Sonographic diagnosis and evaluation in patients with superficial radial arteries.

BACKGROUND: The superficial radial artery (SRA) is a rare congenital anomaly in the forearm. However, it can be detected incidentally via trauma, intraoperative findings, angiography, or ultrasonography. In addition, intra-arterial infusion of intravenous medications and difficulties in radial artery catheterization may occur in cases of the SRA. METHODS: Between December 2016 and July 2020, anomalous branches of radial arteries were found incidentally in nine patients at the preoperative visit and identified during ultrasound-guided radial artery puncture in 21 patients when radial artery catheterization using the palpation method proved difficult. Ultrasound examinations were performed for diagnosis and evaluation of these 30 patients. RESULTS: All anomalous branches of the radial artery were SRAs; 11 (37%), 13 (43%), 6 (20%) were present on the right side, on the left side, and bilaterally, respectively. All SRAs ran close to the cephalic vein. The vascular diameters of the radial arteries were the smallest in the radial artery distal to the SRA bifurcation (followed by in the SRA) and the largest in the radial artery proximal to the bifurcation (p < .001). In two cases, color Doppler study revealed that both the blood flow and color Doppler signal of the SRA disappeared with compression of the radial artery proximal to the SRA bifurcation. CONCLUSIONS: Because the SRA runs very close to the cephalic vein, a tourniquet applied to the arm may easily lead to intravenous catheter misplacement into the SRA. In addition, the small radial artery distal to the SRA bifurcation causes difficulty in radial artery catheterization. Furthermore, SRA cases may have falsely normal Allen's test results. Therefore, the authors recommend that the SRA must be identified before vascular puncture for safe vascular catheterization in the forearm.

Comparison of three obturator nerve block techniques for injectate spread into the obturator canal: a randomized controlled trial.

PURPOSE: The obturator nerve branches into the obturator canal; therefore, local anesthetic spread into the obturator canal predicts the success of the obturator nerve block (ONB). We compared three ONB techniques for the spread of local anesthetic mixed with contrast medium into the obturator canal. METHODS: We performed the ONB using the classical pubic approach (PA), inguinal approach (IA), or ultrasound-guided methodologic approach (UMA) in 143 patients undergoing transurethral resection of bladder tumors. The obturator nerve course and branching patterns of the UMA group were examined using ultrasound imaging. After injecting a local anesthetic mixed with a contrast medium, we evaluated its spread into the obturator canal using fluoroscopic imaging. P < 0.05 indicated statistical significance. RESULTS: Success rate of obturator canal enhancement was the greatest in the UMA group (84%; P < 0.001); the PA (42.6%; 20/47 patients) and IA (47.8%; 22/46 patients) groups did not differ significantly (P = 1.000). Both branches of the obturator nerve passed above the superior margin of the external obturator muscle (EOM), and the obturator canal was enhanced in 13 of 50 (26%) patients in the UMA group. The posterior branch of the obturator nerve passed between the superior and main fasciculi of the EOM in 37 of 50 patients (74%) in the UMA group; the obturator canal was enhanced in 29 of these 37 patients (78%). CONCLUSION: Local anesthetic spread into the obturator canal using the UMA was superior to that using the PA and IA. Both branches of the obturator nerve could be blocked using the UMA.

Ultrasound-guided central venous tip confirmation via right external jugular vein using a right supraclavicular fossa view.

INTRODUCTION:: Ultrasound-guided central venous catheter tip confirmation has a potential to precisely locate the central venous catheter, preventing its misplacement, using real-time guidance. This observational study sought to determine the accuracy of central venous catheter tip positioning via the external jugular vein via a supraclavicular fossa view under ultrasound guidance. METHODS:: In total, 77 patients scheduled for central venous catheter insertion via the right external jugular vein were enrolled. The depth of central venous catheter insertion was determined by advancing the tip of the guidewire to the junction of the superior vena cava and right pulmonary artery, using a right supraclavicular fossa view ultrasound method. We determined the reference insertion depth to the carina using a postoperative chest x-ray photograph method. We then compared insertion depths obtained by the ultrasound and x-ray photograph methods and body-height formula. RESULTS:: In total, 62 patients were able to advance the guidewire and underwent ultrasound-guided central venous catheter insertion. In four patients, we corrected for misplaced guidewires. According to Bland-Altman plots, the insertion depth was 0.88 cm shorter for the ultrasound method (95% limits of agreement, -1.66 to 3.41 cm) and 0.90 cm shorter for the formulaic method (95% limits of agreement, -2.77 to 4.56 cm), compared with the x-ray photograph method. The x-ray photograph method had significantly positive correlations with the ultrasound (r = 0.73) and formulaic methods (r = 0.27). CONCLUSION:: A right supraclavicular fossa view improves the accuracy of central venous catheter tip positioning and prevents central venous catheter misplacement via the right external jugular vein.

Lateral deviation of four types of epidural catheters from the lumbar epidural space into the intervertebral foramen.

