Comparison of intraoperative nociception and postoperative acute pain after traditional or minimally invasive ovariohysterectomy in dogs

Many variations of ovariohysterectomy techniques have been described, including the traditional one and minimally invasive procedures. Non-laparoscopic Snook hook technique is an alternative for performing minimally invasive ovariohysterectomy. Few studies have been carried out in order to assess pain in animals submitted to minimally invasive surgeries, especially involving one of the most performed surgical procedures in veterinary practice. The aim of this study was to evaluate surgical duration, intraoperative nociception and acute postoperative pain after traditional ovariohysterectomy or minimally invasive non-laparoscopic technique in dogs using Snook hook. The hypothesis is that non-laparoscopic minimally invasive ovariohysterectomy would be faster and less painful than the conventional technique. Thirty dogs were divided into Traditional Group (TG = 15) and Minimally Invasive Group (MIG = 15). Heart rate, respiratory rate, systolic blood pressure, body temperature, oxyhemoglobin saturation, end-tidal carbon dioxide concentration (ETCO2) and end-tidal isoflurane concentration were evaluated before the surgery begins (M0), during incision (M1), clamping of the first ovarian pedicle (M2), second ovarian pedicle (M3), uterine cervix (M4), abdominal suture (M5) and at the end of surgery (M6). The modified Glasgow Pain Scale was used for acute postoperative pain assessment and Visual Analogue Scale (VAS) was used to assess the sensitivity of surgical wound. The level of significance established for all statistical analysis was 5%. Statistical differences were not observed between groups considering total surgical time and postoperative acute pain intensity (P > 0.05), in spite of MIG having shorter duration of surgery. There was no statistical difference between groups considering all intraoperative parameters except respiratory rate (TG < MIG; P < 0.05) and ETCO2 (MIG < TG; P < 0.05) at the moment of traction of the first ovarian pedicle (M2). Pain assessment by VAS showed statistical difference 24h after the end of surgery (TG < MIG) (P < 0.05). Both procedures were similar regarding intraoperative nociception and acute postoperative pain. It is possible that the sensation of pain in both procedures was blocked by the effectiveness of analgesics, once they might cause an inhibition of painful behaviors limiting a possible difference in pain identification. Higher respiratory stress observed in MIG at M2 and higher pain score by VAS noted in MIG 24 h after the end of surgery can be justified by greater traction of ovarian pedicle, due to limited surgical access of minimally invasive technique. Minimally invasive ovariohysterectomy non-laparoscopic seems to be potentially faster, probably due to the smaller size of the abdominal incision, which takes less time to be closed. In the present study, both techniques were performed by an experienced surgeon, providing safe procedures, nevertheless it is important to emphasize that iatrogenic injury can be caused by surgeons non-proficient in the Snook hook technique, considering the limited visualization of anatomical abdominal structures. Data obtained indicate that traditional ovariohysterectomy and non-laparoscopic Snook hook technique promote similar intraoperative nociception and acute postoperative pain, however minimally invasive procedure is potentially faster with less surgical trauma.(AU)

Meloxicam associado ou não ao tramadol no controle da dor após ovário-histerectomia videoassistida em cadelas / Meloxican with or without tramadol for control of pain undergoing laparoscopic-assisted ovariohysterectomy in bitches

O objetivo deste estudo foi avaliar a eficácia do meloxicam associado ou não ao tramadol, no controle da dor após ovário-histerectomia (OVH) laparoscópica com dois portais. Foram selecionadas 14 cadelas hígidas. Os animais foram separados de forma aleatória, em dois grupos. O grupo M (GM) recebeu meloxicam (0,2mg kg-1, s.i.d.), enquanto os animais do grupo MT (GMT) receberam a associação de meloxicam (0,2mg kg-1, s.i.d.) e tramadol (4mg kg-1, t.i.d.), ambos durante dois dias de pós-operatório. Para avaliação da dor pós-cirúrgica, foram utilizadas as escalas de Melbourne e escala visual analógica (EVA), além de mensurações de glicemia e cortisol sérico. Não houve diferença ao se avaliarem os grupos GM e GMT pela escala de Melbourne nem pela EVA. As mensurações de cortisol não atingiram valores superiores aos de referência para a espécie, enquanto os valores de glicemia não apresentaram variação significativa ao longo do tempo de avaliação nem entre grupos. Com os resultados deste estudo, foi possível concluir que a utilização de meloxicam associado ou não ao tramadol, nas doses e posologias propostas, é eficaz para controlar a dor pós-operatória de cadelas submetidas à OVH laparoscópica com dois portais.

