Derk Olthoff

Intensive Insulin Therapy and Pentastarch Resuscitation in Severe Sepsis

BACKGROUND The role of intensive insulin therapy in patients with severe sepsis is uncertain. Fluid resuscitation improves survival among patients with septic shock, but evidence is lacking to support the choice of either crystalloids or colloids. METHODS In a multicenter, two-by-two factorial trial, we randomly assigned patients with severe sepsis to receive either intensive insulin therapy to maintain euglycemia or conventional insulin therapy and either 10% pentastarch, a low-molecular-weight hydroxyethyl starch (HES 200/0.5), or modified Ringers lactate for fluid resuscitation. The rate of death at 28 days and the mean score for organ failure were coprimary end points. RESULTS The trial was stopped early for safety reasons. Among 537 patients who could be evaluated, the mean morning blood glucose level was lower in the intensive-therapy group (112 mg per deciliter [6.2 mmol per liter]) than in the conventional-therapy group (151 mg per deciliter [8.4 mmol per liter], P<0.001). However, at 28 days, there was no significant difference between the two groups in the rate of death or the mean score for organ failure. The rate of severe hypoglycemia (glucose level, < or = 40 mg per deciliter [2.2 mmol per liter]) was higher in the intensive-therapy group than in the conventional-therapy group (17.0% vs. 4.1%, P<0.001), as was the rate of serious adverse events (10.9% vs. 5.2%, P=0.01). HES therapy was associated with higher rates of acute renal failure and renal-replacement therapy than was Ringers lactate. CONCLUSIONS The use of intensive insulin therapy placed critically ill patients with sepsis at increased risk for serious adverse events related to hypoglycemia. As used in this study, HES was harmful, and its toxicity increased with accumulating doses. (ClinicalTrials.gov number, NCT00135473.)

Assessment of the safety of recombinant tissue factor pathway inhibitor in patients with severe sepsis: a multicenter, randomized, placebo-controlled, single-blind, dose escalation study.

Objective To identify a safe and potentially effective recombinant tissue factor pathway inhibitor (rTFPI) dose for further clinical evaluation in patients with severe sepsis. Design Prospective, randomized, single-blind, placebo-controlled, dose escalation, multicenter, multinational phase II clinical trial. Setting Thirty-eight intensive care units in the United States and Europe. Patients Two hundred and ten subjects with severe sepsis who received standard supportive care and antimicrobial therapy. Interventions Subjects received a continuous intravenous infusion of placebo or rTFPI at 0.025 or 0.05 mg/kg/hr for 4 days (96 hrs). Measurements and Main Results There were no significant imbalances in demographics, severity of illness, or source of infection in patients randomized to placebo or either dose of rTFPI. A 20% relative reduction in 28-day all-cause mortality was observed when all rTFPI-treated patients were compared with all placebo patients. An improvement in pulmonary organ dysfunction score and in a composite intensive care unit score (pulmonary, cardiovascular, and coagulation) were also noted in the rTFPI-treated patients. Logistic regression modeling indicated a substantial treatment by baseline laboratory international normalized ratio (INR) interaction effect when only treatment and INR were in the model (p = .037) and when baseline Acute Physiology and Chronic Health Evaluation (APACHE II) and log10 interleukin 6 were adjusted for (p = .026). This interaction effect indicates that higher baseline INR is associated with a more pronounced beneficial rTFPI effect. There was no increase in mortality in subjects treated with either dose of rTFPI compared with placebo. Biological activity, as detected by a statistically significant reduction in thrombin-antithrombin complexes (TATc), was noted in the all rTFPI-treated patients compared with those receiving placebo. There were no major imbalances across all treatment groups with respect to safety. The frequency of adverse events (AEs) and severe adverse events (SAEs) was similar among the treatment groups, with a slight increase in SAEs and SAEs involving bleeding in the 0.05 mg/kg/hr rTFPI group. The overall incidence of AEs involving bleeding was 28% of patients in the all placebo group and 23% of patients in the all rTFPI-treated group; a slight but statistically insignificant increase in incidence of SAEs involving bleeding was observed in the all rTFPI group (9%) as compared with the all placebo group (6%;p = .39). Conclusions Although the trial was not powered to show efficacy, a trend toward reduction in 28-day all-cause mortality was observed in the all rTFPI group compared with all placebo. This study demonstrates that rTFPI doses of 0.025 and 0.05 mg/kg/hr could be safely administered to severe sepsis patients. Additionally, rTFPI demonstrated bioactivity, as shown by reduction in TATc complexes and interleukin-6 levels. These findings warrant further evaluation of rTFPI in an adequately powered, placebo controlled, randomized trial for the treatment of severe sepsis.

