Ebook A practical approach to obstetric anesthesia (2/E): Part 2

(BQ) Part 2 book “A practical approach to obstetric anesthesia” has contents: Ultrasound and echocardiographic techniques in obstetric anesthesia, impact of neuraxial analgesia on obstetric outcomes, newborn resuscitation, obstetric emergencies, postcesarean analgesia, postpartum tubal ligation, endocrine disorders, management of the opioid dependent parturient,… and other contents.

Postpartum Issues

2

Opioids are the mainstay of post-CD analgesia Intravenous patient-controlled analgesia (PCA) opioid administration provides superior painrelief compared to intermittent caregiver administration and may have

3 Neuraxial opioids are the gold standard in providing post-CD analgesia

by decreasing overall opioid consumption, improving ambulation,

allowing earlier return of bowel function, and improving reductions inbreast milk levels of opioids compared to systemically administered

opioids

4 Neuraxial opioids are associated with nausea, vomiting, urinary retention,respiratory depression, and pruritus

7 Predicting the effects of maternally administered medications that appear

in breast milk is complex Consulting the published guidelines written byprofessional organizations is recommended

I. Introduction

Pain relief after cesarean delivery (CD) has many of the same clinicalconsiderations as analgesia following other forms of abdominal

surgery Additional concerns in the post-CD population include thegoal of minimizing maternal sedation to facilitate interactions with thenewborn, family, and friends; transfer of analgesic medications inbreast milk; and reducing time to discharge to home CD is a verycommon surgical procedure, and anesthesiologists should be familiar

with current post-CD analgesic techniques More than 1.28 million

CD were performed in the United States in 2013, representing 32.7% of all births.1 As seen in the subsequent text, the anestheticmethod used for CD often influences the choices for postcesareananalgesia Both scheduled and unplanned CD have similar acute

Acute postoperative or nociceptive pain following CD is a combination of visceral pain from the uterus and somatic pain from the abdominal wall Recent research has focused on the

subsequent development of chronic neuropathic pain at the abdominalincision site Retrospective and prospective studies of chronic painafter CD report an incidence range of 1% to 18%.3 At this time,

modifications of post-CD analgesia to decrease the incidence of

chronic incisional pain are investigational only This chapter focuses

on current analgesic strategies for acute nociceptive post-CD pain.However, some data suggest that effective treatment of acute

postoperative pain may minimize the development of chronic pain inthese patients.4

Effective post-CD analgesia is an attainable goal recommended

by several national professional organizations.5,6 One prospectivewritten survey of pregnant patients before delivery demonstrates thatpain during and after CD are the two most concerning anesthesiaoutcomes.7 A prospective study of healthy parturients shows thatpreoperative questions about anxiety, expected postoperative pain,and expected needs of postoperative analgesic medications are

moderately predictive of post-CD analgesic requirements.8 However,the practical application of preoperative questionnaires for routineclinical practice is not clear

B Components of multimodal therapy Examples of multimodal

therapy for post-CD analgesia include different combinations ofthe following:

1 Systemic opioids

a Specific medications studied include morphine,

meperidine, hydromorphone, fentanyl, sufentanil,oxymorphone, butorphanol, and diamorphine Choice ofopioid is influenced by its overall direct effects, time ofonset, duration of action, and the frequency and nature ofside effects

b IV meperidine is seldom used for post-CD analgesia due to concerns about infant sedation by the active metabolite, normeperidine.10 However, patient-controlled epidural analgesia (PCEA) with meperidineresults in lower maternal systemic doses that should be

c Diamorphine (heroin) is a Drug Enforcement

Administration (DEA) Schedule I medication and notavailable for clinical use in the United States, although ithas enjoyed widespread epidural and IT use in the UnitedKingdom and other parts of Europe

controlled analgesia (PCA), provides superior post-CD analgesia compared to the IM route.12

d IV opioid administration, particularly by patient-e Direct comparisons of demand-only IV PCA with IV PCA

and continuous basal infusion are limited in women after

CD.13 In the absence of a definite overall advantage ofbasal infusion IV PCA, along with safety concerns

regarding respiratory depression associated with the basalinfusion rates in other postsurgical populations,14 the

receiving unsafe doses of IV opioid First, the PCA

pump is programmed to limit the amount of opioid perpatient request and per hour Second, if the patient is verysedated, she will be unable to push the PCA demand

button and the current opioid effect will diminish

Unfortunately, even with these safeguards, adverse

outcomes have occurred with IV PCA in post-CD patients Examples include visitors activating the PCA

demand button for the patient (i.e., PCA by proxy) andmedication and programming errors.15,16

