The anesthesiologist's guide to swine trauma physiology research: a report of two decades of experience from the experimental traumatology laboratory

Abstract

Purpose: Swine are one of the major animal species used in translational research, with unique advantages given the similar anatomic and physiologic characteristics as man, but the investigator needs to be familiar with important differences. This article targets clinical anesthesiologists who are proficient in human monitoring. We summarize our experience during the last two decades, with the aim to facilitate for clinical and non-clinical researchers to improve in porcine research.

Methods: This was a retrospective review of 337 swine with a mean (SD) weight 60 (4.2) kg at the Experimental Traumatology laboratory at Södersjukhuset (Stockholm south general hospital) between 2003 and 2023, including laboratory parameters and six CT-angiography examinations.

Results: Swine may be ventilated through the snout using a size 2 neonatal mask. Intubate using a 35 cm miller laryngoscope and an intubating introducer. Swine are prone to alveolar atelectasis and often require alveolar recruitment. Insert PA-catheters through a cut-down technique in the internal jugular vein, and catheters in arteries and veins using combined cut-down and Seldinger techniques. Cardiopulmonary resuscitation is possible and lateral chest compressions are most effective. Swine are prone to lethal ventricular arrhythmias, which may be reversed by defibrillation. Most vital parameters are similar to man, with the exception of a higher core temperature, higher buffer bases and increased coagulation. Anesthesia methods are similar to man, but swine require five times the dose of ketamine.

Conclusion: Swine share anatomical and physiological features with man, which allows for seamless utilization of clinical monitoring equipment, medication, and physiological considerations.

Keywords: Anesthesiology; Experimental traumatology; Porcine research; Swine physiology research; Trauma.

Fig. 1

3D renderings of computed tomography showing (A) the configuration of the neck and thoracic cage. (B) femoral artery exiting the pelvis and point of access in the hind leg

Fig. 2

3D renderings of computed tomography showing vascular and ventilatory accesses. (A) The PA-catheter is placed on the right side of the trachea by cut-down technique. Tracheostomy (or intubation) in the trachea. An arterial line may be placed in the left internal carotid, if not placed in the foreleg

Fig. 3

Airway management. (A) Ventilation is easily achieved using a size 2 neonatal mask over the nostrils and keeping the mouth shut. (B) A custom-made 35 cm miller-type laryngoscope and an intubating introducer (bougie catheter) are used for intubation. (C) Intubation is performed by visualizing the larynx with the miller laryngoscope and placing the bougie catheter in the trachea, on which the tube is passed. An assistant is holding the lower jaw (D) The tube is inserted all the way to the corner of the mouth and the cuff is inflated

Fig. 4

Vascular access. (A) The easiest venous access is obtained in the ear. (B) To keep the access open, place a rolled-up gauze in the ear to prevent the ear from folding. (C) Needle puncture for Seldinger technique access of the femoral artery through a skin incision perpendicular to the ultrasound probe. (D) Out of plane ultrasonogram of the femoral artery and femoral vein (scale in centimeters). (E) arterial needle is best placed in the foreleg, by first making a small incision and protruding the needle using ultrasound. (F) Keep the foreleg extended by traction to keep the arterial line open