Isobaric Ropivacaine 5 mg/mL for Spinal Anesthesia in Children

Mepivacaine dosing for spinal anesthesia in pediatric orthopedic surgery: a retrospective chart review

BACKGROUND

Mepivacaine is an intermediate-acting local anesthetic used for spinal anesthesia in adults. Currently, there are no published dosing guidelines for spinal mepivacaine in patients under age 18.

AIMS

The purpose of this study is to describe the clinically used doses of mepivacaine by weight and age for orthopedic surgery in pediatrics.

METHODS

We performed a retrospective chart review of patients aged 0-18 who received mepivacaine for spinal anesthesia from 2016 to 2022. We performed a secondary analysis for patients aged 0-18 who received spinal anesthesia with bupivacaine or chloroprocaine.

RESULTS

The data extraction yielded 3627 single-shot mepivacaine spinals. Patient age ranged from 5 to 18 years. Median dosage in milligrams/kilograms (mg/kg) of mepivacaine was calculated for each age group. Our analysis revealed that dosage in mg/kg decreased by patient age and began to plateau at age 15. Bupivacaine was the most common single-shot spinal agent in patients under age 10. After age 10, mepivacaine was more common. Chloroprocaine began to be used in patients older than 8 years.

CONCLUSIONS

We describe mepivacaine dosage as a function of age and weight in patients younger than 18 years. As age and weight increased, a lower dose of mepivacaine per kg was administered for spinal anesthesia.

Comparison of block characteristics of intrathecal isobaric levobupivacaine versus isobaric ropivacaine for infra-umbilical surgeries in school-age children: A prospective randomised double-blind study

Background and Aims:

Levobupivacaine and ropivacaine are effective local anaesthetic drugs used in regional anaesthesia with low cardio-neurotoxicity profile than bupivacaine, but comparative studies are limited in children. So, we compared these two drugs intrathecally to study their efficacy and safety in school-age children.

Methods:

This study was carried out in 60 American Society of Anesthesiologists class I, II and III patients aged 6–12 years, of either sex undergoing infra-umbilical surgeries. After institutional ethical committee approval and written informed consent, the patients were randomly divided into two groups. Group A received isobaric levobupivacaine (0.5%, 0.3-0.4 mg/kg), whereas group B received isobaric ropivacaine (0.5%, 0.5 mg/kg) intrathecally. Fentanyl (0.2 μg/kg) was used as an adjuvant in both the groups. Onset, peak and duration of sensory and motor blockade, duration of post-operative analgesia, time for micturition, perioperative haemodynamic parameters and complications were compared.

Results:

Onset and peak of sensory and motor block were earlier in group A. Significantly longer duration of sensory and motor block was achieved in group A (251 ± 41 min, 201 ± 40 min) compared to group B (211 ± 21 min, 102 ± 16 min) (P < 0.001). The time to first rescue analgesic was also significantly prolonged in group A (270 ± 39 min) compared to group B (233 ± 18 min) (P < 0.001). Time to micturition was much early in group B (157 ± 27 min) compared to group A (225 ± 31 min) (P < 0.001).

Conclusion:

Intrathecal isobaric levobupivacaine and ropivacaine with fentanyl produces effective surgical anaesthesia and postoperative analgesia without any adverse effects. Early regression of sensorimotor blockade makes ropivacaine better in comparison to levobupivacaine for short infra-umbilical surgeries in children.

Recent trends in paediatric regional anaesthesia

Paediatric regional anaesthesia today is one of the fastest growing and exciting aspects of paediatric anaesthesia, which requires an ongoing fervour to learn. Application of paediatric regional anaesthesia in neonates, infants, toddlers and children is undertaken to treat perioperative pain without disturbing the physiological milieu with additional advantages elaborated in the review. The available choices, traditional methods and the most recently described methods are discussed with emphasis on their advantages and disadvantages. Clear pointers for selection of the blocks are also discussed. To present a holistic overview of this rapidly growing subject, a comprehensive literature search was performed in May 2019 in MEDLINE, PubMed and Google Scholar to retrieve articles pertaining to all the above topics. The keywords used in various combinations included 'Central neuraxial, blocks, Paediatric(s)', 'Peripheral Nerve blocks', 'Safety, controversies, regional, anaesthesia'.

