Initiating angiotensin II at lower vasopressor doses in vasodilatory shock: an exploratory post-hoc analysis of the ATHOS-3 clinical trial.

BACKGROUND: High dose vasopressors portend poor outcome in vasodilatory shock. We aimed to evaluate the impact of baseline vasopressor dose on outcomes in patients treated with angiotensin II (AT II). METHODS: Exploratory post-hoc analysis of the Angiotensin II for the Treatment of High-Output Shock (ATHOS-3) trial data. The ATHOS-3 trial randomized 321 patients with vasodilatory shock, who remained hypotensive (mean arterial pressure of 55-70 mmHg) despite receiving standard of care vasopressor support at a norepinephrine-equivalent dose (NED) > 0.2 µg/kg/min, to receive AT II or placebo, both in addition to standard of care vasopressors. Patients were grouped into low (≤ 0.25 µg/kg/min; n = 104) or high (> 0.25 µg/kg/min; n = 217) NED at the time of study drug initiation. The primary outcome was the difference in 28-day survival between the AT II and placebo subgroups in those with a baseline NED ≤ 0.25 µg/kg/min at the time of study drug initiation. RESULTS: Of 321 patients, the median baseline NED in the low-NED subgroup was similar in the AT II (n = 56) and placebo (n = 48) groups (median of each arm 0.21 µg/kg/min, p = 0.45). In the high-NED subgroup, the median baseline NEDs were also similar (0.47 µg/kg/min AT II group, n = 107 vs. 0.45 µg/kg/min placebo group, n = 110, p = 0.75). After adjusting for severity of illness, those randomized to AT II in the low-NED subgroup were half as likely to die at 28-days compared to placebo (HR 0.509; 95% CI 0.274-0.945, p = 0.03). No differences in 28-day survival between AT II and placebo groups were found in the high-NED subgroup (HR 0.933; 95% CI 0.644-1.350, p = 0.71). Serious adverse events were less frequent in the low-NED AT II subgroup compared to the placebo low-NED subgroup, though differences were not statistically significant, and were comparable in the high-NED subgroups. CONCLUSIONS: This exploratory post-hoc analysis of phase 3 clinical trial data suggests a potential benefit of AT II introduction at lower doses of other vasopressor agents. These data may inform design of a prospective trial. TRIAL REGISTRATION: The ATHOS-3 trial was registered in the clinicaltrials.gov repository (no. NCT02338843). Registered 14 January 2015.

Norepinephrine versus phenylephrine for treating hypotension during general anaesthesia in adult patients undergoing major noncardiac surgery: a multicentre, open-label, cluster-randomised, crossover, feasibility, and pilot trial.

BACKGROUND: Intraoperative hypotension is associated with postoperative complications. The use of vasopressors is often required to correct hypotension but the best vasopressor is unknown. METHODS: A multicentre, cluster-randomised, crossover, feasibility and pilot trial was conducted across five hospitals in California. Phenylephrine (PE) vs norepinephrine (NE) infusion as the first-line vasopressor in patients under general anaesthesia alternated monthly at each hospital for 6 months. The primary endpoint was first-line vasopressor administration compliance of 80% or higher. Secondary endpoints were acute kidney injury (AKI), 30-day mortality, myocardial injury after noncardiac surgery (MINS), hospital length of stay, and rehospitalisation within 30 days. RESULTS: A total of 3626 patients were enrolled over 6 months; 1809 patients were randomised in the NE group, 1817 in the PE group. Overall, 88.2% received the assigned first-line vasopressor. No drug infiltrations requiring treatment were reported in either group. Patients were median 63 yr old, 50% female, and 58% white. Randomisation in the NE group vs PE group did not reduce readmission within 30 days (adjusted odds ratio=0.92; 95% confidence interval, 0.6-1.39), 30-day mortality (1.01; 0.48-2.09), AKI (1.1; 0.92-1.31), or MINS (1.63; 0.84-3.16). CONCLUSIONS: A large and diverse population undergoing major surgery under general anaesthesia was successfully enrolled and randomised to receive NE or PE infusion. This pilot and feasibility trial was not powered for adverse postoperative outcomes and a follow-up multicentre effectiveness trial is planned. CLINICAL TRIAL REGISTRATION: NCT04789330 (ClinicalTrials.gov).

