Rat Model: Intrathecal Lipid for Total Spinal Block-Induced Hemodynamic Instability.

Objective: This study aimed to assess the potential of intrathecal administration of lipid emulsions as a targeted therapeutic strategy to mitigate the hemodynamic consequences of high or total spinal anesthesia induced by bupivacaine in a rat model. Materials and Methods: After receiving approval from Koç University's Local Ethics Board of Animal Experiments, 14 adult female Wistar Albino rats were randomized into two groups: Lipid and Saline. After inducing a high spinal block, each group was treated with either intrathecal lipid emulsions or isotonic saline solutions, respectively. Hemodynamic parameters such as systolic, diastolic, and mean arterial blood pressures, as well as heart rate, were continuously monitored. A histological analysis was conducted upon completion of the study. Results: The Lipid group exhibited a significant increase in mean systolic (p=0.002), diastolic (p=0.002), and arterial pressures (p=0.002) compared to the Saline group. The mean pulse rate also differed significantly between the groups (p=0.009). Notably, while all rats in the Saline group succumbed, only two fatalities occurred in the Lipid group, with the other five rats surviving (p=0.021). Conclusion: This study suggests that intrathecal administration of lipid emulsions can serve as a rapid and effective intervention to counteract the hypotension and bradycardia induced by high or total spinal anesthesia with bupivacaine in rats. While these findings are promising, further experimentation and clinical trials are required to confirm this method's potential, focusing on its long-term safety, efficacy, and the establishment of an optimal administration protoco.