Transgraft hemorrhage: a serious complication of low-dose thrombolytic therapy

A 71-year-old woman came to the hospital with a 24-hour-old occlusion of the left limb of an aortoiliac knitted Dacron graft and was treated with an intra-arterial infusion of urokinase, 40,000 U/hr. Although the graft limb was successfully recanalized in 16 hours, the patient suffered a massive retroperitoneal hemorrhage through the wall of the graft. Clinicians must be aware of this potentially serious complication of thrombolytic therapy in patients with thrombosed, knitted Dacron grafts.     

In situ saphenous vein bypass grafts: angiographic evaluation and interventional repair of complications

In situ saphenous vein grafts are being used with increasing frequency for bypass procedures involving the femoral and popliteal arteries. Complications of these procedures include anastomotic stenoses and persistent arteriovenous fistulae that may result in failure of the graft. Balloon angioplasty and embolotherapy with detachable balloons were employed successfully in three or four recent cases of patients with complications from in situ grafts. Tailored angiography is essential for evaluating in situ grafts, and interventional techniques are extremely useful for managing complications.     

Inpatient admissions for interventional radiology: philosophy of patient management

As an alternative to performing interventional radiology on inpatients under the care of internists and surgeons, the authors have established a cardiovascular radiology admitting service for well-screened, elective patients. The patients are admitted under the care of a cardiovascular radiology fellow and a staff physician. From April 1982 to December 1983, 133 patients were admitted to the service. Patients are cared for in a surgical ward or in an intermediate unit, as determined by the clinical situation. Advantages of this approach include a broader patient referral base, improved rapport with clinical colleagues and patients, improved follow-up data, and rapid evaluation and treatment, resulting in short hospital stays. The major disadvantages involve the commitment of time and staff necessary to provide quality care. The concept of the interventional radiologist in the role of admitting physician has important implications in terms of negotiations for additional financial compensation, commensurate with the skill and time required for performing these procedures and caring for the patient.     

Results of randomized controlled trials of low-versus high-osmolality contrast media

The authors reviewed 100 randomized controlled trials (RCTs) conducted in humans to compare safety or efficacy of new low-osmolality contrast media (LOM) with that of high-osmolality contrast media (HOM). Findings of the 43 RCTs judged to be of the highest quality suggest that the efficacy of LOM in imaging is equal or superior to that of HOM for all routes of administration. Heat sensation occurred less often with LOM for all routes and pain occurred less often with LOM for intraarterial routes. No differences were seen in nephrotoxicity or in frequency of nausea, vomiting, urticaria, bronchospasm, laboratory test abnormalities, or neurologic events. Greater cardiovascular changes were seen with HOM, including increased or decreased heart rate, increased left ventricular end-diastolic pressure, decreased systolic pressure, and QT prolongation, depending on route of administration. To demonstrate whether a reduction in clinically significant adverse outcomes truly occurs with LOM, trials will need to enlist larger numbers of patients and employ appropriate outcome measures. Future trials should stratify patients according to their risk of adverse reactions to provide better information about benefits of LOM in low- versus high-risk patients.     

Psychiatrists' practices and perceptions regarding anticipatory guidance on firearms

BACKGROUND: Most suicides (60%) and homicides (67%) are committed with firearms. Additionally, 90% of homicide offenders and 80% of individuals reporting suicide behaviors meet diagnostic criteria for mental illness. Medical society guidelines support the counseling of patients regarding firearms. This study assessed psychiatrists' anticipatory guidance on firearms and their perceived roles on this topic. METHOD: A four-wave mail survey of adult psychiatrists in Ohio was conducted and analyzed. The outcome measures were the portion of psychiatrists involved in anticipatory guidance on firearm safety issues and their self-efficacy and perceived barriers regarding firearm counseling. RESULTS: Two hundred and five psychiatrists of a possible 340 (60%) responded. Almost half (45%) had never thought seriously about discussing firearm safety issues with patients. They perceived firearm safety issues to be much greater (32%) or slightly greater (37%) for mental health patients than for the general population. Psychiatrists with high efficacy expectations were twice as likely (56.5% vs 28.0%) as those with low efficacy expectations to provide firearm anticipatory guidance. Those who counseled their patients were 15 times more likely to have high outcome expectations compared to those who did not counsel their patients (93.7% vs 6.3%, respectively). CONCLUSIONS: When psychiatrists are provided with firearm information, they were significantly more likely to be involved in anticipatory guidance regarding firearms. This implies that professional societies and journals should attempt to increase the information they provide to their members regarding this topic. Psychiatrists may be in a unique position to help reduce firearm morbidity and mortality for mentally ill patients.     

