Thomas Hoffmann

Publications (4)17.98 Total impact

• Article: Attenuated autonomic function in multiple organ dysfunction syndrome across three age groups.

  Hendrik Schmidt, Ursula Müller-Werdan, Thomas Hoffmann, Dárrel P Francis, Massimo F Piepoli, Mathias Rauchhaus, Roland Prondzinsky, Harald Loppnow, Michael Buerke, Dirk Hoyer, Karl Werdan
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  ABSTRACT: Multiple organ dysfunction syndrome (MODS) is the failure of several organs after a trigger event. The mortality is high, at up to 70%. We hypothesize that autonomic dysfunction may substantially contribute to the development of MODS and speculate that there is an age dependence of autonomic dysfunction in MODS. A total of 90 consecutively admitted MODS patients were assigned to this study. Three variables of autonomic function were analyzed: heart rate variability (HRV), baroreflex sensitivity (BRS) and chemoreflex sensitivity (CRS). The patient cohort was divided into three age groups. The main finding was that BRS, CRS and almost all indices of HRV were attenuated in comparison to normal range data and there was no age dependence for HRV indices or CRS, but there was for BRS. In conclusion, autonomic function in MODS is attenuated. The influence of MODS on autonomic function overwhelms the age dependence of autonomic function observed in healthy subjects.
  Biomedizinische Technik 02/2006; 51(4):264-7. · 0.86 Impact Factor
• Article: Autonomic dysfunction predicts mortality in patients with multiple organ dysfunction syndrome of different age groups.

  Hendrik Schmidt, Ursula Müller-Werdan, Thomas Hoffmann, Darrel P Francis, Massimo F Piepoli, Mathias Rauchhaus, Roland Prondzinsky, Harald Loppnow, Michael Buerke, Dirk Hoyer, Karl Werdan
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  ABSTRACT: Multiple organ dysfunction syndrome (MODS) is the sequential failure of several organ systems after a trigger event, like sepsis or cardiogenic shock. Mortality rate is high, up to 70%. Autonomic dysfunction may substantially contribute to the development of MODS. Our study aimed to characterize a) the spectrum of autonomic dysfunction of critically ill MODS patients; b) whether autonomic dysfunction is different in patients receiving sedation, mechanical ventilation, or catecholamines; c) the age dependency of autonomic dysfunction in MODS; and d) whether autonomic dysfunction predicts mortality in MODS. Prospective cohort study. Twelve-bed medical intensive care unit in a university center. Ninety consecutively admitted score-defined MODS patients. Assessment of heart rate variability, baroreflex sensitivity, and chemoreflex sensitivity as markers of autonomic dysfunction. The patients were followed for 28-day mortality. Baroreflex sensitivity, chemoreflex sensitivity, and almost all indexes of heart rate variability were attenuated in comparison to normal range data. There was no association between the assessed heart rate variability variables, baroreflex sensitivity or chemoreflex sensitivity, and the presence of sedation or catecholamine therapy. Except for frequency-domain variables, pNN50 (percentage of differences of successive RR intervals differing >50 msecs) and rMSSD (root mean square of successive difference of N-N intervals), none of the measured variables were related to the presence of mechanical ventilation. Age dependency was detected for baroreflex sensitivity but not for heart rate variability indexes or chemoreflex sensitivity (across ages 24-96 yrs). lnVLF predicted 28-day mortality best in the entire cohort of patients and in a subgroup of patients with cardiogenic-triggered MODS. Autonomic function of MODS patients is blunted, and this attenuation has prognostic implications. The extensive influence of MODS on autonomic function overwhelms and masks the well-known age dependency of autonomic function seen in healthy persons.
  Critical Care Medicine 10/2005; 33(9):1994-2002. · 6.33 Impact Factor
• Article: Impaired chemoreflex sensitivity in adult patients with multiple organ dysfunction syndrome--the potential role of disease severity.

