Determinants of death in critically ill COVID-19 patients during the first wave of COVID-19: a multicenter study in Brazil

OBJECTIVE

To evaluate clinical outcomes and factors associated with mortality, focusing on secondary infections, in critically ill patients with COVID-19 in three Brazilian hospitals during the first pandemic wave.

METHODS

This was a retrospective observational study involving adult patients with COVID-19 admitted to one of the participating ICUs between March and August of 2020. We analyzed clinical features, comorbidities, source of SARS-CoV-2 infection, laboratory data, microbiology data, complications, and causes of death. We assessed factors associated with in-hospital mortality using logistic regression models.

RESULTS

We included 645 patients with a mean age of 61.4 years. Of those, 387 (60.0%) were male, 12.9% (83/643) had undergone solid organ transplant, and almost 10% (59/641) had nosocomial COVID-19 infection. During ICU stay, 359/644 patients (55.7%) required invasive mechanical ventilation, 225 (34.9%) needed renal replacement therapy, 337 (52.2%) received vasopressors, and 216 (33.5%) had hospital-acquired infections (HAIs), mainly caused by multidrug-resistant gram-negative bacteria. HAIs were independently associated with a higher risk of death. The major causes of death were refractory shock and multiple organ dysfunction syndrome but not ARDS, as previously reported in the literature.

CONCLUSIONS

In this study, most of our cohort required invasive mechanical ventilation and almost one third had HAIs, which were independently associated with a higher risk of death. Other factors related to death were Charlson Comorbidity Index, SOFA score at admission, and clinical complications during ICU stay. Nosocomial COVID-19 infection was not associated with death. The main immediate causes of death were refractory shock and multiple organ dysfunction syndrome.

Implementation of sepsis bundles in public hospitals in Brazil: a prospective study with heterogeneous results

Background

Public hospitals in emerging countries pose a challenge to quality improvement initiatives in sepsis. Our objective was to evaluate the results of a quality improvement initiative in sepsis in a network of public institutions and to assess potential differences between institutions that did or did not achieve a reduction in mortality.

Methods

We conducted a prospective study of patients with sepsis or septic shock. We collected baseline data on compliance with the Surviving Sepsis Campaign 6-h bundles and mortality. Afterward, we initiated a multifaceted quality improvement initiative for patients with sepsis or septic shock in all hospital sectors. The primary outcome was hospital mortality over time. The secondary outcomes were the time to sepsis diagnosis and compliance with the entire 6-h bundles throughout the intervention. We defined successful institutions as those where the mortality rates decreased significantly over time, using a logistic regression model. We analyzed differences over time in the secondary outcomes by comparing the successful institutions with the nonsuccessful ones. We assessed the predictors of in-hospital mortality using logistic regression models. All tests were two-sided, and a p value less than 0.05 indicated statistical significance.

Results

We included 3435 patients from the emergency departments (50.7%), wards (34.1%), and intensive care units (15.2%) of 9 institutions. Throughout the intervention, there was an overall reduction in the risk of death, in the proportion of septic shock, and the time to sepsis diagnosis, as well as an improvement in compliance with the 6-h bundle. The time to sepsis diagnosis, but not the compliance with bundles, was associated with a reduction in the risk of death. However, there was a significant reduction in mortality in only two institutions. The reduction in the time to sepsis diagnosis was greater in the successful institutions. By contrast, the nonsuccessful sites had a greater increase in compliance with the 6-h bundle.

Conclusions

Quality improvement initiatives reduced sepsis mortality in public Brazilian institutions, although not in all of them. Early recognition seems to be a more relevant factor than compliance with the 6-h bundle.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1858-z) contains supplementary material, which is available to authorized users.

Serum concentrations of vitamin D and organ dysfunction in patients with severe sepsis and septic shock

Objectives

To evaluate the serum concentrations of vitamin D and their variations in patients with severe sepsis or septic shock and in control subjects upon admission and after 7 days of hospitalization in the intensive care unit and to correlate these concentrations with the severity of organ dysfunction.

Methods

This case-control, prospective, observational study involved patients aged > 18 years with severe sepsis or septic shock paired with a control group. Serum vitamin D concentrations were measured at inclusion (D0) and on the seventh day after inclusion (D7). Severe deficiency was defined as vitamin D levels < 10ng/ml, deficiency as levels between 10 and 20ng/ml, insufficiency as levels between 20 and 30ng/ml, and sufficiency as levels ≥ 30ng/mL. We considered a change to a higher ranking, together with a 50% increase in the absolute concentration, to represent an improvement.

