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Background: Hand fractures are among the most common injuries presenting in pediatric emergency departments (EDs) with incidence reported as high as 624 hand fractures per 100,000 person-years. If gone untreated, these injuries can lead to pain, loss of function, and psychological trauma. The purpose of this study was to identify risk factors and characterize pediatric hand fractures over a 5-year period., Methods: The National Electronic Injury Surveillance System (NEISS) was queried for all hand fractures in patients aged 1 to 19 years presenting to US EDs between 2016 and 2020. Incidence was calculated using US census data. Cases were retrospectively analyzed using age, location of the injury, sex, coronavirus disease-2019 (COVID-19) era, and etiology of injury. Bivariate logistic regression was used where appropriate., Results: A total of 21,031 pediatric hand fractures were identified, representing an estimated 565,833 pediatric hand fractures presenting to EDs between 2016 and 2020. The mean incidence of pediatric hand fractures was 138.3 fractures for 100,000 person-years [95% confidence interval (CI): 136.2-140.4], with a 39.2% decrease in incidence occurring between 2019 and 2020. It was found that 42.2% of the fractures were in patients aged 10 to 14. The incidence of hand fractures for males and females was 97.9 (95% CI: 96.2-99.7) and 40.4 (95% CI: 39.2-41.5), respectively, with the male rate peaking at age 14 and the female rate peaking at age 12. Age, sex, location of the injury, and injury during the COVID-19 pandemic were demonstrated to influence the frequency and etiology of the fracture., Conclusion: This study determined the incidence of pediatric hand fractures presenting to EDs across the United States. In addition, it identified risk factors for common hand fracture etiologies (sports-related, falling, crush, punching) and demonstrated the change in rates of different etiologies of pediatric hand fractures that presented to US EDs during the COVID-19 pandemic., Level of Evidence: Level III-retrospective comparative study., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Previous studies have demonstrated that the metastability threshold of aqueous oxygen (AO) is inversely dependent on the internal diameter of capillary tubes used to deliver it into blood. The hypothesis was tested herein that significantly higher thresholds are attainable with capillaries having markedly smaller dimensions (submicron) than those previously studied. Water was equilibrated with oxygen over a 0.3- to 0.7-k bar range. Inert gases (argon, helium) facilitated studies at pressures to 2.5 k bar. An argon-ion laser was used to visualize fluorescein in the liquid effluent from silica capillaries that were tapered at the distal end to a submicron internal diameter (0.5 +/- 0.3 microns). During infusion of the fluorescent effluent into host water at 21 degrees C and atmospheric pressure, integrity of the effluent and lack of microbubbles were monitored by videomicroscopy. No microbubbles were noted at AO concentrations ranging from 7.5 to 12.8 ml O2/g (0.34 to 0.68 k bar, respectively) or in the aqueous argon effluent at concentrations to 14 ml Ar/g (0.75 k bar). For aqueous helium, effluent nucleation was not observed at a mean concentration of 13 +/- 3 ml He/g (2.0 +/- 0.5 k bar), with an upper value of 15.2 ml He/g (2.4 k bar). The data represent the highest values of the tensile strength of water ever observed and approximate its theoretical homogeneous nucleation limit. Thus, remarkably high metastable concentrations of AO and other gases are attainable with the use of submicron capillaries.

Uncorrected microvascular ischemia may contribute to left ventricular impairment during reperfusion after prolonged coronary artery occlusion. Attenuation of such ischemia in microvessels with impaired erythrocyte flow may require delivery of oxygen at high levels in plasma. Intraarterial infusion of aqueous oxygen (AO) can be used in a site specific manner to achieve hyperoxemic levels of oxygenation in the perfusate. With this new approach, the hypothesis was tested that reperfusion microvascular ischemia can be attenuated. After a 90 min coronary balloon occlusion in a canine model, AO hyperoxemic intracoronary perfusion was performed for 90 min after a 30 min period of autoreperfusion. Control groups consisted of normoxemic reperfusion, both passive (autoreperfusion) and active (roller pump). A significant improvement in left ventricular ejection fraction (p < 0.05) at 2 hr of reperfusion was noted only in the AO hyperoxemia group (17 +/- 6% by two dimensional echo), without a significant reduction in the improvement 1 hr after termination of treatment. During AO hyperoxemic perfusion, ECG ST segment isoelectric deviation normalized, and frequency of ventricular premature contractions was significantly reduced, in contrast to the autoreperfusion control group (p < 0.05). Microvascular blood flow, measured as the ischemic/normal left ventricular segment ratio by radiolabeled microspheres immediately after AO hyperoxemic perfusion, was double the value of the autoreperfusion control group at 2 hr of reperfusion (p < 0.05). We conclude that reperfusion microvascular ischemia is attenuated by intracoronary AO hyperoxemic perfusion and acutely improves left ventricular function in this model.

