Although prophylaxis is most simply thought of as preventing any symptoms of PDPH, in the clinical context this issue is deceptively complex. Unfortunately, despite the clear relevance of this issue, the overall quality of evidence for preventive measures is generally weak. As 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.
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. 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.
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.
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. Needle 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 to 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. In a prospective, randomized study of patients with procedures using gauge Sprotte needles, replacing the stylet reduced the incidence of PDPH from This safe-and-simple maneuver is theorized to decrease the possibility of a wicking strand of arachnoid mater from extending across the dura.
However, in a more recent study of patients having spinal anesthesia using gauge Quincke needles, replacing the stylet did not affect the incidence of PDPH. The disparity in these results may be related to the needle gauges used as well as fundamental differences between the techniques of lumbar puncture drainage of CSF and spinal anesthesia injection of anesthetic agent.
Continuous spinal anesthesia CSA has been reported by some to be associated with surprisingly low incidences of PDPH compared with single-dose spinal techniques using similar-gauge needles. This observation has been attributed to reaction to the catheter, which may promote better sealing of a breach in the meninges. No patients in either group required EBP. Although epidural options are limited, especially with catheter techniques, the risk of PDPH following ADP can be reduced by using the smallest feasible epidural needles.
The issue of air versus liquid for identification of the epidural space with the loss-of-resistance technique has long been a source of controversy. Each method has acknowledged advantages and disadvantages, but neither has been shown convincingly to result in a lower risk of ADP. Bevel orientation for epidural needle insertion remains a matter of debate.
It appears that a number of concerns regarding parallel needle insertion lateral needle deviation, difficulties with catheter insertion, and dural trauma with needle rotation are of greater concern to practitioners. Most respondents This observation may be due to several factors, including the ability to successfully use extremely small eg, gauge noncutting spinal needles and tamponade provided by epidural infusions.
The risk-to-benefit ratio of prophylaxis should be most favorable in situations having the greatest likelihood of developing severe PDPH. Several prophylactic measures, discussed in the material that follows, are worthy of consideration and have been utilized alone or in combination.
However, because not all patients who experience ADP will develop PDPH, and only a portion of those who do will require definitive treatment with an EBP, a cautious approach in this regard is still generally warranted. It should be acknowledged that the efficacy of all the measures discussed next is debatable.
Therefore, it is critical that in the event of recognized ADP, these patients at the very least be clearly informed of the high risk of PDPH development and be followed daily until discharge or called at home if discharged within 48 hours. Stylet Replacement Although there have not been any studies to support the use of the stylet replacement technique in the setting of ADP, replacing the stylet is a simple and effective means of lowering the incidence of PDPH after LP.
Given the innocuous nature of this maneuver, if no other prophylactic measures are taken, there appears to be little reason not to replace the stylet prior to epidural needle removal in the event of ADP. Subarachnoid Saline Limited evidence indicates that the subarachnoid injection of sterile preservative-free saline following ADP may be associated with a significant reduction in the incidence of PDPH and need for EBP.
However, given the relatively rapid rate of CSF regeneration, it may be that the benefit of fluid injection following ADP is actually in preventing a wicking strand of arachnoid as proposed for stylet replacement after LP. Further investigation into this issue is needed. Intravenous Cosyntropin As mentioned, there is no convincing evidence that systemic pharmacologic measures are beneficial in the prevention of PDPH. However, based on a number of theoretical mechanisms, corticotropin adrenocorticotrophic hormone, ACTH and its analogs have long been used in the treatment of PDPH.
Hakim recently reported randomizing 90 parturients experiencing ADP to receive either 1 mg cosyntropin or saline intravenously 30 minutes after delivery.
No serious reactions were associated with cosyntropin use. These limited data are encouraging but will need to be supported through further study. While these measures are not uncommonly recommended in UK maternity units such management is rare in US practice. Immediately placing an intrathecal catheter ITC after ADP has the advantages of being able to rapidly provide spinal analgesia as well as eliminate the possibility of another ADP under challenging clinical circumstances.
However, the potential benefits of ITC use must be weighed against the readily appreciated risks involved accidental use, misuse, and infection. The mechanism of benefit from ITCs is unclear but may be due to reaction to the catheter, with inflammation or edema preventing further CSF loss after removal.
In their obstetric population, catheter placement resulted in a PDPH rate of only 6. However, this impressive reduction in the incidence of PDPH has generally not been duplicated.
It should be noted that benefits have often not been reported in studies where catheters have been left in situ for less than 24 hours. There are also preliminary data to suggest that the incidence of PDPH may be further reduced by the injection of preservative-free saline through an ITC immediately prior to removal.