IV PCA opioid administration offers superior pain relief compared to intermittent administration by

b The rationale for neuraxial (i.e., epidural or spinal) administration of opioids is to improve the analgesic efficacy while minimizing the side effects of the opioids when administered by other routes These side effects

include sedation, respiratory depression, nausea andvomiting, itching, and urinary retention However, allthese side effects can occur with either systemic orneuraxial opioids

c A single dose of epidural morphine:

(1) Provides better post-CD analgesia than a saline placebo17 or IM opioids12,18

(2) Has similar analgesic efficacy and patient satisfaction compared to IV PCA morphine12,18(3) Is associated with more pruritus than IV PCA or

IM morphine (4) May be less effective than if given by continuous infusion19

differences between DepoDur and conventional morphine were restricted to the 24 to 48 hour postoperative time frame, but the magnitude of those differences was clinically modest.

(3) Although it is approved for clinical use, it is currently

not being produced by the pharmaceutical company,Pacira, who currently own the license They are usingthe carrier, DepoFoam to manufacture the long actinglocal anesthetic preparation, Exparel

g Table 18.2 lists the recommended single doses of

conventional epidural opioids, based on prospective

randomized studies

(1) Clonidine (75 to 150 µg) improves post-CD

analgesia when added to single epidural doses offentanyl or morphine.29,30 However, there is an FDA black box warning for clonidine “Duraclon®

(epidural clonidine) is not recommended forobstetric, postpartum, or perioperative painmanagement ” Use of clonidine alone does notoffer significant analgesic improvement overneuraxial opioid use, and the associated side effects

of frequent sedation and hypotension mitigate againstits routine use

(2) Epinephrine has demonstrated inconsistent effects in

improving analgesia and reducing side effects whenadded to single doses of epidural opioids

(3) The use of N-methyl-D-aspartate (NMDA)

antagonists (e.g., ketamine, magnesium), although

safe and effective in producing analgesia in a verylimited number of studies, should be consideredexperimental at present

4 Intrathecal Opioids

a Specific medications studied include morphine,

meperidine, fentanyl, sufentanil, nalbuphine, butorphanol,and buprenorphine

b In contrast to systemic and epidural routes of

administration, IT administration of opioids does not

lead to clinically significant maternal serum

concentrations of these agents.31,32

d Direct comparisons of the IT and epidural routes of administration for single-dose morphine show similar efficacy for post-CD analgesia.31,32 However, the

maternal intraoperative sedation.34,35 Refer to sectionIII.A.3.h.(1) for the FDA “black box” warning onneuraxial clonidine

(2) Neostigmine (12.5 μg) improves post-CD analgesia

and may reduce side effects when added to a

subtherapeutic dose of IT morphine.36 Its short

duration of action and side effect profile do notconvey significant benefit over use of neuraxialopioids

single-shot neuraxial morphine.

5 Opioid side effects

a Respiratory depression, with the risk of apnea and hypoxic injury or death, is the most serious side effect

of opioids This complication is encountered in postoperative patients after opioid administration by any route The American Society of Anesthesiologists developed a practice guideline focused on potential

respiratory depression after neuraxial opioidadministration.37 Some recommendations included in thisdocument are:

(1) The anesthesiologist should conduct a focused

history and physical examination to identify patientcharacteristics associated with a risk of respiratorydepression (obesity, obstructive sleep apnea,

coexisting respiratory disease)

(2) Although neuraxial opioids may be safely used in

place of parenteral opioids without increasing the risk

of respiratory depression, the concomitantadministration of parenteral opioids and othersedatives requires increased monitoring due to

(3) All patients receiving neuraxial opioids should be

monitored for the adequacy of ventilation (respiratoryrate, depth of breathing), oxygenation (pulse

be performed for a period of 24 hours, with

monitoring at hourly intervals for the first 12 hoursand every 2 hours for the next 12 hours

(5) Supplemental oxygen should be available to all

patients and administered to those with signs of

respiratory depression or hypoxemia An IV lineshould be maintained for administration of reversalagents if needed

