Harald Herkner

Meta‐analysis: ARFI elastography versus transient elastography for the evaluation of liver fibrosis

This meta‐analysis aims to compare the diagnostic performance of acoustic radiation force impulse (ARFI) elastography and transient elastography (TE) in the assessment of liver fibrosis using liver biopsy (LB) as ‘gold‐standard’.

Real-Time Continuous Glucose Monitoring in Critically Ill Patients: A prospective randomized trial

OBJECTIVE To evaluate the impact of real-time continuous glucose monitoring (CGM) on glycemic control and risk of hypoglycemia in critically ill patients. RESEARCH DESIGN AND METHODS A total 124 patients receiving mechanical ventilation were randomly assigned to the real-time CGM group (n = 63; glucose values given every 5 min) or to the control group (n = 61; selective arterial glucose measurements according to an algorithm; simultaneously blinded CGM) for 72 h. Insulin infusion rates were guided according to the same algorithm in both groups. The primary end point was percentage of time at a glucose level <110 mg/dl. Secondary end points were mean glucose levels and rate of severe hypoglycemia (<40 mg/dl). RESULTS Percentage of time at a glucose level <110 mg/dl (59.0 ± 20 vs. 55.0 ± 18% in the control group, P = 0.245) and the mean glucose level (106 ± 18 vs. 111 ± 10 mg/dl in the control group, P = 0.076) could not be improved using real-time CGM. The rate of severe hypoglycemia was lower in the real-time CGM group (1.6 vs. 11.5% in the control group, P = 0.031). CGM reduced the absolute risk of severe hypoglycemia by 9.9% (95% CI 1.2–18.6) with a number needed to treat of 10.1 (95% CI 5.4–83.3). CONCLUSIONS In critically ill patients, real-time CGM reduces hypoglycemic events but does not improve glycemic control compared with intensive insulin therapy guided by an algorithm.

Arterial Blood Pressure After Human Cardiac Arrest and Neurological Recovery

Background and Purpose In animal cardiac arrest studies, outcome has been improved by inducing arterial hypertension early after return of spontaneous circulation. The aim of our study was to evaluate whether arterial blood pressure within the first minutes and hours after return of spontaneous circulation influences neurological recovery in human cardiac arrest survivors. Methods Of 136 retrospectively evaluated patients after sudden cardiac death, two groups were defined: group 1, mean arterial blood pressure (MABP) within 5 minutes after return of spontaneous circulation above 100 mm Hg; group 2, MABP of 100 mm Hg or less. Thereafter MABP was measured every 5 minutes until 2 hours after return of spontaneous circulation. The groups were compared in regard to age, sex, in/out of hospital, witnessed/not witnessed, first electrocardiographic rhythm, time from cardiac arrest to beginning of life support and to return of spontaneous circulation, cumulative epinephrine dose administered, and best neurologica...

Accuracy of oscillometric blood pressure measurement according to the relation between cuff size and upper-arm circumference in critically ill patients.

Objective: To evaluate the accuracy of oscillometric blood pressure measurement according to the relation between cuff size and upper‐arm circumference in critically ill patients. Design: Prospective data collection. Setting: Emergency department in a 2,000‐bed inner city hospital. Patients: Thirty‐eight patients categorized into three groups according to their upper‐arm circumference (group I: 18‐25 cm; group II: 25.1‐33 cm; and group III: 33.1‐47.5 cm) were enrolled in the study protocol. Interventions: In each patient, all three cuff sizes (Hewlett‐Packard Cuff 40401 B, C, and D) were used to perform an oscillometric blood pressure measurement at least within 3 mins until ten to 20 measurements for each cuff size were achieved. Invasive mean arterial blood pressure measurement was done by cannulation of the contralateral radial artery with direct transduction of the systemic arterial pressure waveform. The corresponding invasive blood pressure value was obtained at the end of each oscillometric measurement. Measurement and Main Results: Overall, 1,494 pairs of simultaneous oscillometric and invasive blood pressure measurements were collected in 38 patients (group I, n = 5; group II, n = 23; and group III, n = 10) over a total time of 72.3 hrs. Mean arterial blood pressure ranged from 35 to 165 mm Hg. The overall discrepancy between oscillometric and invasive blood pressure measurement was −6.7 ± 9.7 mm Hg (p < .0001), if the recommended cuff size according to the upper‐arm circumference was used (539 measurements). Of all the blood pressure measurements, 26.4% (n = 395) had a discrepancy of ≥10 mm Hg and 34.2% (n = 512) exhibited a discrepancy of ≥20 mm Hg. No differences between invasive and noninvasive blood pressure measurements were noted in patients either with or without inotropic support (−6.6 + 7.2 vs. −8.6 + 6.8 mm Hg; not significant). Conclusion: The oscillometric blood pressure measurement significantly underestimates arterial blood pressure and exhibits a high number of measurements out of the clinically acceptable range. The relation between cuff size and upper‐arm circumference contributes substantially to the inaccuracy of the oscillometric blood pressure measurement. Therefore, oscillometric blood pressure measurement does not achieve adequate accuracy in critically ill patients.

