Nasal Foreign Bodies: A Sweet Experiment.

INTRODUCTION: It is generally accepted that paediatric intranasal foreign bodies should be removed in the emergency setting. In the case of a difficult to access dissolvable foreign body in an uncooperative child, the question must be raised regarding whether or not a watch and wait strategy is more appropriate. We ask: How long does it take for popular sweets (candy) to dissolve in the human nose? METHODS: Five popular UK sweets were placed in the right nasal cavity of a 29-year-old male (the author) with no sino-nasal disease. Time taken to dissolve was recorded. RESULTS: All five sweets were completely dissolved in under one hour. DISCUSSION: A watch and wait strategy in favour of examination under anaesthetic may be a viable option in some cases. Limitations of the study include the age of the participant and size of the sweets. It is also important in practice that the clinician is able to elicit an accurate history regarding the exact nature of the foreign body. CONCLUSION: It remains prudent to perform an examination under anaesthetic of an uncooperative child with a solid or unknown nasal foreign body. However, if the clinician can be certain the foreign body is a small sugar or chocolate based sweet only, a watch and wait strategy may be a reasonable choice.

Determination of the photolysis rate coefficient of monochlorodimethyl sulfide (MClDMS) in the atmosphere and its implications for the enhancement of SO2 production from the DMS + Cl2 reaction.

In this work, the photolysis rate coefficient of CH3SCH2Cl (MClDMS) in the lower atmosphere has been determined and has been used in a marine boundary layer (MBL) box model to determine the enhancement of SO2 production arising from the reaction DMS + Cl2. Absorption cross sections measured in the 28000-34000 cm(-1) region have been used to determine photolysis rate coefficients of MClDMS in the troposphere at 10 solar zenith angles (SZAs). These have been used to determine the lifetimes of MClDMS in the troposphere. At 0° SZA, a photolysis lifetime of 3-4 h has been obtained. The results show that the photolysis lifetime of MClDMS is significantly smaller than the lifetimes with respect to reaction with OH (≈ 4.6 days) and with Cl atoms (≈ 1.2 days). It has also been shown, using experimentally derived dissociation energies with supporting quantum-chemical calculations, that the dominant photodissocation route of MClDMS is dissociation of the C-S bond to give CH3S and CH2Cl. MBL box modeling calculations show that buildup of MClDMS at night from the Cl2 + DMS reaction leads to enhanced SO2 production during the day. The extra SO2 arises from photolysis of MClDMS to give CH3S and CH2Cl, followed by subsequent oxidation of CH3S.

Early and eighteen month clinical outcomes of first UK case of percutaneous deep vein arterialisation (pDVA) to treat "no option" chronic limb-threatening ischemia using the LimFlow system.

BACKGROUND: Chronic limb-threatening ischaemia (CLTI) in cases where there are no further standard treatment options for limb salvage represents the most advanced stage of peripheral arterial disease. For these "no-option" CLTI patients, an experimental treatment of foot vein arterialisation (FVA) was first described in 1912, however, it was never widely adopted as outcomes varied significantly most likely due to the complexity of the surgical intervention and lack of standardisation. In recent years there have been significant developments in performing FVA fully percutaneously and standardising the procedure with the introduction of specific indications for patient selection, a dedicated set of devices and structured follow up. This case represents the first UK use of the dedicated LimFlow System as a standardised procedure to perform percutaneous deep vein arterialisation (pDVA) in a "no option" CLTI patient according to the latest treatment recommendations in the literature, with outcomes out to 18 months post-procedure. CASE PRESENTATION: We present the case of a 78 year old male diabetic patient with a history of contralateral below knee amputation who presented with ischaemic rest pain and dry gangrene involving his left heel and first and second toes. Following review by the lower limb multi-disciplinary team at our institution, the patient was deemed to have no surgical or endovascular treatment options, apart from major amputation, as there was no suitable target for either angioplasty or bypass. He was therefore referred as a candidate for percutaneous deep vein arterialisation (pDVA) with the LimFlow System (LimFlow SA, France). After screening of the patient according to the indications for use, the pDVA procedure was successfully performed resulting in complete resolution of ischaemic rest pain immediately following the procedure, and adequate revascularisation of the foot. Following the index procedure, the subject went on to have minor amputation of the first, second and third toes 2 months post initial procedure with further secondary angioplasty procedures to optimise the flow throughout the arterialised circuit up to 4 months after the initial procedure. He underwent elective completion transmetatarsal amputation at 13 months post index procedure. The surgical wounds post minor amputation and the heel wound showed continued healing, especially after secondary optimisation of the pDVA outflow, with tissue epithelialisation by 6 months and complete healing by 18 months after the index procedure. CONCLUSIONS: This case report demonstrates the clinical outcomes of a technically-successful standardised pDVA procedure with the LimFlow system including both limb salvage and wound healing at 18 months. It also highlights the importance of close clinical and radiological surveillance post-index procedure and the requirement for re-interventions to optimise wound healing.

