Risk Factors for and Prediction of a Difficult Neuraxial Block: A Cohort Study of 73,579 Patients from the Danish Anaesthesia Database.

BACKGROUND: A difficult neuraxial block (DNB) may be associated with complications. The aims of this study were to estimate the prevalence of DNB, assess patient-related and organizational factors associated with DNB, and evaluate the diagnostic accuracy of an accumulated risk score for predicting DNB. METHODS: A consecutive cohort of 73,579 patients was retrieved. A predefined DNB score and information on patient-related and organizational factors were included in the analyses. Logistic regression analysis was performed. We evaluated the diagnostic accuracy of an accumulated weighted point score of the patient-related risk factors of DNB. RESULTS: The prevalence of DNB and abandoned neuraxial block was 3.9 (95% confidence interval [95% CI], 3.7-4.0) and 0.2 (95% CI, 0.16-0.22), respectively. Body mass index of 35 or higher and previous DNB were associated with DNB, with 3.23 (95% CI, 2.87-3.65) and 2.00 (95% CI, 1.33-3.00), respectively. However, the remaining patient-related covariates were associated with DNB with substantial lower odds ratios. The diagnostic accuracy of an accumulated sum score demonstrated an area under the curve of 0.62 (95% CI, 0.61-0.64), a positive predictive value of 5%, and a positive likelihood ratio of 1.4. CONCLUSIONS: Despite of strong statistical association between DNB and the tested risk factors, the low odds ratios and estimates of the diagnostic test indicate that the clinical impact using an accumulated risk sum score is limited.

There is room for improvement in the prevention and treatment of headache after lumbar puncture.

INTRODUCTION: The incidence of post dural puncture headache (PDPH) after lumbar puncture (LP) can be reduced from 36% to 0-9% by use of an atraumatic needle size 24 gauge (G)/0.56 mm rather than a traumatic needle size 22 G/0.7 mm. The evidence supporting some of the prophylactic and therapeutically treatments of PDPH is sparse. The objective of this study was to clarify which needles doctors at neurological departments in Denmark use for LP and how they treat and prevent PDPH. MATERIAL AND METHODS: The present study is a questionnaire survey among doctors employed at the 13 neurological departments in Denmark. RESULTS: A total of 161 (51%) returned the questionnaire. As for needle size, 78% stated that they used needle size 22 G, 5% used 21 G, 13% used 20 G and 3% used 18 G. Overall, 74% used traumatic needles, while 18% were unaware of the needle type used. Prophylactic bed rest was prescribed by 44%. Prescribed treatments of PDPH were caffeine, analgesics/fluid therapy and epidural blood patch (EBP). Surprisingly many of the doctors used relatively thick and/or traumatic needles although PDPH is significantly reduced when smaller atraumatic needles are used. 90% prescribed fluid therapy, but the role of fluid therapy as well as that of analgesics in the treatment of PDPH remains uncertain. There was no difference in the incidence of PDPH using prophylactic bed rest versus early mobilization. Caffeine can reduce the number of patients with persisting PDPH, while EBP is the most effective treatment for PDPH. CONCLUSION: Atraumatic needles for LP have not become standard in Danish neurological departments. Knowledge about the treatment and prevention of PDPH seems insufficient.