Biomedical subjects

Christian Madl

Publications and source records attributed to Christian Madl.

7 recordsLinked to original sources

PubMed2003

Neurocognitive deficit following aortic valve replacement with biological/mechanical prosthesis.

OBJECTIVE: The aim of this study was to objectively measure neurocognitive deficit following aortic valve replacement with a mechanical or biological prosthesis. MATERIALS AND METHODS: In this prospective, contemporary study we followed 82 consecutive patients undergoing isolated aortic valve replacement with either a mechanical (n=29, mean age=52+/-7 years) or a biological (n=53, mean age=68+/-10 years) valve prosthesis. Neurocognitive function was measured by means of objective P300 auditory evoked potentials (peak latencies, ms) and two standard psychometric tests (Trailmaking Test A, Mini Mental State Examination) before the operation, 7 days and 4 months after the operation, respectively. RESULTS: Since P300 peak latencies increase with age, preoperative P300 measures are lower in patients receiving mechanical valves (360+/-35 ms, mean 52 years) as compared to patients receiving biological valves (381+/-34 ms, 68 years, P=0.0001). Seven days after surgery, P300 peak latencies were prolonged (-worsened) in both groups as compared to preoperative values (mechanical valves: 384+/-36 ms; P=0.0001 and biological valves: 409+/-39 ms; P=0.0001). Although on a different level (-age-related), this development was comparable within both groups (P=0.800). Four months after surgery, P300 peak latencies normalized in the mechanical valve group (372+/-27 ms, P=0.857 versus preoperative), while in contrast in the biological valve group they remained prolonged (417+/-37 ms, P=0.0001). We found no difference within patients receiving different types of biological or mechanical aortic valves. CONCLUSION: Postoperative neurocognitive damage is not reversible in (-elderly) patients with biological aortic valve replacement, while in contrast postoperative neurocognitive damage is reversible in (-younger) patients with mechanical valve replacement. For this contrary development, age seems to be most important, whereas damage related to type of valve prosthesis may be overestimated.

Adult↗

PubMed2003

Gastrointestinal disorders of the critically ill. Systemic consequences of ileus.

Ileus refers to the partial or complete blockage of the small and/or large intestine either by functional (adynamic or paralytic ileus) or mechanical bowel obstruction. The diffuse gastrointestinal dysmotility during functional and mechanical ileus may result in intestinal dilatation, increased luminal pressure and gut wall ischaemia which may lead to increased intra-abdominal pressure (IAP). Any type of ileus may promote abdominal fluid sequestration with severe systemic hypovolaemia, intestinal bacterial overgrowth with the evolution of bacterial translocation and systemic invasive infections and inflammation of the intestinal wall with concomitant release of cytokines and the development of the systemic inflammatory response syndrome. The most serious complications of ileus are mediated by an increase in IAP. Intra-abdominal hypertension has been found in up to 20% of critically ill patients and may lead to a broad pattern of systemic consequences with multiple organ dysfunction, including cardiovascular, hepatic, pulmonary, renal and neurological function. The abdominal compartment syndrome is an emergency condition which is defined as elevation of IAP above 20 to 25 mmHg and the presence of systemic consequences. Therapeutic considerations include the maintenance of adequate hydration status, avoidance of drugs known to impair intestinal perfusion, stimulation of gastric and intestinal motility and various nutritional aspects. Colonic tube placement after decompressive colonoscopy may be effective in reducing intestinal dilatation. In the abdominal compartment syndrome the 'open abdominal approach' with decompressive laparotomy by opening the peritoneal cavity and temporary abdominal closure is the therapy of choice.

Critical Illness↗

PubMed2002

[Recommendations for prognostic assessment of cerebral hypoxia after cardiopulmonary resuscitation--Austrian Interdisciplinary Consensus Conference].

Various clinical parameters, neurological examination models, biochemical tests, electrophysiological procedures and neuro-imaging techniques have been studied with respect to the detection of cerebral hypoxia in patients after cardiopulmonary resuscitation. These parameters were critically evaluated by the members of the Austrian interdisciplinary consensus conference. Based on the results of scientific publications, the consensus meeting identified 26 parameters, which allow the prognostic evaluation of cerebral hypoxia after cardiopulmonary resuscitation. Among these parameters, however, the strength of evidence and the level of recommendation are different.

APACHE↗

PubMed2002

Cognitive deficit after aortic valve replacement.

BACKGROUND: Impairment of cognitive brain function after coronary artery bypass grafting (CABG) is well known. In contrast the potential neurocognitive damage related to aortic valve replacement (AVR) is uncertain. METHODS: In this contemporary case-matched control study we followed 30 patients (mean age 70 years) receiving isolated AVR with a biological prosthesis. A cohort of sex-and age-matched patients (n = 30, mean age 70 years) receiving CABG with cardiopulmonary bypass served as controls. Cognitive brain function was measured by means of auditory evoked P300 potentials (peak latencies, ms) before the operation and 7 days and 4 months after the operation. Additionally, two standard psychometric tests (Mini-Mental State Examination and the Trailmaking Test A) were performed. RESULTS: In preoperative measures there was no difference between patients undergoing AVR and patients undergoing CABG (AVR 378 +/- 37 ms, CABG 374 +/- 32 ms, p = 0.629). One week after surgery P300 peak latencies were prolonged (impaired) in both groups compared with preoperative values (AVR 405 +/- 43 ms, p = 0.001; CABG 398 +/- 44 ms, p = 0.004). At this point of follow-up there was no difference between the groups (p = 0.607). Finally, 4 months after surgery P300 auditory evoked potentials returned to normal in the CABG group (380 +/- 24 ms, p = 0.940) while in contrast in the valve group they continued to become prolonged (worsened) compared with preoperative values (410 +/- 47 ms, p = 0.005). At this time of follow-up P300 peak latencies were prolonged in AVR patients as compared with CABG patients (p = 0.032). The Trailmaking Test A and Mini-Mental State Examination failed to discriminate any difference. CONCLUSIONS: Four-month impairment of cognitive brain function is more pronounced in patients undergoing biological AVR as compared with age-matched control patients undergoing CABG. Further studies are needed to clarify the potential pathologic mechanisms causing an ongoing cognitive impairment in patients with biological aortic valve prostheses.

