Half Life Blood Patch
Harrington and Miguel Angel Reina INTRODUCTIONPostural headaches following interventions that disrupt meningeal integrity are most commonly labeled postdural puncture headaches (PDPHs). This terminology has been officially adopted in the International Classification of Headache Disorders and is used in this section. However, use of the word postdural has been criticized as confusing and probably inaccurate, resulting in the proposal of an alternate term, meningeal puncture headache (MPH), which readers may increasingly encounter. It is also important to acknowledge that references to “dural puncture” throughout the medical literature actually describe puncture of the dura-arachnoid and are more correctly termed and thought of as “meningeal puncture.” Regardless of terminology, the PDPH is well known to the many clinicians whose practice includes procedures that access the subarachnoid space.Yet, our understanding of this serious complication remains surprisingly incomplete.
This section summarizes the current state of knowledge regarding this familiar iatrogenic problem as well as the closely related topics of accidental, or unintentional, dural puncture (ADP or UDP, respectively), and the epidural blood patch (EBP). HISTORY AND CURRENT RELEVANCEAs one of the earliest recognized complications of regional anesthesia, PDPH has a long and colorful history. August Bier noted this adverse effect in the first patient to undergo successful spinal anesthesia on August 16, 1898 ( Figure 1). Bier observed: “Two hours after the operation his back and left leg became painful and the patient vomited and complained of severe headache. The pain and vomiting soon ceased, but headache was still present the next day” (italics added). The following week, Bier and his assistant, Dr.
August Hildebrandt, performed experiments with cocainization of the spinal cord on themselves. In a description of PDPH scarcely improved on in an intervening century, Bier later reported firsthand his experience in the days to follow: “I had a feeling of very strong pressure on my skull and became rather dizzy when I stood up rapidly from my chair. All these symptoms vanished at once when I lay down flat, but returned when I stood up. I was forced to take to bed and remained there for nine days, because all the manifestations recurred as soon as I got up. The symptoms finally resolved nine days after the lumbar puncture.” In medical history, few complications have come to be associated as closely to a specific technique as PDPH with spinal anesthesia. Employing the methods of the early 20th century, spinal anesthesia was frequently followed by severe and prolonged headache, casting a long shadow over the development and acceptance of this modality. Investigations into the cause of these troubling symptoms eventually led to the conclusion that they were due to persistent cerebrospinal fluid (CSF) loss through the rent created in the meninges.
The most notable successful efforts to minimize the loss of CSF were through the use of smaller-gauge and “noncutting” needles (as convincingly demonstrated in the 1950s by Vandam and Dripps and Hart and Whitacre, respectively). Despite these significant advances in prevention, PDPH remained a frustratingly common occurrence. August Bier.The extensive search for effective treatments for PDPH dates to Bier’s time.
Yet, efforts through the first half of the 20th century, while often intensive and creative, were questionably worthwhile. In a monograph intended to be a comprehensive review of PDPH from the 1890s through 1960, Dr. Wallace Tourette and colleagues cited dozens of separate and far-ranging treatment recommendations, including such interventions as intravenous ethanol, x-rays to the skull, sympathetic blocks, and manipulation of the spine. Unfortunately, prior to the introduction of the EBP there were no treatment measures that could be described as significant improvements over the simple passage of time. In his 1955 textbook, Complications of Regional Anesthesia, Dr. Moore described in detail a full 3-day treatment protocol for PDPH. He concluded by noting that 3 days was the usual duration of untreated mild-to-moderate headaches, but that, “Nevertheless, the patient feels an attempt to help his problem is being made.” The EBP, a startlingly unique medical procedure, proved to be the major breakthrough in the treatment of PDPH.
The concept of using autologous blood to “patch” a hole in the meninges was introduced in late 1960 by Dr. James Gormley, a general surgeon.Yet, Gormley’s brief report went largely unnoticed for nearly a decade because, to the practitioners of the day, an iatrogenic epidural hematoma raised serious concerns of scarring, infection, and nerve damage. The procedure was only later popularized in anesthesiology circles, and performed as a true epidural injection, largely through the work of Drs. Anthony DiGiovanni and Burdett Dunbar. The EBP procedure was further refined through the 1970s as the volume of blood commonly utilized increased to 20 mL. Today, the EBP is nearly universally employed as the cornerstone for treatment for severe PDPH.
