Bias reduction in repeated-measures observational studies by the use of propensity score: The case of enteral sedation for critically ill patients

No association between use of angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers prior to hospital admission and clinical course of COVID-19 in the COvid MEdicaTion (COMET) study

Since the outbreak of SARS-CoV-2, also known as COVID-19, conflicting theories have circulated on the influence of angiotensin-converting enzyme inhibitors (ACEi) and angiotensin II receptor blockers (ARB) on incidence and clinical course of COVID-19, but data are scarce. The COvid MEdicaTion (COMET) study is an observational, multinational study that focused on the clinical course of COVID-19 (i.e. hospital mortality and intensive care unit [ICU] admission), and included COVID-19 patients who were registered at the emergency department or admitted to clinical wards of 63 participating hospitals. Pharmacists, clinical pharmacologists or treating physicians collected data on medication prescribed prior to admission. The association between the medication and composite clinical endpoint, including mortality and ICU admission, was analysed by multivariable logistic regression models to adjust for potential confounders. A total of 4870 patients were enrolled. ACEi were used by 847 (17.4%) patients and ARB by 761 (15.6%) patients. No significant association was seen with ACEi and the composite endpoint (adjusted odds ratio [OR] 0.94; 95% confidence interval [CI] 0.79 to 1.12), mortality (OR 1.03; 95%CI 0.84 to 1.27) or ICU admission (OR 0.96; 95%CI 0.78 to 1.19) after adjustment for covariates. Similarly, no association was observed between ARB and the composite endpoint (OR 1.09; 95%CI 0.90 to 1.30), mortality (OR 1.12; OR 0.90 to 1.39) or ICU admission (OR 1.21; 95%CI 0.98 to 1.49). In conclusion, we found no evidence of a harmful or beneficial effect of ACEi or ARB use prior to hospital admission on ICU admission or hospital mortality.

Enteral versus intravenous approach for the sedation of critically ill patients: a randomized and controlled trial

Background

ICU patients must be kept conscious, calm, and cooperative even during the critical phases of illness. Enteral administration of sedative drugs might avoid over sedation, and would be as adequate as intravenous administration in patients who are awake, with fewer side effects and lower costs. This study compares two sedation strategies, for early achievement and maintenance of the target light sedation.

Methods

This was a multicenter, single-blind, randomized and controlled trial carried out in 12 Italian ICUs, involving patients with expected mechanical ventilation duration > 72 h at ICU admission and predicted mortality > 12% (Simplified Acute Physiology Score II > 32 points) during the first 24 h on ICU. Patients were randomly assigned to receive intravenous (midazolam, propofol) or enteral (hydroxyzine, lorazepam, and melatonin) sedation. The primary outcome was percentage of work shifts with the patient having an observed Richmond Agitation-Sedation Scale (RASS) = target RASS ±1. Secondary outcomes were feasibility, delirium-free and coma-free days, costs of drugs, length of ICU and hospital stay, and ICU, hospital, and one-year mortality.

Results

There were 348 patients enrolled. There were no differences in the primary outcome: enteral 89.8% (74.1–100), intravenous 94.4% (78–100), p = 0.20. Enteral-treated patients had more protocol violations: n = 81 (46.6%) vs 7 (4.2%), p < 0.01; more self-extubations: n = 14 (8.1%) vs 4 (2.4%), p = 0.03; a lighter sedative target (RASS = 0): 93% (71–100) vs 83% (61–100), p < 0.01; and lower total drug costs: 2.39 (0.75–9.78) vs 4.15 (1.20–20.19) €/day with mechanical ventilation (p = 0.01).

Conclusions

Although enteral sedation of critically ill patients is cheaper and permits a lighter sedation target, it is not superior to intravenous sedation for reaching the RASS target.

Trial registration

ClinicalTrials.gov, NCT01360346. Registered on 25 March 2011.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2280-x) contains supplementary material, which is available to authorized users.

Postoperative complications in cirrhotic pediatric deceased donor liver transplantation: Focus on transfusion therapy

Intraoperative transfusions seem associated with patient death and graft failure after PLTx. A retrospective analysis of recipients' and donors' characteristics and transplantation data in a cohort of patients undergoing PLTx from 2002 to 2009 at the Bergamo General Hospital was performed. A two-stage hierarchical Cox proportional hazard regression with forward stepwise selection was used to identify the main risk factors for major complications. In addition, propensity score analysis was used to adjust risk estimates for possible selection biases in the use of blood products. Over the 12-year period, 232 pediatric cirrhotic patients underwent PLTx. One-year patient and graft survival rates were 92.3% and 83.7%, respectively. The Kaplan-Meier shows that the main decrease in both graft and patient survival occurs during the first months post-transplantation. At the same time, it appears that most of the complications occur during the first month post-transplantation. One-month and 1-year patient complication-free survival rates were 24.8% and 12.1%, respectively. Our study shows that intraoperative red blood cells and platelet transfusions are independent risk factors for developing one or more major complications in the first year after PLTx. Decreasing major complications will improve the health status and overall long-term patient survival after pediatric PLTx.

The combined use of aspirin, a statin, and blood pressure-lowering agents (polypill components) and the risk of vascular morbidity and mortality in patients with coronary artery disease

BACKGROUND AND AIMS

Patients with established coronary artery disease (CAD) are likely to receive a combination of aspirin, a statin, and blood pressure (BP)-lowering agents. Combining these pharmacologic agents into a cardiovascular combination pill, such as a polypill, could be considered to reduce prescription gaps and nonadherence in high-risk patients. We aimed to evaluate the effect of the concomitant use of aspirin, a statin, and BP-lowering agent(s) in patients with CAD on vascular morbidity and mortality in current clinical practice in an observational study to provide insights in the combination pill concept related to feasibility and applicability.

METHODS

In total, 2,706 patients with CAD enrolled in the Second Manifestations of ARTerial disease study were followed for the occurrence of a subsequent vascular event (ie, myocardial infarction, ischemic cerebrovascular accident, vascular death) and all-cause mortality. The relationship between combination therapy and cardiovascular events and all-cause mortality was assessed using Cox proportional hazards regression models to calculate hazards ratios (HRs) with a 95% CI. Both covariate and propensity score adjusting methods were used to reduce confounding by indication.

RESULTS

A combination of aspirin, a statin, and ≥1 BP-lowering agent(s) was used by 67% of the patients. During a median of 5.0 years (interquartile range 2.4-10.2 years), 347 vascular events occurred and 162 patients died. Combination therapy with aspirin, statin, and ≥1 BP-lowering agent was associated with a lower risk of myocardial infarction (HR 0.68, 95% CI 0.49-0.96), ischemic cerebrovascular accident (HR 0.37, 95% CI 0.16-0.84), composite vascular end point (HR 0.66, 95% CI 0.49-0.88), vascular mortality (HR 0.53, 95% CI 0.33-0.85), and all-cause mortality (HR 0.69, 95% CI 0.49-0.96) compared with the absence of combination therapy, after adjusting for confounding covariates in a propensity score. The use of 1 or only 2 components of combination therapy was associated with a higher risk for cardiovascular events compared with the combined use of aspirin, a statin, and ≥1 BP-lowering agent(s).

CONCLUSION

Two-thirds of the patients with CAD use a combination of aspirin, a statin, and ≥1 BP-lowering agent(s), components of a cardiovascular fixed-dose combination pill. Combination therapy with these agents is associated with a lower risk of vascular events and total mortality. Although treatment effect in observational studies should be interpreted with caution, the results of this study support supposed benefits from combination therapy. However, the effect of fixed-dose combination pill on clinical outcome needs to be demonstrated in randomized clinical trials.