Pneumocephalus After Lumbar Epidural Steroid Injection: A Case Report and Review of the Literature Aubrey V. Verdun, MD,* Steven P. Cohen, MD,† Bryan S. Williams, MD,‡ and Robert W. Hurley MD, PhD§ Pneumocephalus may occur after inadvertent injection of air into the subarachnoid space while performing epidural anesthesia using a loss-of-resistance technique with air in the syringe. We report a case of pneumocephalus after an interlaminar epidural steroid injection using the loss-of-resistance to air technique. In this report, we examine the etiology, the expected course of symptoms, and resolution, as well as treatment, of pneumocephalus following a systematic literature review. (A&A Case Reports. 2014;3:9–13.)
E
pidural steroid injections are a mainstay in the treatment of radicular pain. These procedures have a low incidence of adverse events and may provide symptomatic pain relief for patients with extremity pain due to a herniated disk, chemical irritation of a nerve root, foraminal stenosis, and central canal stenosis.1 Pneumocephalus is an uncommon complication that can occur after dural puncture.2 Prompt recognition, treatment, and patient reassurance are essential components of successful management. We report a case of pneumocephalus occurring after an inadvertent dural puncture during an interlaminar lumbar epidural steroid injection for bilateral lower extremity pain related to spinal pathology. Patient consent was not obtained; however, consent to publish the patient information was obtained from the University of Florida IRB after review of the manuscript.
CASE DESCRIPTION
A male patient in his late 70s presented with complaints of bilateral lower extremity pain. His symptoms were consistent with the findings on magnetic resonance imaging including central spinal stenosis from the ligamentum flavum hypertrophy of T11 through S1 and radiculopathy from a herniated nucleus pulposus at L4-L5 contacting the descending L5 and S1 nerve roots. His body mass index was within the normal range. He was referred to the pain clinic for conservative management, including lumbar epidural steroid injections. The patient had previously received 2 interlaminar epidural injections separated by 3 months with good relief of his symptoms.
Procedure
With the patient in the prone position, the L4-L5 interlaminar space was identified under fluoroscopy, and an 18-gauge From the *Department of Pain Medicine, Walter Reed National Military Medical Center, Bethesda; †Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University, Baltimore; ‡Department of Anesthesiology, Kaiser Permanente, Gaithersburg, Maryland; and §Department of Anesthesiology, University of Florida, Gainesville, Florida. Accepted for publication January 17, 2014. Funding: Division of Pain Medicine. The authors declare no conflicts of interest. Address correspondence to Robert W. Hurley, MD, PhD, Department of Anesthesiology, Division of Pain Medicine, University of Florida, 1600 SW Archer Rd., Rm M-500, Gainesville, FL 32607. Address e-mail to [email protected]. Copyright © 2014 International Anesthesia Research Society DOI: 10.1213/XAA.0000000000000055
July 1, 2014 • Volume 3 • Number 1
Tuohy needle was advanced into the ligamentum flavum under an anterior–posterior fluoroscopic view. The needle was advanced through the ligament into the epidural space under lateral fluoroscopy using intermittent verification for “loss-of-resistance” (LOR) with an air-filled (approximately 4 mL) glass syringe. After the LOR to 1 to 2 mL air, cerebrospinal fluid was noted in the syringe, and it was concluded that a dural puncture had occurred. The needle was withdrawn, repositioned, and advanced approximately 1 cm cephalad within the same interspace. Epidural entrance was confirmed with LOR to air (2–3 mL). Cerebrospinal fluid was not present at the needle hub or on aspiration. Next, a mixture of 0.25% bupivacaine (1 mL) and 80 mg (2 mL) of particulate methylprednisolone was injected into the epidural space. The extension tubing was cleared of medication with saline injection. The needle was restyleted and removed. After the procedure, the patient walked accompanied by the resident physician to the recovery room. Although the procedure was initially well tolerated, within 15 minutes the patient began to complain of nausea and vomited repeatedly. After the first bout of emesis, the patient reported a severe headache and visual disturbances. The headache was sharp and nonpositional in nature, described as “the worst headache of my life.” The patient had no mental status changes, hemodynamic instability, respiratory depression or cranial nerve pathology. Supplemental oxygen was administered via nasal cannula and IV access was obtained and the patient received antiemetics (ondansetron 4 mg IV), analgesics (fentanyl 100 μg IV), and a fluid bolus of 500 mL