Toshihiko Nakatani

Lumbar sympathetic block for pain relief in two patients with interstitial cystitis

Background and Objectives Interstitial cystitis (IC) is characterized clinically by lower abdominal pain, pain during urination, and increased frequency of urination. Treatment of the symptoms in IC remains challenging. We report effective treatment using lumbar sympathetic block for 2 patients with IC. Case Report A 63-year-old and 78-year-old woman were diagnosed with IC. Medical therapy with nonsteroidal anti-inflammatory drugs (NSAID), anticholinergics, and hydrodistention of the bladder failed to improve their symptoms. Subsequently, a continuous lumbar epidural block using 1% mepivacaine was used in these patients. A transient reduction of the symptoms in both patients was achieved. A lumbar sympathetic block with a neurolytic agent produced almost complete, and long-lasting relief of their symptoms. Conclusion Lumbar sympathetic block using a neurolytic agent produced long-lasting pain relief in 2 patients with IC.

Breath-holding spells in somatoform disorder.

Breath-holding spells (BHS) are commonly seen in childhood. However, there are no case reports of BHS occurring in adolescents or young adults. We report two young adult cases and discuss the pathogensis, both physically and psychologically. BHS occurred for 1–2 minutes after hyperventilation accompanied by cyanosis in both cases. Oxygen saturation was markedly decreased. Each patient had shown distress and a regressed state psychologically. These cyanotic BHS occurred after hyperventilation, and we considered that a complex interplay of hyperventilation followed by expiratory apnea increased intrathoracic pressure and respiratory spasm. Breath-holding spells can occur beyond childhood.

Retention of finger blood flow against postural change as an indicator of successful sympathetic block in the upper limb

Background Sympathetic block in the upper limb has diagnostic, therapeutic and prognostic utility for disorders in the upper extremity that are associated with sympathetic disturbances. Increased skin temperature and decreased sweating are used to identify the adequacy of sympathetic block in the upper limb after stellate ganglion block (SGB). Baroreflexes elicited by postural change induce a reduction in peripheral blood flow by causing sympathetic vasoconstriction. We hypothesized that sympathetic block in the upper limb reduces the decrease in finger blood flow caused by baroreflexes stimulated by postural change from the supine to long sitting position. This study evaluated if sympathetic block of the upper limb affects the change in finger blood flow resulting from postural change. If change in finger blood flow would be kept against postural changes, it has a potential to be a new indicator of sympathetic blockade in the upper limb. Methods Subjects were adult patients who had a check-up at the Department of Pain Management in our university hospital over 2 years and 9 months from May 2012. We executed a total of 91 SGBs in nine patients (N=9), which included those requiring treatment for pain associated with herpes zoster in seven of the patients, tinnitus in one patient and upper limb pain in one patient. We checked for the following four signs after performing SGB: Horner’s sign, brachial nerve blockade, finger blood flow measured by a laser blood flow meter and skin temperature of the thumb measured by thermography, before and after SGB in the supine position and immediately after adopting the long sitting position. Results We executed a total of 91 SGBs in nine patients. Two SGBs were excluded from the analysis due to the absence of Horner’s sign. We divided 89 procedures into two groups according to elevation in skin temperature of the thumb: by over 1°C (sympathetic block group, n=62) and by <1°C (nonsympathetic block group, n=27). Finger blood flow decreased significantly just after a change in posture from the supine to long sitting position after SGB in both groups. In the sympathetic block group, the ratio of finger blood flow in the long sitting position/supine position with a change in posture significantly increased after SGB compared with before SGB (before SGB: range 0.09–0.94, median 0.53; after SGB: range 0.33–1.2, median 0.89, p<0.0001). Conclusion Our study shows that with sympathetic block in the upper limb, the ratio of finger blood flow significantly increases despite baroreflexes stimulated by postural change from the supine to long sitting position. Retention of finger blood flow against postural changes may be an indicator of sympathetic block in the upper limb after SGB or brachial plexus block.

Efficacy of Continuous Brachial Plexus Block for Intractable Cancer Pain in a Terminal Patient

We report a case of terminal cancer in which continuous peripheral nerve block provided effective relief for cancer-related pain that was difficult to control with pharmacotherapy. A 70-year-old woman with thyroid cancer, paraplegia due to multiple bone metastases, and cauliflower-like proliferation of skin metastasis on the left upper arm was receiving inpatient palliative care. Intractable pain during treatment of the tumor and when changing body position due to metastatic tumor and pathological fracture of the left humerus was difficult to control with pharmacotherapy. Continuous interscalene brachial plexus block was therefore performed, resulting in effective pain relief over the subsequent 38 days before death. Ultrasound-guided continuous peripheral nerve block can be performed at the bedside in patients in poor general condition who cannot tolerate neuraxial block, and should be considered in cases of terminal cancer patient suffering from intractable pain despite pharmacotherapy.

