Impact evaluation of two different general anesthesia protocols (TIVA with propofol vs isoflurane) on the total number of interventions to treat cardiovascular depression or arousal/movement episodes in dogs undergoing orthopedic surgery receiving an intrathecal anesthesia

Abstract

The aim of this prospective, randomized clinical trial was to compare the total number of anesthetic interventions (TNAI) performed by the anesthetist to treat cardiovascular depression or arousal/movement episodes in dogs receiving intrathecal and general anesthesia (GA), maintained using propofol-based TIVA (group P) or isoflurane (group I). Mean arterial pressure (MAP) before (T₀) and 12 min after intrathecal anesthesia (T₁) and intraoperative vasoactive consumption were also compared. The TNAI to deepen the anesthetic plane or to treat hemodynamic depression in the pre-surgical and intra-surgical period was calculated in forty-two client-owned dogs randomly assigned to group P or I. Ten dogs for each group complied with the inclusion criteria and were analyzed. In pre-surgical period, the TNAI was higher in Group I [2 (0-5)] than Group P [0 (0-2)] (P=0.022), and ephedrine consumption was also higher in Group I [75 (0-200) µg/kg)] than Group P [(0 (0-50)] (P=0.016). MAP (mmHg) in Group P was 79 (66-95) at T₀ and 65 (59-86) at T₁ and 67.5 (50-73) and 57 (53-66) in Group I, respectively. At T₀ and T₁, MAP was higher in Group P (P=0.005 and P=0.006, respectively). No differences were found between the two groups in the intrasurgical period (P>0.05). This study shows that the GA protocol can have a relevant impact on the TNAI performed by the anesthetist in the pre-surgical period of anesthesia, to treat cardiovascular depression or arousal/movement episodes in dogs receving intrathecal anesthesia.

Fig. 1.

Box plots of the mean arterial pressure (MAP) before (T₀) and 12 min after intrathecal injection (T₁) in Groups P and I. MAP is higher in dogs in the Group P compared with those in Group I at T₀ (P=0.0005) and T₁ (P=0.006). Dots refer to the value of individual cases. The whiskers show the range values, the width of the box shows the interquartile range, and the bar in the box is the median value.

Fig. 2.

Box plots of the total number of anesthetic interventions to deepen the anesthetic plane or to treat hemodynamic depression in the pre-surgical period is higher in Group I than in Group P (P=0.022). Dots refer to the value of individual cases. The whiskers show the range values, the width of the box shows the interquartile range, and the bar in the box is the median value.