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. 2017 Apr 7;2017(4):CD010807. doi: 10.1002/14651858.CD010807.pub2

Crock 2014.

Methods

  • Design: 4‐period cross‐over, blinded

  • Country: Australia

  • Multisite: no

  • International: no

  • Needle tip used: 22 G or 25 G standard cutting point

  • Needle diameter used: 22 G or 25 G

  • Number of attempts: single needle insertion 94%

  • Procedure: leukaemia treatment

  • CSF collection and methotrexate intrathecal (except in 4 procedures)

  • Site of the puncture: not stated

  • Training level of those who administered the puncture: experienced doctor

  • Median or paramedian technique: not stated
Participants 1. 133 children having LP as part of their standard treatment protocol for leukaemia, recruited during visits to the Day Surgery Unit of the Royal Children’s Hospital. Aged 4 to 15 years at the time of first procedure.
Exclusion criteria: excluded if they had insufficient LPs remaining in their planned treatment, had significant coexisting medical problems causing headache or were routinely using 25 G needles at parental request, or if there were significant social or communication problems.
3. 40 were excluded for meeting exclusion criteria

  • Insufficient LPs remaining (24)

  • Communication problems (10)

  • Using 25 G for all procedures (2)

  • Continuous headache (1)

  • Family declined to take part (3)


4. 93 were allocated to a random sequence of 4 LPs, 2 with 22 G (A) and 2 with 25 G (B), and completed 341 LPs

  • Random sequence of 4 LPs: 2 with 22 G and 2 with 25 G

  • Analysis grouped interventions with 22 G and 25 G


2. No randomized patients were excluded
3. 18 patients lost to follow‐up: 2 children had their last LP after their 16th birthday (excluded). 16 did not complete all 4 procedures for reasons such as moving interstate or finishing their treatment protocol, giving a total of 341 procedures (167 with the 22 G and 174 with the 25 G needle)
4. Main characteristics of patients (not specifying groups):

  • Age: median 6.5 years (IQR 4.6 to 9.7)

  • Percentage/number of men: 63 (68%)

  • Time between procedures (median, IQR): 49 (7 to 336)
Interventions

  1. 25 G (intervention): under general anaesthesia, lumbar puncture using 25 G for collection of CSF and then administered methotrexate intrathecal. LP position not stated. The needle was inserted with the orientation of the bevel parallel to the long axis of the dural fibres.

  2. 22 G (control): under general anaesthesia, lumbar puncture using 22 G for collection of CSF and then administered methotrexate intrathecal. LP position not stated. The needle was inserted with the orientation of the bevel parallel to the long axis of the dural fibres.
Outcomes Primary outcomes:

  1. The presence of LP headache, defined as occurring within 7 days after the procedure, being worse within 15 minutes of standing up and improving within 30 minutes of lying down


Secondary outcomes: assessed by a 1‐page questionnaire and telephone interview on days 1, 3 and 7 following the procedure

  1. Presence of any headache within 7 days

  2. CSF collection time

  3. Total procedure time

  4. Number of failed needle attempts

  5. Impact of headache on the family and the child
Notes

  1. Trial registration: Australia and New Zealand CTR 12605000052639

  2. Funder: Perpetual philanthropy

  3. Role of funder: Funding for this project. "No person associated with the funding body had any role or involvement in any aspect of the study at any time" (page 206)

  4. A priori sample size estimation: no

  5. Conducted: May 2005 to May 2007

  6. Declared conflicts of interest: yes (page 206)
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Low risk Quote: "The treatment allocation was computer‐generated by an independent statistician." (page 204)
Allocation concealment (selection bias) Low risk Quote: "Patients were allocated a sequential study number which corresponded to a large envelope containing four smaller sealed envelopes, labelled a, b, c and d, containing details of the needle sizes to be used for four procedures" (page 204)
Blinding of participants (performance bias) Low risk Quote: "All LPs were performed under general anaesthesia by the same experienced doctor (CC) who was given the relevant sealed envelope immediately before the procedure. This doctor was not involved in data collection after the procedure. All other staff and study participants were blinded to the needle gauge." (page 204)
Blinding of outcome assessment (detection bias) 
 All outcomes Low risk Quote: "A study researcher blinded to the needle size recorded the time from first needle insertion to successful commencement of CSF collection and the time required for collection of 22 drops of CSF (approximately 1 mL) (…) Following each procedure, parents were given a one‐page questionnaire to take home which asked them to record details of any headache in the child on days 1, 3 and 7 following the procedure (…) A researcher also phoned families on days 1, 3 and 7 after each procedure to ensure the data were recorded, and confirm the nature of any headache." (page 204)
Incomplete outcome data (attrition bias) 
 All outcomes Low risk 8.3% (31 out of 372 procedures) were lost to follow‐up
Selective reporting (reporting bias) High risk Adverse events, additional to PDPH, were not reported
Other bias Low risk No other biases were identified