Pudendal nerve blocks are a pre-requisite to forceps delivery without regional anaesthesia. Their efficacy is dependent on introducing local anaesthetic in close proximity to the pudendal nerve and allowing sufficient time for its onset of action. An audit of 57 obstetricians evaluated their clinical technique against standards using both a questionnaire and adapted model pelvis. The majority of participants were unable to describe correctly the point of infiltration and were unaware of the lag time required to effect adequate analgesia. We identify a deficiency in training and describe a method by which training can be facilitated and assessed.

Aim: To evaluate the e¡ect of 0.3 M potassium chloride on cystometric parameters by comparing it with normal saline as a ¢lling solution in women with overactive bladder (OAB). Patients and Methods: Twenty-three women with signi¢cant OAB symptoms underwent consecutive cystometrograms (CMGs) using 0.9% normal saline (NS) and 0.3 M potassium chloride (KCl), the order of which was randomized for each patient. Individual CMGs were performed by separate investigators and both patients and investigators were blinded to the order in which each solution was given and to the results of the other CMG. Results: Regardless of the nature of the ¢lling solution, the order in which the CMGs were performed had little in£uence on either ¢rst desire to void (FDV, mean 83.5 ml vs. 117.8 ml for ¢rst and second CMGs respectively, P ¼ 0.10) or on maximum cystometric capacity (Cmax, mean 265.0 ml vs. 264.4 ml, P ¼ 0.98). KCl produced a signi¢cant (24%) reduction in mean Cmax compared to NS (mean 228.6 ml vs. 300.8 ml, P ¼ 0.001), irrespective of the order of infusion. Conclusion: This comparative study using 0.3 M KCl versus NS as ¢lling solutions suggests that intravesical potassium may not simply act on urothelial sensory nerve endings; it may also stimulate detrusor muscle contraction. These ¢ndings may in£uence the interpretation of the potassium sensitivity test in patients with OAB symptoms, particularly in those suspected of having interstitial cystitis.

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