Chia-Shiang Lin

L-type calcium channels are involved in mediating the anti-inflammatory effects of magnesium sulphate

BACKGROUND Magnesium sulphate (MgSO(4)) has potent anti-inflammatory capacity. It is a natural calcium antagonist and a potent L-type calcium channel inhibitor. We sought to elucidate the possible role of calcium, the L-type calcium channels, or both in mediating the anti-inflammatory effects of MgSO(4). METHODS RAW264.7 cells, an immortalized murine macrophage-like cell line, were treated with phosphate buffered saline, MgSO(4), lipopolysaccharide (LPS), LPS plus MgSO(4), LPS plus MgSO(4) plus extra-cellular supplement with calcium chloride (CaCl(2)), or LPS plus MgSO(4) plus the L-type calcium channel activator BAY-K8644. After harvesting, the production of inflammatory molecules was evaluated. Because the production of endotoxin-induced inflammatory molecules is regulated by the crucial transcription factor nuclear factor (NF)-kappaB, we also evaluated the expression of NF-kappaB. RESULTS LPS significantly induced the production of inflammatory molecules, including macrophage inflammatory protein-2, tumour necrosis factor-alpha, interleukin (IL)-1beta, IL-6, nitric oxide/inducible nitric oxide synthase, and prostaglandin E(2)/cyclo-oxygenase-2. LPS also induced NF-kappaB activation, as inhibitor-kappaB degradation, NF-kappaB nuclear translocation, and NF-kappaB-DNA binding activity were significantly increased in LPS-treated RAW264.7 cells. MgSO(4), in contrast, significantly inhibited the LPS-induced inflammatory molecules production and NF-kappaB activation. Moreover, the effects of MgSO(4) on inflammatory molecules and NF-kappaB were reversed by extra-cellular calcium supplement with CaCl(2) and L-type calcium channel activator BAY-K8644. CONCLUSIONS MgSO(4) significantly inhibited endotoxin-induced up-regulation of inflammatory molecules and NF-kappaB activation in activated RAW264.7 cells. The effects of MgSO(4) on inflammatory molecules and NF-kappaB may involve antagonizing calcium, inhibiting the L-type calcium channels, or both.

Premedication with mirtazapine reduces preoperative anxiety and postoperative nausea and vomiting.

BACKGROUND:Mirtazapine is a new antidepressant that blocks 5-HT2 and 5-HT3 receptors. With this receptor profile, it is possible that mirtazapine could provide both anxiolysis and efficacy for postoperative nausea and vomiting (PONV). We therefore tested the hypothesis that premedication with mirtazapine can reduce preoperative anxiety and PONV. METHODS:Eighty female patients with at least two PONV risk factors scheduled for gynecological surgery were enrolled. Dexamethasone 8 mg was given before induction of anesthesia and patients were randomly assigned to group M + D (mirtazapine plus dexamethasone) or group dexamethasone. An oral disintegrating mirtazapine 30 mg or placebo tablet was given 1 h before surgery. Preoperative anxiety level was assessed by a visual analog scale (VAS) before mirtazapine administration and 1 h thereafter. General anesthesia was induced with 1% propofol at the rate of 200 mL/h (until loss of consciousness) and was then maintained with sevoflurane in oxygen and air. An auditory evoked potentials index monitor was used to titrate sevoflurane. The incidence of PONV, the use of rescue antiemetic, complete response, postoperative Ramsay Sedation Scores, and VAS pain scores were assessed 1, 2, and 24 h after surgery and compared. RESULTS:The VAS anxiety scale was lower in group M + D after mirtazapine administration. There were no differences in the induction dose of propofol, the concentrations of sevoflurane during anesthesia, and recovery times between the two groups. The incidence of complete response to PONV over 0–24 h was lower in group M + D (80% vs 50%, P < 0.01). CONCLUSIONS:Premedication with mirtazapine 30 mg reduces the level of preoperative anxiety and the risk of PONV in moderate and high-risk female patients.

Treating a patient with intractable paralytic ileus using thoracic epidural analgesia

Postoperative ileus is considered an undesirable response to major abdominal surgery that leads to discomfort, complications, morbidity, and the prolongation of hospital stays. Although thoracic epidural analgesia has been introduced to prevent and/or reduce postoperative ileus, it is rarely used as a way to treat postoperative ileus. A 65-year-old man developed paralytic ileus after undergoing a colectomy. Despite conservative and surgical management, postoperative morbidity persisted. A continuous infusion of 0.2% levobupivacaine at a rate of 4 mL/hour was administered for 4 days via a thoracic epidural catheter that had been percutaneously tunneled into the T11-T12 epidural space. With this treatment, daily drainage from a nasogastric tube was gradually decreased and flatus was noted. A week later, the patient could start receiving a liquid diet. Therefore, thoracic epidural analgesia can be used to treat or alleviate paralytic ileus.

