Hemiparesis post open radical nephrectomy – Nightmare for surgeon

INTRODUCTION

Hemiparesis or unilateral muscle weakness is a very rare occurrence post-nephrectomy. It occurs rarely when analgesia is managed by epidural analgesia. Unilateral sensory or motor weakness is a rare occurrence of epidural analgesia which is a result of epidural catheter position, lateral displacement of epidural catheter, or unequal distribution of anesthetic drug.

CASE REPORT

We report a case of left-sided hemiparesis post open radical nephrectomy whose peri procedure analgesics were managed by epidural catheter.

This is a case of a 49-year-old male who was hypertensive with no other co-morbidity and diagnosed to have a large complex cystic lesion – Bosniak type 4 and posted electively for left radical nephrectomy under general endotracheal tube anesthesia. The patient was evaluated in pre-anesthetic checkup and optimized as per the anesthesiologist’s advice. On the day of surgery, the patient was again evaluated by anesthesia consultant and urologist posted for the case. Pre-operative vitals of the patient were stable and the patient was taken to the operating room. The anesthesiologist planned for general endotracheal tube intubation with epidural analgesia for this case. The anesthesiologist secured the epidural catheter at L1-L2 space after testing and securing epidural catheter, and general endotracheal tube anesthesia was given by anesthetists as per the protocol. Surgery was done by an experienced urologist. The patient was taken in the supine position and left open radical nephrectomy with colo-colic anastomosis was done by transperitoneal approach and subcostal incision. Total duration of surgery was approximately 2½ h with acceptable minimal blood loss. Colo-colic anastomosis was done as the tumor was badly adherent to the descending colon. Total surgery was uneventful. The patient was extubated by an anesthetist after giving reversal and the patient was fully awake with stable vitals. The Glasgow Coma Scale was 15/15, pain score was 2–3/10 by Visual Analog Scale (VAS), and the patient was moving all four limbs and following commands with spontaneous eye opening. The patient was shifted to the surgical intensive care unit for postoperative care and monitoring. The modified aldrete scale score was 10/10. The anesthetist started epidural ropivacaine 0.2% for post-operative analgesia at the rate of 5 mL/h. The patient was uneventful postoperatively until he started complaining of generalized weakness of the left side almost after 5 h postoperatively. Immediately, clinical evaluation was done and vitals were stable. All needful laboratory investigations were sent and a neurophysician was involved as the patient had a progressive increase in weakness by the next hour for presenting a complaint. Laboratory investigations were within normal limits including electrolytes. The neuro physician suggested magnetic resonance imaging (MRI) brain as the patient developed left hemiparesis and was suspected of Cerebrovascular accident (CVA) with motor weakness (power of UL 2/5 and LL 2/5) and the patient was planned for MRI brain. Anesthesiologist was consulted and they suggested stopping the epidural infusion of 0.2% ropivacaine. The patient started regaining motor and sensory power dramatically after stopping the epidural infusion and the patient completely recovered motor power of UL 5/5 and LL 5/5 1½ h after complete stoppage of the epidural infusion of 0.2% ropivacaine and started complaining of pain at surgical site with VAS 7/10. After discussion with the anesthetist, alternative analgesic IV tramadol 100 mg and IV paracetamol 1g were given. The VAS became 2/10.

DISCUSSION

Epidural analgesia is the most common analgesia used for management of post-operative pain in the major thoracoabdominal surgeries. The analgesia is delivered either by use of single needle or epidural catheter. Epidural catheter delivers the anesthetic drug as a constant infusion into the epidural space.

Hong et al.^[1] conducted a study that concluded that there are various factors responsible for the spread of local anesthetic agent into the epidural space. It was found that the contrast medium spreads in cranial direction with more extensive distribution than in the caudal direction.^[1] It was also noted that total mass of local anesthetic appears most important factor in determining the extent of sensory, sympathetic, and motor neural blockade whereas the site of epidural needle/catheter placement governs the pattern of distribution of blockade relative to the injection site.^[2]

Visser et al.^[2] conducted the study in which it was found that the major factor that limits the usefulness of epidural drug administration is uneven drug effect. The cause of unilateral blockade can be attributed to uneven distribution of injected solution due to placement of tip of epidural catheter at sites other than posterior midline or due to the presence of air bubbles and epidural fibrous barrier.^[3]

In the study conducted by Tassone et al., concluded in their case report that the extensive unilateral sensory and motor blockade is probably due to the presence of midline posterior and/or anterior septum with adequate post-operative analgesia presumably from eventual spread of the local anesthetic to the Dural cuffs (root sleeves) and subsequent entry into the cerebral spinal fluid by way of arachnoid granulations.^[4] Premature catheter dislodgment is another factor responsible for the post-operative unilateral blockade and/or lower-limb weakness which results in premature discontinuation of post-operative epidural infusion.^[5]

A study conducted by Ahmed and Baig found that lower-limb motor weakness was more common with the placement of lumbar epidural catheter than that of lower thoracic levels. It was also concluded that discontinuation of the epidural infusion, using the lower concentrations of anesthetic drug resulted in the reversal of lower-limb motor blockade.^[6]

In our case, the anesthesiologist secured epidural catheter in L1–L2 space. It was fixed almost 5 cm inside the epidural space and 10 cm at skin level. Our patient developed unilateral weakness on the left side because of the probability of placing the epidural catheter tip more on the left side, there may be epidural fibrous tissue, air bubbles when giving the epidural drugs, uneven distribution of epidural fat, or nonuniform epidural space. Epidurogram can be used to confirm the correct position of epidural catheter tip and drug.

CONCLUSION

This case illustrates a rare extensive unilateral epidural spread of local anesthetic in the epidural space resulting in hemiparesis. Epidurogram can be used to confirm the correct position of epidural catheter tip and local anesthetic spread.