(6) Women after CD may be at lower risk for respiratory

depression after neuraxial opioid use compared toother surgical patients A recent retrospective study ofwomen after CD treated with common doses of

epidural or spinal morphine found no instances ofrespiratory depression in more than 5,000 patients.38

b Pruritus is a common side effect of neuraxial opioid treatment In many instances, it seems to worsen with

increasing doses of a given opioid and may be more

intense with IT as opposed to epidural administration Anumber of therapies have been proposed.39

(1) Opioid antagonists The most consistent treatment

is with opioid antagonist medications, either a pure

antagonist (e.g., naloxone40) or a mixed agonist–

antagonist (e.g., nalbuphine41)

(2) Diphenhydramine Diphenhydramine 25 mg IV can

be helpful in the treatment of pruritus Although itsmechanism of action in this setting is unknown, it canproduce profound sedation Because opioid-inducedpruritus does not appear to be mediated by histaminerelease, the antihistamine-effects of diphenhydramine

do not appear to play a significant role in reducingpruritus

(3) 5-HT3 receptor antagonists Because morphine is

known to activate 5-HT3 receptors by a mechanismindependent of opioid receptors, morphine maydirectly stimulate 5-HT3 receptors and cause ITmorphine-induced pruritus Consequently, occupation

of 5-HT3 receptors by a 5-HT3 receptor antagonistpotentially prevents the pruritus Both ondansetronand dolasetron have been administered

induced pruritus with variable results

prophylactically in the treatment of IT morphine-c Nausea and vomiting has a multifactorial etiology after

CD.39 Clearly, opioids can contribute significantly to thisproblem As with pruritus, one strategy has been to

minimize opioid doses whenever possible throughmultimodal therapy There is little consensus aboutspecific therapies to prevent or treat postcesarean nauseaand vomiting Table 18.4 provides suggested prophylacticand therapeutic interventions for nausea and vomiting

Opioid agonist/antagonist drugs are

administered opioids Nausea and vomiting are effectively treated with a variety of medications because many factors affect its

b Adding a local anesthetic to an epidural opioid infusion

may have a dose-sparing effect,42 but it can result inlower extremity motor block and delayed ambulation inwomen after CD.43

2 Iliohypogastric and ilioinguinal peripheral nerve blocks

a These two peripheral nerves originate from the L1 spinal

nerve root and innervate the abdominal wall region thatcorresponds to a lower transverse cesarean incision Theblocks need to be performed bilaterally

b The existing literature with single-shot nerve blocks

presents conflicting results about the effectiveness ofperioperative placement of these blocks in decreasingsubsequent supplemental opioid use after low transverse

CD.44–46

c A case series of ultrasound-guided continuous ilioinguinal

and iliohypogastric nerve blocks in post-CD patientsdescribes apparent opioid-sparing in the postoperativeperiod.47

3 Transversus abdominis plane blocks

a A transversus abdominis plane (TAP) block is a lower

abdominal wall block accomplished by placing local

mL of local anesthetic per side Although initially

described using surface anatomy landmarks, it is nowplaced with real-time ultrasound guidance

b When used after spinal anesthesia for CD, the TAP block

adds value only when IT morphine is omitted from amultimodal analgesic regimen.48,49 A prospective directcomparison study in post-CD patients demonstrates that

IT morphine is a more effective analgesic technique

compared to a TAP block, but with a higher side effectprofile.50 A case series in this patient population describes

indicated Adding 75 µg of clonidine to each side of a

post-CD local anesthetic TAP block did not improve itsperformance in a multimodal analgesic regimen that

b Postoperative wound infusion, using a catheter

inserted at the time of surgery, is an effective post-CD

analgesic technique.57,58 Direct comparisons showpostoperative wound infusions with local anesthetics aremore effective than epidural morphine and similar tosystemic diclofenac.58,59 Catheter infusions are mosteffective when located deep to the fascia at the time ofwound closure60 and should be placed using ultrasoundguidance to improve success

c Postoperative wound infusions with local anesthesia affect

specific inflammatory mediators measured in woundexudates, suggesting an interaction with the woundhealing process.61

d It remains to be seen if infiltration of the wound with

Exparel®, the long acting local anesthetic product,improves post-CD analgesia, especially on day 2postoperatively

TAP blocks do not offer improved analgesia when added to single-shot neuraxially administered morphine.

