Print version ISSN 0034-7094
Rev. Bras. Anestesiol. vol.54 no.1 Campinas Jan./Feb. 2004
Epidural abscess after patient-controlled epidural analgesia. Case report*
Absceso peridural después de analgesia controlada por el paciente por vía peridural. Relato de caso
Múcio Paranhos de Abreu, TSA, M.D.I; Roberto de Góis Deda, M.D.II; Luis Henrique Cangiani, M.D.III; Hernando Mauro Diógenes Aquino, M.D.II; Jair Ortiz, M.D.IV
IInstrutor do CET/SBA
IIME2 do CET/SBA
IIIME1 do CET/SBA
IVOrtopedista do Centro Médico de Campinas
BACKGROUND AND OBJECTIVES: Epidural analgesia
is often used to control postoperative pain or to manage chronic pain in oncologic
patients. However, it is not free from complications. This case reports a young
healthy female patient submitted to epidural analgesia in patient-controlled
infusion pump, which developed epidural abscess requiring surgical decompression.
CASE REPORT: Female patient, 24 years of age, 56 kg, 1.65 m, physical status ASA I, with history of low back pain and difficulty to bend left thigh, submitted to posterior hip muscles surgical release. Three days after hospital discharge, patient returned referring pain at surgical incision site and during physical therapy. Patient was admitted to hospital and patient-controlled epidural analgesia (PCA) was prescribed to allow physical therapy. Patient was sedated in the operating room with intravenous midazolam (2.5 mg) and fentanyl (25 µg), skin was disinfected and epidural puncture was performed at L3-L4 interspace. After the test dose, 0.75% ropivacaine (75 mg) and fentanyl (100 µg) were injected and an epidural catheter was inserted in the cephalad direction without intercurrences. PCA pump containing 0.9% saline solution (85 ml), 0.5% bupivacaine (25 mg) and fentanyl (500 µg) was installed, with constant 4 ml.h-1 flow and 2 ml bolus at 20-minute intervals. In the 3rd day, patient referred discomfort at catheter insertion site and catheter was removed. There was mild local hyperemia. Twenty-two days later patient returned to hospital with severe lumbosacral movement-limiting pain irradiating to lower limbs. There were no neurological deficits or flogistic signs at puncture site or surgical wound. The hypothesis was epidural abscess confirmed by MRI at L3-L4 (2 x 3 cm). After laminectomy, material culture has revealed staphylococcus aureus. Patient evolved well without neurological sequelae.
CONCLUSIONS: Epidural analgesia often used to control postoperative or chronic pain, although very effective, is not free from severe, although rare complications, such as epidural abscess.
Key Words: ANALGESIA, Postoperative: patient controlled analgesia; COMPLICATIONS: epidural abscess
JUSTIFICATIVA Y OBJETIVOS: La analgesia
peridural frecuentemente es utilizada para el control del dolor pos-operatorio
o para tratamiento del dolor crónico en pacientes oncológicos.
No obstante no está exenta de complicaciones. En este caso, relatamos
la ocurrencia de absceso peridural en una joven paciente, hígida, que
fue sometida a analgesia peridural en bomba de infusión controlada por
la paciente, que presentó absceso peridural, siendo necesaria descompresión
RELATO DE CASO: Paciente de sexo femenino, 24 años, 56 kg, 1,65 m, estado físico ASA I, con historia de lombalgia y dificultad de flexión del muslo izquierdo, fue sometida a cirugía para liberación de la musculatura posterior del cuadril o anca. Tres días después del alta hospitalar retornó al hospital quejándose de dolor en el local de la incisión quirúrgica y durante la realización de los ejercicios fisioterápicos. Fue internada y programada analgesia controlada por la paciente (ACP) por vía peridural, para posibilitar el tratamiento fisioterápico. En el centro quirúrgico fue hecha sedación por vía venosa con midazolam (2,5 mg) y fentanil (25 µg), anti-sepsia de la piel y realizada punción peridural en el espacio L3-L4. Después de la dosis test fueron inyectados ropivacaína a 0,75% (75 mg) y fentanil (100 µg) y pasado catéter peridural en sentido cefálico, sin interocurrencias. Fue instalada bomba de ACP conteniendo solución fisiológica a 0,9% (85 ml), bupivacaína a 0,5% (25 mg) y fentanil (500 µg), programada con flujo constante de 4 ml.h-1 y bolus de 2 ml a cada 20 minutos. En el 3º día la paciente relató incómodo en el local de la inserción del catéter, siendo el mismo retirado. Había discreta hiperemia local. Después de veintidós días, la paciente retornó al hospital con dolor de grande intensidad en la región sacrolumbar con irradiación para los miembros inferiores y limitación de los movimientos. No había deficit neurológico o señales flogísticos en el local de la punción o en la herida operatoria. Fue hecha hipótesis de absceso peridural y la resonancia nuclear magnética confirmó la presencia del mismo en L3-L4 (2 x 3 cm), realizada laminectomia, la cultura del material mostró tratarse de staphilococcus aureus. La paciente evoluyó bien, sin secuela neurológica.