Prevention of postoperative nausea and vomiting by metoclopramide combined with dexamethasone: randomised double blind multicentre trial

Abstract Objectives To determine whether 10 mg, 25 mg, or 50 mg metoclopramide combined with 8 mg dexamethasone, given intraoperatively, is more effective in preventing postoperative nausea and vomiting than 8 mg dexamethasone alone, and to assess benefit in relation to adverse drug reactions. Design Four-armed, parallel group, double blind, randomised controlled clinical trial. Setting Four clinics of a university hospital and four district hospitals in Germany. Participants 3140 patients who received balanced or regional anaesthesia during surgery. Main outcome measures Postoperative nausea and vomiting within 24 hours of surgery (primary end point); occurrence of adverse reactions. Results Cumulative incidences (95% confidence intervals) of postoperative nausea and vomiting were 23.1% (20.2% to 26.0%), 20.6% (17.8% to 23.4%), 17.2% (14.6% to 19.8%), and 14.5% (12.0% to 17.0%) for 0 mg, 10 mg, 25 mg, and 50 mg metoclopramide. In the secondary analysis, 25 mg and 50 mg metoclopramide were equally effective at preventing early nausea (0-12 hours), but only 50 mg reduced late nausea and vomiting (> 12 hours). The most frequent adverse drug reactions were hypotension and tachycardia, with cumulative incidences of 8.8% (6.8% to 10.8%), 11.2% (9.0% to 13.4%), 12.9% (10.5% to 15.3%), and 17.9% (15.2% to 20.6%) for 0 mg, 10 mg, 25 mg, and 50 mg metoclopramide. Conclusion The addition of 50 mg metoclopramide to 8 mg dexamethasone (given intraoperatively) is an effective, safe, and cheap way to prevent postoperative nausea and vomiting. A reduced dose of 25 mg metoclopramide intraoperatively, with additional postoperative prophylaxis in high risk patients, may be equally effective and cause fewer adverse drug reactions. Trial registration Current Controlled Trials ISRCTN31625370

Auditory processing during deep propofol sedation and recovery from unconsciousness

OBJECTIVE Using evoked potentials, this study investigated effects of deep propofol sedation, and effects of recovery from unconsciousness, on the processing of auditory information with stimuli suited to elicit a physical MMN, and a (music-syntactic) ERAN. METHODS Levels of sedation were assessed using the Bispectral Index (BIS) and the Modified Observers Assessment of Alertness and Sedation Scale (MOAAS). EEG-measurements were performed during wakefulness, deep propofol sedation (MOAAS 2-3, mean BIS=68), and a recovery period. Between deep sedation and recovery period, the infusion rate of propofol was increased to achieve unconsciousness (MOAAS 0-1, mean BIS=35); EEG measurements of recovery period were performed after subjects regained consciousness. RESULTS During deep sedation, the physical MMN was markedly reduced, but still significant. No ERAN was observed in this level. A clear P3a was elicited during deep sedation by those deviants, which were task-relevant during the awake state. As soon as subjects regained consciousness during the recovery period, a normal MMN was elicited. By contrast, the P3a was absent in the recovery period, and the P3b was markedly reduced. CONCLUSIONS Results indicate that the auditory sensory memory (as indexed by the physical MMN) is still active, although strongly reduced, during deep sedation (MOAAS 2-3). The presence of the P3a indicates that attention-related processes are still operating during this level. Processes of syntactic analysis appear to be abolished during deep sedation. After propofol-induced anesthesia, the auditory sensory memory appears to operate normal as soon as subjects regain consciousness, whereas the attention-related processes indexed by P3a and P3b are markedly impaired. SIGNIFICANCE Results inform about effects of sedative drugs on auditory and attention-related mechanisms. The findings are important because these mechanisms are prerequisites for auditory awareness, auditory learning and memory, as well as language perception during anesthesia.