Anticoagulation practices for continuous renal replacement therapy: a survey of physicians from the United States.

BACKGROUND: During continuous renal replacement therapy (CRRT), anticoagulants are recommended for patients at low risk of bleeding and not already receiving systemic anticoagulants. Current anticoagulants used in CRRT in the US are systemic heparins or regional citrate. To better understand use of anticoagulants for CRRT in the US, we surveyed nephrologists and critical care medicine (CCM) specialists. METHODS: The survey contained 30 questions. Respondents were board certified and worked in intensive care units of academic medical centers or community hospitals. RESULTS: 150 physicians (70 nephrologists and 80 CCM) completed the survey. Mean number of CRRT machines in use increased ∼30% from the pre-pandemic era to 2022. Unfractionated heparin was the most used anticoagulant (43% of estimated patients) followed by citrate (28%). Respondents reported 29% of patients received no anticoagulant. Risk of hypocalcemia (52%) and citrate safety (42%) were the predominant reasons given for using no anticoagulant instead of citrate in heparin-intolerant patients. 84% said filter clogging was a problem when no anticoagulant was used, and almost 25% said increased transfusions were necessary. Respondents using heparin (n = 131) considered it inexpensive and easily obtainable, although of moderate safety, citing concerns of heparin-induced thrombocytopenia and bleeding. Anticoagulant citrate dextrose solution was the most used citrate. Respondents estimated that 37% of patients receiving citrate develop hypocalcemia and 17% citrate lock. CONCLUSIONS: Given the increased use of CRRT and the lack of approved, safe, and effective anticoagulant choices for CRRT in the US, effective use of current and other anticoagulant options needs to be evaluated.

Renin and Survival in Patients Given Angiotensin II for Catecholamine-Resistant Vasodilatory Shock. A Clinical Trial.

Rationale: Exogenous angiotensin II increases mean arterial pressure in patients with catecholamine-resistant vasodilatory shock (CRVS). We hypothesized that renin concentrations may identify patients most likely to benefit from such therapy.Objectives: To test the kinetic changes in renin concentrations and their prognostic value in patients with CRVS.Methods: We analyzed serum samples from patients enrolled in the ATHOS-3 (Angiotensin II for the Treatment of High-Output Shock) trial for renin, angiotensin I, and angiotensin II concentrations before the start of administration of angiotensin II or placebo and after 3 hours.Measurements and Main Results: Baseline serum renin concentration (normal range, 2.13-58.78 pg/ml) was above the upper limits of normal in 194 of 255 (76%) study patients with a median renin concentration of 172.7 pg/ml (interquartile range [IQR], 60.7 to 440.6 pg/ml), approximately threefold higher than the upper limit of normal. Renin concentrations correlated positively with angiotensin I/II ratios (r = 0.39; P < 0.001). At 3 hours after initiation of angiotensin II therapy, there was a 54.3% reduction (IQR, 37.9% to 66.5% reduction) in renin concentration compared with a 14.1% reduction (IQR, 37.6% reduction to 5.1% increase) with placebo (P < 0.0001). In patients with renin concentrations above the study population median, angiotensin II significantly reduced 28-day mortality to 28 of 55 (50.9%) patients compared with 51 of 73 patients (69.9%) treated with placebo (unstratified hazard ratio, 0.56; 95% confidence interval, 0.35 to 0.88; P = 0.012) (P = 0.048 for the interaction).Conclusions: The serum renin concentration is markedly elevated in CRVS and may identify patients for whom treatment with angiotensin II has a beneficial effect on clinical outcomes.Clinical trial registered with www.clinicaltrials.gov (NCT02338843).

