Prolonging paracervical block anesthesia: addition of dextran to 2-chloroprocaine.

Forty parturient women received paracervical block (PCB) anesthetics during labor with 2-chloroprocaine (2-CP) and epinephrine in either normal saline or dextran. Thirty-six patients were though to have adequate anesthesia. Nineteen patients who recived 2-CP in saline had a mean duration of anesthesia lasting 55.4 min; one fetus developed post-PCB bradycardia. Seventeen patients who received 2-CP in dextran had a mean duration of anesthesia lasting 72.7 min; no fetal bradycardia was observed following PCB. Neonatal depression, expressed by 1 and 5 min Apgar scores below seven, was not observed in either group. The addition of dextran to 2-CP significantly prolongs the duration of PCB anesthesia and does not appear to compromise the fetus. The pain relief provided by a single PCB with 2-CP in dextran is still relatively short and would not persist throughout the active phase of labor in most parturient women.     

Electronic fetal monitoring in association with paracervical blocks

Three hundred and twenty-six patients in labor were monitored electronically during the administration of paracervical blocks. There were 129 primigravidas and 197 multigravidas in the study. Variable deceleration patterns during labor were observed in 128 patients. Of these, 109 cord problems such as overt and occult prolapse and nuchal entanglement were present. Sixty-five of these babies exhibited an Apgar score of 6 or less at one minute. There were 38 late deceleration patterns, 24 of which had placentas of 400 grams or less. Apgar scores of 6 or less were found in 20 of these infants. One hundred and nineteen infants or 36 per cent had a bradycardia episode after a paracervical block. The low Apgar scores appear to be related to other factors rather than to the paracervical block.     

Intrapartum paracervical block anesthesia with 2-chloroprocaine

Most of the reports of fetal bradycardia and acidosis following paracervical block anesthesia have involved the use of amide-linked anesthetics, such as lidocaine and mepivacaine. The purposes of this study were (1) to determine placental transfer of an ester-linked local anesthetic, 2-chloroprocaine, and its inactive metabolite, 2-chloroaminobenzoic acid (CABA) following paracervical block and (2) to evaluate the clinical use of 2-chloroprocaine for paracervical block anesthesia. Accordingly, 2-chloroprocaine was administered to 16 normal pregnant women in labor at term. Following injection, the levels of 2-chloroprocaine or CABA in maternal and neonatal plasma or urine were quantitated. Multiple clinical parameters, including the presence or absence of fetal bradycardia, were monitored before and after the paracervical block. The pharmacologic data indicated that 2-chloroprocaine is rapidly hydrolyzed. At delivery only trace levels of 2-chloroprocaine were present in 6.3% of the maternal samples and 25% of the cord vein samples. Furthermore, only 0.24% of the total dose of 2-chloroprocaine administered was recovered in neonatal urine as CABA. The clinical data showed no adverse effects on the parturient or neonate. Therefore, the data suggest that paracervical block anesthesia with 2-chloroprocaine may offer safe analgesia during the first stage of labor. Larger clinical studies appear warranted.     

Effects of local anesthetic agents on the uterine vasculatures and myometrium.

Intravascular procaine, lidocaine, mepivacaine, and bupivacaine decrease blood flow to the placental and nonplacental vascular beds of gravid ewes by stimulating vasoconstriction and myometrial contractility. These effects appear to be direct ones since they are not affected by alpha-adrenergic blockade. Dose-response curves determined in nonpregnant ewes indicate that significant decreases in blood flow may occur at arterial blood concentrations encountered clinically. It is proposed that reduced placental blood flow is the cause of fetal bradycardia following paracervical block anesthesia. The implications of these findings in obstetric anesthesia are discussed.     

Severe bradycardia and bradypnea following vaginal oocyte retrieval: a possible toxic effect of paracervical mepivacaine

We report a case of a patient with a history of heart conduction disease, symptom-free and without treatment in the last years, who experienced a severe cardiac complication associated with in vitro fertilization (IVF) with vaginal oocyte retrieval (VOR). Eighty-five minutes after the VOR a severe bradycardia and bradypnea occurred, requiring an emergency application of a pacemaker. Presumably the condition occurred because of a toxic effect of the 400 mg of mepivacaine administered paracervically. It is concluded that in the paracervical anesthesia in the IVF cycles the therapeutic range should be scrupulously followed in patients with heart condition.     

