Arterial blood pressure monitoring in overweight critically ill patients: invasive or noninvasive?

Introduction  

Blood pressure measurements frequently guide management in critical care. Direct readings, commonly from a major artery, are considered to be the gold standard. Because arterial cannulation is associated with risks, alternative noninvasive blood pressure (NIBP) measurements are routinely used. However, the accuracy of NIBP determinations in overweight patients in the outpatient setting is variable, and little is known about critically ill patients. This prospective, observational study was performed to compare direct intra-arterial blood pressure (IABP) with NIBP measurements obtained using auscultatory and oscillometric methods in overweight patients admitted to our medical intensive care unit.     

Evidence of altered cortisol metabolism in critically ill patients: a prospective study

Context Changes in cortisol metabolism due to altered activity of the enzyme 11β-hydroxysteroid dehydrogenase (11β-HSD) have been implicated in the pathogenesis of hypertension, obesity and the metabolic syndrome. No published data exist on the activity of this enzyme in critical illness. Objective To investigate cortisol metabolism in critically ill patients utilising plasma cortisol: cortisone ratio as an index of 11β-HSD activity. Setting Tertiary level intensive care unit. Patients Three cohorts of critically ill patients: sepsis (n = 13); multitrauma (n = 20); and burns (n = 19). Main outcome measures Serial plasma cortisol: cortisone ratios. Measurements and main results Plasma total cortisol cortisone ratios were determined serially after admission to the intensive care unit. As compared with controls, the plasma cortisol:cortisone ratio was significantly elevated in the sepsis and trauma cohorts on day 1 (22 ± 9, p = 0.01, and 23 ± 19, p = 0.0003, respectively) and remained elevated over the study period. Such a relationship was not demonstrable in burns. The ratio was significantly correlated with APACHE II (r = 0.77, p = 0.0008) and Simplified Acute Physiology Score (r = 0.7, p = 0.003) only on day 7 and only in the burns cohort. There were no significant correlations observed between total plasma cortisol or cortisone and sickness severity in the sepsis and trauma cohorts. Conclusions In critically ill patients, there is evidence of altered cortisol metabolism due to an increase in 11β-HSD activity as demonstrated by an elevation of plasma cortisol: cortisone ratios. Further studies with larger sample sizes specifically designed to examine altered tissue 11β-HSD activity and its clinical significance and correlation with outcome are warranted.     

Scoring systems in critically ill: Which one to use in cancer patients?

BACKGROUNDScoring systems have not been evaluated in oncology patients. We aimed to assess the performance of Acute Physiology and Chronic Health Evaluation (APACHE) II, APACHE III, APACHE IV, Simplified Acute Physiology Score (SAPS) II, SAPS III, Mortality Probability Model (MPM) II₀ and Sequential Organ Failure Assessment (SOFA) score in critically ill oncology patients.AIMTo compare the efficacy of seven commonly employed scoring systems to predict outcomes of critically ill cancer patients.METHODSWe conducted a retrospective analysis of 400 consecutive cancer patients admitted in the medical intensive care unit over a two-year period. Primary outcome was hospital mortality and the secondary outcome measure was comparison of various scoring systems in predicting hospital mortality. RESULTSIn our study, the overall intensive care unit and hospital mortality was 43.5% and 57.8%, respectively. All of the seven tested scores underestimated mortality. The mortality as predicted by MPM II₀ predicted death rate (PDR) was nearest to the actual mortality followed by that predicted by APACHE II, with a standardized mortality rate (SMR) of 1.305 and 1.547, respectively. The best calibration was shown by the APACHE III score (χ² = 4.704, P = 0.788). On the other hand, SOFA score (χ² = 15.966, P = 0.025) had the worst calibration, although the difference was not statistically significant. All of the seven scores had acceptable discrimination with good efficacy however, SAPS III PDR and MPM II₀ PDR (AUROC = 0.762), had a better performance as compared to others. The correlation between the different scoring systems was significant (P < 0.001).CONCLUSIONAll the severity scores were tested under-predicted mortality in the present study. As the difference in efficacy and performance was not statistically significant, the choice of scoring system used may depend on the ease of use and local preferences.     