  Hendrik Schmidt, Ursula Müller-Werdan, Sebastian Nuding, Thomas Hoffmann, Darrel P Francis, Dirk Hoyer, Mathias Rauchhaus, Karl Werdan
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  ABSTRACT: The cardiac chemoreflex sensitivity is a powerful predictor of autonomic dysfunction in chronic heart failure and after myocardial infarction. The objective of the present study was to characterize cardiac chemoreflex sensitivity in patients with multiple organ dysfunction syndrome (MODS). We also aimed to elucidate the effect of the severity of MODS on the assessment of cardiac chemoreflex sensitivity. Prospective cohort study. Twelve-bed medical intensive care unit in a university center. Forty consecutively admitted patients with MODS during a 7-month period. Patients with MODS were identified by an APACHE II score of 20 or more. Sepsis was defined as a Sepsis Score, according to Elebute and Stoner, of 12 or more. The cardiac chemoreflex sensitivity was assessed using the regression of heart interval (ms) versus arterial oxygen pressure (mmHg). First, we established a new method to assess cardiac chemoreflex sensitivity and applied it to healthy controls and patients. Second, we found that cardiac chemoreflex sensitivity correlated with the severity of MODS as calculated by the APACHE II score ( r(2)=0.34, p=0.001). This relation was best fitted by a model including minimum heart rate and standard bicarbonate in 24 h ( r(2)=0.5, p<0.001) and Glasgow Coma Scale ( r(2)=0.5, p=0.005). Age, however, did not significantly contribute ( r(2)=0.001, p=0.8). The calculation of cardiac chemoreflex sensitivity enabled us to quantify an important component of the cardiorespiratory interactions in patients with MODS. Severity of illness was a more pronounced determinant of impaired cardiac chemoreflex sensitivity than age. The quantification of the cardiorespiratory interactions by measuring the cardiac chemoreflex sensitivity has potential to identify a subgroup of patients with worse prognosis.
  Intensive Care Medicine 04/2004; 30(4):665-72. · 5.40 Impact Factor
• Article: Impaired chemoreflex sensitivity in adult patients with multiple organ dysfunction syndrome—the potential role of disease severity

  Hendrik Schmidt, Ursula Müller-Werdan, Sebastian Nuding, Thomas Hoffmann, DarrelP. Francis, Dirk Hoyer, Mathias Rauchhaus, Karl Werdan
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  ABSTRACT: ObjectiveThe cardiac chemoreflex sensitivity is a powerful predictor of autonomic dysfunction in chronic heart failure and after myocardial infarction. The objective of the present study was to characterize cardiac chemoreflex sensitivity in patients with multiple organ dysfunction syndrome (MODS). We also aimed to elucidate the effect of the severity of MODS on the assessment of cardiac chemoreflex sensitivity.DesignProspective cohort study.SettingTwelve-bed medical intensive care unit in a university center.PatientsForty consecutively admitted patients with MODS during a 7-month period. Patients with MODS were identified by an APACHE II score of 20 or more. Sepsis was defined as a Sepsis Score, according to Elebute and Stoner, of 12 or more.InterventionsThe cardiac chemoreflex sensitivity was assessed using the regression of heart interval (ms) versus arterial oxygen pressure (mmHg).Measurements and resultsFirst, we established a new method to assess cardiac chemoreflex sensitivity and applied it to healthy controls and patients. Second, we found that cardiac chemoreflex sensitivity correlated with the severity of MODS as calculated by the APACHE II score (r2=0.34, p=0.001). This relation was best fitted by a model including minimum heart rate and standard bicarbonate in 24h (r2=0.5, p<0.001) and Glasgow Coma Scale (r2=0.5, p=0.005). Age, however, did not significantly contribute (r2=0.001, p=0.8).ConclusionsThe calculation of cardiac chemoreflex sensitivity enabled us to quantify an important component of the cardiorespiratory interactions in patients with MODS. Severity of illness was a more pronounced determinant of impaired cardiac chemoreflex sensitivity than age. The quantification of the cardiorespiratory interactions by measuring the cardiac chemoreflex sensitivity has potential to identify a subgroup of patients with worse prognosis.
  Intensive Care Medicine 03/2004; 30(4):665-672. · 5.40 Impact Factor