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 Table of Contents  
Year : 2017  |  Volume : 31  |  Issue : 3  |  Page : 194-196

Pneumocephalus after epidural injection: A rare complication of a common procedure

Department of Anaesthesia and Critical Care, Sri Aurobindo Institute of Medical Sciences, Indore, Madhya Pradesh, India

Date of Web Publication18-Jan-2018

Correspondence Address:
Sohail Sachdeva
H. No 182, Sector-7, Urban Estate, Karnal - 132 001, Haryana
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijpn.ijpn_75_17

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Our patient with prolapsed intervertebral disc at L3–L4 was given lumbar epidural steroid injection using loss of resistance to air technique with 3 ml of air. After 5–6 h, she developed severe frontal and temporal headache with few episodes of nonprojectile vomiting, followed by disorientation and agitation. An urgent magnetic resonance imaging was done which revealed pneumocephalus.

How to cite this article:
Sachdeva S, Sanwatsarkar S, Maheshwari M, Singh P. Pneumocephalus after epidural injection: A rare complication of a common procedure. Indian J Pain 2017;31:194-6

How to cite this URL:
Sachdeva S, Sanwatsarkar S, Maheshwari M, Singh P. Pneumocephalus after epidural injection: A rare complication of a common procedure. Indian J Pain [serial online] 2017 [cited 2020 Oct 21];31:194-6. Available from: https://www.indianjpain.org/text.asp?2017/31/3/194/223673

  Introduction Top

Epidural injection is a widely used procedure for relief of symptoms associated with prolapsed intervertebral disc (PIVD). Several methods have been employed for identification of the epidural space, the most common being “loss of resistance to air” (LORA).[1] Although widely used, it comes with a rare complication of inadvertent injection of air in subdural/subarachnoid [2],[3] space, which can lead to symptoms of increased intracranial pressure. With the help of radiological imaging, location of air in cranium can guide us to locate the source of air introduction through subdural or subarachnoid space.

  Case Report Top

A 50-year-old female with a chief complaint of pain in the back and lower limb was diagnosed to have PIVD at lumbar 3rd–4th level. The patient had a history of migraine for the past 1 year, for which she was taking aspirin SOS.

She had received two epidural injections and was posted for the third epidural injection. Preanesthetic checkup was done, and the patient was conscious and well-oriented to time place and person with motor and sensory functions intact. The patient was prepared for epidural injection with 80 mg kenacort + 0.5% bupivacaine 4 cc + 6 cc distilled water. Epidural space was identified in the first attempt using “LORA” (3 ml air) technique and the procedure concluded uneventfully. Following the procedure, the patient was kept in sitting position for 10 min, made supine, and shifted to recovery unit. Six hours later, the patient developed severe frontal and temporal headache which was independent of postural change, associated with 2–3 episodes of nonprojectile vomiting. Patient's condition worsened and she became irritated, disoriented, and agitated; however, patient's vitals remained within normal limits. An urgent magnetic resonance imaging was done which revealed multiple air emboli [Figure 1] and [Figure 2].
Figure 1: Midsagittal T2-weighted magnetic resonance imaging image showing multiple air foci in lateral ventricle at level of basal ganglia

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Figure 2: T1-weighted axial magnetic resonance imaging image showing air in subarachnoid space

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The patient was shifted to Intensive Care Unit (ICU) immediately, and symptomatic treatment was started. Humidified oxygen at 8–10 L via a face mask and midazolam infusion was started to manage agitation along with analgesics, antiemetics, and antibiotics. Vitals remained stable throughout ICU stay, and the patient maintained 100% oxygen saturation. Midazolam infusion was tapered gradually and discontinued on the 3rd day. The patient was totally conscious and well-oriented by the 5th day. On the 10th day, a repeat computed tomography (CT) scan was done, which showed no air emboli. The patient was discharged without any neurological deficit on the 11th day.