Transcranial focused ultrasound, pulsed at 40 Hz, activates microglia acutely and reduces Aß load chronically, as demonstrated in vivo.

OBJECTIVE: Iaccarino et al. (2016) [1] exposed 1 h of light flickering at 40 Hz to awake 5XFAD Alzheimer's Disease (AD) mouse models, generating action potentials at 40 Hz, activating ∼54% of microglia to colocalize with Aß plaque, acutely, and clearing âˆ¼ 50% of Aß plaque after seven days, but only in the visual cortex. HYPOTHESIS: Transcranially delivered, focused ultrasound (tFUS) can replicate the results of Iaccarino et al. (2016) [1] but throughout its area of application. METHODS: We exposed sedated 5XFAD mice to tFUS (2.0 MHz carrier frequency, 40 Hz pulse repetition frequency, 400 µs-long pulses, spatial peak pulse average value of 190 W/cm2). Acute studies targeted tFUS into one hemisphere of brain centered on its hippocampus for 1 h. Chronic studies targeted comparable brain in each hemisphere for 1 h/day for five days. RESULTS: Acute application of tFUS activated more microglia that colocalized with Aß plaque relative to sham ultrasound (36.0 ± 4.6% versus 14.2 ± 2.6% [mean ± standard error], z = 2.45, p < 0.014) and relative to the contralateral hemisphere of treated brain (36.0 ± 4.6% versus 14.3 ± 4.0%, z = 2.61, p < 0.009). Chronic application over five days reduced their Aß plaque burden by nearly half relative to paired sham animals (47.4 ± 5.8%, z = - 2.79, p < 0.005). CONCLUSION: Our results compare to those of Iaccarino et al. (2016) [1] but throughout the area of ultrasound-exposed brain. Our results also compare to those achieved by medications that target Aß, but over a substantially shorter period of time. The proximity of our ultrasound protocol to those shown safe for non-human primates and humans may motivate its rapid translation to human studies.

Ice flexure forced by internal wave packets in the arctic ocean.

Tiltmeters on the Arctic Ocean were used to measure flexure of the ice forced by an energetic packet of internal waves riding the crest of diurnal internal bores emanating from the Yermak Plateau, north of the Svalbard Archipelago. The waves forced an oscillatory excursion of 36 microradians in tilt of the ice, corresponding to an excursion of 16 micrometers per second in vertical velocity at the surface and of 3.5 millimeters in surface displacement. Strainmeters embedded in the ice measured an excursion of 3 x 10(-7) in strain, consistent with ice flexure rather than compression. The measured tilt is consistent with direct measurements of excursions in horizontal current near the surface (12 centimeters per second) and in vertical displacement (36 meters) of the pycnocline 100 meters below the surface.

A sea change in our view of overturning in the subpolar North Atlantic.

