Surgical Intensive Care Unit Setting Research Articles

Association of COVID-19 Visitor Limitations and Goals of Care Discussions in the Intensive Care Unit

IntroductionThe COVID-19 pandemic led to visitor restrictions in many hospitals. Since care in the surgical intensive care unit (SICU) often engages visitors as surrogate decision-makers, we investigated whether there was an association between COVID-19–related visitor restrictions, goals of care discussions (GOCD), and patient outcomes in SICU patients. MethodsWe conducted a retrospective review of trauma and emergency general surgery (EGS) patients admitted to a rural tertiary SICU between July 2019 and April 2021, dividing patients into those admitted during COVID-19 visitor restrictions and those admitted at other times. Using univariate and multivariate logistic regression analyses, we compared the primary outcome, incidence of GOCD, and incidence of prolonged hospital (> 14 d) and intensive care unit length of stay (LOS, > 7 d) between the two groups. ResultsOne hundred seventy nine of 368 study patients (48.6%) presented during restricted visitation. The proportion of GOCD was 38.0% and 36.5% in the restricted and nonrestricted visitation cohorts, respectively (P = 0.769). GOCD timing and outcomes were similar in both groups. The use of telecommunication increased during restricted visitation, as did the proportion of trauma patients admitted to the SICU. On multivariable logistic regression, age and patient category were independent predictors of GOCD. On outcomes analysis, visitor restriction was associated with prolonged hospital LOS for EGS patients (odds ratio 2.44, 95% confidence interval 1.01-5.91, P value 0.048). ConclusionsRestricted visitation was not associated with changes in frequency or outcome of GOCD, but was associated with prolonged hospital LOS among EGS patients who had SICU admissions. Further investigation of patient/surrogate satisfaction with virtual GOCD in the SICU setting is needed.

Defining conditions for effective interdisciplinary care team communication in an open surgical intensive care unit: a qualitative study

ObjectivePoor interdisciplinary care team communication has been associated with increased mortality. The study aimed to define conditions for effective interdisciplinary care team communication.DesignAn observational cross-sectional qualitative study.SettingA surgical intensive care...

Delirium severity does not differ between medical and surgical intensive care units after adjusting for medication use

Severe delirium is associated with an increased risk of mortality, institutionalization, and length of stay. Few studies have examined differences in delirium severity between different populations of critically ill patients. The objective of the study was to compare delirium severity and the presence of the four core features between adults in the surgical intensive care unit (SICU) and medical intensive care unit (MICU) while controlling for variables known to be associated with delirium. This is a secondary analysis of two parallel randomized multi-center trials conducted from March 2009 to January 2015 at 3 Indianapolis hospitals. A total of 474 adults with delirium were included in the analysis. Subjects were randomized in a 1:1 ratio in random blocks of 4 by a computer program. Patients were randomized to either haloperidol prescribing or de-prescribing regimen vs usual care. Delirium severity was assessed daily or twice-daily using the CAM-ICU-7 beginning after 24 h of ICU admission and until discharge from the hospital, death, or 30 days after enrollment. Secondary outcomes included hospital length of stay, hospital and 30-day mortality, and delirium-related adverse events. These outcomes were compared between SICU and MICU settings for this secondary analysis. Out of 474 patients, 237 were randomized to intervention. At study enrollment, the overall cohort had a mean age of 59 (SD 16) years old, was 54% female, 44% African-American, and 81% were mechanically ventilated upon enrollment. MICU participants were significantly older and severely ill with a higher premorbid cognitive and physical dysfunction burden. In univariate analysis, SICU participants had significantly higher mean total CAM-ICU-7 scores, corresponding to delirium severity, (4.15 (2.20) vs 3.60 (2.32), p = 0.02), and a lower mean RASS score (− 1.79 (1.28) vs − 1.53 (1.27), p < 0.001) compared to MICU participants. Following adjustment for benzodiazepines and opioids, delirium severity did not significantly differ between groups. The presence of Feature 3, altered level of consciousness, was significantly associated with the SICU participants, identifying as Black, premorbid functional impairment, benzodiazepines, opioids, and dexmedetomidine. In this secondary analysis examining differences in delirium severity between MICU and SICU participants, we did not identify a difference between participant populations following adjustment for administered benzodiazepines and opioids. We did identify that an altered level of consciousness, core feature 3 of delirium, was associated with SICU setting, identifying as Black, activities of daily living, benzodiazepines and opioid medications. These results suggest that sedation practice patterns play a bigger role in delirium severity than the underlying physiologic insult, and expression of core features of delirium may vary based on individual factors.Trial registration CT#: NCT00842608.

