Introduction
Several techniques for anesthesia of the paralumbar fossa, including proximal paravertebral nerve block, distal paravertebral nerve block, inverted L-block (ILB), and infusion of the incision or line block, can be achieved for laparotomy in adult cows.1 These anesthetic techniques are commonly used in laparotomy, such as omentopexy, abomasopexy, rumenotomy, and cesarean section. To minimize surgical pain, sedatives, tranquilizers, narcotics, anesthetics, and the strategic use of NSAIDs are recommended.2
In the castration of calves, preoperative administration of NSAIDs and local anesthesia significantly decreases the peak serum cortisol concentration after the procedure.3 In the dehorning of calves, the use of local anesthetics, NSAIDs, and sedation has mitigated acute pain following dehorning.4,5 Cortisol concentration is an important index in pain management,3,6 but few studies have measured it for evaluating presurgical treatment, including anesthesia and preoperative analgesia, for laparotomy in adult cows.
This study aimed to evaluate the analgesic efficacy of ILB with preoperative flunixin meglumine and dorsolumbar epidural anesthesia compared to standard ILB in cows undergoing omentopexy for displaced abomasum (DA). Blood samples were collected from cows to evaluate operative stress by measuring the serum cortisol concentrations pre- and postoperatively in the 3 groups.
Materials and Methods
The study protocol was approved by the Animal Research Committee of Rakuno Gakuen University (approval No. VH18C3). Cows diagnosed with left or right DA by farm veterinarians were transported via livestock cars from the farms to the Rakuno Gakuen University Animal Medical Center (AMC). The distance from each farm to the AMC was < 35 km, and the travel time was 5 to 40 minutes. A total of 40 female Holstein dairy cows (body weight, 622.6 ± 74.6 kg; body condition score, 2.89 ± 0.24; and day in milk, 63.4 [range, 2 to 292]) were included in this study. Cows with abomasal volvulus and abomasal ulcers at the preoperative clinical examination or during surgery were excluded from the analysis. The cows were divided by block randomization into the following 3 groups: the ILB group (n = 13), ILB with preoperative IV injection of flunixin meglumine as NSAID (ILB-F) group (13), and dorsolumbar epidural anesthesia (EPI) group (14).
ILB anesthesia was administered as previously described.1 An 18-gauge, 1.5-inch needle was used to inject up to 50 mL of 2% lidocaine in multiple small injection sites into the tissues bordering the dorsocaudal aspect of the thirteenth rib and ventrolateral aspect of the transverse processes of the lumbar vertebrae. Dorsolumbar epidural anesthesia was induced as described previously.7,8 A 16-gauge disposable epidural needle (Hakko Medical Inc), which was 12 mm in length, was slowly inserted into the T13–L1 or L1–2 intervertebral space using the dorsal midline approach after skin hair clipping (Figure 1). Entrance into the epidural space was identified using the hanging drop technique. For the EPI group, the anesthetic consisted of 0.8 mL of 2% xylazine and 4 mL of 2% lidocaine. The needle bevel was directed to the right laterocranial side, and the anesthetic was administered very slowly. The needle was removed after administration.
EPI and ILB were administered 20 minutes before surgery, and the ILB-F group was injected IV with 2 mg/kg flunixin meglumine (Flunixin-chu) 15 minutes preoperatively. The mean time from arrival at the AMC to the start of surgery was 92.6 minutes. Either of the 2 experienced surgeons performed the standing right paralumbar fossa omentopexy,9,10 and the mean ± SD operative time was 50.9 ± 15.5 minutes. Abnormal intraoperative behavior data were documented in the medical chart. Postoperatively, the cows were admitted to the AMC’s single housing pen, which was 3.3 X 3.8 m so that 1 adult cow could walk free, for 18 to 24 hours before being returned to their respective farms.
