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Influence of repeated anaesthesia on physiological parameters in male Wistar rats: a telemetric study about isoflurane, ketamine-xylazine and a combination of medetomidine, midazolam and fentanyl.

Albrecht M, Henke J, Tacke S, Markert M, Guth B - BMC Vet. Res. (2014)

Bottom Line: Neither MMF nor ISO showed significant differences in the duration of anaesthetic intervals and BW.The use of ISO in cases where these parameters should be unaffected is therefore not advised.The inability to produce a surgical tolerance, the reduction of sleeping time and BW, as well as the tissue necrosis are significant contraindications for a repeated use of KX.

View Article: PubMed Central - PubMed

Affiliation: Department of Nonclinical Drug Safety, Biological Laboratory Service, Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88397, Biberach, Germany. maike.anika.albrecht@googlemail.com.

ABSTRACT

Background: This study evaluated the influence of repeated anaesthesia using isoflurane (ISO, 2-3 Vol%), ketamine-xylazine (KX, 100 mg·kg(-1) + 5 mg·kg(-1), i.m.) or a combination of medetomidine-midazolam-fentanyl (MMF, 0.15 mg·kg(-1) + 2.0 mg·kg(-1) + 0.005 mg·kg(-1), i.m.) on heart rate (HR), arterial blood pressure (BP), body temperature (BT), duration of anaesthetic intervals and body weight (BW) in Wistar rats. Rats were instrumented with a telemetric system for the measurement of systolic, diastolic and mean arterial pressure (SAP, DAP, MAP), pulse pressure (PP), HR and BT during induction, maintenance and recovery of anaesthesia. Each anaesthesia was performed six times within three weeks. KX was not antagonized, but ISO delivery was terminated 40 minutes after induction and MMF was reversed with atipamezole-flumazenil-naloxone (AFN, 0.75 mg·kg(-1) + 0.2 mg·kg(-1) + 0.12 mg·kg(-1), s.c.).

Results: With repeated anaesthesia, ISO showed a decrease of HR and BP. A significant decrease of PP could be observed with repeated anaesthesia using MMF. HR and BP were not affected by repeated KX anaesthesia, but we noted a reduction of sleeping time and BW. Neither MMF nor ISO showed significant differences in the duration of anaesthetic intervals and BW. With KX we observed tissue necrosis at the injection site and surgical tolerance was not achieved in 25% of the anaesthesias performed.

Conclusion: HR, BP values, BT, duration of anaesthetic intervals and BW were affected differently by repeated anaesthesia performed with ISO, KX or MMF. ISO produced a reproducible anaesthesia, thereby being suitable for repeated use, but with a decrease of HR and BP throughout the six anaesthesias. The use of ISO in cases where these parameters should be unaffected is therefore not advised. The inability to produce a surgical tolerance, the reduction of sleeping time and BW, as well as the tissue necrosis are significant contraindications for a repeated use of KX. Only mild changes of BP were found with repeated MMF anaesthesia, so it seems suitable for serial use, unless the high BP and the low HR during the surgical plane of anaesthesia are undesirable for a special procedure.

No MeSH data available.


Related in: MedlinePlus

Mean duration of KX anaesthesia. Duration of anaesthesia was divided in two different anaesthetic stages. *Statistical significant difference (p value < 0.05) based on the ANOVA for the comparison of the anaesthetic stages of run 2–6 with the anaesthetic stage of run 1.
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Fig2: Mean duration of KX anaesthesia. Duration of anaesthesia was divided in two different anaesthetic stages. *Statistical significant difference (p value < 0.05) based on the ANOVA for the comparison of the anaesthetic stages of run 2–6 with the anaesthetic stage of run 1.

Mentions: The mean durations of the different anaesthetic stages of ISO, KX and MMF are depicted in Figures 1, 2 and 3, respectively. Significant changes were seen for ISO in run 3, when the stage of non-surgical tolerance and the time of surgical tolerance were compared with the same stages of run 1 and in run 5, when the wake-up period was compared with the wake-up period of run 1. With KX significant differences of anaesthetic durations were observed. Induction times of run 2 and 4 were significantly shorter than the induction time of run 1 and times of non-surgical tolerance from run 3–6 were significantly shorter when compared to run 1. For MMF, there were no significant differences observed in the duration of any anaesthetic stage between any of the runs.Figure 1


Influence of repeated anaesthesia on physiological parameters in male Wistar rats: a telemetric study about isoflurane, ketamine-xylazine and a combination of medetomidine, midazolam and fentanyl.