Angiotensin II for the Treatment of Vasodilatory Shock.

BACKGROUND: Vasodilatory shock that does not respond to high-dose vasopressors is associated with high mortality. We investigated the effectiveness of angiotensin II for the treatment of patients with this condition. METHODS: We randomly assigned patients with vasodilatory shock who were receiving more than 0.2 µg of norepinephrine per kilogram of body weight per minute or the equivalent dose of another vasopressor to receive infusions of either angiotensin II or placebo. The primary end point was a response with respect to mean arterial pressure at hour 3 after the start of infusion, with response defined as an increase from baseline of at least 10 mm Hg or an increase to at least 75 mm Hg, without an increase in the dose of background vasopressors. RESULTS: A total of 344 patients were assigned to one of the two regimens; 321 received a study intervention (163 received angiotensin II, and 158 received placebo) and were included in the analysis. The primary end point was reached by more patients in the angiotensin II group (114 of 163 patients, 69.9%) than in the placebo group (37 of 158 patients, 23.4%) (odds ratio, 7.95; 95% confidence interval [CI], 4.76 to 13.3; P<0.001). At 48 hours, the mean improvement in the cardiovascular Sequential Organ Failure Assessment (SOFA) score (scores range from 0 to 4, with higher scores indicating more severe dysfunction) was greater in the angiotensin II group than in the placebo group (-1.75 vs. -1.28, P=0.01). Serious adverse events were reported in 60.7% of the patients in the angiotensin II group and in 67.1% in the placebo group. Death by day 28 occurred in 75 of 163 patients (46%) in the angiotensin II group and in 85 of 158 patients (54%) in the placebo group (hazard ratio, 0.78; 95% CI, 0.57 to 1.07; P=0.12). CONCLUSIONS: Angiotensin II effectively increased blood pressure in patients with vasodilatory shock that did not respond to high doses of conventional vasopressors. (Funded by La Jolla Pharmaceutical Company; ATHOS-3 ClinicalTrials.gov number, NCT02338843 .).

Angiotensin II treatment is associated with improved oxygenation in ARDS patients with refractory vasodilatory shock.

BACKGROUND: The physiological effects of renin-angiotensin system modulation in acute respiratory distress syndrome (ARDS) remain controversial and have not been investigated in randomized trials. We sought to determine whether angiotensin-II treatment is associated with improved oxygenation in shock-associated ARDS. METHODS: Post-hoc subgroup analysis of the Angiotensin Therapy for High Output Shock (ATHOS-3) trial. We studied patients who met modified Berlin ARDS criteria at enrollment. The primary outcome was PaO2/FiO2-ratio (P:F) at 48-h adjusted for baseline P:F. Secondary outcomes included oxygenation index, ventilatory ratio, PEEP, minute-ventilation, hemodynamic measures, patients alive and ventilator-free by day-7, and mortality. RESULTS: Of 81 ARDS patients, 34 (42%) and 47 (58%) were randomized to angiotensin-II or placebo, respectively. In angiotensin-II patients, mean P:F increased from 155 mmHg (SD: 69) at baseline to 265 mmHg (SD: 160) at hour-48 compared with no change with placebo (148 mmHg (SD: 63) at baseline versus 164 mmHg (SD: 74) at hour-48)(baseline-adjusted difference: + 98.4 mmHg [95%CI 35.2-161.5], p = 0.0028). Similarly, oxygenation index decreased by - 6.0 cmH2O/mmHg at hour-48 with angiotensin-II versus - 0.4 cmH2O/mmHg with placebo (baseline-adjusted difference: -4.8 cmH2O/mmHg, [95%CI - 8.6 to - 1.1], p = 0.0273). There was no difference in PEEP, minute ventilation, or ventilatory ratio. Twenty-two (64.7%) angiotensin-II patients had sustained hemodynamic response to treatment at hour-3 versus 17 (36.2%) placebo patients (absolute risk-difference: 28.5% [95%CI 6.5-47.0%], p = 0.0120). At day-7, 7/34 (20.6%) angiotensin-II patients were alive and ventilator-free versus 5/47(10.6%) placebo patients. Day-28 mortality was 55.9% in the angiotensin-II group versus 68.1% in the placebo group. CONCLUSIONS: In post-hoc analysis of the ATHOS-3 trial, angiotensin-II was associated with improved oxygenation versus placebo among patients with ARDS and catecholamine-refractory vasodilatory shock. These findings provide a physiologic rationale for trials of angiotensin-II as treatment for ARDS with vasodilatory shock. TRIAL REGISTRATION: ClinicalTrials.Gov Identifier: NCT02338843 (Registered January 14th 2015).