CONCLUSIONES: La analgesia peridural, muchas veces utilizada para el control del dolor pos-operatorio o del dolor crónico, aun cuando muy efectiva, no está libre de complicaciones, aunque raras, como el absceso peridural.
Epidural analgesia is often used to control postoperative pain or to treat chronic pain in oncologic patients. Although not being free from complications, most of them are well-known by anesthesiologists and are easy to control 1,2. Epidural abscess is a severe epidural analgesia complication which, although rare, results in high morbidity and even mortality 1. The incidence of post catheter insertion epidural abscess is still not well defined, varying widely in a study-to-study basis 1,3-5.
A recent study performed in a 1-year period, has shown the incidence of one epidural abscess out of 1930 epidural analgesia's with catheter insertion 1, or an incidence of 0.05%.
Most studies reporting epidural abscess are related to immunodepressed patients, with diabetes mellitus, chronic renal failure or to oncologic patients. In our case, we report epidural abscess in young and healthy female patient submitted to patient-controlled epidural analgesia, which has evolved to surgical decompression.
Female patient, 24 years of age, 56 kg, 1.65 m, physical status ASA I, with history of low back pain and difficulty to bend left thigh, submitted to surgical left hip posterior muscles tendons release.
Patient was under oral contraceptives and was in good general condition at physical evaluation: eupneic, rosy-checked, without cardiac and pulmonary changes at auscultation, heart rate of 69 bpm and BP of 140 x 80 mmHg.
Patient was submitted to general intravenous and inhalational anesthesia without intercurrences being discharged with indication for physical therapy.
Three days after discharge, patient returned to hospital referring pain at surgical incision site and during physical therapy. At surgeon's request, patient was admitted and patient-controlled epidural analgesia (PCA) was scheduled to allow for physical therapy exercises.
After preanesthetic evaluation and 8 hours fast, patient was referred to the operating center for epidural analgesia with catheter. After monitoring and venoclysis, patient was sedated with intravenous midazolam (2.5 mg) and fentanyl (25 µg). Then, with the patient in the sitting position skin was disinfected with 0.5% chlorhexidine digluconate and single median puncture was performed at L3-L4 interspace with 17G Tuohy disposable needle. After positive loss of resistance to air test, 60 mg of 2% lidocaine with epinephrine 1:200,000 (test-dose) were injected, followed by 0.75% ropivacaine (75 mg) and fentanyl (100 µg). Epidural catheter was inserted without intercurrences in the cephalad direction and an occlusive dressing with micropore and gauze was applied over the catheter. PCA pump was installed with 0.9% saline solution (85 ml), 0.5% bupivacaine (25 mg) and fentanyl (500 µg) prepared by the anesthesiologist and set for constant 4 ml.h-1 flow and 2 ml bolus at 20-minute intervals.
Patient evolved without pain at surgical site and was able to perform physical therapy exercises. Approximately 24 hours after epidural analgesia, patient was already referring pain at catheter insertion site. Due to good analgesic effects, lack of flogistic signs at catheter insertion site and absence of fever, neurological deficit or menyngeal signs, catheter was maintained for 82 hours when it was totally removed at patient's request, due to local pain. At evaluation, there was mild hyperemia on catheter insertion orifice without secretions.
Patient was discharged 4 days later with mild low back pain only when exercising.
Twenty-two days later, patient returned to hospital with severe lumbosacral pain irradiating to lower limbs. There were no flogistic signs at puncture site or surgical wound. There was no neurological deficit. Two blood counts were performed at the 8th and 16th day after hospital discharge, which were normal. Patient did nor refer fever, but was extremely agitated due to pain. Clinical treatment was attempted with ketoprofen, tramadol, meperidine and morphine, however without response.