Spinal anesthesia in children: A review

Even after a vast safety record, the role of spinal anesthesia (SA) as a primary anesthetic technique in children remains contentious and is mainly limited to specialized pediatric centers. It is usually practiced on moribund former preterm infants (<60 weeks post-conception) to reduce the incidence of post-operative apnea when compared to general anesthesia (GA). However, there is ample literature to suggest its safety and efficacy for suitable procedures in older children as well. SA in children has many advantages as in adults with an added advantage of minimal cardio-respiratory disturbance. Recently, several reports from animal studies have raised serious concerns regarding the harmful effects of GA on young developing brain. This may further increase the utility of SA in children as it provides all components of balanced anesthesia technique. Also, SA can be an economical option for countries with finite resources. Limited duration of surgical anesthesia in children is one of the major deterrents for its widespread use in them. To overcome this, several additives like epinephrine, clonidine, fentanyl, morphine, neostigmine etc. have been used and found to be effective even in neonates. But, the developing spinal cord may also be vulnerable to drug-related toxicity, though this has not been systematically evaluated in children. So, adjuvants and drugs with widest therapeutic index should be preferred in children. Despite its widespread use, incidence of side-effects is low and permanent neurological sequalae have not been reported with SA. Literature yields encouraging results regarding its safety and efficacy. Technical skills and constant vigilance of experienced anesthesia providers is indispensable to achieve good results with this technique.

Spinal blocks

Every anesthetist should have the expertise to perform lumbar puncture that is the prerequisite to induce spinal anesthesia. Spinal anesthesia is easy and effective technique: small amount of local anesthetic injected in the lumbar cerebrospinal fluid provides highly effective anesthesia, analgesia, and sympathetic and motor block in the lower part of the body. The main limitation of spinal anesthesia is a variable and relatively short duration of the block with a single-injection of local anesthetic. With appropriate use of adjuvant or combining spinal anesthesia with epidural anesthesia, the analgesic action can be controlled in case of early recovery of initial block or in patients with prolonged procedures. Contraindications are rare. Bleeding disorders and any major dysfunction in coagulation system are rare in children, but spinal anesthesia should not be used in children with local infection or increased intracranial pressure. Children with spinal anesthesia may develop the same adverse effects as has been reported in adults, but in contrast to adults, cardiovascular deterioration is uncommon in children even with high blocks. Most children having surgery with spinal anesthesia need sedation, and in these cases, close monitoring of sufficient respiratory function and protective airway reflexes is necessary. Postdural puncture headache and transient neurological symptoms have been reported also in pediatric patients, and thus, guardians should be provided instructions for follow-up and contact information if symptoms appear or persist after discharge. Epidural blood patch is effective treatment for prolonged, severe headache, and nonopioid analgesic is often sufficient for transient neurological symptoms.

Clonidine 1 microg/kg is a safe and effective adjuvant to plain bupivacaine in spinal anesthesia in adolescents

BACKGROUND

Spinal anesthesia is increasingly used in adolescents. However, the anesthesia provided by bupivacaine alone may be too short for the planned surgery. The addition of clonidine 2 microg/kg to bupivacaine provides a prolonged anesthetic action but may be associated with hypotension. In the present study, we investigated the efficacy and safety of intrathecal clonidine 1 mug/kg in adjunction to bupivacaine in spinal anesthesia in adolescents.

METHODS

Eighty-three adolescents, 51 males, aged 10-15 yr, scheduled for orthopedic surgery were enrolled in this placebo-controlled, randomized study. Patients were given spinal anesthesia either with plain 0.5% isobaric bupivacaine 0.2-0.4 mg/kg or bupivacaine with clonidine 1 microg/kg. The duration of sensory block was the primary outcome measure.

RESULTS

Clonidine prolonged the duration of both the sensory and motor block. The time to regression of sensory block by two dermatomes was 136 (mean) (sd, 56) min in the adolescents with clonidine versus 107 min (sd, 42) in the controls (95% CI for diff: 5-53 min, P = 0.02). The time to full recovery of motor block was 251 min (sd, 79) in the adolescents with clonidine versus 181 min (sd, 59) in the controls (95% CI: 39-103 min, P = 0.001). Time to the first dose of rescue analgesia was longer in the adolescents with clonidine, 461 min (sd, 147) versus 330 min (sd, 138) in the controls (95% CI: 53-207 min, P = 0.01). There was no difference in the frequency of hypotension or bradycardia between the groups.

