Cephalic and saphenous venous blood collected by continuous heating of the paws compared with arterial blood for measurement of blood gas values in well‐perfused dogs

Abstract

Background “Arterialization” of the dorsal hand vein is well‐established in human medicine, but not in veterinary medicine. Objectives To compare cephalic and saphenous venous blood collected by continuously heating the paws to 37°C (“arterialization”), with arterial blood (AB) for measurement of blood gas variables in well‐perfused dogs. Animals Eight healthy dogs. Methods Experimental study. Fore and hind paws were continuously heated to 37°C to “arterialize” cephalic and saphenous venous blood. AB and “arterialized” cephalic and saphenous venous blood (ACV and ASV, respectively) were simultaneously collected from lightly anesthetized dogs with induced metabolic and respiratory acid‐base disorders. The pH, partial pressures of carbon dioxide (PCO2) and oxygen (PO2), bicarbonate concentration [HCO3−], and base excess (BE) were measured once in each state. Systolic blood pressure was maintained above 100 mm Hg. The AB, ACV, and ASV values were compared. Results The pH, [HCO3−], and BE values had no significant difference and good agreement, the PCO2 values had a strong correlation (correlation coefficient of .91‐1.00), and the PO2 values had a significant difference (P < .01) and poor agreement between AB and ACV, and between AB and ASV. The PCO2 values of ASV overestimated those of AB by ~3.0 mm Hg, which was considered within clinically allowable limits, while those of ACV were not within clinically allowable limits. Conclusions and Clinical Importance Under experimental conditions, the ASV samples were more identical to the AB samples than the ACV samples for pH, PCO2, [HCO3−], and BE values in well‐perfused dogs. The saphenous vein is suitable for “arterialization.”

Arterial pCO2 prediction using saphenous pCO2 in healthy mechanically ventilated dogs

“…Furthermore, compared with the clinical limits predefined by the authors in this study (± 0.1), the LOAs being included inside those limits suggests the interchangeability of venous -whether jugular or saphenous -and arterial pH. Results from this work agree with most of the studies that have been conducted in human (Bloom et al, 2014;Byrne et al, 2014;Nanjayya et al, 2020) andveterinary (Pang et al, 2009;Kadwa et al, 2022;Shiroshita et al, 2023) medicine. Variations of pH between venous and arterial values are not of clinical impact in healthy, anesthetized, mechanically ventilated dogs.…”

“…-1.90 mmHg to 10.26 mmHg). Results from this work reflect what has been reported in both human (Bloom et al, 2014;Byrne et al, 2014;Chung et al, 2019;Nanjayya et al, 2020) and veterinary (Tamura et al, 2015;Kadwa et al, 2022;Shiroshita et al, 2023) medicine, where the reported MD between venous and arterial pCO 2 ranges between 4.15 mmHg (Byrne et al, 2014) and 4.41 mmHg (Bloom et al, 2014) in humans, and between 2.00 mmHg (Kadwa et al, 2022) and 5.80 mmHg (Tamura et al, 2015) in dogs, values that are superimposable to the ones that we found in our population.…”

“…The authors' main hypothesis is that the saphenous vein is more distal than the jugular vein, hence, the saphenous vein drains tissues with lower metabolism (especially in dogs under general anesthesia) when compared to the jugular vein. Therefore, as already reported in literature, saphenous pvCO 2 could resemble paCO 2 more than jugular pvCO 2 (Shiroshita et al, 2023).…”

“…Through this procedure, pH showed no significant difference between both the VGBs and ABG. Moreover, pvCO 2 collected from the saphenous vein was considered clinically interchangeable with paCO 2 , unlike pvCO 2 collected from the cephalic vein which showed a poor agreement with paCO 2 (Shiroshita et al, 2023).…”

“…In veterinary medicine, only a few studies have been conducted to evaluate the relationship between ABG and VBG analyses in conscious and anesthetized dogs (Ilkiw et al, 1991;Atalan et al, 2008;Pang et al, 2009;Tamura et al, 2015;Kadwa et al, 2022;Shiroshita et al, 2023). Pang et al in 2009 assessed the suitability of lingual VBG for the determination of pH and pCO 2 as an alternative to ABG (collected from the dorsal pedal artery) in anesthetized dogs.…”