Hemodynamic Stability of Bupivacaine With and Without Adrenaline for Paracervical Block for Cervical Conization During General Anesthesia: A Randomized Controlled Double Blinded Study
Hemodynamic Stability of Bupivacaine With and Without Adrenaline for Paracervical Block for Cervical Conization During General Anesthesia: A Randomized Controlled Double Blinded Study
Cervical conization is done for pre-cancer disease. The procedure is performed with local anesthesia and general anesthesia. Local anesthesia is given by paracervical block, and several different local anesthetics is being used including bupivacaine with and without adrenaline. Adrenaline might reduce local bleeding and reduce toxicity of bupivacaine by reducing absorption, but might affect cardiovascular function. This study will examine this effect.
Most patients scheduled for cervical conization are healthy, young women. Some do this procedure with local anesthesia (paracervical block) and sedation, others general anesthesia combined with local anesthesia. Lidocaine with adrenaline is often used, but some uses longer acting substances like bupivacaine 2,5 mg/ml with adrenaline 5 microg/ml.
Adding of adrenaline prolongs the effect of anesthesia and the effect is probably strongest for short-acting local anesthetics. Adrenaline may delay absorption of local anesthetics avoiding toxic plasma concentrations and reduce local bleeding. Injection of local anesthetics with adrenaline may affect haemodynamic stability.
Para-cervical block has been used for analgesia in first stage of labor, but may give foetal bradycardia in 3-4 % and may affect the cardiotocogram in 10-12%. This effect is observed with bupivacaine and the less toxic levobupivacaine. Because of fear for complications and foetal injury this block has been replaced by more effective and safer methods like epidural and spinal anesthesia.
In gynecological practice the para-cervical block is still used for termination of pregnancy, cervical conization and for instrumentation of uterus.
We have observed affection of hemodynamic stability when using local anesthetics with adrenaline in nasal mucosa and during cervical conization. Some patients may experience increase or decrease in blood pressure and heart rate with a duration of 3-5 minutes.
Kerkkamp and coworkers have observed an 64% increase in cardiac output when using bupivacaine with adrenaline 100 microg epidurally but de Leeuw et al find an effect of less than 10% change in cardiac output during combined psoas compartment and ischiadic-block. We have performed a non-randomized, non-blinded pilot-study showing a 86% increase in systolic blood pressure and 65% increase in cardiac output after para-cervical block with bupivacaine 50 mg and adrenaline 100 microg. We want to confirm these results by doing a randomized, blinded study.
Most day-surgical patients are classified as ASA (American Society of Anesthesiologists) grade 1-2, and the complication rates are low. Still we may experience cardiovascular events during anesthesia with patients considered without cardiovascular diseases. Hemodynamic stability during anesthesia is a goal for all patients.
LiDCOplus (Lithium Dilution Cardiac Output) is a minimal invasive hemodynamic monitor for measuring cardiac output (CO) and systemic resistance (SVR). It uses two algorithms. PulseCO is an analysis of artery-waveform and gives nominal values. LiDCO is calibration with a small dose Lithium and gives absolute values. This study will examine relative changes, and calibration is not necessary.
The primary endpoints with respect to the hemodynamic effects of the interventions are group differences in systolic blood pressure and cardiac output the first 0-10 minutes after intervention. Secondary endpoints are other hemodynamic variables as stroke volume (SV), heart rate (HR), and systemic vascular resistance (SVR).
Demographic data and baseline measurements will be presented as mean (SD) if normally distributed or as median and range if not normally distributed, and group differences will be tested using the one-way ANOVA or Kruskal-Wallis tests, respectively. Baseline hemodynamic values represent measurements collected before administration of local anesthesia.
Inclusion Criteria:
• Clinical diagnosis of cervical pre-cancer
Exclusion Criteria: