The use of epidural suction catheters to prevent postoperative hematoma formation is common in neurosurgical practice. Significant cardiovascular changes secondary to intracranial hypotension have been reported after application of negative pressure drainage systems, although these reports are more frequently associated with intracranial surgery.1 We describe a case of sudden arterial hypotension most likely caused by application of high negative pressure suction to a thoracic epidural drain. Written informed consent was obtained for the writing of this case report.
A 68-year-old, 76-kg male with known metastatic mixed small and large cell lung carcinoma presented with mild changes in gait and hyperreflexia of the lower limbs. His magnetic resonance imaging demonstrated spinal cord compression from a vertebral body and left pedicular metastasis at the level of T8. He was scheduled to undergo multilevel T6–T10 screw fixation, partial vertebrectomy, and excision of a compressive metastatic spinal tumor via T8 transpedicular approach.
His preoperative laboratory measurements were normal with the exception of a mildly increased blood urea nitrogen. His electrocardiogram showed sinus rhythm and a heat rate of 65 bpm with incomplete right bundle branch block.
Monitoring included a 5-lead electrocardiogram, pulse oximetry, and an intraarterial catheter. His baseline heart rate and arterial blood pressure were 85 bpm and 150/80 mm Hg, respectively. Induction of anesthesia was commenced with remifentanil 0.2 mcg/kg/min and propofol 200 mg. Muscle relaxation was facilitated with rocuronium 50 mg, and the patient’s trachea was intubated with a 8.0 reinforced endotracheal tube. Maintenance of anesthesia consisted of desflurane and remifentanil along with a ketamine infusion of 8 mg/h as part of the perioperative analgesic management plan. An infusion of metaraminol was given throughout to maintain a mean arterial blood pressure higher than 70 mm Hg. Dexamethasone 8 mg and cefazolin 2 g were administered postinduction.
With the patient positioned prone, pedicle screws were placed in the T6, T7, T9, and T10 pedicles bilaterally connected to longitudinal rods to achieve stabilization, and a left T8 hemilaminectomy was performed. The tumor that was clearly compressing nerves at that point was removed, and the T8 nerve root avulsed during this removal. Further tumor was resected from anterior to the spinal cord. At the point where the nerve root was avulsed, a Weck hemostat clip was placed over the dural defect and valsalva used to confirm absence of cerebrospinal fluid (CSF) leak. A deep wound drain (Jackson Pratt™, Cardinal Health, USA) was placed in situ overlying the dura to prevent epidural cord compression from any hematoma that may develop due to hemorrhage from the raw surface of subperiosteal dissected muscle. The wound was then closed.
At this point, we noticed a sudden and significant decrease in his systolic blood pressure from 100 to 55 mm Hg while his heart rate remained unchanged at 60 bpm. The patient had been consistently hemodynamically stable for the previous 5 hours and had hemoglobin of 95 g/L just before the event. Furthermore, no alterations had been made to any drug infusions or anesthetic drugs.
Initial thoughts of hypotension secondary to hemorrhage resulted in immediate administration of boluses of fluid and metaraminol. However, there was no change to the patient’s blood pressure. The surgeon was immediately alerted and subsequently clamped off the negative suction drainage. The suction drain was immediately removed, and his blood pressure returned to normal within seconds. Approximately 100 mL of blood-stained serous fluid was noted in the suction drainage. The wound was reopened, and a small hematoma was noted around the cord. The dura appeared to be flattened, empty, and devoid of CSF. The dura was repaired and the wound was reclosed.
After tracheal extubation, the patient was transferred to the postanesthetic care unit where he made an uneventful recovery. He had no neurological sequelae. A postoperative computed tomography scan of the patient’s brain revealed subjectively reduced size of the lateral ventricles in comparison with a previous preoperative staging brain computed tomography.
We describe severe hypotension in a patient after application of negative pressure suction drainage to a thoracic epidural drain. Cardiovascular collapse after a sudden decrease in intracranial pressure has been described.1 However, in the majority of these reports, it occurred during ventricular drainage after craniotomy.
We postulate that the high negative pressure suction drainage applied to a thoracic epidural drain resulted in a significant volume of CSF being rapidly drained leading to a sudden decrease in intracranial pressure. There have been reports that rapid removal of CSF in patients with application of negative pressure may result in a sudden state of intracranial hypotension. This could lead to rostral movement of the brain or brainstem nuclei responsible for changes in cardiac rhythm or arterial hypotension or both.1 Hernández-Palazón et al.1 described a significant decrease in heart rate without a significant decrease in blood pressure immediately after connecting the vacuum system, while Jacka and Wood2 describe a case of bradycardia and cardiac arrest during application of negative suction drainage to a lumbar intrathecal catheter before craniotomy. Van Roost et al.3 reported 2 cases of arterial hypotension and severe bradycardia after application of a subgaleal suction drain. In addition, the same authors hypothesized that brain changes termed as “pseudohypoxic brain swelling” occurred in those patients in whom negative pressure drainage systems were applied. Karamchandani et al.4 postulated a separate mechanism of hypotension and bradycardia secondary to a subgaleal drain. They proposed that traction on the scalp nerve endings when hanging the drain might have triggered the trigemino-cardiac reflex.4
The use of spinal epidural drains has been associated with a wide variety of complications, which become more pertinent in the presence of an incidental durotomy putting the patient at risk of complications of CSF overdrainage. Complications of CSF drainage are reported both in the context of closed suction epidural drainage systems and also in relation to CSF lumbar drainage catheters which are commonly used either to treat external CSF leakage5–7 or improve spinal cord perfusion in the context of thoracic aortic surgery,7 both of which have demonstrated efficacy.
Anesthesiologists should be aware of potential complications resulting from neurosurgical drainage systems, and care should be taken during closure of dura and application of drainage systems. If drains are used, negative pressure should be applied gradually and the contents should be closely observed for excessive CSF drainage. If cardiovascular changes do occur, closure of the drainage system as well as appropriate pharmacologic treatment should be considered.
1. Hernández-Palazón J, Tortosa JA, Sánchez-Bautista S, Martínez-Lage JF, Pérez-Flores D. Cardiovascular disturbances caused by extradural negative pressure drainage systems after intracranial surgery. Br J Anaesth. 1998;80:599–601
2. Jacka M, Wood G. Bradycardia related to sudden decreases in intracranial pressure during craniotomy. Anesth Analg. 1994;78:1022–3
3. Van Roost D, Thees C, Brenke C, Oppel F, Winkler PA, Schramm J. Pseudohypoxic brain swelling: a newly defined complication after uneventful brain surgery, probably related to suction drainage. Neurosurgery. 2003;53:1315–26
4. Karamchandani K, Chouhan RS, Bithal PK, Dash HH. Severe bradycardia and hypotension after connecting negative pressure to the subgaleal drain during craniotomy closure. Br J Anaesth. 2006;96:608–10
5. Açikbaş SC, Akyüz M, Kazan S, Tuncer R. Complications of closed continuous lumbar drainage of cerebrospinal fluid. Acta Neurochir (Wien). 2002;144:475–80
6. Huang CI, Huang MC, Chen IH, Lee LS. Diverse applications of continuous lumbar drainage of cerebrospinal fluid in neurosurgical patients. Ann Acad Med Singapore. 1993;22:456–8
7. Fedorow CA, Moon MC, Mutch WA, Grocott HP. Lumbar cerebrospinal fluid drainage for thoracoabdominal aortic surgery: rationale and practical considerations for management. Anesth Analg. 2010;111:46–58