normal saline. The differential diagnosis included intracranial hemorrhage, pneumocephalus, subarachnoid hemorrhage, subdural hematoma, and postdural puncture headache (PDPH), and the patient was immediately taken to the computed tomography (CT) suite. The imaging revealed air in the subarachnoid space surrounding the rostral extent of the cervical spinal cord and within the third and lateral ventricles, with no signs of uncal herniation, or epidural, subdural, subarachnoid, or intraparenchymal bleeding, thereby confirming the diagnosis of pneumocephalus (column 1; Fig. 1, A–D). On returning from the CT scan, the patient continued to complain of severe headache and nausea refractory to medications, including fentanyl, ondansetron, metoclopramide, and promethazine. After reviewing the images and lack of symptom resolution, the patient was admitted for observation and management. He was maintained in a head-down (10°) supine position, was given supplemental oxygen to breathe via facemask, and cases-anesthesia-analgesia.org
9
0.5 hour
18 hours
2 weeks
A
B
C
D
Figure 1. Computed tomography of the brain at 30 minutes (column 1), 18 hours (column 2), and 14 days (column 3) after epidural procedure. Symptom resolution occurred at 18 hours. Images were obtained at the level of the (A) lateral ventricles, (B) midbrain, (C) cerebellum, and (D) rostral spinal cord/medulla. White arrows point to intracranial or intrathecal air.
was given maintenance IV fluids until symptom resolution. Eighteen hours after the procedure, the patient’s headache and nausea resolved. A repeat CT scan at that time revealed a modest reduction in the air in the ventricles (column 2; Fig. 1, A–C) and absence of air in the subarachnoid space around the rostral spinal cord (Fig. 1D). The patient was discharged 24 hours after the procedure with complete resolution of pneumocephalus-related symptoms. Of note, his initial presenting pain symptoms of radiculopathy were also reduced. Two weeks after admission, the patient (at his request) had another CT scan of his head for monitoring purposes. These images revealed resolution of intracranial and intrathecal air (column 3; Fig. 1, A–D). He returned to the pain clinic 12 weeks later for a repeat interlaminar lumbar epidural steroid injection that was performed without complication.
DISCUSSION Literature Review
Relevant keywords (“pneumocephalus,” “epidural,” “neuraxial,” “headache”) were used to design a search strategy of the published literature (“pneumocephalus” and “epidural”
10 cases-anesthesia-analgesia.org
or “pneumocephalus” and “neuraxial” or “pneumocephalus” and “headache”). No language restrictions were applied to the search. The Medline (PubMed, 1919–2013) and Google Scholar (1919–2013) databases were used for the literature search. This yielded 2590 articles. Articles involving intentional injection of air into the neuraxis, intentional dura entry, surgical manipulation, medical causes, or idiopathic causes of pneumocephalus were excluded. These were reviewed by the author (RWH) resulting in 22 articles describing 26 cases of pneumocephalus after an inadvertent dural puncture during an epidural needle-based procedure (Table 1). Treatment of symptomatic pneumocephalus described in the articles in the literature review included bed rest with the head of the bed lowered slightly, hemodynamic and volume support as needed, and symptomatic pain and nausea relief with medications. The addition of high-concentration oxygen therapy in an attempt to reduce the partial pressure of nitrogen in the blood hastening the systemic absorption of intraventricular nitrogen3 has been demonstrated to accelerate the resolution of intracranial air collections.4–6 More aggressive oxygen therapies such as hyperbaric oxygen therapy are unlikely to be needed and may result in an increased tension pneumocephalus.7–9 In the current case, the likely source of the pneumocephalus was the direct injection of air through the dural puncture with the LOR to air. Although the use of LOR to air technique is a common technique used for the identification of the epidural space,10–12 it has been associated with an increased risk of inadvertent dural puncture12–14 and an increased risk of headache and pneumocephalus if a dural puncture occurs.15 For instance, Aida et al.15 describe in a case series of 3730 patients receiving epidural injections for chronic pain that LOR with air was associated with significantly more frequent incidence of pneumocephalus (94%) than that after LOR to saline (0%). In the literature reviewed, headache associated with pneumocephalus after an epidural procedure when the LOR to air technique was used was reported in 22 cases, while in 3 cases the LOR technique was not reported and in 1 case the hanging drop technique was used (Table 1). Eleven cases reported nonposturalrelated