Aged↗

PubMed2002

Subclinical impairment of brain function in chronic hepatitis C infection.

BACKGROUND/AIMS: Central nervous system abnormalities such as fatigue and depression occur more frequently in chronic hepatitis C virus (HCV) infection than in many other causes of chronic liver disease. The finding that fatigue is unrelated to activity of hepatitis or mode of infection could indicate an independent effect of HCV on brain function. This study tested the hypothesis of a subclinical cognitive dysfunction in HCV-infected patients. METHODS: One-hundred untreated HCV-RNA positive biopsy-proven patients were investigated by P300 event-related potentials, a sensitive electrophysiologic test of cognitive processing. Health-related quality of life and fatigue were assessed using the SF-36 questionnaire and the Fatigue Impact Scale, respectively. RESULTS: Cognitive brain function was subclinically impaired in the cohort of HCV-infected patients as indicated by significantly prolonged P300 latencies (P=0.01 for comparison to matched healthy subjects) and reduced P300 amplitudes (P<0.001, respectively). Seventeen of the 100 HCV-infected patients had P300 latencies outside the age-adjusted normal range. Abnormal P300 characteristics were not related to the degree of histologic or biochemical activity of hepatitis, severity of fatigue or mental health impairment. CONCLUSIONS: This study demonstrates that patients with HCV infection showed a slight but significant neurocognitive impairment, possibly indicating a further extrahepatic manifestation of chronic hepatitis C.

Adult↗

PubMed2002

Impaired subcortical and cortical sensory evoked potential pathways in septic patients.

OBJECTIVE: Sensory evoked potential (SEP) peak latencies were recorded in order to evaluate the incidence and severity of septic encephalopathy, testing the hypothesis that the occurrence of septic encephalopathy is more frequent than generally assumed. DESIGN: Prospective cohort study. SETTING: Medical intensive care unit of a university hospital. PATIENTS: Sixty-eight critically ill patients were studied within 48 hrs after the development of severe sepsis (n = 41) or septic shock (n = 27). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Septic encephalopathy was defined as prolongation of SEP peak latencies beyond the upper limit of the reference range of subcortical (N13-N20 interpeak latency) and cortical SEP pathways (N20-N70 interpeak latency), as well as asymmetry of peak latencies marked by the presence of subclinical cerebral focal signs. Subcortical SEP pathways were impaired in 34% and cortical SEP pathways in 84% of all patients. The prolongation of the cortical SEP pathway correlated with the Acute Physiology and Chronic Health Evaluation III score (r = 0.23; p <.0001). SEP peak latencies did not differ in patients with severe sepsis compared with those with septic shock. Subclinical cerebral focal signs were present in 24% of the subcortical SEP pathways and in 6% of the cortical SEP pathways. CONCLUSIONS: Septic encephalopathy occurs more frequently than generally assumed, and its severity is associated with the severity of illness. The impairment of subcortical and cortical SEP pathways was not different between patients with severe sepsis and those with septic shock.

Brain Diseases↗

PubMed2002

Neurophysiological evidence of cognitive impairment in patients without hepatic encephalopathy after transjugular intrahepatic portosystemic shunts.

OBJECTIVES: We aimed to test the hypothesis that subclinical cognitive brain dysfunction in cirrhotic patients would deteriorate after a transjugular intrahepatic portosystemic shunt (TIPS) in the absence of clinically detectable hepatic encephalopathy. METHODS: Out of 49 consecutive cirrhotic patients receiving elective TIPS for recurrent variceal hemorrhage, we identified 22 patients who were not encephalopathic and had not undergone liver transplantation at 6-month follow-up and confirmed TIPS patency by Doppler ultrasound. Patients were tested before and 6 months after TIPS implantation using event-related (P300) cognitive evoked potentials, late somatosensory median nerve (N70) potentials, and standard psychometric tests (Mini-Mental State and trailmaking test A). Twenty-two age-matched healthy subjects served as controls. RESULTS: Relative to controls, patients showed significantly impaired P300 and N70 latencies and abnormal psychometric test results at baseline. Six months after the TIPS, a further impairment of P300 latency was observed (p = 0.005), whereas no relevant changes in N70 latency and psychometric test results occurred. CONCLUSIONS: In cirrhotic patients with portal hypertension, neurophysiological signs of cognitive brain dysfunction are detectable in the absence of hepatic encephalopathy. A further subclinical deterioration of cognitive processing was observed 6 months after the TIPS. These findings demonstrate an aggravation of subclinical hepatic encephalopathy after a TIPS.

Adult↗