analgesic effects similar to codeine-acetaminophencombinations.62

2 NSAIDs are typically administered by the PO, IV, or rectal

routes Recent studies have described direct postoperativewound infiltration with NSAIDs, using a continuous infusionthrough a wound catheter inserted at CD In one study,

infiltration and more effective than systemic diclofenac.63 Asecond study described the effects of adding ketorolac (0.6

mg per hour) to bupivacaine for continuous wound

infiltration.64 In this regimen, ketorolac improved analgesiaand altered inflammatory mediators in wound exudates Theauthors concluded that NSAID administration directly into asurgical wound is a strategy to accomplish the analgesia ofNSAIDs while minimizing their systemic side effects

acetaminophen had slightly better pain scores than patientswith IV PCA morphine.65

CD without IT morphine, patients receiving oral oxycodone-2 The current clinical interest in acetaminophen as a component

of post-CD multimodal analgesia is driven by two issues:

a Unpredictable factors during CD (such as impaired

hemostasis) may preclude the use of NSAIDs in thepostoperative period

b Recent approval in the United States of an IV formulation

of acetaminophen

3 Following spinal anesthesia for CD without IT morphine,

patients had similar postoperative analgesia with either 1 g IVacetaminophen every 6 hours or 400 mg oral ibuprofen every

4 hours.66

4 Current controversies with acetaminophen include the clinical

efficacy and cost-effectiveness of IV acetaminophencompared to other routes of administration Also, the large IVdoses of acetaminophen raise concerns about unintended toxicdoses when combined with the oral formulations, particularlywhen patients are transferred between clinical services orunits

NSAIDs can be administered orally, IV, and

as adjuncts to local anesthetic neuraxial block for analgesic effects Whether acetaminophen has significant analgesic properties is

2 Gabapentin

Perioperative oral dosing with gabapentin does not produceclinically meaningful post-CD analgesia In addition, it isassociated with increased sedation.70,71

3 Magnesium when administered intravenously demonstrates

minimal reduction in pain scores and modest reduction inopioid use in non-pregnant women after surgery but has not

been evaluated in women after CD.72

The routine use of NMDA receptor antagonist drugs (e.g., magnesium, ketamine) and gabapentinoids for postcesarean analgesia is not currently recommended.

F Medications in breast milk

1 The pharmacokinetics of medications and breast milk are complex, and data are incomplete for many medications.

Breast milk is a combined solution and suspension, and thecomposition changes over the first week postdelivery as thecolostrum transitions to mature milk These factors make it

difficult for health care providers to predict whether individual medications will be present in breast milk in sufficient concentrations to cause a clinically significant effect in the infant.

2 Recent case series and studies have expressed concern over

the variations between individuals in activity of the hepaticcytochrome P450 enzyme 2D6 (CYP2D6) This enzymemetabolizes codeine to its active form (morphine) andoxycodone to oxymorphone Individuals with excessCYP2D6 activity (i.e., ultra-rapid metabolizers) may generateexcess maternal opioid activity, increasing the transfer to theinfant through breast milk This situation can cause sedation

in the mother and baby, but rare fatalities have beenreported.73–75

3 This author’s recommendation is to utilize an authoritative source for decisions about medications and breastfeeding There are two guidelines from professional organizations76,77 and three textbooks78–80 listed in the

reference section of this chapter Ready access to these publications will facilitate clinical decision making and patient communication; this is particularly important

because of common maternal concerns regarding the effects of maternal analgesia on the nursing newborn The

recommendations are not identical, but in general, the

commonly used opioids and NSAIDs for post-CD analgesia are compatible with breastfeeding The

exceptions among the opioids are meperidine, codeine, andoxycodone

The effects of maternally administered drugs is complex and unpredictable The use of published

C. IM route of administration should be considered only as a lastresort

D. NSAIDs have a widespread role in post-CD analgesia, frequently

in addition to opioids

E. Acetaminophen’s use as a postoperative medication continues toevolve, particularly in reference to IV versus other routes ofadministration The total dose in different formulations needs to

be appreciated to minimize the risk of toxicity

F. Patient-controlled catheter infusions are promising techniques andcan be used for postoperative wound infiltration with a localanesthetic and/or NSAID

G. Analgesic medications are mostly compatible with breastfeeding

As discussed earlier, some concerns have been expressedconcerning the administration of meperidine, codeine, oroxycodone to patients who are breastfeeding, based on differentmechanisms of drug metabolism

H. In general, postoperative pain management is an opportunity foranesthesiologists to collaborate with obstetricians and obstetricnurses We have expertise to share that will improve the

postoperative experience for many patients after CD Newinitiatives for post-CD analgesia are unlikely to succeed withoutthe prior knowledge and support of our clinical obstetric andnursing colleagues Also, in the current regulatory climate,hospitals will appreciate assistance in improving patientsatisfaction scores

cesarean delivery Int J Obstet Anesth 2011;20:128–134.

