Mazzeffi, Michael

Introduction High-dose catecholamines can impair hypoxic pulmonary vasoconstriction and increase shunt fraction. We aimed to determine if Angiotensin II (Ang-2) is associated with improved PaO 2 /FiO 2 and SpO 2 /FiO 2 in patients in shock. Methods Adult patients at four tertiary care centers and one community hospital in the United States who received Ang-2 from July 2018-September 2020 were included in this retrospective, observational cohort study. PaO 2 , SpO 2 , and FiO 2 were measured at 13 timepoints during the 48-h before and after Ang-2 initiation. Piecewise linear mixed models of PaO 2 /FiO 2 and SpO 2 /FiO 2 were created to evaluate hourly changes in oxygenation after Ang-2 initiation. The difference in the proportion of patients with PaO 2 /FiO 2 ≤ 300 mm Hg at the time of Ang-2 initiation and 48 h after was also examined. Results The study included 254 patients. In the 48 h prior to Ang-2 initiation, oxygenation was significantly declining (hourly PaO 2 /FiO 2 change −4.7 mm Hg/hr, 95% CI − 6.0 to −3.5, p < .001; hourly SpO 2 /FiO 2 change −3.1/hr, 95% CI−3.7 to −2.4, p < .001). Ang-2 treatment was associated with significant improvements in PaO 2 /FiO 2 and SpO 2 /FiO 2 in the 48-h after initiation (hourly PaO 2 /FiO 2 change +1.5 mm Hg/hr, 95% CI 0.5-2.5, p = .003; hourly SpO 2 /FiO 2 change +0.9/hr, 95% CI 0.5-1.2, p < .001). The difference in the hourly change in oxygenation before and after Ang-2 initiation was also significant ( p interaction < 0.001 for both PaO 2 /FiO 2 and SpO 2 /FiO 2 ). This improvement was associated with significantly fewer patients having a PaO 2 /FiO 2 ≤ 300 mm Hg at 48 h compared to baseline (mean difference −14.9%, 95% CI −25.3% to −4.6%, p = .011). Subgroup analysis found that patients with either a baseline PaO 2 /FiO 2 ≤ 300 mm Hg or a norepinephrine-equivalent dose requirement >0.2 µg/kg/min had the greatest associations with oxygenation improvement. Conclusions Ang-2 is associated with improved PaO 2 /FiO 2 and SpO 2 /FiO 2 . The mechanisms for this improvement are not entirely clear but may be due to catecholamine-sparing effect or may also be related to improved ventilation-perfusion matching, intrapulmonary shunt, or oxygen delivery.

BACKGROUND: Peripheral nerve blocks (PNBs) are used to provide postoperative analgesia after total mastectomy. PNBs improve patient satisfaction and decrease postoperative opioid use, nausea, and vomiting. Few studies have examined whether there is racial-ethnic disparity in the use of PNBs for patients having total mastectomy. We hypothesized that non-Hispanic Asian, non-Hispanic Black, non-Hispanic patients of other races, and Hispanic patients would be less likely to receive a PNB for postoperative analgesia compared to non-Hispanic White patients having total mastectomy. Secondarily, we hypothesized that PNBs would be associated with reduced odds of major complications after total mastectomy. METHODS: We performed a retrospective cohort study using National Surgical Quality Improvement Program (NSQIP) data from 2015 to 2019. Patients were included if they underwent total mastectomy under general anesthesia. Unadjusted rates of PNB use were compared between race-ethnicity groups. Multivariable logistic regression was performed to determine whether race-ethnicity group was independently associated with receipt of a PNB for postoperative analgesia. Secondarily, we calculated crude and risk-adjusted odds ratios for major complications in patients who received a PNB. RESULTS: There were 64,103 patients who underwent total mastectomy and 4704 (7.3%) received a PNB for postoperative analgesia. Patients who received a PNB were younger, more commonly women, were less likely to have diabetes and hypertension, and had less disseminated cancer (all P < .05). In our regression analysis, the odds of receiving a PNB differed significantly by race-ethnicity group ( P < .001). Non-Hispanic Asian and non-Hispanic Black patients had reduced odds of receiving a PNB compared to non-Hispanic White patients (odds ratio [OR], 0.41; 95% confidence interval [CI], 0.33–0.49 and OR, 0.37 [0.32–0.44]), respectively. Non-Hispanic patients of other races, including American Indian, Alaskan Native, and Pacific Islander, also had reduced odds of receiving a PNB (OR, 0.73 [95% CI, 0.64–0.84]) compared to non-Hispanic White patients, as did Hispanic patients (OR, 0.62 [0.56–0.69]). Patients who received a PNB did not have reduced odds of major complications after mastectomy (crude OR, 0.83 [0.65–1.08]; P = .17 and adjusted OR, 0.85 [0.65–1.10]; P = .21). CONCLUSIONS: Significant disparity exists in the use of PNBs for postoperative analgesia in patients of different race-ethnicity who undergo total mastectomy in the United States. Continued efforts are needed to better understand the causes of disparity and to ensure equitable access to PNBs.