Rectal temperature, pulse rate, and respiratory rate were checked preoperatively and 0 (immediately), 3, 17, and 48 hours postoperatively. Blood samples (10 or 20 mL) were collected from the jugular or caudal tail vein preoperatively and 0, 3, 17, and 48 hours postoperatively in EDTA and plain tubes. The samples collected in EDTA tubes were immediately subjected to CBC analysis using a multiparameter automated hematology analyzer for animals (pocH-100iV Diff; Sysmex Corp). Preoperative sera were measured using a clinical chemistry analyzer (Fuji Dry Chem NX500; Fujifilm) for glucose, sodium, potassium, chloride, calcium, phosphorus, magnesium, total bilirubin, glutamate-oxaloacetate transaminase, GGT, total protein, and albumin by the Daiichi Kishimoto Clinical Laboratories for nonesterified fatty acids and β-hydroxybutyric acid (Supplementary Table S1). All serum samples were frozen at −30 °C prior to the cortisol assay.
Serum cortisol was analyzed using a commercially available cortisol kit (Cortisol Enzyme Immunoassay Kit; Arbor Assays Inc) according to the manufacturer’s protocols. The serum cortisol concentrations were determined from the concentration versus absorbance relationship of the standard cortisol concentration (13.8 to 882.9 nmol/L). Assay samples below this threshold were denoted as 13.8 nmol/L. The intra- and interassay coefficients of variation were 5.7% and 6.9%, respectively.
The Kruskal-Wallis test was employed to compare the preoperative blood samples among the 3 groups. Rectal temperature, pulse rate, and respiratory rate were compared with time for each preoperative treatment at 0 hours, preoperatively, and 3, 17, and 48 hours postoperatively by the Friedman test followed by the corrected Bonferroni method. The Kruskal-Wallis test was employed to compare among the 3 groups. To evaluate whether the cortisol concentrations were variable with time, the variables were evaluated using a mixed-model ANOVA for repeated measures. The Bonferroni method was used as a post hoc test for cortisol concentrations at 0, 3, 17, and 48 hours postoperatively, which were significantly variable from the preoperative values. The area under the curve (AUC) with respect to the ground was examined to determine the magnitude and severity of the cortisol response to treatment over the 48-hour period postoperatively.11 AUC was calculated using the linear trapezoidal method for the following time intervals: preoperatively to 48 hours postoperatively, preoperatively to 0 hours postoperatively, preoperatively to 3 hours postoperatively, preoperatively to 17 hours postoperatively, and 0 to 3 hours postoperatively. The time from preoperatively to 0 hours was set to 1 hour to take the elapsed time into account. Statistical analysis was conducted using SPSS (version 27; IBM Corp), and a P value < .05 was considered statistically significant. Data are expressed as the mean and lower and upper limits of 95% CIs.
Results
All 40 cows underwent standing right paralumbar fossa omentopexy and did not have abomasal volvulus or ulcers; thus, they were all included in the study. None of the blood variables exhibited a significant difference preoperatively among the 3 groups.
Rectal temperatures changed over time in the ILB-F and EPI groups (both, P = .001; Figure 2). At 17 hours postoperatively in the ILB-F and EPI groups, they were lower than at 0 hours postoperatively (ILB-F, P = .032; EPI, P = .008). None of the pulse rates exhibited a significant difference compared to 0 hours postoperatively. Respiratory rates changed over time in all groups (ILB, P = .001; ILB-F, P = .014; ILB, P = .029; Figure 3). In the ILB group, the variables at 3 and 48 hours were lower than the variable at 0 hours postoperatively (3 hours, P = .015; 48 hours, P = .008). The rectal temperature, pulse rate, and respiratory rate did not exhibit significant differences at any points among the 3 groups.
