Armand R. J. Girbes

Central venous catheter use

Abstract Central venous catheters are being increasingly used in both intensive care units and general wards. Their use is associated with both mechanical and infectious complications. This review will focus on short- and medium-term mechanical complications of catheter placement; infectious complications will be discussed in a separate article. The most important risk factors are patient characteristics (morbidity, underlying disease and local anatomy), the expertise of the doctor performing the procedure, and nursing care. Placement aids, such as ultrasound-guided catheter insertion, are also discussed.

Induction of organ dysfunction and up-regulation of inflammatory markers in the liver and kidneys of hypotensive brain dead rats: a model to study marginal organ donors.

BACKGROUNDnMarginal donors exposed to the full array of effects induced by brain death are characterized by low success rates after transplantation. This study examined whether organs from marginal brain dead animals show any change in organ function or tissue activation making them eventually more susceptible for additional damage during preservation and transplantation.nnnMETHODSnTo study this hypothesis we first focused on effects of brain death on donor organ quality by using a brain death model in the rat. After induction of brain death, Wistar rats were ventilated for 1 and 6 hr and then killed. Sham-operated rats served as controls. Organ function was studied using standard serum parameters. Tissue activation of liver and kidney was assessed by staining of immediate early gene products (IEG: FOS, JUN), and inflammatory markers; cell adhesion molecules (Intercellular adhesion molecule-1, vascular cell adhesion molecule-1), leukocyte infiltrates (CD45, T cell receptor, CD8, CD4), and MHC class II.nnnRESULTSnDuring brain death progressive organ dysfunction was observed that coincided with a significant increase in activation of immediate early genes, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, CD45, and MHC class II versus nonbrain dead controls. In liver tissue also the markers for T cell receptor and CD8 significantly increased.nnnCONCLUSIONSnThese findings suggest that an immune activation with increased endothelial cell activation and immediate early gene expression occurs in marginal donors after brain death induction. We suggest that brain death should not longer be regarded as a given nondeleterious condition but as a dynamic process with potential detrimental effects on donor organs that could predispose grafts for increased alloreactivity after transplantation.

Effects of low-dose dopamine on renal and systemic hemodynamics during incremental norepinephrine infusion in healthy volunteers

OBJECTIVESnTo assess the effects of low-dose dopamine on norepinephrine-induced renal and systemic vasoconstriction in normotensive healthy subjects.nnnDESIGNnOn separate days, either a low-dose dopamine (4 microg/kg/min) or a placebo (5% glucose) infusion was added in a single, blinded, randomized order to incremental norepinephrine infusions of 40, 80, and 150 ng/kg/min over a 60-min period each.nnnSETTINGnOutpatient clinic of a university-affiliated hospital.nnnSUBJECTSnNormotensive healthy volunteers.nnnINTERVENTIONSnInfusions of norepinephrine and dopamine.nnnMEASUREMENTS AND MAIN RESULTSnBlood pressure and heart rate were measured with a semiautomated device, and glomerular filtration rate and effective renal plasma flow were determined with constant infusions of 125I-iothalamate and 131I-hippurate, respectively. Norepinephrine alone progressively increased mean arterial pressure to pressor levels, whereas this effect was attenuated by the addition of dopamine (p < .05 vs. norepinephrine alone). Glomerular filtration rate increased during lower norepinephrine doses and did not decrease at the highest norepinephrine dose. Addition of dopamine further increased glomerular filtration rate. Effective renal plasma flow decreased with each norepinephrine alone infusion step, but this decrease was completely prevented by concomitant dopamine infusion (p < .01 vs. norepinephrine). Sodium excretion tended to decrease with norepinephrine, but increased two- to three-fold after addition of dopamine (p < .01 vs. norepinephrine alone).nnnCONCLUSIONSnIn healthy man, norepinephrine causes a large decrease in renal plasma flow but not in glomerular filtration rate. Concomitant dopamine administration prevents this decrease in renal plasma flow, increases sodium excretion, and also attenuates the norepinephrine-induced systemic blood pressure increase. These findings warrant further clinical evaluation of the effect of concomitant low-dose dopamine and norepinephrine administration in critically ill patients.

Optimal nutrition during the period of mechanical ventilation decreases mortality in critically ill, long-term acute female patients: a prospective observational cohort study