Background. Patients having hip fracture surgery are at high risk for postoperative delirium. Red blood cell (RBC) transfusion may increase postoperative delirium risk by causing neuroinflammation. We hypothesized that RBC transfusion would be associated with postoperative delirium in patients having hip fracture surgery. Methods. An observational cohort study was performed using the United States National Surgical Quality Improvement Program (NSQIP) participant use files for hip fracture from 2016 to 2018. Propensity score analysis and inverse probability of treatment weighting (IPTW) were used to reduce bias from confounding. An IPTW adjusted odds ratio for developing postoperative delirium was calculated for patients who received RBC transfusion during surgery or in the 72 hours after. Results. There were 20,838 patients who had eligible current procedural terminology (CPT) codes for primary hip fracture surgery and complete study data. After employing strict exclusions to balance covariates and reduce bias, 3,715 patients remained in the IPTW cohort. Of these, 626 patients (16.9%) received RBC transfusion and 665 patients (17.9%) developed postoperative delirium. IPTW adjustment led to good covariate balance between patients who received RBC transfusion and those who did not. Patients who received RBC transfusion had significantly higher odds of postoperative delirium, IPTW adjusted odds ratio = 1.21, 95% CI = 1.03 to 1.43, andP = 0.02. Discharge location also differed significantly between patients who received RBC transfusion and those who did not (P < 0.001) with in-hospital mortality or referral to hospice occurring in 1.6% of patients who received RBC transfusion and 1.3% of patients who were not transfused. Conclusion. RBC transfusion is associated with increased odds of postoperative delirium after hip fracture surgery and may be associated with worse clinical outcome.

AbstractPurposeThe purpose of the study was to investigate factors associated with early discontinuation of low‐dose ketamine infusions due to adverse drug events (ADEs).MethodsA retrospective, matched case‐control study of surgical patients who received low‐dose ketamine infusions for postoperative pain over 6 years was conducted. Forty‐seven study patients, who required early discontinuation of their infusion due to ADEs, were included and matched 1:1 with 47 controls, who did not experience ADEs, for a total of 94 patients. The two groups were compared based on surgery type, American Society of Anesthesiologists (ASA) classification, administration of specific perioperative anxiolytic, anesthetic, and analgesic medications, and use of regional anesthesia.ResultsOf the study patients, 44.7% underwent spine procedures (vs. 34% of controls), 27.6% underwent abdominal procedures (vs. 8.5% of controls), 19.2% underwent orthopedic procedures (vs. 46.8% of controls), and 8.5% underwent thoracic procedures (vs. 6.4% of controls). There were no statistically significant differences in ASA classification, pre‐operative gabapentinoid and antidepressant use, average ketamine infusion dose, or postoperative use of peripheral nerve catheters, nonsteroidal anti‐inflammatory drugs (NSAIDs), acetaminophen, muscle relaxants, and nonbenzodiazepine sleep aides. Study patients had higher rates of intra‐operative volatile anesthetic use (78.7% vs. 57.7%, p = 0.03) and more postoperative opioid patient‐controlled analgesia (PCA) use (53.2% vs. 29.8%, p = 0.02) than controls. Control patients had higher rates of preoperative opioid use (76.7% vs. 53.2%, p = 0.02) and premedication with midazolam (89.4% vs. 70.2%, p = 0.02) than study patients.ConclusionPatients who required discontinuation of their low‐dose ketamine infusion due to ADEs were more likely to be opioid naïve, received less pre‐operative benzodiazepines, and had greater postoperative opioid PCA requirements. Control patients, on the other hand, had higher rates of pre‐operative opioid use and experienced fewer ADEs despite greater total ketamine doses.

AbstractBackgroundAnemia is associated with poor outcome after major joint replacement surgery, but it is unclear whether sex and race modify its impact on outcome. We hypothesized that anemia would be associated with increased morbidity or mortality after knee arthroplasty surgery and that sex and race would be effect modifiers for this relationship.Study Design and MethodsWe performed a retrospective cohort study of elective knee arthroplasty patients between 2013 and 2018 using data from the National Surgical Quality Improvement Program. Morbidity or mortality after surgery was compared between patients without anemia, with mild anemia, and with moderate to severe anemia. Multivariable logistic regression was used to determine adjusted odds for morbidity or mortality with anemia. Interaction terms were entered into the model to test for effect modification by sex and race.Results243 491 patients were included and 30 135 patients (12.4%) were anemic. Morbidity or mortality occurred in 3.7% of patients without anemia, 5.2% of patients with mild anemia, and 7.1% of patients with moderate to severe anemia (P < .001). After adjustment for confounding variables, mild anemia OR = 1.36 (95% CI = 1.28‐1.45), and moderate to severe anemia OR = 1.92 (95% CI = 1.72‐2.13) were associated with increased odds of morbidity or mortality. Sex, but not race, was a significant effect modifier with men having a greater increase in morbidity or mortality when anemic (P = .02).ConclusionsAnemia is associated with increased morbidity or mortality after knee arthroplasty surgery and men have a greater increase in perioperative risk than women when anemic.