Relationship between time to target temperature and outcome in patients treated with therapeutic hypothermia after cardiac arrest

IntroductionOur purpose was to study whether the time to target temperature correlates with neurologic outcome in patients after cardiac arrest with restoration of spontaneous circulation treated with therapeutic mild hypothermia in an academic emergency department.MethodsTemperature data between April 1995 and June 2008 were collected from 588 patients and analyzed in a retrospective cohort study by observers blinded to outcome. The time needed to achieve an esophageal temperature of less than 34°C was recorded. Survival and neurological outcomes were determined within six months after cardiac arrest.ResultsThe median time from restoration of spontaneous circulation to reaching a temperature of less than 34°C was 209 minutes (interquartile range [IQR]: 130-302) in patients with favorable neurological outcomes compared to 158 min (IQR: 101-230) (P < 0.01) in patients with unfavorable neurological outcomes. The adjusted odds ratio for a favorable neurological outcome with a longer time to target temperature was 1.86 (95% CI 1.03 to 3.38, P = 0.04).ConclusionsIn comatose cardiac arrest patients treated with therapeutic hypothermia after return of spontaneous circulation, a faster decline in body temperature to the 34°C target appears to predict an unfavorable neurologic outcome.

Factors influencing the accuracy of oscillometric blood pressure measurement in critically ill patients.

ObjectiveComparison of oscillometric blood pressure measurement with two different devices (M3000A using a new algorithm and M1008A using an established algorithm, both Hewlett Packard) and evaluation of current recommendations concerning the relation between cuff size and upper arm circumference in critically ill patients. DesignProspective data collection. SettingEmergency department in a 2000-bed inner-city hospital. PatientsA total of 30 patients categorized into three groups according to their upper arm circumference (I, 18–25 cm; II, 25.1–33 cm; III, 33.1–47.5 cm) were enrolled in the study protocol. InterventionsIn each patient, two noninvasive blood pressure devices with three different cuff sizes were used to perform oscillometric blood pressure measurement. Invasive mean arterial blood pressure measurement was done by cannulation of the radial artery. Measurement and Main ResultsOverall, 1,011 pairs of simultaneous oscillometric and invasive blood pressure measurements were collected in 30 patients (group I, n = 10; group II, n = 10; group III, n = 10). The overall discrepancy between both methods with the M3000A was −2.4 ± 11.8 mm Hg (p < .0001) and, with the M1008A, −5.3 ± 11.6 mm Hg (p < .0001) if the recommended cuff size according to the upper arm circumference was used (352 measurements). If smaller cuff sizes than recommended were used (308 measurements performed in group II and III), the overall discrepancy between both methods with the M3000A was 1.3 ± 13.4 mm Hg (p < .024) and, with the M1008A, −2.3 ± 11.5 mm Hg (p < .0001). ConclusionThe new algorithm reduced the overall bias of the oscillometric method but still showed a significant discrepancy between both methods of blood pressure measurement, primarily due to the mismatch between upper arm circumference and cuff size. The improvement of the algorithm alone could not result in a sufficient improvement of oscillometric blood pressure measurement. A reevaluation of the recommendations concerning the relation between upper arm circumference and cuff size are urgently required if oscillometric blood pressure measurement should become a reasonable alternative to intra-arterial blood pressure measurement in critically ill patients.

