Respiratory Variation in Carotid Artery Peak Systolic Velocity Is Unable to Predict Fluid Responsiveness in Spontaneously Breathing Critically Ill Patients When Assessed by Novice Physician Sonologists

Abstract

Background: Respiratory variation in carotid artery peak systolic velocity (ΔVpeak) assessed by point-of-care ultrasound (POCUS) has been proposed as a noninvasive means to predict fluid responsiveness. We aimed to evaluate the ability of carotid ΔVpeak as assessed by novice physician sonologists to predict fluid responsiveness. Methods: This study was conducted in 2 intensive care units. Spontaneously breathing, nonintubated patients with signs of volume depletion were included. Patients with atrial fibrillation/flutter, cardiogenic, obstructive or neurogenic shock, or those for whom further intravenous (IV) fluid administration would be harmful were excluded. Three novice physician sonologists were trained in POCUS assessment of carotid ΔVpeak. They assessed the carotid ΔVpeak in study participants prior to the administration of a 500 mL IV fluid bolus. Fluid responsiveness was defined as a ≥10% increase in cardiac index as measured using bioreactance. Results: Eighty-six participants were enrolled, 50 (58.1%) were fluid responders. Carotid ΔVpeak performed poorly at predicting fluid responsiveness. Test characteristics for the optimum carotid ΔVpeak of 8.0% were: area under the receiver operating curve = 0.61 (95% CI: 0.48-0.73), sensitivity = 72.0% (95% CI: 58.3-82.56), specificity = 50.0% (95% CI: 34.5-65.5). Conclusions: Novice physician sonologists using POCUS are unable to predict fluid responsiveness using carotid ΔVpeak. Until further research identifies key limiting factors, clinicians should use caution directing IV fluid resuscitation using carotid ΔVpeak.

Role of carotid corrected flow time and peak velocity variation in predicting fluid responsiveness: a systematic review and meta-analysis

“…A study by Abbasi et al [ 23 ] showed that novice sonologists are unable to determine fluid responsiveness based on changes in FTc or carotid blood flow. Another study [ 24 ] showed that ΔVpeak could not accurately predict fluid responsiveness when evaluated by novice sonologists. These studies suggest that some level of expertise may be required to correctly evaluate carotid ultrasound-derived FTc and ΔVpeak to determine fluid responsiveness.…”

Questioning the Role of Carotid Artery Ultrasound in Assessing Fluid Responsiveness in Critical Illness: A Systematic Review and Meta-Analysis

“…There were multiple reasons for hemodynamic instability. The majority were unspecified/heterogeneous [ 9 , 25 , 29 , 32 , 34 , 35 , 37 , 39 ] or septic shock [ 26 , 30 , 31 , 33 , 36 , 40 ], with a minority of studies having cohorts of patients with haemorrhagic shock [ 27 ] or cardiogenic shock [ 38 ]. A fluid challenge was administered either by crystalloid bolus [ 27 – 31 , 34 , 37 , 40 ], passive leg raise (PLR) [ 25 , 26 , 32 , 38 , 39 ], or a combination of the two [ 9 , 33 , 35 , 36 ].…”

“…Crystalloid volume was determined by weight (6-7 ml/kg) or a predetermined value (200 ml–500 ml). The reference standards most commonly used were left ventricular outflow tract (LVOT) velocity time integral (VTI) [ 26 , 27 , 31 , 33 , 34 , 37 , 38 ] and noninvasive cardiac output monitor (NICOM) (Cheetah Medical, Inc) [ 9 , 25 , 28 , 29 ], with some studies used pulmonary artery catheter (PAC) [ 32 , 36 , 40 ], pulse contour cardiac output (PiCCO) (PULSION Medical Systems AG, Munich, Germany) [ 30 , 35 ], and FloTrac (Edwards Lifesciences, Irvine, CA, USA) [ 39 ].…”

“…Patient cohorts who were mechanically ventilated varied significantly, ranging between 0% and 100%. Four different carotid measures were used including change in carotid doppler peak velocity (∆CDPV) [ 27 , 29 – 31 , 36 , 37 , 40 ], carotid blood flow (CBF) [ 9 , 28 , 33 , 34 , 38 ], change in carotid artery velocity time integral (∆CAVTI) [ 9 , 26 , 33 , 35 , 37 ], and carotid flow time (CFT) [ 25 , 28 , 32 , 39 , 40 ]. One study used carotid time-averaged mean velocity (TAMEAN) [ 35 ].…”

Functional Hemodynamic Monitoring With a Wireless Ultrasound Patch

“…Nevertheless, one group found that carotid artery peak velocity variation worked well in spontaneously breathing preoperative neurosurgery patients, 51 and another group could not replicate this finding in critically ill patients. 54 Conflicting Data and Sources of Error Yet, not all investigations have confirmed the common carotid artery as a successful site to infer SV change. Girotto et al found that carotid blood flow was sensitive but not specific for detecting significant change in cardiac index (CI), 55 and Abbasi et al found that novice sonographers were unable to use either carotid blood flow or FTc as adequate CI surrogates.…”