Secondary use of data extracted from a clinical information system to assess the adherence of tidal volume and its impact on outcomes

OBJECTIVES

To extract data from clinical information systems to automatically calculate high-resolution quality indicators to assess adherence to recommendations for low tidal volume.

DESIGN

We devised two indicators: the percentage of time under mechanical ventilation with excessive tidal volume (>8mL/kg predicted body weight) and the percentage of patients who received appropriate tidal volume (≤8mL/kg PBW) at least 80% of the time under mechanical ventilation. We developed an algorithm to automatically calculate these indicators from clinical information system data and analyzed associations between them and patients' characteristics and outcomes.

SETTINGS

This study has been carried out in our 30-bed polyvalent intensive care unit between January 1, 2014 and November 30, 2019.

PATIENTS

All patients admitted to intensive care unit ventilated >72h were included.

INTERVENTION

Use data collected automatically from the clinical information systems to assess adherence to tidal volume recommendations and its outcomes.

MAIN VARIABLES OF INTEREST

Mechanical ventilation days, ICU length of stay and mortality.

RESULTS

Of all admitted patients, 340 met the inclusion criteria. Median percentage of time under mechanical ventilation with excessive tidal volume was 70% (23%-93%); only 22.3% of patients received appropriate tidal volume at least 80% of the time. Receiving appropriate tidal volume was associated with shorter duration of mechanical ventilation and intensive care unit stay. Patients receiving appropriate tidal volume were mostly male, younger, taller, and less severely ill. Adjusted intensive care unit mortality did not differ according to percentage of time with excessive tidal volume or to receiving appropriate tidal volume at least 80% of the time.

CONCLUSIONS

Automatic calculation of process-of-care indicators from clinical information systems high-resolution data can provide an accurate and continuous measure of adherence to recommendations. Adherence to tidal volume recommendations was associated with shorter duration of mechanical ventilation and intensive care unit stay.

Impact of Aspergillus spp. isolation in the first 24 hours of admission in critically ill patients with severe influenza virus pneumonia

OBJECTIVE

To determine the incidence and impact of Aspergillus spp. isolation (AI) on ICU mortality in critically ill patients with severe influenza pneumonia during the first 24h of admission.

DESIGN

Secondary analysis of an observational and prospective cohort study.

SETTING

ICUs voluntary participating in the Spanish severe Influenza pneumonia registry, between June 2009 and June 2019.

PATIENTS

Consecutive patients admitted to the ICU with diagnosis of severe influenza pneumonia, confirmed by real-time polymerase chain reaction.

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

Incidence of AI in respiratory samples. Demographic variables, comorbidities, need for mechanical ventilation and the presence of shock according at admission. Acute Physiology and Chronic Health Evaluation II (APACHE II) scale calculated on ICU admission.

RESULTS

3702 patients were analyzed in this study. AI incidence was 1.13% (n=42). Hematological malignancies (OR 4.39, 95% CI 1.92-10.04); HIV (OR 3.83, 95% CI 1.08-13.63), and other immunosuppression situations (OR 4.87, 95% CI 1.99-11.87) were factors independently associated with the presence of Aspergillus spp. The automatic CHAID decision tree showed that hematologic disease with an incidence of 3.3% was the most closely AI related variable. Hematological disease (OR 2.62 95% CI 1.95-3.51), immunosuppression (OR 2.05 95% CI 1.46-2.88) and AI (OR 3.24, 95% CI 1.60-6.53) were variables independently associated with ICU mortality.

CONCLUSIONS

Empirical antifungal treatment in our population may only be justified in immunocompromised patients. In moderate-high risk cases, active search for Aspergillus spp. should be implemented.

Identification of Environmental Chemicals Associated with the Development of Toxicant-associated Fatty Liver Disease in Rodents

BACKGROUND

Toxicant-associated fatty liver disease (TAFLD) is a recently identified form of nonalcoholic fatty liver disease (NAFLD) associated with exposure to industrial chemicals and environmental pollutants. Numerous studies have been conducted to test the association between industrial chemicals/environmental pollutants and fatty liver disease both in vivo and in vitro.

OBJECTIVES

The objective of the article is to report a list of chemicals associated with TAFLD.