The serum cortisol concentrations (nmol/L) changed over time in all groups (ILB, P = .001; ILB-F and EPI, P < .001; Figure 4). The mean preoperative cortisol concentration in the ILB group was 108.7 (66.7 to 150.7). At 0 hours postoperatively, it was the highest at 118.6 (64.2 to 172.9; P = 1.000) and at 3 hours, 80.1 (38.5 to 121.8; P = .388). However, at 17 and 48 hours, the mean cortisol concentrations decreased to 60.7 (35.6 to 85.8; P = .026) and 54.3 (40.0 to 68.8; P = .009), respectively. In the ILB-F group, the mean preoperative cortisol concentration was the highest at 150.7 (116.4 to 185.0) and then decreased to 93.2 (56.0 to 130.4; P = .001) at 0 hours, 52.7 (35.1 to 70.4; P < .001) at 3 hours, 46.1 (30.7 to 61.5; P < .001) at 17 hours, and 50.3 (32.6 to 68.0; P < .001) at 48 hours postoperatively. In the EPI group, the mean preoperative cortisol concentration was the highest at 139.8 (93.4 to 186.3), and it decreased to 83.4 (63.1 to 103.7; P < .001) at 0 hours, 63.8 (51.3 to 76.3; P < .001) at 3 hours, 54.0 (39.0 to 69.0; P < .001) at 17 hours, and 58.7 (37.5 to 79.9; P < .001) at 48 hours postoperatively.
None of the AUCs in all classifications exhibited a significant difference among the 3 groups (Table 1).
Results of area under the curve (AUC; nmol/L per mean ± standard error of the mean [SEM]) for the serum cortisol of the 3 groups: inverted L-block anesthesia group (ILB; n = 13); ILB with preoperative IV injection of flunixin group (ILB-F; 13); and dorsolumbar epidural anesthesia group (EPI; 14).
AUC | ILB | ILB-F | EPI | P value | |||
---|---|---|---|---|---|---|---|
Mean | SEM | Mean | SEM | Mean | SEM | ||
AUCpre-48h | 3,180.1 | 511.4 | 2,526.9 | 253.7 | 2,904.4 | 321.1 | .483 |
AUCpre-0h | 113.6 | 19.3 | 122.0 | 14.5 | 111.6 | 14.7 | .893 |
AUCpre-3h | 411.7 | 82.7 | 340.9 | 47.2 | 332.5 | 30.1 | .562 |
AUCpre-17h | 1397.5 | 273.2 | 1,033.0 | 121.7 | 1,157.3 | 100.9 | .361 |
AUC0h-3h | 298.1 | 65.2 | 219.0 | 33.3 | 220.9 | 17.0 | .339 |
No significant differences were observed between the 3 groups.
AUCpre–48h = AUC from preoperatively to 48 hours postoperatively. AUCpre–0h = AUC from preoperatively to 0 hours postoperatively. AUCpre–3h = AUC from preoperatively to 3 hours postoperatively. AUCpre–17h = AUC from preoperatively to 17 hours postoperatively. AUC0h–3h = AUC from 0 to 3 hours postoperatively.
Discussion
In this study, 40 Holstein dairy cows diagnosed with left or right DA were administered the following presurgical treatments: ILB, a simple local anesthesia; ILB-F, ILB with preoperative IV injection of NSAID; and EPI, a popular anesthesia for laparotomy of adult cows in Japan. Their serum cortisol concentrations were determined before and after performing standing right paralumbar fossa omentopexy. The results indicated significant decreases in the postoperative cortisol concentrations in all groups compared with the preoperative cortisol concentrations. Concretely, the cortisol concentrations of the ILB-F and EPI groups decreased from immediately (0 hours) to 48 hours postoperatively, whereas that of the ILB group decreased from 17 to 48 hours postoperatively. In addition, ILB-F and EPI decreased in rectal temperature at 17 hours, and ILB decreased in respiratory rate at 3 and 48 hours compared to immediately postoperatively. However, none of the rectal temperatures, pulse rates, and respiratory rates exhibited a significant difference among the 3 groups, nor the AUC for the cortisol concentration. In cattle, it was reported that dairy cows subjected to stress had increased cortisol concentrations.12 Cortisol concentration measurement was found to be a useful tool for pain and stress assessment.13,14 Surgeries cause varying degrees of pain or distress, which leads to distress in cattle.15 To summarize the results of this study, ILB-F and EPI showed equal anesthetic effects compared to ILB. However, the postoperative cortisol concentration in the ILB-F and EPI rapidly decreased compared to preoperative cortisol concentrations; thus, it was suggested that the surgical stresses were rapidly ameliorated. Regarding the reason for the delayed decrease in postoperative