Practical sources of error in measuring pulmonary artery occlusion pressure: a study in participants of a special intensivist training program of The Scandinavian Society of Anaesthesiology and Intensive Care Medicine (SSAI)

BACKGROUND: Physiological data obtained with the pulmonary artery catheter (PAC) are susceptible to errors in measurement and interpretation. Little attention has been paid to the relevance of errors in hemodynamic measurements performed in the intensive care unit (ICU). The aim of this study was to assess the errors related to the technical aspects (zeroing and reference level) and actual measurement (curve interpretation) of the pulmonary artery occlusion pressure (PAOP). METHODS: Forty-seven participants in a special ICU training program and 22 ICU nurses were tested without pre-announcement. All participants had previously been exposed to the clinical use of the method. The first task was to set up a pressure measurement system for PAC (zeroing and reference level) and the second to measure the PAOP. RESULTS: The median difference from the reference mid-axillary zero level was - 3 cm (-8 to + 9 cm) for physicians and -1 cm (-5 to + 1 cm) for nurses. The median difference from the reference PAOP was 0 mmHg (-3 to 5 mmHg) for physicians and 1 mmHg (-1 to 15 mmHg) for nurses. When PAOP values were adjusted for the differences from the reference transducer level, the median differences from the reference PAOP values were 2 mmHg (-6 to 9 mmHg) for physicians and 2 mmHg (-6 to 16 mmHg) for nurses. CONCLUSIONS: Measurement of the PAOP is susceptible to substantial error as a result of practical mistakes. Comparison of results between ICUs or practitioners is therefore not possible.

[Neuromonitoring and neuroprotection in cardiac anaesthesia. Nationwide survey conducted by the Cardiac Anaesthesia Working Group of the German Society of Anaesthesiology and Intensive Care Medicine]

OBJECTIVE: The primary objective of this nationwide survey carried out in department of cardiac anesthesia in Germany was to identify current practice with regard to neuromonitoring und neuroprotection. METHODOLOGY: The data are based on a questionnaire sent out to all departments of cardiac anesthesia in Germany between October 2007 und January 2008. The anonymized questionnaire contained 26 questions about the practice of preoperative evaluation of cerebral vessels, intra-operative use of neuromonitoring, the nature und application of cerebral protective measures, perfusion management during cardiopulmonary bypass, postoperative evaluation of neurological status, and training in the field of cerebral monitoring. RESULTS: Of the 80 mailed questionnaires 55% were returned and 90% of department evaluated cerebral vessels preoperatively with duplex ultrasound. The methods used for intra-operative neuromonitoring are electroencephalography (EEG, 60%) for type A dissections (38.1%), for elective surgery on the thoracic and thoraco-abdominal aorta (34.1% and 31.6%, respectively) and in carotid surgery (43.2%) near infrared spectroscopy (40%), evoked potentials (30%) and transcranial Doppler sonography (17.5%), with some centers using combined methods. In most departments the central nervous system is not subjected to monitoring during bypass surgery, heart valve surgery, or minimally invasive surgery. Cerebral protective measures used comprise patient cooling on cardio-pulmonary bypass (CPB 100%), extracorporeal cooling of the head (65%) and the administration of corticosteroids (58%), barbiturates (50%) and antiepileptic drugs (10%). Neuroprotective anesthesia consists of administering inhalation anesthetics (32.5%; sevoflurane 76.5%) and intravenous anesthesia (20%; propofol and barbiturates each accounting for 46.2%). Of the departments 72.5% cool patients as a standard procedure for surgery involving cardiovascular arrest and 37.5% during all surgery using CPB. In 84.6% of department CPB flow equals calculated cardiac output (CO) under normothermia, while the desired mean arterial pressure (MAP) varies between 60 and 70 mmHg (43.9%) and between 50 and 60 mmHg (41.5%), respectively. At body temperatures less than 18 degrees C CPB flow is reduced below the calculated CO (70%) while 27% of departments use normothermic flow rates. The preferred MAP under hypothermia is between 50 and 60 mmHg (59%). The results of intra-operative neuromonitoring are documented on the anesthesia record (77%). In 42.5% of the departments postoperative neurological function is estimated by the anesthesiologist. Continuing education sessions pertaining to neuromonitoring are organized on a regular basis in 32.5% of the departments and in 37.5% individual physicians are responsible for their own neuromonitoring education. CONCLUSION: The present survey data indicate that neuromonitoring and neuroprotective therapy during CPB is not standardized in cardiac anesthesiology departments in Germany. The systemic use of available methods to implement multimodal neuromonitoring would be desirable.

