Chow, Jonathan H.

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: Patients supported on mechanical circulatory support devices experience vasodilatory hypotension due to high surface area exposure to nonbiological and non-endothelialized surfaces. Angiotensin II has been studied in general settings of vasodilatory shock, however concerns exist regarding the use of this vasopressor in patients with pre-existing cardiac failure. The objective of this study was to assess the systemic and central hemodynamic effects of angiotensin II in patients with primary cardiac or respiratory failure requiring treatment with mechanical circulatory support devices. Methods: Multicenter retrospective observational study of adults supported on a mechanical circulatory support device who received angiotensin II for vasodilatory shock. The primary outcome was the intraindividual change from baseline in mean arterial pressure (MAP) and vasopressor dosage after angiotensin II. Results: Fifty patients were included with mechanical circulatory devices that were primarily used for cardiac failure (n = 41) or respiratory failure (n = 9). At angiotensin II initiation, the norepinephrine equivalent vasopressor dosage was 0.44 (0.34, 0.64) and 0.47 (0.33, 0.73) mcg/kg/min in the cardiac and respiratory groups, respectively. In the cardiac group, MAP increased from 60 to 70 mmHg (intraindividual P < .001) in the 1 h after angiotensin II initiation and the vasopressor dosage declined by 0.04 mcg/kg/min (intraindividual P < .001). By 12 h, the vasopressor dosage declined by 0.16 mcg/kg/min ( P = .001). There were no significant changes in cardiac index or mean pulmonary artery pressure throughout the 12 h following angiotensin II. In the respiratory group, similar but nonsignificant effects at 1 h on MAP (61-81 mmHg, P = .26) and vasopressor dosage (decline by 0.13 mcg/kg/min, P = .06) were observed. Conclusions: In patients requiring mechanical circulatory support for cardiac failure, angiotensin II produced beneficial systemic hemodynamic effects without negatively impacting cardiac function or pulmonary pressures. The systemic hemodynamic effects in those with respiratory failure were nonsignificant due to limited sample size.

Background Coronavirus disease 2019 (COVID-19) is associated with a prothrombotic state; leading to multiple sequelae. We sought to detect whether thromboelastography (TEG) parameters would be able to detect thromboembolic events in patients hospitalized with COVID-19. Methods We performed a retrospective multicenter case–control study of the Collaborative Research to Understand the Sequelae of Harm in COVID (CRUSH COVID) registry of 8 tertiary care level hospitals in the United States (US). This registry contains adult patients with COVID-19 hospitalized between March 2020 and September 2020. Results A total of 277 hospitalized COVID-19 patients were analyzed to determine whether conventional coagulation TEG parameters were associated with venous thromboembolic (VTE) and thrombotic events during hospitalization. A clotting index (CI) >3 was present in 45.8% of the population, consistent with a hypercoagulable state. Eighty-three percent of the patients had clot lysis at 30 min (LY30) = 0, consistent with fibrinolysis shutdown, with a median of 0.1%. We did not find TEG parameters (LY30 area under the receiver operating characteristic [ROC] curve [AUC] = 0.55, 95% CI: 0.44-0.65, P value = .32; alpha angle [α] AUC = 0.58, 95% CI: 0.47-0.69, P value = .17; K time AUC = 0.58, 95% CI: 0.46-0.69, P value = .67; maximum amplitude (MA) AUC = 0.54, 95% CI: 0.44-0.64, P value = .47; reaction time [R time] AUC = 0.53, 95% CI: 0.42-0.65, P value = .70) to be a good discriminator for VTE. We also did not find TEG parameters (LY30 AUC = 0.51, 95% CI: 0.42-0.60, P value = .84; R time AUC = 0.57, 95%CI: 0.48-0.67, P value .07; α AUC = 0.59, 95%CI: 0.51-0.68, P value = .02; K time AUC = 0.62, 95% CI: 0.53-0.70, P value = .07; MA AUC = 0.65, 95% CI: 0.57-0.74, P value < .01) to be a good discriminator for thrombotic events. Conclusions In this retrospective multicenter cohort study, TEG in COVID-19 hospitalized patients may indicate a hypercoagulable state, however, its use in detecting VTE or thrombotic events is limited in this population.

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.

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.