The aim of this study was to evaluate the efficacy of meloxicam with or without tramadol for pain control after laparoscopic-assisted ovariohysterectomy (OVH) by two-portal access. Were selected 14 healthy dogs to perform video-assisted OVHs. The animals were divided randomly into two groups (GM and GMT). The GM group received meloxicam (0.2mg kg-1, s.i.d), whereas the GMT group received the combination of meloxicam (0.2mg kg-1, s.i.d) and tramadol (4mg kg-1, tid), both for two days after surgery. To evaluate the post-surgical pain Melbourne and EVA scales were used, and blood glucose and serum cortisol were measured. There was no statistical difference when evaluating GM and GMT groups and the Melbourne scale or the visual analogue scale VAS. Cortisol measurements did not reach values higher than the reference for the species, while blood glucose levels did not present significant statistical variation throughout the evaluation time or between groups. With these results, we concluded that the use of meloxicam with or without the tramadol at the doses and dosage schedules proposed, is effective to control postoperative pain in bitches that had undergone video-assisted OVH with two-portal access.

Acupuncture and pharmacopuncture are as effective as morphine or carprofen for postoperative analgesia in bitches undergoing ovariohysterectomy

ABSTRACT PURPOSE : To investigate the analgesic effect of acupuncture (AP) or micro-dose pharmacopuncture (PA), using carprofen or morphine, in bitches undergoing ovariohysterectomy (OHE). METHODS: Thirty five dogs were randomly assigned to five groups after sedation with acepromazine IM: AP, 0.5 mg.kg-1 of morphine subcutaneously (SC), 4 mg.kg-1 of carprofen SC, and PA with 0.05 mg.kg-1 of morphine or 0.4 mg.kg-1 of carprofen. Anaesthesia was induced with propofol and maintained with isoflurane. Pain was assessed after OHE by a blind observer for 24h, by dynamic visual analogue scale (DIVAS), Glasgow (CMPS-SF), Melbourne (UMPS) and Colorado University pain scale (CSU). Animals reaching 33% of the UMPS score received rescue analgesia with morphine IM. Non parametric data were analysed by Kruskal-Wallis or Friedman tests where applicable, followed by Dunn´s test. Parametric data were analysed by two way ANOVA, followed by Tukey test. RESULTS: There were no differences among groups in number of rescue analgesia. Except for the DIVAS score where animals treated with morphine had the lowest score compared with AP and carprofen, at 1h after surgery, there were no other differences among groups. CONCLUSION: Acupuncture or pharmacopuncture were equally effective as morphine or carprofen to control postoperative pain in bitches undergoing ovariohysterectomy.

Pain assessment in cats undergoing ovariohysterectomy by midline or lateral celiotomy through use of a previously validated multidimensional composite pain scale

PURPOSE: To assess pain in the immediate postoperative period in cats submitted into two different celiotomy techniques for ovariohysterectomy. METHODS: Fourteen healthy female cats up to three years old with a mean weight 2.75kg, without breed specification, were used in this double blind experiment. The animals were randomly assigned to two treatments: I- ovariohysterectomy by lateral approach (LA) or II - by midline approach (MA). The anesthesia consisted of acepromazine (0.1 mg.kg-1) and midazolam (0.25mg.kg-1) followed isoflurane vaporization to induce and maintain hypnosis. A bolus of fentanyl (5μg.kg-1) was administered intravenously to provide intraoperative analgesia. After surgery, pain scores were assessed through a multidimensional composite pain scale at four different times. RESULTS: Generally all factors related to psychomotor changes and pain expression showed higher scores in cats neutered by LA, but only psychomotor changes and total pain score presented statistical differences (p<0.05). The animals that underwent lateral celiotomy showed higher pain scores, at 1, 4 and 6 hours after surgery. CONCLUSIONS: Multidimensional analgesic scales were highly reliable. There was a tendency for the cats neutered by lateral approach to suffer more postoperative pain, including requiring a large number of analgesic rescues. .

Confiabilidade e pontuação mínima relacionada à intervenção analgésica de uma escala multidimensional para avaliação de dor pós-operatória em gatos / Reliability and cut-off point related to the analgesic intervention of a multidimensional composite scale to assess postoperative pain in cats