To provide an observational basis for the Intergovernmental Panel on Climate Change projections of a slowing Atlantic meridional overturning circulation (MOC) in the 21st century, the Overturning in the Subpolar North Atlantic Program (OSNAP) observing system was launched in the summer of 2014. The first 21-month record reveals a highly variable overturning circulation responsible for the majority of the heat and freshwater transport across the OSNAP line. In a departure from the prevailing view that changes in deep water formation in the Labrador Sea dominate MOC variability, these results suggest that the conversion of warm, salty, shallow Atlantic waters into colder, fresher, deep waters that move southward in the Irminger and Iceland basins is largely responsible for overturning and its variability in the subpolar basin.

Safety profile of intravitreal triamcinolone acetonide.

BACKGROUND: There is currently a widespread use of intravitreal triamcinolone acetonide (IVTA) for age-related macular degeneration, diabetic macular edema, cystoid macular edema secondary to retinal vein occlusions, and uveitis. The aim of this investigation was to assess the rates of various complications associated with this treatment and to determine which factors are associated with the development of these complications. METHODS: A retrospective interventional case series of all patients from one retina specialist undergoing IVTA was conducted in a clinical setting from 2002 to 2005. All disease entities were included. Patients were followed for a mean of 9.5 months after receiving 4 mg (0.1 mL) of nonfiltered triamcinolone acetonide (TA). All complications associated with the injection procedure or with the TA were noted. RESULTS: Two hundred and twenty-three (223) eyes of 192 patients received a total of 336 IVTA injections between 2002 and 2005. The mean age was 73.3 years and mean follow-up was 9.5 months. A single injection was performed in 144 eyes (64.6%); 2 IVTAs in 55 eyes (24.7%); 3 IVTAs in 16 eyes (7.2%), and 3.6% of eyes had more than 3 injections at a minimal interval of 3 months. The only immediate complication was a single injection (0.3%) associated with a temporary occlusion of the central retinal artery, which opened immediately following anterior paracentesis. Late complications included endophthalmitis in 1 of 336 (0.3%) injections and a steroid response requiring glaucoma medication in 60 of 192 patients (31.3%). In patients with preexisting glaucoma, 58.8% required additional glaucoma medication. Glaucoma-filtering surgery was required in 2 of 192 patients (1.0%). CONCLUSIONS: In the study center, the IVTA is extremely safe in patients without a history of glaucoma. However, patients with preexisting glaucoma with progressive optic neuropathy must be treated with great caution.

Severe retinal injuries from paintball projectiles.

BACKGROUND: To determine the outcomes and circumstances of retinal injuries caused by blunt trauma from paintball pellet projectiles. METHODS: Retrospective case series of all patients who presented with retinal injuries due to paintball-related trauma to 2 retina specialists in a clinical setting from 2004 to 2005. Patients were followed for a mean of 7.3 months, and retinal trauma was documented with retinal photographs and ocular coherence tomography as needed. Best corrected visual acuity (BCVA) was the main outcome measure. RESULTS: Three eyes of 3 patients suffered severe retinal injuries after blunt trauma from a paintball pellet. Together, the 3 eyes demonstrated extensive retinal findings, including commotio retinae, choroidal rupture, and macular hole. BCVA at last follow-up ranged from 20/80 to hand motions. INTERPRETATION: Our small case series indicates that retinal trauma from paintball injuries is not uncommon and results in severe long-term visual morbidity. The sale of paintball guns and pellets should be strictly prohibited for minors, and adults should be educated about the need for appropriate ocular protection and the potentially serious consequences of the use of these guns outside of commercial settings.

Echocardiography in the neonate and young infant.

The neonate and young child present unique problems in echocardiographic diagnosis because of the wide spectrum of possible abnormalities and the tendency toward multiple lesions, requiring clear visualization of all great veins and arteries as well as intracardiac structures. Performance and interpretation of echocardiograms in this age group require an extensive knowledge of the pathologic anatomy of congenital heart disease. Recognition of unusual lesions is facilitated by displaying the heart in an anatomically familiar (upright) format in order to draw from experience in angiography and pathology. The subxiphoid (subcostal) transducer position provides a flexible acoustic window for scanning the heart and great vessels in a multitude of planes, providing a general orientation for each cardiac segment. All other transducer positions are utilized to provide specific anatomic information. Although in this age group echocardiographic visualization of intracardiac anatomy is superior to other techniques, delineation of the great vessels remains its greatest limitation. Tortuous vessels may not lie in a single plane and, therefore, cannot always be displayed throughout its length by a "slice" technique such as echocardiography. In addition, limited focal range of most high frequency transducers is a continuing impediment to imaging structures in the posterior and superior mediastinum. Echocardiography provides a cost-effective means for identifying the neonate with life-threatening cardiovascular disease. It provides a complete and definitive anatomic diagnosis, in some cases eliminating the need for further procedures, while in others, improving the timing and performance of cardiac catheterization. Future studies should investigate the proper utilization of echocardiography as adjunct to or replacement of other techniques in the management of the young child.