Prospective population-based study of RSV-related intermediate care and intensive care unit admissions in Switzerland over a 4-year period (2001-2005)

OBJECTIVES: Respiratory syncytial virus (RSV) infections are a leading cause of hospital admissions in small children. A substantial proportion of these patients require medical and nursing care, which can only be provided in intermediate (IMC) or intensive care units (ICU). This article reports on all children aged < 3 years who required admission to IMC and/or ICU between October 1, 2001 and September 30, 2005 in Switzerland. PATIENTS AND METHODS: We prospectively collected data on all children aged < 3 years who were admitted to an IMC or ICU for an RSV-related illness. Using a detailed questionnaire, we collected information on risk factors, therapy requirements, length of stay in the IMC/ICU and hospital, and outcome. RESULTS: Of the 577 cases reported during the study period, 90 were excluded because the patients did not fulfill the inclusion criteria; data were incomplete in another 25 cases (5%). Therefore, a total of 462 verified cases were eligible for analysis. At the time of hospital admission, only 31 patients (11%) were older than 12 months. Since RSV infection was not the main reason for IMC/ICU admission in 52% of these patients, we chose to exclude this subgroup from further analyses. Among the 431 infants aged < 12 months, the majority (77%) were former near term or full term (NT/FT) infants with a gestational age > or = 35 weeks without additional risk factors who were hospitalized at a median age of 1.5 months. Gestational age (GA) < 32 weeks, moderate to severe bronchopulmonary dysplasia (BPD), and congenital heart disease (CHD) were all associated with a significant risk increase for IMC/ICU admission (relative risk 14, 56, and 10, for GA < or = 32 weeks, BPD, and CHD, respectively). Compared with NT/FT infants, high-risk infants were hospitalized at an older age (except for infants with CHD), required more invasive and longer respiratory support, and had longer stays in the IMC/ICU and hospital. CONCLUSIONS: In Switzerland, RSV infections lead to the IMC/ICU admission of approximately 1%-2% of each annual birth cohort. Although prematurity, BPD, and CHD are significant risk factors, non-pharmacological preventive strategies should not be restricted to these high-risk patients but also target young NT/FT infants since they constitute 77% of infants requiring IMC/ICU admission.

Monitoring of emergency and intensive care patients: simple diagnostic aids

This article describes in short sections the use and interpretation of indirect blood pressure measurements, central venous pressure, body temperature, pulse oximetry, end tidal CO2 measurements, pulse and heart rate, urine production and emergency laboratory values. Most of these parameters are directly or indirectly linked to the perfusion of the patient. Optimizing these values are one of the most important goals in emergency and critical care medicine.

Auditory event-related potentials, bispectral index, and entropy for the discrimination of different levels of sedation in intensive care unit patients

