Background Despite the significant healthcare impact of acute kidney injury, little is known regarding prevention. Single-center data have implicated hypotension in developing postoperative acute kidney injury. The generalizability of this finding and the interaction between hypotension and baseline patient disease burden remain unknown. The authors sought to determine whether the association between intraoperative hypotension and acute kidney injury varies by preoperative risk. Methods Major noncardiac surgical procedures performed on adult patients across eight hospitals between 2008 and 2015 were reviewed. Derivation and validation cohorts were used, and cases were stratified into preoperative risk quartiles based upon comorbidities and surgical procedure. After preoperative risk stratification, associations between intraoperative hypotension and acute kidney injury were analyzed. Hypotension was defined as the lowest mean arterial pressure range achieved for more than 10 min; ranges were defined as absolute (mmHg) or relative (percentage of decrease from baseline). Results Among 138,021 cases reviewed, 12,431 (9.0%) developed postoperative acute kidney injury. Major risk factors included anemia, estimated glomerular filtration rate, surgery type, American Society of Anesthesiologists Physical Status, and expected anesthesia duration. Using such factors and others for risk stratification, patients with low baseline risk demonstrated no associations between intraoperative hypotension and acute kidney injury. Patients with medium risk demonstrated associations between severe-range intraoperative hypotension (mean arterial pressure less than 50 mmHg) and acute kidney injury (adjusted odds ratio, 2.62; 95% CI, 1.65 to 4.16 in validation cohort). In patients with the highest risk, mild hypotension ranges (mean arterial pressure 55 to 59 mmHg) were associated with acute kidney injury (adjusted odds ratio, 1.34; 95% CI, 1.16 to 1.56). Compared with absolute hypotension, relative hypotension demonstrated weak associations with acute kidney injury not replicable in the validation cohort. Conclusions Adult patients undergoing noncardiac surgery demonstrate varying associations with distinct levels of hypotension when stratified by preoperative risk factors. Specific levels of absolute hypotension, but not relative hypotension, are an important independent risk factor for acute kidney injury. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

This paper discusses the application of the theory of partially observable Markov decision processes (POMDPs) to the design of guidance algorithms for controlling the motion of unmanned aerial vehicles (UAVs) with onboard sensors to improve tracking of multiple ground targets. While POMDP problems are intractable to solve exactly, principled approximation methods can be devised based on the theory that characterizes optimal solutions. A new approximation method called nominal belief-state optimization (NBO), combined with other application-specific approximations and techniques within the POMDP framework, produces a practical design that coordinates the UAVs to achieve good long-term mean-squared-error tracking performance in the presence of occlusions and dynamic constraints. The flexibility of the design is demonstrated by extending the objective to reduce the probability of a track swap in ambiguous situations.

IntroductionThe prevalence of childhood asthma in the United States increased from 8.7% in 2001 to 9.5% in 2011. This increased prevalence adds to the costs incurred by state Medicaid programs. We provide state-based cost estimates of pediatric asthma emergency department (ED) visits and highlight an opportunity for states to reduce these costs through a recently changed Centers for Medicare and Medicaid Services (CMS) regulation.MethodsWe used a cross-sectional design across multiple data sets to produce state-based cost estimates for asthma-related ED visits among children younger than 18, where Medicaid/CHIP (Children’s Health Insurance Program) was the primary payer.ResultsThere were approximately 629,000 ED visits for pediatric asthma for Medicaid/CHIP enrollees, which cost $272 million in 2010. The average cost per visit was $433. Costs ranged from $282,000 in Alaska to more than $25 million in California.ConclusionsCosts to states for pediatric asthma ED visits vary widely. Effective January 1, 2014, the CMS rule expanded which type of providers can be reimbursed for providing preventive services to Medicaid/CHIP beneficiaries. This rule change, in combination with existing flexibility for states to define practice setting, allows state Medicaid programs to reimburse for asthma interventions that use nontraditional providers (such as community health workers or certified asthma educators) in a nonclinical setting, as long as the service was initially recommended by a physician or other licensed practitioner. The rule change may help states reduce Medicaid costs of asthma treatment and the severity of pediatric asthma.

No abstract

This paper studies Newton-type methods for minimization of partly smooth convex functions. Sequential Newton methods are provided using local parameterizations obtained from U-Lagrangian theory and from Riemannian geometry. The Hessian based on the U-Lagrangian depends on the selection of a dual parameter g; by revealing the connection to Riemannian geometry, a natural choice of g emerges for which the two Newton directions coincide. This choice of g is also shown to be related to the least-squares multiplier estimate from a sequential quadratic programming (SQP) approach, and with this multiplier, SQP gives the same search direction as the Newton methods.