BACKGROUND: During epidural anesthesia, the catheter tip occasionally deviates from the epidural space into the intervertebral foramen, resulting in inadequate anesthesia. METHODS: During postoperative plain radiography, iohexol was injected via the epidural catheter to determine its position and to observe the spread of the material. After exclusion of seven patients with catheters that migrated into the subcutaneous area and 25 patients with no evidence of the contrast medium, 415 patients were evaluated. We retrospectively compared patients to determine whether the incidence of deviation into the intervertebral foramen differed between four types of epidural catheters. We also investigated the load applied to the catheter tip using a Shimadzu Autograph AG-X-500 N-111 universal testing machine. RESULTS: Deviation of the epidural catheter into the intervertebral foramen was observed in eight and 33 patients in the Hakko and Perifix Soft tip catheter groups, respectively. The incidence of deviation was higher in the Perifix Soft tip catheter group, and lower in the FlexTip Plus and Perifix FX catheter groups. A rapid increase was observed in the force exerted on the tips of the Hakko and Perifix Soft tip catheters, while the force transmitted to the tips of the FlexTip Plus and Perifix FX catheters gradually increased and then reached a plateau at a low level. CONCLUSIONS: The incidence of deviation was significantly lower with spiral-type catheters than with other types of catheters. This might be attributable to the gradual transmission of a lower level of force to the tip in spiral-type catheters.

Ultrasound visibility of regional anesthesia catheters: an in vitro study.

BACKGROUND: Ultrasound subjective visibility of in-plane needles is correlated with the intensity difference between the needle surface and the background. Regional anesthesia catheters are difficult to visualize by an ultrasound. In the present study, we investigated the ultrasound visibility of the catheters. METHODS: Six catheters were placed at 0° and 30° relative to and at a depth of 1 cm below the pork phantom surface. Ultrasound images of in-plane catheters were evaluated, subjectively and objectively. Outer and inner objective visibilities were defined as the difference in the mean pixel intensity between the catheter surface and adjacent background, and between the surface and the center of the catheter, respectively. Evaluations were made based on the portion of the catheters. A P value < 0.05 was considered significant. RESULTS: Subjective visibility was more strongly correlated with the inner objective visibility than with the outer objective visibility at both angles. Metallic 19-gauge catheters were more subjectively visible than the non-metallic 20-gauge catheters at 30° degrees (P < 0.01). Subjective, and outer and inner objective visibility were significantly lower at 30° than at 0° (P < 0.01, P < 0.01, P = 0.02). Perifix ONE at 0° and Perifix FX at 30° were the most visible catheters (P < 0.01 for both). CONCLUSIONS: Subjective visibility of catheters can not be evaluated in the same manner as that of the needles. For the best possible visualization, we recommend selecting a catheter with a structure that enhances the dark at the center of catheter, rather than basing the catheter selection on the bore size.

New anthranilic acid derivative, EAntS-GS, attenuates Freund's complete adjuvant-induced acute pain in rats.

BACKGROUND: Acute and chronic pain commonly accompany various clinical conditions such as contusion, fracture, osteoarthritis, peripheral neuropathy, and postherpetic neuralgia. Recent studies have found that antioxidative drugs can have analgesic effects. The present study tested the hypothesis that a new anthranilic acid derivative, EAntS-GS, exerts antinociceptive effects on inflammatory pain in a rat model. METHODS: We induced subacute pain with a plantar injection of Freund's complete adjuvant (FCA) in Sprague-Dawley rats. EAntS-GS (1 mg/kg subcutaneous injection or 1% application) was administered every 12 h beginning 24 h after FCA administration, and the plantar test was used to determine its effect on pain. Levels of myeloperoxidase, inducible nitric oxide synthase (iNOS), and protease activated receptor 2 (PAR2) were measured to elucidate the mechanism of action of EAntS-GS. RESULTS: EAntS-GS significantly reduced FCA-induced pain and myeloperoxidase, iNOS, and PAR2 levels. Our findings suggest that the new anthranilic acid derivative, EAntS-GS, exerts antinociceptive effects, and that the mechanism involves iNOS and PAR2. CONCLUSION: We conclude that EAntS-GS should be considered a new therapeutic tool to treat acute and chronic pain.

The antinociceptive effects of estradiol on adjuvant-induced hyperalgesia in rats involve activation of adrenergic and serotonergic systems.

PURPOSE: Estradiol is a female hormone required for maintaining pregnancy and developing follicles in the ovary. Estradiol has been shown to perform a variety of physiological activities, including pain reduction. In this study, we tested the hypothesis that estradiol exerts antinociceptive effects in a rat model of inflammatory hyperalgesia. METHODS: We established a subacute hyperalgesia model using plantar injection of Freund's complete adjuvant (FCA) in Sprague-Dawley rats. We administered estradiol every 24 h, beginning 12 h after FCA administration, and used the plantar test to determine its effect on hyperalgesia. To determine the mechanism of action of estradiol, we evaluated the role of the opioid antinociceptive system using naloxone and the role of the descending pain inhibitory system using the α-2-receptor antagonist yohimbine and the serotonin receptor antagonist methysergide. RESULTS: Administration of FCA induced hyperalgesia, which was significantly reduced by estradiol treatment compared to controls. Moreover, this effect was not antagonized by naloxone, but was attenuated by α-2-receptor and serotonin-receptor antagonists. CONCLUSION: Estradiol is known to perform a variety of physiological functions. Our findings suggest that one such function is antinociception via an interaction with α-2 receptors and serotonin receptors.