cortisol concentration in the ILB group, it was considered that respiratory rate at immediately after surgery in the ILB group was high, which might have been due to the severe pain associated with surgery. In previous studies on laparotomy in cattle, the plasma cortisol concentration was not reported, and studies on arthroscopic surgery or laparotomy in horses reported that the plasma cortisol concentration against baseline increased intraoperatively to 3 to 4 hours postoperatively and decreased at 6 to 24 hours postoperatively.16–18 Furthermore, because all 40 cows in this study were transported via livestock cars to the AMC for 40 minutes, they were considered to have already been stressed preoperatively due to not only the disease but also transportation. Some papers have reported that cortisol after a short trip (< 2 hours) in cattle shows a significant increase compared with pretrip levels,19 and other papers have reported that there is no significant difference between pre- and post-trip cortisol levels.20,21 The ILB-F and EPI groups had the highest preoperative mean cortisol concentrations throughout the observation period. It was difficult to rule out transportation as the reason for the high preoperative cortisol concentration; thus, we considered it one of the limitations of this study. However, all cows were transported back to their respective farms between 18 and 24 hours, and no increase in cortisol concentration was observed after 48 hours. Therefore, it was considered that the preoperative cortisol concentration strongly reflected the stress related to DA, whereas the postoperative cortisol concentration reflected the removal of the stress related to DA and postsurgical stress.
The effect of local analgesia with lidocaine starts within 15 minutes for both ILB and EPI and lasts for 60 to 90 minutes.7 No cow received additional anesthetics because almost all surgeries were performed within the effective period of the anesthetic. In the postoperative period, many cows, regardless of the group, exhibited swelling and heat at the surgical site, but the level of these symptoms was considered to be within the normal wound healing response. Although 1 cow from the ILB-F group had an infected surgical wound that required treatment later, no other problems were observed in the cows. The advantages of ILB are that it is simple to perform and does not induce gait disturbance.22 Its disadvantages include incomplete analgesia, muscle relaxation of the deeper layers of the abdominal wall, possible toxicity, and increased cost, as the technique requires larger doses.8 Lidocaine solution was used for the ILB and ILB-F groups in this study, and all 13 cows in the ILB group demonstrated intraoperative kicking and violent movement to varying degrees. Such behaviors are symptoms reflecting pain,15 which showed that the highest cortisol at 0 hours postoperatively in the ILB group occurred consequentially. In addition, this was also supported that the respiratory rate at 0 hours postoperatively in the ILB group was higher than that of the later variables. The advantages of dorsolumbar epidural anesthesia include the use of smaller amounts of sedatives, use of local anesthesia, and high efficacy of local anesthesia for standing right paralumbar fossa omentopexy.8 Some disadvantages reported include the requirement of some anesthetic experience, inability to insert the epidural needle into the intervertebral space in 12.5% to 17% of cows,1,3 and recumbency in some cattle before surgery.3 Due to the occurrence of recumbency from the previously reported doses, xylazine was reduced from 1 to 0.8 mL and lidocaine was changed from 3 to 4 mL. These changes were successful in preventing recumbency from interrupting the surgery while reducing intra- and postoperative pain. In the EPI group, some cattle demonstrated tottering steps intra- and immediately postoperatively; however, no cows had disorder in the hind limbs at 17 hours postsurgery. In Japan, there has been a shift from ILB to EPI for inducing anesthesia before laparotomy in adult cows. The results of this study were considered to support these changes.
