Manipulations Under Anesthesia
MUA is a procedure that combines chiropractic adjustments and manipulations with general anesthesia or procedural sedation.11 The theory behind this strategy is that the anesthesia or sedation reduces pain and muscle spasm that may hinder the manipulation, allowing the practitioner to more effectively break up joint adhesions and reduce segmental dysfunction than if the patient had not undergone anesthesia.11
MUA is generally indicated in patients who have not responded to a 4- to 8-week trial of traditional manipulation therapy.12 It is also considered in patients who have "painful and restricting muscular guarding [that] interferes with the performance of spinal adjustments, mobilizations, and soft tissue release techniques."13
In the chiropractic literature, between 3% and 10% of patients are estimated to be candidates for MUA.12,14 It is not completely clear, however, what diagnoses are most likely to be treated successfully with this technique. Contraindications to MUA are generally the same as those for manipulation in conscious patients. A published list of contraindications from the Committee for Manipulation under Anesthesia (2003)15 included malignancy with bony metastasis, tuberculosis of the bone, recent fracture, acute arthritis, acute gout, diabetic neuropathy, syphilitic articular lesions, excessive spinal osteoporosis, disk fragmentation, direct nerve root impingement, and evidence of cord or caudal compression by tumor, ankylosis, or other space-occupying lesions.
MUA generally begins with deep procedural sedation, managed by an anesthesiologist. Once an adequate level of sedation is achieved, the manipulations are performed. Both high- and low-velocity thrusts are used, but it is recommended that the force exerted should be much less, and the manipulations performed with more caution, than in patients who are not anesthetized.12
For the thoracic spine, the patient is manipulated in the supine position with the arms crossed over the chest. The practitioner places one hand in a fist under the spine with the other hand on the patient's crossed arms, then delivers an anterior-to-posterior thrust. This is repeated until all affected segments have been treated.11,12
Literature to support the use of MUA for various indications is largely anecdotal. The largest published series13 is of 177 patients with chronic spinal pain who each underwent three MUA sessions followed by four to six weeks of traditional manipulations. The authors found that pain, as measured by visual analog scale, was reduced by 62% in patients with cervical spine pain, and by 60% in patients with lumbar pain. No adverse events were reported in the study.
Kohlbeck and Haldeman12 reviewed the reported complications of MUA across all published literature. They found that in 17 published papers, the overall complication rate was 0.7%, mainly represented by transitory increased pain. No spinal fractures were reported.
This case demonstrates a rare but serious complication of chiropractic MUA. It is unclear exactly what mechanism of injury led to an unstable thoracic spine fracture with massive hemothorax, and the precise cause will probably never be known. The clinicians who treated the case patient find it curious that the reported rate of adverse events following this procedure is so low, but they suspect an element of reporting bias in the chiropractic literature.
Conclusion
Iatrogenic injury after chiropractic manipulation is uncommon, but it can be devastating. Few serious complications of chiropractic MUA have been reported, but the literature is lacking in well-designed research studies. Despite the dearth of clinical trials to support its safety and efficacy, use of MUA has continued in the chiropractic community. This case demonstrates that serious adverse outcomes can occur, and more rigorous studies are needed to delineate the true benefits and risks of this set of chiropractic procedures.