Duration of adrenal inhibition following a single dose of etomidate in critically ill patients

Objective To determine the incidence and duration of adrenal inhibition induced by a single dose of etomidate in critically ill patients. Design Prospective, observational cohort study. Setting Three intensive care units in a university hospital. Patients Forty critically ill patients without sepsis who received a single dose of etomidate for facilitating endotracheal intubation. Measurements and main results Serial serum cortisol and 11β-deoxycortisol samples were taken at baseline and 60 min after corticotropin stimulation test (250 μg 1–24 ACTH) at 12, 24, 48, and 72 h after etomidate administration. Etomidate-related adrenal inhibition was defined by the combination of a rise in cortisol less than 250 nmol/l (9 μg/dl) after ACTH stimulation and an excessive accumulation of serum 11β-deoxycortisol concentrations at baseline. At 12 h after etomidate administration, 32/40 (80%) patients fulfilled the diagnosis criteria for etomidate-related adrenal insufficiency. This incidence was significantly lower at 48 h (9%) and 72 h (7%). The cortisol to 11β-deoxycortisol ratio (F/S ratio), reflecting the intensity of the 11β-hydroxylase enzyme blockade, improved significantly over time. Conclusions A single bolus infusion of etomidate resulted in wide adrenal inhibition in critically ill patients. However, this alteration was reversible by 48 h following the drug administration. The empirical use of steroid supplementation for 48 h following a single dose of etomidate in ICU patients without septic shock should thus be considered. Concomitant serum cortisol and 11β-deoxycortisol dosages are needed to provide evidence for adrenal insufficiency induced by etomidate in critically ill patients. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. Financial support: All of the authors have disclosed that they have no financial relationship with or interest in any commercial companies.     

A comparison of early gastric and post-pyloric feeding in critically ill patients: a meta-analysis

Objective To investigate the potential beneficial and adverse effects of early post-pyloric feeding compared with gastric feeding in critically ill adult patients with no evidence of impaired gastric emptying.Design Randomised controlled studies comparing gastric and post-pyloric feeding in critically ill adult patients from Cochrane Controlled Trial Register (2005 issue 3), EMBASE and MEDLINE databases (1966 to 1 October 2005) without any language restriction were included. Two reviewers reviewed the quality of the studies and performed data extraction independently.Measurements and results Eleven randomised controlled studies with a total of 637 critically ill adult patients were considered. The mortality (relative risk [RR] 1.01, 95% CI 0.76–1.36, p = 0.93; I ² = 0%) and risk of aspiration or pneumonia (RR 1.28, 95% CI 0.91–1.80, p = 0.15; I ² = 0%) were not significantly different between patients treated with gastric or post-pyloric feeding. The effect of post-pyloric feeding on the risk of pneumonia or aspiration was similar when studies were stratified intothose with and those without the use of concurrent gastric decompression (RR ratio 0.95, 95% CI 0.48–1.91, p = 0.89). The risk of diarrhoea and the length of intensive care unit stay (weighted mean difference in days –1.46, 95% CI –3.74 to 0.82,p = 0.21; I ² = 24.6%) were not statistically different. The gastric feeding group had a much lower risk of experiencing feeding tube placement difficulties or blockage (0 vs 9.6%, RR 0.13, 95% CI 0.04–0.44, p = 0.001; I ² = 0%).Conclusions Early use of post-pyloric feeding instead of gastric feeding in critically ill adult patients with no evidence of impaired gastric emptying was not associated with significant clinical benefits.This study was solely funded by the Department of Intensive Care, Royal Perth Hospital. No financial support was received for this study from pharmaceutical companies or other private companies in the form of grants and awards.     

Prophylactic protective ventilation: lower tidal volumes for all critically ill patients?

High tidal volumes have historically been recommended for mechanically ventilated patients during general anesthesia. High tidal volumes have been shown to increase morbidity and mortality in patients suffering from acute respiratory distress syndrome (ARDS). Barriers exist in implementing a tidal volume reduction strategy related to the inherent difficulty in changing one's practice patterns, to the current need to individualize low tidal volume settings only for a specific subgroup of mechanically ventilated patients (i.e., ARDS patients), the difficulty in determining the predicated body weight (requiring the patient's height and a complex formula). Consequently, a protective ventilation strategy is often under-utilized as a therapeutic option, even in ARDS. Recent data supports the generalization of this strategy prophylactically to almost all mechanically ventilated patients beginning immediately following intubation. Using tools to rapidly and reliably determine the predicted body weight (PBW), as well as the use of automated modes of ventilation are some of the potential solutions to facilitate the practice of protective ventilation and to finally ventilate our patients?? lungs in a more gentle fashion to help prevent ARDS.     

Hyperglycaemia in critically ill patients: marker or mediator of mortality?

