Reversible Paralysis and Loss of Deep Pain Sensation After Topical Intrathecal Morphine Administration Following Durotomy Yael Chamisha, DVM, Merav H. Shamir, DVM, Diplomate ECVN, Yael Merbl, DVM, and Orit Chai, DVM, Diplomate ECVN Department of Neurology and Neurosurgery, The Veterinary Teaching Hospital, Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel
Corresponding Author Yael Chamisha, DVM, Department of Neurology and Neurosurgery, The Veterinary Teaching Hospital, Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel. E‐mail: [email protected] Submitted August 2013 Accepted February 2014 DOI:10.1111/j.1532-950X.2014.12192.x
Objective: To report 2 dogs that developed temporary pelvic limb paralysis with loss of deep pain sensation after topical intrathecal morphine administration during spinal surgery. Study Design: Clinical report. Animals: Dogs (n ¼ 2). Methods: A 5‐year‐old castrated male French Bulldog with a subarachnoid diverticulum at T9–T10 and a 9.5‐year‐old castrated male Belgian Shepherd dog with a herniated disc at T12–T13 and intradural component, had Gelfoam soaked with morphine placed over the dura mater defect. Results: Pelvic limb paralysis and loss of deep pain sensation was noticed immediately after recovery from anesthesia. After intravenous naloxone administration, both dogs immediately regained ambulation and normal pain sensation; however the effect was temporary lasting only a few hours. Permanent resolution of clinical signs occurred 24 hours after surgery. Conclusions: Topical intrathecal morphine administration resulted in temporary pelvic limb paralysis and loss of deep pain sensation. This route of administration should be used cautiously until further determination of the efficacy and adverse effects associated with topical intrathecal morphine administration.
After vertebral laminectomy, dogs experience postoperative pain, which might lead to complications such as prolonged recovery and increased morbidity1–3 so, appropriate perioperative analgesia is recommended.4 Morphine is commonly administered for perioperative pain management in dogs having spinal surgery, either by multiple intravenous, intramuscular or oral doses or as a constant rate infusion.1,3–5 Because of the presence of opioid receptors in the dorsal gray column of the spinal cord, morphine can be locally administered ensuring segmental analgesia, reducing potential adverse effects associated with systemic administration.3,6,7 Morphine can be delivered directly to the spinal cord by epidural, direct extradural, intrathecal, and combined epidural and intrathecal administration.1,4,5,8–11 Topical extradural morphine administration at the laminectomy site in dogs undergoing thoracolumbar spinal surgery1,5 prolongs postoperative analgesia and limits the need for systemic analgesia, without adverse effects. In people, injection of analgesic drugs into the cerebrospinal fluid (CSF) provides faster onset of, and recovery from, spinal block and better control of postoperative pain, when compared to epidural anesthesia.3,9,12 Although relatively safe, intrathecal morphine administration in people and dogs has
been associated with adverse effects such as pruritus, nausea and vomiting, urinary retention, and respiratory depression.7,13–16 In dogs, intrathecal analgesia is considered effective despite the limited number of reported studies.13,17 Our purpose is to report 2 dogs that developed temporal pelvic limb paralysis with loss of deep pain sensation after topical direct intrathecal morphine administration during spinal surgery. Both dogs had a durotomy and Gelfoam soaked with morphine was placed over the dura mater defect, resulting in local penetration of the morphine into the subarachnoid space.
CLINICAL REPORT Dog 1 A 5‐year‐old castrated male French Bulldog was presented with pelvic limb weakness, and fecal and urinary incontinence that had progressed over 1 month. Physical examination was unremarkable, but neurologic evaluation revealed ambulatory paraparesis. Proprioceptive deficits were present in both pelvic limbs, and segmental spinal reflexes were intact. Neuroanatomic localization was at T3–L3 spinal cord segments.