headaches, 2 cases reported postural headaches, and the remaining cases either did not report postural effects or were unclear in the positional dependence. In 5 cases, headache symptoms resolved before the resolution of the pneumocephalus, while there were no cases in which the symptoms lasted longer than the pneumocephalus. In 21 cases, imaging after the initial diagnostic CT scan was not obtained. The literature describing pneumocephalus-related headache is inconsistent regarding time to onset, the duration and time to resolution of symptoms, and/or recommendations to avoid this complication. For example, symptom onset was highly variable from minutes after the LOR to hours to days (Table 1). Similarly, symptom resolution was also variable; however, patients with headaches resulting from inadvertent dural puncture as part of epidural catheter placement for labor analgesia or the treatment of PDPH appeared to have headaches for longer durations than those who had procedures for the treatment of pain or to provide surgical anesthesia. This may reflect misattribution of the
A & A case reports
Table 1. Procedures and Proposed Mechanisms for Previously Reported Pneumocephalus Resulting from Epidural Interventions Indication for Author(s) procedure Pain Abram and Cherwenka30
Obstetric analgesia
Epidural steroid injection; location—lumbar; LOR—air 2 cases
Guarino and Wright22
Epidural steroid injection; location—lumbar; LOR—air
Hawley et al.2
Epidural steroid injection; location—lumbar; LOR—air
Simopoulos and PeetersAsdourian31
Epidural steroid injection; location—cervical; LOR hanging drop in seated position Epidural steroid injection; location—cervical; LOR –air in seated position
Stauber et al.32
Therapeutic blood patch
Procedure technique
Hutton et al.33
Epidural steroid injection; location—umbar; LOR—air
Nolan et al.34
Epidural steroid injection; location—lumbar; LOR—not listed
Venkat35
Epidural steroid injection; location—unknown; LOR—not listed
Kawamata et al.16
Epidural blood patch LOR—air
Krisanda and Laucks36
Epidural blood patch LOR—air
Hurtado and Clarkson17
Epidural blood patch; LOR—air
Ash et al.37
Epidural blood patch; LOR—air
Ahlering and Brodsky38
Epidural catheter placement; LOR—air (2 cases) Epidural catheter placement; LOR—air
Sherer et al.39
Lucas et al.40
Epidural catheter placement; LOR—air
Symptom(s) and onset time
Pneumocephalus resolution Unknown, no follow-up imaging
Case 1: Sx: headache (postural); Onset: 20 min after procedure. Case 2: Sxs: headache (± postural), nausea, vomiting; Onset: 1 h after procedure Sxs: headache (nonpostural), Unknown, no follow-up generalized weakness, tongue imaging and oral numbness, and “sharpness” behind her eye; Onset: 20 min following procedure Sxs: headache (postural or Air: 6 d nonpostural not specified) and esophoria with left gaze; Onset: “within” hours of the procedure Sxs: headache (nonpostural), Unknown, no follow-up shoulder pain, nausea; imaging obtained Onset: immediately following procedure Sx: cardiopulmonary arrest 1d requiring resuscitation and prolonged intubation
Sxs: temporary loss of consciousness followed by headache (postural or nonpostural not specified) and nausea; Onset: immediate Sxs: headache (nonpostural), nausea, vomiting, and photophobia; Onset: 24 h after procedure Sxs: headache (postural or nonpostural not specified), nausea, and vomiting; Onset: 30 min after procedure Sx: headache (nonpostural), scapular pain; Onset: 30 min after procedure Sxs; headache (postural or nonpostural not specified) and nausea; Onset: immediate Sx: headache (postural or nonpostural not specified); Onset: immediate Sxs: headache (nonpostural), nausea, and vomiting; Onset: immediate Sx: headache (± postural); Onset: immediate Sx: nonresponsive, fixed and dilated pupils; Onset: approximately 2 h after procedure Sx: headache (nonpostural); Onset: immediate
Unknown, no follow-up imaging
Symptom resolution 1 to 3 h
Approximately 1 wk
Approximate hours not specified other than
E
pidural steroid injections are a mainstay in the treatment of radicular pain. These procedures have a low incidence of adverse events and may provide symptomatic pain relief for patients with extremity pain due to a herniated disk, chemical irritation of a nerve root, foraminal stenosis, and central canal stenosis.1 Pneumocephalus is an uncommon complication that can occur after dural puncture.2 Prompt recognition, treatment, and patient reassurance are essential components of successful management. We report a case of pneumocephalus occurring after an inadvertent dural puncture during an interlaminar lumbar epidural steroid injection for bilateral lower extremity pain related to spinal pathology. Patient consent was not obtained; however, consent to publish the patient information was obtained from the University of Florida IRB after review of the manuscript.
