Print version ISSN 0034-7094
Rev. Bras. Anestesiol. vol.56 no.2 Campinas Mar/Apr. 2006
Epidural hematoma after general anesthesia associated with postoperative analgesia with epidural catheter in patient using low molecular weight heparin. Case report*
Ocurrencia de hematoma postanestesia general asociada a analgesia postoperatoria con cateter peridural en paciente que usa heparina de bajo peso molecular. Relato de caso
Ranger Cavalcante da Silva, TSA, M.D.I; André Morais e Silva, M.D.II; Fernando Santos Laffitte, M.D.III; Gilbert Jamus, M.D.IV
em Medicina e Cirurgia pela Universidade Federal do Paraná; Co-Responsável
pelo CET do HC-UFPr; Anestesiologista do Hospital Vita de Curitiba e Vita Batel
IIAnestesiologista do Hospital Vita Curitiba e Vita Batel
IIIOrtopedista Cirurgião de Coluna Hospital Vita Curitiba
IVClínico e Cirurgião de Coluna Hospital Vita Curitiba
AND OBJECTIVES: Presents a patient case with epidural hematoma, in the course
of the use of epidural catheter and low molecular weight heparin, her clinical
condition and treatment.
CASE REPORT: A 75-year old female patient, submitted to the fixation of lumbar spine by anterior route, who, in the postoperative period, developed a clinical condition of progressive paralysis of the lower limbs, with loss of sensitivity and presenting no intense radicular pain. The treatment was the immediate medullar decompression, with drainage and surgical cleaning of a epidural hematoma, which extended from the 5th to the 10th thoracic vertebrae. After the drainage of the hematoma, the patient gradually recovered the strength in the lower limbs, was discharged in ten days with a condition of sphincterian dysfunction. After three months, the condition receded and there was no definitive neurological sequel.
CONCLUSIONS: The quick diagnosis with early surgical intervention is the most effective treatment for the reduction of neurological damage, in patients that develop postoperative epidural hematoma. The use of low molecular weight heparin, in the course of the use of epidural catheter, requires the strict compliance with the established protocols so that the risks of epidural hematoma development can be reduced.
Key words: ANESTHETIC TECHNIQUES, Regional: continuous epidural; COMPLICATIONS: epidural hematoma; DRUGS: fractioned heparin.
Y OBJETIVOS: presentar el caso de una paciente con hematoma peridural, con
uso actual de catéter peridural y heparina de bajo peso molecular, su cuadro
clínico y tratamiento.
RELATO DEL CASO: Paciente de 75 años, sometida a la fijación de columna lumbar por vía anterior, que desarrolló en el postoperatorio un cuadro clínico de parálisis progresiva en los miembros inferiores, con pérdida de la sensibilidad, sin presentar dolor radicular intenso. El tratamiento fue descompresión medular inmediata, con drenaje y limpieza quirúrgica de un hematoma peridural, que se extendía desde la quinta hasta la décima vértebra toráxica. Después del drenaje del hematoma la paciente recuperó gradualmente la fuerza en los miembros inferiores, recibió alta en diez días con cuadro de disfunción de esfínteres. Después de tres meses el cuadro remitió y no hubo secuela neurológica definitiva.
CONCLUSIONES: El rápido diagnóstico con intervención quirúrgica precoz es el tratamiento más eficaz para la reducción de la lesión neurológica, en pacientes que desarrollan hematoma peridural postoperatorio. La utilización de heparina de bajo peso molecular, con uso actual de catéter peridural, exige la adhesión estricta a protocolos establecidos, para que se reduzcan los riesgos del desarrollo de hematoma peridural.
After the introduction of low molecular weight heparin or (LMWH) in clinical practice, there was an increase in the incidence of epidural hematoma in surgical patients submitted to regional anesthesia 1. The objective of this report was to present a clinical case of epidural hematoma, after surgery of lumbar spine, in patient using LMWH.
Female patient, 75 years old, 40 kg, submitted to surgery for decompression and lumbar fixation by the anterior-lateral retroperitoneal route, under general anesthesia and with epidural catheter for postoperative analgesia. She presented, during the pre-anesthetic evaluation, systemic hypertension. She was taking treated with 50 mg of hydrochlorothiazide per day. Piroxicam, fluoxetine, chloroquine for the control of generalized osteo-articular pain. She further used the phytotherapic drug ginkobiloba, discontinued one week before the surgery. The preoperative laboratorial exams were normal with a coagulagram presenting a activated partial thromboplastin time (APTT) of 26 seconds, prothrombin time (PT) of 12 seconds, platelet count of 157,000 mm3 and bleeding time (BT) of five minutes.
