CAROTID VELOCITY TIME INTEGRAL (VTI) AS A SURROGATE FOR FLUID RESPONSIVENESS IN PATIENTS WITH SEPTIC SHOCK

SESSION TITLE: Cardiovascular Critical Care CasesSESSION TYPE: Rapid Fire Case ReportsPRESENTED ON: 10/19/2022 12:45 pm - 1:45 pmINTRODUCTION: In a patient with shock the ability to calculate the cardiac output can provide the clinician with key information. Currently the gold standard of cardiac output (CO) is the invasive thermodilution method via a swan ganz catheter. However, echocardiography has become an invaluable tool. Determining the aortic velocity time integral (VTI) and left ventricle outflow track (LVOT) diameter, clinicians are able to calculate the cardiac output. This information can be utilized in a state of shock to determine the fluid responsiveness of a patient. However, aortic VTI can be difficult to obtain as it requires a proficient sonographer. Here we discuss the invaluable tool of the carotid velocity time integral as a surrogate of fluid responsiveness in a 53 year old patient with septic shock.CASE PRESENTATION: A 53 year old obese male with medical history of HTN and Type II DM was admitted to the ICU for septic shock secondary to pylonephritis. The patient presented to the ER with septic shock with BP 73/40 HR 125 RR 14 O2 Sat 98% on room air. The patient was altered and only alert to self. He was resuscitated with 2 L of Lactated Ringers (LR) in the ER which resulted in improvement of his shock. Once transferred to the ICU, the patient progressively become more hypotensive with a mean arterial pressure (MAP) of 55mmHg. The patient was started on norepinephrine, to maintain MAP goals >65mmHg. Norepinephrine continued to be titrated up. At this time in accordance with the new sepsis guideline dynamic measurement of cardiac function was attempted to determine if the patient could benefit from further IV fluid resuscitation. We attempted to obtain the aortic VTI from a 5 chamber apical view and LVOT diameter to calculate the CO. However given the patients BMI of 58 this proved to be extremely difficult. We opted to obtain the carotid VTI as a surrogate instead. The carotid VTI was 27.2cm. After performing a straight leg raise (SLR) of 45 degrees, carotid VTI improved by 36%, to 37cm. The patient was given 3L of LR and weaned off norepinephrine 2.5 hours later.DISCUSSION: The new surviving sepsis guidelines state that clinicians should use dynamic measurements to guide fluid resuscitation, over physical examination, or static parameters in isolation. By combining SLR with dynamic ultrasound, Marik et al was able to demonstrate that a 20% increase in carotid VTI had a sensitivity and specificity of 94% and 86% for assessing for volume responsiveness (increase of SV by 10%).CONCLUSIONS: It is well known that fluid resuscitation in sepsis is associated with improved outcomes. However excessive IVF administration is associated with increased ICU LOS and mortality. Determining fluid responsiveness in patients with shock is difficult, but carotid VTI combined with SLR not only shows high specificity and sensitivity for predicting volume response but can be performed at the bedside by most clinicians.Reference #1: Marik P et al. The use of bioreactance and carotid Doppler to determine volume responsiveness and blood flow redistribution following passive leg raising in hemodynamically unstable patients. Chest. 2013 Feb 1;143(2):364-70.Reference #2: Sadaka F, Juarez M, Naydenov S, O'Brien J. Fluid resuscitation in septicshock: the effect of increasing fluid balance on mortality. J Intensive Care Med. doi:10.1177/0885066613478899.Reference #3: Blehar DJ, Glazier S, Gaspari RJ. Correlation of corrected flow time in the carotid artery with changes in intravascular volume status. J Crit Care. 2014;29(4):486-488. doi:10.1016/j.jcrc.2014.03.025DISCLOSURES: No relevant relationships by Asher GorantlaNo relevant relationships by Krunal Patel SESSION TITLE: Cardiovascular Critical Care Cases SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/19/2022 12:45 pm - 1:45 pm INTRODUCTION: In a patient with shock the ability to calculate the cardiac output can provide the clinician with key information. Currently the gold standard of cardiac output (CO) is the invasive thermodilution method via a swan ganz catheter. However, echocardiography has become an invaluable tool. Determining the aortic velocity time integral (VTI) and left ventricle outflow track (LVOT) diameter, clinicians are able to calculate the cardiac output. This information can be utilized in a state of shock to determine the fluid responsiveness of a patient. However, aortic VTI can be difficult to obtain as it requires a proficient sonographer. Here we discuss the invaluable tool of the carotid velocity time integral as a surrogate of fluid responsiveness in a 53 year old patient with septic shock. CASE PRESENTATION: A 53 year old obese male with medical history of HTN and Type II DM was admitted to the ICU for septic shock secondary to pylonephritis. The patient presented to the ER with septic shock with BP 73/40 HR 125 RR 14 O2 Sat 98% on room air. The patient was altered and only alert to self. He was resuscitated with 2 L of Lactated Ringers (LR) in the ER which resulted in improvement of his shock. Once transferred to the ICU, the patient progressively become more hypotensive with a mean arterial pressure (MAP) of 55mmHg. The patient was started on norepinephrine, to maintain MAP goals >65mmHg. Norepinephrine continued to be titrated up. At this time in accordance with the new sepsis guideline dynamic measurement of cardiac function was attempted to determine if the patient could benefit from further IV fluid resuscitation. We attempted to obtain the aortic VTI from a 5 chamber apical view and LVOT diameter to calculate the CO. However given the patients BMI of 58 this proved to be extremely difficult. We opted to obtain the carotid VTI as a surrogate instead. The carotid VTI was 27.2cm. After performing a straight leg raise (SLR) of 45 degrees, carotid VTI improved by 36%, to 37cm. The patient was given 3L of LR and weaned off norepinephrine 2.5 hours later. DISCUSSION: The new surviving sepsis guidelines state that clinicians should use dynamic measurements to guide fluid resuscitation, over physical examination, or static parameters in isolation. By combining SLR with dynamic ultrasound, Marik et al was able to demonstrate that a 20% increase in carotid VTI had a sensitivity and specificity of 94% and 86% for assessing for volume responsiveness (increase of SV by 10%). CONCLUSIONS: It is well known that fluid resuscitation in sepsis is associated with improved outcomes. However excessive IVF administration is associated with increased ICU LOS and mortality. Determining fluid responsiveness in patients with shock is difficult, but carotid VTI combined with SLR not only shows high specificity and sensitivity for predicting volume response but can be performed at the bedside by most clinicians. Reference #1: Marik P et al. The use of bioreactance and carotid Doppler to determine volume responsiveness and blood flow redistribution following passive leg raising in hemodynamically unstable patients. Chest. 2013 Feb 1;143(2):364-70. Reference #2: Sadaka F, Juarez M, Naydenov S, O'Brien J. Fluid resuscitation in septic shock: the effect of increasing fluid balance on mortality. J Intensive Care Med. doi:10.1177/0885066613478899. Reference #3: Blehar DJ, Glazier S, Gaspari RJ. Correlation of corrected flow time in the carotid artery with changes in intravascular volume status. J Crit Care. 2014;29(4):486-488. doi:10.1016/j.jcrc.2014.03.025 DISCLOSURES: No relevant relationships by Asher Gorantla No relevant relationships by Krunal Patel