Avaliou-se a confiabilidade e determinou-se a pontuação mínima relacionada à necessidade de intervenção analgésica de uma escala multidimensional para avaliação de dor pós-operatória em gatas submetidas à ovário-histerectomia. Trinta gatas foram filmadas em quatro momentos predeterminados: pré-operatório, pós-operatório antes e depois da analgesia de resgate e às 24 horas após a cirurgia. Quatro observadores, não cientes dos momentos de avaliação, e um observador, considerado padrão-ouro - pesquisador que desenvolveu a escala - , avaliaram os vídeos em ordem aleatória, a partir da aplicação da escala, e determinaram a suficiência ou não de analgesia, baseando-se na experiência clínica. Os vídeos foram reavaliados dois meses após a primeira análise. O grau de concordância entre as avaliações dos diferentes observadores e das avaliações feitas pelo mesmo observador em diferentes ocasiões foi verificado pelo coeficiente de correlação intraclasse, que variou entre bom e muito bom para todos os itens da escala, exceto atividade, atitude e miscelânea de comportamentos que apresentaram confiabilidade moderada. O ponto de corte ótimo (> 7) foi selecionado pela análise descritiva e da curva Receiver Operating Characteristic. Os resultados suportam a confiabilidade em termos de reprodutibilidade e estabilidade e indicam que a terapia analgésica deve ser considerada em pontuações >8.

The aim with this study was to evaluate the reliability, and to establish the minimum score relating to the analgesic intervention of a multidimensional scale for use in assessing postoperative pain in cats undergoing ovariohysterectomy. Thirty cats were video recorded at 4 predetermined moments: prior to surgery, before and after rescue analgesia postoperatively, and 24 hours after surgery. Four observers blind to the times of assessment, and a gold standard observer (researcher who developed the scale) evaluated the video segments in random order using the scale, and determined the adequacy or not of analgesia based on clinical experience. The videos were reassessed two months after the first analysis. The agreement between the assessment of different observers, and the assessment made by the same observer on different occasions has been verified by the intra-class correlation coefficient that ranged from good to very good for all scale items, except activity, attitude and miscellaneous behaviors, which showed moderate reliability. The optimal cutoff point (> 7) was selected based on descriptive analysis and Receiver Operating Characteristic curve. The findings support the reliability in terms of reproducibility and stability, and indicate that analgesic therapy should be considered in scores >8.

A comparison of extradural tramadol and extradural morphine for postoperative analgesia in female dogs undergoing ovariohysterectomy / Tramadol peridural comparativamente à morfina para analgesia pós-operatória em cadelas submetidas à ovariosalpingohisterectomia

PURPOSE: To compare the postoperative analgesic effects of the extradural tramadol or morphine in female dogs undergoing ovariohysterectomy. METHODS: Sixteen female dogs were randomly assigned to two groups of eight animals each and received morphine (0.1mg kg-1 M group) or tramadol (2mg kg-1 T group). The pre-anesthetic medication was intravenously (iv) acepromazine (0.05mg kg-1). Anesthesia was induced with propofol (4mg kg-1iv) and maintained with isoflurane. The degree of analgesia was evaluated using a numerical rating scale that included physiologic and behavior variables. Dogs were scored at one, three, six and 12 hours after surgery by one blinded observer. Dogs were treated with morphine (0.5mg kg-1) if their scores were >6. Serum cortisol was measured before the pre-anesthetic medication was administered (basal), at the time of the ovarian pedicle clamping (T0), and at 1 (T1), 6 (T6) and 12 (T12) hours postoperative. RESULTS: The pain score did not differ between morphine and tramadol treatments. Rescue analgesia was administered to one dog in the T treatment group. Serum cortisol did not differ between treatments. CONCLUSION: The extradural administration of morphine or tramadol is a safe and effective method of inducing analgesia in female dogs undergoing ovariohyterectomy.

OBJETIVO: Comparar o efeito analgésico pós-operatório do tramadol em relação à morfina quando utilizados por via peridural em cadelas submetidas à ovariosalpingohisterectomia (OSH). MÉTODOS: Dezesseis cadelas foram aleatoriamente distribuídas em dois tratamentos, com oito animais em cada, tratadas com morfina (0,1mg kg-1, M) e tramadol (2mg kg-1, T). A medicação pré-anestésica foi feita por via intravenosa (iv) com acepromazina (0,05mg kg-1), seguindo-se indução e manutenção anestésicas com propofol (4mg kg-1 iv) e isofluorano, respectivamente. O grau de analgesia foi avaliado uma, três, seis e 12 horas após o término da cirurgia, com escala descritiva numérica, que incluiu a observação de alterações fisiológicas e comportamentais. Animais com escore > 06 foram tratados com morfina (0,5mg kg-1). A concentração sérica de cortisol foi mensurada antes da sedação (basal), ao término da cirurgia (T0), 1 (T1), 6 (T6) e 12 (T12) horas após a cirurgia. RESULTADOS: Os escores de dor e a concentração sérica de cortisol não diferiram entre os tratamentos. Analgesia de resgate foi necessária em um cão do tratamento T. CONCLUSÃO: A administração peridural de morfina e de tramadol resulta em analgesia adequada e de longa duração em cadelas submetidas à ovariosalpingohisterectomia.