Veterinary Surgery 9999 (2014) 1–5 © Copyright 2014 by The American College of Veterinary Surgeons
1
Reversible Paralysis and Absent Deep Pain After Spinal Morphine Administration
Thoracolumbar survey radiographs and CSF analysis were normal. Lumbar myelography demonstrated focal dorsal accumulation of the contrast medium in the subarachnoid space, with a “tear‐drop” shaped enlargement on the lateral projection at T9–T10 leading to a diagnosis of spinal subarachnoid diverticulum (SAD). The dog was premedicated with acepromazine (0.025 mg/ kg intramuscularly [IM]) and morphine (0.35 mg/kg IM), induced with propofol (1 mg/kg intravenously [IV]) and diazepam (0.5 mg/kg IV) and maintained with isoflurane in 100% oxygen delivered through a non‐rebreathing circuit. Dorsal laminectomy followed by durotomy and marsupialization of the dural diverticulum to the surrounding paraspinal fascia were performed. After decompression, Gelfoam soaked with preservative‐free morphine (0.5 mg/kg; Morphine Sulfate, Silodosin, 5 mg/5 mL, RAFA Laboratories, Ltd., Jerusalem, Israel) was placed over the dural defect and the surgical site closed. No complications occurred during surgery. On neurologic evaluation 3 hours after recovery from anesthesia, the dog had complete paraplegia with no deep pain sensation and intact segmental spinal reflexes. A complication attributed to the intrathecal morphine administration was suspected. Naloxone (0.02 mg/kg IV) was administrated and the dog regained ambulation and normal pain sensation immediately. However, the effect was temporary as the dog had recurrent neurologic deterioration on re‐evaluation
Corresponding Author Yael Chamisha, DVM, Department of Neurology and Neurosurgery, The Veterinary Teaching Hospital, Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel. E‐mail: [email protected] Submitted August 2013 Accepted February 2014 DOI:10.1111/j.1532-950X.2014.12192.x
Objective: To report 2 dogs that developed temporary pelvic limb paralysis with loss of deep pain sensation after topical intrathecal morphine administration during spinal surgery. Study Design: Clinical report. Animals: Dogs (n ¼ 2). Methods: A 5‐year‐old castrated male French Bulldog with a subarachnoid diverticulum at T9–T10 and a 9.5‐year‐old castrated male Belgian Shepherd dog with a herniated disc at T12–T13 and intradural component, had Gelfoam soaked with morphine placed over the dura mater defect. Results: Pelvic limb paralysis and loss of deep pain sensation was noticed immediately after recovery from anesthesia. After intravenous naloxone administration, both dogs immediately regained ambulation and normal pain sensation; however the effect was temporary lasting only a few hours. Permanent resolution of clinical signs occurred 24 hours after surgery. Conclusions: Topical intrathecal morphine administration resulted in temporary pelvic limb paralysis and loss of deep pain sensation. This route of administration should be used cautiously until further determination of the efficacy and adverse effects associated with topical intrathecal morphine administration.
After vertebral laminectomy, dogs experience postoperative pain, which might lead to complications such as prolonged recovery and increased morbidity1–3 so, appropriate perioperative analgesia is recommended.4 Morphine is commonly administered for perioperative pain management in dogs having spinal surgery, either by multiple intravenous, intramuscular or oral doses or as a constant rate infusion.1,3–5 Because of the presence of opioid receptors in the dorsal gray column of the spinal cord, morphine can be locally administered ensuring segmental analgesia, reducing potential adverse effects associated with systemic administration.3,6,7 Morphine can be delivered directly to the spinal cord by epidural, direct extradural, intrathecal, and combined epidural and intrathecal administration.1,4,5,8–11 Topical extradural morphine administration at the laminectomy site in dogs undergoing thoracolumbar spinal surgery1,5 prolongs postoperative analgesia and limits the need for systemic analgesia, without adverse effects. In people, injection of analgesic drugs into the cerebrospinal fluid (CSF) provides faster onset of, and recovery from, spinal block and better control of postoperative pain, when compared to epidural anesthesia.3,9,12 Although relatively safe, intrathecal morphine administration in people and dogs has
been associated with adverse effects such as pruritus, nausea and vomiting, urinary retention, and respiratory depression.7,13–16 In dogs, intrathecal analgesia is considered effective despite the limited number of reported studies.13,17 Our purpose is to report 2 dogs that developed temporal pelvic limb paralysis with loss of deep pain sensation after topical direct intrathecal morphine administration during spinal surgery. Both dogs had a durotomy and Gelfoam soaked with morphine was placed over the dura mater defect, resulting in local penetration of the morphine into the subarachnoid space.
CLINICAL REPORT Dog 1 A 5‐year‐old castrated male French Bulldog was presented with pelvic limb weakness, and fecal and urinary incontinence that had progressed over 1 month. Physical examination was unremarkable, but neurologic evaluation revealed ambulatory paraparesis. Proprioceptive deficits were present in both pelvic limbs, and segmental spinal reflexes were intact. Neuroanatomic localization was at T3–L3 spinal cord segments.
Veterinary Surgery 9999 (2014) 1–5 © Copyright 2014 by The American College of Veterinary Surgeons
1
Reversible Paralysis and Absent Deep Pain After Spinal Morphine Administration
Thoracolumbar survey radiographs and CSF analysis were normal. Lumbar myelography demonstrated focal dorsal accumulation of the contrast medium in the subarachnoid space, with a “tear‐drop” shaped enlargement on the lateral projection at T9–T10 leading to a diagnosis of spinal subarachnoid diverticulum (SAD). The dog was premedicated with acepromazine (0.025 mg/ kg intramuscularly [IM]) and morphine (0.35 mg/kg IM), induced with propofol (1 mg/kg intravenously [IV]) and diazepam (0.5 mg/kg IV) and maintained with isoflurane in 100% oxygen delivered through a non‐rebreathing circuit. Dorsal laminectomy followed by durotomy and marsupialization of the dural diverticulum to the surrounding paraspinal fascia were performed. After decompression, Gelfoam soaked with preservative‐free morphine (0.5 mg/kg; Morphine Sulfate, Silodosin, 5 mg/5 mL, RAFA Laboratories, Ltd., Jerusalem, Israel) was placed over the dural defect and the surgical site closed. No complications occurred during surgery. On neurologic evaluation 3 hours after recovery from anesthesia, the dog had complete paraplegia with no deep pain sensation and intact segmental spinal reflexes. A complication attributed to the intrathecal morphine administration was suspected. Naloxone (0.02 mg/kg IV) was administrated and the dog regained ambulation and normal pain sensation immediately. However, the effect was temporary as the dog had recurrent neurologic deterioration on re‐evaluation