IntroductionOptimal nutrition for intensive care patients has been proposed to be the provision of energy as determined by indirect calorimetry, and protein provision of at least 1.2 g/kg pre-admission weight per day. The evidence supporting these nutritional goals is based on surrogate outcomes and is not yet substantiated by patient oriented, clinically meaningful endpoints. In the present study we evaluated the effects of achieving optimal nutrition in ICU patients during their period of mechanical ventilation on mortality.MethodsThis was a prospective observational cohort study in a mixed medical-surgical, 28-bed ICU in an academic hospital. 243 sequential mixed medical-surgical patients were enrolled on day 3–5 after admission if they had an expected stay of at least another 5–7 days. They underwent indirect calorimetry as part of routine care. Nutrition was guided by the result of indirect calorimetry and we aimed to provide at least 1.2 g of protein/kg/day. Cumulative balances were calculated for the period of mechanical ventilation. Outcome parameters were ICU, 28-day and hospital mortality.ResultsIn women, when corrected for weight, height, Apache II score, diagnosis category, and hyperglycaemic index, patients who reached their nutritional goals compared to those who did not, showed a hazard ratio (HR) of 0.199 for ICU mortality (CI 0.048–0.831; P = 0.027), a HR of 0.079 for 28 day mortality (CI 0.013–0.467; P = 0.005) and a HR of 0.328 for hospital mortality (CI 0.113–0.952; P = 0.04). Achievement of energy goals whilst not reaching protein goals, did not affect ICU mortality; the HR for 28 day mortality was 0.120 (CI 0.027–0.528; P = 0.005) and 0.318 for hospital mortality (CI 0.107–0.945; P = 0.039). No difference in outcome related to optimal feeding was found for men.ConclusionsOptimal nutritional therapy improves ICU, 28-day and hospital survival in female ICU patients. Female patients reaching both energy and protein goals have better outcomes than those reaching only the energy goal. In the present study men did not benefit from optimal nutrition.

Drug intervention trials in sepsis: divergent results.

CONTEXTnImportant advances have been made in our understanding of severe sepsis. Outcome can be improved by targeted interventions, including early and appropriate antibiotic therapy and goal-directed resuscitation, and might be further improved by selective decontamination of the digestive tract, tight control of glucose, and possibly by giving corticosteroids to selected patients. Drugs that target specific steps in the septic cascade include cytokine inhibitors, anti-endotoxins, and the three naturally occurring anticoagulants. Only one of these trials, which assessed the efficacy of activated protein C, reported significant improvements in outcome. Translation of these results into practice has been hampered by high drug costs, and by apparent discrepancies between interim results and final outcomes in two of the trials with natural anticoagulants.nnnSTARTING POINTnRecently, Steven Opal and colleagues (Crit Care Med 2004; 32: 332-41) reported a randomised trial with platelet-activating-factor acetylhydrolase to suppress the inflammatory response in septic patients. No effects on outcome were observed (mortality 24% with placebo vs 25% with the intervention). By contrast, Jose Garnacho-Montero and colleagues, in a cohort study (Crit Care Med 2003; 31: 2742-51), saw large mortality reductions with initially appropriate choice of antibiotics in septic patients (19.8% reduction overall and 43.4% in patients with septic shock). These benefits were higher than those even in the most successful trial with an antisepsis agents, underscoring the importance of basic measures in severe sepsis. WHERE NEXT? Initial management in severe sepsis should include early goal-directed fluid resuscitation, appropriate antibiotic treatment, and surgical-site control. Intensive-care units should be run by specialists, with adequate medical and nursing staffing. Tight regulation of glucose, selective decontamination of the digestive tract, and moderate-dose corticosteroids in selected cases should be considered. Expensive new drugs, such as activated protein C, might further improve outcome, but should be considered only when organisational aspects and supportive care have been optimised.

Inter-observer variability in APACHE II scoring: effect of strict guidelines and training

Abstract. Objective: To assess the effect of strict guidelines and a rigorous training program on variability in scoring the revised Acute Physiology and Chronic Health Evaluation (APACHE II). Design and setting: Prospective survey and intervention in the surgical ICU of a university teaching hospital. Measurements: Seven experienced intensivists and nine residents determined APACHE II scores in one set of patients before and in another set 4xa0months after a rigorous training program, following strict guidelines for using the APACHE II. Results: APACHE II scores were 14.3±4.4 before the training program (n=12) and 18.9±2.4 after (n=11). Interobserver agreement rates increased significantly from 59.7% to 76.5% and the interobserver reliability coefficient (weighted κ) from 0.72 to 0.85 after our training program was implemented. The changes were significantly greater in experienced intensivists than in less experienced residents, indicating that more experienced physicians profited to a greater degree from our training program. Conclusion: Interobserver variability in APACHE II scoring decreases markedly when strict guidelines and a regular training program are implemented, particularly among more experienced physicians. However, in our study a degree of variability (10–15%) persisted even in experienced intensivists with similar training, experience, and background, suggesting that a degree of variability is inherent in APACHE II scoring.

