continuous-telemetric-utero-tracheal-pressure-measurements-fetal

Continuous Telemetric <em>In Utero</em> Tracheal Pressure Measurements in Fetal Lambs

Normal in utero lung development and growth rely upon the expansion of airspaces and the controlled efflux of lung liquid into the amniotic space. Infants ...

The University of Western Australia

Fifty-four pigs ( Sus scrofa, Large White cross) from a commercial pig farm were anaesthetised over a six-year period from October 2011. The procedural stages included initial instrumentation for intra-operative monitoring, laparoscopic nephrectomy, preparation of the kidney graft, orthotopic auto-transplantation by either a laparoscopic approach or an open surgical approach, and ligation of the contralateral ureter. During the evolution and establishment of this pig model multiple refinements were introduced: (1) a heat pad was changed to a circulating warm air blanket; (2) routine administration of anticholinesterase and antimuscarinic drugs for reversal of neuromuscular blockade; (3) a technique for urethral catheterisation was developed; (4) ultrasound guidance for placement of a central venous line was learned; (5) intravenous infusions of morphine and ketamine were instituted for a more stable and balanced anaesthetic protocol; and (6) post-operative monitoring was performed by two technical staff for at least the first six hours after extubation of the trachea. The combination of refinements to the anaesthesia protocol for laparoscopic orthotopic kidney auto-transplantation over the first 54 pigs has translated to improved outcomes. This conclusion is entirely subjective as accurate measurement of the impact of each refinement is impossible. Nevertheless, refinement is a continuous process and should be applied to the entire range of procedures involved in animal use for scientific purposes.

Multiple refinements to the anaesthetic protocol for laparoscopic orthotopic kidney auto-transplantation in a pig model.

The aim of this study was to document the packed cell volume (PCV), haemoglobin concentration and total protein concentration of maternal blood before, during and after anaesthesia. Six singleton Merino-cross pregnant ewes at 116-117 days of gestation were premedicated with intramuscular acepromazine (0.02 mg/kg) and buprenorphine (0.01 mg/kg), and anaesthesia was induced with intravenous midazolam and ketamine. Anaesthesia was maintained with isoflurane in 100% oxygen. Serial blood samples were collected the day before anaesthesia (baseline), immediately prior to induction of anaesthesia (pre-op), at the end of the procedure (intra-op) and the following day (post-op). There was a significant change in the PCV during the study ( = 0.003) with an initial decrease of 12.5% from the baseline (0.36 (0.36-0.4) to 0.315 (0.29-0.34),  = 0.044), a further intraoperative decrease of 41.7% from the baseline (0.21 (0.195-0.245),  = 0.002) and an increase the day afterwards (0.3 (0.285-0.35),  > 0.99 compared with baseline). The haemoglobin concentration also changed ( < 0.0001) (baseline: 114 (111.8-123); pre-op: 97 (77.25-104.5), 14.9% decrease,  = 0.022; intra-op: 70 (61.5-83.25), 38.5% decrease,  = 0.0009; post-op: 101.5 (96.25-114) g/L,  > 0.99). Likewise the change in total protein during the study was significant ( = 0.0003) and decreased from the baseline [70 (67.25-70.75) g/L] prior to anaesthesia (61 (58.25-64.5) g/L, 12.9% decrease,  = 0.0437) and further during anaesthesia (55.5 (53.75-63.25) g/L, 20.7% decrease,  = 0.0021) with an increase [63 (61.25-67) g/L,  > 0.99] on the first post-op day. In conclusion, intraoperative anaemia and hypoproteinaemia occurred in this study. These alterations are attributed to a combination of the side effects of acepromazine and haemodilution.

Anaemia and Hypoproteinaemia in Pregnant Sheep during Anaesthesia.

During multiple organ procurement, blood vessels are routinely retrieved and stored in University of Wisconsin solution and then discarded after two weeks, if not used at organ transplantation owing to lack of a method for long-term preservation. Therefore, the aim of this study is to investigate a method for long-term preservation of vascular allografts in ethanol.

Investigation of a method for long-term preservation of the vascular allograft.

Fatty streaks initiating the formation of atheromatous plaque appear in the tunica intima. The tunica media is not known to be a nidus for lipid accumulation initiating atherogenesis. We assessed changes to the tunica media in response to a micro-injury produced in the pig aorta. In addition, we assessed human carotid endarterectomy plaques for indication of atheroma initiation in the tunica media.

Article	Year
Multiple refinements to the anaesthetic protocol for laparoscopic orthotopic kidney auto-transplantation in a pig model. Laboratory animals\| PubMed ID: 30348047	2019
Anaemia and Hypoproteinaemia in Pregnant Sheep during Anaesthesia. Animals : an open access journal from MDPI\| PubMed ID: 30978963	2019
Investigation of a method for long-term preservation of the vascular allograft. Vascular\| PubMed ID: 33966508	2022
Injury to the tunica media initiates atherogenesis in the presence of hyperlipidemia. Frontiers in cardiovascular medicine\| PubMed ID: 37063951	2023

Helen Kershaw

Biography

JoVE Journal Publications

Other Publications