Postdural puncture headache remains a prominent clinical concern to the present day. Largely due to modifications in practice that followed the identification of risk factors, rates of PDPH following spinal anesthesia have steadily declined, from an incidence exceeding 50% in Bier’s time, to around 10% in the 1950s, until currently a rate of 1% or less can be reasonably expected. However, as perhaps the highest-risk group, an unfortunate 1.7% of obstetric patients continue to experience PDPH after spinal anesthesia using 27-gauge Whitacre needles.
Intending to avoid meningeal puncture, epidural techniques are an attractive alternative to spinal anesthesia.Yet, occasional ADP, with either the needle or the catheter, is unavoidable (and may be unrecognized at the time in over 25% of patients who eventually develop PDPH). In nonobstetric situations (eg, interlaminar epidural steroid injections), the rate of ADP should be less than 0.5%. However, ADP is of greatest concern in the obstetric anesthesia setting, where the incidence of this adverse event is around 1.5%. Over half of all patients who experience ADP with epidural needles will eventually develop headache symptoms, with many studies in obstetric populations reporting PDPH rates of 75% or greater. Of further concern, ADP in parturients has also been noted to be associated with chronic headache and back pain that is reduced, but not entirely eliminated, by EBP. In addition to anesthesia interventions, PDPH remains a too-common iatrogenic complication following myelography and diagnostic/therapeutic lumbar puncture (LP).
In these situations, rates of MPH of around 10% are still commonly cited as practitioners often continue to use large-gauge Quincke needles—considered necessary due to the viscosity of contrast material and to facilitate the timely collection of CSF. Consequently, there is evidence to suggest that the majority of instances of PDPH now have a non-anesthesia-related origin. OnsetOnset of symptoms is generally delayed, with headache usually beginning 12–48 hours and rarely more than 5 days following meningeal puncture.
In their landmark observational study, Vandam and Dripps reported onset of headache symptoms within 3 days of spinal anesthesia in 84.8% of patients for whom such data were available. More recently, Lybecker and colleagues performed a detailed analysis of 75 consecutive patients with PDPH following spinal anesthesia (primarily using 25-gauge cutting-point needles). While none of their patients noted the onset of symptoms during the first hour following meningeal puncture, 65% experienced symptoms within 24 hours and 92% within 48 hours. An onset of symptoms within 1 hour of neuraxial procedures is suspicious for pneumocephalus, especially in the setting of an epidural loss of-resistance technique using air.
Occasional reports of unusually delayed onset of PDPH highlight the importance of seeking a history of central neuraxial instrumentation whenever positional headaches are evaluated. PresentationThe cardinal feature of PDPH is its postural nature, with headache symptoms worsening in the upright position and relieved, or at least improved, with recumbency. The International Headache Society (IHS) diagnostic criteria further describe this positional quality as worsening within 15 minutes of sitting or standing and improving within 15 minutes after lying. Headache is always bilateral, with a distribution that is frontal (25%), occipital (27%), or both (45%). Headaches are typically described as “dull/aching,” “throbbing,” or “pressure type.” The severity of headache symptoms, a feature with important ramifications for treatment, varies considerably among patients. Although there is no universally accepted severity scale, one practical approach is to have patients simply rate their headache intensity using a 10-point analog scale, with 1–3 classified as “mild,” 4–6 “moderate,” and 7–10 “severe.” Lybecker et al further categorized patients according to restriction in physical activity, degree of confinement to bed, and presence of associated symptoms. Using this classification system, they prospectively determined that 11% of their PDPH cases after spinal anesthesia were mild, 23% moderate, and 67% severe.
Associated SymptomsThe IHS criteria for PDPH require that headache be accompanied by at least one of the following symptoms: neck stiffness, tinnitus, hypoacusia, photophobia, and nausea. However, these criteria may need to be revisited as many patients (29% in one recent study) have been noted to suffer from PDPH in the absence of any symptoms apart from the headache itself. It can be said that the more severe the headache, the more likely it is to be accompanied by associated symptoms.
The most common associated symptom is nausea, which may be reported by a majority of patients (especially if questioned specifically) and can lead to vomiting. Pain and stiffness in the neck and shoulders are also common and are seen in nearly half of all patients experiencing PDPH. Uncommonly, patients may experience auditory or visual symptoms, and the risk for either appears to be directly related to needle size. In Vandam and Dripps’s large observational study of PDPH, auditory and visual symptoms were each seen in 0.4% of patients.
