Katsuyuki Moriwaki

Topographical features of cutaneous tactile hypoesthetic and hyperesthetic abnormalities in chronic pain

Tactile sensory abnormalities, such as tactile hypoesthesia and mechanical allodynia, are frequently present in patients with chronic pain. A growing body of evidence indicates that hyperesthetic phenomena, like mechanical allodynia, are at least in part due to altered processing by neurons in the CNS. We propose that the hyperesthesia is associated with a functional tactile hypoesthesia that is similarly mediated by altered processing by CNS neurons, and that this association is characterized by a particular topography that may be related to the receptive field organization of somatosensory CNS neurons. Moreover, we propose that the hyperesthetic-hypoesthetic association is dynamically modulated in tandem by pain input.

myofascial Pain in Patients With Postthoracotomy Pain Syndrome

Objective: Postthoracotomy pain syndrome is generally considered to be neuropathic pain due to intercostal nerve injury. However, nonneuropathic pain can also occur following thoracic surgery. We present a series of cases with postthoracotomy pain syndrome in which myofascial pain was thought to be a causative component of postthoracotomy pain syndrome. Case Report: Twenty‐seven patients (17 men and 10 women) were treated with trigger point injections, intercostal nerve blocks, and/or epidural blocks. Clinical criteria were used to diagnose the myofascial pain. A visual analogue scale was used, and sensory disturbances were recorded before and after treatment. A trigger point in a taut muscular band within the scapular region, which we diagnosed as myofascial pain, was observed in 67% of the patients. The existence of this trigger point significantly increased the rate of success for the treatments. Conclusions: Postthoracotomy pain may result, at least in part, from a nonneuropathic origin (myofascial pain). It is recommended that each patient be examined in detail to determine whether there is a trigger point in a taut muscular band within the scapular region. If found, this point is suggested as a good area for anesthetic injection.

Neuropathic pain and prolonged regional inflammation as two distinct symptomatological components in complex regional pain syndrome with patchy osteoporosis : a pilot study

Abstract To reappraise symptomatology of complex regional pain syndrome (CRPS), we investigated the clinical symptoms of seven patients with CRPS who showed associated patchy osteoporosis. The incidence of moderate to severe spontaneous pain, burning pain, mechanical allodynia was higher in patients with significant nerve injury than in those without. Periarticular tenderness adjacent to osteoporotic bones, abnormalities of blood flow, edema and impairment of motor function were seen in both groups of patients. Our clinical observations of patients with CRPS associated with patchy osteoporosis suggest that CRPS may have the following two distinct components: (1) neuropathic pain that includes severe spontaneous pain or severe persistent mechanical allodynia and (2) prolonged regional inflammation, the early phase of which could be indicated by positive inflammatory symptoms of pain (tenderness), heat, redness, swelling and loss of function and their alleviation with corticosteroids.

Osteoporosis following chronic constriction injury of sciatic nerve in rats

Abstract. Osteopathic changes sometimes occur in patients with complex regional pain syndrome (reflex sympathetic dystrophy and causalgia). We aimed to investigate whether such osteopathic changes occurred in rats with chronic constriction injury (CCI) of the sciatic nerve. A CCI of the sciatic nerve was established in a unilateral hind limb in 39 adult Sprague-Dawley rats, which were killed 1, 2, 3, 5, or 7 weeks after the CCI procedure. Bone mineral content (BMC) and bone mineral density (BMD) in extracted tibial bones were measured using a dual-energy X-ray absorptiometer, and the number of osteoclasts in the metaphyseal regions was counted by the use of tartrate-resistant acid phosphate (TRAP) staining. BMC was significantly decreased, compared with that of the contralateral side, 1 to 7 weeks after CCI, and BMD was decreased 2 to 7 weeks after the procedure in the ipsilateral tibial bones, compared with BMD in the contralateral bones. The number of TRAP-positive multinucleated osteoclasts in the ipsilateral bones was significantly increased at 2, 3, and 5 weeks after the CCI, when compared with the number of these osteoclasts in the contralateral bones. The results of the present study demonstrate that osteopathic changes are associated with chronic constrictive injury of the sciatic nerve.

Knee-chest position improves pulmonary oxygenation in elderly patients undergoing lower spinal surgery with spinal anesthesia

STUDY OBJECTIVE To define the effect of the knee-chest position on pulmonary oxygenation in patients who underwent lower spinal operations under spinal anesthesia. DESIGN Clinical, prospective study. SETTING Inpatient anesthesia and orthopedic surgery clinic at a municipal hospital. PATIENTS Fifty-six patients (30 males and 26 females) who underwent lower spinal surgery under spinal anesthesia. INTERVENTIONS After administering hyperbaric tetracaine solution and fixing the anesthesia level in the supine position for 15 minutes, patients were turned to the knee-chest position. They breathed room air normally. MEASUREMENTS AND MAIN RESULTS Arterial blood gas tensions were measured in the supine position 15 minutes after administration of the tetracaine solution and 15 minutes after turning patients to the knee-chest position. Patients were classified into six groups according to their age: patients in their teens and 20s, 30s, 40s, 50s, 60s, and 70s. In the supine position, the mean values of the alveolar arterial oxygen tension difference (A-aDO2) of patients in their 50s, 60s, and 70s were significantly higher than those of patients in their teens and 20s, 30s, and 40s. In the knee-chest position, these high values of A-aDO2 in the older patient groups decreased significantly, thereby eliminating any significant difference in A-aDO2 among all age groups. To determine the mechanism of the improvement of pulmonary oxygenation in the elderly patients, the effect of the knee-chest position on lung volumes was studied in eight young volunteers. CONCLUSION A significant improvement of pulmonary oxygenation was seen in elderly patients who underwent lower spinal operation with spinal anesthesia when they were turned to the knee-chest position. The knee-chest position has a beneficial effect on pulmonary oxygenation in elderly patients who are given spinal anesthesia.

