Purpose of review

Recent findings

Summary

Symptom Experiences of Family Members of Intensive Care Unit Patients at High Risk of Dying

ABSTRACT

Objective: To describe the symptom experiences of family members of patients at high risk of dying in the intensive care unit and to assess risk factors associated with an increase in symptoms. Design: Prospective, cross-sectional, descriptive study. Setting: Three intensive care units at a tertiary medical center in the Western United States. Participants: A convenience sample of 74 family members of 74 ICU patients at high risk of dying participated in the study. Interventions: None. Measurements and Results: We assessed the results from several reliable and valid instruments of 74 family members 3-5 days after the patient's admission to the ICU. Overall the prevalence of symptoms was high, with over 56.8% of our sample having symptoms of traumatic stress, 79.7% having symptoms of anxiety and 70.3% having symptoms of depression. We also found that family members suffered from other symptoms such as tired, sadness, and poor appetite at moderate to severe levels of distress. Independent factors associated with an increase in severity of family members' symptoms included younger patient age, younger family member age, female gender of the family, and family member's race other than White. In addition, we found that the majority of the family members were coping and functioning at high levels during the ICU experience. Conclusions: Family members are important to patient care in the ICU. They are often required to participate in end of life decision making for the patient at high risk of dying. Family members in our study had high levels of psychological and physical symptoms, often at distressing levels. More support and understanding of family members' symptom experiences is needed in order to understand the long term effects of symptoms and to improve family centered care in the ICU.

The Use of Transesophageal Echocardiography for the Assessment of Left Ventricular Volume and Function in Patients Undergoing Acute Normovolemic Hemodilution as a Human Hemorrhagic Model BACKGROUND: Since the development of the sphygmomanometer in 1896, the several methods to monitor volume resuscitation in hypovolemic trauma patients have been examined. Recently, transesophageal echocardiography (TEE) has been considered for this use. PURPOSE: This study examined the use of TEE for the assessment of left ventricular volume and function during graded blood removal in a human hemorrhagic model. DESIGN: Following IRB approval, 38 patients undergoing acute normovolemic hemodilution (ANH) intraoperatively were consented to have 15% of their total blood volume removed (according to ANH protocol) in 5% aliquots and stored in the operating room for re-infusion. After blood withdrawal, 5% aliquots of Hextend® was infused, equal the amount of blood removed. Left ventricular (LV) chamber dimensions and trans-mitral Doppler flow measurements were obtained with TEE at baseline and at each blood withdrawal and replacement of Hextend®. LV measurements analysis included: one-dimensional (1D) end-diastolic diameter (EDD), end-systolic diameter (ESD), and fractional shortening (FS); two-dimensional (2D) end-diastolic area (EDA), end-systolic area (ESA), and fractional area change (FAC); three-dimensional (3D) end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF); trans-mitral Doppler flow measurements of E and A-wave morphology. RESULTS: Statistically significant differences were demonstrated for measurements of: 1D EDD (p < .0001) and ESD (p < .0001); 2D EDA (p < .0001) and ESA (p < .0001) during blood removal. No statistically significant differences were observed for FS (p = .371) or FAC (p = .369). Statistically significant differences were demonstrated for 3D measurements of EDV (p < .0001) and EF (p = .002) during both blood removal and replacement with Hextend®. No statistical significance was observed with ESV measurements (p = .427). Only the trans-mitral Doppler measurement of peak E-wave velocity demonstrated a statistically significant difference (p < .0001). CONCLUSION: Although all measurements of LV dimensions can detect 5% changes during blood removal, 3D measurements of EDV and EF can detect changes during both blood removal and replacement of Hextend®, possibly making it better at guiding volume replacement during blood loss. Trans-mitral Doppler flow may not be as effective as a guide for fluid management.

Delirium is a pervasive complication of critical illness that increases patient morbidity and mortality. This exploratory study examined associations between delirium, thiamine blood levels, genes associated with thiamine metabolism and other genes identified as having an association with delirium in critically ill patients.

Fifty mechanically ventilated ICU patients were enrolled in this prospective observational study between June 2009 and June 2010. Blood thiamine levels and delirium status were assessed daily. A blood sample for genotyping was obtained at baseline.

Thiamine blood levels are highly variable in critical illness; 56% of the variance in thiamine levels derives from differences between individuals. The remaining 44% of the variance comes from differences in the within-patient trajectory over days.

Whole blood thiamine levels were not asociated with delirium in critical illness. There was evidence of a genetic association with delirium. This study warrants replication with a larger number of pateints to validate this finding.

Fever in critically ill adults: monitoring, management, and outcomes

Fever is a common occurrence in intensive care unit (ICU) patients and is routinely treated with antipyretic therapies. Evidence to inform guidelines for fever management in ICUs is limited due to the low level of evaluable data. The introduction (Chapter 1) provides the background and significance of fever management in ICU patients. The question of whether fever should be suppressed based on its impact on outcomes in all ICU patients or in specific subpopulations, such as sepsis, neurological injury, and acute respiratory distress syndrome (ARDS), remains unanswered. To describe the impact of fever on outcomes of ICU patients with ARDS, a secondary analysis was completed and found that early in the ARDS trajectory, fever is associated with improved survival rates (Chapter 2).

A common limitation of studies investigating body temperature alterations in ICU patients is the lack of standard measurement of core body temperature. To address this limitation for the primary clinical trial of this dissertation and to evaluate a prospective continuous core temperature monitoring device for use in ICU patients, a method-comparison study was completed (Chapter 3). This method-comparison study tested the agreement and precision of a novel technology for continuous thermometry with standard thermometry methods in febrile ICU patients.

Fever suppression remains widespread and acetaminophen is the most common first line therapy used by ICU clinicians. There is a lack of high-grade evidence about the antipyretic efficacy and the acute hemodynamic effects of the more recently available intravenous (IV) formulation of acetaminophen in ICU patients. To better understand the therapy response and potential acute adverse effects of this commonly administered medication in febrile critically ill patients, a randomized, double blind, placebo-controlled trial to evaluate the effect of IV acetaminophen on body temperature and hemodynamic responses was conducted (Chapter 4).