Acute hyperglycaemia has been associated with complications, prolonged intensive care unit and hospital stay, and increased mortality. We made an inventory of the prevalence and prognostic value of hyperglycaemia, and of the effects of glucose control in different groups of critically ill patients. The prevalence of hyperglycaemia in critically ill patients, using stringent criteria, approaches 100%. An unambiguous negative correlation between hyperglycaemia and mortality has been described in various groups of critically ill patients. Although the available evidence remains inconsistent, there appears to be a favourable effect of glucose regulation. This effect on morbidity and mortality depends on patient characteristics. To be able to compare results of future studies involving glucose regulation, better definitions of hyperglycaemia (and consequently of normoglycaemia) and patient populations are needed.     

Statins: a role in infected critically ill patients?

Terblanche and colleagues add to the ongoing controversy over the role, if any, for statins in patients with sepsis. The authors note that statins fail to prevent progression to organ dysfunction in critically ill patients. However, like most publications, the study is retrospective and stimulates the controversy but fails to resolve it. The time has come for robust randomized controlled clinical trials.     

Fish oil supplementation in the parenteral nutrition of critically ill medical patients: a randomised controlled trial

OBJECTIVE: To test whether supplementation of parenteral nutrition with fish oil - aimed at increasing the n-3:n-6 ratio of polyunsaturated fatty acids (PUFA) to 1:2 - affects systemic inflammation and clinical outcome compared to standard parenteral nutrition with an n-3/n-6 ratio of 1:7 in medical intensive care unit (ICU) patients. DESIGN: Single-centre, placebo-controlled, double-blind, randomised clinical trial. SETTING: Twelve-bed medical ICU of a university hospital. PATIENTS: A total of 166 consecutive patients anticipated to need parenteral nutrition for more than 6 days. Patients were stratified for the presence of systemic inflammatory response syndrome (SIRS) at baseline (115 SIRS, 51 non-SIRS). INTERVENTION: Patients were randomly assigned to receive either a 1:1-mixture of medium-chain triglycerides (MCT) and long-chain triglycerides (LCT) with an n-3/n-6 PUFA ratio of 1:7, or the same MCT/LCT emulsion supplemented with fish oil (resulting in an n-3/n-6 ratio of 1:2). MEASUREMENTS AND RESULTS: Primary endpoints were changes in interleukin 6 (IL-6) and monocyte HLA-DR expression relative to baseline. Secondary endpoints were incidence of nosocomial infections, duration of mechanical ventilation, length of ICU stay, and 28-day mortality. Bleeding complications were recorded as a possible side effect of fish oil. Between standard and intervention groups, overall as well as stratified for SIRS or non-SIRS, no significant difference was detected in any of the endpoints or frequency and severity of bleeding events. CONCLUSIONS: In unselected critically ill medical patients, fish oil supplementation that increased the n-3/n-6 PUFA ratio to 1:2 did not affect inflammation or clinical outcome, compared to parenteral lipid nutrition with an MCT/LCT emulsion.     

Leptin in sepsis: a well-suited biomarker in critically ill patients?

The value of monitoring serum leptin in critically ill patients is important for early diagnosis and differentiation between sepsis and non-infectious systemic inflammatory response syndrome (SIRS). The early diagnosis of sepsis, the identification of its origin, and an adequate therapeutic management are crucial to overcome sepsis-associated mortality. Cytokine levels are an obvious choice as sepsis markers, since cytokines are key mediators of the inflammatory response to sepsis. Leptin, a hormone mainly generated by adipocytes, acts centrally in the hypothalamus to regulate body weight and energy expenditure. There is, however, strong evidence that leptin is also involved in cell-mediated immunity and cytokine crosstalk. The finding that a serum leptin threshold of 38 μg/l can distinguish between sepsis and non-infectious SIRS (sensitivity 91.2%, specificity 85%) is the major finding in the article by Yousef and colleagues (in this issue). Much remains to be learned about the precise mechanisms by which leptin signaling participates in sepsis and non-infectious SIRS. This knowledge will potentially contribute to new therapeutic approaches.     

Antibiotics in critically ill patients: a systematic review of the pharmacokinetics of β-lactams

Introduction  

Several reports have shown marked heterogeneity of antibiotic pharmacokinetics (PK) in patients admitted to ICUs, which might potentially affect outcomes. Therefore, the pharmacodynamic (PD) parameter of the efficacy of β-lactam antibiotics, that is, the time that its concentration is above the bacteria minimal inhibitory concentration (T > MIC), cannot be safely extrapolated from data derived from the PK of healthy volunteers.     

Association of prophylactic synbiotics with reduction in diarrhea and pneumonia in mechanically ventilated critically ill patients: A propensity score analysis

Introduction

The preventive association of synbiotics therapy has not been thoroughly clarified in mechanically ventilated patients. The purpose of this study was to evaluate whether synbiotics therapy has preventive association against septic complications in ventilated critically ill patients.