End of Life Care and Withdrawal of Life Support

Despite advances in critical care medicine and resuscitation, many patients who are admitted to the intensive care unit (ICU) will ultimately die. Although outcomes may be better for surgical rather than medical ICU patients, addressing the end of life is a fundamental and necessary aspect of critical care for all patients. Over the last few years, we have increasingly recognized the role of palliative care in the surgical and trauma ICU. Palliative medicine in the surgical ICU setting results in decreased length of stay, improved communication with family and patients, and earlier identification of goals of care. This review covers indications for palliative care consultation, practical considerations at the end of life, withdrawal of mechanical ventilation, and symptoms and symptom management at the end of life. Tables list the American College of Surgeons statement on the principles guiding care at the end of life, guidelines for palliative care consultation in the surgical ICU, ABCDs of dignity-conserving care, palliative care principles on transitioning a patient to comfort measures only, and the process of withdrawing ventilatory support. This review 5 tables, and 33 references. Key words: comfort measures; end of life; intensive care unit end-of-life care; palliation; palliative care; palliative care consultation; palliative medicine; quality of dying; withdrawal of life support

End of Life Care and Withdrawal of Life Support

Despite advances in critical care medicine and resuscitation, many patients who are admitted to the intensive care unit (ICU) will ultimately die. Although outcomes may be better for surgical rather than medical ICU patients, addressing the end of life is a fundamental and necessary aspect of critical care for all patients. Over the last few years, we have increasingly recognized the role of palliative care in the surgical and trauma ICU. Palliative medicine in the surgical ICU setting results in decreased length of stay, improved communication with family and patients, and earlier identification of goals of care. This review covers indications for palliative care consultation, practical considerations at the end of life, withdrawal of mechanical ventilation, and symptoms and symptom management at the end of life. Tables list the American College of Surgeons statement on the principles guiding care at the end of life, guidelines for palliative care consultation in the surgical ICU, ABCDs of dignity-conserving care, palliative care principles on transitioning a patient to comfort measures only, and the process of withdrawing ventilatory support. This review 5 tables, and 33 references. Key words: comfort measures; end of life; intensive care unit end-of-life care; palliation; palliative care; palliative care consultation; palliative medicine; quality of dying; withdrawal of life support

Impact of the Chelsea critical care physical assessment (CPAx) tool on clinical outcomes of surgical and trauma patients in an intensive care unit: An experimental study.

BackgroundCritically ill patients following traumatic injury or major surgery are at risk of loss of skeletal muscle mass, which leads to decreased physical function. Early rehabilitation in an intensive care unit (ICU) is thought to preserve or restore physical functioning. The Chelsea critical care physical assessment (CPAx) is a measurement tool used to assess physical function in the ICU.ObjectivesTo determine whether the use of the CPAx tool as part of physiotherapy patient assessment, in two adult trauma and surgical ICU settings where early patient mobilisation forms part of standard physiotherapy practice, had an impact on ICU and hospital length of stay (LOS) through delivery of problem-oriented treatment plans.MethodA single-centred pre–post quasi-experimental study was conducted. The population was a consecutive sample of surgical and trauma ICU patients. Participants’ functional ability was assessed with the CPAx tool on alternative days during their ICU stay, and rehabilitation goals were modified according to their CPAx score. Intensive care unit and hospital LOS data were collected and compared to data of a matched historical control group. Descriptive and inferential statistics were used.ResultsA total of 26 ICU patients were included in the intervention group (n = 26). They received CPAx-guided therapy, and outcomes were matched with ICU patients in the historical control group (n = 26). The median sequential organ failure assessment (SOFA) score was significantly higher in the control group (p = 0.005) (3.5 [IQR 2–6.3]) versus (2 [IQR 1.8–2.5]) for the intervention group. The median admission CPAx score for the intervention group was 33.5 (IQR 16.1–44), and the median ICU discharge score was 38 (IQR 28.5–43.8). No significant differences were found in ICU days (control 2.7 [IQR 1.1–5.2]; intervention 3.7 [IQR 2.3–5.4]; p = 0.27) or hospital LOS (control 13.5 [IQR 9.3–18.3]; intervention 11.4 [IQR 8.4–20.3], p = 0.42). Chelsea critical care physical assessment scores on ICU admission had a moderate negative correlation with hospital LOS (r = −0.58, p = 0.00, n = 23). Chelsea critical care physical assessment scores at ICU discharge had strong positive correlation with discharge SOFA scores (r = 0.7; p = 0.025; n = 10).ConclusionProblem-oriented patient rehabilitation informed by the CPAx tool resulted in improvement of physical function but did not reduce ICU or hospital LOS.Clinical implicationsA higher level of physical function at ICU admission, measured with CPAx, was associated with shorter hospital LOS.