After monitoring with noninvasive arterial blood, cardioscope, pulse oximeter, venoclysis in the upper left limb was performed with an 18G catheter. Subsequently, the patient was positioned in a left lateral decubitus and the epidural space was acessed in T10-T11 level, with an 18G needle. A 20G epidural catheter was introduced 3 cm beyond the needle point. The puncture was single, with no aspiration of blood through the needle. During the surgery, a solution containing 40 mg of 0,5% ropivacaine and 1 mg of morphine was administered through the catheter. The duration of surgery was four hours and no adverse effects occurred, such as bleeding or hemodynamic instability. During the surgery, the patient was received 2,500 mL of saline. After the patient emerged from anesthesia, she was referred to the recovery room (RR). At the RR, the patient was able to move her lower extremities and did not complain of any pain. After one hour and 30 minutes, she was sent to the ward. During the postoperative period, she was given one single daily dose of enoxaparin (40 mg), thromboembolic events prophylaxis. The first dose of enoxaparin was administered eight hours after the epidural puncture. Around 12 hours after the procedure, the anesthesiologist on duty repeated the epidural morphine without local anesthetics and there was no report of any symptom, nor was it observed any neurological deficit. During the dawn of the first postoperative day, the patient presented progressive difficulty in moving her feet, then her legs, and finally loss of sensitivity in the lower extremities. She was immediately referred to perform a magnetic nuclear resonance of the thoracic lumbar spine, which identified an extensive epidural hematoma (T5-T10) compressing the medulla. She was submitted to decompressive surgery with wide laminectomy of T5 to T10, removal of the clot formed, clean and drain (Figures 1 and 2). It was not possible to identify the exact location of the bleeding. The interval between the beginning of the symptoms and the beginning of the decompressive surgery was of six hours. During the surgical procedure, the patient was kept hemodynamically stable, she received two units of packed red cells, since her initial hemoglobin was of 9 g/dL. The total time of the surgery was two hours and fifteen minutes. When she recove-red from anesthesia, she already presented a partial recovery of the movements in the lower extremities, with impaired sensitivity. She evolved with progressive neurological improvement and was discharged after ten days, with fecal and urinary incontinence, which receded completely in three months.
The epidural route is excellent for the administration of analgesics, because it does not require sophisticated equipment, its cost is lower, it is safe, it reduces the risk of thromboembolism, it reduces bleeding and the risk of blood transfusions1-7. However, the use of continuous epidural, during the effect of LMWH, requires the strict compliance with established protocols in order to reduce the risks of epidural hematoma. Other important aspects, in the patients who use LMWH, are the frequent neurological evaluation after surgery so as to identify neurological deficits, the solution type used for analgesia so as not to interfere with the neurological evaluation and the appropriate moment to remove the catheter, which can be as traumatic as the epidural puncture 1. The present accurate incidence of neurological deficit resulting from hemorrhagic complications is unknown. The incidence quoted in the literature is estimated in less than 1:150.000 for epidural anesthesia and less than 1:220.000 for subarachnoideal anesthesia 8. In patients with epidural catheter using LMW, the incidence observed may reach 1 to 3,000, as compared with 1 to 40,000 in subarachnoideal anesthesia. The estimate is based on the sales of LMW, prevalence of subarachnoideal anesthesia and cases reported in the United States 9. It is possible to identify a few risk factors for the development of epidural hematoma and not being able to stratify the risk or the interaction between risk factors 8 (Chart I).
Vandermeulen et al. 11 after revision of the literature between 1906 and 1994, reported 61 cases of epidural hematoma, associated with epidural or subarachnoideal anesthesia. In 68% of the cases (42 patients) there was an association with coagulation disturbances. Around 25 patients received heparin, intravenously or subcutaneously. In 5 patients, the use of heparin was presumed because they were patients that had undergone vascular surgeries. In 12 patients there was evidence of coagulopathy or thrombocytopenia or treatment with oral anticoagulants, antiplatelets (aspirin, indometacin, ticlopidine), thrombolytic (urokinase) or dextran 70 before or after epidural or spinal anesthesia. Difficulty of puncture or introduction of catheter was found in 15 patients. In 57 patients (87%), there were a coagulation disturbance or difficulties in puncturing and introducing the catheter. The neurological evolution was informed in 55 of the 61 patients who presented epidural hematoma. The neurological result was considered good or partial in 38% of the patients (10/26), when the surgical intervention took place up to 8 hours after the beginning of the symptoms (Table I)19. It is evident that the best results are obtained from a quick diagnostic and from an early surgical intervention.
With the increasing use of LMWH it was observed an increase in the number of notifications in the United States between 1993, year when the LMWH was introduced, and 1998, with more than 40 cases notified to the manufacturer. An American task force, in 1998 developed a protocol, which was updated in 2003, for the use of LMWH and anesthesia in the neuraxial (Table II) 8.
After 1998, there were 13 cases of epidural hematoma associated with regional anesthesia in the United States. In addition to LMWH, five patients received ketorolac, one received ibuprophen and one received non fractioned heparin intravenously, for a vascular procedure 11.