Airborne measurements of organic bromine compounds in the Pacific tropical tropopause layer

Very short-lived brominated substances (VSLBr) are an important source of stratospheric bromine, an effective ozone destruction catalyst. However, the accurate estimation of the organic and inorganic partitioning of bromine and the input to the stratosphere remains uncertain. Here, we report near-tropopause measurements of organic brominated substances found over the tropical Pacific during the NASA Airborne Tropical Tropopause Experiment campaigns. We combine aircraft observations and a chemistry−climate model to quantify the total bromine loading injected to the stratosphere. Surprisingly, despite differences in vertical transport between the Eastern and Western Pacific, VSLBr (organic + inorganic) contribute approximately similar amounts of bromine [∼6 (4−9) parts per thousand] to the stratospheric input at the tropical tropopause. These levels of bromine cause substantial ozone depletion in the lower stratosphere, and any increases in future abundances (e.g., as a result of aquaculture) will lead to larger depletions.Until the end of the last century, it was believed that only long-lived species, like bromomethane (CH₃Br) and halons, contributed to the global burden of stratospheric bromine. However, disagreement between the observed amount of reactive stratospheric bromine and the sources of long-lived trace gases suggested the existence of an additional contributor: Very short-lived brominated substances (VSL_org) [VSL_org = bromoform (3CHBr₃) + dibromomethane (2CH₂Br₂) + minor_VSLBr, where minor_VSLBr = bromochloromethane (CH₂BrCl) + dibromochloromethane (2CHBr₂Cl) + bromodichloromethane (CHBrCl₂)] that originate mainly from ocean biogenic sources (1, 2).Several studies have described the processes involved in the transformation of biogenic bromocarbons to inorganic bromine, and their transport through the tropical tropopause layer (TTL) (1–5). These studies have led to significant progress in modeling the VSL_org contribution to the formation of stratospheric inorganic bromine (Br_y) (3, 4, 6–11). However, the scarcity of observations to constrain the emissions, the impact of deep convection, and the effect of dehydration processes limit the prediction of short-lived source gases that reach the stratosphere (3). On the other hand, atmospheric observations of VSL_org have been provided by ground measurements and cruise, balloon, and airborne campaigns (12–14), but the different instruments used between campaigns, and the low spatial and temporal coverage of each study, contribute to the uncertainties in the estimations of total bromine and its partitioning (15). In an attempt to reduce these limitations, we present unique measurements of organic bromine substances carried out with the same instrument, the Global Hawk Whole Air Sampler (GWAS), deployed during the NASA Airborne Tropical Tropopause Experiment (ATTREX), which covered the tropical Pacific region during 2013 and 2014 (see SI Text for details of the campaign).Because coastal areas of tropical waters (like the Maritime Continent) are an important source for VSL_org (16–18) and highly convective zones can transport air masses from the troposphere into the stratosphere through the TTL (19), we focus this study on observations taken over the Western Pacific (120°E−165°E) and the Eastern Pacific (187°E−268°E) (Fig. S1). We compared these regions in terms of VSL_org mixing ratios at the tropopause level (∼17 km; Fig. S2), which defines the chemical composition of air that enters the stratosphere.Open in a separate windowFig. S1.GWAS sample locations during ATTREX campaign. Dotted lines define the Western (120°E–165°E) and Eastern Pacific (187°E–268°E) limits for this study.Open in a separate windowFig. S2.Sample density of measurements of organic bromine species (A) during