Factor XIII Deficiency and Thrombocytopenia Are Frequent Modulators of Postoperative Clot Firmness in a Surgical Intensive Care Unit

Objective: Fibrinogen and factor XIII (FXIII) have been shown to critically influence clot firmness in the intraoperative setting and thus likely influence intraoperative bleeding. We were interested to identify potential modulators of postoperative clot firmness in a tertiary care hospital surgical intensive care unit setting, independent of their clinical course during surgery. Methods: 272 day-shift consecutive patients were evaluated for whole blood clot firmness evaluated by the ROTEM® EXTEM thrombelastometric assay and various potential modulators of clot firmness upon arrival at the surgical intensive care unit (SICU). Results: Maximum clot firmness on the SICU was found to be independently influenced by the amount of colloids given during surgery as well as by platelet count, fibrinogen concentration, and FXIII activity at the time of SICU admission. In patients with lowest clot firmness, FXIII activity was the most important independent modulator of clot firmness; in patients with the highest clot firmness, platelet count and fibrinogen concentration were the most important modulators of clot firmness. Deficiencies (i.e., results below normal range) of these modulators of clot firmness were most prevalent for FXIII (activity < 70%: 45% of cases), which was significantly more frequent than thrombocytopenia (<150 × 10⁹/l: 32%) or fibrinogen deficiency (<1.5 g/l: 6%). Conclusions: Postoperative clot firmness as evaluated by whole blood thrombelastometry (ROTEM EXTEM assay) is independently and frequently modulated though FXIII activity and the platelet count, while fibrinogen concentration is also an independent but much less frequent modulator. Different modulators show different influences, depending on the clot firmness being present. Colloids infused during surgery also independently modulate postoperative clot firmness. Based on our data, strategies can be developed to improving postoperative care of patients with bleedings or at risk for bleeding.

Validity and reliability of the Thai version of the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU).

PurposeThe purpose of this study was to determine the validity and reliability of the Thai version of the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU), when compared to the diagnoses made by delirium experts.Patients and methodsThis was a cross-sectional study conducted in both surgical intensive care and subintensive care units in Thailand between February–June 2011. Seventy patients aged 60 years or older who had been admitted to the units were enrolled into the study within the first 48 hours of admission. Each patient was randomly assessed as to whether they had delirium by a nurse using the Thai version of the CAM-ICU algorithm (Thai CAM-ICU) or by a delirium expert using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision.ResultsThe prevalence of delirium was found to be 18.6% (n=13) by the delirium experts. The sensitivity of the Thai CAM-ICU’s algorithms was found to be 92.3% (95% confidence interval [CI] =64.0%−99.8%), while the specificity was 94.7% (95% CI =85.4%−98.9%). The instrument displayed good interrater reliability (Cohen’s κ =0.81; 95% CI =0.64−0.99). The time taken to complete the Thai CAM-ICU was 1 minute (interquatile range, 1−2 minutes).ConclusionThe Thai CAM-ICU demonstrated good validity, reliability, and ease of use when diagnosing delirium in a surgical intensive care unit setting. The use of this diagnostic tool should be encouraged for daily, routine use, so as to promote the early detection of delirium and its rapid treatment.