CASE DESCRIPTION
A male patient in his late 70s presented with complaints of bilateral lower extremity pain. His symptoms were consistent with the findings on magnetic resonance imaging including central spinal stenosis from the ligamentum flavum hypertrophy of T11 through S1 and radiculopathy from a herniated nucleus pulposus at L4-L5 contacting the descending L5 and S1 nerve roots. His body mass index was within the normal range. He was referred to the pain clinic for conservative management, including lumbar epidural steroid injections. The patient had previously received 2 interlaminar epidural injections separated by 3 months with good relief of his symptoms.
Procedure
With the patient in the prone position, the L4-L5 interlaminar space was identified under fluoroscopy, and an 18-gauge From the *Department of Pain Medicine, Walter Reed National Military Medical Center, Bethesda; †Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University, Baltimore; ‡Department of Anesthesiology, Kaiser Permanente, Gaithersburg, Maryland; and §Department of Anesthesiology, University of Florida, Gainesville, Florida. Accepted for publication January 17, 2014. Funding: Division of Pain Medicine. The authors declare no conflicts of interest. Address correspondence to Robert W. Hurley, MD, PhD, Department of Anesthesiology, Division of Pain Medicine, University of Florida, 1600 SW Archer Rd., Rm M-500, Gainesville, FL 32607. Address e-mail to [email protected]. Copyright © 2014 International Anesthesia Research Society DOI: 10.1213/XAA.0000000000000055
July 1, 2014 • Volume 3 • Number 1
Tuohy needle was advanced into the ligamentum flavum under an anterior–posterior fluoroscopic view. The needle was advanced through the ligament into the epidural space under lateral fluoroscopy using intermittent verification for “loss-of-resistance” (LOR) with an air-filled (approximately 4 mL) glass syringe. After the LOR to 1 to 2 mL air, cerebrospinal fluid was noted in the syringe, and it was concluded that a dural puncture had occurred. The needle was withdrawn, repositioned, and advanced approximately 1 cm cephalad within the same interspace. Epidural entrance was confirmed with LOR to air (2–3 mL). Cerebrospinal fluid was not present at the needle hub or on aspiration. Next, a mixture of 0.25% bupivacaine (1 mL) and 80 mg (2 mL) of particulate methylprednisolone was injected into the epidural space. The extension tubing was cleared of medication with saline injection. The needle was restyleted and removed. After the procedure, the patient walked accompanied by the resident physician to the recovery room. Although the procedure was initially well tolerated, within 15 minutes the patient began to complain of nausea and vomited repeatedly. After the first bout of emesis, the patient reported a severe headache and visual disturbances. The headache was sharp and nonpositional in nature, described as “the worst headache of my life.” The patient had no mental status changes, hemodynamic instability, respiratory depression or cranial nerve pathology. Supplemental oxygen was administered via nasal cannula and IV access was obtained and the patient received antiemetics (ondansetron 4 mg IV), analgesics (fentanyl 100 μg IV), and a fluid bolus of 500 mL normal saline. The differential diagnosis included intracranial hemorrhage, pneumocephalus, subarachnoid hemorrhage, subdural hematoma, and postdural puncture headache (PDPH), and the patient was immediately taken to the computed tomography (CT) suite. The imaging revealed air in the subarachnoid space surrounding the rostral extent of the cervical spinal cord and within the third and lateral ventricles, with no signs of uncal herniation, or epidural, subdural, subarachnoid, or intraparenchymal bleeding, thereby confirming the diagnosis of pneumocephalus (column 1; Fig. 1, A–D). On returning from the CT scan, the patient continued to complain of severe headache and nausea refractory to medications, including fentanyl, ondansetron, metoclopramide, and promethazine. After reviewing the images and lack of symptom resolution, the patient was admitted for observation and management. He was maintained in a head-down (10°) supine position, was given supplemental oxygen to breathe via facemask, and cases-anesthesia-analgesia.org