METHODS

Two federal databases of rodent toxicology studies-Toxicological Reference Database (ToxRefDB; Environmental Protection Agency) and Chemical Effects in Biological Systems (CEBS, National Toxicology Program)-were searched for liver end points. Combined, these 2 databases archive nearly 2,000 rodent studies. Toxicant-associated steatohepatitis (TASH) descriptors including fatty change, fatty necrosis, Oil red O-positive staining, steatosis, and lipid deposition were queried.

RESULTS

Using these search terms, 123 chemicals associated with fatty liver were identified. Pesticides and solvents were the most frequently identified chemicals, while polychlorinated biphenyls (PCBs)/dioxins were the most potent. About 44% of identified compounds were pesticides or their intermediates, and >10% of pesticide registration studies in ToxRefDB were associated with fatty liver. Fungicides and herbicides were more frequently associated with fatty liver than insecticides.

CONCLUSION

More research on pesticides, solvents, metals, and PCBs/dioxins in NAFLD/TAFLD is warranted due to their association with liver damage.

Hypercoagulability in patients with obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) has been linked to cardiovascular complications such as stroke and myocardial infarction. Previous studies demonstrate that OSA patients show elevated fibrinogen levels and increased platelet aggregation that are reversed with 1 night of nasal continuous positive airway pressure treatment (NCPAP). Questioning overall coagulability in OSA, we examined whole blood coagulability in 11 chronically NCPAP treated OSA subjects, 22 previously untreated OSA subjects, and in 16 of these after 1 night of NCPAP treatment.

PATIENTS AND METHODS

During full polysomnography, subjects from each group had blood drawn prior to bedtime (21:00 h) and upon waking in the morning (07:00 h).

RESULTS

Untreated OSA patients had faster P.M. clotting times than chronically treated OSA patients (3.33+/-0.31 versus 6.12+/- 0.66 min, P<0.05 by ANOVA). A.M. values showed similar results (4.31+/- 0.34 min versus 7.08+/-0.52 min, P<0.05 by ANOVA) for the respective groups. One overnight treatment with nasal CPAP did not produce a significant change in A.M. whole blood coagulability (4.35 +/-0.43 to 5.31+/-0.53 min; n=16; P=0.1) in 16 treated subjects.

CONCLUSIONS

These data indicate a relationship between obstructive sleep apnea and blood hypercoagulability status that appears to be reversed by chronic NCPAP treatment. These data suggest that NCPAP might protect against the development of cardiovascular complications in OSA patients.

Pulmonary edema develops after recurrent obstructive apneas

There are anecdotal reports of pulmonary edema after a night of recurrent obstructive apneas (OAs) in humans, but no data on lung water, gas exchange, filling pressure, or cardiac output (Q) exist in these patients. By clamping the endotracheal tube of eight intubated, anesthesized dogs, we created repetitive OAs of 45-s duration at 30-s intervals, for 8 h. Five additional dogs without apneas, but identically instrumented, were studied simultaneously, serving as nonapneic controls. Sa (O(2)) was measured by intraarterial catheter, pulmonary capillary wedge pressure (Pcw), continuous cardiac output (Q), and mixed venous oxygen saturation (Sv(O(2))) were measured by flotation catheter. Basal and hourly hemodynamics and blood gases (arterial and venous) under steady state respiration were measured. Venous admixture (Q S/Q T) was calculated by standard equations. Pa(O(2)) from the beginning to the end of the experiment fell from 89.6 to 82.8 mm Hg in apneic animals and from 92.2 to 85.5 mm Hg in controls. The Q S/Q T increased in both groups but more so in the apnea group (3.3 to 19.4%) than in nonapneic controls (3.1 to 7.9%). Neither Q nor Pcw changed significantly in either group. Lung wet/dry weight was 5.40 +/- 0.93 in apneic animals and 5.00 +/- 0.67 in controls. Light microscopy showed gross alveolar fluid in three apneic dogs, and electron microscopy showed interstitial fluid in two additional apneic dogs. One of the lung edema dogs expired of acute heart failure in the seventh hour of the experiment. Worsening of gas exchange and histology suggest that lung edema can result from recurrent OAs.