  Discussion Top

Pneumocephalus (PC) basically means air/gas in the cranial cavity. Although common in neurosurgery and neuroradiology,[4],[5] it is rarely seen after epidural injection as a consequence of unintentional dura puncture, resulting from the introduction of air into subarachnoid/subdural space and subsequent cranial migration.[2],[3]

Incidence of PC is unknown and only few cases are reported per year.[6] Complication related to procedure per se are hypotension, postdural puncture headache (PDPH), dizziness, transient paraplegia, and PC.

Epidural space can be identified using loss of resistance technique (using air or saline), detection of negative pressure (hanging drop and inflated balloon), besides other methods such as ultrasonography guided and fluoroscopy guided. LORA and loss of resistance to saline (LORS) are commonly used [7],[8] and carry with them their own advantages and disadvantages. Using LORS, space can be well appreciated but may dilute local anesthetic solution and it is difficult to ascertain subarachnoid puncture. On the other hand, LORA may lead to false-positive results because of air being compressible.[9],[10] Other complications related to LORA technique were compression of nerve roots and spinal cord, subcutaneous emphysema, incomplete analgesia, paresthesia, PC, hypotension, bradycardia, apnea.[11]

Air can inadvertently enter the cranium through subdural/subarachnoid space during epidural space identification since in our case there was no cerebrospinal fluid leakage; hence, ruling out the possibility of subarachnoid puncture, the possible explanation for PC could be that air might have entered the cranium through subdural space. Subdural space refers to space between dura and arachnoid mater, filled with small volume of serous fluid, and connected to cranium via second sacral vertebrae and the possible route for air to migrate intracranially.[12],[13],[14]

Sign and symptoms following migration of air comprise mainly of headache.[10],[15] Other signs of space-occupying lesions, such as nausea and vomiting, disorientation, agitation, decreased level of consciousness, seizures, and dysarthria, depend on amount and spread of air.[16],[17] In our case, 3 ml of air was used for space identification, and air volume as low as 2 ml can cause PC.[18]

It is important to diagnose PC early on the basis of clinical features and distinguish it from PDPH. In our case, headache was abrupt in onset (within 3–4 h), localized to frontotemporal region, and independent of posture, whereas in PDPH, headache characteristically occurs 24–48 h after dural puncture and is exacerbated by upright posture and relieved on lying down.[19] Nevertheless, diagnosis is best confirmed radiologically.

PC usually resolves spontaneously with symptomatic treatment. Oxygen supplementation in the supine position to accelerate absorption of intracranial air and rapid denitrogenation,[20],[21] prophylactic antibiotics, analgesics, and adequate hydration. Our patient was also taken on midazolam infusion to curb her agitation and restlessness. The patient was discharged on the 11th day when she recovered clinically and repeated CT scan which revealed no air foci.

PC can be prevented using saline instead of air, or if at all, air is to be used maximum 2 ml should be used. Decreasing the number of attempts and avoiding coughing and deep breaths (creates negative intrathoracic pressure), vigilant monitoring is among other essentials.

Although these steps would prevent a rare complication such as PC, the question arises; is blind epidural technique a good choice for steroid injection? Limitations regarding blind epidural technique are culminating with evidence from various studies.[22] There is no prediction about the direction and flow of drug to pathological site and incorrectly placed needles, this in contrast with usage of image modalities, fluoroscopic methods, use of dye to confirm adequate and targeted spread of drug, thus decreasing the chances of failure, patient discomfort, and complications. An incidental finding in our case was that the patient was in sitting position after procedure to help in concentrating the drug to required site, which also led to migration of air cranially. This case was an eye opener for my team, and yet it should be for all of us practicing pain management. It is highly recommended to utilize image modalities for the best outcome.