Fentanyl Tolerance in the Treatment of Cancer Pain: A Case of Successful Opioid Switching From Fentanyl to Oxycodone at a Reduced Equivalent Dose

ABSTRACT Opioids are not generally deemed to have an analgesic ceiling effect on cancer pain. However, there have been occasional reports of tolerance to opioid development induced by multiple doses of fentanyl. The authors report a case of suspected tolerance to the analgesic effect of opioid, in which an increasing dose of fentanyl failed to relieve the patients cancer pain symptoms, but opioid switching to oxycodone injections enabled a dose reduction to below the equivalent dose conversion ratio. The patient was a 60-year-old man diagnosed with pancreatic body carcinoma with multiple metastases. The base dose consisted of 12 mg/day of transdermal fentanyl patches (equivalent to 3.6 mg/day, 150 μg/h fentanyl injection), and rescue therapy consisted of 10 mg immediate-release oxycodone powders. Despite the total daily dose of fentanyl reaching 5.6 mg (equivalent to 560 mg oral morphine), the analgesic effect was inadequate; thus, an urgent adjustment was necessary. Due to the moderate dose of fentanyl, the switch to oxycodone injection was done incrementally at a daily dose equivalent to 25% of the fentanyl injection. The total dose of oxycodone was replaced approximately 53.5% of the dose of fentanyl prior to opioid switching.

Retention of Finger Blood Flow against Postural Change Has the Potential to Become a New Indicator of Sympathetic Block in the Upper Limb - A Preliminary Study

Introduction: Increased skin temperature and decreased sweating are used to identify the adequacy of sympathetic block in the upper limb. This, however, requires a thermography device to precisely evaluate skin temperature and a diaphoremeter to measure sweating. Baroreflexes elicited by postural change induce a reduction in peripheral blood flow to sustain systemic blood pressure and cerebral blood flow. We hypothesized that sympathetic blockade in the upper limb results in minimal changes in finger skin blood flow against postural change from the supine to sitting position. The aim of this study was to evaluate whether retention of finger blood flow against postural change can be used as a new indicator of sympathetic block in the upper limb. Methods: We tested for the following three signs after performing stellate ganglion block (SGB): Horner’s sign, brachial nerve blockade and finger blood flow, which was measured by a laser blood flow meter before and after SGB in the supine and immediately after adopting the sitting position. The criterion for determining effective sympathetic blockade in the upper limb was defined as follows: (Blood flow in the sitting position) / (Blood flow in the supine position) > 90%. Results: We executed a total of 80 SGBs in 7 patients. Two SGBs were excluded from analysis due to the absence of Horner’s sign. Brachial nerve blockade after SGB was absent in all patients. The criterion of (Blood flow in the sitting position) / (Blood flow in the supine position) > 90% was observed significantly more often on the SGB (45 cases) than non-SGB side (3 cases).

Characteristics of µ opioid receptor internalization caused by fentanyl in the rat spinal dorsal horn

Introduction: μ-opioid receptor (MOR) internalization is caused by (DAMGO) and etorphine, but not by morphine in vitro and in vivo. MOR internalization caused by fentanyl is demonstrated only in vitro. The relationship between MOR internalization and analgesic effect caused by fentanyl has not been studied. In addition, the role of MOR internalization caused by opioid agonists in the analgesic effect in vivo has not been well established. In the present study, therefore, we examined whether fentanyl causes MOR internalization in vivo or not and also studied the relationship between MOR internalization and analgesic effect of opioid agonists. Methods: The protocol was approved by our animal research and use committee. Male SpragueDawley rats weighing 300–330 g were implanted with intrathecal catheters at the level of L4–5. Tail flick test was performed at 30 min after intrathecal administration of morphine, DAMGO, fentanyl, or saline. Immediately after the test, rats were perfused and the spinal cord was removed. MOR distribution was assessed by immunohistochemical staining of MOR in the dorsal horn neurons. Results: The opioid agonists exerted analgesic effect assessed by tail flick test at 30 min after injection. In morphine treated rats, no MOR internalization was observed in the laminae I and II neurons of the spinal cord, as was seen with saline. DAMGO caused MOR internalization in almost all of the neurons expressing MOR. Though fentanyl also produced internalization in the laminae I and II neurons, the internalization was observed in approximately half of the neurons expressing MOR, and the distribution of internalized MOR was different from that induced by DAMGO. Conclusion: Intrathecally administered fentanyl caused MOR internalization in the rat spinal dorsal horn neurons. MOR distribution showed different patterns depending on opioid agonists used. These results suggest that the MOR internalization does not seem to be involved in analgesic effect produced by opioid agonist.

Assessment of postoperative pain: Contributing factors to the differences between patients and doctors

This study was undertaken to compare the assessment of pain intensity by 50 patients and by their doctors according to a visual analog scale 5 h and 20 h after major abdominal surgery, and to examine the relationships between the differences in rating of patients and doctors and the factors inherent in the patients which include preoperative expectation of pain, level of anxiety, and the surgical history of the patient. The ratings given by the patients were significantly higher than those given by the doctors at both time periods. However, the correlation between the ratings given by the two was low:r=0.31 andrs=0.27 at 5 h after the operations, andr=0.58 andrs=0.49 at 20 h. The results of analysis using Hayashis quantification theory Type II indicated a moderate association between the rating difference and the patients age, surgical history, preoperative state of anxiety, and expectation of pain. It is concluded that postoperative pain management, whether in clinical practice or in research, necessitates more consideration of the several above-mentioned individual factors and a preoperative interview in which the patients level of anxiety and the amount of information the patient has concerning the surgery and post-operative pain is clearly assessed.