Trial.

OBJECTIVE: Report the 2-year outcomes of a multicenter randomized controlled trial comparing robotic versus laparoscopic intraperitoneal onlay mesh ventral hernia repair. BACKGROUND: Ventral hernia repair is one of the most common operations performed by general surgeons. To our knowledge, no studies have been published to date comparing long-term outcomes of laparoscopic versus robotic ventral hernia repair. METHODS: The trial was registered at clinicaltrials.gov (NCT03490266). Clinical outcomes included surgical site infection, surgical site occurrence, hernia occurrence, readmission, reoperation, and mortality. RESULTS: A total of 175 consecutive patients were approached that were deemed eligible for elective minimally invasive ventral hernia repair. In all, 124 were randomized and 101 completed follow-up at 2 years. Two-year follow-up was completed in 54 patients (83%) in the robotic arm and 47 patients (80%) in the laparoscopic arm. No differences were seen in surgical site infection or surgical site occurrence. Hernia recurrence occurred in 2 patients (4%) receiving robotic repair versus in 6 patients (13%) receiving laparoscopic repair (relative risk: 0.3, 95% CI: 0.06-1.39; P =0.12). No patients (0%) required reoperation in the robotic arm whereas 5 patients (11%) underwent reoperation in the laparoscopic arm ( P =0.019, relative risk not calculatable due to null outcome). CONCLUSIONS: Robotic ventral hernia repair demonstrated at least similar if not improved outcomes at 2 years compared with laparoscopy. There is potential benefit with robotic repair; however, additional multi-center trials and longer follow-up are needed to validate the hypothesis-generating findings of this study.

Prediction of major postoperative events after non-cardiac surgery for people with kidney failure: derivation and internal validation of risk models.

BACKGROUND: People with kidney failure often require surgery and experience worse postoperative outcomes compared to the general population, but existing risk prediction tools have excluded those with kidney failure during development or exhibit poor performance. Our objective was to derive, internally validate, and estimate the clinical utility of risk prediction models for people with kidney failure undergoing non-cardiac surgery. DESIGN, SETTING, PARTICIPANTS, AND MEASURES: This study involved derivation and internal validation of prognostic risk prediction models using a retrospective, population-based cohort. We identified adults from Alberta, Canada with pre-existing kidney failure (estimated glomerular filtration rate [eGFR] < 15 mL/min/1.73m2 or receipt of maintenance dialysis) undergoing non-cardiac surgery between 2005-2019. Three nested prognostic risk prediction models were assembled using clinical and logistical rationale. Model 1 included age, sex, dialysis modality, surgery type and setting. Model 2 added comorbidities, and Model 3 added preoperative hemoglobin and albumin. Death or major cardiac events (acute myocardial infarction or nonfatal ventricular arrhythmia) within 30 days after surgery were modelled using logistic regression models. RESULTS: The development cohort included 38,541 surgeries, with 1,204 outcomes (after 3.1% of surgeries); 61% were performed in males, the median age was 64 years (interquartile range [IQR]: 53, 73), and 61% were receiving hemodialysis at the time of surgery. All three internally validated models performed well, with c-statistics ranging from 0.783 (95% Confidence Interval [CI]: 0.770, 0.797) for Model 1 to 0.818 (95%CI: 0.803, 0.826) for Model 3. Calibration slopes and intercepts were excellent for all models, though Models 2 and 3 demonstrated improvement in net reclassification. Decision curve analysis estimated that use of any model to guide perioperative interventions such as cardiac monitoring would result in potential net benefit over default strategies. CONCLUSIONS: We developed and internally validated three novel models to predict major clinical events for people with kidney failure having surgery. Models including comorbidities and laboratory variables showed improved accuracy of risk stratification and provided the greatest potential net benefit for guiding perioperative decisions. Once externally validated, these models may inform perioperative shared decision making and risk-guided strategies for this population.

Robotic Versus Laparoscopic Ventral Hernia Repair: One-year Results From a Prospective, Multicenter, Blinded Randomized Controlled Trial.

