DOI: https://doi.org/10.21203/rs.3.rs-1434995/v1
Background: Dezocine is a novel opioid receptor-antagonistic analgesic, which is widely used in clinic work. However, its usage in cesarean section is rare.
Case presentation: A 28-year-old woman of 38 weeks' gestation (163cm, 79kg) underwent emergency cesarean section because of pelvic outlet stenosis in November 2021. There was no history of preeclampsia, anticoagulation, or hemorrhagic diathesis. The most recent electrocardiogram (ECG) during pregnancy was sinus tachycardia, and the heart rate (HR) was 108 beats/min. After the accomplishment of spinal anesthesia, the cesarean section started smoothly. After the fetus was delivered, the patient complained of pain when suturing the skin. The anesthesiologist gave her dezocine 5mg and the parturient presented with hypertensive crisis merging paroxysmal supraventricular tachycardia (PSVT). The fastest HR was 178 beats/min and the highest blood pressure (BP) was 190/128mmHg. After Esmolol 20mg and Urapidil 12.5mg were administrated, her HR and BP returned normal range 3min later. After observation, the patient returned to the ward one hour later and left hospital after 5 days. The patient denied the history of PSVT and hyperthyroidism.
Conclusion: Nowadays，dizocine has been widely used in the area of postoperative analgesia. However, its usage is rare in obstetrics and gynecology. The malignant adverse reactions of dizocine needs to be highly vigilant.
The rate for caesarean sections to be between 10% and 15% is the ideal rate considered by the international healthcare community since 1985. Since then, caesarean sections have become increasingly common in both developed and developing countries. The cesarean section rate in China has increased from 5% in the 1960s to 20% in the early 1990s, and has continued to rise in recent 20 years. Some literature reports show that the cesarean section rate in many domestic hospitals is between 40% - 60%, and even more than 70% in some hospitals.
Dezocine is a novel opioid receptor-antagonistic analgesic, which has been mainly applied as postoperative, visceral, and carcinogenic analgesics. In general, the peak value can reach within 10–90 minutes after intramuscular or intravenous injection, and the average terminal half-life is 2.4 hours [1]. The analgesic effect was like or slightly higher than that of morphine, but there were fewer mental dependence and related adverse reactions. Dezocine can be used safely and effectively for postoperative obstetric analgesia [2,3]. However, its side effects have not been fully described and it is possible that the initial dose of dizocine may be overestimated. We report a series of hypertensive crisis merging paroxysmal supraventricular tachycardia (PSVT) after intravenous administration of dizocine 5mg.The patient gave written informed consent for publication of this case report.
A 28-year-old woman of 38 weeks' gestation (163cm, 79kg) underwent emergency cesarean section because of pelvic outlet stenosis in November 2021. She had no history of preeclampsia, anticoagulation, or hemorrhagic diathesis. The physical examination and pre-operative blood tests including coagulation function, urine analysis, and chest radiograph were all within normal limits. The most recent ECG in pregnancy was sinus tachycardia, heart rate 108bpm.When the patient arrived in the operating room, the L3 to L4 subarachnoid space was accessed at the first attempt using a 27-gauge needle; 10mg 0.375% bupivacaine was injected into the subarachnoid space. After the fetus was delivered, the patient complained of pain when suturing the skin. After she received dezocine 5mg intravenously about 1min, she presented with hypertensive crisis merging paroxysmal supraventricular tachycardia (PSVT). The fastest heart rate was 178 beats/min (Fig.1) and the highest blood pressure was 190/128mmHg (Fig.2). She was given Esmolol 20mg and Urapidil 12.5mg. After 3 min she regained an effective heart rate and blood pressure returned normal limit. After observation, the patient returned to the ward one hour later. The patient denied the history of PSVT and hyperthyroidism.
In order to eliminate the inducement of hypertensive crisis merging PSVT, the patient was immediately examined for thyroid function, myocardial enzyme, catecholamine, and arterial blood gas electrolyte. All the examination were in normal limits. Because the whole cesarean section process was smooth, oxytocin was not used, and the amount of bleeding was about 320ml, which ruled out the cause of oxytocin; There was no special discomfort in the patient's heart during the follow-up visit the next day, and the results of cardiac color Doppler ultrasound were normal. Subsequently, her course was uneventful and she returned home 5 days later.
The appearance of hypertensive crisis merging PSVT linked to the injection of dezocine is the most probable explanation in our report. Even though there were no relevant studies and medical records, it was mentioned in the drug manual that a patient had tachycardia after intramuscular injection of dizocine, with a maximum heart rate of 112beats/min [4]. Although the catecholamine test results of the patient were normal, we did not rule out the possibility of occult pheochromocytoma. Because the patient refused to Enhance CT, we still could not exclude the possibility of occult pheochromocytoma. Considering that the hypertensive crisis caused by occult pheochromocytoma needs some inducements, we think it is unlikely to diagnose occult pheochromocytoma [5]. The mechanism of dezocine induced supraventricular tachycardia complicated with hypertensive crisis is still unclear. Although dizocine is widely used in postoperative analgesia [6,7], its malignant adverse reactions needs to be highly vigilant.
ECG: electrocardiogram; HR: heart rate; PSVT: paroxysmal supraventricular tachycardia.
Ethics approval and consent to participate
Written consent for the publication of this case report was obtained from the patient. Approval for case report by the institutional ethics committee is not required.
Consent for publication
Written informed consent for the publication of this case report and for the accompanying images was obtained from the patient. A copy of the written consent is available for review by the Editor-in-Chief of this journal.
Availability of data and materials
All data generated or analyzed during this study are included in this manuscript.
Competing interest
The authors declare that they have no competing interests.
Funding
None.
Authors' contributions
HLP prepared the manuscript and provided the images. YML reviewed the manuscript. All authors read and approved the final manuscript.
Acknowledgements
None.