The effect of the addition of ropivacaine or bupivacaine upon pruritus induced by intrathecal fentanyl in labour

Sixty patients in early labour were randomly allocated to one of three groups. The control group received intrathecal fentanyl 25 microg, the ropivacaine group received intrathecal fentanyl 25 microg and ropivacaine 2.5 mg while the bupivacaine group received intrathecal fentanyl 25 microg and bupivacaine 2.5 mg. The incidence of pruritus was 100% in controls, compared with 85% in the ropivacaine group (not significant) and 75% in the bupivacaine group (p = 0.003). The severity of pruritus was significantly less in the ropivacaine (p = 0.006) and bupivacaine (p = 0.001) groups. Most patients developed pruritus by 30 min. Pruritus above the abdomen was not reduced in patients receiving local anaesthetics. There were no significant differences in the mean pain visual analogue score, systolic blood pressure, maternal heart rate and upper level of reduced pin-prick sensation in the first 30 min. Intrathecal ropivacaine and, more so, intrathecal bupivacaine reduce the incidence and severity of pruritus from intrathecal fentanyl for labour analgesia.     

Ondansetron does not prevent pruritus induced by low-dose intrathecal fentanyl

BACKGROUND: Addition of an opioid to low-dose spinal anesthesia with bupivacaine improves the quality and success of anesthesia. However, the intrathecal fentanyl-induced pruritus is as high as 75%. We hypothesized that after administration of 4 or 8 mg of prophylactic IV ondansetron, the incidence of pruritus induced by low-dose intrathecal fentanyl would be significantly lower than after placebo. METHODS: In this double-blind study, 90 outpatients undergoing knee arthroscopy received 3 mg of bupivacaine + 10 micro g fentanyl intrathecally. Before spinal puncture, the patients received randomly either saline (P) or ondansetron 4 mg (O4) or 8 mg (O8) IV. They were asked about pruritus frequently, and they estimated its severity on a scale of 0-10. RESULTS: There was no difference in the incidence of pruritus between the three groups: pruritus occurred in 17 (57%), in 21 (75%) and in 19 patients (70%) in P, O4 and O8 groups, respectively. The pruritus was mostly mild. Four patients in the placebo group, three in the O4 and four patients in the O8 groups considered it severe. One patient in each group requested treatment for pruritus; after IV naloxone their pruritus was relieved. Neither time to pruritus nor duration of pruritus differed between the groups. One patient in each group developed a long-lasting (>10 h) pruritus. CONCLUSIONS: After prophylactic administration of 4 or 8 mg of ondansetron IV, the incidence, duration and severity of pruritus were similar to placebo. Ondansetron does not prevent pruritus induced by low-dose intrathecal fentanyl.     

Optimal dose of intrathecal isobaric bupivacaine in total knee arthroplasty

Purpose

Early mobilization is an important aspect of fast-track protocols and intrathecal bupivacaine is often used in primary total knee arthroplasty (TKA). Although the optimal dose is not known, conventional doses leave patients unable to mobilize for two to four hours. The dose of an intrathecally administered local anesthetic should therefore be optimized to achieve immediate postoperative mobilization. This study determined the median effective dose (ED) of intrathecal bupivacaine for primary unilateral TKA.

Methods

Between April 2016 and February 2017 all patients who qualified for unilateral primary TKA were eligible for inclusion. In this dose-finding study, the up-and-down method by Dixon and Massey was used, which is a sequential allocation model. Patients received a dose of isobaric bupivacaine according to the outcome of the preceding patient with an initial starting dose of 5 mg. The dose was increased or decreased by steps of 0.5 mg, depending on the outcome of the preceding patient. During surgery, patients were closely monitored for indications of pain. Time points of regaining motor and sensory functions were determined.

Results

Twenty-five patients were included. Mean (SD) age was 70.1 (8.8) yr old, median [IQR] body mass index was 29.5 [27.3-30.9 kg·m^?2], and 48% were female. In 11 patients the dose was inadequate; of these, nine patients needed additional anesthesia during surgery, and in four of these nine patients a conversion to general anesthesia was required. The median ED was 3.5 (95% confidence interval [CI], 3.1 to 4.0) mg of intrathecal bupivacaine. The calculated ED50 was 3.4 (95% CI, 2.7 to 4.0) mg; the calculated ED95 was 5 (95% CI, 3.7 to 8.0) mg.