An Interprofessional Approach to Reducing the Overutilization of Stress Ulcer Prophylaxis in Adult Medical and Surgical Intensive Care Units

Overutilization of stress ulcer prophylaxis (SUP) in the intensive care unit (ICU) is common. Acid-suppressive therapies routinely used for SUP are best reserved for patients with greatest risk of clinically important bleeding as they have been associated with nosocomial pneumonia, Clostridium difficile infection and increased hospital cost. The primary objective was to reduce inappropriate utilization of SUP in 2 adult medical and surgical ICU settings at the University of California, San Francisco Medical Center. Secondary objectives included reduction of inappropriate continuation of SUP at ICU and hospital discharge. To attain the study objective, an interprofessional team developed a bundled quality improvement initiative, including an institution SUP guideline, pharmacist-led intervention, and an education and awareness campaign. To assess the impact of these interventions, we conducted a retrospective cohort study comparing data on prescribing practices at baseline before and after the intervention. Since computerized prescriber order entry (CPOE) was implemented during this time frame, preintervention data collection consisted of 2 periods, one before and one after CPOE implementation. The incidence of the inappropriate use of SUP was not significantly different between the pre-CPOE and post-CPOE groups (20 and 19 per 100 patient-days, respectively; P = .88), but the incidence of inappropriate use of SUP was significantly lower in the postintervention group versus the post-CPOE group (9 and 19 per 100 patient-days, respectively; P = .03). At ICU discharge, 4% of patients in the post-intervention group were discharged inappropriately on SUP compared with 8% in the post-CPOE group (P = .54). At hospital discharge, none of the patients in the postintervention group were discharged inappropriately on SUP compared with 7% in the post-CPOE group (P = .22). Implementation of an interprofessional bundled quality improvement initiative is effective in decreasing inappropriate use of SUP in adult medical and surgical ICUs at a university-affiliated, tertiary care academic medical center.

Evaluation of a Model for Glycemic Prediction in Critically Ill Surgical Patients

We evaluated a neural network model for prediction of glucose in critically ill trauma and post-operative cardiothoracic surgical patients. A prospective, feasibility trial evaluating a continuous glucose-monitoring device was performed. After institutional review board approval, clinical data from all consenting surgical intensive care unit patients were converted to an electronic format using novel software. This data was utilized to develop and train a neural network model for real-time prediction of serum glucose concentration implementing a prediction horizon of 75 minutes. Glycemic data from 19 patients were used to “train” the neural network model. Subsequent real-time simulated testing was performed in 5 patients to whom the neural network model was naive. Performance of the model was evaluated by calculating the mean absolute difference percent (MAD%), Clarke Error Grid Analysis, and calculation of the percent of hypoglycemic (≤70 mg/dL), normoglycemic (>70 and <150 mg/dL), and hyperglycemic (≥150 mg/dL) values accurately predicted by the model; 9,405 data points were analyzed. The models successfully predicted trends in glucose in the 5 test patients. Clark Error Grid Analysis indicated that 100.0% of predictions were clinically acceptable with 87.3% and 12.7% of predicted values falling within regions A and B of the error grid respectively. Overall model error (MAD%) was 9.0% with respect to actual continuous glucose modeling data. Our model successfully predicted 96.7% and 53.6% of the normo- and hyperglycemic values respectively. No hypoglycemic events occurred in these patients. Use of neural network models for real-time prediction of glucose in the surgical intensive care unit setting offers healthcare providers potentially useful information which could facilitate optimization of glycemic control, patient safety, and improved care. Similar models can be implemented across a wider scale of biomedical variables to offer real-time optimization, training, and adaptation that increase predictive accuracy and performance of therapies.

In-Hospital Management of Diabetes.

In-Hospital Management of Diabetes.