Intrathecal gabapentin does not act as a hyperpolarization- activated cyclic nucleotide-gated channel activator in the rat formalin test

Background and objective Gabapentin, an anticonvulsant with analgesic effect, has been reported to be an activator of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels. In this study, we tested the effect of intrathecal ZD7288, an HCN channel inhibitor, and its interaction with intrathecal gabapentin in the rat formalin test. Methods Male Sprague–Dawley rats (250–300 g) with an intrathecal catheter were intraplantarly injected with formalin (5% formaldehyde, 50 μl) in the right hindpaw. Ten minutes before formalin injection, gabapentin (100 or 200 μg) was given intrathecally. ZD7288 (50 μg) was administered intrathecally 10 min before paw formalin injection or intrathecal gabapentin. The paw flinch numbers in 1 min were counted at the first minute and every 5 min for 1 h after formalin injection. Results Biphasic flinching responses were induced by formalin and monitored at 0–9 min (phase 1) and 10–60 min (phase 2) after formalin injection. Gabapentin (100 and 200 μg), given intrathecally 10 min before formalin injection, attenuated the flinching response during phase 2 of the formalin test. ZD7288 (50 μg), given intrathecally 10 min before formalin injection or intrathecal gabapentin injection, did not attenuate the formalin-induced flinching response or reverse gabapentin-induced analgesia. Conclusion Our data suggest that activation of spinal or dorsal root ganglion HCN channels or both is not involved in formalin-induced pain, and intrathecal gabapentin does not act as an HCN channel activator to achieve its antinociceptive effect in the formalin test.

Treatment of Spontaneous Intracranial Hypotension Secondary to Sacral Perineural Cysts by Caudal Epidural Blood Patch-a Case Report

Spontaneous intracranial hypotension (SIN), an uncommon reason of postural headache, is usually resulted from a spontaneous spinal cerebrospinal fluid (CSF) leak. However the mechanisms of the spontaneous CSF leak are unclear, and may be related to factors that cause dural sac weakness, such as sacral perineural cysts, the anatomical variations of the meninges in the lumbo-sacral region. In this report, we presented a female patient suffered from a postural headache. Sacral perineural cysts were noted according to her image study, and SIH was diagnosed. She was treated with the caudal epidural blood patch because of failed traditional treatments. We inserted a non-kinking catheter into the sacral epidural space under ultrasound-guidance and confirmed the location of catheter by the enhancement of contrast medium with fluoroscopy. After the treatment, the positional headache improved dramatically. In the discussion, we reviewed the clinical features, diagnosis, and managements of SIN and postural headache. We also discussed the possible pathophysiology of STH and mechanisms of the effect of epidural blood patch.

Ultrasound-Guided Pulsed Radiofrequency of Suprascapular Nerve for Chronic Shoulder Pain: A Case Report

Suprascapular nerve (SSN) blockade improves pain, range of motion, and disability in acute and chronic shoulder pain. Pain relief usually lasts several hours with local anesthetic. If steroids are added, the relief lasts several weeks. Since repetitive steroid exposure is associated with several hazards, alternative long-term therapies would be desirable. Pulsed radiofrequency (PRF) is a non-destructive, safe, and repeatable long-term pain control therapy. We report a case, wherein using ultrasound guidance and fluoroscopy and nerve stimulation confirmation, SSN PRF treatment was performed. It provided 9-10 months of pain relief and improvement in shoulder function, without deterioration in muscle strength.

Ultrasound-Guided Intercostal Nerve Block for Intractable Right Upper Quadrant Abdominal Pain: A Case Report

Abdominal visceral organ pathology is commonly the source of abdominal pain. However, some abdominal pain may originate from the abdominal wall muscles and be somatic in origin. Transversus Abdominis Plane (TAP) block is an effective block to offer analgesia for abdominal somatic pain. Intercostal nerve (ICN) blockade is also an useful diagnostic and therapeutic tool to manage pain covered by the distribution of thoracic nerves. Chronic abdominal wall pain can often be missed as a differential diagnosis for patients suffering with abdominal pain. We present a case of intractable right upper quadrant (RUQ) abdominal pain managed successfully with ultrasound-guided TAP and ICN block.

Refractory Trigeminal Neuralgia Successfully Treated with Gabapentin-A Case Report

Carbamazepine and its related anticonvulsants are the treatment of choice for trigeminal neuralgia for many years. But trigeminal neuralgia refractory to conventional anticonvulsant agents is still the main challenge to clinicians. We report a 42-year-old male who was a victim of trigeminal neuralgia for four years. Beside, he had undergone craniotomy and radiotherapy for right middle fossa meningioma five years ago. In general, his pain could be controlled by carbamazepine and baclofen. But the frequency and duration of the attack became severe despite the medical treatment. He described the pain sensation as sharp, stabbing and burning and it could be triggered by touch, shaving or chewing. Secondary trigeminal neuralgia was diagnosed because brain MRI examination revealed right trigeminal nerve root compression by a right parasellar area recurrent tumor. The neurologist had adjusted the medications to other traditional anticonvulsants but the pain was not resolved. The patient even tried not to eat or drink to avoid triggering the attack. Since the right internal carotid artery was involved and the risk of surgical treatment was high, radiotherapy was arranged. At the same time, we were consulted for neurolytic block. Considering the risk of the procedure, we suggested the use of gabapentin, a novel anticonvulsant and analgesic. Fortunately, the pain was relieved after one-week treatment of gabapentin and did not attack again during the 3 months follow-up. We present this case to offer another therapeutic option for trigeminal neuralgia that is refractory to traditional anticonvulsant drugs.