The enoxaparin presents distinct pharmacological characteristics when compared with the non fractioned heparin (Table III). It is not necessary to monitor the anticoagulant response (Anti Xa), its action is not reverted by protamine, its half-life is longer, its protein binding is smaller, conferring more stability in its bioavailability 8,13. The LMWH may have its effects prolonged in patients with renal insufficiency 8,13. The prolonged use of LMWH may lead to an accumulation of anti Xa activity and fibrinolysis 8,13. The monitoring of the levels of anti Xa activity is not recommended because it is not an index for estimate the bleeding risk and because it does not help in handling the patients who received regional anesthesia 8.
In general, there are two protocols that are most frequented quoted in the literature relative to the prophylaxis of the thromboembolic phenomena. One is European and the other is American. Europe has a long tradition in the use of LMWH, with few hemorrhagic complications 14,15. The European protocol starts LMWH 12 hours before the procedure, using a single daily dose of 40 mg 17. The initial American protocol introduced LMWH two to six hours after surgery and used two daily doses of 30 mg 8,16. After one year and two hematomas, the posological regimen recommended was changed and the first dose started to be administered 12 to 24 hours after the surgical procedure 8. Recent American studies have shown the efficacy of the single daily posological regimen with dalteparin, started during the postoperative period, nearing the European regimen 18. The updated guidelines of the American Society of Regional Anesthesia (ASRA) suggest the removal of the epidural catheter from two to four hours before the beginning of the posological regimen that uses two daily doses of enoxaparin (60 mg/day). This way, the maintenance of the epidural catheter is not recommended in patients receiving two daily doses of LMWH. When the epidural puncture is traumatic, with the presence of blood in the syringe, the first dose of LMWH should be postponed for 24 hours.
The most frequent neurological changes in patients with epidural hematoma are the loss of strength in the lower limbs, followed by loss of sensitivity, lumbar pain and vesical dysfunction. Intense radicular pain is rarely observed 8. Quite often, the initial diagnostic is delayed because the picture is thought to be a residual anesthesia effect 10. The final treatment and that with the best neurological results is the surgical evacuation of the hematoma, as long as it is performed up to 8 hours after the beginning of the symptoms 11. There are several protocols for the prophylaxis of deep vein thrombosis in patients with high risk for the development of this complication. However, whenever a protocol is established, we must adjust it individually. Patients at an advanced age, very low weight, hepatic or renal diseases, may present altered pharmacokinetic and pharmacodynamic responses. In addition, one must also take into consideration other pharmaceutical substances that might interfere with the coagulation or even the phytotherapic drugs that have action on the hemostasy (Table IV). Up to the present time, there is no indication for the interruption of the phytotherapic drugs before surgical procedures, to allow the extinction of their effects on hemostasy 8. Similarly, there are not sufficient studies confirming the safety of the association of phytotherapic drugs and LMWH in patients that received regional anesthesia 8.
The patient was treated with decompressive surgery because the symptoms started less than 8 hours before and the neurological picture presented progressive worsening. The surgical approach proved to be appropriate, with a rapid improvement of the motor strength and the sensitivity in the immediate period after surgery. The absence of definitive sequels can be attributed to a fast diagnostic and surgical intervention. The case alerts to the need of following rigid protocols when one uses regional anesthesia, particularly the continuous one, and LMWH. The frequent neurological evaluation during the maintenance of the catheter, as well as after it is removed, is fundamental. When one uses local anesthetic during analgesia, this must be done with solutions that do not interfere with the evaluation of the motor strength, since one of the early signs of the development of a epidural hematoma is the loss of motor strength in the lower limbs. The fixation of the epidural catheter, although this is quite frequently considered secondary, is fundamental so that there is no accidental dislocation of the catheter during the peak of anticoagulant action.
The surgical interventions for decompression and lumbar fixation, performed by a few surgical teams at our hospital, are performed with general anesthesia associated with continuous epidural anesthesia, for postoperatory analgesia. All the patients submitted to decompression and lumbar fixation, by this surgical team, receive enoxaparin during the postoperative, 40 mg once a day, started from 8 to 12 hours after the procedure. This was the only case, up to the present time, of epidural hematoma associated with regional anesthesia and LMWH.
New medications are being introduced for the prophylaxis of deep vein thrombosis as the thrombolytic antagonist (Ximelagatrana Exantaâ), which will require, from the anesthesiologists, further studies of the cost/benefit relation of the referred to pharmaceutical drugs, as well as the adequacy of guidelines for their use in patients who received regional anesthesia. The regional anesthesia is safe in patients who use prophylaxis for deep vein thrombosis with LMWH, as long as the protocols for their use are followed and that neurological monitoring of the patient is performed regularly, even after the removal of the epidural catheter.
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Dr. Ranger Cavalcante da Silva
R. Ângelo Sampaio 1166/401
80250-120 Curitiba, PR
for publication 05 de julho de 2005
Accepted for publication 20 de dezembro de 2005
* Received from Hospital de Clínicas da Universidade Federal do Paraná (HC-UFPr), Curitiba, PR