After lab tests (blood count, VHs, Reactive C-Protein and Urine I) a CT image was obtained from the lumbosacral area, which has evidenced intervertebral disk convexity at L5-S1 which, according to the orthopedist, would not justify pain. Abdominal ultrasound and gynecological evaluation were normal. Current leucogram (28 days after epidural analgesia) was already showing mild leucocytosis (14600 leucocytes) shifted to the left (5% rods and 79% segmented), increased reactive C-protein (180 mg.l-1) and hemosedimentation rate of 54 mm at the first hour. The hypothesis was epidural abscess. MRI has confirmed epidural abscess at L3-L4 measuring 2 x 3 cm (Figure 1A and 1B). Patient was submitted to decompressive laminectomy under general anesthesia and antibiotic therapy was started with kephazoline. Material culture has revealed staphylococcus aureus. Wound was maintained opened for second intention healing.
Patient evolved well and was discharged, only returning to the hospital for periodic dressings. There have been no neurological sequelae.
Epidural abscess is a rare complication with an incidence varying from 1/50000 to 1-2/10000 hospital admissions 6. Risk factors for post epidural anesthesia abscesses are related to the presence of diabetes mellitus, chronic renal failure, cancer, steroid therapy, herpes zoster and rheumatoid arthritis 7. In general, early diagnosis is difficult, especially in healthy patients, due to the ambiguous nature of signs and symptoms 8. Progressive catheter insertion site pain irradiating to lower limbs associated to fever is the most common symptom. Lack of muscle strength on extremities, sensory deficit, vesical or intestinal dysfunction and paralysis are also epidural abscess symptoms 6. The presence of neurological deficit helps the diagnosis and MRI is the test of choice to confirm it 9. In our case, patient was classified as ASA I and has only referred slowly progressing pain at catheter insertion site. The lack of fever or neurological deficit has made early diagnosis difficult.
Epidural space may be infected at epidural catheter insertion 10 or through subsequent contamination by three different routes 11: skin contamination and subsequent dissemination via catheter; hematological dissemination; or even by syringe 12 or anesthetic solution 7 contamination.
We have only found in the literature one case of infection during catheter insertion, where the infecting bacteria was also detected in anesthesiologist's nasal swab 10.
Measures to be taken by anesthesiologists to decrease contamination risks during catheter insertion include the use of strictly aseptic techniques, wearing cap, facial mask and sterile gloves worn after thorough hands cleaning.
Patient's skin disinfection should be achieved with adequate bactericide agents and waiting the necessary time for it to be effective. Studies have shown that no microorganism has grown in culture after being exposed to 0.5% chorhexidine with 80% ethanol 6.
A different study has shown that, in spite of the strict compliance with the aseptic technique, epidural or spinal puncture needles may be contaminated by several agents which, once taken to the epidural or spinal space, may lead to clinical infection 13.
Epidural analgesic solution contamination may also favor epidural space infection 6. Recent studies have shown increased infection risk when analgesic solution infusion is administered through 60 ml syringes as compared to solutions administered through analgesic solution bags in closed infusion system 14.
In our case, which was unique in our center, all cleaning and disinfection measures were strictly followed: wearing of cap, facial mask and sterile gloves after thorough hands washing, as well as patient's skin disinfection with 5% chlorhexidine performed in the operating center. There have been no technical difficulties for epidural puncture or catheter insertion, being performed a single puncture without intercurrences.
Special attention is to be paid to asepsis during catheter or analgesic solution manipulation while patient is with the epidural catheter, because infection may appear during the whole admission period.
Staphylococcus aureus is the most common microorganism found in epidural abscess cultures 1,15.
Early diagnosis, epidural space decompression and debridement associated to adequate antibiotic therapy contribute to successful epidural abscess treatment 16,17.
In spite of major benefits obtained with epidural catheter to control postoperative pain, risks, although rare such as epidural abscess, cannot be overlooked. If they are not promptly treated as from epidural abscess, other complications may appear, such as severe and irreversible medullary compressions and nervous injuries. These are also rare complications 6. In addition, epidural abscesses generate costs both for the patient and the hospital: prolonged hospital stay; need for expensive tests, such as MRI; surgical epidural space decompression and debridement; antibiotic therapy; not to talk about the risk for irreversible neurological sequelae.
The adherence to rigorously aseptic techniques for epidural catheter insertion performed in clean hospital area (operating center), as well as the careful and aseptic catheter and analgesic solution manipulation, contribute to prevent this feared complication which is the epidural abscess.
We concluded that epidural analgesia, very often used to control postoperative or chronic pain, although very effective is not free from severe, although rare complications, such as epidural abscess.
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Submitted for publication March 26, 2003
Accepted for publication June 12, 2003
* Received from Centro de Ensino e Treinamento em Anestesiologia do Instituto Penido Burnier e Centro Médico de Campinas, SP