Introduction

The objective was to assess impact of blood donation on sublingual microcirculation.

Methods

Prospective cohort study. Seven healthy dogs were sedated for blood donation. The anesthesia protocol was butorphanol (0.3 mg/kg IV), midazolam (0.3 mg/kg IV) and alfaxalone to effect. Between 3 to 5 4-second videos of sublingual microcirculation were recorded before and after blood donation with a sidestream dark field imaging device by the same non-blinded operator. The microcirculation videos were analyzed by off-line manual analysis with a dedicated software (Automated Vascular Analysis 4.3) in order to obtain specific microcirculatory parameters: De Backer score (DB), proportion of perfused vessels (PPV), microcirculatory flow index (MFI) and heterogeneity index (HI). DB and PPV were calculated for all vessels and for small vessels (diameter <20 µm). Heart rate (HR), lactate and non-invasive systolic arterial blood pressure (SAP) were also recorded before and after blood donation. Data are presented as median (1st quartile–3rd quartile). The comparisons before/after blood donation of HR, SAP and lactate were carried out using Wilcoxon signed-rank test. To test the impact of blood donation on microcirculatory parameters, univariable linear mixed models were constructed for each microcirculatory parameter (the microcirculatory variables were used as outcomes). They included the time period (before/after blood donation) or the volume of blood collected as predictors (fixed effects) and the individuals as random effects.

Results

Median blood donation volume was 14 mL/kg (12.9–15.1). After blood donation, lactate concentration significantly decreased (before: 2.3 (2–2.8), after: 1 (0.9–1.75) mmol/l, p=0.02). HR (before: 72 (68–80), after: 92 (80–110) bpm, p=0.06) and SAP appeared unchanged after donation (before: 115 (112–122), after: 111 (105.5–117.5) mm Hg, p=0.29). No significant variations of the microcirculatory parameters were observed after donation. Moreover, the volume collected was not associated with microcirculatory parameters variations. An important inter and intra-individual variability of the microcirculatory parameters was noticed.

Conclusions

No microcirculation impairments were detected after blood donation in healthy dogs. Microcirculatory evaluation with sidestream dark field device showed an important inter and intra-individual variability. Further studies with a larger dog cohort are required to confirm these results.

Disclosures

No disclosures to report.