Auditory symptoms include hearing loss, tinnitus, and even hyperacusis, and can be unilateral. It is interesting to note that subclinical hearing loss, especially in the lower frequencies, has been found to be common following spinal anesthesia, even in the absence of PDPH.
Closely associated with an auditory function, vestibular disturbances (dizziness or vertigo) may also occur. Visual problems include blurred vision, difficulties with accommodation, mild photophobia, and diplopia. In contrast to headache complaints, which are consistently bilateral, nearly 80% of episodes of diplopia secondary to meningeal puncture involve unilateral cranial nerve palsies. RISK FACTORSRisk factors for PDPH can be broadly categorized into patient characteristics and procedural details. Patient CharacteristicsThe patient characteristic having the greatest impact on risk of PDPH is age. Uncommonly reported in children less than 10 years of age, PDPH has a peak incidence in the teens and early 20s. The incidence then declines over time, becoming much less frequent in patients over 50 years of age.
Gender is also a significant risk factor, with nonpregnant females having approximately twice the risk for PDPH when compared with age-matched male subjects. While the etiology behind this gender difference has not been convincingly elucidated, a number of physiological, anatomical, social, perceptual, and behavioral explanations have been proposed. Pregnancy has traditionally been regarded as a risk factor for PDPH, but this consideration largely reflects a young female cohort as well as the high incidence of ADP in the gravid population.
Although controversial, pushing during the second stage of labor, thought to promote the loss of CSF through a hole in the meninges, has been reported to influence the risk of PDPH following ADP. Angle and colleagues noted that the cumulative duration of bearing down correlated with the risk of developing PDPH in patients who had experienced ADP.41 They also found that patients who avoided pushing altogether (proceeded to cesarean delivery prior to reaching second-stage labor) had a much lower incidence of PDPH (10%) than those who pushed (74%). Furthermore, they noted a marked difference in the requirement for EBP to treat PDPH between those who pushed and those who did not (81% vs.
Body mass index (BMI) appears to be a mixed-risk factor. Morbid obesity presents obvious technical difficulties for central neuraxial procedures, increasing the likelihood of multiple needle passes and ADP. Yet, low BMI has been reported to be an independent risk factor for PDPH, and high BMI (ie, obesity) may actually decrease risk, possibly secondary to a beneficial effect of increased intra-abdominal pressure.
Recently, a retrospective analysis reported cigarette smoking to be associated with a lower risk of PDPH. It can be hoped that this observation will promote further insights into the mechanism of PDPH symptoms and pharmacologic treatment options. Postdural puncture headaches appear to have an interesting association with other headaches. Patients who report having had a headache within the week prior to LP have been observed to have a higher incidence of PDPH. On further analysis, only those with chronic bilateral tension-type headaches were found to be at increased risk. A history of unilateral headache or migraine has not been linked to an increased risk of PDPH. Menstrual cycle, a factor in migraine headaches did not influence the rate of PDPH in one small pilot study.
Patients with a history of previous PDPH, particularly women, appear to have an increased risk for new PDPH after spinal anesthesia. With epidural procedures, patients with a history of ADP have been shown to be at slightly increased risk for another ADP (and subsequent PDPH). Procedural DetailsNeedle size and tip design are the most important procedural factors related to PDPH. Needle size is directly related to the risk of PDPH. Meningeal puncture with larger needles is associated with a higher incidence of PDPH, more severe headaches, more associated symptoms, a longer duration of symptoms, and a greater need for definitive treatment measures. Needle tip design is also a major influence, with “noncutting” needles clearly associated with a reduced incidence of PDPH when compared with “cutting” (usually Quincke) needles of the same gauge ( Figure 7).
In general, noncutting needles have an opening set back from a tapered (“pencil-point”) tip and include the Whitacre, Sprotte, European, Pencan, and Gertie Marx needles. Adding to this somewhat-confusing terminology, noncutting needles are sometimes still incorrectly referred to as “atraumatic” needles, this despite being shown with electron microscopy to produce a more traumatic rent in the dura than cutting needles (perhaps resulting in a better inflammatory healing response). The influence of needle size on risk of PDPH appears to be greatest for cutting needles (in other words, the reduction seen in the incidence of PDPH between 22- and 26-gauge sizes is greater for cutting than noncutting needles). Insertion of cutting needles with the bevel parallel to the long axis of the spine significantly reduces the incidence of PDPH.