OBJECTIVE: The aim of this study was to compare clinical and patient-reported outcomes of robotic versus laparoscopic ventral hernia repair (LVHR) at 1-year postoperative. SUMMARY OF BACKGROUND DATA: Despite a relative lack of research at low risk for bias assessing robotic ventral hernia repair (RVHR), the growth of RVHR has been rapid. We previously reported short-term results of the first randomized control trial comparing RVHR versus LVHR; there was no clear difference in clinical outcomes but increased operative time and cost with robotic repair. METHODS: Patients from a multicenter, blinded randomized control trial comparing RVHR versus LVHR were followed at 1 year. Outcomes included wound complication (surgical site infection, surgical site occurrence, wound dehiscence), hernia occurrence including recurrence and port site hernia, readmission, reoperation, and patient-reported outcomes (functional status, pain, and satisfaction with repair and cosmesis). RESULTS: A total of 124 patients were randomized and 113 patients (91%; 60 robot, 53 laparoscopic) completed 1-year follow-up. Baseline demographics were similar in both groups. No differences were seen in wound complication (15% vs 15%; P = 0.899), hernia recurrence (7% vs 9%; P = 0.576), or readmission (2% vs 6%; P = 0.251). No patients underwent reoperation in the robotic arm, whereas 5 (9%) did in the laparoscopic arm (P = 0.020). No differences were seen in patient-reported outcomes. Both arms reported clinically significant improvements in functional status, low pain scores, and high satisfaction scores at 1-year post repair. CONCLUSION: This study confirms that robotic ventral hernia repair is safe when compared to laparoscopy. Further studies are needed to confirm these findings.

Outcomes of primary versus revisional robotically assisted laparoscopic Roux-en-Y gastric bypass: a multicenter analysis of ten-year experience.

BACKGROUND: Postoperative morbidity after laparoscopic bariatric surgery is considered higher for patients undergoing revisional versus primary procedures. The objective of this retrospective cohort study was to compare outcomes between patients undergoing primary versus revisional robotically assisted laparoscopic (RAL) Roux-en-Y gastric bypass (RYGB). METHODS: Data of all patients who underwent RAL primary and revisional RYGB between 2009 and 2019 at two accredited, high-volume bariatric surgery centers-the Memorial Hermann - Texas Medical Center, Houston, TX, and the Tower Health, Reading Hospital, Reading, PA, were analyzed. Primary outcomes were early (< 30 days) and overall postoperative complications. Secondary outcomes included intraoperative complications, operative times, conversions to laparotomy, length of hospital stay, early (< 30 days) postoperative readmissions and deaths. RESULTS: Data of 1072 patients were analyzed, including 806 primary and 266 revisional RAL RYGB procedures. Longer operative times (203 versus 154 min, P < 0.001), increased number of readmissions for oral intolerance (10.5% versus 6.7%, P = 0.046) and higher rate of gastrojejunal stricture (6.4% versus 2.7%, P = 0.013) were found in the revisional group. Gastrointestinal leak rates were 0.2% for the primary versus 1.1% for the revisional group (P = 0.101). Early (< 30 days) reoperations rates were 2.2% for the primary versus 1.1% for the revisional group (P = 0.318). There were no statistically significant differences between groups in overall and severe complication rates. CONCLUSION: Patients undergoing RAL primary and revisional RYGB had comparable overall outcomes, with a non-significant higher early complication rate in the revisional group. Despite the study being underpowered to detect differences in specific complication rates, the morbidity seen in the revisional RYGB group remains markedly below literature reports of revisional laparoscopic RYGB and might suggest a benefit of robotic assistance. Further prospective studies are needed to confirm these results.

Impact of a care delivery redesign initiative for vascular surgery.