Assessment of the prognosis of coronary patients: performance and customization of generic severity indexes

STUDY OBJECTIVE

To assess the prognostic performance of general severity systems (APACHE II [acute physiology and chronic health evaluation], simplified acute physiology score [SAPS II], and mortality probability models [MPM II]) in coronary patients and to derive new customized indexes for coronary patients using a reduced number of variables.

DESIGN

Inception cohort.

SETTING

Adult medical and surgical ICUs in 17 hospitals in Catalonia and the Balearic Islands.

PATIENTS

Four hundred fifty-six patients with acute myocardial infarction.

MEASUREMENTS AND RESULTS

The APACHE II, SAPS II, and MPM II variables and survival status at hospital discharge have been collected. Performance of the severity systems was assessed by evaluating calibration and discrimination. Logistic regression was used to customize the MPM II(24) and SAPS II indexes. Discrimination was high enough for all of the models. However, calibration of the MPM II(24) was not as satisfactory as for the other models. The MPM II(24) and SAPS II were both reduced to five variables (MPM II(24 cor:) age, PaO2, continuous vasoactive drugs, urinary output, and mechanical ventilation; SAPS II(cor:) age, PaO2/FI(O2) ratio, systolic BP, Glasgow coma score, and urinary output). Both models showed better calibration and discrimination than the original ones.

CONCLUSIONS

Prognostic indexes developed for multidisciplinary patients show good performance when applied to patients with acute myocardial infarction, but customization can reduce the number of variables necessary to compute them without a loss of, and a possible improvement in, prognostic accuracy.

Percutaneous dilatational cricothyroidotomy: outcome with 44 consecutive patients

OBJECTIVE

To assess the value of the percutaneous dilatational technique in elective cricothyroidotomy.

DESIGN

Forty-four consecutive patients requiring prolonged mechanical ventilation.

SETTING

The general 14-bed intensive care unit of a university hospital.

INTERVENTIONS

Fourty-four percutaneous dilatational cricothyroidotomies using a multiple-dilator wire-guided procedure.

MEASUREMENTS AND RESULTS

The average duration for the procedure was 11 min in 37 patients. No significant complications occurred intraoperatively except for one paratracheal cannula insertion. Postoperative complications were one case of stoma infection, three cases of transient phonatory changes, two cases of a small peristomal granuloma, and one case of persistent stoma. Of 21 decannulated patients, 16 survived to discharge. Long-term follow-up was possible in 14 surviving patients. All were asymptomatic several months after decannulation.

CONCLUSIONS

Percutaneous dilatational cricothyroidotomy can be a quick, safe technique, as good as the percutaneous subcricoidal approach in ventilated, critically ill patients.

Statistical modeling of prognostic indices for evaluation of critically ill patients

OBJECTIVE

To identify the most predictive association of variables from the usual indices of severity of illness by statistical objective analysis.

DESIGN

Logistic regression analysis of the different variables of the most important indices.

SETTING

A general critical care medicine group practice in a university hospital.

PATIENTS

A total of 630 critical care patients age 12 to 87 yrs were evaluated. The most important indices of severity of illness and the corresponding variables were recorded and the patient's course was followed for 3 months after ICU admission.

MEASUREMENTS AND MAIN RESULTS

One of our hypotheses was that the inclusion of an excessive number of variables to obtain the most common prognostic indices of mortality in critical care patients results in an underestimation of mortality and a redundancy of prognostic information. We performed a logistic regression analysis using the variables of the currently used indices of critical care prognosis: Acute Physiology Score, Simplified Acute Physiology Score, Acute Physiology Score-II, and Mortality Prediction Model. This mathematical approach resulted in a model of five variables: organ system failure, blood glucose, serum calcium, serum prothrombin activity, and serum osmolality. The score obtained from this model gave accurate prognostic criteria:sensitivity 91.2% and specificity 90%, using a cutoff point of 0.7; sensitivity 86% and, specificity 94%, using a cutoff point of 0.5.

CONCLUSIONS

Our results show that suitable statistical management of the discriminant prognostic variables allows reduction of the number of variables of the severity indices currently used, obtaining five more predictive variables.