With some accepted and other possible benefits, rates of ITC use following ADP have clearly increased during the past decade. Although ITC use has become more common, reattempting an epidural at an adjacent interspace remains the preferred action following ADP.
Provided an epidural catheter can be successfully placed, several epidural approaches have been used in hope of reducing the incidence and severity of PDPH. Epidural Saline Efforts regarding epidural saline have included both bolus usually around 50 mL as a single or repeated injection and continuous infusion techniques commonly — mL over 24 hours.
As these measures are resource intensive and may only serve to delay the inevitable onset of symptoms, they have generally not been continued beyond 36 hours. Other studies of epidural saline have noted this modest decrease in the incidence of PDPH.
Epidural Opiates Epidural opiates especially morphine , while long utilized for the treatment of PDPH, have been thought unlikely to influence the natural history of the disorder. Research into the efficacy of the EBP for prophylaxis has yielded mixed results, and closer scrutiny indicates that optimism should be guarded. The primary benefit of the PEBP was a shorter total duration of symptoms from a median of approximately 5 days to 2 days and, consequently, a reduction in the overall pain burden.
While there are studies that have shown greater benefit from PEBP, systematic reviews of the evidence have repeatedly noted the inferior methodology of these other studies when compared with that of Scavone et al. With such inconclusive support, the PEBP is not currently recommended as a routine measure based on available evidence. Due to concerns of exposing patients to a potentially unnecessary and marginally beneficial procedure, prophylactic application of the EBP has declined substantially in recent years.
If used for prophylaxis, the EBP should be performed only after any spinal or epidural local anesthetic has worn off, as premature administration has been associated with excessive cephalad displacement of local anesthetic.
Residual epidural local anesthetic may also inhibit coagulation of blood, further decreasing the efficacy of the EBP. Postdural puncture headache remains a diagnosis of exclusion. Although headache following meningeal puncture will naturally be suspected to be PDPH, it remains critical to rule out other etiologies Table 1.
Fortunately, a careful history with a brief consideration of other possible diagnoses is usually all that is necessary to differentiate PDPH from other causes of headache. While numerous clinical variations have been reported, most cases of PDPH will have a a history of known or possible meningeal puncture, b delayed onset of symptoms but within 48 hours , and c bilateral postural headache possibly accompanied by associated symptoms if moderate or severe.
Importantly, most non-MPHs will not have a strong positional nature. Laboratory studies are usually not necessary for the diagnosis of PDPH and, if obtained, are generally unremarkable most commonly, MRI may show meningeal enhancement and LP may reveal low opening pressures and increased CSF protein. 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. 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 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. Significant hypertension may cause headaches and should be detected through routine vital sign assessment.
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.
A number of other benign etiologies are possible. Serious causes of headache will be rare but must be excluded. 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. 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.
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. 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.
Once 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. Because 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.
These data serve to illustrate the unpredictable and occasionally prolonged duration of untreated PDPH. Given this reality, it is not surprising that there are a number of case reports of successful treatment of PDPH months and even years after known or occult meningeal puncture.
Largely due to the self-limited nature of PDPH, the optimal time course of treatment has not been well defined. Clinically, the practical issue is how long definitive therapy ie, the EBP can appropriately be delayed.
Many practitioners currently advocate a trial, most commonly 24—48 hours, of conservative management. However, the rationale behind this approach is questionable given the often severely disabling nature of symptoms, particularly in the postpartum period when newborn care may be significantly impaired. Reassurance and measures directed toward minimizing symptoms, while not expected to alter the natural course of the disorder, are advised for all patients. By definition, the majority of patients with moderate-to-severe PDPH will naturally seek a recumbent position for symptomatic relief.
Despite a lack of supportive evidence, aggressive hydration continues to be the most frequently recommended practice utilized in treatment of PDPH. Although aggressive hydration does not appear to influence the duration of symptoms,74 patients should and often must be encouraged to avoid dehydration. This question becomes more unclear if the new procedure includes a steroid medication.
As an example, an older patient presents with a history of lumbar disc disease and during lumbar epidural steroid injection, an inadvertent wet tap occurs leading to PDPH. Following management with fluids, caffeine, medications, and a successful epidural blood patch, it remains unclear as to when would be the best time frame to consider a second lumbar epidural steroid injection.
We identified the 3 main risk factors of subsequent interventional neuraxial procedures as 1 disruption of the epidural blood patch and ongoing reparative processes, 2 epidural procedure failure, and 3 infection. Parturients' records were reviewed to establish the characteristics and associated symptoms of headache and the effectiveness of the epidural blood patch. Results: A total of parturients received epidural blood patches. Conclusions: Epidural blood patch performed later than 48 h following lumbar puncture or accidental dural puncture is effective in parturients with postdural puncture symptoms.
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