OBJECTIVE: A hospital-wide quality improvement process through a care delivery redesign (CDR) was initiated to improve patient care efficiency, clinical documentation, and length of stay (LOS). The impact of CDR was assessed through LOS, unplanned readmission rates, and hospital financial metrics. METHODS: The CDR team consisted of the Chief of Vascular Surgery, inpatient nurse practitioner, dedicated case manager, clinical documentation improvement specialist, and vascular surgery residents and faculty. The nurse practitioner facilitated patient care coordination, resident system-based education, and multidisciplinary collaboration. Tools created to track performance and to ensure sustainability included daily discussions of patient care barriers and solutions; standardized order sets; a mobile app for residents containing resident service expectations, disease-specific resources, and vascular surgery journal links; and a weekly inpatient tracker showing real-time patient care data. Outcome measures included LOS, case mix index, contribution margin, and unplanned readmissions. Each outcome was determined for all inpatient admissions the year before and the 12 months after CDR was initiated. Outcomes were compared between the two groups. RESULTS: Implementation of CDR resulted in a 23% decrease in LOS (P = .003), reducing the gap to the Centers for Medicare and Medicaid Services geometric mean LOS from 2.1 days to 0.5 day (P < .001). Clinical documentation resulted in an increase in case mix index of 10% (P = .011). The 30-day unplanned readmission rates did not change in the 12 months after CDR was initiated compared with the year before (P = .92). Financial data demonstrated decreased variable cost and increased revenue resulting in a $1.89 million increase in contribution margin. CONCLUSIONS: A CDR predicated on a dedicated service line advanced practitioner, clinical documentation education, weekly service tracker review, and real-time management of system-related barriers to patient care is described. Implementation of the CDR reduced hospital LOS with no change in unplanned readmissions and provided significant financial benefit to the hospital by increasing revenue and decreasing variable cost.

Trocar site closure with a novel anchor-based (neoClose®) system versus standard suture closure: a prospective randomized controlled trial.

BACKGROUND: Patients with obesity have a higher risk of trocar site hernia. The objective of the present study was to compare a standard suture passer versus the neoClose® device for port site fascial closure in patients with obesity undergoing laparoscopic bariatric surgery. METHODS: This is a randomized, controlled trial with two parallel arms. Thirty five patients with BMI ≥ 35 kg/m2 and undergoing laparoscopic sleeve gastrectomy or Roux-en-Y gastric bypass were randomized to each group. Port site fascial closure for trocars ≥ 10 mm was performed with the neoClose® device in the study group and the standard suture passer in the control group. Primary outcomes were time required to complete closure and intensity of postoperative pain at the fascial closure sites. Secondary outcomes were intraabdominal needle depth and incidence of trocar site hernia. RESULTS: The use of the neoClose® device resulted in shorter closure times (20.2 vs 30.0 s, p = 0.0002), less pain (0.3 vs 0.9, p = 0.002) at port closure sites, and decreased needle depth (3.3 cm vs 5.2 cm, p < 0.0001) compared to the standard suture passer. There was no trocar site hernia at the one-year follow-up in either group. CONCLUSIONS: Use of the neoClose® device resulted in faster fascial closure times, decreased intraoperative needle depth, and decreased postoperative abdominal pain at 1 week as compared to the standard suture passer. These data need to be confirmed on larger cohorts of patients with longer follow-up.

Safety of robotic assisted laparoscopic recurrent paraesophageal hernia repair: insights from a large single institution experience.

BACKGROUND: Laparoscopic repair of recurrent as opposed to primary paraesophageal hernias (PEHs) are historically associated with increased peri-operative complication rates, worsened outcomes, and increased conversion rates. The robotic platform may aid surgeons in these complex revision procedures. The aim of this study was to compare the outcomes of patients undergoing robotic assisted laparoscopic (RAL) repair of recurrent as opposed to primary PEHs. METHODS: Patients undergoing RAL primary and recurrent PEH repairs from 2009 to 2017 at a single institution were reviewed. Demographics, use of mesh, estimated blood loss, intra-operative complications, conversion rates, operative time, rates of esophageal/gastric injury, hospital length of stay, re-admission/re-operation rates, recurrence, dysphagia, gas bloat, and pre- and post-operative proton pump inhibitor (PPI) use were analyzed. Analysis was accomplished using Chi-square test/Fischer's exact test for categorical variables and the Mann-Whitney U test for continuous variables. RESULTS: There were 298 patients who underwent RAL PEH repairs (247 primary, 51 recurrent). They were followed for a median (interquartile range) of 120 (44, 470) days. There were no significant differences in baseline demographics between groups. Patients in the recurrent PEH group had longer operative times, increased use of mesh, and increased length of hospital stay. They were also less likely to undergo fundoplication. There were no significant differences in estimated blood loss, incidence of intra-operative complications, re-admission rates, incidence of post-operative dysphagia and gas bloat, and incidence of post-operative PPI use. There were no conversions to open operative intervention or gastric/esophageal injury/leaks. CONCLUSIONS: Although repair of recurrent PEHs are historically associated with worse outcomes, in this series, RAL recurrent PEH repairs have similar peri-operative and post-operative outcomes as compared to primary PEH repairs. Whether this is secondary to the potential advantages afforded by the robotic platform deserves further study.