This observation was for many years attributed to spreading rather than cutting of longitudinally oriented dural fibers. However, scanning electron microscopy revealed the dura to be made of many layers of concentrically directed fibers, and the importance of needle bevel insertion is now thought to be due to longitudinal tension on the meninges, particularly in the upright position, and its influence on CSF leakage through holes having differing orientations.
Spinal needles of different manufacturers with same external diameter. A: Whitacre type. B: Spinal type. C: Sprotte type. D, E: Quincke type. Scanning electron microscopy. Magnification ×40.
(Reproduced with permission from Reina MA: Atlas of Functional Anatomy for Regional Anesthesia and Pain Medicine. Heidelberg: Springer; 2015.). Not surprisingly, the experience/comfort/skill of the operator appear to be significant factors in the development of PDPH. A larger number of meningeal punctures, frequently associated with inexperience, have been shown to increase the rate of PDPH. De Almeida et al noted higher rates of PDPH when LP was performed by inexperienced providers.
Higher rates of ADP have been consistently reported when epidural procedures are performed by residents. The risk of ADP also appears to be higher for procedures done at night, strongly suggesting a significant contribution of operator fatigue. A number of procedural details do not appear to influence the rate of development of PDPH, including patient position at the time of meningeal puncture, “bloody tap” during spinal anesthesia, addition of opiates to the spinal block, and volume of CSF removed (for diagnostic purposes). PREVENTIONAlthough prophylaxis is most simply thought of as preventing any symptoms of PDPH, in the clinical context this issue is deceptively complex.
It is important to appreciate that significant “prevention” may encompass a number of other endpoints, such as a reduced incidence of severe PDPH, a shorter duration of symptoms, or decreased need for EBP. Unfortunately, despite the clear relevance of this issue, the overall quality of evidence for preventive measures is generally weak. General MeasuresAs with all regional techniques, appropriate patient selection is crucial in minimizing complications.
As age is a major risk factor, indications for spinal anesthesia should be weighed against the risks of PDPH in patients under 40 years of age unless the benefits are sufficiently compelling (such as in the obstetric population). Practitioners (and patients alike) may also wish to carefully consider central neuraxial techniques in those with a previous history of ADP or PDPH (particularly females). Other patient-related factors (eg, obesity) should be considered on a case-by-case basis, weighing the risks of PDPH with the benefits of regional anesthesia. While only recently utilized for neuraxial techniques, the use of ultrasound for regional anesthesia holds some promise in reducing the risk of PDPH. Ultrasound can decrease the number of needle passes required for regional procedures and has been shown to accurately predict the depth of the epidural space. Further study is ongoing to define this potential for ultrasound to reduce the incidence of ADP and PDPH. While multiple pharmacologic agents have been tried and investigated for prevention of PDPH, the efficacy of various strategies remains unclear.
As an example, intravenous dexamethasone has recently been shown in randomized controlled trials (RCTs) to decrease, but not influence, and even increase the risk of PDPH.A recent review of drug therapy for preventing PDPH identified only 10 RCTs for review. The primary outcome, a reduction in the number of patients affected by PDPH of any severity, was affected by administration of intrathecal morphine sulfate or fentanyl, oral caffeine, rectal indomethacin, or intravenous dexamethasone. Although a reduction in the incidence of PDPH was seen with epidurally administered morphine (relative risk RR 0.25), intravenous cosyntropin (RR 0.49), and intravenous aminophylline (RR 0.21 at 48 hours), the benefit of each was only demonstrated in a single study. Regardless, despite the paucity of evidence, pharmacologic measures—particularly caffeine—continue to be widely used in hopes of decreasing the incidence or severity of PDPH following meningeal puncture. However, no pharmacologic prophylaxis for PDPH has been independently confirmed, and various regimens used have been associated with adverse events.A recent survey of US anesthesiologists reported that bed rest and aggressive oral and intravenous hydration continue to be suggested by a sizable majority as prophylactic measures against PDPH. However, a systematic review of the literature regarding bed rest versus early mobilization after dural puncture failed to show any evidence of benefit from bed rest and suggested that the risk of PDPH may actually be decreased by early mobilization.