Accuracy and reliability of a subcutaneous continuous glucose-monitoring system in critically ill patients.

Background:Continuous glucose monitoring has been proposed to optimize glucose control in critically ill patients. To achieve strict glucose regulation, accurate and reliable continuous glucose-monitoring systems are essential. Objective:Evaluation of a subcutaneous continuous glucose-monitoring system for use in critically ill patients. Design:Pooled-data analysis of two prospective, randomized, controlled trials. Setting:An eight-bed medical intensive care unit of a university hospital. Patients:A total of 174 critically ill patients on intensive insulin therapy. Interventions:Subcutaneous continuous glucose monitoring. Measurements:Two thousand forty-five continuous glucose-monitoring system sensor glucose values were compared with arterial reference blood glucose levels, determined by a blood gas analyzer. Continuous glucose monitoring data were recorded continuously for up to 72 hrs by using a subcutaneous continuous glucose-monitoring sensor. The correlation of both methods and differences between continuous glucose-monitoring systems and reference values were calculated, as well as the conformity of continuous glucose-monitoring values with the International Organization for Standardization criteria (<0.83 mmol/L [15 mg/dL] difference for glucose values ≤4.12 mmol/L [≤75 mg/dL] and <20% difference for glucose values >4.12 mmol/L [>75 mg/dL]). Results:The Pearson correlation coefficient was 0.92, showing strong correlation between the two methods. The intraclass correlation coefficient was 0.92, indicating that 92% of the variability is due to subjects and measurement occasions. Mean difference between continuous glucose-monitoring system and reference values was −0.10 mmol/L (confidence interval: −0.13 to −0.07) (−2 mg/dL [confidence interval: −2 to −1]) (continuous glucose-monitoring system minus reference) and absolute difference 0.44 mmol/L (confidence interval: 0.41–0.47) (8 mg/dL [confidence interval: 7–8]). According to the insulin titration error grid analysis, 99.1% of continuous glucose-monitoring system values were in the acceptable treatment zone. No continuous glucose-monitoring system measurements were found in the life-threatening zone, and 92.9% of the continuous glucose-monitoring system glucose values met the International Organization for Standardization criteria. Conclusion:The subcutaneous continuous glucose-monitoring system is reliable for use in critically ill patients and showed glucose values with a strong correlation to arterial reference blood glucose levels, determined by a blood gas analyzer.

Combination of extended donor criteria and changes in the Model for End-Stage Liver Disease score predict patient survival and primary dysfunction in liver transplantation: a retrospective analysis.

Background. The purpose of this study was to analyze the impact of extended donor criteria (EDC) and of changes in the Model for End-Stage Liver Disease (MELD) score while waiting for liver-transplantation (&Dgr;-MELD) on patient survival and initial graft function. Methods. We included 386 consecutive patients with end-stage liver disease who underwent orthotopic liver transplantation at the Medical University Vienna between 1997 and 2003. Primary outcome was patient survival and secondary outcome was initial graft function. EDC included: age >60 years, >4 days intensive medical care, cold ischemia time >10 hr, need for noradrenalin >0.2 &mgr;g/kg/min or doputamin >6 &mgr;g/kg/min, a donor peak serum sodium >155 mEq/L, a donor serum creatinine >1.2 mg/100 mL, and a body mass index >30. Results. &Dgr;-MELD was significantly higher in the nonsurvivor population (P=0.01) and EDC showed a significant influence on initial graft function (P=0.01). Worsening in either &Dgr;-MELD or the presence of at least two EDC was not associated with an increased risk of primary graft dysfunction and death. Worsening in &Dgr;-MELD and the presence of at least two EDC was significantly associated with primary graft dysfunction (P=0.01) and death (P=0.008). Conclusion. The combination of a liver recipient with worsening &Dgr;-MELD and a potential donor with at least two EDC should be avoided.

