Injection anaesthesia with fentanyl–midazolam–medetomidine in adult female mice: importance of antagonization and perioperative care

Abstract

Injection anaesthesia is commonly used in laboratory mice; however, a disadvantage is that post-anaesthesia recovery phases are long. Here, we investigated the potential for shortening the recovery phase after injection anaesthesia with fentanyl-midazolam-medetomidine by antagonization with naloxone-flumazenil-atipamezole. In order to monitor side-effects, the depth of anaesthesia, heart rate (HR), core body temperature (BT) and concentration of blood gases, as well as reflex responses, were assessed during a 50 min anaesthesia. Mice were allowed to recover from the anaesthesia in their home cages either with or without antagonization, while HR, core BT and spontaneous home cage behaviours were recorded for 24 h. Mice lost righting reflex at 330 ± 47 s after intraperitoneal injection of fentanylmidazolam-medetomidine. During anaesthesia, HR averaged 225 ± 23 beats/min, respiratory rate and core BT reached steady state at 131 ± 15 breaths/min and 34.3 ± 0.25℃, respectively. Positive pedal withdrawal reflex, movement triggered by tail pinch and by toe pinch, still occurred in 25%, 31.2% and 100% of animals, respectively. Arterial blood gas analysis revealed acidosis, hypoxia, hypercapnia and a marked increase in glucose concentration. After anaesthesia reversal by injection with naloxoneflumazenil-atipamezole, animals regained consciousness after 110 ± 18 s and swiftly returned to physiological baseline values, yet they displayed diminished levels of locomotion and disrupted circadian rhythm. Without antagonization, mice showed marked hypothermia (22 ± 1.9℃) and bradycardia (119 ± 69 beats/min) for several hours. Fentanyl-midazolam-medetomidine provided reliable anaesthesia in mice with reasonable intra-anaesthetic side-effects. Post-anaesthetic period and related adverse effects were both reduced substantially by antagonization with naloxone-flumazenil-atipamezole. AbstractInjection anaesthesia is used commonly in laboratory mice; however, long-lasting post-anaesthesia

Sevoflurane preconditioning protects from posttransplant injury in mouse lung transplantation

“…Another limitation of this study was that the cardio-dynamic parameters between volatile anesthetics and injection anesthetics of fentanyl, midazolam, and medetomidine used for controls. 31,32 Although the intravenous narcosis is widely used in the clinical setting and qualifies well for this control group (equivalent to i.p. narcosis), it limits the comparability to a clinical setting due to interference with inflammatory parameters analyzed.…”

Anesthetics fragment hippocampal network activity, alter spine dynamics and affect memory consolidation

“…In contrast to Keta/Xyl-anesthesia, Isoflurane-and MMF-anesthesia can be efficiently 141 antagonized by removing the face mask or injecting a wake-up cocktail (Flumazenil,142 Atipamezol and Buprenorphine, FAB) (Albrecht et al, 2014;Fleischmann et al, 2016), 143…”

Blutgasanalyse beim Kaninchen während einer vollständig antagonisierbaren Anästhesie unter besonderer Berücksichtigung des Sauerstoffmanagements

“…Da nach AntagonisierungderanalgetischeEffektaufgehobenwird,isteine postoperative Analgesie, z. B. mit einem nicht steroidalen Antiphlogistikum oder Buprenorphin, stets zu empfehlen [14].…”

“…Dieses Gebot lässt sich auch auf Kleinsäuger und Kaninchen übertragen und ist dort umso wichtiger, da die Gesamtrate an Todesfällen durch eine Allgemeinanästhesie oder Sedation mit durchschnittlich 1,37 % wesentlich höher liegt als bei Hund (0,17 %) oder Katze (0,24 %) [6]. Neben der Inhalationsanästhesie haben sich für die Narkose von Kleinsäugern verschiedene Formen der Injektionsanästhesie etabliert [14] [18] [19] [21] [27] [29] [35]. Im Zusammenhang mit Inhalations-und Injektionsanästhesien sind für das Kaninchen zudem diverse Techniken der Intubation beschrieben; seit einigen Jahren steht auch eine spezielle Larynxmaske zur Verfügung [33].…”