TITLE:
Value of Ultrasound Assessment of the Inferior Vena Cava and the Subclavian Vein in Hemodynamic Monitoring during Spinal Anesthesia
AUTHORS:
Francois Stephane Kona Ngondo, Ferdinand Ndom Ntock, Christela Iroume, Serge Ngouatna, Ben Ousman Djoubairou, Tchatat Reine, Albert Ludovic Amengle, Roddy Stephan Bengono Bengono, Junette Arlette Metogo Mbengono, Bonaventure Jemea, Paul Owono Etoundi, Jacqueline Ze Minkande
KEYWORDS:
Spinal Anesthesia, Hemodynamic Monitoring, Hypotension, Ultrasound-Guided, Inferior Vena Cava, Subclavian Vein
JOURNAL NAME:
Open Journal of Anesthesiology,
Vol.16 No.2,
February
27,
2026
ABSTRACT: Introduction: Spinal anesthesia is a locoregional anesthetic technique used for interventions below the umbilicus. Ultrasound monitoring of the inferior vena cava and the subclavian vein can reduce the incidence of hypotension following spinal anesthesia. The objective of our study was to evaluate the hemodynamic status following spinal anesthesia using ultrasound of the inferior vena cava and subclavian vein. Methods: We conducted a blinded randomized clinical study from December 2024 to July 2025, a duration of eight months, in the anesthesia unit of the Yaoundé Military Hospital. We included patients with anesthesia risk ASA I and ASA II and excluded patients with cardiovascular comorbidities, pregnant women, and those undergoing interventions with bleeding potential. We divided the participants into two groups—standard and ultrasound-guided—using a 1:1 sequence. Our dependent variables were hypotension, vasopressor dosage used, quantity of fluid before and after induction, diameters of the inferior vena cava and right subclavian vein during inspiration and expiration, collapsibility indices, and variability. Data were entered into CS Pro version 8.0 and analyzed using SPSS version 27.0. Results: A total of 80 patients were recruited for the study and divided into two groups: 40 in the ultrasound-guided group and 40 in the standard group. The sex ratio was 6.18. The mean age was 35.51 ± 14.02 years; most surgeries performed were orthopedic (42.5%), and most patients were classified as ASA 1 (93.8%). Ultrasound measurements were as follows: mean Dmin IVC 1.7 ± 0.4 cm, mean Dmax IVC 2.0 ± 0.3 cm, mean IVCCI 15.3 ± 11.5%, Dmin SCV on spontaneous breathing 0.9 ± 0.3 cm, Dmax SCV on spontaneous breathing 1.0 ± 0.3 cm, spontaneous SCVCI 9.7 ± 8.0%. Variability index SCV 0.1 ± 0.1%, Dmin SCV on deep breathing 0.8 ± 0.2 cm, Dmax SCV on deep breathing 1.1 ± 0.3 cm, SCVCI on deep breathing 25.0 ± 9.0%, SCV variability index on deep breathing 0.3 ± 0.1%. In the study population, hypotension occurred in 18.8% (n = 15), with 22.5% (n = 9) in the ultrasound-guided group versus 15% (n = 6) in the standard group (p = 0.390). The total volume of crystalloid during the intervention was 100 ± 99 ml (0 - 500 ml) in the ultrasound-guided group versus 1174.3 ± 565.7 ml (240 - 3000 ml), p Conclusion: Ultrasound measurements of the inferior vena cava and subclavian vein are beneficial for monitoring the hemodynamic state following spinal anesthesia. Our study showed a higher proportion of hypotension in the ultrasound-guided group, with no statistically significant difference between the two groups. It permits individualized fluid management based on the needs of each patient.