Changes in cardiac output with hemodialysis relate to net volume balance and to inferior vena cava ultrasound collapsibility in critically ill patients

Abstract

Cardiac output may increase after volume administration with relative intravascular volume depletion, or after ultrafiltration (UF) with relative intravascular volume overload. Assessing relative intravascular volume using respiratory/ventilatory changes in inferior vena cava (IVC) diameters may guide volume management to optimize cardiac output in critically ill patients requiring hemodialysis (HD) and/or UF. We retrospectively studied 22 critically ill patients having relative intravascular volume assessed by IVC Collapsibility Index (IVC CI) ¼ (IVCmax-IVCmin)/IVCmax à 100%, within 24 h of cardiac output measurement, during 37 intermittent and 21 continuous HD encounters. Cardiac output increase >10% was considered significant. Net volume changes between cardiac outputs were estimated from "isonatremic volume equivalent" (0.9% saline) gains and losses. Cardiac output increased >10% in 15 of 42 encounters with IVC CI <20% after net volume removal, and in 1 of 16 encounters with IVC CI !20% after net volume administration (p ¼ 0.0136). All intermittent and continuous HD encounters resulted in intradialytic hypotension. Net volume changes between cardiac output measurements were significantly less (median þ1.0 mL/kg) with intractable hypotension or vasopressor initiation, and net volume removal was larger (median À22.9 mL/kg) with less severe intradialytic hypotension (p < 0.001). Cardiac output increased >10% more frequently with least severe intradialytic hypotension and decreased with most severe intradialytic hypotension (p ¼ 0.047). In summary, cardiac output may increase with net volume removal by ultrafiltration in some critically ill patients with relative intravascular volume overload assessed by IVC collapsibility. Severe intradialytic hypotension may limit volume removal with ultrafiltration, rather than larger volume removal causing severe intradialytic hypotension.

<p>Comparison of Respiratory Variations of Subclavian Vein and Inferior Vena Cava in Hospitalized Patients with Kidney Disease</p>

“… 3 IVC variability by ultrasound allows a dynamic non-invasive point-of-care estimate of relative intravascular volume. Greater IVC variation predicts an increase in cardiac output in response to volume administration in patients with relative intravascular volume depletion with reasonable sensitivity and specificity, 3 , 4 , 6–8 and lesser variation is associated with the ability to remove volume by ultrafiltration 9 or to increase cardiac output in response to volume removal 10 in kidney disease patients with relative intravascular volume overload.…”

Comparison of subclavian vein to inferior vena cava collapsibility by ultrasound in acute heart failure: A pilot study

“…Ultrasound measurements of IVC CI have been used to assess relative intravascular volume overload in patients with congestive heart failure 6,7,13–15 and/or renal failure 16,17 and to predict which patients may benefit from volume removal. An IVC CI of <20% was related to the ability to remove volume by ultrafiltration 16 and/or increase cardiac output after volume removal 17 in renal failure. In patients with shortness of breath due to various etiologies, IVC CI was greater in nonheart failure (46%) than in heart failure (9.6%) patients ( p < .0001) 13 .…”

Role of Point of Care Ultrasonography in Patients with COVID-19 Associated Acute Kidney Injury

“…Inferior vena cava imaged with a curvilinear probe (C5 Philips Lumify TM ) from a subxiphoid approach. and this remains true in COVD-19 [32,33]. Shamsah et al performed a prospective observational study of echocardiography in critically patients with COVID-19.…”