Bupivacaine paracervical block. Effects on the fetus and neonate.

To evaluate effects on the fetus and neonate, 53 paracervical blocks were administered to 38 low-risk parturients using a controlled superficial injection of 0.25% bupivacaine. Continuous fetal heart rate monitoring revealed no instance of bradycardia or late deceleration pattern. Apgar scores, cord arterial and venous pH values, and neurobehavioral evaluations of the neonates were similar to those observed in other low-risk patients. The effectiveness of pain relief of the blocks was less than expected or reported by other authors. Although we observed no harmful effects on the fetus or neonate from the superficial paracervical injection of bupivacaine, we did not find this combination of drug and technique to give dependable, effective pain relief in labor.     

Relationship of fetal bradycardia to maternal administration of lidocaine in sheep.

The casual relationship between the use of lidocaine and fetal bradycardia and the effect of the drug on maternal and fetal hemodynamics were studied on 13 chronically instrumented pregnant sheep. Lidocaine was infused intravenously to the mother for 60 minutes during arterial lidocaine concentrations were maintained at 2 to 5 microgram per milliliter in the mother and at less than 2 microgram per milliliter in the fetus. A decrease in uterine blood flow and an increase in uterine vascular resistance and uterine activity occurred immediately following the administration of lidocaine to the ewe. These changes were followed by a transient fetal bradycardia in 12 out of 17 experiments, accompanied by a decrease in fetal PaO2 values. These phenomena were seen in the absence of such predisposing conditions as maternal hypotension and fetal acidosis. It would appear that the mechanism responsible for a transient fetal bradycardia following regional obstetric anesthesia, particularly paracervical block anesthesia, in the initially nonasphyxiated fetus may in part be related to a brief decrease in perfusion of intervillous spaces. The bradycardia can occur at low lidocaine concentrations in both the maternal and fetal blood in a range similar to that observed in clinical practice.     

Fetal monitoring in a private hospital. Observations of fetal bradycardia following paracervical block anesthesia

One hundred and eight patients at Lutheran Hospital, a private community hospital, were willing subjects for this study of fetal heart rate patterns. Ninety-four patients received paracervical blocks. The fetal heart rate did not drop in 34.3 per cent. A drop in fetal heart rate was demonstrated in 28.4 per cent but not in the bradycardia range. Bradycardia was found in 37.3 per cent of those patients given paracervical block anesthesia for delivery.     

Pediatrician attendance at cesarean delivery: necessary or not?

OBJECTIVE: To determine whether it is necessary for a pediatrician to attend all cesarean deliveries. METHODS: We analyzed a database of 17,867 consecutive deliveries to determine the rates of low Apgar scores in the following three groups of patients: those with vaginal delivery, cesarean delivery using regional anesthesia without fetal indication, and cesarean delivery for fetal indications or using general anesthesia. RESULTS: There was a significantly higher rate of low Apgar scores in the fetal indications or general anesthesia group when compared with vaginal deliveries. Specifically, 35 (5.8%) of 596 cesareans for fetal heart rate abnormality or using general anesthesia had 1-minute Apgars under 4 in contrast to 115 of 10,270 (1.1%) of vaginal deliveries. There was no significantly increased risk for low Apgar scores in the group of cesareans using regional anesthesia for nonfetal indications (33 of 2057, 1.6%). Results were similar for Apgar scores under 7 at 5 minutes. CONCLUSION: Because there is no higher incidence of low Apgar scores in cesarean deliveries using regional anesthesia for nonfetal indications compared with vaginal deliveries, there is no convincing need for pediatrician attendance at such deliveries.     