ATTREX-2014 (Western Pacific) and (B) during ATTREX-2013 (Eastern Pacific).Whole air samples were collected during two deployments of the ATTREX campaigns, on board the unmanned aerial vehicle Global Hawk. Measurements of VSL_org were carried out in the field using a combination of gas chromatography with mass selective, flame ionization, and electron capture detectors (Materials and Methods). Fig. 1 A and B displays the observations of CHBr₃, CH₂Br₂, and minor_VSLBr, as well as the total organic bromine mixing ratio, in the upper troposphere/lower stratosphere (UTLS) of the Western and Eastern Pacific. GWAS observations indicate that the total amount of VSL_org that enters the stratosphere over the Western and Eastern Pacific is approximately similar, 3.27 ± 0.47 parts per thousand (ppt) and 2.96 ± 0.42 ppt, respectively. These observations are compared with the state-of-the-art Community Atmosphere Model (CAM-Chem) simulations (4, 20) (see Materials and Methods). The results show good agreement with the measurements, and simulate the injection of VSL_org to the stratosphere of 3.84 ± 0.64 ppt and 3.18 ± 1.49 ppt organic Br for the Western and Eastern Pacific, respectively (Fig. 1 A and B).Open in a separate windowFig. 1.GWAS measurements and CAM-Chem simulations ±1 SD. Filled symbols are the 1 km average bins from GWAS measurements. Lines are the CAM-Chem simulation. Values from the arrows represent the mean mixing ratio (ppt) of VSL_org and Br_y at the tropopause level (∼17 km) derived from CAM-Chem simulations. (A and B) Organic brominated species multiplied by their atomicity for (A) Western Pacific and (B) Eastern Pacific. (C and D) CAM-Chem estimations of inorganic bromine (Br_y) from measured brominated VSLS with shaded ±1 SD for (C) Western Pacific and (D) Eastern Pacific.Although negligible differences of the organic fraction of VSLBr were observed between the Western and Eastern Pacific, we quantified the inorganic fraction coming from the degradation of VSL_org. Estimations of inorganic bromine (Br_y = Br + BrO + HOBr + BrONO₂ + HBr + BrCl + 2Br₂ + BrNO₂ + IBr), with a focus at ∼17 km, were calculated with the CAM-Chem model using assimilated meteorological fields for each Global Hawk flight. According to these simulations, the amount of Br_y over the Eastern Pacific is 3.02 ± 1.90 ppt, whereas, in the Western Pacific, the mixing ratio of Br_y is 1.97 ± 0.21 ppt (Fig. 1 C and D). Br_y/VSL_org ratios show that at ∼17 km, the abundance of Br_y over the Western Pacific is almost half the amount of VSL_org, in contrast to the Eastern Pacific, where the abundance of Br_y is similar to the value of VSL_org (

Pulmonary arteriovenous malformations: techniques and long-term outcome of embolotherapy

Over a 10-year period, 276 pulmonary arteriovenous malformations (PAVMs) were occluded with balloon embolotherapy in 76 patients, 67 (88%) of whom had hereditary hemorrhagic telangiectasia. Eleven patients (14%) were discovered by means of family screening with measurement of arterial blood gases and chest radiography. Epistaxis, dyspnea, hemoptysis, and hemothorax occurred in 79%, 71%, 13%, and 9% of patients, respectively. Clinical histories of strokes and transient ischemic attacks were present in 18% and 37% of patients, respectively. Computed tomographic scans of 59 patients showed stroke in 36%. Sixty-five percent of PAVMs were located in the lower lobes, which correlated with the finding of more pronounced hypoxemia in the upright position. After embolotherapy, symptomatic hypoxemia was corrected, and serial values have remained constant for 5 years. Complications were minimal, and no patient required surgery. Balloon embolotherapy is effective long-term therapy for PAVMs, and family screening should be pursued because of the possibility of a higher frequency of paradoxical embolization (stroke) than previously recognized.