In dogs23 and cats,24,25 preoperative pain management is more successful and optimizes animal well-being. Steroids and NSAIDs are available in clinical practice,26 and local anesthesia and NSAIDs can reduce edema, hematoma, and swelling at the surgical site.3,6 The reason for the decrease in cortisol concentration in the ILB-F group immediately after surgery (0 hours) was thought to be that the preoperatively administered flunixin reduced the pain associated with surgery. Therefore, ILB-F was considered effective in suppressing intra- and postoperative pain and the inflammatory response at the surgical site. The side effects of NSAIDs include an increased risk of abomasal ulcers and renal failure.4 The reason for choosing flunixin as the NSAID in this study was its widespread use in Japan. As flunixin was administered only once before surgery in the ILB-F group, no cow exhibited symptoms of abomasal ulcers postoperatively.
In conclusion, ILB with preoperative IV administration of flunixin and EPI was observed to have the analgesic efficacy equal to or greater than ILB and considered useful in reducing intra- and postoperative stress of omentopexy. This study had high external validity, as it used clinical cases of cows; therefore, the results indicate that this preoperative treatment for laparotomy in cows can be immediately applied to clinical practice.
Supplementary Materials
Supplementary materials are posted online at the journal website: avmajournals.avma.org
Acknowledgments
The authors have nothing to declare.
We would like to thank Dr. Yokota and Dr. Yoshida for their cooperation in collecting data. We would like to thank Dr. Kato, Dr. Abe, and Dr. Ohtsuka for their support of our research.
References
- 1.↑
Edmondson MA. Local, regional, and spinal anesthesia in ruminants. Vet Clin North Am Food Anim Pract. 2016;32(3):535-552. doi:10.1016/j.cvfa.2016.05.015
- 2.↑
Anderson DE, Edmondson MA. Prevention and management of surgical pain in cattle. Vet Clin North Am Food Anim Pract. 2013;29(1):157-184. doi:10.1016/j.cvfa.2012.11.006
- 3.↑
Coetzee JF. Assessment and management of pain associated with castration in cattle. Vet Clin North Am Food Anim Pract. 2013;29(1):75-101. doi:10.1016/j.cvfa.2012.11.002
- 4.↑
King BD, Cohen RDH, Guenther CL, Janzen ED. The effect of age and method of castration on plasma cortisol in beef calves. Can J Anim Sci. 1991;71(2):257-263. doi:10.4141/cjas91-033
- 5.↑
Boesch D, Steiner A, Gygax L, Stauffacher M. Burdizzo castration of calves less than 1-week old with and without local anaesthesia: short-term behavioural responses and plasma cortisol levels. Appl Anim Behav Sci. 2008;114(3-4):330-345. doi:10.1016/j.applanim.2008.02.010
- 6.↑
Stock ML, Baldridge SL, Griffin D, Coetzee JF. Bovine dehorning: assessing pain and providing analgesic management. Vet Clin North Am Food Anim Pract. 2013;29(1):103-133. doi:10.1016/j.cvfa.2012.11.001
- 7.↑
Lee I, Yamada H. Epidural administration of fixed volumes of xylazine and lidocaine for anesthesia of dairy cattle undergoing flank surgery. J Am Vet Med Assoc. 2005;227(5):781-784, 741. doi:10.2460/javma.2005.227.781
- 8.↑
Hiraoka M, Miyagawa T, Kobayashi H, et al. Successful introduction of modified dorsolumbar epidural anesthesia in a bovine referral center. J Vet Sci. 2007;8(2):181-184. doi:10.4142/jvs.2007.8.2.181
- 9.↑
Niehaus AJ. Surgical management of abomasal disease. Vet Clin North Am Food Anim Pract. 2016;32(3):629-644. doi:10.1016/j.cvfa.2016.05.006