Correction to: Trocar site closure with a novel anchor-based (neoClose®) system versus standard suture closure: a prospective randomized controlled trial.

After careful review, the authors have noticed the following mistakes in the article entitled "Trocar site closure with a novel anchor based (neoClose®) system versus standard suture closure: A prospective randomized controlled trial": - Correct closure times are 19.9 seconds (SD 9.9) for the study group and 31.0 seconds (SD 20.1) for the control group (initial incorrect values were 20.2 seconds (SD 10.1) and 30 seconds (SD 19.1) respectively). The new correct P-value is <0.0001 (initial incorrect P-value was 0.0002). - Correct maximal needle depth values are 3.2 cm (SD 0.93) for the study group and 4.9 cm (SD 1.97) for the control group (initial incorrect values were 3.3 cm (SD 0.9) and 5.2 cm (SD 1.6) respectively). P-value remains unchanged at <0.0001. For these two outcomes, some values of control group patients were mistakenly included in the study group. These errors only marginally affected the mean and standard deviation values. Statistical significance of the results was not affected and the conclusions of the study remain unchanged.

The financial value of vascular surgeons as operative consultants to other surgical specialties.

OBJECTIVE: Vascular surgeons provide assistance to other surgical specialties through planned and unplanned joint operative cases. The financial impact to the hospital of vascular surgeons as consultants in this context has yet to be quantified. We sought to quantify the financial value of services provided by consulting vascular surgeons in the performance of joint operative procedures, both planned and unplanned. METHODS: Hospital financial data were reviewed for all inpatient operative cases during a 3-year period (2013-2015). Cases in which a vascular surgeon provided operative assistance as a consultant to a nonvascular surgeon were identified and designated planned or unplanned. Contribution margin, defined as hospital revenue minus variable cost, was determined for each case. In addition, the contribution margin ratio (contribution margin divided by revenue) was determined for each cohort. Financial data for consulting cases was compared with all nonconsult cases. Data analysis was performed with nonparametric statistics. RESULTS: There were 208 cases with a primary nonvascular surgeon that required a vascular co-surgeon during the study period, 169 planned and 39 unplanned. For comparison, 19,594 nonconsult cases of other surgical specialties were identified. The median contribution margin was higher for vascular surgery consult cases compared with nonconsult cases ($14,406 [interquartile range, $63,192] vs $5491 [interquartile range $28,590]; P = .002). The overall contribution margin ratio was higher for vascular surgery consult cases (0.41) compared with control nonconsult cases (0.35). There was no difference in contribution margin and contribution margin ratio between planned and unplanned vascular surgery consult cases. CONCLUSIONS: Vascular surgeons provide essential operative assistance to other surgical specialties. This operative assistance is frequent and provides significant financial value, with high contribution margin and contribution margin ratio. Vascular surgeons, as consulting surgeons, enable the completion of highly complex cases and in this capacity provide significant financial value to the hospital.

A distinct biomolecular profile identifies monoclonal mast cell disorders in patients with idiopathic anaphylaxis.

