Vital signs monitoring during injectable and inhalant anesthesia in mice

Abstract

Selecting the appropriate anesthetic protocol for the individual animal is an essential part of laboratory animal experimentation. The present study compared the characteristics of four anesthetic protocols in mice, focusing on the vital signs. Thirty-two male ddY mice were divided into four groups and administered anesthesia as follows: pentobarbital sodium monoanaesthesia; ketamine and xylazine combined (K/X); medetomidine, midazolam, and butorphanol combined (M/M/B); and isoflurane. In each group, rectal temperature, heart rate, respiratory rate, and O2 saturation (SPO2) were measured, and the changes over time and instability in these signs were compared. The anesthetic depth was also evaluated in each mouse, and the percentage of mice achieving surgical anesthesia was calculated. K/X anesthesia caused remarkable bradycardia, while the respiratory rate and SPO2 were higher than with the others, suggesting a relatively strong cardiac influence and less respiratory depression. The M/M/B group showed a relatively lower heart rate and SPO2, but these abnormalities were rapidly reversed by atipamezole administration. The pentobarbital group showed a lower SPO2, and 62.5% of mice did not reach a surgical anesthetic depth. The isoflurane group showed a marked decrease in respiratory rate compared with the injectable anesthetic groups. However, it had the most stable SPO2 among the groups, suggesting a higher tidal volume. The isoflurane group also showed the highest heart rate during anesthesia. In conclusion, the present study showed the cardiorespiratory characteristics of various anesthetic protocols, providing basic information for selecting an appropriate anesthetic for individual animals during experimentation.

Somatostatin Reduces the Acute Lung Injury of Mice via Increasing the Affinity of Glucocorticoid Receptor

“…Although published documents reported that the effects of anesthesia on murine models of lung injury should be considered, the dosage (50 mg/ kg) we used is a relatively low dose in mice [33] and no pentobarbital-induced death was observed in the present study. The O 2 saturation (SPO 2 ) at this dose is approximately 90% at 35-40 min after anesthesia [34], which would not have a significant effect on ALI.…”

Cardiac Radionuclide Imaging in Rodents: A Review of Methods, Results, and Factors at Play

“…The most severe adverse effect of isoflurane is depression of respiratory rate, superior to that induced by ketamine/xylazine and pentobarbital; however, tidal volume seems to be better maintained during isoflurane anesthesia, accounting for relatively higher peripheral capillary oxygen saturation (SPO 2 ) compared with pentobarbital (78). …”

“…Such effect was not observed after 20 h of fasting, suggesting that it might be related to transient fluctuations of glucose levels (64). Respiratory depression with reduction of SPO 2 is of most concern after administration of pentobarbital (78). …”

“…Animal body temperature may decrease by several degrees with anesthesia; therefore, it needs to be strictly monitored during the experiments (78). In fact, non-warmed animals show a high uptake by brown fat, skeletal muscle and Harderian glands, which might interfere with the quality of images and their reproducibility.…”

Heart-rate sensitive optical coherence angiography for measuring vascular changes due to posttraumatic brain injury in mice

“…In sedated mouse models, the heart rate is expected in the range 5 < f h < 10 Hz (300 to 600 bpm). 24,25 Thus, the minimum sampling rate required is f min ¼ 20 Hz. In spectral-domain OCT, each axial scan (A-scan) is acquired by a single spectrometer exposure at a rate f Ascan .…”