Mechanical ventilator support and the resumption of spontaneous ventilation or weaning create significant alterations in alveolar and intrathoracic pressure that influence thoracic blood volume and flow. Compensatory autonomic tone alterations occur to ensure adequate tissue oxygen delivery, but autonomic responses may produce cardiovascular dysfunction with subsequent weaning failure. The authors describe autonomic responses of critically ill patients ( n = 43) during a 24-hr period of mechanical ventilatory support and during the 24 hr that included their initial spontaneous breathing trial using continuous positive airway pressure. Nearly two thirds of these patients demonstrated abnormal autonomic function and this dysfunction was more severe in those patients who were unable to sustain spontaneous ventilation ( n = 15). With further systematic study, autonomic responses may be useful in the identification of patients who are likely to develop cardiac dysfunction with the resumption of spontaneous breathing.
Comorbid chronic obstructive pulmonary disease is found in approximately one-third of patients with heart failure. Survival in patients with chronic obstructive pulmonary disease generally decreases as lung function declines. However, the association between lung function, hospitalization and survival is less clear for patients with heart failure.The purpose of this study was to determine the predictive power of spirometry measures for event-free survival (combined all-cause hospitalization and/or mortality) in patients with heart failure.In this secondary analysis of data from three prospective, longitudinal studies, we selected patients with a confirmed diagnosis of heart failure who completed airflow limitation assessment using spirometry measures ( n=137): forced vital capacity, forced expiratory volume/second, and forced expiratory volume/second/forced vital capacity. Cox proportional hazards modeling was used to determine the relationship between spirometry and all-cause hospitalization/mortality with and without adjusting for demographic and clinical covariates over a four-year follow-up period.A majority (74%) exhibited some degree of airflow limitation (forced expiratory volume/second<80% predicted value) and 26 (19%) met the spirometric criterion for chronic obstructive pulmonary disease (forced expiratory volume/second/forced vital capacity⩽0.70). Cox proportional hazards regression models compared all-cause hospitalization/mortality between those with and without airflow limitation. Patients with airflow limitation were 2.2 times more likely to be hospitalized or die compared to those without airflow limitations (hazard ratio: 2.20, 95% confidence interval 1.06-4.53, p=0.03).Patients with comorbid heart failure and airflow limitation were at more than double the risk for an event. Spirometric measures may be useful to patients with heart failure, as tailored management of airflow limitation may impact event-free survival.
Transfusion of blood components is often required in resuscitation of patients with major trauma. Packed red blood cells and platelets break down and undergo chemical changes during storage (known as the storage lesion) that lead to an inflammatory response once the blood components are transfused to patients. Although some evidence supports a detrimental association between transfusion and a patient’s outcome, the mechanisms connecting transfusion of stored components to outcomes remain unclear. The purpose of this review is to provide critical care nurses with a conceptual model to facilitate understanding of the relationship between the storage lesion and patients’ outcomes after trauma; outcomes related to trauma, hemorrhage, and blood component transfusion are grouped according to those occurring in the short-term (≤30 days) and the long-term (>30 days). Complete understanding of these clinical implications is critical for practitioners in evaluating and treating patients given transfusions after traumatic injury.
Medication adherence and perceived social support (PSS) are independent predictors of mortality in patients with heart failure (HF). However, the predictive power of the combination of medication adherence and PSS for hospitalization and death has not been investigated in patients with HF. The purpose of the study was to explore the combined influence of medication adherence and PSS for prediction of cardiac event-free survival in patients with HF.A total of 218 HF patients monitored medication adherence for 1-3 months and completed the Multidimensional Perceived Social Support Scale (MPSSS) at baseline. Medication adherence was measured using a valid and objective measure, the Medication Event Monitoring System (MEMS). Patients were followed for up to 3.5 years to collect data about cardiac event-free survival (i.e., cardiac emergency department visits, hospitalizations, and death). To test the association of the combination of medication adherence and PSS with outcomes, the interaction term of medication adherence and PSS was first entered in a Cox regression to predict outcomes. Second, patients were grouped using an evidence-based cutpoint of 88% for medication adherence from the MEMS data and a median score 71 of the MPSSS. Kaplan-Meier and Cox proportional hazards models were used to compare cardiac event-free survival among groups.Medication adherence and PSS were independent predictors of cardiac event-free survival (p = .006 and .021, respectively). Patients with medication nonadherence and lower PSS had a 3.5 times higher risk of cardiac events than those who were adherent and had higher PSS.Medication adherence mediated the relationship between PSS and cardiac event-free survival in this sample. Moreover, medication adherence and social support independently, and in combination, predicted cardiac event-free survival in patients with HF. Interventions to improve clinical outcomes should address medication adherence and social support.
