Midazolam sedates Passeriformes for field sampling but affects multiple venous blood analytes

Abstract

Feasibility and effect of midazolam administration on blood analytes and for sedation of Passeriformes being collected in a larger study of genetic biodiversity was assessed. Midazolam (5.6±2.7 mg/kg) was administered intranasally prior to sampling, euthanasia, and specimen preparation of 104 passerine birds. Each bird was assessed for sedation score and then multiple analytes were determined from jugular blood samples using the i-STAT® point of care analyzer at “bird side”. Most birds were acceptably sedated, sedation became more pronounced as midazolam dose increased, and only a single bird died. Electrolyte concentrations and venous blood gas analytes were affected by midazolam administration while blood pH, packed cell volume, hemoglobin, and calculated hematocrit were not. Intranasal midazolam gives adequate sedation and is safe for short-term use in free-living Passeriformes. Based on venous blood analyte data, sedation of Passeriformes prior to handling appears to reduce stress but also produces venous blood gas differences consistent with hypoventilation relative to birds which were not given midazolam. Further study is recommended to investigate midazolam’s continued use in free-living avian species. Studies should include safety, reversal and recovery, effect upon additional endogenous analytes, and compatibility with studies of ecology and toxicology associated with pollution or other environmental degradation in Passeriformes.

Glucose Concentrations in Closely Related Titmice (Baeolophus) Species Linked to Regional Habitat Differences Across an Avian Hybrid Zone

“…A small sample size from the western population and inherent analyte variability likely prevented statistical distinctions between the western and hybrid zone populations (Table 3). The difference in glucose east and west of the BE was also observed in our related studies of multiple Texas passerine species [29,30]. Although pO 2 and sO 2 also differed between titmice east and west of the BE, differences resulted from age, sex, and/or midazolam administration.…”

“…Since this hybrid zone occurs at a strong ecotone, we aim to investigate which blood gases and electrolytes differ between Tufted and Black-crested Titmice and assess if the differences are linked to climate and/or habitat. In a previous study of a suite of passerines, including titmice, we observed differences in venous blood analytes between individuals sampled east of the BE, relative to those sampled west of the BE [29,30]. We hypothesize that, between species, differences in blood analyte concentrations will be strongly correlated with habitat or climatic differences associated with the different ecoregions east and west of the BE.…”

“…Injection USP Hospira, Inc.) intra-nasally prior to blood collection for sedation [29]. Midazolam is a safe and effective sedative of wild birds [31 -33].…”

“…Midazolam is a safe and effective sedative of wild birds [31 -33]. Clinical effects of sedation were observed and recorded on a sedation scale [29]. Following rest or sedation plus rest, we obtained blood samples (200-500 µL) via jugular venipuncture and immediately transferred to lithium heparin Microtainer tubes (Sarstedt Inc., USA) for anticoagulation prior to analysis.…”

“…Samples were analyzed in the field using an i-STAT 1 system (Abbott Laboratories, USA), following standard field protocols [30]. Cartridges that evaluated blood gases were used first to minimize the change in analytes based on time-lapse from sampling [29]. Remaining cartridges were analyzed within 5 min of blood collection.…”