Effect of the number of incisions and use of local anesthesia on the physiological indicators of surgically-castrated piglets

Abstract

The objective of this study was to determine the effect of local anesthesia and the number of incisions performed on the physiological blood profile of piglets after surgical castration. A total of 60 male piglets were divided into five groups of 12 each, based on the surgical method employed and the use, or not, of local anesthesia, as follows: surgical castration using one horizontal incision in both testicles with (C1+L) and without (C1) local anesthesia; surgical castration using two vertical scrotal incisions with and without local anesthesia (C2+L and C2); and control piglets which were removed from their pens and held head-down by their hind limbs for approximately 90 s to simulate castration (SIM). Reference blood samples were drawn 24 h before castration (RV), immediately after surgery or simulated castration (PC), and at 24 and 48 h post-castration, to determine physiological profiles including; pH, hematocrit, glucose, electrolytes, lactate, pCO2 (mmHg), SO2 (mmHg), and bicarbonate. Results showed increases in lactate and hematocrit immediately after surgical or simulated castration with decreases in pH, HCO3− and base excess (BE). Surgical castration produced marked alterations of the physiological profile, detected by reduced pH and HCO3, higher lactate levels and BE alterations. These changes indicated metabolic acidosis that was greater in the piglets castrated surgically with one horizontal incision than in those castrated with two vertical incisions. More research is needed on the use of lidocaine during surgical castration, as it showed no effect on physiological profile in this study, but did alter hematocrit values.

Local Anesthesia in Piglets Undergoing Castration—A Comparative Study to Investigate the Analgesic Effects of Four Local Anesthetics Based on Defensive Behavior and Side Effects

“…Several studies have already been conducted on local anesthesia as an alternative to piglet castration without anesthesia but they differed in study designs, local anesthetics used and yielded heterogeneous results [ 8 , 9 , 10 , 11 , 12 , 13 ]. This second part of a comprehensive study examined the four local anesthetics, procaine, lidocaine, bupivacaine and mepivacaine, in conscious piglets during castration in the first week of life.…”

“…The possibility of castration with local anesthetics is currently not permitted in Germany, because the evidence of the efficacy of this method is still controversially discussed. Kluivers-Poodt et al [ 8 ], Hansson et al [ 9 ] and Leidig et al [ 10 ] concluded that the use of local anesthetics reduces pain responses during castration, whereas Perez-Pedraza et al [ 11 ] did not show any effect. Bonastre et al [ 12 ] as well as Rauh et al [ 13 ] indicated that local anesthetics lead to a reduction in pain-related responses, without eliminating the pain.…”

“…Lidocaine is currently used for piglet castration in Norway, Sweden and Italy [ 5 ]. The effects of procaine and lidocaine in piglets undergoing castration have been investigated in various studies [ 8 , 9 , 10 , 11 , 12 , 13 , 15 ] but showed contradictory results. Furthermore, Bonastre et al [ 12 ] investigated the effect of the combination of lidocaine and bupivacaine.…”

Local anesthesia in piglets undergoing castration—A comparative study to investigate the analgesic effects of four local anesthetics on the basis of acute physiological responses and limb movements

“…Whereas different concentrations and application techniques of lidocaine [2,3,8,9,[15][16][17][18][19]21,39,41,[47][48][49][50][51][52][53][54][55][56] and procaine [9,17,41,42,[57][58][59] have been excessively studied in the context of piglet castration, bupivacaine was analyzed only in combination with lidocaine by Bonastre et al [60]. To the best of our knowledge, mepivacaine, an approved drug in several European countries for intraarticular and epidural injections in horses, has never been used in studies examining piglet castration.…”

Optimal methods of documenting analgesic efficacy in neonatal piglets undergoing castration

“…The more consistent results are seen with the use of NSAIDs. Compared with piglets castrated without analgesic treatment, significantly reduced plasma cortisol and / or ACTH levels have been documented in NSAID-treated piglets at 30 mins [10,14,17,53] 60 min [13,23,24], or up to 4 hrs post-procedure [11,13,23]. Others however, have reported no significant (p<0.05) effect of NSAIDs administered prior to [12,15,18] or at the time of the procedure [20,25], on cortisol and/or ACTH, nor acute phase reactants, Hp, SAA and / or CRP [10,19,24].…”