Perioperative Complications Associated with Severity of Anemia in Geriatric Patients Undergoing Spinal Procedures.

OBJECTIVE: To investigate preoperative baseline anemia, stratified by severity as a function of hematocrit level, as a risk factor for perioperative complications in geriatric patients undergoing spinal procedures. BACKGROUND: Previous literature has examined the impact of anemia on risk for complications and adverse outcomes in patients undergoing elective spinal procedures. However, there is a paucity of literature analyzing the impact of anemia in the geriatric population, specifically. METHODS: The American College of Surgeons-National Surgical Quality Improvement Database was used to identify patients older than 65 years who had undergone elective spinal procedures and were subsequently stratified into 3 separate cohorts based on hematocrit levels: severe/moderate (hematocrit level <30%), mild (30%-37%), and no anemia (>38%). These patient samples were then analyzed using multivariate analyses to assess severity of anemia as a risk factor for complications in elderly patients undergoing spinal procedures. RESULTS: When anemia classes were analyzed as separate independent risk factors for complications, mild anemia (class II) was a significant risk factor for the same complications as moderate/severe anemia (class III/IV), with the exception of 2 complications, compared with nonanemic patients. Mild anemia was independently associated with wound dehiscence (odds ratio, 1.521; 95% confidence interval, 1.126-2.054; P = 0.006), whereas moderate/severe anemia did not show an increased risk for wound dehiscence. However, moderate/severe anemia independently increased the risk for deep venous thromboembolism (odds ratio, 1.437; 95% confidence interval, 1.028-2.011; P = 0.034), compared with mild anemia. Both categories of anemia independently increased the risk for additional complications such as deep incisional surgical site infection, organ/space surgical site infection, pneumonia, unplanned intubation, ventilator dependence, progressive renal insufficiency, acute renal failure, urinary tract infections, cardiac arrest, myocardial infarctions, blood transfusions, systemic sepsis, reoperation, extended length of stay of ≥5 days, unplanned readmission, and mortality. CONCLUSIONS: This study indicated that patients with preoperative baseline anemia were at risk for requiring transfusions, renal failure, and infectious complications. Physicians should be cognizant of anemia as a risk factor affecting numerous perioperative complications and adverse outcomes to work toward improving health-related quality of life.

A screen for F1 hybrid male rescue reveals no major-effect hybrid lethality loci in the Drosophila melanogaster autosomal genome.

Hybrid sons between Drosophila melanogaster females and D. simulans males die as 3rd instar larvae. Two genes, D. melanogaster Hybrid male rescue (Hmr) on the X chromosome, and D. simulans Lethal hybrid rescue (Lhr) on chromosome II, interact to cause this lethality. Loss-of-function mutations in either gene suppress lethality, but several pieces of evidence suggest that additional factors are required for hybrid lethality. Here we screen the D. melanogaster autosomal genome by using the Bloomington Stock Center Deficiency kit to search for additional regions that can rescue hybrid male lethality. Our screen is designed to identify putative hybrid incompatibility (HI) genes similar to Hmr and Lhr which, when removed, are dominant suppressors of lethality. After screening 89% of the autosomal genome, we found no regions that rescue males to the adult stage. We did, however, identify several regions that rescue up to 13% of males to the pharate adult stage. This weak rescue suggests the presence of multiple minor-effect HI loci, but we were unable to map these loci to high resolution, presumably because weak rescue can be masked by genetic background effects. We attempted to test one candidate, the dosage compensation gene male specific lethal-3 (msl-3), by using RNA interference with short hairpin microRNA constructs targeted specifically against D. simulans msl-3 but failed to achieve knockdown, in part due to off-target effects. We conclude that the D. melanogaster autosomal genome likely does not contain additional major-effect HI loci. We also show that Hmr is insufficient to fully account for the lethality associated with the D. melanogaster X chromosome, suggesting that additional X-linked genes contribute to hybrid lethality.