BACKGROUND: Clonal mast cell disorders are known to occur in a subset of patients with systemic reactions to Hymenoptera stings. This observation has prompted the question of whether clonal mast cell disorders also occur in patients with idiopathic anaphylaxis (IA). OBJECTIVE: We sought to determine the prevalence of clonal mast cell disorders among patients with IA, criteria to identify those patients who require a bone marrow biopsy, and whether the pathogenesis of IA involves a hyperresponsive mast cell compartment. METHODS: We prospectively enrolled patients with IA (≥3 episodes/y) who then underwent a medical evaluation that included a serum tryptase determination, allele-specific quantitative PCR (ASqPCR) for the KIT D816V mutation, and a bone marrow examination. Mast cells were cultured from peripheral blood CD34+ cells and examined for releasability after FcεRI aggregation. RESULTS: Clonal mast cell disease was diagnosed in 14% of patients referred with IA. ASqPCR for the KIT D816V mutation was a useful adjunct in helping identify those with systemic mastocytosis but not monoclonal mast cell activation syndrome. A modified overall clonal prediction model was developed by using clinical findings, a serum tryptase determination, and ASqPCR. There was no evidence of a hyperresponsive mast cell phenotype in patients with IA. CONCLUSION: Patients with clonal mast cell disease can present as having IA. Distinct clinical and laboratory features can be used to select those patients more likely to have an underlying clonal mast cell disorder (monoclonal mast cell activation syndrome or systemic mastocytosis) and thus candidates for a bone marrow biopsy.

Transoral outlet reduction with full thickness endoscopic suturing for weight regain after gastric bypass: a large multicenter international experience and meta-analysis.

BACKGROUND AND AIMS: Many patients who undergo bariatric surgery will experience weight regain and effective strategies are needed to help these patients. A dilated gastrojejunal anastomosis (GJA) has been associated with weight recidivism after Roux-en-Y gastric bypass surgery (RYGB). Endoscopic transoral outlet reduction (TORe) with a full thickness endoscopic suturing device (Overstitch, Apollo Endosurgery, Austin, TX) is a minimally invasive therapeutic option. The primary aim of this project was to examine the safety and long-term efficacy data from three bariatric surgery centers and to conduct a systematic review and meta-analysis of the existing literature. METHODS: Patients who underwent TORe with the Overstitch device from Jan 2013 to Nov 2016 at 3 participating bariatric surgery centers were included in the multicenter analysis. For the systematic review and meta-analysis, a comprehensive search of multiple English databases was conducted. Random effects model was used. RESULTS: 130 consecutive patients across three centers underwent TORe with an endolumenal suturing device. These patients (mean age 47; mean BMI 36.8) had experienced 24.6% weight regain from nadir weight after RYGB. Average weight lost at 6, 12, and 18 months after TORe was 9.31 ± 6.7 kg (N = 84), 7.75 ± 8.4  kg (N = 70), 8 ± 8.8 kg (N = 46) (p < 0.01 for all three time points), respectively. The meta-analysis included 330 patients. The pooled weight lost at 12 months was 8.4 kg (95% CI 6.5-10.3) with no significant heterogeneity across included studies (p = 0.07). Overall, 14% of patients experienced nausea, 18% had pain and 8% required a repeat EGD. No serious adverse events reported. CONCLUSION: When implemented as part of a multidisciplinary intervention, TORe using endolumenal suturing is safe, reproducible, and effective approach to manage weight recidivism after RYGB and should be utilized early in the management algorithm of these patients.

Clinical prediction rule to determine the need for repeat ERCP after endoscopic treatment of postsurgical bile leaks.

BACKGROUND AND AIMS: In patients who have undergone ERCP with biliary stenting for postsurgical bile leaks, the optimal method (ERCP or gastroscopy) and timing of stent removal is controversial. We developed a clinical prediction rule to identify cases in which a repeat ERCP is unnecessary. METHODS: Population-based study of all patients who underwent ERCP for management of surgically induced bile leaks between 2000 and 2012. Multivariate and binary recursive partitioning analyses were performed to generate a rule predicting the absence of biliary pathology on repeat endoscopic evaluation. RESULTS: A total of 259 patients were included. On multivariate analysis, postsurgical normal alkaline phosphatase (ALP; OR, 2.26; 95% CI, 1.03-4.99), time from surgery to first ERCP < 8 days (OR, 2.47; 95% CI, 1.15-5.31), and minor leak with no other pathology on initial ERCP (OR, 6.74; 95% CI, 1.75-25.89) were independently associated with the absence of persistent bile leak and other pathology on repeat ERCP. The derived rule included laparoscopic cholecystectomy, normal postsurgical ALP, minor leak with no other pathology on initial ERCP, and an interval from initial to repeat ERCP between 4 and 8 weeks. When all 4 criteria were met, the rule had a sensitivity of 94% (95% CI, 83%-99%) and a negative predictive value of 93% (95% CI, 81%-99%). Optimism-adjusted sensitivity and negative predictive value were 88% (95% CI, 76%-96%) and 86% (95% CI, 73%-96%), respectively. CONCLUSIONS: This clinical decision rule identifies patients who can have their biliary stents removed via gastroscopy, which may improve patient safety and healthcare utilization.

