The anaesthetic records of 1525 dogs were examined to determine the prevalence of postanaesthetic hypothermia, its clinical predictors and consequences. Temperature was recorded throughout the anaesthesia. At the end of the procedure, details coded in were: hyperthermia (>39.50°C), normothermia (38.50°C-39.50°C), slight (38.49°C-36.50°C), moderate (36.49°C-34.00°C) and severe hypothermia (<34.00°C). Statistical analysis consisted of multiple regression to identify the factors that are associated with the temperature at the end of the procedure. Before premedication, the temperature was 38.7 ± 0.6°C (mean ± sd). At 60, 120 and 180 minutes from induction, the temperature was 36.7 ± 1.3°C, 36.1 ± 1.4°C and 35.8 ± 1.5°C, respectively. The prevalence of hypothermia was: slight, 51.5 per cent (95 per cent CI 49.0 to 54.0 per cent); moderate, 29.3 per cent (27.1-31.7 per cent) and severe: 2.8% (2.0-3.7%). The variables that associated with a decrease in the temperature recorded at the end of the anaesthesia were: duration of the preanesthetic time, duration of the anaesthesia, physical condition (ASA III and ASA IV dogs showed lower temperatures than ASA I dogs), the reason for anaesthesia (anaesthesia for diagnostic procedures or thoracic surgery reduce the temperature when compared with minor procedures), and the recumbency during the procedure (sternal and dorsal recumbencies showed lower temperatures than lateral recumbency). The temperature before premedication and the body surface (BS) were associated with a higher temperature at the end of the anaesthesia, and would be considered as protective factors.

This paper describes the cardiorespiratory variables and the incidence of anaesthetic complications in dogs. For this, a retrospective study of 1281 anaesthesias was performed. Heart rate (HR), non-invasive mean arterial (MAP), systolic (SP) and diastolic pressures (DP), invasive mean arterial (IMAP), systolic (ISP) and diastolic pressures (IDP), central venous pressure (CVP), respiratory rate (RR), tidal volume (V(T)), minute volume (V(M)), end-tidal CO(2) (EtCO(2)), arterial oxygen saturation (SpO(2)), temperature (T) and death are reported. Data were described both globally and separately for each ASA (American Society of Anaesthesiologists classification) status. An ANOVA and a Tukey's test were used for comparing the different ASA status' values (alpha=0.05). During anaesthetic maintenance, the mean +/- SD of the studied variables were: HR: 91+/-27 bpm. MAP: 86+/-24 mmHg. IMAP: 80+/-22 mmHg. SP: 114+/-25 mmHg. ISP: 109+/-26 mmHg. DP: 67+/-23 mmHg. IDP: 66+/-22 mmHg. CVP: 5+/-3 mmHg. RR: 19+/-11 rpm. V(T): 14+/-7 ml/kg. V(M): 191+/-93 ml/kg/min. EtCO(2): 40+/-8 mmHg. T: 37.1+/-1.7 degrees C. ASA III and ASA IV patients, compared with those with ASA I, showed higher values of HR, RR, V(T) and V(M) and lower in IMAP, CVP, EtCO(2), SpO(2) and T. The most frequent complications were bradycardia (36.3% of the patients), hypotension (37.9%), hypoventilation (63.4%), hypoxia (16.4%), hypothermia (4.8%) and death (0.9%). Cardiorespiratory complications frequently occur in dogs during general anaesthesia.

A retrospective study of 275 anaesthetic records of cats was undertaken to examine the prevalence of postanaesthetic hypothermia, its clinical predictors and consequences. Temperature was recorded throughout anaesthesia. The temperature reached at the end was classified as hyperthermia (>39.50 °C), normothermia (38.50 to 39.50 °C), slight hypothermia (38.49 to 36.50 °C), moderate hypothermia (36.49 to 34.00 °C) or severe hypothermia (<34.00 °C). Statistical analysis consisted of multiple regression to identify the factors that affect the temperature at the end of the procedure. Before premedication, the mean (sd) temperature was 38.2 (1.0) °C. At 60, 120 and 180 minutes from induction, the temperature was 35.4 (1.4) °C, 35.0 (1.5) °C and 34.6 (1.5) °C, respectively. The prevalence of hypothermia was slight 26.5 per cent (95 per cent CI 21.7 to 32.0 per cent), moderate 60.4 per cent (95 per cent CI 54.5 to 66.0 per cent) and severe 10.5 per cent (95 per cent CI 7.4 to 14.7 per cent). The variables associated with a decrease in the temperature recorded at the end of anaesthesia were the duration of anaesthesia, the reason for anaesthesia (abdominal and orthopaedic surgeries significantly reduced the temperature when compared with minor procedures) and the anaesthetic risk (high-risk cats showed lower temperatures than low-risk cats). The temperature before premedication was associated with an increase in the final temperature.

The purpose of this study was to assess the clinical effects of dexmedetomidine, both alone and combined with pethidine or butorphanol, in cats. A prospective randomized blind study was performed. Thirty cats were randomly assigned to three groups of 10 animals: D: dexmedetomidine (20 μg/kg IM); DP: dexmedetomidine (10 μg/kg IM) and pethidine (2.5 mg/kg IM); DB: dexmedetomidine (10 μg/kg IM) and butorphanol (0.4 mg/kg IM). Quality of sedation, analgesia, muscle relaxation and the possibility of performing some clinical procedures were compared using a multifactorial scale. Sedation, analgesia and muscle relaxation increased progressively over time and did not differ in the three protocols. The three protocols facilitated the completion of several clinical procedures. The clinical variables studied showed a similar behaviour in the three protocols and remained close to the baseline, except for a drop in heart rate in protocol D. In conclusion, dexmedetomidine, either alone or combined with pethidine or butorphanol, offers suitable sedation, analgesia and relaxation to perform various clinical procedures in cats.

Quadratus lumborum block (QLB) is used to provide analgesia for abdominal surgery in humans. The aim of this study was to assess an anaesthetic protocol involving the QLB for canine ovariohysterectomy. Ten dogs were included. Anaesthetic protocol consisted of premedication with IM medetomidine (20 μg kg−1) and SC meloxicam (0.1 mg kg−1), induction with propofol to effect, and maintenance with sevoflurane in oxygen/medical air. QLB was performed injecting 0.4 mL kg−1 of 0.25% bupivacaine/iohexol per side. Computed Tomography (CT) was performed before and after surgery. Fentanyl was administered as rescue analgesia during surgery. The Short Form of The Glasgow Composite Pain Scale and thermal threshold (TT) at the level of the elbow, T10, T13 and L3 were assessed before premedication and every hour postoperatively. Methadone was given as rescue analgesia postoperatively when pain score was >3. A Yuen’s test on trimmed means for dependent samples was used to analyse the data (p < 0.05). CT images showed spreading of the contrast/block for a median (range) of 3 (2–5) vertebrae, without differences between preoperative and postoperative images. One dog needed rescue analgesia during surgery. Pain score was less than 4/24 in all the animals during the first 4 h after surgery. TT showed a significant increased signal in all the areas tested, apart from the humerus, 30 min after surgery. The QLB may provide additional analgesia for canine ovariohysterectomy. Further studies are needed to assess the specific contribution of the QLB in abdominal analgesia.