Application of nasal bi-level positive airway pressure to respiratory support during combined epidural-propofol anesthesia

STUDY OBJECTIVE: To examine whether nasal bi-level positive airway pressure (BiPAP) can be used as an airway during combined epidural-propofol anesthesia. DESIGN: Prospective, consecutive case series study. SETTING: Operating room at a general hospital. PATIENTS: 213 ASA physical status I and II adult patients undergoing lower extremity or lower abdominal gynecology surgery. INTERVENTIONS: After epidural anesthesia, propofol was infused at 20 mg/kg/hr (P20) for 4 to 5 minutes followed by 5 mg/kg/hr (P5), and nasal continuous positive airway pressure (CPAP) 8 cm H(2)O and BiPAP 14/8 cm H(2)O was applied. In clinical situations, BiPAP with respiratory rate (RR) 10 breaths/min was applied. Furthermore, tidal volume (V(T)) during anesthesia, the effect of changing pressure support levels, and evaluation of pressure-controlled ventilation without spontaneous breathing were examined. MEASUREMENTS AND MAIN RESULTS: CPAP resulted in a high RR, marked increased PaCO(2), and slightly decreased PaO(2), whereas BiPAP showed no change or a slightly decreased RR, slightly increased PaCO(2), and no change in PaO(2) or a great increase in PaO(2) with oxygen delivery. In clinical applications, similar results were found and anesthetic conditions were sufficient. Tidal volume increased after induction and maintained increased values under BiPAP 14/8 cm H(2)O. Of V(T) at 2, 6, or 10 cm H(2)O of pressure support levels, the 6 cm H(2)O was appropriate. Vecuronium injection showed a slight decrease and then increase in V(T) and PaCO(2), but the values were within normal (safe) limits. Respiration after rapid and high-dose infusion of propofol showed a markedly decreased RR, but the V(T) was maintained, and PaCO(2) and PaO(2) were at safe values. Rapid induction with 2.0 mg/kg propofol followed by P5 showed satisfactory results, in all but the obese patients.CONCLUSIONS: BiPAP 14/8 cm H(2)0 with RR at 10 breaths/min during combined epidural-propofol anesthesia can be used to provide ventilatory support in lower extremity or lower abdominal gynecology surgery.     

Correlation between diffusion-tensor magnetic resonance imaging and motor-evoked potential in chronic severe diffuse axonal injury

We conducted a study to evaluate the degree of corticospinal tract (CST) dysfunction associated with diffuse axonal injury (DAI) through analyses of both diffusion-tensor magnetic resonance imaging (DTMRI) and motor-evoked potential (MEP). Using DTMRI and MEP with transcranial magnetic stimulation, we evaluated 138 instances of CST in 52 patients with severe chronic DAI and compared them with the findings in 17 normal volunteers. We determined values of fractional anisotropy (FA) on FA maps obtained with DTMRI of six regions of interest (ROIs) in the CST, consisting of the semioval center, coronal radiation, posterior limb of internal capsule, midbrain, pons and medulla oblongata. The lowest value of %FA for each of the six ROIs in each CST was defined as the minimum %FA, and the lowest magnetic stimulation strength that produced MEP was defined as the minimum threshold for MEP. The mean minimum %FA for CSTs in which MEP could not be obtained even with maximum magnetic stimulation (the MEP- group) was significantly lower than that of CSTs in which MEP could be obtained (the MEP+ group). ROIs with the lowest %FA value were the midbrain in the MEP+ group and the medulla oblongata in the MEP- group. In the MEP+ group, a serial decrease in the minimum %FA value significantly correlated with a serial increase in minimum threshold for MEP. These results show that in patients with chronic DAI, physiological motor dysfunction as revealed by MEP correlates significantly with morphological damage to the CST as detected by DTMRI. This strongly suggests that DTMRI can be a valuable tool for evaluating aberrant motor function and for estimating its severity in DAI.     

Emergency craniotomy for intraparenchymal massive hematoma after embolization of supratentorial arteriovenous malformations

