50th Annual Regional Anesthesiology and Acute Pain Medicine Meeting

Spinal Anesthesia for Total Hip Arthroplasty in an Achondroplastic Patient

Introduction

Achondroplasia is a disorder that results in skeletal dysplasia, including atlantoaxial instability, kyphoscoliosis, spinal stenosis
General anesthesia poses the risk of a potential difficult airway, whereas neuraxial presents challenges of procedure difficulty, unpredictable spread, and higher incidence of neurologic injury
Anesthetic plans for this population have reported general anesthesia as the historical preference over neuraxial, particularly for cesarean sections

Case Presentation

56 year-old female with history of achondroplasia, kyphoscoliosis, multilevel spinal stenosis status post C3 through C5 fusion, and hip dysplasia presented for left total hip arthroplasty
Inter-incisor distance > 4 cm, thyromental distance > 6 cm, Class I Mallampati score, and limited neck extension. Previous intubation was a Grade I view with a C-MAC video laryngoscope D-blade
After discussing risks and benefits of general and neuraxial anesthesia, the patient opted to proceed with a combined spinal-epidural

Perioperative Course

Patient was positioned upright with NIBP, pulse oximetry, supplemental oxygen, and a timeout was completed
Procedure was performed under sterile technique with a 3.5 inch 17 gauge Tuohy needle and 5 inch 25 gauge Gertie Marx spinal needle
First attempt at L3-4 with midline approach was unsuccessful with subsequent decision to attempt at a new level
Loss of resistance obtained at L4-5, spinal needle inserted with return of cerebral spinal fluid, followed by barbotage with off-label intrathecal use of 60 mg of 2% mepivacaine. Placement of a 21 gauge epidural catheter was unsuccessful and the decision was made to proceed to the operating room
Surgical block confirmed prior to incision. Patient was sedated and maintained spontaneous ventilation for a total operative time of 150 minutes. Approximately 90 minutes after spinal was administered, sedation was supplemented with fentanyl and increasing doses of propofol

Discussion

No established intrathecal dose of local anesthetic for patients with achondroplasia. Reported spinal dosing for cesarean section ranges from 5.5 - 10.5 mg of hyperbaric bupivacaine
Given the difficulty of neuraxial access, we proceeded without spinal dose reduction, lest unsuccessful epidural placement
Observed appropriate and adequate spread, though decreased duration of surgical block
Patient did not experience neurologic injury or exacerbation of spinal stenosis symptoms at follow-up 4 weeks and 3 months postoperatively

Conclusion

Neuraxial anesthesia may offer a safe, alternative anesthetic to general anesthesia for selected achondroplastic patients
Titratable technique may be favored for greater control of block spread and duration

References

Dumitrascu CI, Eneh PN, Keim AA, Kraus MB, Sharpe EE. Anesthetic management of parturients with achondroplasia: a case series. Proc (Bayl Univ Med Cent). 2023 Dec 20;37(1):63-68. doi: 10.1080/08998280.2023.2261084. PMID: 38173994; PMCID: PMC10761160.
Kim JH, Woodruff BC, Girshin M. Anesthetic Considerations in Patients With Achondroplasia. Cureus. 2021 Jun 22;13(6):e15832. doi: 10.7759/cureus.15832. PMID: 34322329; PMCID: PMC8297512.
Renfree SP, Haglin J, Brinkman JC, Chung A. Exacerbation of Spinal Stenosis Symptoms Following Neuraxial Anesthesia in an Achondroplastic Cesarean Section. Cureus. 2023 Sep 13;15(9):e45170. doi: 10.7759/cureus.45170. PMID: 37842487; PMCID: PMC10575552.
Hebl JR, Horlocker TT, Kopp SL, Schroeder DR. Neuraxial Blockade in Patients with Preexisting Spinal Stenosis, Lumbar Disk Disease, or Prior Spine Surgery: Efficacy and Neurologic Complications. Anesthesia & Analgesia 111(6):p 1511-1519, December 2010. | DOI: 10.1213/ANE.0b013e3181f71234

SPINAL ANESTHESIA FOR TOTAL HIP ARTHROPLASTY IN AN ACHONDROPLASTIC PATIENT: A CASE STUDY