Effects of ultrasound-guided thoracolumbar interfascial plane block combined with general anaesthesia versus general anaesthesia alone on emergence agitation in children with cerebral palsy undergoing selective posterior rhizotomy: protocol for a randomised controlled clinical trial

Trial design and setting

This randomised trial is underway at Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China. The protocol is reported in accordance with the Standard Protocol Items: Recommendations for Interventional Trials 2013 statement. The Consolidated Standards of Reporting Trials guidance will be followed when reporting the findings of the trial. The flow chart of the trial design and follow-up are shown in figure 1 and table 1.

Figure 1

Trial flow chart. FACES, Wong-Baker Faces Pain-rating Scale; ICU, intensive care unit; PAED, paediatric anaesthesia emergence delirium; SPR, selective posterior rhizotomy; TLIP, thoracolumbar interfascial plane.

Participant eligibility and consent

Patients diagnosed with cerebral palsy scheduled for SPR procedure at Dongzhimen Hospital, Beijing University of Chinese Medicine are screened and recruited for eligibility. Recruitment is finalised at the preoperative interview 1 day before surgery by a specialised researcher. Informed written consent is obtained from the legal guardian of the patients. Legal guardian consent form is presented in the online supplemental file.

Inclusion criteria

1. Children scheduled for SPR.

2. Age between 4 years and 12 years.

3. The American Society of Anesthesiologists I to II.

4. Written informed consent is obtained from the legal guardian of each patient.

Exclusion criteria

1. Severe spinal deformity.

2. Secondary or above lumbar surgery.

3. Puncture site infection.

4. Allergy to local anaesthetics.

5. Coagulation abnormalities.

6. Patients who are expected to be admitted to the intensive care unit after surgery.

7. Patients who are expected to return to the ward with a tracheal tube after surgery.

8. Patients with severe disorders of consciousness, mental system diseases (schizophrenia, mania, bipolar disorder, psychosis, etc) or cognitive dysfunction.

9. Refusal to participate in the study.

Intervention

TLIP group

The experimental group receives bilateral TLIP block. An ultrasound probe is positioned in the paraspinal sagittal position for the longitudinal scanning. The transverse process of the L3 vertebral body is located by the iliac image and the probe is rotated 90° to the short-axis plane to visualise the paraspinal thoracolumbar fascial space. The needle is inserted laterally between the longissimus and iliocostalis muscles using an in-plane access technique and 0.2% ropivacaine 0.5 mL/kg is injected after a bloodless retraction (figure 2). The maximum dose should not exceed 20 mL. A similar procedure is conducted on the contralateral side.

Figure 2

Ultrasound-guided thoracolumbar interfascial plane block. The interface between L and I muscles is marked with yellow dots. The red arrow shows the direction of needle insertion. I, iliocostalis muscle; L, longissmus muscle; M, multifidus muscle; SP, spinous process.

Outcomes

Participant timeline

For included participants, enrolment is performed 1 day before surgery and reconfirmed on the day of the procedure. Then random allocation is performed by a specific statistician before intervention. Patient recruitment began on 8 October 2023, and is expected to end on 30 December 2024.

Sample size

The minimal sample size was obtained based on a preliminary study with 10 patients, which indicated that the PAED Scores in the TLIP group and the control group were 10 and 8, respectively, with an SD of 1.8. Considering type I error of 0.05 and type II error of 0.1, we planned to recruit at least 25 patients per group to compensate for the loss in follow-up.

Allocation

This is a randomised, controlled trial. The random allocation sequence is conducted using a professional online tool for randomised clinical trials called “Randomizer” (https://www.randomizer.at/, Randomizer V.2.1.0, Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz). The treatment is concealed in sequentially numbered, opaque, sealed envelopes in the custody of a secretary who is not involved in the trial. Randomisation takes place after the participants’ final confirmation of enrolment.

Blinding

Participants are unaware of the distribution. The block is performed after general anaesthesia. Anaesthesiologists perform the nerve block and are responsible for intraoperative management. Investigators not involved in the nerve block and intraoperative management are designated for postoperative follow-up. In addition, trained anaesthesiologists designated not to perform the block objectively assess the clinical characteristics of the TLIP block.

Adverse event reporting and harms

Safety monitoring is always followed throughout the study. All adverse events associated with the study interventions will be documented in the study database and reported to the Adverse Event Registry System of Dongzhimen Hospital, Beijing University of Chinese Medicine as required within a specified time frame based on severity. The Clinical Trial Oversight Committee of Dongzhimen Hospital, Beijing University of Chinese Medicine is responsible for deciding whether to stop this study on a case-by-case basis.

Clinically relevant adverse events associated with treatment will be taken into account: injection site infection, pneumothorax and local anaesthetic toxicity over the trial period. If an adverse event occurs, the researcher should explain it to the participant’s legal guardian and require the participant’s legal guardian to truthfully report any changes in his/her children’s condition after treatment. For adverse events occurring during the study, the symptoms, extent, time of occurrence, duration, treatment and experience should be recorded on thecase report form (CRF). If a serious adverse event occurs in the study, the project leader must adopt immediate actions to ensure the safety of the subjects. The investigator should also inform the ethics committee, the data monitoring committee and the relevant regulatory bodies of the expectedness, severity, gravity and causality, as necessary. When a severe adverse incident happens in a clinical study that warrants urgent unblinding, the study should be unblinded by the project leader, the investigator and the clinical supervisor.

Data collection and management

Preoperative, intraoperative and postoperative follow-up data are gathered and stored properly as study material. All collected data are enrolled in a CRF, designed for each included patient. All data are input into the electronic case report file and any traces of entries, modifications, deletions, and so on, will be kept in a log showing who made the changes and when. Paper-based data are entered into the electronic case report file by two research assistants using duplicate entries. Electronic data are copied and the copied electronic data are kept by others. The researcher double-checks the data against the CRF to confirm the quality of the data. A particular biostatistician finishes the screening and randomisation of the study data.

Participant retention and withdrawal

Participants are followed up by the clinical coordinator of the study. All participants have the right to withdraw from the study at any stage. If a patient determines to do so, this will not jeopardise the relationship with the investigator and they will proceed to obtain the best possible therapy. Once a patient has withdrawn from the study, the experimenter will ask if they agree to complete follow-up and if they are willing to accept being used with their data. If a participant is comfortable giving this information, any data already gathered by that participant will be analysed independently before unblinding, and finally interpreted in a separate section of the results of this trial.

Statistical methods

The statistical analysis will be carried out with the statistical software SPSS V.25 (IBM, Armonk, New York). The distribution of the data will be evaluated using the Kolmogorov-Smirnov test. Normally distributed continuous variables will be shown as mean (SD), and those without normally distributed data will be performed as median (IQR). Categorical variables will be shown as numbers (percentages). Between-group differences will be assessed by performing the independent Student’s t-test for continuous normal variables, while non-parametrical data will be compared by the Mann-Whitney U test, as appropriate. A χ² test or Fisher’s exact test will be conducted for categorical variables. Repeated-measures analysis of variance will be used within groups for data with normal distribution. For variables with non-normal distribution, the Friedman test will be carried out for repeated measures. Subgroup analyses are performed based on age. Any changes to the statistical analysis programme will be noted in the next publications. Bonferroni correction will be performed for multiple tests. A value of p<0.05 will be regarded as statistically significant.

Patient and public involvement

None.