Epidural blood patch is considered the gold standard for treatment. Typically, 10 to 20 mL of autologous blood obtained aseptically by venipuncture is injected into the epidural space. Further CSF leakage is halted by either mass efect or coagulation. Relief is almost always immediate, and complications are uncommon. The initial success rate of an epidural blood patch ranges from 61 to 73 percent (Paech, 2011). Performing a "prophylactic" blood patch is debatable and is thought not to be as efective as if performed after the headache develops (Scavone, 2004, 2015).
If a headache does not have the pathognomonic postural characteristics or persists despite treatment with a blood patch, other diagnoses are considered. Chisholm and Campbell (2001) described a case of superior sagittal sinus thrombosis that manifested as a postdural headache. Smarkusky and colleagues (2006) described pneumocephalus, which caused immediate cephalgia. Finally, intracranial and intraspinal subarachnoid hematomas have developed after spinal analgesia (Dawley, 2009; Liu, 2008).
Convulsions. In rare instances, postdural puncture cephalgia is associated with temporary blindness and convulsions. Shearer and associates (1995) described eight such cases associated with 19,000 regional analgesic procedures done at Parkland Hospital. It is presumed that these too are caused by CSF hypotension. Immediate treatment of seizures and a blood patch were usually efective in these cases.
Bladder Dysfunction. With neuraxial analgesia, bladder sensa tion is likely to be obtunded and bladder emptying impaired for several hours after delivery. As a consequence, bladder distention is a frequent postpartum complication, especially if appreciable volumes of intravenous luid are given. Millet and colleagues (2012) randomized 146 women with neuraxial analgesia to either intermittent or continuous bladder catheterizations and found that the intermittent method was associated with signiicantly higher rates of bacteriuria. That said, we do not recommend routine postpartum use of indwelling catheters following uncomplicated vaginal delivery.
Arachnoiditis and Meningitis. Local anesthetics are no longer preserved in alcohol, formalin, or other toxic solutes,
TABLE 25-6. Absolute Contraindications to Neuraxial Analgesia
Skin infection over site of needle placement and disposable equipment is usually used. hese practices, coupled with aseptic technique, have made meningitis and arachnoiditis rare (Centers for Disease Control and Prevention, 2010).
Contraindications to Neuraxial AnalgeSia
Shown in Table 25-6 are absolute contraindications. Obstetrical complications that are associated with maternal hypovolemia and hypotension-for example, severe hemorrhage-are contraindications (Kennedy, 1968).
Disorders of coagulation and defective hemostasis also preclude neuraxial analgesia use. Although no randomized studies guide the management of anticoagulation at the time of delivery, consensus opinion suggests that women given subcutaneous unfractionated heparin or low-molecular-weight heparin should be instructed to stop therapy when labor begins (Krivak, 2007). Subarachnoid puncture is also contraindicated if cellulitis involves the planned needle entry site. Many consider neurological disorders to be a contraindication, if for no other reason than that exacerbation of the neurological disease might be erroneously attributed to the anesthetic agent. Other maternal conditions, such as aortic stenosis or pulmonary hypertension, are also relative contraindications (Chap. 49, p.i948).