It is notable that the practice of US anesthesiologists regarding bed rest is in contrast to that in UK maternity units, where a survey indicated that 75% of UK consultants encourage mobilization as early as possible following ADP as prophylaxis against PDPH. Likewise, in a randomized prospective trial, increased oral hydration following LP failed to decrease the incidence or duration of PDPH. In summary, at this time there is no evidence to support the common practice of recommending bed rest and aggressive hydration in the prevention of PDPH. Spinal TechniqueNeedle selection is critical for reducing the incidence of PDPH. Given the strong association between needle gauge and PDPH, spinal procedures should be performed with needles having the smallest gauge reasonably possible. However, it should be acknowledged that needles of extremely small gauge can be more difficult to place, have a slow return of CSF, may be associated with multiple unrecognized punctures of the dura, and can result in a higher rate of a failed block. Attention to needle tip design is another important technical means of reducing the risk of PDPH with spinal anesthesia.
If available, noncutting needles should routinely be employed as they appear to be associated with fewer adverse events at a lower overall cost. These factors generally make a 24- to 27-gauge noncutting needle the ideal choice for spinal anesthesia. If cutting-tip needles are used, the bevel should be directed parallel to the long axis of the spine ( Figure 7).Replacing the stylet after CSF collection but prior to needle withdrawal has been shown to be an effective means of lowering the incidence of PDPH after LP.
In a prospective, randomized study of 600 patients with procedures using 21-gauge Sprotte needles, replacing the stylet reduced the incidence of PDPH from 16.3% to 5.0% (p. Physical examination plays a limited role in the diagnosis of PDPH. Vital signs (normal blood pressure and absence of fever) and a basic neurologic exam (gross motor and sensory function plus ocular and facial movements) should be documented. Firm bilateral jugular venous pressure, applied briefly (10–15 seconds), tends to worsen headaches secondary to intracranial hypotension.
Conversely, the “sitting epigastric pressure test” may result in transient relief of PDPH symptoms.101 For this test, the patient is placed in a sitting position until headache symptoms become manifest. Firm, continuous abdominal pressure is applied with one hand, while the other hand is secure against the patient’s back. In cases of PDPH, some improvement is usually noted within 15–30 seconds with prompt return of symptoms on release of abdominal pressure.
It must be appreciated that benign headaches are frequently encountered in the perioperative setting, even in the absence of meningeal puncture, but have generally been noted to be less severe than PDPH (common etiologies include dehydration, hypoglycemia, anxiety, and caffeine withdrawal). With spinal anesthesia, the specific local anesthetic used and the addition of dextrose or epinephrine may influence the occurrence of nonspecific headache but do not affect the rate of true PDPH. The majority of headaches following meningeal puncture will be benign, nonspecific headaches.
In a careful analysis of headache following spinal anesthesia for ambulatory surgery in the general population using strict criteria for PDPH, Santanen and colleagues found an incidence of non-MPH of 18.5%, with an incidence of true PDPH of only 1.5%. Headaches and neck/shoulder pain are also common in the postpartum period.37 In one study, 39% of postpartum patients were noted to be symptomatic, but over 75% of these issues were determined to be primary headaches (migraine, tension type, cervicogenic, and cluster). In this analysis, while 89% of patients received neuraxial anesthesia, only 4.7% of postpartum headaches were PDPH. Benign headaches can often be differentiated from PDPH by their characteristic features. Exacerbation of chronic headache (eg, tension-type, cluster, or migraine) is usually notable for a history of similar headaches.
In the study cited immediately in the preceding paragraph, a previous headache history was a significant risk factor for postpartum headache (adjusted odds ratio = 2.25, if 12 episodes per year). Significant hypertension may cause headaches and should be detected through routine vital sign assessment. Stella et al studied severe and unrelenting postpartum headaches with onset more than 24 hours from the time of delivery and found that 39% were tension-type headaches, 24% were due to preeclampsia/eclampsia, and only 16% were PDPHs (despite neuraxial anesthesia in 88% of patients).Based on this observation, they recommended treatment of tension/migraine headache prior to consideration of PDPH. Pneumocephalus can produce a positional headache that can be difficult to distinguish from PDPH and does not respond to EBP but is readily diagnosed with computerized tomography (CT). Sinusitis may be associated with purulent nasal discharge and tenderness over the affected sinus and is often improved with assuming an upright position.
It should be kept in mind that headache is also a side effect of some commonly utilized pharmacologic agents, such as ondansetron.106 Although certainly unusual, classic PDPH symptoms may even conceivably represent a coincidental case of spontaneous intracranial hypotension (SIH). A number of other benign etiologies are possible. Serious causes of headache will be rare but must be excluded.