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Introduction: Sedation and analgesia are an integral part of the multimodal management of critically ill patients. Patients are often treated with continuous intravenous infusions of sedatives and analgesics. However, continuous infusions have been associated with prolonged mechanical ventilation and longer intensive care unit (ICU) stay. The use of protocols in the ICU promote evidence-based practice and may reduce inter-clinician variability. Utilization of dexmedetomidine in ICU sedation and analgesia practice may decrease time mechanically ventilated. Hypothesis: We hypothesized initiation of a sedation and analgesia protocol including the use of dexmedetomidine will decrease time to ventilator liberation, and ICU length of stay. Methods: A multidisciplinary team at an urban academic medical center created a sedation and analgesia protocol to include early use of dexmedetomidine for patients requiring sedative infusions. Data was collected in a prospective cohort design from a seventeen bed surgical ICU for a three month period pre and post implementation of the protocol. The primary outcome was number of ventilator free days. Secondary outcome measures were ICU length of stay (LOS), overall hospital LOS, and cumulative dosing of sedatives and analgesics during mechanical ventilation. Patients were excluded if they were not mechanically ventilated, not receiving continuous infusions of sedatives or analgesics, required greater than 28 days of mechanical ventilation, or were receiving continuous neuromuscular blockade. Results: One hundred and sixty six patients (83 pre implementation and 95 post implementation) were collected. The groups were well matched for age (59.1 vs 58 years old), gender (40% vs 42% female) and APACHE II scores (13.5 vs 12.9). A two-tailed t-test performed comparing days to ventilator liberation resulted in less days post implementation of the protocol (5.67 vs 4.28 days [p=0.083]) while ICU LOS (9.08 vs 8.92 days) and hospital LOS (21.1 vs 20.2 days) remained similar. Conclusions: Institution of a sedation and analgesia protocol with the early use of dexmedetomidine in the surgical ICU setting may increase ventilator free days. Larger trials are needed to further evaluate this relationship.

Integrating palliative care in the surgical and trauma intensive care unit

Although successful models for palliative care delivery and quality improvement in the intensive care unit have been described, their applicability in surgical intensive care unit settings has not been fully addressed. We undertook to define specific challenges, strategies, and solutions for integration of palliative care in the surgical intensive care unit. We searched the MEDLINE database from inception to May 2011 for all English language articles using the term "surgical palliative care" or the terms "surgical critical care," "surgical ICU," "surgeon," "trauma" or "transplant," and "palliative care" or "end-of- life care" and hand-searched our personal files for additional articles. Based on review of these articles and the experiences of our interdisciplinary expert Advisory Board, we prepared this report. We critically reviewed the existing literature on delivery of palliative care in the surgical intensive care unit setting focusing on challenges, strategies, models, and interventions to promote effective integration of palliative care for patients receiving surgical critical care and their families. Characteristics of patients with surgical disease and practices, attitudes, and interactions of different disciplines on the surgical critical care team present distinctive issues for intensive care unit palliative care integration and improvement. Physicians, nurses, and other team members in surgery, critical care and palliative care (if available) should be engaged collaboratively to identify challenges and develop strategies. "Consultative," "integrative," and combined models can be used to improve intensive care unit palliative care, although optimal use of trigger criteria for palliative care consultation has not yet been demonstrated. Important components of an improvement effort include attention to efficient work systems and practical tools and to attitudinal factors and "culture" in the unit and institution. Approaches that emphasize delivery of palliative care together with surgical critical care hold promise to better integrate palliative care into the surgical intensive care unit.

Novel Therapeutic Targets for Sepsis: Regulation of Exaggerated Inflammatory Responses

Sepsis is a devastating and complex syndrome and continues to be a major cause of morbidity and mortality among critically ill patients at the surgical intensive care unit setting in the United States. The occurrence of sepsis and septic shock has increased significantly over the past two decades. Despite of highly dedicated basic research and numerous clinical trials, remarkable progress has not been made in the development of novel and effective therapeutics. The sepsis-induced physiologic derangements are due largely to the host responses to the invading microorganism in contrast to the direct effects of the microorganism itself. Sepsis, the systemic inflammatory response to infection, is marked by dysregulated production of pro-inflammatory cytokines. Although pro-inflammatory cytokine production is normally indispensable to protect against pathogens and promote tissue repair, the dysregulated and prolonged production of these cytokines can trigger a systemic inflammatory cascade mediated by chemokines, vasoactive amines, the complement and coagulation system, and reactive oxygen species (ROS), amongst others. These mediators collectively lead to multiple organ failure, and ultimately to death. In this regard, the role of inflammation in the pathophysiology of sepsis, although still incompletely understood, is clearly critical. Recent findings resulting from vigorous investigations have contributed to delineate various novel directions of sepsis therapeutics. Among these, this review article is focused on new promising mechanisms and concepts that could have a key role in anti-inflammatory strategies against sepsis, including 1) "inflammasome": a multiprotein complex that activates caspase-1; 2) "the cholinergic anti-inflammatory pathway": the efferent arm of the vagus nerve-mediated, brain-to-immune reflex; 3) "stem cells": unspecialized and undifferentiated precursor cells with the capacity for self-renewal and potential to change into cells of multiple lineages; 4) "milk fat globule-EGF factor VIII (MFG-E8)": a bridging molecule between apoptotic cells and phagocytes, which promotes phagocytosis of apoptotic cells.