- 10.↑
Nichols S, Fecteau G. Surgical management of abomasal and small intestinal disease. Vet Clin North Am Food Anim Pract. 2018;34(1):55-81. doi:10.1016/j.cvfa.2017.10.007
- 11.↑
Pruessner JC, Kirschbaum C, Meinlschmid G, Hellhammer DH. Two formulas for computation of the area under the curve represent measures of total hormone concentration versus time-dependent change. Psychoneuroendocrinology. 2003;28(7):916-931. doi:10.1016/s0306-4530(02)00108-7
- 12.↑
Herskin MS, Munksgaard L, Ladewig J. Effects of acute stressors on nociception, adrenocortical responses and behavior of dairy cows. Physiol Behav. 2004;83(3):411-420. doi:10.1016/j.physbeh.2004.08.027
- 13.↑
Stafford KJ, Mellor DJ. Dehorning and disbudding distress and its alleviation in calves. Vet J. 2005;169(3):337-349. doi:10.1016/j.tvjl.2004.02.005
- 14.↑
Canozzi MEA, Mederos A, Manteca X, et al. A meta-analysis of cortisol concentration, vocalization, and average daily gain associated with castration in beef cattle. Res Vet Sci. 2017;114:430-443. doi:10.1016/j.rvsc.2017.07.014
- 15.↑
de Oliveira FA, Luna SPL, do Amaral JB, et al. Validation of the UNESP-Botucatu unidimensional composite pain scale for assessing postoperative pain in cattle. BMC Vet Res. 2014;10(10):200. doi:10.1186/s12917-014-0200-0
- 16.↑
Robertson SA, Steele CJ, Chen CL. Metabolic and hormonal changes associated with arthroscopic surgery in the horse. Equine Vet J. 1990;22(5):313-316. doi:10.1111/j.2042-3306.1990.tb04279.x
- 17.
Taylor PM. Effects of surgery on endocrine and metabolic responses to anaesthesia in horses and ponies. Res Vet Sci. 1998;64(2):133-140. doi:10.1016/s0034-5288(98)90008-x
- 18.↑
Stegmann GF, Jones RS. Perioperative plasma cortisol concentration in the horse. J S Afr Vet Assoc. 1998;69(4):137-142. doi:10.4102/jsava.v69i4.842
- 19.↑
Odore R, Badino P, Re G, et al. Effects of housing and short-term transportation on hormone and lymphocyte receptor concentrations in beef cattle. Res Vet Sci. 2011;90(2):341-345. doi:10.1016/j.rvsc.2010.05.026
- 20.↑
Chacon G, Garcia-Belenguer S, Villarroel M, Maria GA. Effect of transport stress on physiological responses of male bovines. Dtsch Tierarztl Wochenschr. 2005;112(12):465-469.
- 21.↑
Price DM, Lewis AW, Neuendorff DA, et al. Physiological and metabolic responses of gestating Brahman cows to repeated transportation. J Anim Sci. 2015;93(2):737-745. doi:10.2527/jas.2013-7508
- 22.↑
Skarda RT. Local and regional anesthesia in ruminants and swine. Vet Clin North Am Food Anim Pract. 1996;12(3):579-626. doi:10.1016/s0749-0720(15)30390-x
- 23.↑
Lemke KA, Runyon CL, Horney BS. Effects of preoperative administration of ketoprofen on anesthetic requirements and signs of postoperative pain in dogs undergoing elective ovariohysterectomy. J Am Vet Med Assoc. 2002;221(9):1268-1275. doi:10.2460/javma.2002.221.1268
- 24.↑
Carroll GL, Howe LB, Peterson KD. Analgesic efficacy of preoperative administration of meloxicam or butorphanol in onychectomized cats. J Am Vet Med Assoc. 2005;226(6):913-919. doi:10.2460/javma.2005.226.913
- 25.↑
Gassel AD, Tobias KM, Egger CM, Rohrbach BW. Comparison of oral and subcutaneous administration of buprenorphine and meloxicam for preemptive analgesia in cats undergoing ovariohysterectomy. J Am Vet Med Assoc. 2005;227(12):1937-1944. doi:10.2460/javma.2005.227.1937
- 26.↑
Otto KA, Short CE. Pharmaceutical control of pain in large animals. Appl Anim Behav Sci. 1998;59(1-3):157-169. doi:10.1016/S0168-1591(98)00130-0