12 Eisenach JC, Grice SC, Dewan DM Patient-controlled analgesia following cesarean section: a

comparison with epidural and intramuscular narcotics Anesthesiology 1988;68:444–448.

13 Sinatra R, Chung KS, Silverman DG, et al An evaluation of morphine and oxymorphone administered via patient-controlled analgesia (PCA) or PCA plus basal infusion in postcesarean-delivery patients.

Anesthesiology 1989;71:502–507.

14 Parker RK, Holtmann B, White PF Effects of a nighttime opioid infusion with PCA therapy on patient

50 Kanazi GE, Aouad MT, Abdallah FW, et al The analgesic efficacy of subarachnoid morphine in comparison with ultrasound-guided transversus abdominis plane block after cesarean delivery: a

62 Nauta M, Landsmeer MLA, Koren G Codeine-acetaminophen versus nonsteroidal anti-inflammatory

drugs in the treatment of post-abdominal surgery pain: a systemic review of randomized trials Am J Surg 2009;198:256–261.

63 Lavand’homme PM, Roelants F, Waterloos H, et al Postoperative analgesic effects of continuous

wound infiltration with diclofenac after elective cesarean delivery Anesthesiology 2007;106:1220–

1225.

64 Carvalho B, Lemmens HJ, Ting V, et al Postoperative subcutaneous instillation of low-dose ketorolac but not hydromorphone reduces wound exudate concentrations of interleukin-6 and interleukin-10 and

Anesthesiology 2015;123:320–326 doi:10.1097/ALN.0000000000000722.

71 Short J, Downey K, Bernstein P, et al A single preoperative dose of gabapentin does not improve postcesarean delivery pain management: a randomized, double-blind, placebo-controlled dose-finding

trial Anesth Analg 2012;115:1336–1342.

L Lactation headache

VI Prevention and treatment of postdural puncture headache after accidental dural puncture

1 Far from being a minor complication, postdural puncture headache

(PDPH) can significantly increase the cost of hospitalization, can have anextremely negative impact on patient satisfaction with a consequent

increase in the risk of litigation, and can lead to significant increases inboth short-and long-term maternal morbidity

2 When evaluating patients with presumed PDPH, it is critically important

to rule out other potentially life-threatening causes of headache

3 Numerous pharmacologic treatments for PDPH have been proposed, butthere is little evidence to support the routine use of a specific drug

4 Although evidence supporting the practice is inconclusive, placement of

an intrathecal catheter after accidental dural puncture may decrease therisk of developing PDPH

5 Although not without its own complications, epidural blood patch (EBP)represents the gold standard for treatment of established PDPH The

routine use of prophylactic EBP and the optimal timing of EBP remaincontroversial

I. Scope of the problem

Despite advances in neuraxial anesthetic techniques, postdural

puncture headache (PDPH) remains a persistent problem Even in

experienced hands, the risk of accidental dural puncture with an epidural needle is approximately 1 in 200, but in many teaching hospitals, the rate is between 1% and 4% When it occurs, PDPH is

often mild in intensity and brief in duration (i.e., 3 to 7 days)

However, PDPH is occasionally severe enough to leave patients

bedridden and can delay hospital discharge Symptoms of PDPH havebeen reported to last months or even years in rare cases.1 UntreatedPDPH can lead to the development of persistent cranial nerve palsiesand intracranial hemorrhage.2,3 Finally, despite a widespread beliefamong physicians that PDPH is merely a nuisance, it is a frequent andsometimes costly source of litigation.4 It is undoubtedly, in the words

of Sachs and Smiley,5 “the worst common complication in obstetricanesthesia.”

of PDPH is described as well as the other types of headache that arecommon in the parturient The rationale for the commonly used

methods for preventing and treating PDPH is discussed on the basis ofour current understanding of the mechanisms of PDPH The evidencesupporting these techniques will be described when such evidenceexists There are few rigorous, well-controlled studies of the treatment

of PDPH, so many of the treatment recommendations will be based

on case reports, observational studies, and the author’s experience.More than 100 years after August Bier6 first described PDPH, itsoptimal management is a question that remains unanswered