It is important to remember that lateralizing neurologic signs (with the exception of cranial nerve palsies), fever/chills, seizures, or changes in mental status are not consistent with a diagnosis of PDPH. Meningitis tends to be associated with fever, leukocytosis, changes in mental status, and meningeal signs (such as nuchal rigidity). Subdural hematoma (SDH) is a recognized complication of dural puncture and is believed under these circumstances to be due to intracranial hypotension resulting in excessive traction on cerebral vessels, leading to their disruption.Practitioners must maintain a high index of suspicion for SDH, which is often preceded by typical PDPH symptoms but progresses to lose its postural component and may evolve to include disturbances in mentation and focal neurologic signs. It has been proposed that early definitive treatment of severe PDPH may serve to prevent SDH. Subarachnoid hemorrhage, most commonly due to rupture of a cerebral aneurysm or arteriovenous malformation, is usually associated with the sudden onset of excruciating headache followed by a decreased level of consciousness or coma.110 Preeclampsia/eclampsia often presents with headache and may only become evident in the postpartum period. Intracranial venous thrombosis (ICVT) is most often seen in the postpartum obstetric population, where headache symptoms are easily confused with PDPH but may progress to seizures, focal neurologic signs, and coma.
Predisposing factors for ICVT include hypercoagulability, dehydration, and inflammatory and infectious diseases. Reports of other intracranial pathology (intracranial tumor, intracerebral hemorrhage, etc.) misdiagnosed as PDPH are extremely uncommon and will be detected with a thorough neurological evaluation.Diagnosis of PDPH can be particularly challenging in patients who have undergone LP as part of a diagnostic workup for headache. In these situations, a change in the quality of headache, most commonly a new postural nature, points toward PDPH. Occasionally, if the benign diagnostic possibilities cannot be narrowed down with certainty, a favorable response to EBP can provide definitive evidence for a diagnosis of PDPH. TREATMENTOnce a diagnosis of PDPH has been made, patients should be provided a straightforward explanation of the presumed etiology, anticipated natural course (factoring in the time from meningeal puncture), and a realistic assessment of treatment options (with consideration of needle gauge). Treatment considerations are presented individually next. Although surveys indicate that formal protocols for management of PDPH are common practice in the United Kingdom, such plans remain the exception in North American practice.
A treatment algorithm, based primarily on the severity of symptoms, can serve as a useful guide for management ( Figure 8). Treatment algorithm for established PDPH (see text for further details). (1) Patient education, reassurance, and supportive measures. (2) Triage by severity of symptoms. (3) Resolution over time without further treatment. (4) Worsening symptoms or failure to improve substantially within 5 days. (5) Choice of EBP or pharmacologic measures based on patient preference.
(6) Definitive treatment (EBP) is recommended (bold arrow). (7) Caffeine or other agents. (8) Failure, worsening of symptoms, or recurrence. (9) Patch materials other than blood remain preliminary.
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(10) Generally performed no sooner than 24 hours after a first EBP. (11) Serious reconsideration of diagnosis. (12) Radiologic guidance is recommended if another epidural blood patch (EBP). (Reproduced with permission from Neal JM, Rathmell JP: Complications in Regional Anesthesia and Pain Medicine, 2nd ed.
Philadelphia: Lippincott Williams & Wilkins; 2013.) TimeBecause PDPH is a complication that tends to resolve spontaneously, the simple passage of time plays an important role in the appropriate management of this disorder. Prior to the introduction of the EBP as definitive therapy, the natural history of PDPH was documented by Vandam and Dripps as they followed 1011 episodes of PDPH after spinal anesthesia using cutting needles of various sizes. While their analysis was flawed by a lack of information regarding duration in 9% of patients, if one considers their observed data, spontaneous resolution of PDPH was seen in 59% of cases within 4 days and 80% within 1 week.More recently, Lybecker et al closely followed 75 episodes of PDPH after spinal anesthesia and, while providing an EBP to 40% of their patients (generally to those having the most severe symptoms), observed in the untreated patients a median duration of symptoms of 5 days with a range of 1–12 days. Van Kooten et al, in a small but prospective, randomized, blinded study of patients with moderate or severe PDPH following LP primarily using 20 gauge needles, noted 18 of 21 patients (86%) in the control treatment group (24-hour bed rest, at least 2 L of fluids by mouth daily, and analgesics as needed) still having headache symptoms at 7 days, with over half of these still rating symptoms as moderate or severe115 ( Figure 9). Cumulative probability of recovery from PDPH.