Sequential effects of increasing propofol sedation on frontal and temporal cortices as indexed by auditory event-related potentials

BackgroundIt is an open question whether cognitive processes of auditory perception that are mediated by functionally different cortices exhibit the same sensitivity to sedation. The auditory event-related potentials P1, mismatch negativity (MMN), and early right anterior negativity (ERAN) originate from different cortical areas and reflect different stages of auditory processing. The P1 originates mainly from the primary auditory cortex. The MMN is generated in or in the close vicinity of the primary auditory cortex but is also dependent on frontal sources. The ERAN mainly originates from frontal generators. The purpose of the study was to investigate the effects of increasing propofol sedation on different stages of auditory processing as reflected in P1, MMN, and ERAN. MethodsThe P1, the MMN, and the ERAN were recorded preoperatively in 18 patients during four levels of anesthesia adjusted with target-controlled infusion: awake state (target concentration of propofol 0.0 &mgr;g/ml), light sedation (0.5 &mgr;g/ml), deep sedation (1.5 &mgr;g/ml), and unconsciousness (2.5–3.0 &mgr;g/ml). Simultaneously, propofol anesthesia was assessed using the Bispectral Index. ResultsPropofol sedation resulted in a progressive decrease in amplitudes and an increase of latencies with a similar pattern for MMN and ERAN. MMN and ERAN were elicited during sedation but were abolished during unconsciousness. In contrast, the amplitude of the P1 was unchanged by sedation but markedly decreased during unconsciousness. ConclusionThe results indicate differential effects of propofol sedation on cognitive functions that involve mainly the auditory cortices and cognitive functions that involve the frontal cortices.

Do Variations in the 5-ht3a and 5-ht3b Serotonin Receptor Genes ( htr3a and htr3b ) Influence the Occurrence of Postoperative Vomiting?

BACKGROUND: Postoperative nausea and vomiting are unpleasant side effects of general anesthesia. Besides known risk factors (female gender, nonsmoker, history, and opioids), a genetic influence of the serotonin receptor system on the development of nausea and vomiting has repeatedly been proposed. In this pilot study, we therefore investigated the genes of the serotonin receptor subunits A and B (HTR3A and HTR3B) for genetic variants. METHODS: We included 95 patients who had suffered from postoperative vomiting (POV) after general anesthesia and 94 control patients. After DNA isolation, the entire HTR3A and HTR3B coding regions, the 5′ flanking regions, and exon/intron boundaries were screened for genetic variants. Correlation of identified genetic variants with POV was determined by logistic regression. RESULTS: We identified 16 different variants in the HTR3A gene and 19 in the HTR3B gene. By using a multivariate logistic regression model that also included classical risk factors, the HTR3A variant c1377A>G was associated with a significantly higher risk (odds ratio [OR] 2.972; 95% confidence interval [CI] 1.466–6.021; P = 0.003) and the HTR3B variants c5+201_+202delCA (OR 0.421; 95% CI 0.257–0.69; P = 0.001) and c6-137C>T (OR 0.034; 95% CI 0.003–0.332; P = 0.004) were associated with a lower risk for POV. However, all significant genetic variants were located in noncoding regions of their gene. CONCLUSIONS: Genetic variations in the HTR3A and HTR3B gene seem to be associated with the individual risk of developing POV. How strong their influence is within the multifactorial genesis of POV needs to be investigated in additional studies with an appropriate sample size.