Outcome Prediction in Patients with Severe COVID-19 Requiring Extracorporeal Membrane Oxygenation-A Retrospective International Multicenter Study.

The role of veno-venous extracorporeal membrane oxygenation therapy (V-V ECMO) in severe COVID-19 acute respiratory distress syndrome (ARDS) is still under debate and conclusive data from large cohorts are scarce. Furthermore, criteria for the selection of patients that benefit most from this highly invasive and resource-demanding therapy are yet to be defined. In this study, we assess survival in an international multicenter cohort of COVID-19 patients treated with V-V ECMO and evaluate the performance of several clinical scores to predict 30-day survival. METHODS: This is an investigator-initiated retrospective non-interventional international multicenter registry study (NCT04405973, first registered 28 May 2020). In 127 patients treated with V-V ECMO at 15 centers in Germany, Switzerland, Italy, Belgium, and the United States, we calculated the Sequential Organ Failure Assessment (SOFA) Score, Simplified Acute Physiology Score II (SAPS II), Acute Physiology And Chronic Health Evaluation II (APACHE II) Score, Respiratory Extracorporeal Membrane Oxygenation Survival Prediction (RESP) Score, Predicting Death for Severe ARDS on V­V ECMO (PRESERVE) Score, and 30-day survival. RESULTS: In our study cohort which enrolled 127 patients, overall 30-day survival was 54%. Median SOFA, SAPS II, APACHE II, RESP, and PRESERVE were 9, 36, 17, 1, and 4, respectively. The prognostic accuracy for all these scores (area under the receiver operating characteristic-AUROC) ranged between 0.548 and 0.605. CONCLUSIONS: The use of scores for the prediction of mortality cannot be recommended for treatment decisions in severe COVID-19 ARDS undergoing V-V ECMO; nevertheless, scoring results below or above a specific cut-off value may be considered as an additional tool in the evaluation of prognosis. Survival rates in this cohort of COVID-19 patients treated with V­V ECMO were slightly lower than those reported in non-COVID-19 ARDS patients treated with V-V ECMO.

Sensitivity to angiotensin II dose in patients with vasodilatory shock: a prespecified analysis of the ATHOS-3 trial.

BACKGROUND: Early clinical data showed that some patients with vasodilatory shock are responsive to low doses of angiotensin II. The objective of this analysis was to compare clinical outcomes in patients requiring ≤ 5 ng kg-1 min-1 angiotensin II at 30 min (≤ 5 ng kg-1 min-1 subgroup) to maintain mean arterial pressure (MAP) ≥ 75 mmHg versus patients receiving > 5 ng kg-1 min-1 angiotensin II at 30 min (> 5 ng kg-1 min-1 subgroup). Data from angiotensin II-treated patients enrolled in the ATHOS-3 trial were used. RESULTS: The subgroup of patients whose angiotensin II dose was down-titrated from 20 ng kg-1 min-1 at treatment initiation to ≤ 5 ng kg-1 min-1 at 30 min (79/163) had significantly lower endogenous serum angiotensin II levels and norepinephrine-equivalent doses and significantly higher MAP versus the > 5 ng kg-1 min-1 subgroup (84/163). Patients in the ≤ 5 ng kg-1 min-1 subgroup were more likely to have a MAP response at 3 h versus those in the > 5 ng kg-1 min-1 subgroup (90% vs. 51%, respectively; odds ratio, 8.46 [95% CI 3.63-19.7], P < 0.001). Day 28 survival was also higher in the ≤ 5 ng kg-1 min-1 subgroup versus the > 5 ng kg-1 min-1 subgroup (59% vs. 33%, respectively; hazard ratio, 0.48 [95% CI 0.28-0.72], P = 0.0007); multivariate analyses supported the survival benefit in patients with lower angiotensin II levels. The ≤ 5 ng kg-1 min-1 subgroup had a more favorable safety profile and lower treatment discontinuation rate than the > 5 ng kg-1 min-1 subgroup. CONCLUSIONS: This prespecified analysis showed that down-titration to ≤ 5 ng kg-1 min-1 angiotensin II at 30 min is an early predictor of favorable clinical outcomes which may be related to relative angiotensin II insufficiency.