Recovery from moderate-to-severe PDPH after diagnostic LP in 40 patients. At 7 days, only 3 of 21 conservatively treated patients had fully recovered (no headache symptoms) versus 16 of 19 patients treated with EBP (p 6 on a 1–10 scale). Informed consent for the EBP should include a discussion with the patient regarding the common as well as serious risks involved, true success rate, and anticipated side effects. Finally, patients should be provided with clear instructions for the provision of timely medical attention should they experience a recurrence of symptoms. A number of controversies surround the EBP, reflecting the scarcity of adequately powered, randomized trials. The procedure itself has been well described and consists of the sterile injection of fresh autologous blood near the previous dural puncture ( Table 2). An MRI study of the EBP in 5 young patients (ages 31–44) using 20 mL blood noted a spread of 4.6 ± 0.9 intervertebral spaces (mean ± SD), averaging 3.5 levels above and 1 level below the site of injection.
This and other observations of a preferential cephalad spread of blood in the lumbar epidural space has led to the common recommendation to perform the EBP “at or below” the meningeal puncture level. However, the influence of the level of placement and use of an epidural catheter (often situated considerably cephalad to a meningeal puncture) on efficacy for EBP has never been clinically evaluated. The optimal timing of the EBP is a matter of debate. After diagnosis, most practitioners prefer to delay performing the EBP, possibly to further confirm the diagnosis as well as to allow an opportunity for spontaneous resolution. A 1996 survey of UK neurological departments found that only 8% would consider the EBP before 72 hours had passed following LP. A recent survey of UK maternity units reported that 71% would perform the EBP only “after the failure of conservative measures.”.
Epidural blood patch procedure. Obtain written informed consent.Establish intravenous access.
To the Editor,Postdural puncture headache (PDPH) is a complication following dural puncture. Incidence varies from 0.3% to 20% following spinal anesthesia and about 70% after an accidental dural puncture. Symptoms develop within 48 h to 5 days after the procedure. In 70%, the headache resolves in a week, and in 87% of cases, it resolves within 6 months or it takes 6 months to resolve. PDPH persisting longer than 6 months, however, has been documented. PDPH can be severe and incapacitating, delay recovery and discharge from hospital adding to the cost of treatment. We report a case of severe PDPH refractory to conventional treatment that responded to the use of pregabalin.A 33-year-old female, a known case of pulmonary hypertension diagnosed with carcinoma of the stomach, was scheduled for partial gastrectomy under general anesthesia.
She was on treatment with tablet bosentan, a dual endothelin receptor antagonist in a dose of 62.5 mg twice daily and tablet frusemide 20 mg once daily. An echocardiogram revealed a pulmonary arterial systolic pressure of 54.9 mmHg, dilated cardiac chambers, mild mitral regurgitation and an ejection fraction of 60%.A 20G, thoracic epidural catheter was inserted for perioperative analgesia.
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An accidental dural puncture resulted in the T8-T9 interspace with an 18G Tuohy needle (Portex) at first attempt. The catheter was successfully inserted thereafter in the T7-T8 interspace. Intraoperatively, an epidural infusion of 0.125% bupivacaine and 2 mcg/ml fentanyl at 5 mL/h was started and continued postoperatively at 6 mL/h. On 1 st postoperative day, the patient complained of a headache in the fronto-occipital region, which she rated as six on the numerical rating scale (NRS), worse on sitting, not associated with nausea, vomiting, tinnitus, hearing loss, neck stiffness or fever.
She was started on intravenous paracetamol, 1 g and intravenous diclofenac potassium 50 mg thrice daily with judicious intravenous fluids. Once allowed oral liquids, she was advised 3-4 cups of coffee/day, one tablet paracetamol 650 mg with 50 mg caffeine, 4 times a day and plenty of oral fluids. The intensity reduced, but the headache persisted. On 6 th postoperative day, she complained of severe headache (8/10 on the NRS) with tinnitus that appeared on walking. The patient was distressed but not willing for a blood patch.On 8 th postoperative day, the patient's discharge was postponed due to the headache.
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As a last resort, she was started on tablet pregabalin, 75 mg once only at night.