Pediatric cardiology in the 1990s.

OBJECTIVES: In 1991, all active board-certified pediatric cardiologists were polled by questionnaire to examine the relation of subspecialty training and motivational and satisfaction issues to practice characteristics. BACKGROUND: Previous questionnaires with regard to manpower status and practice characteristics were published in 1967 and 1980. These indicated a field predominantly centered in academic medicine with growth in manpower close to predicted need. METHODS: The questionnaire was mailed to 844 of 884 active board-certified pediatric cardiologists and was returned anonymously by 570, a 68% response rate. RESULTS: Among respondents, the mean year in which fellowship training was completed was 1974. The average length of subspecialty training was 31 months for all respondents and 34 months among those completing training since 1981. Seventy-seven percent of subspecialty training centered on clinical training. Although there has been a slight increase in research training in recent years, only 18 respondents completed > or = 22 months of research training. Respondents devote a mean of 89% of professional hours to subspecialty activities and spend 63% of total hours in clinical care. Total hours, income and procedures were related to site of professional activity. Professional satisfaction was high in the factors considered more important: professional challenge and interaction, clinical resources, career security and clinical autonomy. CONCLUSIONS: The field of pediatric cardiology is a subspecialty centered on patient care and performance of diagnostic and interventional techniques. Professional activities varied according to practice site. Pediatric cardiologists with basic research training and professional activity remain a minority. Satisfaction is high, with greatest satisfaction in professional interactions and least satisfaction with income and free time.

Subaortic obstruction in complex congenital heart disease: management by proximal pulmonary artery to ascending aorta end to side anastomosis.

Six patients with univentricular heart and one patient with d-transposition of the great arteries had transection of the main pulmonary artery with an end to side anastomosis of the main pulmonary artery to the ascending aorta to relieve subaortic obstruction. Two operations were performed as a palliative procedure within the first 6 months of life and five were performed as part of a definitive repair (four modified Fontan procedures and one repair of transposition of the great arteries with ventricular septal defect). There was one surgical death (14%) occurring 1 day postoperatively from low cardiac output. The remaining six patients are doing well 1 to 19 months postoperatively (mean 11.4 months). The proximal pulmonary artery to ascending aorta end to side anastomosis is an effective means of bypassing subaortic obstruction associated with complex congenital heart disease.

Factors influencing survival of patients with heterotaxy syndrome undergoing the Fontan procedure.

OBJECTIVES: This study was undertaken to determine those factors that may influence survival in patients with heterotaxy syndrome undergoing the Fontan procedure. BACKGROUND: The Fontan procedure remains the preferred palliative procedure for patients with heterotaxy syndrome. Although the mortality rate has improved for patients without this syndrome undergoing the Fontan procedure, it remains high for patients with heterotaxy syndrome. METHODS: The medical records of 20 consecutive pediatric patients with asplenia (n = 12) and polysplenia (n = 8) who underwent the Fontan procedure between January 1, 1986 and December 31, 1990 were reviewed. Anatomic and hemodynamic data were collected, as well as data on types of surgical palliative procedures and on outcome of the Fontan procedure. RESULTS: There were two early and two late deaths for a total mortality rate of 20% in the patients with heterotaxy syndrome, as compared with 8.5% for the patients without this syndrome who underwent the Fontan procedure during the same time period. Factors that significantly increased the risk of the Fontan procedure in these patients were 1) preoperative findings of greater than mild atrioventricular valve regurgitation, b) hypoplastic pulmonary arteries, and c) mean pulmonary artery pressure greater than or equal to 15 mm Hg after 6 months of age. Systemic and pulmonary venous anomalies coupled with single-ventricle anatomy were not significant risk factors for determining a poor outcome of the Fontan procedure. CONCLUSIONS: This study suggests that the outcome of the Fontan procedure in patients with heterotaxy syndrome may be improved by early protection of the pulmonary vascular bed, despite the existence of other cardiac anomalies.