Teaching suturing in a workshop setting: a comparison of several models.

OBJECTIVES: Suturing is taught in workshops using a variety of models. The purpose of this study is to compare the resemblance to human skin of four models commonly used to teach suturing: pig skin, beef tongue, hot dog and latex glove. METHODS: 5 centimeter biconvex incisions were made in each of the models and closed by 50 physician study volunteers comprised of 33 board-certified physicians and 17 resident physicians. They rated each model on a scale of 1 to 4, where 4 closely resembles human skin and 1 does not resemble human skin. RESULTS: The following mean ratings were given by study volunteers: beef tongue 3.5 +/- 0.5, pig skin 3.2 +/- 0.8, latex glove 1.6 +/- 0.7, hot dog 1.4 +/- 0.6. CONCLUSION: Beef tongue and pig skin were rated highest by study volunteers. However, pig skin is much cheaper than beef tongue. Pig skin is the best inexpensive model for teaching skin suturing of the four models studied.

Problem based learning and medical malpractice: does how you've been trained make a difference?

Testing the hypothesis that physicians trained in problem based learning formats versus traditional lecture based formats develop equally strong physician-patient relationships, the rates of malpractice filings against graduates trained in each format at the John A. Burns' School of Medicine were compared. With the graduation of 10 more PBL classes, statistically significant differences between the two groups could be obtained.

Iron deprivation blocks multilineage haematopoietic differentiation by inhibiting induction of p21(WAF1/CIP1).

Iron is required for the differentiation of HL-60 cells along the monocyte lineage in vitro, reflecting a requirement for iron in the transcriptional induction of the p21(WAF1/CIP1) gene. To determine if the same requirement holds true for differentiation in other cell lineages and for primary human CD34(+) bone marrow precursor cells, we induced granulocyte differentiation by treating HL-60 cells with dimethyl sulphoxide, and erythroid or megakaryocytic differentiation by treating K562 cells with butyrate or phorbol myristate acetate, respectively. Nitro blue tetrazolium reduction, expression of haem, or expression of CD41 was used to assess granulocytic, erythroid, or megakaryocytic differentiation respectively. Purified CD34(+) cells were cultured with granulocyte/macrophage-colony stimulating factor and stem cell factor to induce myelomonocytic differentiation. Iron deprivation was induced by desferrioxamine. p21(WAF1/CIP1) antisense oligonucleotides were used to inhibit p21 expression. Iron deprivation blocked p21 induction as judged by real-time polymerase chain reaction assays. In addition, both iron deprivation and p21 antisense blocked CD34(+) cell differentiation. These observations were not explained by induction of widespread apoptosis under conditions of iron deprivation. We concluded that both iron and functional p21(WAF1/CIP1) are required for in vitro differentiation of human haematopoietic precursors along multiple cell lineages.

Connective tissue growth factor (CTGF) expression and outcome in adult patients with acute lymphoblastic leukemia.