Conclusion

In this small study with tight control over operative duration, the median effective dosage of intrathecal isobaric bupivacaine for primary unilateral TKA was 3.5 mg and the ED95 was 5 mg. Reduction of conventional dosages of intrathecal bupivacaine is feasible at centres using fast-track arthroplasty protocols.

     

Comparison of intrathecal fentanyl and diamorphine in addition to bupivacaine for caesarean section under spinal anaesthesia

Background. Co-administration of small doses of opioids andbupivacaine for spinal anaesthesia reduces intraoperative discomfortand may reduce postoperative analgesic requirements in patientsundergoing Caesarean section. Fentanyl and diamorphine are thetwo most frequently used agents in UK obstetric anaestheticpractice. Methods. Seventy-five healthy parturients scheduled for electiveCaesarean section under spinal anaesthesia using hyperbaric0.5% bupivacaine, were randomly allocated to additionally receiveintrathecal fentanyl 20 µg, diamorphine 300 µg or0.9% saline. Patients also received i.v. cyclizine and rectaldiclofenac. Results. Less supplementary intraoperative analgesia was requiredby patients in either opioid group (4%) compared with the control(32%) (P<0.05). Twenty four hours after spinal injection,total mean (SD) postoperative morphine requirement was significantlylower if diamorphine was administered (31 (21) mg), in comparisonwith the other two groups (control 68 (26) mg; fentanyl 62 (26)mg) (P<0.05). Reduced visual analogue pain scores were evident12 h following diamorphine, but observed only for 1 h afterfentanyl when compared with the control (P<0.05). Mild pruritiswas more common for 2 h after either spinal opioid (P<0.05),but no inter-group differences were observed for the remainderof the first 24 h. Patients displayed deeper levels of sedationboth acutely and 12 h after administration of intrathecal fentanyl(P<0.05). Conclusions. Both intrathecal opioids reduce intraoperativediscomfort, but only diamorphine reduced postoperative analgesicrequirement beyond the immediate postoperative period. Br J Anaesth 2002; 89: 452–8     

Low-dose bupivacaine does not improve postoperative epidural fentanyl analgesia in orthopedic patients

Epidural infusions of 10 micrograms/mL fentanyl combined with low-dose bupivacaine (0.1%) were compared with epidural infusions of fentanyl alone for postoperative analgesia after total knee joint replacement. There were no detectable differences between the two groups in analgesia (visual analogue scale ranging between 15 and 40 mm), infusion rates (which averaged 7-9 mL/h), or serum fentanyl levels (which reached 1-2 ng/mL). The incidence of side effects, including nausea, vomiting, and pruritus, was also similar. Of the patients receiving fentanyl and low-dose bupivacaine, one developed a transient unilateral motor and sensory loss, and one developed significant hypotension and respiratory depression. The addition of low-dose bupivacaine does not improve epidural fentanyl infusion analgesia after knee surgery and may increase morbidity.     

Direction of injection does not affect the spread of spinal bupivacaine in parturients

Purpose

One of the factors that can affect the distribution of local anaesthetic solutions in the subarachnoid space is the direction of the spinal needle through which injections are made. This study investigated the effect of the direction of the aperture of the Whitacre needle on the spread of hyperbaric bupivacaine in parturients undergoing elective caesarean section.

Methods

Forty healthy term parturients scheduled for caesarean delivery under spinal anaesthesia with 12 mg hyperbanc bupivacaine + 0 2 mg morphine were randomly assigned to one of two groups: needle onfice cephalad (1) or caudad (11). Spinal blocks were administered in the sitting position with patients being positioned supine immediately after. A blinded observer assessed the dermatome level of analgesia to ice every minute for the first 10 minutes, every three minutes for the following 35 min, then every 15 mm until the sensory level regressed to T₀.

Results

There was no difference between the groups regarding the maximal number of segments blocked cephalad to T (11.4 ± 3.4: group 1 and 12.0 ± 3.4: group II). time to highest cephalad spread of sensory block (22 ± 10: group 1 and 19 ± 10 mm: group II). or time to regression to T₀ (164 ± 26: group 1 and 153 ± 24 mtn: group II). The maximum decrease in blood pressure (33.9 ± 9.6: group 1 and 36.8 ± 11.8 mmHg: group II) and dosage of ephedrine administered (14.7 ± 10.7: group 1 and 16.2 ± 11.0 mg: group II) did not differ.