OBJECTIVE: We sought to evaluate the efficacy of emergency craniotomy for patients with massive hematoma secondary to endovascular embolization of supratentorial arteriovenous malformations (AVMs) and to investigate relevant factors affecting outcome. METHODS: Within the past 15 years, 605 patients with intracranial AVMs have undergone 1066 endovascular embolizations at our institution. Of these, 24 patients experienced intracranial hemorrhage during or after the procedure. Fourteen patients were demonstrated to have massive intraparenchymal hematomas and deteriorated to a comatose state (Glasgow Come Scale score < or =6). Twelve patients underwent craniotomy within 170 minutes of being diagnosed with intraparenchymal hemorrhage. The surgical procedures performed were hematoma evacuation with total (6 patients) or partial (2 patients) resection of the AVM or hematoma evacuation only (4 patients). The clinical records of these 12 patients were analyzed retrospectively. RESULTS: Nine patients recovered to a favorable condition (good recovery, four patients; moderately disabled, five patients), one patient remained in a persistent vegetative state, and two patients died. The interval between hemorrhage and emergency craniotomy was significantly shorter in patients with favorable outcomes than in those with poor clinical outcomes. Advanced age and a larger volume of intraoperative blood loss were the factors relevant to poor outcome. Temporal lobe location of the AVM and incomplete embolization tended to correlate to poor clinical outcome, but this correlation was not statistically significant. The sizes of the AVM and the hematoma did not correlate to patient outcome. There was no difference in outcomes with regard to the surgical procedure performed. CONCLUSION: In patients with massive postembolization hematomas, emergency craniotomy should be performed as soon as possible to achieve a favorable outcome. Cooperation among interventional neuroradiologists, intensive care physicians, and neurosurgeons is essential to manage AVM patients with critical postembolization hemorrhage. There is no need to persist in performing simultaneous total resection of the AVM at the emergency craniotomy.     

Shoulder and elbow pain in elementary school baseball players: The results from a nation-wide survey in Japan

Background

Despite recommendations on how to prevent baseball injuries in youths by the Japanese Society of Clinical Sports Medicine, shoulder and elbow pain still frequently occurs in young baseball players. We conducted a questionnaire survey among baseball players at elementary schools across the country to understand the practice conditions of players, examining the risk factors of shoulder and elbow pain in baseball players.

Morphologic Features of Carotid Plaque Rupture Assessed by Optical Coherence Tomography

BACKGROUND AND PURPOSE:Rupture of the plaque fibrous cap and subsequent thrombosis are the major causes of stroke. This study evaluated morphologic features of plaque rupture in the carotid artery by using optical coherence tomography in vivo.MATERIALS AND METHODS:Thirty-six carotid plaques with high-grade stenosis were prospectively imaged by optical coherence tomography. “Plaque rupture” was defined as a plaque containing a cavity that had overlying residual fibrous caps. The fibrous cap thickness was measured at its thinnest part for both ruptured and nonruptured plaques. The distance between the minimum fibrous cap thickness site and the bifurcation point was also measured. Optical coherence tomography identified 24 ruptured and 12 nonruptured plaques.RESULTS:Multiple ruptures were observed in 9 (38%) patients: Six patients had 2 ruptures in the same plaque, 2 patients had 3 ruptures in the same plaque, and 1 patient had 5 ruptures in the same plaque. Most (84%) of the fibrous cap disruptions were identified at the plaque shoulder and near the bifurcation point (within a 4.2-mm distance). The median thinnest cap thickness was 80 μm (interquartile range, 70–100 μm), and 95% of ruptured plaques had fibrous caps of <130 μm. Receiver operating characteristic analysis revealed that a fibrous cap thickness of <130 μm was the critical threshold value for plaque rupture in the carotid artery.CONCLUSIONS:Plaque rupture was common in high-grade stenosis and was located at the shoulder of the carotid plaque close to the bifurcation. A cap thickness of <130 μm was the threshold for plaque rupture in the carotid artery.

Rupture of the fibrous cap and subsequent thrombosis are the major causes of cardiovascular events such as heart attack and stroke.^1–3 In a previous study of sudden coronary death, a fibrous cap thickness of 65 μm was chosen as a criterion of instability because for a cap to rupture, the average cap thickness was 23 ± 19 μm; 95% of caps measured <65 μm within a limit of only 2 SDs.¹ Therefore, the fibrous cap thickness of <65 μm is now widely accepted as the definition of in vivo coronary vulnerable plaque that is prone to rupture. Disruption of the fibrous cap is frequently observed in symptomatic carotid plaques^4,5 and is strongly associated with an ulceration appearance on angiography,⁶ which is considered an independent predictor of stroke on long-term follow-up in patients with symptomatic severe carotid stenosis.⁷ Redgrave et al⁸ examined the cross-sections of plaques with high-grade carotid stenosis and found that the optimum fibrous cap thickness for discriminating ruptured and nonruptured plaques was 200 μm; thus, it appears that there is no clear threshold for classifying plaques that are prone to rupture in vivo.Intravascular sonography, which is a widely used imaging method in the field of carotid artery intervention, has an axial resolution of 100–200 μm and a lateral resolution of 250 μm.⁹ Although it can visualize deep structures, intravascular sonography is not a suitable imaging technique for the detection of thin fibrous caps because its resolution is too low. Optical coherence tomography (OCT) has been introduced recently as a high-resolution imaging method.^10,11 The typical OCT image has an axial resolution of 10 μm, approximately 10 times higher than that of any other clinically available diagnostic imaging technique, such as intravascular sonography. OCT provides an accurate representation of the thickness of the fibrous cap that could not be measured by other imaging modalities.¹² In the present study, we evaluated the morphologic features of ruptured plaques in the carotid artery by using OCT.     