Transesophageal Echocardiography for Verification of the Position of the Electrocardiographically-Placed Central Venous Catheter

OBJECTIVE Compare changes in P-wave amplitude of the intra-atrial electrocardiogram (ECG) and its corresponding transesophageal echocardiography (TEE)-controlled position to verify the exact localization of a central venous catheter (CVC) tip. DESIGN A prospective study. SETTING University, single-institutional setting. PARTICIPANTS Two hundred patients undergoing elective cardiac surgery. INTERVENTIONS CVC placement via the right internal jugular vein with ECG control using the guidewire technique and TEE control in 4 different phases: phase 1: CVC placement with normalized P wave and measurement of distance from the crista terminalis to the CVC tip; phase 2: TEE-controlled placement of the CVC tip; parallel to the superior vena cava (SVC) and measurements of P-wave amplitude; phase 3: influence of head positioning on CVC migration; and phase 4: evaluation of positioning of the CVC postoperatively using a chest x-ray. MEASUREMENTS AND MAIN RESULTS The CVC tip could only be visualized in 67 patients on TEE with a normalized P wave. In 198 patients with the CVC parallel to the SVC wall controlled by TEE (phase 2), an elevated P wave was observed. Different head movements led to no significant migration of the CVC (phase 3). On a postoperative chest-x-ray, the CVC position was correct in 87.6% (phase 4). CONCLUSION The study suggests that the position of the CVC tip is located parallel to the SVC and 1.5 cm above the crista terminalis if the P wave starts to decrease during withdrawal of the catheter. The authors recommend that ECG control as per their study should be routinely used for placement of central venous catheters via the right internal jugular vein.

Functional characterization of malignant hyperthermia-associated RyR1 mutations in exon 44, using the human myotube model

Malignant hyperthermia (MH) is a pharmacogenetic disorder with an autosomal dominant inheritance. During exposure to triggering agents as volatile anaesthetics, affected individuals may develop a potentially fatal hypermetabolic syndrome caused by excessive calcium release from the sarcoplasmic reticulum in skeletal muscle. More than 60 MH associated mutations were found in the gene of skeletal muscle ryanodine receptor (RyR1), but only some of them have been functionally characterized. Primary human myotubes were cultured from carriers of RyR1 mutations in exon 44 (Ala2350Thr, Arg2355Trp, Gly2375Ala) and from MH non-susceptible individuals. Investigation of calcium homeostasis with the calcium sensitive probe Fura 2 showed a higher sensitivity to the ryanodine receptor agonists 4-chloro-m-cresol, caffeine and halothane for the myotubes derived from the mutation carriers as compared to those of the control group. The presence of RyR1 mutations with impact on calcium homeostasis emphasizes the functional significance of exon 44.

The Ile2453Thr mutation in the ryanodine receptor gene 1 is associated with facilitated calcium release from sarcoplasmic reticulum by 4-chloro-m-cresol in human myotubes

Central core disease (CCD) is a congenital disorder of skeletal muscle that is characterised histologically by typical central cores in type 1 skeletal muscle fibres. This disease is associated with malignant hyperthermia susceptibility and has been linked to the gene of skeletal muscle ryanodine receptor RYR1. In this study, we present a family with the spontaneous occurrence of the RYR1 Ile2453Thr mutation. Affected individuals were diagnosed as susceptible to malignant hyperthermia in the in vitro contracture test (IVCT) and showed histological signs of CCD. Myotubes were derived from the index patient. The calcium homeostasis in response to the ryanodine receptor agonist 4-chloro-m-cresol (4CmC) was investigated by calcium imaging using the Ca(2+)-sensitive fluorescent probe FURA 2. In the myotubes derived from the mutation carrier, the EC(50) of 4CmC was reduced to 94 micro as compared to 201 microM in a control group of 16 individuals non-susceptible to malignant hyperthermia. In the myotubes of the non-affected family members, the EC(50) was found within the same range as that of the control group. The reduction of EC(50) indicates a facilitated calcium release from sarcoplasmic reticulum in the myotubes of the index patient suggesting that the RYR1 Ile2453Thr mutation is pathogenic for the malignant hyperthermia susceptibility and CCD of the two affected individuals.

Comparative evaluation of Bispectral Index and Narcotrend Index in children below 5 years of age

Background:  The use of electroencephalogram (EEG) monitoring devices for assessing the depth of hypnosis is most difficult in children under 5 years of age.