Patient perspectives on engagement in decision-making in early management of non-ST elevation acute coronary syndrome: a qualitative study.

BACKGROUND: Surveys of patients suggest many want to be actively involved in treatment decisions for acute coronary syndromes. However, patient experiences of their engagement and participation in early phase decision-making have not been well described. METHODS: We performed a patient led qualitative study to explore patient experiences with decision-making processes when admitted to hospital with non-ST elevation acute coronary syndrome. Trained patient-researchers conducted the study via a three-phase approach using focus groups and semi-structured interviews and employing grounded theory methodology. RESULTS: Twenty patients discharged within one year of a non-ST elevation acute coronary syndrome participated in the study. Several common themes emerged. First, patients characterized the admission and early treatment of ACS as a rapidly unfolding process where they had little control. Participants felt they played a passive role in early phase decision-making. Furthermore, participants described feeling reduced capacity for decision-making owing to fear and mental stress from acute illness, and therefore most but not all participants were relieved that expert clinicians made decisions for them. Finally, once past the emergent phase of care, participants wanted to retake a more active role in their treatment and follow-up plans. CONCLUSIONS: Patients admitted with ACS often do not take an active role in initial clinical decisions, and are satisfied to allow the medical team to direct early phase care. These results provide important insight relevant to designing patient-centered interventions in ACS and other urgent care situations.

Risk prediction models for acute kidney injury following major noncardiac surgery: systematic review.

BACKGROUND: Acute kidney injury (AKI) is a serious complication of major noncardiac surgery. Risk prediction models for AKI following noncardiac surgery may be useful for identifying high-risk patients to target with prevention strategies. METHODS: We conducted a systematic review of risk prediction models for AKI following major noncardiac surgery. MEDLINE, EMBASE, BIOSIS Previews and Web of Science were searched for articles that (i) developed or validated a prediction model for AKI following major noncardiac surgery or (ii) assessed the impact of a model for predicting AKI following major noncardiac surgery that has been implemented in a clinical setting. RESULTS: We identified seven models from six articles that described a risk prediction model for AKI following major noncardiac surgeries. Three studies developed prediction models for AKI requiring renal replacement therapy following liver transplantation, three derived prediction models for AKI based on the Risk, Injury, Failure, Loss of kidney function, End-stage kidney disease (RIFLE) criteria following liver resection and one study developed a prediction model for AKI following major noncardiac surgical procedures. The final models included between 4 and 11 independent variables, and c-statistics ranged from 0.79 to 0.90. None of the models were externally validated. CONCLUSIONS: Risk prediction models for AKI after major noncardiac surgery are available; however, these models lack validation, studies of clinical implementation and impact analyses. Further research is needed to develop, validate and study the clinical impact of such models before broad clinical uptake.

Prognostic implications of adding urine output to serum creatinine measurements for staging of acute kidney injury after major surgery: a cohort study.