II. Pathophysiology

It is well accepted that the proximal cause of PDPH is persistent loss

of cerebrospinal fluid (CSF) through a dural, or more accurately, anarachnoid puncture This leakage leads to headache through one oftwo presumed mechanisms

A Meningeal traction

Continued leak of CSF from a lumbar–dural puncture leads toloss of fluid from the intracranial compartment The loss of acushioning effect from CSF allows the brain to sag within theskull, placing traction on the pain-sensitive meninges, an effectthat becomes most apparent in the upright position This suggeststhat the treatment of PDPH should be based on minimizing CSFleakage, increasing CSF production, or translocating CSF fromthe spinal to the intracranial compartment

B Cerebral vasodilation

The second theory is based on the Monro-Kellie hypothesis,which states that the sum of brain tissue, CSF, and intracranialblood is constant Thus, a decrease in intracranial CSF will lead

to an increase in intracranial blood, mediated through

compensatory cerebral vasodilation This suggests that PDPH issimilar to migraine headache, a theory supported by the similarlyincreased incidence of migraine and PDPH in women, and also

by magnetic resonance imaging (MRI) studies that demonstrateenhanced cerebral blood flow in PDPH.7 This theory suggests notonly that PDPH will be relieved by restoration of intracranial CSFvolume but also that cerebral vasoconstrictors might providesymptomatic relief

III. Risk factors for postdural puncture headache

A Unmodifiable risk factors

1 Age Headache is uncommon in elderly patients The highest

risk group appears to be patients younger than 40 years ofage, an age range typical for most parturients

2 Gender A recent meta-analysis concluded that nonpregnant

females are more likely to develop PDPH than males, despitethe fact that the women studied were considerably older, adifference which would be expected to decrease the incidence

4 Previous postdural puncture headache A history of prior

PDPH is a risk factor for headache after spinal anesthesia.11

Pregnancy and a prior history of PDPH convey greater risk for the development of PDPH.

B Modifiable risk factors

1 Needle size Numerous studies show that there is a consistent

decrease in the incidence of PDPH as the needle diameter getssmaller With needles <27 gauge, the increasing technicaldifficulty of needle placement limits the usefulness of furtherdecreases in diameter

2 Needle shape For any needle diameter, the use of conical or

“pencil-point” needles (e.g., Whitacre, Sprotte, Gertie Marx)consistently decreases the incidence of PDPH compared tocutting-bevel (e.g., Quincke) needles.12

3 Orientation of needle bevel When a cutting-bevel needle is

used, insertion of the needle with the bevel parallel to thelongitudinal axis of the body will significantly decrease therisk of headache.13

4 Paramedian approach Although used infrequently in

obstetrics, subarachnoid block performed through theparamedian approach appears to significantly decrease theincidence of PDPH.14

5 Morbid obesity It has long been thought that the incidence

of PDPH is decreased in morbidly obese parturients.15 Arecent study, adds further evidence that obesity providesprotection against the development of PDPH.16

The use of small pencil-point spinal needles, with the bevel of a cutting needle oriented parallel to the spinal axis, and a paramedian approach reduces the risk of PDPH.

recumbency Absence of a postural component must cast

doubt on the diagnosis of PDPH The onset of headache

may be delayed by as long as 15 minutes after assuming theupright position; however, the absence of a headache

immediately after positional change does not rule out PDPH

2 Location Typically, headache is distributed in the frontal and

occipital regions, with radiation to the neck and shoulders.Pain in the interscapular region of the upper back may beobserved

3 Auditory disturbances Decreased CSF pressure is

transmitted to the cochlea, often producing auditorysymptoms such as decreased acuity, tinnitus, and what is oftendescribed as a “hollow” sound

4 Visual disturbances Diplopia is common, typically due to

paresis of lateral gaze due to compression of cranial nerve VIalong its long course in the middle fossa by the sagging brain

The onset of headache in a patient with PDPH may be delayed by as much as 15 minutes after assuming the upright position.