Fetal heart rate and uterine activity following paracervical block

Bupivacaine without adrenaline was used for paracervical block (PCB) anesthesia in 60 low-risk parturients in whom there were no signs of fetal asphyxia. In order to evaluate its effects on fetus and uterine activity, 30 patients were given a "high dose" of 50 mg Bupivacaine, an amide-type local anesthetic agent, while 30 patients were given a "low dose" of 25 mg. Continuous fetal heart rate (FHR) monitoring in both study groups revealed nine patients with typically post PCB bradycardia and five patients with moderate PHR depression. All of them were born with excellent Apgar score. Although a decrease in fetal heart rate following PCB was noted in both groups more significant reduction was associated with the high dose block (P less than 0.05). In 11 cases, FHR depression was clearly associated with increased uterine activity, while in another three cases it was not (P less than 0.005). Oxytocin administration during the block did not affect fetal heart rate or uterine activity. The results indicate that FHR depression following PCB using Bupivacaine is dose dependent, transient and not dangerous to a normal fetus. No adverse maternal effects were noted. It is suggested that fetal heart rate depression following PCB using Bupivacaine is related to increased uterine activity.     

A randomized trial comparing local intracervical and combined local and paracervical anesthesia in outpatient hysteroscopy

STUDY OBJECTIVE: To compare the amount of pain during and after hysteroscopy using local intracervical and combined local and paracervical anesthesia. DESIGN: Prospective randomized trial (Canadian Task Force classification I). SETTING: University teaching hospital. PATIENTS: Eighty-four women who underwent outpatient hysteroscopy for evaluation of the uterine cavity at McGill University Health Center. INTERVENTIONS: Randomization to local intracervical or combined local and paracervical anesthesia. MEASUREMENTS AND MAIN RESULTS: Amount of pain experienced during the procedure and at 10, 30, and 60 minutes after the procedure was measured using a visual analog scale ranging from zero to 10 (zero = no pain; 10 = excruciating pain). The mean age of the patients in the local anesthesia group was 36.1 +/- 0.7 years and in the combined local and paracervical anesthesia group was 35.2 +/- 0.7 years. Patients experienced significantly more pain during than after the procedure. The mean pain scores in the local anesthesia group were significantly higher than in the combined anesthesia group during the procedure (3.2 +/- 0.3 vs 2.1 +/- 0.2; p <.01; 95% CI 0-2), 10 minutes after the procedure (1.9 +/- 0.2 vs 1.5 +/- 0.3; p = .03; 95% CI 0-1), and 30 minutes after the procedure (1.7 +/- 0.2 vs 1.0 +/- 0.2; p = .02; 95% CI 0-1). However, there was no significant difference in pain scores at 60 minutes after the procedure between the local anesthesia and combined anesthesia groups (0.9 +/- 0.2 and 0.7 +/- 0.1, respectively). CONCLUSIONS: Outpatient hysteroscopy with local or combined local and paracervical anesthesia was well tolerated by patients. However, combined anesthesia was associated with less pain during and at 10 and 30 minutes after the procedure. Most patients considered the pain as mild.     

Paracervical block in obstetrics

Paracervical block in 1,010 patients, with special emphasis on fetal bradycardia in a smaller group of 102 patients who had continuous monitoring of fetal heart rate with the Hon monitor, was studied. The results seem to indicate that bradycardia secondary to the block is transient and not dangerous to a normal fetus and does not seem to indicate fetal distress. One per cent Carbocaine¹ is a very effective and safe drug for the procedure. Contraindications to using the block include fetal distress and cases where delivery is expected to take place within the next 15 to 20 minutes. With careful technique, proper evaluation, and close observation of the patient, paracervical block would seem to be a safe procedure.     

Day-surgery operative hysteroscopy with loco-regional anesthesia

BACKGROUND: Nowadays hysteroscopic surgery offers the opportunity of treating in Day Hospital even patients who cannot undergo a traditional surgery because of high anesthesiological risk. The aim of this study is to prove that minimal invasive hysteroscopic procedures in loco-regional anesthesia can replace laparotomic gynecological surgery in many intrauterine lesions with the same effectiveness on pain and outcome. METHODS: From September 1999 to December 2000 at the Obstetric and Gynecological Department in Asti 200 hysteroscopic procedures have been performed. The patients (all i.v. line inserted, ECG and pulsometer monitored, and sublingual BDZ sedated) were divided into two groups: a group of 50 patients who underwent operation on paracervical block alone, and the other one of 150 women on paracervical block plus periorificial infiltration of local anesthetic. RESULTS: Only one woman in the first group paracervical block was totally insufficient and she needed a general anesthesia. In the same group, 44% of paracervical blocks required an additional conscious sedation with Propofol and Fentanyl. In the second group only 16 % of cases required an additional sedation. In all cases outcome was very good with complete recovery of the patients dismissed the same afternoon. CONCLUSIONS: In our experience operative hysteroscopies under loco-regional anesthesia with paracervical block and periorificial infiltration is a very satisfactory alternative to general anesthesia. Moreover the type of intrauterine lesion did not influence the tolerability of the operation.     