Cardiac arrest after mesenteric manipulation in a patient undergoing abdominal surgery

A 55-yr-old, 72-kg man with both gastric and rectosigmoidal tumors was scheduled for rectosigmoidectomy. He was not taking medication, nor did he have a history of allergic reaction. Preoperative laboratory examinations were normal. After premeditation with 3 mg of bromazepam as suppository, anesthesia was induced with thiamylal200 mg, fentanyl 200 pg, and vecuronium 8 mg intravenously (IV) and was maintained with sevoflurane and nitrous oxide in oxygen. The surgery proceeded uneventfully, and the tumor was resected. Mesenteric manipulation was performed for abdominal lavage with warm saline at the end of surgery. Just after this procedure, ventricular premature beat appeared, systolic arterial pressure decreased from 102 to 58 mm Hg, and heart rate slowed from 72 to 48 bpm with ST segment elevation by 12 mm on heart monitor (Figure 1). Immediately, 12 mg of ephedrine and 0.5 mg of atropine were given, but cardiac arrest occurred. External cardiac massage and electric countershock resuscitated the patient. When the surgical dressings were removed after surgery, large dermal flares were observed on the trunk and extremities, but there were no respiratory symptoms. Blood samplings were taken to measure serum levels of histamine and mast cell tryptase (Tryptase RIACT kit; Pharmacia, Uppsala, Sweden); their normal ranges are 1.14 -C 0.40 nmol/L and less than 2.0 U/L, respectively (Figure 2). To determine whether anaphylactic reaction or mesenteric manipulation was responsible, dermal prick test and in vitro histamine release test were performed (Hollister-Stier, West Haven, CT) using all agents given before cardiac arrest; saline, thiamylal, fentanyl, vecuronium, chlorhexidine, lactated Ringer’s solution, and hydroxyethylated starch for dermal prick test and for in vitro histamine release test

Rocuronium-sugammadex use for electroconvulsive therapy in a hemodialysis patient: a case report

BackgroundRecently, rocuronium with subsequent use of sugammadex was proposed for electroconvulsive therapy (ECT) as an alternative to succinylcholine. Because sugammadex is cleared via the kidney with no metabolism, it is unknown that rocuronium-sugammadex use is safe in hemodialysis patients who received ECT.Case presentationIn this case report, we used rocuronium with subsequent administration of sugammadex in a 69-year-old female, hemodialysis patient, scheduled for ten ECT sessions for severe major depression. In the initial eight sessions, we tested the feasibility of rocuronium-sugammadex use for ECT. During the series of four ECT sessions, we measured plasma concentrations for the sum of sugammadex and sugammadex-rocuronium complex and observed whether possible residual sugammadex affected muscle relaxation during subsequent sessions of ECT. The results showed the feasibility of rocuronium-sugammadex use as muscle relaxants for ECT in patients undergoing hemodialysis. However, an accumulation of sugammadex did occur even after two sessions of hemodialysis, and residual sugammadex decreased the effect of the rocuronium given in the subsequent ECT sessions. Rocuronium-sugammadex was successfully utilized as muscle relaxants for ECT in this patient.ConclusionsOur experience in this case may indicate that if succinylcholine is contraindicated, rocuronium-sugammadex can be an alternative method for muscle relaxation during ECT in patients undergoing hemodialysis. When this rocuronium-sugammadex procedure is used, the effect of residual sugammadex after hemodialysis on the subsequently administered rocuronium should be considered.

Latent myofascial trigger points in paraspinal muscles of patients with chronic pain

AbstractWe have found a unique type of latent myofascial trigger point in the paraspinal muscles of patients with various chronic pain conditions, which has not been described previously. The myofascial trigger points are located in paraspinal muscles that shared the same or adjacent spinal nerves with the primary lesion causing the chronic pain condition. We also investigated the efficacy of trigger point injections to those points to alleviate the original pain. We reviewed 11 patients with such latent myofascial trigger points. Diagnosed chronic pain conditions included postthoracotomy pain syndrome, postherpetic neuralgia, cancer pain, radiculopathy, chronic abdominal wound pain, and chronic pancreatitis. Injections of local anesthetics to latent myofascial trigger points in the paraspinal muscles immediately reduced the intensity of the original pain in all patients. After the series of treatments, a visual analog scale showed a significant decrease of pain.

Effect of anhepatic phase of surgery using veno-venous bypass technique on plasma fentanyl concentration. Report of two cases.

We administered fentanyl continuously and measured its concentration in plasma in two patients undergoing surgery which produced an anhepatic phase using the veno-venous bypass technique; one patient had extracorporal liver resection and the other had venoplasty of the inferior vena cava and the right hepatic vein. The plasma fentanyl concentration increased during the anhepatic phase and decreased in the post-anhepatic phase in both cases. Though fentanyl has a wide safety margin, attention must be paid to such drug characteristics in the management of anaesthesia during the anhepatic phase.