CONCLUSION

In adolescents, clonidine 1 microg/kg prolonged the duration of sensory block achieved with bupivacaine by 30 min and postoperative analgesia by 120 min without severe adverse events.

Ropivacaine spinal anesthesia in neonates: a dose range finding study

BACKGROUND

Our primary aim was to determine the minimum local anaesthetic dose (MLAD) defined as the median effective local anesthetic dose for spinal anesthesia in neonates. Secondary aims were to determine the dose-response curve for spinal anesthesia including the clinically relevant ED95 dose and to describe the duration of motor block following ropivacaine spinal anesthesia.

METHODS

Fifty neonates less than 55 weeks postmenstrual age (PMA) having inguinal hernia repair were enrolled. The study was performed in two stages. The MLAD dose of ropivacaine was determined by up-down sequential allocation. An expanded dose ranging study was then performed with dose escalation to doses predicted to fall in the ED50-95 range dose. Probit and logit analysis on all patients was used to compare ED50 with the value described by the Dixon-Massey method and to determine doses up to the ED95.

RESULTS

Fifty neonates with a mean PMA of 43 weeks and mean weight of 3.7 kg were enrolled. The motor block MLAD (95% confidence interval) determined by the Dixon-Massey method was 0.51 (0.38-0.64) mg x kg(-1). A logistic regression analysis of the results of all 50 patients confirmed the Dixon-Massey result. The ED50 (95% CI) was 0.50 (0.39-0.63) mg x kg(-1) with an estimated ED95 was 1.08 (0.70-1.67) mg x kg(-1). These values were confirmed by probit analysis. Overall the mean duration (95% confidence interval) of lower limb motor blockade was 60.0 min (51.5-68.5 min). The duration of anesthesia far exceeded surgical duration in all successful cases.

CONCLUSIONS

Ropivacaine is an effective agent for spinal anesthesia in neonates at a recommended dose of 1.08 mg.kg(-1). The motor block duration, however, is significantly shorter than equivalent agents and highly variable in duration.

High success rate and low incidence of headache and neurological symptoms with two spinal needle designs in children

BACKGROUND

In children, only a few trials have evaluated the use of spinal needles with special tip designs. In this study, we compared the success rate and incidence of post-dural puncture complaints of two small-gauge spinal needle designs used in children undergoing spinal anaesthesia (SA).

METHODS

Three hundred and three children aged 9 months to 17 years presenting for subumbilical surgery were randomly assigned to have a 26G Atraucan (n = 156) or 27G Whitacre (n = 147) spinal needle for SA. The number of attempts to obtain successful cerebrospinal fluid (CSF) return and the success rate of SA were recorded. The first week of recovery was recorded by a diary.

RESULTS

Both groups had a similar one-attempt success rate: 80% in the Atraucan group and 81% in the Whitacre group. Failure to obtain CSF occurred in one patient in the Atraucan group and in two patients in the Whitacre group. Paraesthesia was observed more commonly in the Whitacre group (10%) than in the Atraucan group (2%) (P = 0.004). The success rate of SA was 96%, with no differences between the two needles; one child was given general anaesthesia and 11 children (3%) a single dose of supplemental analgesia for the skin incision. Forty-one children (15%) developed a headache, 13 of which were classified as post-dural puncture headache (PDPH), seven cases (5%) in the Atraucan group and six (4%) in the Whitacre group; none of the children required a blood patch. Fifteen children (10%) in the Atraucan group and nine (7%) in the Whitacre group developed low back pain. Two children (1%) in the Atraucan group and four (3%) in the Whitacre group developed transient neurological symptoms (TNSs).

CONCLUSION

Both needles were associated with a high success rate and a low incidence of complaints.

Spinal anaesthesia in paediatric patients

PURPOSE OF REVIEW

Spinal anaesthesia has seldom been employed in paediatric patients. Its use has been suggested mainly in former preterm newborns and infants who are known to be exposed to high perioperative apnoea risk. There is currently some evidence that spinal anaesthesia could be considered as an equal alternative to general anaesthesia as it is in adults.

RECENT FINDINGS

New drugs and adjuvants recently introduced in clinical practice, more-detailed knowledge of spread anaesthetic modalities and larger databases, now available, could today make paediatric spinal anaesthesia a more suitable technique for many anaesthetists.

SUMMARY

We will review recent literature focusing the latest techniques, drugs, dosages, and complications in order to define the limits and advantages of employing spinal anaesthesia in all paediatric ages, in routine and emergency surgery.