Albrecht M, Henke J, Tacke S, Markert M, Guth B - BMC Vet. Res. (2014)

Mean duration of KX anaesthesia. Duration of anaesthesia was divided in two different anaesthetic stages. *Statistical significant difference (p value < 0.05) based on the ANOVA for the comparison of the anaesthetic stages of run 2–6 with the anaesthetic stage of run 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4301083&req=5

Fig2: Mean duration of KX anaesthesia. Duration of anaesthesia was divided in two different anaesthetic stages. *Statistical significant difference (p value < 0.05) based on the ANOVA for the comparison of the anaesthetic stages of run 2–6 with the anaesthetic stage of run 1.
Mentions: The mean durations of the different anaesthetic stages of ISO, KX and MMF are depicted in Figures 1, 2 and 3, respectively. Significant changes were seen for ISO in run 3, when the stage of non-surgical tolerance and the time of surgical tolerance were compared with the same stages of run 1 and in run 5, when the wake-up period was compared with the wake-up period of run 1. With KX significant differences of anaesthetic durations were observed. Induction times of run 2 and 4 were significantly shorter than the induction time of run 1 and times of non-surgical tolerance from run 3–6 were significantly shorter when compared to run 1. For MMF, there were no significant differences observed in the duration of any anaesthetic stage between any of the runs.Figure 1

Bottom Line: Neither MMF nor ISO showed significant differences in the duration of anaesthetic intervals and BW.The use of ISO in cases where these parameters should be unaffected is therefore not advised.The inability to produce a surgical tolerance, the reduction of sleeping time and BW, as well as the tissue necrosis are significant contraindications for a repeated use of KX.

View Article: PubMed Central - PubMed

Affiliation: Department of Nonclinical Drug Safety, Biological Laboratory Service, Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88397, Biberach, Germany. maike.anika.albrecht@googlemail.com.

ABSTRACT

Background: This study evaluated the influence of repeated anaesthesia using isoflurane (ISO, 2-3 Vol%), ketamine-xylazine (KX, 100 mg·kg(-1) + 5 mg·kg(-1), i.m.) or a combination of medetomidine-midazolam-fentanyl (MMF, 0.15 mg·kg(-1) + 2.0 mg·kg(-1) + 0.005 mg·kg(-1), i.m.) on heart rate (HR), arterial blood pressure (BP), body temperature (BT), duration of anaesthetic intervals and body weight (BW) in Wistar rats. Rats were instrumented with a telemetric system for the measurement of systolic, diastolic and mean arterial pressure (SAP, DAP, MAP), pulse pressure (PP), HR and BT during induction, maintenance and recovery of anaesthesia. Each anaesthesia was performed six times within three weeks. KX was not antagonized, but ISO delivery was terminated 40 minutes after induction and MMF was reversed with atipamezole-flumazenil-naloxone (AFN, 0.75 mg·kg(-1) + 0.2 mg·kg(-1) + 0.12 mg·kg(-1), s.c.).

Results: With repeated anaesthesia, ISO showed a decrease of HR and BP. A significant decrease of PP could be observed with repeated anaesthesia using MMF. HR and BP were not affected by repeated KX anaesthesia, but we noted a reduction of sleeping time and BW. Neither MMF nor ISO showed significant differences in the duration of anaesthetic intervals and BW. With KX we observed tissue necrosis at the injection site and surgical tolerance was not achieved in 25% of the anaesthesias performed.

Conclusion: HR, BP values, BT, duration of anaesthetic intervals and BW were affected differently by repeated anaesthesia performed with ISO, KX or MMF. ISO produced a reproducible anaesthesia, thereby being suitable for repeated use, but with a decrease of HR and BP throughout the six anaesthesias. The use of ISO in cases where these parameters should be unaffected is therefore not advised. The inability to produce a surgical tolerance, the reduction of sleeping time and BW, as well as the tissue necrosis are significant contraindications for a repeated use of KX. Only mild changes of BP were found with repeated MMF anaesthesia, so it seems suitable for serial use, unless the high BP and the low HR during the surgical plane of anaesthesia are undesirable for a special procedure.

No MeSH data available.


Related in: MedlinePlus