Assessment of a portable lactate meter for field use in the white rhinoceros (<i>Ceratotherium simum</i>)

Abstract

Blood lactate is a predictor of mortality in critically ill humans and animals. Handheld lactate meters have the potential to be used in the field to evaluate the condition of severely injured rhinoceroses but have not been compared with laboratory-based methods. Agreement between a handheld lactate meter and a laboratory method was assessed, as was the stability of rhino blood lactate in the anticoagulant sodium fluoride/potassium oxalate (fluoride/oxalate). Blood samples were obtained from 53 white rhinos that had been immobilised for management reasons. Lactate was measured by means of a handheld meter using whole blood in heparin (WBHEP), whole blood in fluoride/oxalate (WBFO) and fluoride/oxalate plasma (PFO). Results were recorded in both blood (BL) and plasma (PL) modes and compared to an established laboratory method for measuring plasma lactate. To assess the stability of lactate over time, blood lactate in fluoride/oxalate was measured on the handheld meter at intervals for up to 91 h. Agreement was best using WBFO in PL mode, with small bias (-0.16), tight 95% limits of agreement (LOA) (-1.46, 1.14) and a Pc (95% CI) of 0.97 (0.92, 0.99). The agreement was improved for all sample types when using the PL mode compared to the blood lactate (BL) mode. Blood lactate was stable in fluoride/oxalate for 91 h, with a mean change from baseline of 0.15 (-0.178, 0.478) mmol/L (mean, 95% CI). The handheld meter was found to be suitable for field use in white rhinos but provided more reliable results with the device in PL mode. Furthermore, rhino blood lactate was found to be stable in fluoride/oxalate for as long as 3 days.

Midazolam Alters Acid-Base Status Less than Azaperone during the Capture and Transport of Southern White Rhinoceroses (Ceratotherium simum simum)

“…Compared to reference values from ground immobilized white rhinoceroses (4.6 mmol/L) [ 35 ] and resting horses (<2 mmol/L) [ 37 ], blood lactate concentrations were markedly elevated at TC. This hyperlactatemia was reflected in a higher AG and negative SIG at TC compared to T0 and during transport (T0–T6) indicating an increase in unmeasured (strong) anions such as lactate [ 37 ].…”

“…Reference intervals for white rhinoceroses, using exactly the same analytical methods and sample types as described here, are only available for selected clinical chemistry measurands [ 31 ]. Other studies report reference values gathered using different methods or samples, so data are not directly comparable, but were still used to assist with interpretation of our findings [ 32 , 33 , 34 , 35 ]. Information from horses was used if rhinoceros reference values were not available (e.g., for Atot) [ 36 , 37 ].…”

Method comparison and generation of plasma biochemistry RIs for the White rhinoceros on a point‐of‐care and wet chemistry analyzer

“…Various conservation strategies used to combat poaching concentrate on preventing animals from being harmed in the first place, but some victims of poaching do survive the initial trauma and can be successfully treated . Analysis of blood samples during first assessment and subsequent management are important in clinical decision‐making for these animals …”

Conserving wildlife in a changing world: Understanding capture myopathy—a malignant outcome of stress during capture and translocation

“…It is well known that immobilized large animals, such as rhinoceros, run the risk of rhabdomyolysis due to reduced blood flow and hypoxaemia (i.e. ischaemia), especially in their limbs, during recumbency (Meyer et al , 2015; Cole et al , 2017). Sadly, the incidence of rhinoceros that have been chemically immobilized by poachers and not killed has increased over the years, particularly due to this type of poaching method being more discreet compared to the noise of gunshots.…”

“…Sadly, the incidence of rhinoceros that have been chemically immobilized by poachers and not killed has increased over the years, particularly due to this type of poaching method being more discreet compared to the noise of gunshots. These animals are often deserted without reversing the immobilizing drugs (most often opioid anaesthetic drugs) and may remain immobilized for hours before they are found or when the anaesthesia wears off (Meyer et al , 2015; Cole et al , 2017). The consequence is usually extensive myopathy, characterized by rhabdomyolysis and myoglobin-induced kidney injury, which carries a poor prognosis for many of these animals (Meyer et al , 2015).…”