Pneumologie 2011; 65 - V292
DOI: 10.1055/s-0031-1272144

Influence of Patient Position on Hemodynamic Assessment during Right Heart Catherisation in PAH

S Czekay 1, T Bollmann 1, K Lau 2, M Albers 2, C Kähler 3, R Ewert 1
  • 1Ernst Moritz Arndt-Universität Greifswald Innere Medizin B, Bereich Pneumologie/Infektiologie – Greifswald
  • 2Ernst-Moritz-Arndt Universität Greifswald Institut für Community Medicine, SHIP/Klinisch-Epidemiologische Forschung – Greifswald
  • 3Medizinische Universität Innsbruck, Department für Innere Medizin

The diagnosis of pulmonary arterial hypertension (PAH) depends on hemodynamic parameters assessed during right heart catheterization (RHC). Besides being essential for diagnosis important information on severity of the hemodynamic impairment, too, can be assessed. Currently, two methods are recommended: the direct Fick and the thermodilution method. Hoeper et al. reported that both methods are equal value in PAH patients. However, nothing is known on the influence of the patient position on hemodynamic parameters.

18 patients (11 females; age 57±10; mPAP 50±11) and 9 controls (4 females; age 58±14; mPAP 11±2) were evaluated between 2005 and 2010at the Pneumology Unit at Greifswald University. 78% of the patients revealed the diagnosis of an idiopathic PAH (n=14), 22% suffered from PAH associated to connective tissue diseases (n=4). RHC was performed in each individual in supine and 45° position and cardiac output (CO) and stroke volume (SV) calculated.

Patients and controls did not differ in age, gender, BSA and heart rate. CO was comparable at rest between both cohorts. At supine position CO obtained by thermodilution (COThermo) in PAH patients and controls were 4.6±0.9 and 5.3±1.4 L/min, respectively. The indirect Fick method revealed a CO (COFick) being significantly lower than COThermo revealing a bias of –10.7±24.9% (–0.5±1.2 L/min) at 0° and –19.4±17.9% (–0.8±0.8 L/min) at 45°. AVDO2 differed between both positions with an increase at 45° from 5.0±1.2 to 5.6±1.1. Direct comparison of COThermo at 0° with 45° by agreement analysis revealed a bias of only 3.2±11.0% (0.2±0.5 L/min). These observations were consistent in PAH patients (bias 1.1±1.4%; 0.1±0.5 L/min).

RHC and simultaneous cardiopulmonary exercise test is used in several screening programs for PAH. The thermodilution method can be recommended for RHC investigations performed in 45° position as CO is reproducible and comparable to supine position.