Radiofrequency procedures.

Radiofrequency is a minimally invasive, target-selective technique that has been in clinical use for more than 25 years and has demonstrated success at reducing pain in several chronic pain conditions, including trigeminal neuralgia, chronic low back pain, postherpetic neuralgia, and complex regional pain syndrome. However, the success of radiofrequency in chronic pain has not been adequately reproduced in good-quality, randomized controlled trials, and its use in the management of neuropathic pain is under some debate. In addition, conventional radiofrequency occasionally leads to worsening and even new onset of neuropathic pain. Nevertheless, clinical experience suggests that radiofrequency may be a useful tool in the overall management of refractory neuropathic pain. Pulsed radiofrequency in particular is a minimally destructive procedure that may offer new opportunities and a broader perspective for therapy with radiofrequency.

Evolution of epidural lysis of adhesions.

Epidural neuroplasty (lysis of epidural adhesions) is an interventional technique that has emerged over the last 10 years as part of a multidisciplinary approach to treating radiculopathy with low back pain when conservative management has failed. Neuroplasty was at one time performed as a single-catheter technique using the caudal approach. It now has many variations, including placement of the catheter tip in the anterior epidural space. This article will discuss the evolution and refinement of epidural neuroplasty at our institution.

Percutaneous epidural neuroplasty: prospective evaluation of 0.9% NaCl versus 10% NaCl with or without hyaluronidase.

BACKGROUND AND OBJECTIVES: Percutaneous epidural neuroplasty (epidural neurolysis, lysis of epidural adhesions) is an interventional pain management technique that has emerged over approximately the last 10 years as part of a multidisciplinary approach to treating radiculopathy with low back pain. In addition to local anesthetic and corticosteroid, hypertonic saline (10% NaCl) and hyaluronidase are used for the technique. The objective of this study was to determine if hypertonic saline or hyaluronidase influenced treatment outcomes. METHODS: Eighty-three subjects with radiculopathy plus low back pain were assigned to one of four epidural neuroplasty treatment groups: (a) hypertonic saline plus hyaluronidase, (b) hypertonic saline, (b) isotonic saline (0.9% NaCl), or (d) isotonic saline plus hyaluronidase. Subjects in all treatment groups received epidural corticosteroid and local anesthetic. RESULTS: Twenty-four subjects did not complete the study. Most of the other 59 subjects receiving any of the four treatments as part of their pain management obtained significant relief immediately after treatment. Visual analog scale (VAS) scores for the area of maximal pain (VASmax; back or leg) were reduced in 25% or more of subjects in all treatment groups at all post-treatment follow-up times (1, 3, 6, 9, and 12 months). A smaller fraction of subjects treated with hypertonic saline or hyaluronidase and hypertonic saline required more additional treatments than did subjects receiving the other treatments. CONCLUSIONS: Percutaneous epidural neuroplasty, as part of an overall pain management strategy, reduces pain (sometimes for over one year) in 25% or more of subjects with radiculopathy plus low back pain refractory to conventional therapies. The use of hypertonic saline may reduce the number of patients that require additional treatments.

Clinical realities and economic considerations: efficacy of intrathecal pain therapy.

Studies of analgesia in cancer patients have revealed that intrathecal administration of opioids can deliver potent analgesia with fewer systemic side effects than equivalent doses of systemic opioids. In addition, several trials have examined the safety and efficacy of this modality in patients with pain of nonmalignant origin. In one survey of 35 physicians involving 429 patients treated with intrathecal therapy, physician reports of global pain relief scores were excellent in 52.4% of patients, good in 42.9%, and poor in 4.8%. In another study of 120 patients, the mean pain intensity score had fallen from 93.6 to 30.5 six months after initiation of therapy. In both studies, patients reported significant improvement in activities of daily living, quality of life measures, and satisfaction with the therapy. Constipation, urinary retention, nausea, vomiting, and pruritus are typical early adverse effects of intrathecal morphine and are readily managed symptomatically. Other potential adverse effects include amenorrhea, loss of libido, edema, respiratory depression, and technical issues with the intrathecal system.

Thermal grill illusion and complex regional pain syndrome type I (reflex sympathetic dystrophy).

BACKGROUND AND OBJECTIVES: In normal humans, placing a hand on a thermal grill containing warm elements separated by cool ones produces a burning sensation. In this case report, responses to a thermal grill in a patient with neuropathic pain were examined. METHODS: The responses of a 31-year-old woman with complex regional pain syndrome type I (reflex sympathetic dystrophy) to a thermal grill were evaluated before and after stellate ganglion block. RESULTS: The patient experienced a burning sensation when the unaffected hand was placed on the grill and could distinguish which element was warm and which was cool. An intolerable burning sensation caused the patient to quickly (within 4 seconds) withdraw the affected hand when it was placed on the grill. Touching cool elements with the affected hand produced an intense burning sensation (cold allodynia), whereas touching warm elements produced a pleasant warm sensation. Stellate ganglion block with phenol, local anesthetic, and steroid resulted in long-lasting absence of cold allodynia. CONCLUSION: The thermal grill may be a useful a tool to help understand the pathophysiology of complex regional pain syndrome type I.