Conclusion

The direction of the aperture of the Whitacre needle does not influence the spread of hyperbanc bupivacaine in the term parturient.     

Either sufentanil or fentanyl, in addition to intrathecal bupivacaine, provide satisfactory early labour analgesia

PURPOSE: The study was aimed primarily at comparing the duration of analgesia produced by intrathecal fentanyl 25 microg with sufentanil 5 microg when added to bupivacaine 1.25 mg as the initial component of the combined spinal epidural (CSE) technique in early labour. METHODS: Forty healthy parturients were randomly assigned into two groups to receive either intrathecal sufentanil 5 microg plus bupivacaine 1.25 mg (Group S) or intrathecal fentanyl 25 microg plus bupivacaine 1.25 mg (Group F). Apart from the duration of analgesia, pain scores and side effects were also evaluated. RESULTS: There was no significant difference in the duration of analgesia (mean 109 +/- SD 49 min in Group F vs 118 +/- 54 min in Group S, P=0.9). Group F had a more rapid onset of analgesia (P <0.05) and a higher cephalad block (median T4 vs T7, P <0.05) in the first 30 min after the block. No difference in the side effects was detected. CONCLUSION: Fentanyl 25 microg is a good alternative to sufentanil 5 microg when added to bupivacaine 1.25 mg for early labour analgesia.     

Low dose epidural bupivacaine/fentanyl infusion does not mask uterine rupture

A patient is described in whom the symptoms and signs of uterine rupture were not masked by combined spinal epidural analgesia with an epidural infusion of 0.1% bupivacaine and 1.5 microg ml(-l) fentanyl. Early recognition of the dehiscence of a previous caesarean section scar resulted in an excellent neonatal and maternal outcome.     

Minimum local analgesic dose of intrathecal bupivacaine in labor and the effect of intrathecal fentanyl

BACKGROUND: Combining bupivacaine with fentanyl for intrathecal analgesia in labor is well recognized, but dosages commonly used are arbitrarily chosen and may be excessive. This study aimed to determine the median effective dose (ED50) of intrathecal bupivacaine, defined as the minimum local analgesic dose (MLAD), and then use this to assess the effect of different doses of fentanyl. METHODS: In this double-blind, randomized, prospective study, 124 parturients receiving combined spinal epidural analgesia at 2-6-cm cervical dilatation were allocated to one of four groups to receive bupivacaine alone or with 5, 15, or 25 microg fentanyl, using the technique of up-down sequential allocation. Analgesic effectiveness was assessed using 100-mm visual analog pain scores, with less than or equal to 10 mm within 15 min defined as effective. MLAD was calculated using the formula of Dixon and Massey. Pruritus and duration of spinal analgesia were also recorded. RESULTS: Minimum local analgesic dose of intrathecal bupivacaine was 1.99 mg (95% confidence interval, 1.71, 2.27). There were similar significant reductions in MLAD (P < 0.001) for all bupivacaine-fentanyl groups compared with bupivacaine control. There was a dose-dependent increase in both pruritus and duration of spinal analgesia with increasing fentanyl (P < 0.0001). CONCLUSION: Under the conditions of this study, the addition of intrathecal fentanyl 5 microg offers a similar significant bupivacaine dose-sparing effect as 15 and 25 microg. Analgesia in the first stage of labor can be achieved using lower doses of fentanyl, resulting in less pruritus but with a shortening of duration of action.     

