Performance of a capnodynamic method estimating effective pulmonary blood flow during transient and sustained hypercapnia.

Autor: Sigmundsson TS; Department of Perioperative Medicine and Intensive Care, Karolinska University Hospital, Stockholm, Sweden. thorir.sigmundsson@sll.se.; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden. thorir.sigmundsson@sll.se., Öhman T; Department of Perioperative Medicine and Intensive Care, Karolinska University Hospital, Stockholm, Sweden.; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden., Hallbäck M; Maquet Critical Care AB, Solna, Sweden., Redondo E; Department of Intensive Care Medicine, Hospital de Navarra, Pamplona, Spain., Sipmann FS; Hedenstierna's laboratory, Section of Anaesthesiology and Critical Care, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.; CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain., Wallin M; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.; Maquet Critical Care AB, Solna, Sweden., Oldner A; Department of Perioperative Medicine and Intensive Care, Karolinska University Hospital, Stockholm, Sweden.; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden., Hällsjö Sander C; Department of Perioperative Medicine and Intensive Care, Karolinska University Hospital, Stockholm, Sweden.; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden., Björne H; Department of Perioperative Medicine and Intensive Care, Karolinska University Hospital, Stockholm, Sweden.; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
Jazyk: angličtina
Zdroj: Journal of clinical monitoring and computing [J Clin Monit Comput] 2018 Apr; Vol. 32 (2), pp. 311-319. Date of Electronic Publication: 2017 May 11.
DOI: 10.1007/s10877-017-0021-3
Abstrakt: The capnodynamic method is a minimally invasive method continuously calculating effective pulmonary blood flow (CO EPBF ), equivalent to cardiac output when intra pulmonary shunt flow is low. The capnodynamic equation joined with a ventilator pattern containing cyclic reoccurring expiratory holds, provides breath to breath hemodynamic monitoring in the anesthetized patient. Its performance however, might be affected by changes in the mixed venous content of carbon dioxide (C v CO 2 ). The aim of the current study was to evaluate CO EPBF during rapid measurable changes in mixed venous carbon dioxide partial pressure (P v CO 2 ) following ischemia-reperfusion and during sustained hypercapnia in a porcine model. Sixteen pigs were submitted to either ischemia-reperfusion (n = 8) after the release of an aortic balloon inflated during 30 min or to prolonged hypercapnia (n = 8) induced by adding an instrumental dead space. Reference cardiac output (CO) was measured by an ultrasonic flow probe placed around the pulmonary artery trunk (CO TS ). Hemodynamic measurements were obtained at baseline, end of ischemia and during the first 5 min of reperfusion as well as during prolonged hypercapnia at high and low CO states. Ischemia-reperfusion resulted in large changes in P v CO 2 , hemodynamics and lactate. Bias (limits of agreement) was 0.7 (-0.4 to 1.8) L/min with a mean error of 28% at baseline. CO EPBF was impaired during reperfusion but agreement was restored within 5 min. During prolonged hypercapnia, agreement remained good during changes in CO. The mean polar angle was -4.19° (-8.8° to 0.42°). Capnodynamic CO EPBF is affected but recovers rapidly after transient large changes in P v CO 2 and preserves good agreement and trending ability during states of prolonged hypercapnia at different levels of CO.
Databáze: MEDLINE
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