PubMed Health⌕ Search

Biomedical subjects

Steven P Cohen

Publications and source records attributed to Steven P Cohen.

At least 19 recordsLinked to original sources

The intravenous ketamine test predicts subsequent response to an oral dextromethorphan treatment regimen in fibromyalgia patients.

UNLABELLED: Fibromyalgia (FM) is a challenging pain syndrome for which no reliable pharmacologic treatment exists. Recent clinical studies suggest that N-methyl-D-aspartate receptors might play a role in the pathogenesis of this disorder. To determine whether an intravenous (IV) ketamine test predicts the response to a therapeutic trial with an oral N-methyl-D-aspartate receptor antagonist, we performed a low-dose (0.1 mg/kg) IV ketamine infusion on 34 consecutive patients with FM, which was subsequently followed by an oral dextromethorphan (DX) treatment regimen. As per previous guidelines, the cutoff value for a positive response to the IV ketamine test was designated to be 67% pain relief, and a positive response to DX treatment was 50% pain reduction at 4- to 6-week follow-up visits. The degree of correlation between pain relief with ketamine and DX was highly significant (Pearson correlation coefficient, 0.66; P < .001). Ten patients responded positively to both ketamine and DX, 19 responded to neither drug, 3 had a positive response to ketamine but not DX, and 2 obtained good pain relief with DX but not ketamine. The sensitivity of the IV ketamine test was 83%, the specificity was 86%, the positive predictive value was 77%, and the negative predictive value was 91%. An association was also found between the development of side effects to the two treatments. PERSPECTIVE: The response to an IV ketamine infusion was found to predict the subsequent response to an oral dextromethorphan treatment regimen in fibromyalgia patients, with an observed agreement of 83%. Considering the refractory nature of fibromyalgia to conventional pain treatments, the IV ketamine test might enhance patient care by saving time and reducing unnecessary treatment trials.

Administration, Oral↗

Pulsed radiofrequency of the dorsal root ganglia is superior to pharmacotherapy or pulsed radiofrequency of the intercostal nerves in the treatment of chronic postsurgical thoracic pain.

BACKGROUND: Chronic postsurgical thoracic pain (CPTP) represents a major therapeutic challenge characterized by an absence of clinical studies to guide treatment. Recently, the implementation of pulsed radiofrequency (RF) has generated intense interest in the medical community as a safe and potentially effective treatment for neuropathic pain. To date, there are no studies comparing pulsed RF to more conventional therapeutic modalities for any pain condition. OBJECTIVES: To compare treatment outcomes between pharmacotherapy, pulsed RF of the intercostal nerves (ICN) and pulsed RF of the dorsal root ganglia (DRG) in CPTP. METHODS: Retrospective data analysis involving 49 patients. RESULTS: At 6-week follow-up, 61.5% of the pulsed RF DRG group reported > or =50% pain relief vs. 27.3% in the medical management (MM) group and 21.4% in the IC group (P = 0.12). At 3-month follow-up, 53.8% in the DRG group continued to report > or = 50% pain relief vs. 19.9% in the MM and 6.7% in the ICN groups, respectively (P = 0.02). Among the pulsed RF patients who did report a successful outcome, the mean duration of pain relief was 2.87 months in the ICN group and 4.74 months in the DRG group (P = 0.01). CONCLUSIONS: Pulsed RF of the DRG was a superior treatment to pharmacotherapy and pulsed RF of the ICN in patients with CPTP. Prospective studies are needed to confirm these results and identify the best candidates for this treatment.

Adult↗

Pronounced unexplained preoperative tachycardia heralding serious cardiac events: a series of three cases.

PURPOSE: Pronounced, unexplained preoperative tachycardia can be a formidable challenge for the anesthesiologist. Whereas the relationship between persistent intraoperative tachycardia and perioperative morbidity is indisputable, there is a lack of available data on unexplained preoperative tachycardia. The main objective of this case series is to stimulate research and discussion on this topic, so that guidelines can be developed to aid in management. CLINICAL FEATURES: We present three patients with pronounced (> or = 130 beats x min(-1)) unexplained preoperative tachycardia who suffered adverse perioperative events that were garnered from quality improvement records at two teaching hospitals. In the first case, a 38-yr-old woman with a lumbar spinal tumour went into ventricular fibrillation after induction of anesthesia and was found on subsequent evaluation to have an abnormal cardiac re-entrant pathway. In the second case, an otherwise healthy middle-aged man developed a wide complex tachycardia with hypotension during foot surgery, with the subsequent cardiac evaluation being negative. In the third case, a young, healthy woman scheduled for a melanoma incision developed crushing, substernal chest pain accompanied by nausea and shortness of valve prolapse with regurgitation. Before rescheduling the procedures, therapeutic interventions were undertaken that facilitated successful completion of the surgeries. CONCLUSIONS: There are currently no data regarding the prevalence of unexplained preoperative tachycardia, and no guidelines to direct management. More research is needed on this important topic, including epidemiological data and management algorithm(s).