General anesthesia for cesarean section in a parturient with a single ventricle and pulmonary atresia.

The successful management of a cesarean section in a parturient with a single ventricle and pulmonary atresia using general anesthesia is discussed. After cyanosis at birth, the patient underwent cardiac catheterization, which showed an apparent severe tetralogy of Fallot, atresia of the main pulmonary artery (PA), and a large patent ductus arteriosus. When she was 7 months of age, a Blalock-Taussig shunt (right subclavian artery to right PA) was done. She remained stable until age 11, when cyanosis increased and exercise tolerance decreased. Recatheterization more clearly defined the lesion: closed shunt, pulmonary valvular atresia, severe ductal stenosis, reduced pulmonary flow, double-outlet right ventricle, and severe hypoplasia of the left atrium, mitral valve, and left ventricle. A Potts shunt (left descending aorta to left PA) was done. Compliance with therapy was poor and follow-up difficult. Exercise tolerance was poor, but the patient remained otherwise stable. At 28 weeks' gestation, this 23-year-old parturient presented with severe congestive heart failure (CHF). After initial therapy with oxygen, bed rest, digoxin, and diuretics, she improved and remained stable for a month. At that time (32 weeks' gestation), CHF worsened. Because the cervix was unfavorable for a vaginal delivery, a cesarean section was planned. The patient was then taken to the operating room electively, and an opioid-based general anesthetic was administered. Both mother and infant did well. This case is presented because the physiology of the patient's lesion and her unusual social history presented challenges for her anesthetic management.

Hyperkalaemia: a complication of warm heart surgery.

A case is presented of hyperkalaemia (13.6 mEq.L-1) occurring during cardiopulmonary bypass using warm blood cardioplegia (K+ 40-60 mEq.L-1). Treatment with epinephrine, calcium chloride, sodium bicarbonate, and furosemide reduced K+ to 6.5 mEq.L-1 within 30 min and myocardial performance was enhanced with amrinone and cardiac rhythm was controlled with A-V segmental pacing. It is believed that the hyperkalaemia resulted from a combination of the surgical procedure (mitral valve replacement) and the use of warm cardioplegia. The purpose of this report is to increase the awareness of the possibility of hyperkalaemia with warm cardioplegia and to describe a successful therapeutic regimen.

Backache after extradural anaesthesia in the postpartum period: dissection of thoracic aneurysm.

We describe a case of postpartum ruptured dissecting aneurysm of the thoracic aorta, unrelated to the anaesthetic management with extradural anaesthesia. This complication is discussed in detail, as the anaesthetist may be the specialist required to respond to the common presenting symptom of severe back pain.

Loss of consciousness after emergence from anaesthesia. A case of suspected micturition syncope.

A case of postanaesthesia micturition syncope with respiratory arrest is described. If syncope occurs, the temporary myocardial ischaemia and cerebral hypoperfusion may increase anaesthetic risk in the marginally compensated patient. The loss of airway protection during the syncopal period is also a cause of concern. We recommend the use of an indwelling bladder catheter during any prolonged surgical procedure.

Pain management of the oncologic patient.

After the first 5 years of life, cancer is one of the three most common causes of death. Most investigations of cancer pain have shown that 50-70% of patients suffer needlessly. Pain may be due to the tumor or a co-existant benign pain syndrome. Methods of pain management include: 1) neurolytic blockade: stellate ganglion block, celiac plexus block, lumbar sympathetic block, epidural phenol, subarachnoid neurolysis; and 2) non-pharmacologic methods: radiofrequency thermocoagulation lumbar sympathectomy, transcutaneous nerve stimulation (TENS), dorsal column stimulation (DCS). In summary, we utilize every possible combination of therapeutic modalities for cancer pain management. With so many safe procedures available, we encourage the primary physician to refer patients early in their disease process. Neurolytic procedures should be performed prior to initiation of high dose narcotic therapy, radiation, chemotherapy, and surgery when possible.

Percutaneous dorsal column stimulator for chronic pain control.

This is a retrospective review of 26 patients with chronic intractable pain in which dorsal column stimulation was used as a salvage procedure. On follow-up of 12 to 42.7 months, 21 of the patients had diminished narcotic usage. Seventeen patients subjectively rated their pain relief as good to excellent. Another five patients reported some relief of pain. Two-thirds of the patients reported an increase in their ability to perform daily activities such as walking, stair climbing, and time spent sitting. There are still many technical problems that plague this procedure, as evidenced by a very high technical complication rate of lead migration and lead breakage. Whether or not results diminish over long-term follow-up remains to be seen.