Prospective Survey of (1→3)-β- d -Glucan and Its Relationship to Invasive Candidiasis in the Surgical Intensive Care Unit Setting

Non-culture-based diagnostic strategies are needed for diagnosing invasive candidiasis (IC). We evaluated serial serum (1→3)-β-d-glucan (BG) levels in patients in the surgical trauma intensive care unit (SICU) patients with clinical evidence of IC. Serum samples from patients admitted to the SICU for a minimum of 3 days were collected twice weekly and analyzed for BG by using a Fungitell kit with a positive cutoff of ≥ 80 pg/ml. Diagnosis of IC was done using a set of predefined and validated clinical practice-based criteria. A total of 57 patients consented to participate and were enrolled. The median ICU stay was 16 days (range, 3 to 51). A total of 14 of 57 (25%) false positives were observed in the first sample (ICU day 3) and, overall, 73% of the day 3 samples had higher BG levels than subsequent samples. On the date of clinical diagnosis of IC, the sensitivity of a positive BG for identifying invasive candidiasis was 87%, with a 73% specificity. In patients with evidence of IC, the median BG value was significantly higher than those without evidence of IC (171 versus 48 pg/ml, P = 0.02), respectively. In the three patients with proven IC, BG was detected 4 to 8 days prior to diagnosis. BG serum detection may be a useful tool to aid in the early diagnosis of IC in SICU patients, particularly after day 3 and in patients with at least two positive samples drawn several days apart. Elevated BG levels within the first 3 days need to be further characterized.

Milk Fat Globule-EGF Factor VIII in Sepsis and Ischemia-Reperfusion Injury

Sepsis and ischemia-reperfusion (I/R) injury are among the leading causes of death in critically ill patients at the surgical intensive care unit setting. Both conditions are marked by the excessive inflammatory response which leads to a lethal disease complex such as acute lung injury, systemic inflammatory response syndrome and multiple organ dysfunction syndrome. Despite the advances in the understanding of the pathophysiology of those conditions, very little progress has been made toward therapeutic interventions. One of the key aspects of these conditions is the accumulation of apoptotic cells that have the potential to release toxic and proinflammatory contents due to secondary necrosis without appropriate clearance by phagocytes. Along with the prevention of apoptosis, that is reported to be beneficial in sepsis and I/R injury, thwarting the development of secondary necrosis through the active removal of apoptotic cells via phagocytosis may offer a novel therapy. Milk fat globule-EGF factor VIII (MFG-E8), which is mainly produced by macrophages and dendritic cells, is an opsonin for apoptotic cells and acts as a bridging protein between apoptotic cells and phagocytes. Recently, we have shown that MFG-E8 expression is decreased in experimental sepsis and I/R injury models. Exogenous administration of MFG-E8 attenuated the inflammatory response as well as tissue injury and mortality through the promotion of phagocytosis of apoptotic cells. In this review, we describe novel information available about the involvement of MFG-E8 in the pathophysiology of sepsis and I/R injury, and the therapeutic potential of exogenous MFG-E8 treatment for those conditions.

Delirium in the Intensive Care Unit: Medications as Risk Factors

Delirium in the Intensive Care Unit: Medications as Risk Factors

Quantity and Quality of Sleep in the Surgical Intensive Care Unit: Are Our Patients Sleeping?