We compared the gene expression profile of adult acute lymphoblastic leukemia (ALL) to normal hematopoietic and non-ALL samples using oligonucleotide arrays. Connective tissue growth factor (CTGF) was the highest overexpressed gene in B-cell ALL compared with the other groups, and displayed heterogeneous expression, suggesting it might have prognostic relevance. CTGF expression was examined by quantitative reverse transcriptase-polymerase chain reaction (ORT-PCR) on 79 adult ALL specimens. CTGF expression levels were significantly increased in ALL cases with B-lineage (P < .001), unfavorable cytogenetics (P < .001), and blasts expressing CD34 (P < .001). In a multivariate proportional hazards model, higher CTGF expression levels corresponded to worsening of overall survival (OS; hazard ratio 1.36, for each 10-fold increase in expression; P = .019). Further studies are ongoing to confirm the prognostic value of CTGF expression in ALL and to investigate its role in normal and abnormal lymphocyte biology.

Differentiation of functional dendritic cells and macrophages from human peripheral blood monocyte precursors is dependent on expression of p21 (WAF1/CIP1) and requires iron.

Iron is required for monocyte/macrophage differentiation of HL-60 leukaemia cells. Differentiation requires induction of the cyclin-dependent kinase inhibitor p21 (WAF1/CIP1), and cell cycle arrest at the G1/S checkpoint. With iron depletion, p21 induction and differentiation are blocked. To establish the roles of iron and p21 in normal monocyte/macrophage differentiation, we examined generation of dendritic cells (DCs) and macrophages from peripheral monocytes. Monocytes were cultured with interleukin 4 and granulocyte-macrophage colony-stimulating factor (GM-CSF), then treated with lipopolysaccharide to produce DCs or with M-CSF to produce macrophages. Iron deprivation was induced by desferrioxamine (DF). Monocyte-derived DCs had characteristic phenotype and morphology, and stimulated proliferation of naïve allogeneic T lymphocytes. In contrast, DCs generated under iron deprivation were phenotypically undifferentiated and did not stimulate T cells. Similarly, macrophages expressed a characteristic phenotype and morphology, and phagocytosed latex beads, but macrophages generated under iron deprivation failed to develop a mature phenotype and had impaired phagocytosis. Iron deprivation blocked induction of p21 (WAF1/CIP1) expression in both DC and macrophage cultures. Furthermore, p21 antisense oligonucleotides, but not sense oligonucleotides, inhibited both DC and macrophage differentiation. These data indicate that a key role of iron in haematopoiesis is to support induction of p21 which, in turn, is required for DC and macrophage differentiation.

Prognostic significance of CD38 and CD20 expression as assessed by quantitative flow cytometry in chronic lymphocytic leukaemia.

CD38 expression on chronic lymphocytic leukaemia (CLL) cells is a poor prognostic factor, however, methods for measuring this vary. The QuantiBRITETM flow cytometry (FC) system yields an absolute antigen expression value (antibodies bound/cell, ABC) and may be useful in standardizing CD38 expression analysis. We evaluated cryopreserved pretreatment CLL cells for CD20 ABC, CD38 ABC, and percentage of CD38+ B cells from 131 patients requiring therapy. The 92 patients (70%) with >/= 100 CD38 ABC had worse overall survival (OS; 34% at 5 years) compared with those with < 100 CD38 ABC (70% at 5 years, mortality hazard ratio 2.30, 95% confidence interval 1.28-4.12; two-tailed P = 0.003). Among the 64 patients with < 30% CD38+ cells, OS of the 25 with >/= 100 ABC was worse than that of the 39 with < 100 ABC (P = 0.018). OS of patients with < 30% CD38+ cells and >/= 100 ABC was actually similar to that of patients with >/= 30% CD38+ cells. BrightCD20 expression (>/= 20 000 ABC) was not associated with a worse OS (P = 0.10). The presence of >/= 100 CD38 ABC in CLL patients requiring therapy is an unfavourable prognostic factor for OS and quantitative FC may be superior to percentage CD38+ cell assessment. Prospective trials are required to determine more precisely the prognostic significance of absolute expression levels in fresh CLL cells.