Repair of conotruncal abnormalities with the use of the valved conduit: improved early and midterm results with the cryopreserved homograft.

Repair of complex cardiac lesions has been facilitated by the availability of valved conduits to reestablish right ventricular to pulmonary artery continuity. From 1977 to June 1991, 148 patients underwent repair with insertion of a conduit. Their mean age was 6.6 years (11 days to 45 years). The diagnosis was transposition of the great arteries with ventricular septal defect and left ventricular outflow tract obstruction in 51, truncus arteriosus in 36, pulmonary atresia with ventricular septal defect in 25, tetralogy of Fallot in 19, double-outlet right ventricle in 10, pulmonary atresia with intact ventricular septum in 6 and atrioventricular canal with pulmonary atresia in 1. A Dacron porcine-valved conduit was used in 37, a homograft conduit in 106 and a nonvalved conduit in 5. There were 13 early deaths overall (8.8%); 8 (22%) of the early deaths occurred in the 37 patients who received a Dacron graft, 4 (3.8%) occurred in the 106 patients who received a homograft and 1 occurred in a patient with a nonvalved Gore-Tex conduit. An additional patient underwent orthotopic heart transplantation in the early postoperative period. In 117 patients operated on from January 1985 to June 1991 the early mortality rate was 2.6% (3 of 117). Among 28 patients receiving a Dacron porcine-valved graft there were two late deaths (7.1%) after a mean follow-up interval of 93 months, and 8 patients required reoperation for conduit obstruction. Among 102 homograft recipients there were two late deaths (1.9%).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute hemodynamic effects of adjustable atrial septal defect closure in the lateral tunnel Fontan procedure.

OBJECTIVES: This study evaluated the acute hemodynamic changes with atrial septal defect closure in the postoperative period in patients undergoing the Fontan procedure. BACKGROUND: The adjustable atrial septal defect is a modification of the Fontan procedure designed to improve cardiac output and reduce systemic venous hypertension during the postoperative period. Limited information is available on the effects of inter-atrial shunting on the physiology of direct cavopulmonary connection. METHODS: In 11 patients (aged 9 months to 14.5 years), the atrial septal defect was closed 8 h to 4.6 days (mean 1.7 days) postoperatively. Indications for closure included mean right atrial pressure < 15 mm Hg or arterial oxygen saturation < 80%, or both. RESULTS: Data presented are mean values +/- 1 SD. Mean right atrial pressure was 13.4 +/- 3.0 mm Hg on admission to the intensive care unit, 10.0 +/- 2.0 mm Hg (p = 0.02) immediately before closure and 11.4 +/- 2.8 mm Hg (p = 0.02) after closure. There was a significant decrease in cardiac output, as calculated from arteriovenous oxygen saturation difference (26 +/- 9%, p = 0.003), Doppler aortic flow (19 +/- 9%, p = 0.0002) and ventricular volumes by two-dimensional echocardiography (20 +/- 8%, p = 0.0001). Arterial oxygen saturation increased from 82 +/- 5% to 94 +/- 4% (p = 0.0001), and arteriovenous oxygen saturation difference increased from 25 +/- 8% to 33 +/- 9% (p = 0.0001). Systemic oxygen delivery decreased from 727 +/- 354 to 655 +/- 325 ml/min per m2 (p = 0.02). One patient required reopening of the atrial septal defect. CONCLUSIONS: These data demonstrate that a controlled right to left atrial shunt improves cardiac output and systemic oxygen delivery and facilitates the postoperative management of patients after the Fontan procedure. Atrial septal defect closure increases systemic saturation to normal values and prevents potential systemic embolization but significantly decreases oxygen delivery and might limit exercise tolerance.