Adult↗

Nucleoplasty with or without intradiscal electrothermal therapy (IDET) as a treatment for lumbar herniated disc.

BACKGROUND AND OBJECTIVE: In industrialized societies, the prevalence of radicular low back pain has exploded in recent years. The growing economic and personal costs of this challenging entity have led to the development of a wide array of new treatments, ranging from pharmacotherapy with neuropathic medications to open surgical treatment. Among the therapeutic options to emerge are a plethora of minimally invasive treatments aimed at removing nuclear material and lowering intradiscal pressure through devices inserted percutaneously into intervertebral discs. Yet there is a compelling lack of clinical evidence to support the use of these procedures. This study was undertaken to determine the treatment outcomes of 16 consecutive patients with lumbar radicular pain secondary to a herniated disc who underwent nucleoplasty as their primary therapy. METHODS: Included in this series were nine patients with significant axial back pain, sitting intolerance, and positive discography who also underwent intradiscal electrothermal therapy (IDET). Among the 7 patients who only had nucleoplasty, 4 had 2 discs treated and 3 had 1 disc. In the 9 patients who also had IDET, 6 had 1 disc treated and 3 had 2 discs treated. Of the 32 total disc treatments, 20 were at L5-S1, 10 were at L4-5 and 2, one each for IDET and nucleoplasty, were at L3-4. RESULTS: In the overall cohort, the average Visual Analogue Scale (VAS) pain score decreased from 6.7 to 5.6 at a mean follow-up of 9 months. In the seven patients who underwent only nucleoplasty, the mean VAS score decreased from 6.0 to 4.8. Only one patient reported a >/=50% reduction in pain score. CONCLUSIONS: We conclude that with use of the present selection criteria, nucleoplasty is not an effective long-term treatment for lumbar radiculopathy, either alone or with IDET. Before conducting future clinical trials, we recommend modifying these criteria to include only those patients with small (<6-mm) contained disc herniations whose annular integrity is documented by computed tomography discography and corresponding radicular symptoms confirmed by either selective nerve root blocks or electromyography and nerve conduction studies.

Adult↗

Presentation, diagnoses, mechanisms of injury, and treatment of soldiers injured in Operation Iraqi Freedom: an epidemiological study conducted at two military pain management centers.

UNLABELLED: In recent military conflicts the major source of soldier attrition has not been battle injuries but more mundane causes similar to those encountered in civilian life. In an effort to determine the pain conditions affecting soldiers during wartime, we conducted an observational study among 162 soldiers medically evacuated from Operation Iraqi Freedom who were referred to 2 large pain treatment centers located outside the theaters of combat. Fifty-three percent of soldiers presented with either radicular (n = 49) or axial (n = 37) low back pain, with lumbar herniated disk being the most frequently diagnosed condition (24%). The two most implicated etiologies were exacerbation of a previous pain condition treated with surgery (15%) and motor vehicle accidents(12%). Only 17% of patients were injured during battle. Seventy-two percent of soldiers received at least one nerve block/injection, the most common of which was lumbar epidural steroid administration (22%). Nonsteroidal antiinflammatory drugs were prescribed to 56% of patients, opioids to 49%, and some form of alternative therapy to 17%. Among the 49 patients in whom data were available, only 2% returned to combat duty in Iraq. With the exception of battle-related injuries, the pain conditions suffered during modern warfare seem to be similar to those encountered in civilian pain clinics. To improve the return-to-duty rate, better preventive measures and more aggressive treatment conducted in forward-deployed medical units are recommended. IMPLICATIONS: We conducted an observational study at two large military pain treatment centers among soldiers injured in Operation Iraqi Freedom. Fifty-three percent of soldiers presented with low back pain, with lumbar herniated disk being the most common diagnosis. Only 2% of patients returned to combat duty in Iraq. To improve the return-to-duty rate, better preventive measures and more aggressive treatment in forward-deployed medical units are recommended.