Recently, clinical and research attention has been focused on refining weaning processes to improve outcomes for critically ill patients who require mechanical ventilation. One such process, use of a weaning protocol, has yielded conflicting results, arguably because of the influence of existing context and processes.To compare international data to assess differences in context and processes in intensive care units that could influence weaning.Review of existing national data on provision of care for critically ill patients, including structure, staffing, skill mix, education, roles, and responsibilities for weaning in intensive care units of selected countries.Australia, New Zealand, Denmark, Norway, Sweden, and the United Kingdom showed similarities in critical care provision, structure, skill mix, and staffing ratios in intensive care units. Weaning in these countries is generally a collaborative process between nurses and physicians. Notable differences in intensive care units in the United States were the frequent use of an open structure and inclusion of respiratory therapists on the intensive care unit's health care team. Nurses may be excluded from direct management of ventilator weaning in some institutions, as this role is primarily assumed by respiratory therapists guided by medical directives. Availability of critical care beds was highest in the United States and lowest in the United Kingdom.Context and processes of care that could influence ventilator weaning outcomes varied considerably across countries. Further quantification of these contextual influences should be considered when translating research findings into local clinical practice and when designing randomized controlled trials.
Background More than 22% of individuals with diabetes mellitus have concomitant heart failure (HF), and the prevalence of diabetes in those with HF is nearly triple that of individuals without HF. Comorbid depressive symptoms are common in diabetes and HF. Depressive symptoms are an independent predictor of mortality in individuals with diabetes alone, as well as those with HF alone and are a predictor of rehospitalization in those with HF. However, the association of comorbid HF, diabetes and depressive symptoms with all-cause mortality and rehospitalization for cardiac causes has not been determined. Objective The purpose of this study was to evaluate the association of comorbid HF, diabetes and depression with all-cause mortality and rehospitalization for cardiac cause. Method Patients provided data at baseline about demographic and clinical variables and depressive symptoms; patients were followed for at least 2 years. Participants were divided into four groups based on the presence and absence of diabetes and depressive symptoms. Cox regression analysis was used to determine whether comorbid diabetes and depressive symptoms independently predicted all-cause mortality and cardiac rehospitalization in these patients with HF. Results Patients (n=663) were primarily male (69%), white (76%), and aged 61±13 years. All-cause mortality was independently predicted by the presence of concomitant diabetes and depressive symptoms (HR 3.71; 95% CI 1.49 to 9.25; p=0.005), and depressive symptoms alone (HR 2.29; 95% CI 0.94 to 5.40; p=0.05). The presence of comorbid diabetes and depressive symptoms was also an independent predictor of cardiac rehospitalization (HR 2.36; 95% CI 1.27 to 4.39; p=0.007). Conclusions Comorbid diabetes and depressive symptoms are associated with poorer survival and rehospitalization in patients with HF; effective strategies to regularly evaluate and effectively manage these comorbid conditions are necessary to improve survival and reduce rehospitalization rates.
Background: Impaired psychological state, such as anxiety and depressive symptoms, occurs in up to 40% of patients hospitalized for traumatic injury. These symptoms, in the acute period, may delay engagement in activity, such as ambulation, following injury. The purpose of this study was to determine whether baseline anxiety and depressive symptoms predicted delayed (>48 hr from admission) ambulation in patients hospitalized for major traumatic injury. Methods: Adults ( n = 19) admitted for major trauma (Injury Severity Score [ISS] = 15) provided a baseline measure of anxiety and depressive symptoms (Hospital Anxiety and Depression Scale [HADS]). Logistic regression was used to determine the predictive power of baseline HADS Anxiety and HADS Depression subscale scores for delayed ambulation while controlling for ISS. Results: At baseline, anxiety was present in 32% of patients; 21% reported depressive symptoms. Baseline HADS Anxiety score did not predict the ambulation group. However, for each 1 point increase in baseline HADS Depression score, the likelihood of patients ambulating after 48 hr from admission increased by 67% (odds ratio = 1.67; 95% CI [1.02, 2.72]; p = .041). Conclusion: Worsening depressive symptoms were associated with delayed ambulation in the acute period following injury. Future, larger scale investigations are needed to further elucidate the relationship between psychological symptoms and the acute recovery period from trauma to better inform clinicians and guide development of interventions to improve patient outcomes.