9
0.5 hour
18 hours
2 weeks
A
B
C
D
Figure 1. Computed tomography of the brain at 30 minutes (column 1), 18 hours (column 2), and 14 days (column 3) after epidural procedure. Symptom resolution occurred at 18 hours. Images were obtained at the level of the (A) lateral ventricles, (B) midbrain, (C) cerebellum, and (D) rostral spinal cord/medulla. White arrows point to intracranial or intrathecal air.
was given maintenance IV fluids until symptom resolution. Eighteen hours after the procedure, the patient’s headache and nausea resolved. A repeat CT scan at that time revealed a modest reduction in the air in the ventricles (column 2; Fig. 1, A–C) and absence of air in the subarachnoid space around the rostral spinal cord (Fig. 1D). The patient was discharged 24 hours after the procedure with complete resolution of pneumocephalus-related symptoms. Of note, his initial presenting pain symptoms of radiculopathy were also reduced. Two weeks after admission, the patient (at his request) had another CT scan of his head for monitoring purposes. These images revealed resolution of intracranial and intrathecal air (column 3; Fig. 1, A–D). He returned to the pain clinic 12 weeks later for a repeat interlaminar lumbar epidural steroid injection that was performed without complication.
DISCUSSION Literature Review
Relevant keywords (“pneumocephalus,” “epidural,” “neuraxial,” “headache”) were used to design a search strategy of the published literature (“pneumocephalus” and “epidural”
10 cases-anesthesia-analgesia.org
or “pneumocephalus” and “neuraxial” or “pneumocephalus” and “headache”). No language restrictions were applied to the search. The Medline (PubMed, 1919–2013) and Google Scholar (1919–2013) databases were used for the literature search. This yielded 2590 articles. Articles involving intentional injection of air into the neuraxis, intentional dura entry, surgical manipulation, medical causes, or idiopathic causes of pneumocephalus were excluded. These were reviewed by the author (RWH) resulting in 22 articles describing 26 cases of pneumocephalus after an inadvertent dural puncture during an epidural needle-based procedure (Table 1). Treatment of symptomatic pneumocephalus described in the articles in the literature review included bed rest with the head of the bed lowered slightly, hemodynamic and volume support as needed, and symptomatic pain and nausea relief with medications. The addition of high-concentration oxygen therapy in an attempt to reduce the partial pressure of nitrogen in the blood hastening the systemic absorption of intraventricular nitrogen3 has been demonstrated to accelerate the resolution of intracranial air collections.4–6 More aggressive oxygen therapies such as hyperbaric oxygen therapy are unlikely to be needed and may result in an increased tension pneumocephalus.7–9 In the current case, the likely source of the pneumocephalus was the direct injection of air through the dural puncture with the LOR to air. Although the use of LOR to air technique is a common technique used for the identification of the epidural space,10–12 it has been associated with an increased risk of inadvertent dural puncture12–14 and an increased risk of headache and pneumocephalus if a dural puncture occurs.15 For instance, Aida et al.15 describe in a case series of 3730 patients receiving epidural injections for chronic pain that LOR with air was associated with significantly more frequent incidence of pneumocephalus (94%) than that after LOR to saline (0%). In the literature reviewed, headache associated with pneumocephalus after an epidural procedure when the LOR to air technique was used was reported in 22 cases, while in 3 cases the LOR technique was not reported and in 1 case the hanging drop technique was used (Table 