BACKGROUND: Current guidelines recommend staging acute kidney injury (AKI) according to the serum creatinine (SCr) or urine output (UO) criteria that achieve the highest stage. There is little information about the implications of adding UO to SCr measurements for staging AKI outside intensive care units and after cardiac surgery. METHODS: We performed a cohort study of all adults without end-stage renal disease who underwent major noncardiac surgery between January 2005 and March 2011 in Calgary, AB, Canada. Participants required at least two SCr and UO measurements to be included. We examined the implications of adding UO to SCr to stage AKI based on Kidney Disease: Improving Global Outcomes criteria. Logistic and linear regression models were used to examine the associations between AKI stage and 30-day mortality or hospital length of stay (LOS), respectively. RESULTS: A total of 4229 (17%) surgical patients had sufficient SCr and UO measurements for inclusion in the cohort. The apparent incidence of postoperative AKI substantially increased with the addition of UO to SCr criteria (8.1% with SCr alone versus 64.0% with SCr and UO). Mortality for a given stage of AKI was lower when UO was added to SCr criteria (0.3, 3.2, 1.9 and 3.0% for no AKI and Stages 1, 2 and 3, respectively) versus with SCr alone (1.2, 4.2, 15.4 and 12.8%). However, among participants without AKI based on the SCr criterion, the odds of mortality and mean LOS both significantly increased with lower UO. Models that reclassified AKI stage based on UO in addition SCr criteria had the best discrimination for mortality and LOS. CONCLUSIONS: Adding UO to SCr criteria substantially increases the apparent incidence of AKI on hospital wards and significantly changes the prognostic implications of AKI identification and staging. These measures should not be considered equivalent criteria in AKI staging.

Kaplan-Meier Survival Analysis Overestimates the Risk of Revision Arthroplasty: A Meta-analysis.

BACKGROUND: Although Kaplan-Meier survival analysis is commonly used to estimate the cumulative incidence of revision after joint arthroplasty, it theoretically overestimates the risk of revision in the presence of competing risks (such as death). Because the magnitude of overestimation is not well documented, the potential associated impact on clinical and policy decision-making remains unknown. QUESTIONS/PURPOSES: We performed a meta-analysis to answer the following questions: (1) To what extent does the Kaplan-Meier method overestimate the cumulative incidence of revision after joint replacement compared with alternative competing-risks methods? (2) Is the extent of overestimation influenced by followup time or rate of competing risks? METHODS: We searched Ovid MEDLINE, EMBASE, BIOSIS Previews, and Web of Science (1946, 1980, 1980, and 1899, respectively, to October 26, 2013) and included article bibliographies for studies comparing estimated cumulative incidence of revision after hip or knee arthroplasty obtained using both Kaplan-Meier and competing-risks methods. We excluded conference abstracts, unpublished studies, or studies using simulated data sets. Two reviewers independently extracted data and evaluated the quality of reporting of the included studies. Among 1160 abstracts identified, six studies were included in our meta-analysis. The principal reason for the steep attrition (1160 to six) was that the initial search was for studies in any clinical area that compared the cumulative incidence estimated using the Kaplan-Meier versus competing-risks methods for any event (not just the cumulative incidence of hip or knee revision); we did this to minimize the likelihood of missing any relevant studies. We calculated risk ratios (RRs) comparing the cumulative incidence estimated using the Kaplan-Meier method with the competing-risks method for each study and used DerSimonian and Laird random effects models to pool these RRs. Heterogeneity was explored using stratified meta-analyses and metaregression. RESULTS: The pooled cumulative incidence of revision after hip or knee arthroplasty obtained using the Kaplan-Meier method was 1.55 times higher (95% confidence interval, 1.43-1.68; p < 0.001) than that obtained using the competing-risks method. Longer followup times and higher proportions of competing risks were not associated with increases in the amount of overestimation of revision risk by the Kaplan-Meier method (all p > 0.10). This may be due to the small number of studies that met the inclusion criteria and conservative variance approximation. CONCLUSIONS: The Kaplan-Meier method overestimates risk of revision after hip or knee arthroplasty in populations where competing risks (such as death) might preclude the occurrence of the event of interest (revision). Competing-risks methods should be used to more accurately estimate the cumulative incidence of revision when the goal is to plan healthcare services and resource allocation for revisions.

Mastocytosis associated with a rare germline KIT K509I mutation displays a well-differentiated mast cell phenotype.