  Conclusion Top

Thus, we conclude that although not frequent, PC, if occurs, carries risk of severe headache and neurological complications. Preference should be given to LORS; air if used should be minimized and not used at all in case of dura puncture. A high index of suspicion should be kept in mind if symptoms appear within hours of procedure and diagnosis should be confirmed radiologically.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Harrell LE, Drake ME, Massey EW. Pneumocephaly from epidural anesthesia. South Med J 1983;76:399-400.  Back to cited text no. 1
Wang JC, Tsai SH, Liao WI. Pneumocephalus after epidural anesthesia in an adult who has undergone lumbar laminectomy. J Neurosurg Anesthesiol 2014;26:261-3.  Back to cited text no. 2
Nafiu OO, Urquhart JC. Pneumocephalus with headache complicating labour epidural analgesia: Should we still be using air? Int J Obstet Anesth 2006;15:237-9.  Back to cited text no. 3
Reasoner DK, Todd MM, Scamman FL, Warner DS. The incidence of pneumocephalus after supratentorial craniotomy. Observations on the disappearance of intracranial air. Anesthesiology 1994;80:1008-12.  Back to cited text no. 4
Peterson HO, Kieffer SA. Neuroradiology. Vol. 1. New York: Hayon and Row; 1984. p. 127-30.  Back to cited text no. 5
Hawley JS, Ney JP, Swanberg MM. Subarachnoid pneumocephalus from epidural steroid injection. Headache 2005;45:247-8.  Back to cited text no. 6
de Andrés JA, Gomar C, Calatrava P, Nalda MA. Comparative study of detection methods in epidural anesthesia: Episensor and loss of resistance. Rev Esp Anestesiol Reanim 1990;37:330-4.  Back to cited text no. 7
Mateo E, López-Alarcón MD, Moliner S, Calabuig E, Vivó M, De Andrés J, et al. Epidural and subarachnoidal pneumocephalus after epidural technique. Eur J Anaesthesiol 1999;16:413-7.  Back to cited text no. 8
Davidson JT. Identification of the epidural space. Anesthesiology 1966;27:859.  Back to cited text no. 9
Zaccara G, Muscas GC, Messori A. Clinical features, pathogenesis and management of drug-induced seizures. Drug Saf 1990;5:109-51.  Back to cited text no. 10
Kim YD, Lee JH, Cheong YK. Pneumocephalus in a patient with no cerebrospinal fluid leakage after lumbar epidural block – A case report. Korean J Pain 2012;25:262-6.  Back to cited text no. 11
Ajar AH, Rathmell JP, Mukherji SK. The subdural compartment. Reg Anesth Pain Med 2002;27:72-6.  Back to cited text no. 12
Collier CB. Why obstetric epidurals fail: A study of epidurograms. Int J Obstet Anesth 1996;5:19-31.  Back to cited text no. 13
Reina MA, De Leon Casasola O, López A, De Andrés JA, Mora M, Fernández A, et al. The origin of the spinal subdural space: Ultrastructure findings. Anesth Analg 2002;94:991-5.  Back to cited text no. 14
Katz JA, Lukin R, Bridenbaugh PO, Gunzenhauser L. Subdural intracranial air: An unusual cause of headache after epidural steroid injection. Anesthesiology 1991;74:615-8.  Back to cited text no. 15
Rodrigo P, Garcia JM, Ailagas J. Generalized seizure crisis related to pneumocephalus after inadvertent dural puncture in a obstetric patient. Rev Esp Anestesiol Reanim 1997; 44:247-9.  Back to cited text no. 16
Fedder SL. Air ventriculogram serendipitously discovered after epidural anesthesia. Surg Neurol 1988;30:242-4.  Back to cited text no. 17
Guarino AH, Wright NM. Pneumocephalus after a lumbar epidural steroid injection. Pain Physician 2005;8:239-41.  Back to cited text no. 18
Benzon HT, Linde HW, Molloy RE, Brunner EA. Postdural puncture headache in patients with chronic pain. Anesth Analg 1980;59:772-4.  Back to cited text no. 19
Kim YJ, Baik HJ, Kim JH, Jun JH. Pneumocephalus developed during epidural anesthesia for combined spinalepidural anesthesia. Korean J Pain 2009;22:163-6.  Back to cited text no. 20
Schirmer CM, Heilman CB, Bhardwaj A. Pneumocephalus: Case illustrations and review. Neurocrit Care 2010;13:152-8.  Back to cited text no. 21
Levin JH, Wetzel R, Smuck MW. The importance of image guidance during epidural injections: Rates of incorrect needle placement during non-image guided epidural injections. J Spine 2012;1:113. [doi: 10.4172/2165-7939.1000113].  Back to cited text no. 22


  [Figure 1], [Figure 2]


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