V. Differential diagnosis of postpartum headache

It is important to rule out other possible causes for headache in thepostpartum period (see Table 19.1), both to prevent the unnecessaryuse of invasive treatments, such as epidural blood patch (EBP), totreat benign and self-limiting conditions and, more importantly, toensure that potentially life-threatening intracranial pathology is notoverlooked.17,18

A Migraine Headaches caused by migraine are divided into two subtypes: migraine with aura and migraine without aura In

the former, reversible neurologic symptoms, typically visual butoften involving facial numbness or motor deficits in the arms orlegs, develop over 5 to 20 minutes and resolve within 1 hour.Both subtypes are characterized by unilateral, pulsating pain,worsened by activity, and often associated with nausea and

photophobia Migraine usually begins in adolescence, is morecommon in women, often improves during pregnancy, but alsofrequently recurs in the early postpartum period New onset ofmigraine during pregnancy or postpartum is unusual and warrantsinvestigation

B Tension headache Tension headache is the most common type

of headache and is more common in women In contrast to

migraine, tension headaches seldom begin in adolescence and aremore likely to occur in middle age These headaches are of mild-to-moderate intensity and are usually bilateral, nonpulsating, andunaffected by activity Nausea and photophobia are absent

Pregnancy appears to increase the incidence of tension headache

C Intracranial hemorrhage Headache due to intracranial

hemorrhage is characterized by sudden onset, intense severity,and the presence of focal neurologic signs or alterations in thelevel of consciousness

1 Subarachnoid hemorrhage The incidence of SAH does not

proteinuria are common, and SAH may be confused withpreeclampsia.19

hematoma; both may exist simultaneously This should beconsidered when the character of a PDPH changes after

b When a cortical vein is thrombosed, focal motor and

sensory deficits and seizures are more likely to beobserved

3 There are several reported cases of intracranial thrombosis

in fact be a risk factor for the development of cerebral venousthrombosis.21 The presence of signs and symptoms suggestingintracranial hypertension should lead to a more thoroughevaluation before EBP is performed (i.e., MRI or magneticresonance angiography)

4 Venous thrombotic occlusion leads to increased capillary

pressure, often causing hemorrhagic infarcts With

recanalization of the vessel, capillary pressure decreases andfurther hemorrhage is prevented Heparin prevents furtherthrombus formation; therefore, its use is indicated, even inpatients with preexisting hemorrhage

E Neoplasm

1 Headache associated with intracranial neoplasm is typically

diffuse; nonpulsating; associated with nausea and vomiting;and worsened by physical activity, Valsalva maneuver,

coughing, and sneezing

2 Focal signs may be present, influenced by location and size of

the tumor as well as by the presence of elevated intracranialpressure

3 The incidence of intracranial neoplasms is unaffected by

pregnancy, but it is not unusual for symptomatology to firstappear at this time due to increased extracellular fluid

accumulation There is a significant hormonal influence oncertain tumors, such as pituitary adenomas and meningiomas,which leads to increased growth during pregnancy

3 Abrupt termination of chronic opioid therapy, corticosteroids,

tricyclic antidepressants, and nonsteroidal anti-inflammatory

G Preeclampsia

1 Headache is one of the diagnostic criteria for severe

preeclampsia Headache associated with preeclampsia ischaracterized by bilateral, pulsating pain, aggravated by

physical activity, and accompanied by hypertension and

proteinuria Visual disturbances, including blurred vision and

scotomata, may be present It is not unusual to be asked by

an obstetrician to evaluate a woman with headache 4 to 5 days postpartum, with a presumed diagnosis of PDPH, who, upon careful history, does not require an EBP but requires immediate magnesium therapy and additional management of severe preeclampsia.

1 Headache due to meningitis is characterized by diffuse,

progressively worsening pain In addition, there is often fever,nuchal rigidity, nausea and vomiting, and photophobia

symptoms and signs are similar MRI scanning is required tomake the diagnosis, which should be made as early as possible.22Outcome is improved when treatment to control hypertension and

K Spontaneous intracranial hypotension

The presentation is the same as in patients with PDPH butwithout a history of prior regional anesthesia.26 Dural tears,which are the presumed etiology, most often occur in thoracicdermatomes The diagnosis is confirmed by CT myelography,which can also help identify the level of the CSF leak.27

L Lactation headache

Headache in association with lactation has most often beendescribed in women with prior migrainous headache.28 Increasedvasopressin levels that accompanied breastfeeding has beendescribed in a woman who had repeated headaches while nursing,suggesting that the hormonal changes associated with

breastfeeding may be causative.29 Headache has been described

in association with postpartum breast engorgement.28

Not all postdelivery headaches are due to dural puncture in patients who have received neuraxial anesthesia.