Background: High levels of hyperoxemia may have utility in the treatment of regional tissue ischemia, but current methods for its implementation are impractical. A catheter-based method for infusion of O2, dissolved in a crystalloid solution at extremely high concentrations, ie, 1 to 3 mL O2/g (aqueous oxygen [AO]), into blood without bubble nucleation was recently developed for the potential hyperoxemic treatment of regional tissue ischemia., Methods and Results: To test the hypotheses that hypoxemia is correctable and that hyperoxemia can be produced locally by AO infusion, normal saline equilibrated with O2 at 3 MPa (30 bar; 1 mL O2/g) was delivered into arterial blood in two different animal models. In 15 New Zealand White rabbits with systemic hypoxemia, AO was infused into the midabdominal aorta at 1 g/min. Mean distal arterial PO2 increased to 236+/-113 and 593+/-114 mm Hg on 1-hour periods of air and O2 breathing, respectively, from a baseline of 70+/-10 mm Hg (P<.01). In contrast, infusion of ordinary normal saline in a control group (n=7) had no effect on arterial PO2. No differences between groups (P>.05) in temporal changes in blood counts and chemistries were identified. In 10 dogs, low coronary blood flow in the circumflex artery was delivered with a roller pump through the central channel of an occluding balloon catheter. Hypoxemic, normoxemic, and AO-induced hyperoxemic blood perfusates (mean PO2, 52+/-4, 111+/-22, and 504+/-72 mm Hg, respectively) were infused for 3-minute periods in a randomized sequence. Short-axis two-dimensional echocardiography demonstrated a significant decrease (P<.05) in left ventricular ejection fraction compared with baseline physiological values with low-flow hypoxemic and normoxemic perfusion but not with low-flow hyperoxemic perfusion., Conclusions: Intra-arterial AO infusion was effective in these models for regional correction of hypoxemia and production of hyperoxemia.

Background: Radiofrequency catheter ablation of left-sided accessory pathways is becoming the first line of therapy for patients with symptomatic Wolff-Parkinson-White syndrome. Nevertheless, alternative ablation techniques merit development, at least as supplementary modalities for cases in which conventional ablation approaches may prove unsuccessful. We recently reported the short-term results with transcatheter laser balloon ablation from the coronary sinus in a canine model, proving that the procedure is feasible for the potential ablation of left-sided accessory pathways. We now report the effects of percutaneous transcatheter laser balloon ablation in a chronic canine model., Methods and Results: Twenty adult mongrel dogs were studied. After baseline coronary arteriography, left ventriculography, and coronary sinus angiography were obtained, 15 dogs received two or three consecutive laser doses from the coronary sinus of 30-40 W for 15-30 seconds, for a total cumulative energy of 1,200-2,400 J. The five remaining animals underwent a procedure consisting of balloon sham inflation without laser exposure and served as controls. After a mean follow-up of 6 weeks, the angiographic procedures were repeated, and the animals were killed. The mean extent of the fibrotic lesion was 15 mm long, 6 mm wide, and 4.5 mm deep and involved the coronary sinus wall, atrium, and, frequently, the summit of the posterior left ventricular wall. Six animals (four in the study group and two in the control group) showed asymptomatic narrowing of the coronary sinus lumen but always with total angiographic reconstitution due to extensive collateral circulation. The circumflex artery and mitral valve were intact angiographically and histologically in all animals., Conclusions: Percutaneous transcatheter laser balloon ablation via the coronary sinus produces a lesion that may be anatomically well suited for left-sided accessory pathway ablation. Although coronary sinus narrowing may occur, adverse physiological effects are unlikely due to the development of extensive collateral circulation. Systematic clinical studies of this new approach to catheter ablation appear warranted.

To determine whether anesthesiologists can manually detect significant changes in pulmonary compliance in neonates using an "educated hand," the authors tested whether clinicians could detect clamping of an endotracheal tube connecting a neonatal lung model to one of three anesthesia breathing circuits. The test lungs corresponded to the lung of a full-term neonate (large lung) or a premature neonate (small lung), and the circuits were a disposable Mapleson D and a disposable pediatric circle system with and without a humidifier. Clinicians having four levels of expertise (inexperienced anesthesia residents, experienced anesthesia residents, faculty not specializing in pediatric anesthesia, and specialized pediatric anesthesia faculty) were permitted to choose fresh gas flows, ventilatory pattern, and rate. After an acclimation period, the endotracheal tube connecting the test lung to the circuit was occluded once for 30 s. Clinicians were credited with a successful detection if they reported the occlusion within 15 s and had fewer than one false positive per minute. With the large lung model, only 4 of 24 clinicians detected occlusion with the Mapleson D circuit; similar results were obtained with the other circuits. With the small lung model, the only successful detection occurred with the Mapleson D circuit. Success at detecting occlusion was similarly low for clinicians with different levels of expertise. The authors conclude that the commonly held belief that the "educated hand" permits clinicians to detect subtle changes in pulmonary compliance in neonates during anesthesia (necessitating manual rather than mechanical ventilation) is not true.