The addition of hydromorphone to epidural fentanyl does not affect analgesia in early labour

PURPOSE: Epidural fentanyl after a lidocaine and epinephrine test dose, provides adequate analgesia and allows for ambulation during early labour. The current study was designed to determine the influence of hydromorphone added to an epidural fentanyl bolus (e.g., whether there is an increase in duration of analgesia). METHODS: Forty-four labouring primigravid women, at less than 5 cm cervical dilation, who requested epidural analgesia were enrolled in this randomized, double-blind study. After a 3 mL test dose of lidocaine with epinephrine, patients received fentanyl 100 microgram (in 10 mL volume). They randomly received the fentanyl with either saline or hydromorphone (300 microgram). After administration of the initial analgesic, pain scores and side effects were recorded for each patient at ten, 20, and 30 min, and every 30 min thereafter, by an observer blinded to the technique used. RESULTS: The patients were taller in the hydromorphone group (P < 0.04). There were no other demographic differences between the two groups. The mean duration prior to re-dose was not significantly different in the group that received hydromorphone (135 +/- 52 min) compared to the control group (145 +/- 46 min). Side effects were similar between the two groups. No patient in either group experienced any detectable motor block. CONCLUSION: In early labouring patients, the addition of hydromorphone (300 microgram) to epidural fentanyl (100 microgram after a lidocaine and epinephrine test dose) neither prolongs the duration of analgesia nor affects the ability to ambulate, and cannot be recommended according to the current study.     

The addition of fentanyl to epidural bupivacaine in first stage labour

Epidural analgesia was studied in 100 healthy Chinese women with uncomplicated pregnancies in first stage labour. Patients were randomly allocated to receive 8 ml of one of the following five solutions: bupivacaine 0.125% with fentanyl 50 micrograms or fentanyl 100 micrograms, bupivacaine 0.25% plain, bupivacaine 0.25% with fentanyl 50 micrograms or fentanyl 100 micrograms. There was no difference in quality of analgesia among groups as measured by the reduction of visual analogue pain scores 20 minutes after the epidural dose. The duration of analgesia was similar among groups with the overall median duration being 105 minutes. There was no difference in method of delivery or neonatal Apgar scores. The least concentrated mixture providing good quality analgesia for the first stage of labour was the combination of bupivacaine 0.125% with fentanyl 50 micrograms.     

The effect of intrathecal fentanyl added to hyperbaric bupivacaine for caesarean section

BACKGROUND: Management of cesarean section with spinal anesthesia is often accompanied with intraoperative nausea and pain. In a randomized controlled study, we explored the effect of intrathecal fentanyl on the characteristics of subarachnoid block in patients undergoing cesarean section. METHODS: Twenty-four healthy parturients scheduled for elective Cesarean section were allocated to receive either fentanyl 0.3 ml (15 micrograms) or 0.9% saline 0.3 ml added to 0.5% hyperbaric bupivacaine 2.0 ml given intrathecally in the right decubitus position (n = 12 in each group). Level of sensory blockade was evaluated with cold test and intraoperative use of antiemetics and analgesics was recorded. RESULTS: The maximum level of sensory blockade was significantly higher in the fentanyl group as compared with the control group (P = 0.019). Use of intraoperative antiemetics was significantly less often in the fentanyl group (P = 0.007). The required amount of intraoperative analgesics was smaller in the fentanyl group, although the difference was not significant (P = 0.11). No remarkable side effects, such as respiratory depression and hypoxia were observed. Apgar scores in the newborn were similar. CONCLUSION: Addition of intrathecal fentanyl to hyperbaric bupivacaine in parturients undergoing cesarean section improved quality of anesthesia without producing significant side effects.     

Comparison of intrathecal fentanyl and bupivacaine in combined spinal-epidural obstetric analgesia

OBJECTIVES: To compare intrathecal injection of the opioid fentanyl to injection of bupivacaine, in terms of their effect of labour in the context within the combined spinal-epidural analgesia. METHODS: Prospective single-blind trial in primiparas randomized to 2 groups for sedation with 25 microg of fentanyl or 2.5 mg of bupivacaine, followed in both cases by epidural infusion of ropivacaine. We measured time from puncture to delivery of the neonate, rescue analgesia, pain assessed on a visual analog scale (VAS), motor block, side effects, sensory level, Apgar score, and maternal satisfaction. RESULTS: Sixty-four women were studied. The mean time elapsed between puncture and birth was 168.59 minutes (95% confidence interval [CI], 134.16 to 203.03 minutes) in the bupivacaine group and 189.13 minutes (95% CI, 151.93 to 226.32 minutes) in the fentanyl group. The mean difference was -20.53 minutes (95% CI, -70.21 to 29.15 minutes). Survival analysis applied to duration of labor, using type of delivery as the final outcome, also failed to show a significant between-group difference (chi2=0.59, P=.447). No significant differences in use of rescue analgesia, VAS scores, or motor block were observed. The incidence of pruritus in the fentanyl group was 34.37%, but there were no differences in maternal satisfaction. CONCLUSIONS: Our findings do not support the use of intradural fentanyl with the aim of shortening labor. Fentanyl leads to more pruritus, although this side effect does not affect maternal satisfaction.     

