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Treating Postdural Puncture Headache With Hydroxyethyl Starch Patch: A Novel Method.

To the Editor: Postdural puncture headache (PDPH) is a debilitating complication of dural puncture during conduct of neuraxial analgesia. We wish to report about the successful treatment of a PDPH patient with epidural patch of hydroxylethyl starch (HES). A 65-year-old American Society of Anesthesiologists grade I female patient posted for open hysterectomy was planned to be administered general anesthesia along with epidural catheter placement. During the first attempt at placing the epidural catheter, dura mater was accidentally punctured at L1–L2 interspace, causing loss of cerebrospinal fluid (CSF). Later, the catheter was resited at L2–L3 interspace. The patient had an uneventful anesthetic and surgical course. The epidural catheter was utilized for providing satisfactory analgesia postoperatively. Next morning, the patient started complaining of severe throbbing frontal headache with photophobia, which worsened on sitting or head elevation. Diagnosed as PDPH, the patient was advised strict bed rest, liberal intravenous fluids, and analgesics. Till the third day, despite adopting conservative measures, the severe headache persisted. Although conservative treatments like bed rest, hydration, and caffeine are advocated, an epidural blood patch (EBP) remains the gold standard in resistant cases of PDPH.1 Because the headache was unrelenting, we offered to administer EBP. The patient however refused additional needle punctures and so we could not collect the autologous blood, thereby ruling out an EBP. As epidural catheter was in situ, it was decided to be utilized for therapeutic intervention. The local anesthetic infusion was stopped, and the catheter was flushed and cleared with saline. Six-hour waiting period after the last dose of epidural local anesthetic was undertaken to dissipate its effect. After obtaining consent from the patient and confirming block regression and negative CSF aspiration, we injected 20 mL of sterile 6% HES (Voluven, Fresenius Kabi, India) through the epidural catheter. The headache was relieved immediately after a single bolus, and there was no recurrence thereafter. The patient was followed up daily till she was discharged from the hospital on the fifth postoperative day and then weekly for a month telephonically for any neurological symptoms, backache or headache, which were negated. PDPH is a distressing and disabling complication of dural puncture, and its severity bears a direct relation to the size of needle used. Due to the larger diameter of the epidural needle used, the incidence of PDPH was expectantly high (75%–84%).2 EBP with autologous blood is the most effective treatment for PDPH, which presumably raises the CSF pressure, creating a tamponading effect.3 Alternately, it is believed to stimulate inflammatory reaction in the dura sealing the dural rent.4 Although effective, EBP has its complications. Back pain, neck stiffness, and paresthesias are transient, but aseptic meningeal irritation, radiculopathy, and lumbovertebral syndrome may persist longer. Epidural blood can cause subarachnoid edema, arachnoiditis, or spinal hematoma. Systemic or localized sepsis and leukemia prevent the use of autologous blood for EBP. Injecting blood through the epidural catheter invariably blocks it with clots so for a repeat blood patch, and epidural space needs to be relocated at other levels, which is unpleasant especially in patients with severe headache. The quest for other options had prompted the use of nonautologous blood substitutes5–7 or commercially available fibrin glue.8 Epidural saline infusions too have been tried albeit with low efficacy.9 Although occasional reports of successful outcomes with these alternatives of epidural injectates exist, data from controlled trials are limited. Among plasma expanders, dextran and gelatin are reputed to cause antigenicity. Fibrin glue is relatively expensive and cannot be injected through the epidural catheter. Considering the previous usage of plasma expanders, HES appeared to be an ideal candidate. In addition to lesser antigenicity, higher molecular weight allows it to remain inside the epidural space longer, providing sustained relief. It could be freely injected through the epidural catheter. Unlike blood, it does not clot, so the same catheter can be reused if a repeat dose is needed. This alleviates the need to locate the epidural space at a different spinal level. Although the exact Letters to the Editor e619