Results

We included 51 patients (26 with septic shock and 25 controls). The prevalence of vitamin D concentration ≤ 30ng/ml was 98%. There was no correlation between the serum concentration of vitamin D at D0 and the SOFA score at D0 or D7 either in the general population or in the group with septic shock. Patients with improvement in vitamin D deficiency had an improved SOFA score at D7 (p = 0.013).

Conclusion

In the population studied, patients with septic shock showed improvement in the serum concentrations of vitamin D on the seventh day compared with the controls. We also found a correlation between higher vitamin D concentrations and a greater decrease in the severity of organ dysfunction.

Diabetes mellitus and impaired glucose tolerance are underdiagnosed in intensive care units

Objective

To evaluate the presence of diabetes mellitus and impaired glucose tolerance in intensive care unit inpatients.

Methods

The study included patients in post-surgical care for elective and emergency surgery and excluded those patients with known diabetes mellitus. To diagnose prior serum glucose level disorders, we considered the value of glycated hemoglobin (HbA1c) at the time of admission, classifying the patients as normal (<5.7%), glucose intolerant (5.7-6.4%) or diabetic (>6.4%). During the first 3 days of the patient's hospital stay, glycemic control and clinical complications were assessed. Mortality was monitored for 28 days. For the statistical analyses, chi-square, ANOVA, student's t, Kruskal-Wallis or Mann Whitney tests were used.

Results

Thirty patients were included in the present study, 53% of whom were women; the patients had a mean age of 53.4±19.7 years and an APACHE II score of 13.6±6.6. The majority of patients were admitted for severe sepsis or septic shock followed by post-operative care for elective surgery, oncological surgery, multiple traumas and emergency surgery. When classifying these patients according to HbA1c, despite the absence of a prior history of diabetes mellitus, only 13.3% had a normal HbA1c level, 23.3% had levels compatible with the diagnosis of diabetes mellitus and 63.3% had levels compatible with impaired glucose tolerance. We found a significant association between the diagnosis of diabetes mellitus or impaired glucose tolerance and the use of vasoactive drugs (p=0.04).

Conclusion

A high prevalence of undiagnosed diabetes mellitus and impaired glucose tolerance was observed in inpatients at a general intensive care unit.

Predictive value of pulse pressure variation for fluid responsiveness in septic patients using lung-protective ventilation strategies

Background

The applicability of pulse pressure variation (ΔPP) to predict fluid responsiveness using lung-protective ventilation strategies is uncertain in clinical practice. We designed this study to evaluate the accuracy of this parameter in predicting the fluid responsiveness of septic patients ventilated with low tidal volumes (TV) (6 ml kg⁻¹).

Methods

Forty patients after the resuscitation phase of severe sepsis and septic shock who were mechanically ventilated with 6 ml kg⁻¹ were included. The ΔPP was obtained automatically at baseline and after a standardized fluid challenge (7 ml kg⁻¹). Patients whose cardiac output increased by more than 15% were considered fluid responders. The predictive values of ΔPP and static variables [right atrial pressure (RAP) and pulmonary artery occlusion pressure (PAOP)] were evaluated through a receiver operating characteristic (ROC) curve analysis.

Results

Thirty-four patients had characteristics consistent with acute lung injury or acute respiratory distress syndrome and were ventilated with high levels of PEEP [median (inter-quartile range) 10.0 (10.0–13.5)]. Nineteen patients were considered fluid responders. The RAP and PAOP significantly increased, and ΔPP significantly decreased after volume expansion. The ΔPP performance [ROC curve area: 0.91 (0.82–1.0)] was better than that of the RAP [ROC curve area: 0.73 (0.59–0.90)] and pulmonary artery occlusion pressure [ROC curve area: 0.58 (0.40–0.76)]. The ROC curve analysis revealed that the best cut-off for ΔPP was 6.5%, with a sensitivity of 0.89, specificity of 0.90, positive predictive value of 0.89, and negative predictive value of 0.90.

Conclusions

Automatized ΔPP accurately predicted fluid responsiveness in septic patients ventilated with low TV.