Appropriate dose of isobaric bupivacaine with fentanyl in spinal anesthesia for cesarean section

BACKGROUND: Spinal anesthesia combined with fentanyl is commonly used for cesarean section. We studied the appropriate dose of isobaric bupivacaine for spinal anesthesia when combined with a fixed dose of 20 microg fentanyl. METHODS:Forty-seven women scheduled for cesarean section were allocated into four-groups according to the dose of 0.5% isobaric bupivacaine with 20 microg fentanyl; 1.0 ml (n=5), 1.5 ml (n=11), 2.0 ml (n=11), and 2.5 ml (n=20). RESULTS: The requirement of epidural anesthesia for pain relief or muscle relaxant was less in the 2.0 ml and 2.5 ml groups than the other groups. However, dyspnea due to high spinal anesthesia developed in 3 subjects out of 20 in the 2.5 ml group. CONCLUSIONS: Two ml of 0.5% isobaric bupivacaine was the most appropriate dose for cesarean section, when combined with 20 microg of fentanyl.     

The ED50 and ED95 of intrathecal isobaric bupivacaine with opioids for cesarean delivery

BACKGROUND: The ideal intrathecal isobaric bupivacaine dose for cesarean delivery anesthesia is uncertain. While small doses (5-9 mg) of bupivacaine may reduce side effects such as hypotension, they potentially increase spinal anesthetic failures. This study determined the ED50 and ED95 of intrathecal isobaric bupivacaine (with adjuvant opioids) for cesarean delivery. METHODS: After institutional review board approval and written informed consent were obtained, 48 parturients undergoing elective cesarean delivery under combined spinal-epidural anesthesia were enrolled in this double-blind, randomized, dose-ranging study. Patients received a 5-, 6-, 7-, 8-, 9-, 10-, 11-, or 12-mg intrathecal isobaric bupivacaine dose with 10 microg fentanyl and 200 microg morphine. Overall anesthetic success was recorded when no intraoperative epidural supplement was required during the cesarean delivery. ED50 and ED95 values for overall anesthetic success were determined using a logistic regression model. RESULTS: ED50 and ED95 values for overall anesthetic success were 7.25 and 13.0 mg, respectively. No advantages for low doses could be demonstrated with regard to hypotension, nausea, vomiting, pruritus, or maternal satisfaction, although this study was underpowered to detect significant differences in secondary outcome variables. CONCLUSIONS: The ED50 and ED95 values (7.25 and 13.0 mg, respectively) for intrathecal isobaric bupivacaine in this circumstance are similar to values the authors determined recently for hyperbaric bupivacaine using similar methodology. These ED50 and ED95 values are significantly higher than those advocated in previous reports in which success was claimed using lower intrathecal bupivacaine doses. The current study used stricter criteria to define "successful" anesthesia and support the use of larger bupivacaine doses to ensure adequate patient comfort.     

Experimental arthritis in the rat does not alter the analgesic potency of intrathecal or intraarticular morphine.

To explore further the role of inflammatory processing on peripheral opioid pharmacology, we examined whether the potency of intraarticular (i.a.) or intrathecal (i.t) morphine in tests of thermal and mechanical nociception changed during the induction of experimental arthritis in the rat. Thermal nociception by i.t. morphine (3, 10, and 50 micrograms) or i.a. morphine (100, 1000, and 3000 micrograms) was assessed by means of a modified Hargreaves box ever) 28 h. Mechanical antinociception was determined for the largest applied doses of morphine using von Frey hairs. Morphine produced dose-dependent thermal antinociception after i.t. or i.a. administration: a 50% increase in maximum antinociceptive thermal response (50% effective dose) was produced by i.t. doses of 9.7 micrograms at the start and 9.1 micrograms at the end of this 28-h observational interval, whereas after i.a. administration, 50% effective dose values were 553 micrograms at the start and 660 micrograms at the end. The largest applied dose of either i.t. or i.a. morphine produced mechanical antinociception. On Day 1, the antinociceptive effect for mechanical nociception (expressed as the area under the curve of the percentage of maximal possible effect values at 0.5, 1, 2, and 4 h) was 68% for i.t. morphine 50 micrograms and 53% for i.a. morphine 3000 micrograms. Neither result differed from the corresponding area under the curve values on Day 2. Naloxone administered either i.t. or i.a. abolished the antinociceptive action of morphine given at the same site. We conclude that, although morphine has a peripheral analgesic site of action in a rat arthritis model, its potency for both i.a. and i.t. routes of administration does not change during the onset of arthritis. Implications: In this animal study, we showed that the administration of morphine modulates thermal and mechanical antinociception at central and peripheral sites in inflammatory pain.     