Adult↗

Sacroiliac joint pain: a comprehensive review of anatomy, diagnosis, and treatment.

Sacroiliac (SI) joint pain is a challenging condition affecting 15% to 25% of patients with axial low back pain, for which there is no standard long-term treatment. Recent studies have demonstrated that historical and physical examination findings and radiological imaging are insufficient to diagnose SI joint pain. The most commonly used method to diagnose the SI joint as a pain generator is with small-volume local anesthetic blocks, although the validity of this practice remains unproven. In the present review I provide a comprehensive review of the anatomy, function, and mechanisms of injury of the SI joint, along with a systematic assessment of its diagnosis and treatment.

Arthralgia↗

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↗

Pain management in trauma patients.

Trauma is a major cause of mortality throughout the world. In recent years, major advances have been made in the management of trauma, the end result of which has been reduced mortality and enhanced function. One of these areas is pain control. Improved pain management has not only led to increased comfort in trauma patients, but has also been shown to reduce morbidity and improve long-term outcomes. This review focuses on the treatment of pain in the setting of acute injury and on pain management in trauma patients who go on to develop chronic pain. Emphasis is placed on pharmacologic interventions, invasive and noninvasive pain management techniques, analgesia in challenging patients, and pain control in commonly encountered trauma conditions.

Amputation Stumps↗

Lumbar puncture associated with pneumocephalus: report of a case.

UNLABELLED: Pneumocephalus is a well known complication of spinal and epidural anesthesia, but it is extremely rare after diagnostic or therapeutic lumbar puncture. This uncommonness can obscure the clinical diagnosis and lead to unnecessary procedures and prolonged patient discomfort. We report a 72-yr-old woman with normal pressure hydrocephalus who underwent an unremarkable lumbar puncture that was complicated by a postprocedure pneumocephalus that manifested as a continuous headache. The pneumocephalus resolved spontaneously after 4 days. Possible mechanisms for this occurrence, along with steps that can be taken to prevent this complication, are discussed. IMPLICATIONS: We report a case of symptomatic pneumocephalus in a woman with normal pressure hydrocephalus after an unremarkable lumbar puncture. The possible mechanisms for this occurrence, along with steps that can be taken to prevent this complication, are discussed.

Aged↗

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↗

The causes of false-positive medial branch (facet joint) blocks in soldiers and retirees.

OBJECTIVE: The purpose of this study was to determine the factors associated with false-positive medial branch blocks (MBB), the nerve blocks used to diagnose facet arthropathy, in soldiers and retirees. METHODS: The study subjects were 78 patients with chronic low back pain who underwent diagnostic MBB to determine whether or not the facet joints were pain generators. Radiofrequency denervation of these nerves was performed in all patients with positive responses. Patients who failed to obtain pain relief after the blocks (negative blocks) and those who obtained temporary pain relief after MBB but failed radiofrequency denervation (false-positive blocks) then proceeded to undergo discography. Based on patients' responses to diagnostic blocks, discography results, the presence of radicular pain, and previous back surgery, the data were analyzed to determine whether any of these variables correlated with false-positive MBB. RESULTS: The presence of discogenic or radicular pain was not associated with a higher false-positive response rate to MBB. Conversely, the absence of discogenic pain was associated with a higher percentage of false-positive blocks. There was also a trend for patients with previous back surgery to have a higher false-positive rate than those who had not undergone previous surgery. CONCLUSIONS: Although a high incidence of epidural and foraminal spread occurs during the performance of MBB, this is unlikely to be a significant cause of false-positive blocks.

Adult↗

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↗

Pulsed radiofrequency as a treatment for groin pain and orchialgia.

Inguinal and testicular pain are challenging problems for which no reliable, standardized treatment exists. We report 3 patients with groin pain or orchialgia who were treated with pulsed radiofrequency of the nerves innervating these areas. All 3 patients reported complete pain relief at their 6-month follow-up visits. The techniques and settings used for the nerve blocks and radiofrequency procedures are explained in detail, along with a brief synopsis of the rationale for using it. Randomized, placebo-controlled studies are needed to better assess the efficacy of this procedure and identify eligible candidates.

Adult↗