Preemptive treatment of sympathetic blockade during spinal anesthesia in pregnant women with slow administration of low dose atropine

TUBAY Preemptive Treatment of Sympathetic Blockade During Spinal Anesthesia in Pregnant Women with Slow Administration of Low Dose Atropine Bolu Abant İzzet Baysal University Department of Anesthesiology and Reanimation. Master Thesis. Bolu, 2024 Objective: Spinal anesthesia is a neuraxial anesthesia method frequently used in elective cesarean section operations due to its easy application, rapid onset of action, good sensory block and its advantages over general anesthesia. Hypotension due to sympathetic blockade is a common condition in patients undergoing spinal anesthesia, and severe hypotensive conditions are undesirable complications. A combined approach is recommended for the prevention and treatment of hypotension, including adequate fluid support (crystalloids or colloids), low-dose spinal anesthesia, appropriate vasopressors (such as ephedrine, phenylephrine), and the use of atropine, a parasympatholytic agent, when bradycardia develops. Rather than administering vasopressors after a drop in blood pressure has occurred, the latest algorithms recommend using vasopressors prophylactically. Atropine was tried with fixed dose and fixed time planning to balance the sympathetic blockade due to spinal anesthesia in cesarean section cases, but it was found ineffective. In our study, we investigated the possible beneficial effect of preemptive administration of an atropine dose proportional to the patient's weight as soon as a 15% decrease in heart rate was detected. Methods: After the ethics committee approval and the written patient consent were obtained, 84 patients who underwent elective cesarean section under spinal anesthesia were included in the study. As premedication before the intervention, all patients were given Decort 8 mg IV for antiemetic purposes. Patients were monitored noninvasively and systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (OCP), heart rate (HR), oxygen saturation (SpO2) and respiratory rates were recorded. Two vascular accesses were established in all cases with 18 G (Gauge) intravenous cannulas. All cases were preoperatively preloaded with 300 cc of 0.9% NaCl intravenously over 15 minutes. After all patients were placed on the operating table and given an anatomical position suitable for spinal anesthesia in a sitting position, spinal anesthesia was applied with 14 mg of 0.5% isobaric bupivacaine from the L3-L4 or L4-L5 intervals. After spinal anesthesia, the patients were immediately placed in the supine position. After spinal anesthesia, 5 ml/kg/hour 0.9% NaCl solution was given to the patients in both groups as maintenance fluid throughout the operation. In both groups, after the patient was placed on the table, SAP, DAP, MAP, HR and SpO2 measurements were recorded at 1-minute intervals until the baby came out, and at average 3-minute intervals after the baby came out. In the ephedrine group, 5 mg/mL ephedrine was used in a bolus dose for sympathetic blockade (SAP<100) and the dose was repeated if necessary. When bradycardia occurred in this group (<65/min HR), Atropine 0.5 mg/mL was administered and repeated if necessary. In the atropine group, Ephedrine 5 mg/mL was administered in repeated doses when necessary (SAP<100) and when bradycardia expectation (10% decrease in peak heart rate after spinal anesthesia) developed, 0.4 mg/4mL diluted Atropine was administered as a slow bolus in 20 seconds. Parameters such as total ephedrine consumption, HR, SAP, DAP, MAP values, nausea and vomiting were evaluated in both groups. Results: Among all patients, only 5 patients in the atropine group had to be administered a single dose of Ephedrine: 5/33, (15/100). Theoretically, we tried not to use Ephedrine at all in the Atropine group; however, due to the procedure, we had to use Ephedrine for the benefit of the patient in 5 of the 33 patients in the Atropine group. A single dose of 5 mg Ephedrine was used in 3 of these 5 patients, and 5 mg Ephedrine was used twice in 2 patients. Although no vomiting was observed in either group, the incidence of nausea was significantly less in the Atropine group. (p = 0.004235) Discussion: Results have shown that preemptive IV Atropine administration may be a useful alternative in reducing the use of Ephedrine in the treatment of sympathetic blockade due to spinal anesthesia in pregnant women undergoing cesarean section. It was observed that statistically and clinically significantly different Ephedrine doses were used between the two groups. Ephedrine use was not needed in 28 of 33 patients in the Atropine group. Total Ephedrine consumption in 5 patients in the Atropine group was 35 mg. The frequency of nausea was also observed to be significantly lower in the Atropine group. Vomiting was not observed in both groups. The results we obtained in this study can also be interpreted that it may be possible to treat sympathetic blockade without an alphamimetic agent by applying only Atropine, with dose adjustments made through ECG monitoring with artificial intelligence and related calculations. Conclusion: In this study, we demonstrated that early diagnosis of sympathetic blockade due to spinal anesthesia during cesarean section in pregnant women can be predicted through the proportional decrease in heart rate, thus hypotension and bradycardia can be prevented with a single drug with a low side effect profile, such as Atropine. We also believe that if artificial intelligence applications are implanted, the treatment of sympathetic blockade due to spinal anesthesia in caesarean section operations will approach perfection.