The maternal and fetal acid-base status during general or spinal anesthesia for elective cesarean section in the left tilt position

Thirty one healthy parturients received spinal or general anesthesia for elective cesarean section. Maternal blood pressures, maternal and fetal acid-base values, induction to delivery intervals (I-DI) and Apgar scores were determined. On spinal anesthesia, acute hydration by 6% hydroxyethyl starch solution and intramuscular injection of ephedrine were enforced prior to the block and in the left tilt position (17 degrees) oxygen inhalation immediately after the block was begun (group OII: 16 cases). As to general anesthesia, the same left tilt position was applied before the anesthesia by thiopental-0.5% halothane with-50% nitrous oxide in oxygen (group G: 15 cases). No significant decrease in maternal blood pressure was noticed, and maternal and the fetal acid-base status and Apgar scores were excellent in both groups. A positive correlation between umbilical venous pH values and 1 or 5 minutes Apgar scores was confirmed in group OII, and a negative correlation between 1 minute Apgar scores and I-DI was noticed in group G. Fetal acid-base values were not correlated with I-DI in either group, and it was postulated that placental or fetal circulation was sufficiently maintained. Biochemical status and clinical conditions in mothers and their infants are very favorable in well-conducted general or spinal anesthesia for elective cesarean section.     

Epidural and paracervical blockades in obstetrics. Catecholamines, arginine vasopressin and analgesic effect

A comparative study of analgesic and endocrinologic effects of obstetrical epidural anesthesia (EA, n = 23) and paracervical block (PCB, n = 39) was performed. Pain intensity was assessed on a horizontal linear scale. Simultaneously, blood samples for the determination of concentrations of norepinephrine (NE), epinephrine (E) and arginine vasopressin (AVP) were obtained. NE and AVP levels did not bear any relationship to pain scores. Instead, the average plasma E profile during labor was practically identical with the profile of pain scores. Plasma levels of E decreased significantly after EA. A similar but short-lived effect was observed also after PCB. When comparable doses of bupivacaine were used (30 mg in the EA group and 25 mg in the PCB group); initial pain relief after EA and PCB was similar, though after 30 min the pain score increased for patients who received the PCB, while patients who received EA had continued pain relief. Faster absorption of bupivacaine was observed after paracervical than epidural injection. Decreased variability was seen in the fetal cardiograms in 25% after EA and in 33% after PCB. Transient bradycardia was observed in 2 cases after paracervical injection.     

Ovarian puncture in fertilization in vitro: what analgesia?]

We compared two techniques of local anesthesia used in transvaginal ultrasound guided oocyte recovery in in vitro fertilization: paracervical lidoca?ne block versus vaginal application of Emla, a topical anesthesic cream. STUDY DESIGN: The study included 103 patients divided in two groups. Pain was evaluated by visual analog scale and questionnaire. RESULTS: Univariate analysis showed that the patients were satisfied with neither of the two protocols. Multivariate analysis revealed paracervical lidoca?ne block to be superior. The premedication appeared inadequate. CONCLUSION: We decide to use paracervical lidoca?ne block and to improve the premedication. Indications for general and locoregional anesthesia were also enlarged. A new study showed a significantly greater patient satisfaction. One variable analysis indicated that no one of these protocols satisfied our patients.     

Paracervical anaesthesia in outpatient hysteroscopy: a randomised double-blind placebo-controlled trial.