[125I]-omega conotoxin binding to human frontal cortex from normal, Alzheimer's and non-Alzheimer's dementia patients.

We studied the binding of the calcium antagonist neurotoxin [125I]-omega conotoxin (GVIA) in age-matched human brains from normal, Alzheimer's disease and non-Alzheimer's dementia patients. Crude preparations of plasmalemmal membranes from frontal cortex were utilized. Saturation isotherms were subjected to Scatchard analysis to determine maximal binding capacity (Bmax) and binding affinity (Kd). In all brain samples tested, [125I]-GVIA binding was homogenous to a single class of high affinity binding sites. Scatchard analysis of saturation isotherms gave the following estimates for normal brains (mean +/- S.D., n = 7): Bmax = .630 +/- .200 pmol/mg and Kd = .177 +/- .054 nM. No significant change was observed in the Kd or Bmax estimates for [125I]-omega conotoxin binding in Alzheimer's disease or non-Alzheimer's dementia brains when compared to normal brains. Although these findings do not rule out the existence of localized changes in calcium channel receptor binding in the frontal cortex of Alzheimer's disease patients, the results do suggest that the neuronal voltage sensitive calcium channel may be unaltered in Alzheimer's disease.

Distribution of enkephalin-related peptides in rat brain: immunohistochemical studies using antisera to met-enkephalin and met-enkephalin Arg6Phe7.

The enkephalin-related heptapeptide, Tyr-Gly-Gly-Phe-Met-Arg-Phe, forms the C-terminus of a biosynthetic precursor that contains both Met-enkephalin and Leu-enkephalin sequences. We have studied the distribution of heptapeptide-like immunoreactivity in rat brain by immunohistochemistry using a C-terminal specific antiserum. The results were compared with those obtained using an antiserum specific for the C-terminus of Met-enkephalin which does not react with C-terminally-extended variants. Both antisera specifically stained cell bodies and fibres in many regions of the rat central nervous system. Colchicine was needed for the demonstration of cell bodies with the Met-enkephalin antiserum, but not for the heptapeptide antiserum. In the nucleus of the solitary tract, in the commissural nucleus, the nucleus raphe obscurus and in the hypothalamus, studies of serial sections and re-staining experiments indicated that the two antisera stained the same cell bodies. However, in the olfactory bulb, the anterior olfactory nucleus, the olfactory tubercle, the nucleus accumbens, caudate-putamen, central nucleus of the amygdala, nucleus interstitialis striae terminalis, pre-lateral mamillary nuclei, ventral hypothalamus, hippocampus, peri-aqueductal grey and the granular layer of the cerebellum, cells were stained by the heptapeptide antiserum but not the Met-enkephalin antiserum. The two antisera revealed similar patterns of staining of nerve fibres in many regions including hypothalamus, central nucleus of the amygdala, lateral septum, thalamus, mid-brain and spinal cord. But in other areas notably, pallidum, caudate-putamen, substantia inominata, nucleus of the solitary tract and commissural nucleus, there were abundant fibres and terminals revealed by the Met-enkephalin antiserum but not by the heptapeptide antiserum. The results are discussed with respect to possible patterns of enkephalin biosynthesis; it is suggested that in some neurones immunoreactive enkephalin precursors terminating in the heptapeptide sequence are processed to produce the heptapeptide which is stored in terminals and is available for release as an endogenous opioid agonist in its own right. In other cases, however, it is suggested that the heptapeptide might be cleaved by removal of -Arg-Phe to yield Met-enkephalin which is the primary opioid product of this class of neurone.

Sensory substance P-innervation of the urinary bladder: possible site of action of capsaicin in causing urine retention in rats.