Life after death: Posttraumatic stress disorder in survivors of cardiac arrest: Prevalence, associated factors, and the influence of sedation and analgesia

ObjectiveCardiac arrest is possibly one of the most traumatizing conditions for patients, but to date, its influence on psychic morbidity remains unknown. Posttraumatic stress disorder is a unique symptom configuration after an extreme event consisting of intrusion re-experiencing, avoidance and numbness, and hyperarousal symptoms. We studied a) the prevalence of posttraumatic stress disorder (PTSD) in long term survivors of cardiac arrest; b) the role of specific stress factors related to cardiac arrest for the development of PTSD; and c) the influence of sedation and analgesia during or after cardiac arrest on the occurrence of PTSD. DesignProspective, cohort study. SettingUniversity teaching hospital. PatientsAnalysis was performed in cardiac arrest survivors who were discharged with favorable neurologic outcome during an 8-yr period (1991–1999). InterventionsAll patients received the Davidson Trauma Score for the assessment of PTSD and a modified German version of the EuroQol questionnaire for assessment of quality of life. Cardiac arrest circumstances and administration of sedation and analgesia were assessed. Measurements and Main ResultsOf 1,630 initially resuscitated patients, 270 patients were discharged with good neurologic outcome. A total of 226 patients were contacted, and 143 patients (63% of all eligible patients) completed the study. Mean time from cardiac arrest to follow up was 45 months (range, 24–66). Thirty-nine patients (27%; 95% confidence interval, 21% to 35%) had a Davidson Trauma Score >40 and fulfilled criteria for PTSD. Patients with PTSD had a significantly lower quality of life. The only independent risk factor for the development of PTSD was younger age. There was no difference between patients with or without PTSD regarding the use of sedation and analgesia during or after cardiac arrest. ConclusionThe prevalence of PTSD in cardiac arrest survivors is high. Besides younger age, neither clinical factors nor the use of sedation and analgesia were associated with development of PTSD.

Impact of clopidogrel loading dose on clinical outcome in patients undergoing percutaneous coronary intervention: a systematic review and meta-analysis

Context Enhanced platelet inhibition by clopidogrel decreases the risk of ischemic events but carries a risk for a concomitant increase in bleeding. Objectives To compare the efficacy and safety of two clopidogrel loading regimens (300mg vs. 600mg) in patients undergoing percutaneous coronary intervention (PCI) at one month after start of therapy. Data sources A systematic literature search of MEDLINE, EMBASE, CENTRAL, and Web of Science databases using predefined search terms for relevant articles in any language. Study selection and data extraction Randomised controlled trials and non-randomised studies reporting adjusted effect estimates were included. Summary estimates of the risks ratios (RRs) with therapy were calculated using a random-effect model. Outcomes evaluated were combined major adverse cardiovascular events (MACE) and major bleedings. Results Seven studies met the inclusion criteria and included 25,383 patients. A 600mg clopidogrel loading was associated with a 34% relative risk reduction of MACE (RR=0.66; 95% confidence intervals CI=0.52-0.84; p<0.001). Sub-analysis revealed a 47% risk reduction of MACE in randomised trials (RR=0.53; 95%CI=0.32-0.88; p=0.01) and a 31% relative risk reduction in non-randomised trials (RR=0.69; 95%CI=0.54-0.90; p=0.005) in patients receiving 600mg loading with clopidogrel. In patients suffering from acute coronary syndrome, 600mg clopidogrel loading was associated with a 24% relative risk reduction in MACE (RR=0.76; 95%CI=0.60-0.95; p=0.02). Importantly, the 600mg clopidogrel loading dose was not associated with an increased risk of major bleedings (RR=0.91; 95%CI=0.73-1.15; p=0.44). Conclusions This meta-analysis demonstrates that intensified clopidogrel loading with 600mg reduces the rate of major cardiovascular events without increase in major bleeding compared to 300mg in patients undergoing PCI during one month follow-up.