BACKGROUND: Mastocytosis associated with germline KIT activating mutations is exceedingly rare. We report the unique clinicopathologic features of a patient with systemic mastocytosis caused by a de novo germline KIT K509I mutation. OBJECTIVES: We sought to investigate the effect of the germline KIT K509I mutation on human mast cell development and function. METHODS: Primary human mast cells derived from CD34(+) peripheral blood progenitors were examined for growth, development, survival, and IgE-mediated activation. In addition, a mast cell transduction system that stably expressed the KIT K509I mutation was established. RESULTS: KIT K509I biopsied mast cells were round, CD25(-), and well differentiated. KIT K509I progenitors cultured in stem cell factor (SCF) demonstrated a 10-fold expansion compared with progenitors from healthy subjects and developed into mature hypergranular mast cells with enhanced antigen-mediated degranulation. KIT K509I progenitors cultured in the absence of SCF survived but lacked expansion and developed into hypogranular mast cells. A KIT K509I mast cell transduction system revealed SCF-independent survival to be reliant on the preferential splicing of KIT at the adjacent exonic junction. CONCLUSION: Germline KIT mutations associated with mastocytosis drive a well-differentiated mast cell phenotype distinct to that of somatic KIT D816V disease, the oncogenic potential of which might be influenced by SCF and selective KIT splicing.

Restoration of riparian areas following the removal of cattle in the northwestern great basin.

We assessed the effects of the elimination of livestock in riparian systems at Hart Mountain National Antelope Refuge in southeastern Oregon, 23 years after the removal of cattle grazing, using 64 photos taken before grazing was removed compared with later retake photos. Two methods were used for this assessment: (1) a qualitative visual method comparing seven cover types and processes and (2) a new quantitative method of inserting digital line transects into photos. Results indicated that channel widths and eroding banks decreased in 64 and 73% of sites, respectively. We found a 90% decrease in the amount of bare soil (P < 0.001) and a 63% decrease in exposed channel (P < 0.001) as well as a significant increase in the cover of grasses/sedges/forbs (15% increase, P = 0.037), rushes (389% increase, P = 0.014), and willow (388% increase, P < 0.001). We also assessed the accuracy of the new method of inserting digital line transects into photo pairs. An overall accuracy of 91% (kappa 83%) suggests that digital line transects can be a useful tool for quantifying vegetation cover from photos. Our results indicate that the removal of cattle can result in dramatic changes in riparian vegetation, even in semi-arid landscapes and without replanting or other active restoration efforts.

Evaluation of basic life support interventions for foreign body airway obstructions: A population-based cohort study.

AIM: To quantify the associations of foreign body airway obstruction (FBAO) basic life support (BLS) interventions with FBAO relief and survival to discharge. METHODS: We identified prehospital FBAO patient encounters in Alberta, Canada between Jan 1, 2018 and Dec 31,2021 using the provincial emergency medical services' medical records, deterministically linked to hospital data. Two physicians reviewed encounters to determine cases and extract data. Multivariable logistic regression determined the adjusted odds ratio of FBAO relief (primary outcome) and survival to discharge for the exposure of BLS interventions (abdominal thrusts [AT], chest compressions/thrusts [CC], or combinations) relative to back blows [BB]. Intervention-associated injuries were identified using International Classification of Diseases codes, followed by health records review. RESULTS: We identified 3,677 patient encounters, including 709 FBAOs requiring intervention. Bystanders performed the initial BLS intervention in 488 cases (77.4%). Bystanders and paramedics did not relieve the FBAO in 151 (23.5%) and 11 (16.7%) cases, respectively. FBAOs not relieved before paramedic arrival had a higher proportion of deaths (n = 4[0.4%] versus n = 92[42.4%], p < 0.001). AT and CC were associated with decreased odds of FBAO relief relative to BB (adjusted odds ratio [aOR] 0.49 [95%CI 0.30-0.80] and 0.14 [95%CI 0.07-0.28], respectively). CC were associated with decreased odds of survival to discharge (aOR 0.04 [95%CI 0.01-0.32]). AT, CC, and BB were implicated in intervention-associated injuries in four, nine, and zero cases, respectively. CONCLUSIONS: Back blows are associated with improved outcomes compared to abdominal thrusts and chest compressions. These data can inform prospective studies aimed at improving response to choking emergencies.