Biomedical subjects

Thomas Larkin

Publications and source records attributed to Thomas Larkin.

5 recordsLinked to original sources

PubMed2004

Sedation with ketamine during intradiscal electrothermal therapy.

STUDY DESIGN: A technical report. OBJECTIVES: To present a new and improved method to sedate patients during intradiscal electrothermal therapy (IDET). SUMMARY OF BACKGROUND DATA: The current standard of practice is to sedate patients with short-acting benzodiazepines and opioids during the coagulation phase of intradiscal electrothermal therapy. There are few data on the subject, but it is estimated that between 5% and 20% of IDET procedures are either aborted early or switched to a lower heating temperature because patients cannot tolerate the optimal, recommended heating protocol. A priori, one must assume these patients are more likely to fail their treatment than those who are able to tolerate complete heating. METHODS: The authors treated 9 patients receiving intradiscal electrothermal therapy who were unable to tolerate the latter portion of their heating protocol secondary to axial low back pain despite high doses of opioids, with low dose ketamine. This paper outlines our experience with "rescue" doses of ketamine, along with the rationale and guidelines for its use. RESULTS: After receiving ketamine, all patients were able to complete the full intradiscal electrothermal therapy heating protocol. The rescue dosages of ketamine ranged from 15 to 55 mg. The dosages of midazolam used to prevent the psychomimetic effects of ketamine ranged from 3 to 7 mg. Oxygen saturation and hemodynamic parameters did not change significantly after ketamine was administered, and all patients remained responsive throughout the procedure. There were no adverse effects or complications reported. CONCLUSIONS: When used judiciously to treat axial back pain during intradiscal electrothermal therapy heating, ketamine is a safe and effective rescue medication.

Adult↗

PubMed2004

The intravenous ketamine test: a predictive response tool for oral dextromethorphan treatment in neuropathic pain.

IV infusion tests performed to predict subsequent response to oral analgesics are an increasingly popular method used to enhance medical care and conserve resources. Because no infusion test is completely accurate, the potential benefits of these tests must be weighed against the frustration and waste in resources encountered with false-positive results, and the failure to use a potentially beneficial treatment with false-negative results. In recent years, drugs that act antagonistically at N-methyl-d-aspartate receptors have been shown to be valuable adjuncts in the treatment of pain. To determine the predictive value of small-dose (0.1 mg/kg) IV ketamine on an oral dextromethorphan (DX) treatment regimen, we analyzed the analgesic response to these drugs in 25 patients at 2 tertiary care military treatment facilities, institutions at which DX is not readily accessible. When >/=50% response for both drugs was used as the outcome measure for success, the positive predictive value of the ketamine test was 64%, the negative predictive value 73%, and the observed agreement 68%. However, when >/=67% relief with ketamine was used as an outcome measure (as determined by a receiver operating characteristic curve), the positive predictive value was 90%, the negative predictive value 80%, and the observed agreement increased to 84%. Based on these results, we conclude that an IV ketamine test may be useful in predicting response to oral DX. More research is needed to determine the ideal candidates for such a test, and the optimal dose and cutoff value for the response to ketamine.

Administration, Oral↗

PubMed2003

Risk factors for failure and complications of intradiscal electrothermal therapy: a pilot study.

STUDY DESIGN: A bi-institutional, retrospective clinical data analysis. OBJECTIVES: To determine risk factors for failure and complications of intradiscal electrothermal therapy, a treatment for discogenic back pain. SUMMARY OF THE BACKGROUND DATA: Intradiscal electrothermal therapy is a relatively new treatment for discogenic back pain. Though previous studies have shown it to be an effective treatment, there are few published studies examining complications and none examining risk factors for failure. METHODS: The authors treated 79 patients with discogenic back pain using intradiscal electrothermal therapy. Complications were assessed by patient report and, when indicated, further diagnostic testing. Success or failure was determined by visual analogue pain scores at 6-month follow-up. Variables examined for their relationship to failure and complications were age, sex, duration of pain, number of levels heated, smoking history, diabetes, obesity, leg pain, and previous back surgery. RESULTS: Forty-eight percent of patients reported more than 50% pain relief at their 6-month follow-up. There were eight complications (10%), most of which were self-limited and transient. The only risk factor associated with intradiscal electrothermal therapy failure was obesity (P = 0.01). Whereas 54% of nonobese patients reported good pain relief at 6 months, only one out of 10 obese patients had successful intradiscal electrothermal therapy. The obese patients in our study were more likely to have a complication from intradiscal electrothermal therapy than they were to obtain pain relief. CONCLUSION: The only risk factor found to be associated with IDET outcome was obesity, which was a strong predictor of failure. Obesity should be considered a relative contraindication to performing IDET.

Adolescent↗

PubMed2002

Does needle insertion site affect diskography results? A retrospective analysis.

STUDY DESIGN: A retrospective clinical data analysis was performed. OBJECTIVES: To determine the effect of needle insertion site on provocative diskography results, and to ascertain whether performing diskography ipsilaterally to a patient's reported pain leads to a higher rate of false-positives. SUMMARY OF BACKGROUND DATA: In certain groups of patients, provocative diskography is associated with a significant false-positive rate, which can lead to misdiagnosis and inappropriate treatment. Although purported by some to be a cause of false-positive diskogram results, the effect of needle insertion site on diskography results has yet to be determined. METHODS: The charts of 127 patients who underwent diskography were evaluated to determine the relationship between the location of pain, needle insertion site, and diskography results. RESULTS: Performing diskography on the side ipsilateral to a patient's pain did not result in a higher incidence of positive diskogram results. CONCLUSION: False-positive diskography results are unlikely to result from performing the procedure on the same side as a patient's reported pain.

Adult↗

PubMed2002

A giant herniated disc following intradiscal electrothermal therapy.

The introduction of intradiscal electrothermal therapy for the management of discogenic back pain has been met with intense interest over the past few years. During this time there have been several noncontrolled studies published on the procedure, most of which have shown excellent outcomes but few, if any, complications. The authors describe a 29-year-old, 152-kg active duty male soldier who underwent two-level intradiscal electrothermal therapy for L4-L5 and L5-S1 discogenic pain. Before the procedure, the patient had a small L5-S1 contained herniation, with no signs of radiculitis. Postprocedure, the patient developed radicular symptoms and was noted on MRI to have a large L5-S1 disc herniation effacing the left S1 nerve root. Follow-up discography revealed a negative discogram at L4-L5. The patient proceeded to undergo a single-level lumbar fusion, which resulted in nearly complete relief of his radicular and axial low back pain. Two years post-surgery, he is off all narcotic medications and continues to work full-time as a soldier. This case illustrates both the potential benefits and complications that may be associated with intradiscal electrothermal therapy.

Adult↗