ATP1A3 variants and slowly progressive cerebellar ataxia without paroxysmal or episodic symptoms in children

A heterogeneous spectrum of clinical manifestations caused by mutations in ATP1A3 have been previously described. Here we report two cases of infantile‐onset cerebellar ataxia, due to two different ATP1A3 variants. Both patients showed slowly progressive cerebellar ataxia without paroxysmal or episodic symptoms. Brain magnetic resonance imaging revealed mild cerebellar cortical atrophy in both patients. Whole exome sequencing revealed a de novo heterozygous variant in ATP1A3 in both patients. One patient had the c.460A>G (p.Met154Val) variant, while the other carried the c.1050C>A (p.Asp350Lys) variant. This phenotype was characterized by a slowly progressive cerebellar ataxia since the infantile period, which has not been previously described in association with ATP1A3 variants or in ATP1A3‐related clinical conditions. Our report contributes to extend the phenotypic spectrum of ATP1A3 mutations, showing paediatric slowly progressive cerebellar ataxia with mild cerebellar atrophy alone as an additional clinical presentation of ATP1A3‐related neurological disorders.     

Development of invasive adenocarcinoma in a long-standing diverted ileal J-pouch for ulcerative colitis

We report a case of a 50-year-old male with ulcerative colitis who developed well-differentiated adenocarcinoma in the ileal J-pouch, which had been defunctioning for 18 years. The extension of the carcinoma in the pouch suggested that it had recently appeared in the pouch. Monitoring by endoscopic examination and biopsy or pouch excision seems to be an appropriate action if a pouch is out of the fecal stream.     

The RNA-binding protein xCIRP2 is involved in apoptotic tail regression during metamorphosis in Xenopus laevis tadpoles

Frog metamorphosis induced by thyroid hormone (TH) involves not only cell proliferation and differentiation in reconstituted organs such as limbs, but also apoptotic cell death in degenerated organs such as tails. However, the molecular mechanisms directing the TH-dependent cell fate determination remain unclear. We have previously identified from newts an RNA-binding protein (nRBP) acting as the regulator governing survival and death in germ cells during spermatogenesis. To investigate the molecular events leading the tail resorption during metamorphosis, we analyzed the expression, the functional role in apoptosis, and the regulation of xCIRP2, a frog homolog of nRBP, in tails of Xenopus laevis tadpoles. At the prometamorphic stage, xCIRP2 protein is expressed in fibroblast, epidermal, nerve, and muscular cells and localized in their cytoplasm. When spontaneous metamorphosis progressed, the level of xCIRP2 mRNA remained unchanged but the amount of the protein decreased. In organ cultures of tails at the prometamorphic stage, xCIRP2 protein decreased before their lengths shortened during TH-dependent metamorphosis. The inhibition of calpain or proteasome attenuated the TH-induced decrease of xCIRP2 protein in tails, impairing their regression. These results suggest that xCIRP2 protein is downregulated through calpain- and proteasome-mediated proteolysis in response to TH at the onset of metamorphosis, inducing apoptosis in tails and thereby degenerating them.     

Chronic Hyponatremia Causes Neurologic and Psychologic Impairments

Hyponatremia is the most common clinical electrolyte disorder. Once thought to be asymptomatic in response to adaptation by the brain, recent evidence suggests that chronic hyponatremia may be linked to attention deficits, gait disturbances, risk of falls, and cognitive impairments. Such neurologic defects are associated with a reduction in quality of life and may be a significant cause of mortality. However, because underlying diseases such as adrenal insufficiency, heart failure, liver cirrhosis, and cancer may also affect brain function, the contribution of hyponatremia alone to neurologic manifestations and the underlying mechanisms remain unclear. Using a syndrome of inappropriate secretion of antidiuretic hormone rat model, we show here that sustained reduction of serum sodium ion concentration induced gait disturbances; facilitated the extinction of a contextual fear memory; caused cognitive impairment in a novel object recognition test; and impaired long-term potentiation at hippocampal CA3–CA1 synapses. In vivo microdialysis revealed an elevated extracellular glutamate concentration in the hippocampus of chronically hyponatremic rats. A sustained low extracellular sodium ion concentration also decreased glutamate uptake by primary astrocyte cultures, suggesting an underlying mechanism of impaired long-term potentiation. Furthermore, gait and memory performances of corrected hyponatremic rats were equivalent to those of control rats. Thus, these results suggest chronic hyponatremia in humans may cause gait disturbance and cognitive impairment, but these abnormalities are reversible and careful correction of this condition may improve quality of life and reduce mortality.