Abrupt coronary occlusion and long-term restenosis continue to be the major problems associated with percutaneous transluminal coronary angioplasty (PTCA). Laser balloon angioplasty (LBA) is a technique designed to potentially alleviate these problems by sealing arterial dissections, smoothing the luminal surfaces, dehydrating thrombi, and reducing the elastic properties that tend to recoil the stretched artery to its original state. During LBA, laser energy is delivered circumferentially by a 100-microns optical fiber that terminates in a central diffusing tip within an angioplasty balloon. LBA is performed for 20 seconds during the final inflation of the angioplasty balloon. Achieved with decremental ramped laser dosimetry, Nd:YAG laser energy has been shown to be effective in welding experimental arterial dissections over a therapeutic temperature range of 95 degrees-120 degrees C. LBA treatment of rabbit iliac arteries has been superior to balloon angioplasty in inhibiting elastic recoil and causing acute and long-term luminal increment. LBA has also been effective for sealing acute dissections in atherosclerotic rabbit iliac arteries. Additionally, in a canine model, safety in the coronary circulation has been shown, that is, even at 1 month after LBA, angiography demonstrated a cast of the LBA balloon without luminal compromise. Since March 1988, more than 250 patients with symptomatic coronary artery disease have been treated with LBA with nearly uniform clinical success, including frequent reversal of abrupt closure. LBA seems to be a safe modality that may decrease the need for emergency operative procedures and late coronary revascularization after PTCA.

Drugs that localize in valvular vegetations may be useful in the diagnosis and treatment of infective endocarditis. We therefore tested the hypothesis that parenterally injected hematoporphyrin derivative (HPD), which is concentrated in tumors and atherosclerotic plaques, localizes in the vegetations of experimental infective endocarditis. In 14 rabbits, various bacteria were given intra-arterially immediately after injury to the aortic valve. In 12 additional rabbits, sterile vegetations on the aortic valve were produced by the trauma caused by an indwelling catheter that had been in place over a long period. HPD, 2.5 mg/kg, was injected intravenously 1 to 2 days before the animals were killed in six rabbits with sterile vegetations and in seven rabbits with infected vegetations. In all rabbits, multiple vegetations on the aortic valve leaflets were identified. On exposure to ultraviolet light, strong porphyrin fluorescence of all vegetations, whether sterile or infected, was observed only in rabbits given HPD. In two rabbits given HPD 10 weeks after catheter implantation across the aortic valve, however, only mild fluorescence could be detected in healing endocardial vegetations. In frozen sections of HPD-laden lesions, a patchy distribution of fluorescence was observed that was similar to the pattern of HPD localization in atheromatous plaques. Since vegetations in experimental infective endocarditis selectively concentrate HPD, porphyrins could be useful in the diagnosis and treatment of infective endocarditis.

Subjective estimates of the angiographic severity of coronary artery stenoses show variability and inaccuracy. We therefore tested the accuracy of a newly developed computerized image analysis system for quantitating vessel diameter from cineangiograms. Fourteen cylindrical phantoms of known diameter were filled with contrast medium and filmed over a wide range of clinically relevant radiographic conditions in order to develop regression equations that related computer-derived to anatomic diameters. Computer measurements of vessel diameter were unaffected by vessel size, magnification, focal spot size, thickness of scattering medium, kilovolt peak, or location within the radiographic field, but a correction factor was necessary for a small but significant (p less than .01) linear dependence on contrast medium concentration. The accuracy of computerized vessel diameter measurements ranged between +/- 59 and +/- 137 mu for all conditions except for rapid vessel motion and contrast medium concentrations of 50% or less meglumine diatrizoate (Renografin 76), both of which resulted in reduced accuracy as well as in the inability to locate lumen edges of vessels less than 1 mm in diameter.

The feasibility of using continuous on-line recording of intraventricular electrical impedance to measure ventricular stroke volume was assessed in 12 patients at cardiac catheterization with a multielectrode impedance catheter and a 1.3 kHz measuring current of 4 microA. Stroke volumes determined by electrical impedance were compared with stroke volumes determined by the thermodilution technique in 10 patients and correlated with an r value of .95. Directional changes in impedance recordings throughout the cardiac cycle were also compared with volume curves obtained from six patients by radionuclide ventriculography, and in all instances the agreement between the two volume recordings was excellent. For all patients, on-line measurements of impedance showed a beat-by-beat decrease in stroke volume with the Valsalva maneuver and the administration of amyl nitrite, as well as an immediate increase in stroke volume in the contraction following an extra-systolic beat. Similar directional changes in stroke volume were recorded in both left and right ventricles. Left ventricular pressure-volume relationships were assessed with simultaneous left ventricular pressure recordings and volume signals recorded from the impedance catheter to determine if impedance measurements of volume can be used clinically. Pressure-volume diagrams were subsequently plotted, and for all patients these diagrams showed characteristic isovolumetric contraction and relaxation phases as well as typical ejection and filling periods. Moreover, beat-by-beat sequential pressure-volume diagrams constructed for patients during the administration of amyl nitrite revealed a linear end-systolic pressure-volume relationship.(ABSTRACT TRUNCATED AT 250 WORDS)