Effective control of paroxysmal tachycardia with landiolol hydrochloride during cesarean section in a patient with hypertrophic obstructive cardiomyopathy.

Hypertrophic obstructive cardiomyopathy (HOCM) involves marked hypertrophy of cardiac muscle, resulting in myocardial ischemia and arrhythmia because of left ventricular diastolic dysfunction. In perioperative management of HOCM, hemodynamic stabilization is required, by prevention of arrhythmia and tachycardia and maintenance of preload and afterload. Here, we describe anesthesia management during cesarean section in a patient complicated by HOCM. The patient was a 27-year-old woman who underwent elective cesarean section scheduled at 36 weeks of pregnancy given her history of HOCM. She was managed with spinal anesthesia with monitoring of invasive blood pressure and arterial pressure cardiac output. Administration of landiolol hydrochloride was initiated, because of paroxysmal tachycardia after delivery. Approximately 5 min after initiation of administration, her heart rate decreased gradually and blood pressure rose. Circulatory dynamics stabilized and landiolol was discontinued 3 h after she was admitted to the intensive care unit. Her circulatory dynamics remained stable after discontinuation of landiolol, and she was moved to a general ward on the following day. She was discharged on postoperative day 14, with her child.

Use of imaging agent to determine postoperative indwelling epidural catheter position.

BACKGROUND: Epidural anesthesia is widely used to provide pain relief, whether for surgical anesthesia, postoperative analgesia, treatment of chronic pain, or to facilitate painless childbirth. In many cases, however, the epidural catheter is inserted blindly and the indwelling catheter position is almost always uncertain. METHODS: In this study, the loss-of-resistance technique was used and an imaging agent was injected through the indwelling epidural anesthesia catheter to confirm the position of its tip and examine the migration rate. Study subjects were patients scheduled to undergo surgery using general anesthesia combined with epidural anesthesia. Placement of the epidural catheter was confirmed postoperatively by injection of an imaging agent and X-ray imaging. RESULTS: The indwelling epidural catheter was placed between upper thoracic vertebrae (n = 83; incorrect placement, n = 5), lower thoracic vertebrae (n = 123; incorrect placement, n = 5), and lower thoracic vertebra-lumbar vertebra (n = 46; incorrect placement, n = 7). In this study, a relatively high frequency of incorrectly placed epidural catheters using the loss-of-resistance technique was observed, and it was found that incorrect catheter placement resulted in inadequate analgesia during surgery. CONCLUSIONS: Although the loss-of-resistance technique is easy and convenient as a method for epidural catheter placement, it frequently results in inadequate placement of epidural catheters. Care should be taken when performing this procedure.

Activation of sensory neurons reduces ischemia/reperfusion-induced acute renal injury in rats.

BACKGROUND: Prostaglandin I2 (PGI2) produced by endothelial cells improves ischemia/reperfusion-induced acute renal injury by inhibiting leukocyte activation in rats. However, the underlying mechanism(s) of increased PGI2 production is not fully understood. Activation of sensory neurons increases endothelial PGI2 production by releasing calcitonin gene-related peptide (CGRP) in rats with hepatic ischemia or reperfusion. We examined here whether activation of sensory neurons increases PGI2 endothelial production, thereby reducing ischemia/reperfusion-induced acute renal injury. METHODS: Anesthetized rats were subjected to 45 min of renal ischemia/reperfusion. Rats were pretreated with CGRP, capsazepine (a vanilloid receptor-1 antagonist), CGRP(8-37) (a CGRP receptor antagonist), or indomethacin (a cyclooxygenase inhibitor), or subjected to denervation of primary sensory nerves before ischemia/reperfusion. RESULTS: Renal tissue levels of CGRP and 6-keto-prostaglandin F1alpha, a stable metabolite of PGI2, increased after renal ischemia/reperfusion, peaking at 1 h after reperfusion. Overexpression of CGRP was also noted at 1 h after reperfusion. Increases in renal tissue levels of 6-keto-prostaglandin F1alpha at 1 h after reperfusion were significantly inhibited by pretreatment with capsazepine, CGRP(8-37), and indomethacin. Pretreatment with capsazepine, CGRP(8-37), indomethacin, and denervation of primary sensory nerves significantly increased blood urea nitrogen and serum creatinine levels, renal vascular permeability, renal tissue levels of myeloperoxidase activity, cytokine-induced neutrophil chemoattractant, and tumor necrosis factor-alpha, and decreased renal tissue blood flow. However, pretreatment with CGRP significantly improved these changes. CONCLUSIONS: Our results suggest activation of sensory neurons in the pathologic process of ischemia/reperfusion-induced acute renal injury. Such activation reduces acute renal injury by attenuating inflammatory responses through enhanced endothelial PGI2 production.