BACKGROUND: Sedation protocols, including the use of sedation scales and regular sedation stops, help to reduce the length of mechanical ventilation and intensive care unit stay. Because clinical assessment of depth of sedation is labor-intensive, performed only intermittently, and interferes with sedation and sleep, processed electrophysiological signals from the brain have gained interest as surrogates. We hypothesized that auditory event-related potentials (ERPs), Bispectral Index (BIS), and Entropy can discriminate among clinically relevant sedation levels. METHODS: We studied 10 patients after elective thoracic or abdominal surgery with general anesthesia. Electroencephalogram, BIS, state entropy (SE), response entropy (RE), and ERPs were recorded immediately after surgery in the intensive care unit at Richmond Agitation-Sedation Scale (RASS) scores of -5 (very deep sedation), -4 (deep sedation), -3 to -1 (moderate sedation), and 0 (awake) during decreasing target-controlled sedation with propofol and remifentanil. Reference measurements for baseline levels were performed before or several days after the operation. RESULTS: At baseline, RASS -5, RASS -4, RASS -3 to -1, and RASS 0, BIS was 94 [4] (median, IQR), 47 [15], 68 [9], 75 [10], and 88 [6]; SE was 87 [3], 46 [10], 60 [22], 74 [21], and 87 [5]; and RE was 97 [4], 48 [9], 71 [25], 81 [18], and 96 [3], respectively (all P < 0.05, Friedman Test). Both BIS and Entropy had high variabilities. When ERP N100 amplitudes were considered alone, ERPs did not differ significantly among sedation levels. Nevertheless, discriminant ERP analysis including two parameters of principal component analysis revealed a prediction probability PK value of 0.89 for differentiating deep sedation, moderate sedation, and awake state. The corresponding PK for RE, SE, and BIS was 0.88, 0.89, and 0.85, respectively. CONCLUSIONS: Neither ERPs nor BIS or Entropy can replace clinical sedation assessment with standard scoring systems. Discrimination among very deep, deep to moderate, and no sedation after general anesthesia can be provided by ERPs and processed electroencephalograms, with similar P(K)s. The high inter- and intraindividual variability of Entropy and BIS precludes defining a target range of values to predict the sedation level in critically ill patients using these parameters. The variability of ERPs is unknown.

Association between trends in clinical variables and outcome in intensive care patients with faecal peritonitis: analysis of the GenOSept cohort.

INTRODUCTION Patients admitted to intensive care following surgery for faecal peritonitis present particular challenges in terms of clinical management and risk assessment. Collaborating surgical and intensive care teams need shared perspectives on prognosis. We aimed to determine the relationship between dynamic assessment of trends in selected variables and outcomes. METHODS We analysed trends in physiological and laboratory variables during the first week of intensive care unit (ICU) stay in 977 patients at 102 centres across 16 European countries. The primary outcome was 6-month mortality. Secondary endpoints were ICU, hospital and 28-day mortality. For each trend, Cox proportional hazards (PH) regression analyses, adjusted for age and sex, were performed for each endpoint. RESULTS Trends over the first 7 days of the ICU stay independently associated with 6-month mortality were worsening thrombocytopaenia (mortality: hazard ratio (HR) = 1.02; 95% confidence interval (CI), 1.01 to 1.03; P <0.001) and renal function (total daily urine output: HR =1.02; 95% CI, 1.01 to 1.03; P <0.001; Sequential Organ Failure Assessment (SOFA) renal subscore: HR = 0.87; 95% CI, 0.75 to 0.99; P = 0.047), maximum bilirubin level (HR = 0.99; 95% CI, 0.99 to 0.99; P = 0.02) and Glasgow Coma Scale (GCS) SOFA subscore (HR = 0.81; 95% CI, 0.68 to 0.98; P = 0.028). Changes in renal function (total daily urine output and renal component of the SOFA score), GCS component of the SOFA score, total SOFA score and worsening thrombocytopaenia were also independently associated with secondary outcomes (ICU, hospital and 28-day mortality). We detected the same pattern when we analysed trends on days 2, 3 and 5. Dynamic trends in all other measured laboratory and physiological variables, and in radiological findings, changes inrespiratory support, renal replacement therapy and inotrope and/or vasopressor requirements failed to be retained as independently associated with outcome in multivariate analysis. CONCLUSIONS Only deterioration in renal function, thrombocytopaenia and SOFA score over the first 2, 3, 5 and 7 days of the ICU stay were consistently associated with mortality at all endpoints. These findings may help to inform clinical decision making in patients with this common cause of critical illness.

