Does Hypoxia Affect Intensive Care Unit Delirium or Long-Term Cognitive Impairment After Multiple Trauma Without Intracranial Hemorrhage?

Division of Trauma and Surgical Critical Care, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
The Journal of trauma (Impact Factor: 2.96). 04/2011; 70(4):910-5. DOI: 10.1097/TA.0b013e3182114f18
Source: PubMed

ABSTRACT Within the traumatic brain injury population, outcomes are affected by hypoxic events in the early injury period. Previous work shows a high prevalence of cognitive deficits in patients with multiple injuries who do not have intracranial hemorrhage identified on admission head computed tomography scan. We hypothesize that intensive care unit (ICU) delirium and long-term cognitive impairment (LTCI) are more likely in patients who have a hypoxic event within the first 48 hours of ICU admission.
A total of 173 patients with multiple injuries (Injury Severity Score [ISS] >15) who presented to a Level I trauma center from July 2006 to July 2007 were enrolled in a study on long-term cognitive deficit. Ninety-seven patients required ICU management and all had continuous oxygen saturation data collected. The Confusion Assessment Method for the ICU was collected twice a day on all patients in ICU. Of the total enrolled population, 108 (62%) were evaluated 12 months after discharge by neuropsychological tests. Cognitive impairment was defined as having 2 neuropsychological test scores, 1.5 standard deviations below the mean or 1 neuropsychological test score, and 2 standard deviations below the mean. Demographic data, ISS, initial 24-hour blood requirements, presence of hypoxia (SpO(2) <90% and <85%) or hypotension (systolic blood pressure <90 mm Hg), emergency department (ED) pulse, Glasgow Coma Scale score, ventilator and ICU days were recorded. Significant univariate identification of clinical variables was used for multivariate analysis.
Fifty-five of 97 ICU patients (57%) were Confusion Assessment Method-ICU positive for delirium and 59 of 108 (55%) demonstrated cognitive impairment at 12-month follow-up. There was no significant association between hypoxia and ICU delirium (74.5% vs. 74%; p = 0.9) or LTCI (89% vs. 83%; p = 0.5). Ventilator days (8.7 ± 8.9 vs. 2.9 ± 4.6; p < 0.0001), ED pulse (109 ± 28.5 vs. 94 ± 22.8; p = 0.01), and blood transfusions (10 U ± 10.8 U vs. 5 U ± 5.3 U; p = 0.015) were significant independent predictors of delirium. Ventilator days (odds ratio, 1.16; 95% confidence interval, 1.05-1.29; p = 0.004) and ED pulse (odds ratio, 1.02; 95% confidence interval, 1.00-1.04; p = 0.03) remained significant predictors of ICU delirium after adjusting for ISS, hypoxic state, blood transfusions, and ED blood pressure. Among ED Glasgow Coma Scale score (10.5 ± 5.1 vs. 11.4 ±5.5; p = 0.7), ISS (33.3 ± 10.1 vs. 32.2 ± 9.0; p = 0.5), ventilator days (6.5 ± 7.5 vs. 6.2 ± 8.8; p = 0.4), blood transfusions (8.1 ± 6.8 vs. 9.4 ± 8.1; p = 0.4), and delirium (62% vs. 62.5%; p = 0.9), there were no significant univariate associations with LTCI.
Hypoxic events in the ICU do not have a direct correlation with ICU delirium or LTCI in the patients with multiple injuries without evidence of intracranial hemorrhage.

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Available from: Kristin Archer, Nov 18, 2014
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    • "It is important to note that most mechanically ventilated ICU patients are not hypoxemic and may have not been hypoxemic at the time of intubation; the implication that hypoxemia is a common trigger of ICU or perioperative delirium is not based on robust clinical evidence. (7). "
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    ABSTRACT: Delirium is prevalent among intensive care unit patients. It prolongs length of stay, increases costs, and is independently associated with higher mortality rates. While its specific biological pathways are largely unknown, environmental and iatrogenic determinants have been repeatedly recognized. Removal of the known triggers and pharmacologic intervention constitute available therapies. This review focuses on the clinical significance of delirium in critically ill patients, from its prevalence to its long-term impact, the ways that we have to diagnose it, and the available therapeutic options.
    01/2012; 2:1-9.
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    • "There are causes like cerebral trauma, especially involving loss of consciousness, postcontussive states, hemorrhage, vascular abnormalities, subarachnoid hemorrhage, brain infection, transitory ischemic attacks, neoplasma (primary or metastatic), dementia, stroke, and hypertensive encephalopathy (Maldonado 2000a, Guillamondegui et al 2011). "
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    ABSTRACT: Delirium is a common event in the hospitalized surgical patiens. The pathophysiology of delirium is incompletely understood yet, but numerous risk factors for the development of delirium have been already identified. A literature review was performed using the National Library of Medicine PubMed data-base and Web of Science, including all resources within the period 1991–2011, additional references were found through bibliography reviews of relevant articles. The key word "delirium" with the following terms:"intensive care unit","antipsychotics", "benzodiaz-epine", "opioids", "elderly", "management". Constraints limiting time period of publications or their language were not applied. Reference lists of publications identified by these procedures were hand-searched for additional relevant references. Delirium in the ICU (intensive care unit) is not only a frightening experience for the patient and his or her family; it is also a challenge for the nurses and physicians taking care of the patient. Furthermore, it is also associated with worse outcome, prolonged hospitalisation, increased costs, long-term cognitive impairment and higher mortality rates. Predisposing factors, such as age, impairment, and nature and severity of comorbidity, increase the risk of experiencing delirium during hospitalization. The management of delirium involves the concurrent search for and treatment of the underlying aetiology while actively controlling the symptoms of delirium. Antipsychotics are demonstrating efficacy in controlling the symptoms of delirium with less extrapyramidal side effects. Proper diagnosis and treatment is important in the medical setting and significantly decreases the burden on the patient, caregivers, and medical system.
    Activitas Nervosa Superior Rediviva 01/2011; 53(53):121-133.
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    ABSTRACT: Delirium is frequently encountered in the ICU and is associated with significant adverse outcomes. The increasingly recognized consequences of ICU delirium should enhance efforts to improve recognition and management of this serious problem. We aim to review the recent literature on ICU delirium, including risk factors, detection, management and long-term impact of disease. We present the most recent evidence on risk factors for ICU delirium and its persistence. In addition, we aim to clarify some of the confusion surrounding the tools for detection and their limitation in practice. The literature reflects long-term neurocognitive impairments following ICU delirium and supports efforts to reduce these negative outcomes using protocol-driven sedation and ventilator management. Although haloperidol is widely accepted as the preferred pharmacologic treatment for delirium, its use is not seeded in robust evidence. Limited studies reflect the safety of atypical antipsychotics for treatment but lack clear improvement in delirium-related outcomes. We place an emphasis on the use of protocols to reduce the use of sedatives, particularly benzodiazepines in the management of ICU delirium. Delirium remains an underrecognized and underdiagnosed problem. Detection tools are readily available and easy to use. Further understanding of risk factors is needed to identify most susceptible individuals and plan management, which should include prevention and therapy based on available evidence.
    Current opinion in critical care 04/2012; 18(2):146-51. DOI:10.1097/MCC.0b013e32835132b9 · 2.62 Impact Factor
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