Interobserver variability in the use of APACHE II scores

2and the simplified acute physiology score (SAPS) are widely used to assess outcome and quality of care in intensive care units. In spite of the widespread use and general acceptance of these scoring systems, there is little information on their reliability and on inter-observer variability in their use. We assessed interobserver variation during application of the most frequently used scoring system, APACHE II, in our intensive care unit. Two groups of doctors were studied: residents (n=9) with limited experience of intensive care (average: 4 months), and intensivists (7), who should be experts in the use of scoring systems. Over 6 weeks, all doctors were given the charts of ten chosen patients and asked to assess APACHE II scores. We obtained 16 APACHE II scores of each individual patient. Analysis was with Student’s unpaired t test. There was wide variability between scores (mean 14, SD 6·0; table). There were no significant differences in score variations between intensivists and residents. The largest differences arose in the interpretation of data acquired in RESEARCH LETTERS the operating room (some took these data into account; others did not). Another cause of confusion arose in the interpretation of data which were inconsistent with the general trend: for example, tachycardia which was found only once during a 24-hour period was erroneously disregarded by some doctors. The accordance of chronic health points (2 or 5) was also a frequent source of problems. We conclude that assessment of APACHE II scores in individual patients varies widely; this applies both to less experienced doctors and to experts. Use of the APACHE II scoring system requires regular training, adherence to strict guidelines, and an understanding of which data should be used and which disregarded. Assessments of quality of medical care based on these scoring systems should be viewed with some care. 1 Kollef MH, Rainey TG. The role of outcomes research in the

Preventing central venous catheter-related infection in a surgical intensive-care unit

The cumulative effect of five measures (introduction of hand disinfection with alcohol, a new type of dressing, a one-bag system for parenteral nutrition, a new intravenous connection device, and surveillance by an infection control practitioner) on central venous catheter colonization and bacteremia was studied. Colonization was significantly reduced (P<.025); the decrease in bacteremia was not statistically significant.

Assessing adrenal insufficiency of corticosteroid secretion using free versus total cortisol levels in critical illness

PurposeTo study the value of free versus total cortisol levels in assessing relative adrenal insufficiency during critical illness-related corticosteroid insufficiency.MethodsA prospective study in a mixed intensive care unit from 2004 to 2007. We consecutively included 49 septic and 63 non-septic patients with treatment-insensitive hypotension in whom an adrenocorticotropic hormone (ACTH) test (250xa0μg) was performed. Serum total and free cortisol (equilibrium dialysis), corticosteroid-binding globulin (CBG) and albumin were assessed.ResultsAlthough a low CBG resulted in a high free cortisol level relative to total cortisol, free and total cortisol and their increases were well correlated (rxa0=xa00.77–0.79, Pxa0<xa00.001). In sepsis, hypoalbuminemia did not affect total and free cortisol, and increases in total cortisol upon ACTH predicted increases in free cortisol regardless of low binding proteins. In non-sepsis, total cortisol was lower with than without hypoalbuminemia; free cortisol did not differ, since hypoalbuminemia concurred with a low CBG. Increases in total cortisol depended less on binding proteins than on raw levels. The areas under the receiver operating characteristic curve for predicting increases in free from total cortisol were 0.93–0.97 in sepsis and 0.79–0.85 in non-sepsis (Pxa0=xa00.044 or lower for sepsis vs. non-sepsis).ConclusionsAlthough the biologically active free cortisol fraction depends on binding proteins, total cortisol correlates to free cortisol in treatment-insensitive hypotension during critical illness. In sepsis, albumin is not an important binding molecule. Subnormal increments in total cortisol upon ACTH suffice in assessing relative adrenal insufficiency, particularly in sepsis.

Predicting a low cortisol response to adrenocorticotrophic hormone in the critically ill: a retrospective cohort study

IntroductionIdentification of risk factors for diminished cortisol response to adrenocorticotrophic hormone (ACTH) in the critically ill could facilitate recognition of relative adrenal insufficiency in these patients. Therefore, we studied predictors of a low cortisol response to ACTH.MethodsA retrospective cohort study was conducted in a general intensive care unit of a university hospital over a three year period. The study included 405 critically ill patients, who underwent a 250 μg ACTH stimulation test because of prolonged hypotension or need for vasopressor/inotropic therapy. Plasma cortisol was measured before and 30 and 60 min after ACTH injection. A low adrenal response was defined as an increase in cortisol of less than 250 nmol/l or a peak cortisol level below 500 nmol/l. Various clinical variables were collected at admission and on the test day.ResultsA low ACTH response occurred in 63% of patients. Predictors, in multivariate analysis, included sepsis at admission, low platelets, low pH and bicarbonate, low albumin levels, high Sequential Organ Failure Assessment score and absence of prior cardiac surgery, and these predictors were independent of baseline cortisol and intubation with etomidate. Baseline cortisol/albumin ratios, as an index of free cortisol, were directly related and increases in cortisol/albumin were inversely related to disease severity indicators such as the Simplified Acute Physiology Score II and Sequential Organ Failure Assessment score (Spearman r = -0.21; P < 0.0001).ConclusionIn critically ill patients, low pH/bicarbonate and platelet count, greater severity of disease and organ failure are predictors of a low adrenocortical response to ACTH, independent of baseline cortisol values and cortisol binding capacity in blood. These findings may help to delineate relative adrenal insufficiency and suggest that adrenocortical suppression occurs as a result of metabolic acidosis and coagulation disturbances.