OBJECTIVE: To evaluate the efficacy and safety of paracervical anaesthesia in reducing pain during outpatient hysteroscopy and endometrial biopsy. DESIGN: Prospective, randomised, placebo-controlled, double-blind study. POPULATION: One hundred women undergoing outpatient hysteroscopy and endometrial biopsy for abnormal uterine bleeding. INTERVENTIONS: Paracervical block using 10 mL of either 2% lignocaine or normal saline before the procedure. MAIN OUTCOME MEASURES: Evaluation of pain at different stages of hysteroscopy using a visual analogue scale together with blood pressure and heart rate monitoring. RESULTS: Compared with placebo, paracervical anaesthesia significantly reduced the pain only at the time of insertion of the hysteroscope, but not at the subsequent stages of the procedure. However, paracervical injection of lignocaine resulted in a higher incidence of bradycardia and hypotension. CONCLUSIONS: Paracervical anaesthesia not only fails to reduce pain during outpatient hysteroscopy and endometrial biopsy, but also carries a risk of inducing bradycardia and hypotension, which is probably a result of inadvertent intravascular injection.     

A study of variable decelerations in association with other heart rate patterns during monitored labor.

A review of 1,011 consecutive intrapartum heart rate tracings yielded 37.3% with some degree of variable deceleration pattern. No differences in Apgar score distribution were observed in the presence of uncomplicated variable deceleration pattern when compared to those tracings marked normal. However, the presence of variable decelerations in association with other heart rate patterns resulted in lower mean Apgar scores at 1 and 5 minutes, which were significantly different from those of the fetal heart rate (FHR) normal group. Mean Apgar scores at 1 and 5 minutes were significantly different from normal when variable decelerations were noted in the presence of tachycardia and loss of variability. Mean Apgar scores were lower when bradycardia (prolonged episodes of heart rate less than 120 bpm) was present in the record when compared to normal, but the presence of variable decelerations with bradycardia did not result in different mean scores. The presence of baseline changes with loss of variability and variable decelerations appeared to result in the lowest mean scores. When bradycardia or tachycardia occurred in exclusive association with variable decelerations, the percentage of depressed newborn infants was relatively high.     

Prophylactic intrapartum amnioinfusion for patients with oligohydramnios. A prospective randomized study.

This prospective study evaluated whether prophylactic saline amnioinfusion among patients with amniotic fluid index (AFI) < or = 5.0 cm decreases the incidence of adverse fetal outcomes. Randomization of 53 patients with decreased AFI at term, resulted in 21 patients' receiving prophylactic saline amnioinfusion early in labor, prior to development of an abnormal fetal heart rate tracing. For the treatment group the mean AFI on admission was 3.0 cm, and the postamnioinfusion AFI was 8.9 cm. For 32 comparison (noninfusion) patients, the mean AFI was 2.9 cm; the group consisted of 17 patients randomized to receive no amnioinfusion (control group) and 15 patients who refused to participate in the study. There was no statistically significant difference between the amnioinfused and nonamnioinfused patients with regard to age, parity, gestational age, AFI at admission or duration of first or second stage of labor. Amnioinfusion resulted in no statistically significant reduction in the incidence of recurrent variable decelerations/bradycardia (26.3% vs. 46.6%), intrapartum resuscitation with terbutaline (5.2% vs. 10.0%), cesarean section for fetal distress (9.5% vs. 9.3%), fetal-acidosis (10.5% vs. 12.0%) or Apgar scores < 7 at five minutes (5.2% vs. 0%) in patients with oligohydramnios.     

The bupivacaine paracervical block in labor and its effect on quantitative uterine activity.

This study utilized internal fetal monitoring and an on-line voltage control oscillator for measurement of uterine activity unit (UAU) determination in patients who received a paracervical block (PCB) with the use of bupivacaine hydrochloride (Marcaine). The total dose of 25 mg (5 cc/side) of 0.25% bupivacaine used for PCB in 32 patients produced no ill effects to the fetus, as reflected by baseline fetal heart rate (FHR), beat-to-beat variablity, or Apgar scores. No adverse maternal effects were noted, and anesthesia was rated good or excellent in 81% of patients. Rate of cervical dilation remained the same or increased in 29 of 32 patients. Quantitative UAUs showed a significant decrease in the third 10-minute interval after block in primiparas, but no significant change in multiparas or in the group taken as a whole. Total UAUs before versus after PCB for either group or taken together were not statistically different. A decreasing trend in UAUs after PCB versus a positive regression line from activity prior to the block was noted.