1). Eleven cases reported nonposturalrelated headaches, 2 cases reported postural headaches, and the remaining cases either did not report postural effects or were unclear in the positional dependence. In 5 cases, headache symptoms resolved before the resolution of the pneumocephalus, while there were no cases in which the symptoms lasted longer than the pneumocephalus. In 21 cases, imaging after the initial diagnostic CT scan was not obtained. The literature describing pneumocephalus-related headache is inconsistent regarding time to onset, the duration and time to resolution of symptoms, and/or recommendations to avoid this complication. For example, symptom onset was highly variable from minutes after the LOR to hours to days (Table 1). Similarly, symptom resolution was also variable; however, patients with headaches resulting from inadvertent dural puncture as part of epidural catheter placement for labor analgesia or the treatment of PDPH appeared to have headaches for longer durations than those who had procedures for the treatment of pain or to provide surgical anesthesia. This may reflect misattribution of the
A & A case reports
Table 1. Procedures and Proposed Mechanisms for Previously Reported Pneumocephalus Resulting from Epidural Interventions Indication for Author(s) procedure Pain Abram and Cherwenka30
Obstetric analgesia
Epidural steroid injection; location—lumbar; LOR—air 2 cases
Guarino and Wright22
Epidural steroid injection; location—lumbar; LOR—air
Hawley et al.2
Epidural steroid injection; location—lumbar; LOR—air
Simopoulos and PeetersAsdourian31
Epidural steroid injection; location—cervical; LOR hanging drop in seated position Epidural steroid injection; location—cervical; LOR –air in seated position
Stauber et al.32
Therapeutic blood patch
Procedure technique
Hutton et al.33
Epidural steroid injection; location—umbar; LOR—air
Nolan et al.34
Epidural steroid injection; location—lumbar; LOR—not listed
Venkat35
Epidural steroid injection; location—unknown; LOR—not listed
Kawamata et al.16
Epidural blood patch LOR—air
Krisanda and Laucks36
Epidural blood patch LOR—air
Hurtado and Clarkson17
Epidural blood patch; LOR—air
Ash et al.37
Epidural blood patch; LOR—air
Ahlering and Brodsky38
Epidural catheter placement; LOR—air (2 cases) Epidural catheter placement; LOR—air
Sherer et al.39
Lucas et al.40
Epidural catheter placement; LOR—air
Symptom(s) and onset time
Pneumocephalus resolution Unknown, no follow-up imaging
Case 1: Sx: headache (postural); Onset: 20 min after procedure. Case 2: Sxs: headache (± postural), nausea, vomiting; Onset: 1 h after procedure Sxs: headache (nonpostural), Unknown, no follow-up generalized weakness, tongue imaging and oral numbness, and “sharpness” behind her eye; Onset: 20 min following procedure Sxs: headache (postural or Air: 6 d nonpostural not specified) and esophoria with left gaze; Onset: “within” hours of the procedure Sxs: headache (nonpostural), Unknown, no follow-up shoulder pain, nausea; imaging obtained Onset: immediately following procedure Sx: cardiopulmonary arrest 1d requiring resuscitation and prolonged intubation
Sxs: temporary loss of consciousness followed by headache (postural or nonpostural not specified) and nausea; Onset: immediate Sxs: headache (nonpostural), nausea, vomiting, and photophobia; Onset: 24 h after procedure Sxs: headache (postural or nonpostural not specified), nausea, and vomiting; Onset: 30 min after procedure Sx: headache (nonpostural), scapular pain; Onset: 30 min after procedure Sxs; headache (postural or nonpostural not specified) and nausea; Onset: immediate Sx: headache (postural or nonpostural not specified); Onset: immediate Sxs: headache (nonpostural), nausea, and vomiting; Onset: immediate Sx: headache (± postural); Onset: immediate Sx: nonresponsive, fixed and dilated pupils; Onset: approximately 2 h after procedure Sx: headache (nonpostural); Onset: immediate
Unknown, no follow-up imaging
Symptom resolution 1 to 3 h
Approximately 1 wk
Approximate hours not specified other than