Controversies in the use of hydroxyethyl starch solutions in small animal emergency and critical care

OBJECTIVES: To (1) review the development and medical applications of hydroxyethyl starch (HES) solutions with particular emphasis on its physiochemical properties; (2) critically appraise the available evidence in human and veterinary medicine, and (3) evaluate the potential risks and benefits associated with their use in critically ill small animals. DATA SOURCES: Human and veterinary original research articles, scientific reviews, and textbook sources from 1950 to the present. HUMAN DATA SYNTHESIS: HES solutions have been used extensively in people for over 30 years and ever since its introduction there has been a great deal of debate over its safety and efficacy. Recently, results of seminal trials and meta-analyses showing increased risks related to kidney dysfunction and mortality in septic and critically ill patients, have led to the restriction of HES use in these patient populations by European regulatory authorities. Although the initial ban on the use of HES in Europe has been eased, proof regarding the benefits and safety profile of HES in trauma and surgical patient populations has been requested by these same European regulatory authorities. VETERINARY DATA SYNTHESIS: The veterinary literature is limited mostly to experimental studies and clinical investigations with small populations of patients with short-term end points and there is insufficient evidence to generate recommendations. CONCLUSIONS: Currently, there are no consensus recommendations regarding the use of HES in veterinary medicine. Veterinarians and institutions affected by the HES restrictions have had to critically reassess the risks and benefits related to HES usage based on the available information and sometimes adapt their procedures and policies based on their reassessment. Meanwhile, large, prospective, randomized veterinary studies evaluating HES use are needed to achieve relevant levels of evidence to enable formulation of specific veterinary guidelines.

The role of Acinetobacter baumannii as a nosocomial pathogen for dogs and cats in an intensive care unit.

Acinetobacter baumannii is a nosocomial pathogen associated with high morbidity and mortality in humans. Whereas infections with strains of Acinetobacter species have been reported in various situations, the importance of A baumannii as a nosocomial pathogen in veterinary hospitals has not been studied so far. In this retrospective case series, we describe 17 dogs and 2 cats from which A baumannii had been isolated during a 2 1/2-year period. In 7 dogs, A baumannii induced systemic signs of illness, whereas 12 animals showed signs of local infection. In all animals with systemic infection, and in 2 with localized infection, A baumannii contributed to the death of the animal or contributed to euthanasia; the remaining 8 dogs and both cats recovered. Molecular typing of the isolates with restriction polymorphisms of ribosomal DNA provided evidence of nosocomial spread of this pathogen and for the presence of several strains of A baumannii in the hospital environment.

Prevention, diagnosis, therapy and follow-up care of sepsis: 1st revision of S-2k guidelines of the German Sepsis Society (Deutsche Sepsis-Gesellschaft e.V. (DSG)) and the German Interdisciplinary Association of Intensive Care and Emergency Medicine (Deutsche Interdisziplinäre Vereinigung für Intensiv- und Notfallmedizin (DIVI))

Practice guidelines are systematically developed statements and recommendations that assist the physicians and patients in making decisions about appropriate health care measures for specific clinical circumstances taking into account specific national health care structures. The 1(st) revision of the S-2k guideline of the German Sepsis Society in collaboration with 17 German medical scientific societies and one self-help group provides state-of-the-art information (results of controlled clinical trials and expert knowledge) on the effective and appropriate medical care (prevention, diagnosis, therapy and follow-up care) of critically ill patients with severe sepsis or septic shock. The guideline had been developed according to the "German Instrument for Methodological Guideline Appraisal" of the Association of the Scientific Medical Societies (AWMF). In view of the inevitable advancements in scientific knowledge and technical expertise, revisions, updates and amendments must be periodically initiated. The guideline recommendations may not be applied under all circumstances. It rests with the clinician to decide whether a certain recommendation should be adopted or not, taking into consideration the unique set of clinical facts presented in connection with each individual patient as well as the available resources.

Current approach to the haemodynamic management of septic shock patients in European intensive care units: a cross-sectional, self-reported questionnaire-based survey

The aim of this survey was to investigate clinicians' current approach to the haemodynamic management and resuscitation endpoints in septic shock.

Gastrointestinal function in intensive care patients: terminology, definitions and management. Recommendations of the ESICM Working Group on Abdominal Problems

Acute gastrointestinal (GI) dysfunction and failure have been increasingly recognized in critically ill patients. The variety of definitions proposed in the past has led to confusion and difficulty in comparing one study to another. An international working group convened to standardize the definitions for acute GI failure and GI symptoms and to review the therapeutic options.

Point-of-care prothrombin time testing in paediatric intensive care: an observational study of the ease of use of two devices

Two major difficulties arise when taking blood samples in children: the challenge of venous access and the comparatively large amount of blood required.