POCUS of Caudal Vena Cava in Dogs

Student Information:

  • Name: Dr. Mardam Bhaskar Lakshman

  • ID No: DDM 24005(DUS)

  • Diploma: Small Animal Diagnostic Ultrasound (PGDDUS)

  • Date of Admission: 11 November 2024

  • Place of Work: Madras Veterinary College

Title of Work:

  • Point of Care Ultrasonography (POCUS) of Caudal Vena cava (CVC) and Caudal Vena cava Collapsibility Index (CVCCI) in Dogs

Objectives:

  • Point of Care assessment of Caudal Vena cava in Healthy and Dehydrated Dogs

  • To evaluate the utility of Caudal Vena cava Collapsibility index as a predictive and monitoring tool in Dogs.

Practical Utility:

  • Point-of-Care Ultrasound (POCUS) in veterinary clinical practice is emerging and advances the quality of care and therapeutic planning.

  • POCUS is used for assessing the caudal vena cava (CVC) and the caudal vena cava collapsibility index (CVCCI) in dogs, especially in emergency and critical care settings.

  • It aids in fluid resuscitation and its monitoring in critically ill dogs.

  • POCUS provides rapid, non-invasive, and dynamic assessment of intravascular volume status.

  • It is valuable for guiding fluid therapy, monitoring hemodynamic changes, and evaluating cardiovascular function.

  • Ultrasonographic evaluation of the CVC provides real-time insights into volume depletion, fluid responsiveness, and venous congestion, which helps in better recovery of small animal patients.

Review of Literature:

  • Point-of-Care Ultrasound (POCUS) is a focused, bedside ultrasound examination performed to obtain real-time diagnostic information and guide clinical decision-making.

  • POCUS has become an invaluable tool in veterinary medicine, especially in emergency and critical care, because of its speed, non-invasiveness, and accessibility (Pelchat J et al.,2020).

  • POCUS is an essential tool for hemodynamic monitoring, fluid assessment, and cardiac evaluation in veterinary medicine because it provides real-time, non-invasive insights into cardiovascular function and volume status.

  • For hemodynamic monitoring, POCUS allows clinicians to evaluate vascular filling, cardiac output, and perfusion by assessing the caudal vena cava (CVC) diameter and collapsibility index (CVCCI), left atrial-to-aortic ratio (LA/Ao), and Doppler-derived blood flow parameters (Darnis et al., 2018).

  • The CVC diameter and CVCCI are widely used to estimate intravascular volume and guide fluid therapy (Nagi et al.,2021).

  • For fluid assessment, POCUS is superior to traditional methods like central venous pressure (CVP) measurement, as it can rapidly determine the need for fluid resuscitation and prevent both under-resuscitation and fluid overload, particularly in patients with sepsis, dehydration, or hemorrhagic shock.

  • The caudal vena cava was examined using a right transhepatic window approach, with the transducer carefully placed between the right caudal lung lobe and the right kidney, minimizing patient compression.

  • The probe position was adjusted until the vena cava was visualized in the longitudinal axis.

  • Measurements were obtained using echocardiographic M-mode at 1.5 to 2 cm caudal to the right hepatic vein insertion into the caudal vena cava.

  • The CVCCI is a dynamic parameter reflecting the respiratory variations in CVC diameter, calculated as the maximum (expiratory) and minimum (inspiratory) diameters were measured using the inner method, excluding endothelial borders.

  • The CVCCI was calculated using the formula [(CVCD-max – CVCD-min) / CVCD-max] × 100 (Giraud L et al.,2022)

  • Hypovolemic patients have wide changes in CVC diameter between expiration and inspiration (>60%).

  • In euvolemic patients, the CVC width will vary between inspiration and expiration by roughly 20-60%.

  • The CVC becomes fat, not changing much (<20%) between inspiration and expiration in hypervolemic patients and in patients with increased right atrial pressure (Donopati et al., 2020).

Broad Outline of Work:

  • Dogs presented to the Madras Veterinary College Teaching Hospital with clinical signs suggestive of dehydration/shock will be evaluated in this study.

  • Selected cases will undergo detailed assessment, and animals with dehydration will be subjected to measurement of CVC and CVCCI dimensions; the values obtained will be statistically analyzed and interpreted.

Duration:

  • One semester

Location of Work:

  • Madras Veterinary College, Chennai

Budget:

  • Department Budget Supports

References:

  • Pelchat J, Chalhoub S, Boysen SR. The use of veterinary point-of-care ultrasound by veterinarians: A nationwide Canadian survey. Can Vet J. 2020 Dec;61(12):1278-1282. PMID: 33299243; PMCID: PMC7659883.

  • Darnis E, Boysen S, Merveille AC, Desquilbet L, Chalhoub S, Gommeren K. Establishment of reference values of the caudal vena cava by fast-ultrasonography through different views in healthy dogs. J Vet Intern Med. 2018 Jul;32(4):1308-1318. doi: 10.1111/jvim.15136. Epub 2018 May 10. PMID: 29749656; PMCID: PMC6060313.

  • Nagi, A.I., Shafik, A.M., Fatah, A.M.A. et al. Inferior vena cava collapsibility index as a predictor of fluid responsiveness in sepsis-related acute circulatory failure. Ain-Shams J Anesthesiol 13, 75 (2021)

  • Donati PA, Guevara JM, Ardiles V, Guillemi EC, Londoño L, Dubin A. Caudal vena cava collapsibility index as a tool to predict fluid responsiveness in dogs. J Vet Emerg Crit Care. 2020; 30: 677–686.

  • Giraud L, Fernandes Rodrigues N, Lekane M, Farnir F, Kennedy C, Gommeren K, Merveille AC. Caudal vena cava point-of-care ultrasound in dogs with degenerative mitral valve disease without clinically important right heart disease. J Vet Cardiol. 2022 Jun;41:18-29.

Advisory Committee:

  • Chairman: Dr. P. Selvaraj, Professor and Head, Veterinary University Peripheral Hospital, Madhavaram Milk Colony, Chennai-600051.

  • Member 1: Dr. M. Shiju Simon, Assistant Professor, Department of Veterinary Clinics Madras Veterinary College, Chennai-600007.

  • Member 2: Dr. J. Umamageswari, Assistant Professor, Department of Veterinary Gynaecology and Obstertrics, Madras Veterinary College, Chennai-600007.

Correspondence:

  • From: Dr. G. Vijaykumar, Ph.D., Professor and Head, Department of Veterinary Clinics, Madras Veterinary College, Chennai 600 007

  • To: The Director of Distance Education, TANUVAS, Chennai 600 051

  • Subject: PG Diploma I Semester –Small Animal Diagnostic Ultrasound (PGDDUS). Dr. Mardam Bhaskar Lakshman ID No: DDM 24005(DUS) Proposal for Programme of Research Work –Submission