Neurolytic celiac plexus block for visceral abdominal malignancy: Is prior diagnostic block warranted?

Neurolytic celiac plexus block is a recognised treatment for visceral abdominal pain due to malignancy. The need for a diagnostic celiac plexus block prior to neurolytic blockade is of questionable value, as it may not predict a positive response and may incorrectly predict it lack of response. Our objective is to evaluate the efficacy of diagnostic celiac plexus block. The records of 59 patients treated with celiac plexus block during 1994-2000 were. retrospectively reviewed. Diagnostic block was performed on 32 patients prior to the decision for subsequent neurolytic block (Group 1). Another 27 patients were directly treated with a neurolytic celiac plexus block (Group 2). Response of Group I to diagnostic and neurolytic blocks was compared. Data from Group 2 was used to project the response of Group I should those patients with negative response to diagnostic block proceeded to neurolytic block. A two-by-two table was then constructed. The diagnostic celiac plexus block predicted a positive response with a sensitivity of 93% and a specificity of 37%. The positive predictive value was 85% and the negative predictive value was 58%. The estimated "number needed to test" before a "true" nonrespondent to lytic block to be detected was 16.7. Therefore, a positive response to diagnostic block correlates positively, with neurolytic celiac plexus block for abdominal visceral pain due to malignancy. However, diagnostic block is a poor predictor when the response is negative. Hence, its clinical role is questionable and may not be warranted for patients with terminal malignancy.