The lack of adequate sleep during intensive care unit (ICU) admission is a frequently overlooked complication. Disrupted sleep is associated with immune system dysfunction, impaired resistance to infection, as well as alterations in nitrogen balance and wound healing. The effects of surgical ICU admission on patients' sleep quality and architecture remain poorly defined. The purpose of this study was to describe the quantity and quality of sleep as well as sleep architecture, as defined by polysomnography (PSG), in patients cared for in the surgical ICU. A prospective observational cohort study was performed at our urban Level I trauma center. A convenience sample of surgical or trauma ICU patients underwent continuous PSG for up to 24 hours to evaluate sleep patterns. A certified sleep technician performed, monitored, and scored all PSG recordings. A single neurologist trained in PSG interpretation reviewed all PSG recordings. chi goodness-of-fit analysis was performed to detect differences in the proportion of time spent in stages 1 and 2 (superficial stages), stages 3 and 4 (deep stages), or rapid eye movement (REM) sleep between study patients and healthy historical controls. All PSG recordings were performed greater than 24 hours after the administration of a general anesthetic. Patients with traumatic brain injury were excluded. Sixteen patients were selected to undergo PSG recordings. Median age was 37.5 years (range, 20-83), 81.3% were male patients, 62.5% were injured, and 31.3% were mechanically ventilated. Total PSG recording time was 315 hours (mean, 19.7 hours per patient), total sleep time captured by PSG was 132 hours (mean, 8.28 hours per patient), and there were 6.2 awakenings per hour of sleep measured. ICU patients had an increase in the proportion of time spent in the superficial stages of sleep, and a decrease in the proportion of time spent in the deeper stages of sleep as well as a decrease in REM sleep compared with healthy controls (p < 0.001). Patients do achieve measurable sleep while cared for in a surgical ICU setting. However, sleep is fragmented and the quality of sleep is markedly abnormal with significant reductions in stages 3 and 4 and REM, the deeper restorative stages of sleep. Further studies on the effects of a strategy to promote sleep during ICU care are warranted.

Molecular epidemiology of gastric colonization by Enterococcus faecalis in a surgical intensive care unit

We applied restriction endonuclease analysis of genomic DNA using pulsed field gel electrophoresis (PFGE) to study gastric colonization with Enterococcus faecalis among patients hospitalized in the surgical intensive care unit (SICU). Isolates were obtained by culturing prospectively the gastric contents of 140 patients in the SICU. In addition, cultures of respiratory specimens were obtained daily and cultures of blood, normally sterile body fluids, wounds, and urine were obtained when indicated clinically. A total of 177 isolates were obtained from 45 patients. Concentrations of E. faecalis in gastric fluid ranged from 1 x 10(2) colony forming units (CFU)/ml to greater than 5 x 10(7) CFU/ml (mean 8.0 x 10(6) CFU/ml). Overall, 33 different DNA types were identified by PEGE. In examining strain variation among isolates obtained from multiple anatomic sites over time, we found that the same DNA type was recovered from gastric aspirates, sputum, and wounds in a given patient and that these strains were carried over time. In general, given individuals were colonized with their own unique DNA type; however, one DNA type (type C) was shared by 11 different patients, and seven DNA types were shared by two individuals each. These results demonstrate the potential importance of gastric colonization as a reservoir for nosocomial strains of E. faecalis in an SICU setting.

Fuzzy control of mean arterial pressure in postsurgical patients with sodium nitroprusside infusion.

We developed a fuzzy control system to provide closed-loop control of mean arterial pressure (MAP) in postsurgical patients in a cardiac surgical intensive care unit setting by regulating sodium nitroprusside (SNP) infusion. The fuzzy controller, originally expert-system-based, was analytically converted to ten nonfuzzy control algorithms, which reduced execution time dramatically. The core of the control algorithms was a nonlinear proportional-integral (PI) controller whose proportional gain and integral gain adjusted continuously according to error and rate change of error of the process output. The gains became larger when process output was far from desired setpoint and smaller when process output was close to desired setpoint, resulting in more dynamic and stable control performance than the regular PI controller, especially when a linear process with time-delay or a nonlinear process was involved. The control algorithms, encoded in C programming language, were implemented to control MAP in patients. Preliminary clinical results showed that the average percentage of time in which MAP stayed between 90% and 110% of the MAP setpoint was 89.31%, with a standard deviation of 4.96%. These were calculated based on 12 patient trials, with total trial time of 95 and 13 min.