A neurologic examination should be performed before therapy for PDPH is instituted and an abnormality should prompt an evaluation

to rule out other intracranial pathology.

VI. Prevention and treatment of postdural puncture headache after

accidental dural puncture

A Bed rest Bed rest will provide symptomatic relief of PDPH.

prolonging the duration of bed rest after dural puncture

decreases the likelihood of headache Early ambulation after dural puncture should be encouraged, and patients with an established headache should ambulate as much as possible due to the risk of thrombotic disease in the pregnant patient.

B Hydration Despite the widespread enthusiasm for aggressive

hydration after dural puncture, there is only one study of fluidsupplementation after dural puncture that showed no evidencethat it decreased the incidence of PDPH.31

C Prone position The prone position can relieve headache in some

patients with PDPH, but there are no published studies supportingthis practice Presumably, increased intraabdominal pressuretranslocates CSF from the lumbar spine to the intracranial

compartment The prone position may be worthwhile in patientswhose surgical incision does not prevent this position

D Abdominal binder A single study suggested that an abdominal

binder prevents the development of PDPH.32 It may providesymptomatic relief by the same mechanism as prone positioning.Again, this may not be feasible in patients with an abdominalincision

E Caffeine A study of 41 patients with headache unresponsive to

conservative measures demonstrated that IV caffeine 500 mg led

to permanent resolution of symptoms in 70% of subjects.33 Thesmall size of the study and the lack of a control group cast doubt

on the effectiveness of this therapy Additionally, caffeine is

freely excreted into breast milk but is not associated with reports

of adverse neonatal outcomes It has been linked to maternaltoxicity, including seizures and cardiac dysrhythmias Because IVcaffeine is unavailable in many hospitals, the use of oral caffeine

has been proposed as a substitute However, the widespread

recommended

G Corticosteroids/adrenocorticotropic hormone A number of

case reports have suggested a therapeutic role for corticosteroids

dose hydrocortisone reduced the severity of PDPH compared toplacebo.38 Another randomized study could not demonstrate anybenefit from ACTH administration.39 A recent review concludedthat cosyntropin reduced the incidence of PDPH of any severity

or ACTH A single randomized study demonstrated that high-by nearly half, based on the results of only one randomized

trial.40

H Pregabalin and gabapentin Both agents were shown to provide

more effective relief than acetaminophen in a series of orthopedicsurgery patients that developed PDPH; pregabalin 100 mg

administered every 8 hours was the most effective agent.41

I Acupuncture In a recent study, five patients with PDPH

unresponsive to conservative measures were successfully treatedwith acupuncture None required EBP.42

J Intrathecal saline Injection of 10 mL preservative-free saline

through the Tuohy needle after accidental dural puncture has beenshown to decrease the incidence of headache from 62% to 32%.Injection of normal saline through an intrathecal catheter, placedafter accidental dural puncture, appeared to decrease headache as

K Intrathecal catheter After accidental dural puncture during

attempted epidural placement, a catheter can be placed into thesubarachnoid space to provide continuous spinal anesthesia

Some studies have suggested that this technique will reduce theincidence of subsequent PDPH.44 This result has not been

demonstrated consistently, perhaps because of differing durations

of subarachnoid catheterization in the various studies.45 Onestudy showed an improvement when the catheter remained inplace for 24 hours after delivery.46 Subsequent studies have

shown no effect47 or a decreased incidence of PDPH48,49 aftersubarachnoid catheterization Although the effect of subarachnoidcatheterization on subsequent development of PDPH may beunclear, this will eliminate the possibility of a second accidentaldural puncture during an attempt to resite the epidural at anotherlevel If a spinal catheter is placed, it is critical to maintain the

sterility of the catheter It is also imperative that all anesthetic

providers are aware of the presence of a labeled subarachnoid catheter to prevent the injection of large (epidural) doses of local anesthetic and high or total spinal anesthesia.

Unfortunately, discontinuation of the infusion usually leads torecurrence of the headache This technique may be useful in

patients who refuse EBP, providing symptomatic relief until thedural puncture resolves spontaneously

N Epidural blood patch The gold standard for the treatment of

PDPH is EBP, with early reports suggesting a success rate