In rats treated neonatally with capsaicin there is, in later life, a tendency tendency towards urine retention. Since capsaicin is known to cause irreversible loss of certain primary sensory neurons, notably those containing substance P, we have studied the sensory innervation of the bladder in capsaicin-treated and control rats using retrograde tracing methods and immunohistochemistry; in addition, the motor function of the bladder was assessed in in vitro experiments, using electrical field stimulation. Five days after injection of the fluorescent tracer True Blue into the wall of the bladder, numerous labelled cells were identified in dorsal root ganglia T13, L1, L2, L6, and S1 and smaller numbers of cells were found in T12 and L3. In capsaicin-treated rats the numbers of labelled cells were reduced by over 50% in L1, L6 and S1. In control rats, 10-16% of True Blue labelled cells also contained substance P as demonstrated by indirect immunofluorescence, but in capsaicin-treated rats substance P cells were virtually absent. In in vitro studies, contractions of the detrusor muscle to electrical field stimulation, both before and after atropine, were similar in control and capsaicin-treated rats. We suggest that capsaicin causes urine retention in rats due to an impairment of sensory transmission from the bladder (that could involve substance P) and a consequent failure in the normal micturition reflexes.

Training pediatricians for the evolving generalist-specialist interface in the managed care era.

Managed care involves the linkage of service delivery and financing. One of the outgrowths of the rapid expansion of managed care over the past decade has been an increasing consensus that the generalist of the future will need to manage more of the patients traditionally cared for by subspecialists. Subspecialty education for pediatric residents becomes increasingly important as the role of the pediatric generalist enlarges to include independent outpatient management of some less complex but traditional subspecialty patients as well as collaborative management of more complex patients. To prepare for this role, a balanced exposure to subspecialty problems in outpatient as well as inpatient settings is required. At the same time, however, the growth of managed care has led to certain barriers for providing this enhanced training. This article describes the effects of managed care on the role and scope of the pediatric subspecialist as well as on educational strategies for coping with these changes while reshaping the roles of both generalists and subspecialists for maximal effectiveness in meeting the health care needs of children.

Measurement of systemic and pulmonary blood flow and QP/QS ratio using Doppler and two-dimensional echocardiography.

A noninvasive method for measuring systemic and pulmonary blood flow using Doppler velocimetry combined with 2-dimensional (2-D) echocardiography has been developed. High correlations were found between Fick- and Doppler-derived indexed measurements of systemic and pulmonary flow as well as the pulmonary to systemic flow ratio in 33 patients undergoing cardiac catheterization (systemic flow [n = 28], r = 0.78; pulmonary flow [n = 21], r = 0.88; Qp/Qs ratio [n = 24], r = 0.85). The random errors of the 2 methods were not significantly different. Outflow tract obstruction, semilunar valve regurgitation, and patent ductus arteriosus were the only lesions in which limitations to the use of this method were encountered. We anticipate that this method will be of use in initial and serial evaluations of adult and pediatric patients with low cardiac output or intracardiac shunts.

Conotruncal malformations: diagnosis in infancy using subxiphoid 2-dimensional echocardiography.

Subxiphoid 2-dimensional echocardiography was performed and interpreted before the first cardiac catheterization of 109 of 113 infants less than 1 year of age with conotruncal malformations, situs solitus of the atria, and d-ventricular loop. The 4 remaining infants could not be examined using this technique for technical reasons. In 104 of 109 patients successfully examined a correct diagnosis was obtained with the use of subxiphoid 2-dimensional echocardiography. All patients with d-transposition of the great arteries had a correct diagnosis, and in 10 of 11 patients various types of double-outlet right ventricle were recognized by direct visualization of ventriculoarterial connection. Tetralogy of Fallot was correctly diagnosed in 34 of 36 patients and tetralogy of Fallot and pulmonary atresia were correctly diagnosed in 8 of 9 patients, on the basis of the position of the infundibular septum and presence or absence of continuity between the main pulmonary artery and the right ventricular. Five of 6 patients with truncus arteriosus communis were correctly diagnosed by demonstrating a connection between the pulmonary arteries and the ascending portion of the single large semilunar root. Subxiphoid 2-dimensional echocardiography proved to be a sensitive and specific technique for diagnosing conotruncal malformations in infancy.