Epinephrine is not a useful addition to intrathecal fentanyl or fentanyl-bupivacaine for labor analgesia

BACKGROUND AND OBJECTIVES: Intrathecal fentanyl provides effective labor analgesia for a limited time with frequent side effects. We evaluated the effects of adding epinephrine to intrathecal fentanyl with and without bupivacaine. METHODS: Eighty healthy, term, nulliparous parturients with cervical dilation of 5 cm or less received combined spinal-epidural (CSE) analgesia. Subjects were randomized in a double-blind fashion to 1 of 4 intrathecal solutions containing fentanyl 35 microg with either saline (F); bupivacaine 2.5 mg + saline (FB); bupivacaine 2.5 mg + epinephrine 100 microg (FBE); or epinephrine 100 microg + saline (FE). Patients were evaluated for visual analog pain score, duration of spinal analgesia (time until patient request for additional analgesia), nausea/vomiting, pruritus, sensory and motor block, maternal blood pressure, and fetal heart rate (FHR). RESULTS: Intrathecal bupivacaine significantly prolonged fentanyl analgesia with or without epinephrine (P =.018), but epinephrine did not significantly prolong the duration of fentanyl alone or with bupivacaine (F, 92 +/- 39 minutes; FB, 125 +/- 31 minutes; FBE, 134 +/- 42 minutes; and FE, 117 +/- 48 minutes). Intrathecal epinephrine was associated with a higher incidence of severe nausea (P =.001), and the FBE group had more lower extremity weakness (P =.047). There was no difference in the incidence of severe pruritus, FHR deceleration, or delivery outcome between the groups. CONCLUSIONS: These results suggest that intrathecal epinephrine does not prolong the duration of fentanyl or fentanyl with bupivacaine for labor analgesia in nulliparous parturients. Additionally, intrathecal epinephrine did not decrease the incidence of side effects and therefore cannot be recommended.     

Determination of the ED95 for intrathecal plain bupivacaine combined with fentanyl in active labor

BACKGROUND: Combined spinal-epidural (CSE) analgesia is an effective technique for pain control in labor and is particularly useful in the active phase. Excessive doses of intrathecal bupivacaine may be associated with adverse effects. This study is designed to estimate the ED95 for intrathecal plain bupivacaine with fentanyl 15 microg in labor. METHODS: Forty healthy women in active labor (cervical dilatation > or = 5 cm and verbal numeric pain score > or = 6/10) were given CSE for labor analgesia with intrathecal plain bupivacaine and fentanyl 15 microg. The initial dose of bupivacaine was 1.75 mg. Doses were varied in a 0.25-mg testing interval according to a method of sequential allocation designed to cluster the dose around the ED95. Effectiveness was defined as a verbal numeric pain score < or = 1 within 10 min of intrathecal injection. RESULTS: There was a 100% response rate to the 1.75-mg dose (95% CI 84.6-100.0%) and an 85.0% response rate to 1.50 mg (95% CI 64.0-95.8%). The ED95 for intrathecal plain bupivacaine with fentanyl 15 microg in active labor was 1.66 mg (95% CI 1.50-482.5 mg). The incidence of fetal bradycardia was 7.5%. The incidence of pruritus was 55%. No patient experienced motor block. CONCLUSIONS: This is the first dose-finding study specifically designed to estimate the ED95 of intrathecal bupivacaine combined with a fixed amount of fentanyl for analgesia in active labor. The combination of bupivacaine 1.75 mg with fentanyl 15 microg rapidly and reliably alleviated pain in the active phase of labor.