Transesophageal echocardiography to evaluate patients with severe pulmonary hypertension for lung transplantation.

The surgical approach to lung transplantation for patients with severe pulmonary hypertension will be dependent on the primary disease and specific cardiac anatomy. To determine the safety and utility of transesophageal echocardiography in the management of patients with severe pulmonary hypertension who are being evaluated for lung transplantation, we studied 48 consecutive patients, aged 38 +/- 11 years, with pulmonary artery systolic pressure of 70 mm Hg or greater. All patients previously underwent left and right heart catheterization, transthoracic echocardiography, and radionuclide ventriculography. Transesophageal echocardiography was tolerated well by all patients. Additional data that significantly altered surgical therapy was found in 12 of 48 patients (25%): proximal pulmonary artery thrombi (3), patent foramen ovale with significant right to left shunting (2), atrial septal defect (2), double-outlet right ventricle (2), ventricular septal defect (2), and exclusion of atrial septal defect (1). These findings were confirmed surgically in all patients except 3, who died awaiting transplantation. Transesophageal echocardiography is useful in the evaluation of patients with severe pulmonary hypertension.

Myocardial ischemia after orthotopic liver transplantation.

A hypercoagulable state exists after orthotopic liver transplantation. This hematologic abnormality may predispose patients to coronary thrombosis and unstable angina. The incidence of postoperative myocardial ischemia in such patients is unknown. Suitable electrocardiograms and clinical events of consecutive patients undergoing orthotopic liver transplantation (n = 45) and major intraabdominal surgery (n = 28) during a 3-month period at a major university teaching hospital and transplant center were examined retrospectively. Clinical myocardial ischemia or ischemic electrocardiographic changes, or both, occurred in 6 transplant patients compared with no patient in the nontransplant or comparison group. In 4 of the 6 patients with dramatic electrocardiographic changes and ischemic events, coronary arteriography failed to demonstrate significant obstructive disease. It is concluded that severe myocardial ischemia may occur in patients after orthotopic liver transplantation in the absence of significant coronary disease. A hypercoagulable state may predispose to coronary thrombosis in this setting, providing insight (and a future model for study) into the development of unstable angina.

Diastolic dysfunction in cardiac transplant recipients: an important role in the response to increased afterload.

We evaluated the hemodynamic and functional response to acute elevations in left ventricular (LV) afterload in 22 recent recipients of cardiac transplants to determine whether abnormalities in LV diastolic function influence the response to this intervention. In seven patients (group 1) LV ejection fraction decreased significantly from baseline values (> or = 5%) during methoxamine infusion, whereas in 15 patients (group 2) LV ejection fraction was maintained. Peak filling rate was lower in group 1 versus group 2 (3.36 +/- 0.46 vs 4.23 +/- 0.68 end-diastolic volumes/sec, p < 0.01). In addition, patients in group 1 did not have LV dilatation during methoxamine (percentage change in end-diastolic counts, -3.4 +/- 6.9%) and had a large increase in pulmonary artery wedge pressure. In contrast, patients in group 2 had LV dilatation (percentage change in end-diastolic counts, +10.7 +/- 14.7%) and a smaller increase in pulmonary artery wedge pressure. There was a relationship between the baseline peak filling rate and the change in LV ejection fraction during methoxamine (r = 0.65, p = 0.001). Therefore in a subset of cardiac transplant patients, abnormalities in LV filling can have an impact on the response to increased afterload.

Verapamil overdose: case report and review of the literature.

OBJECTIVE: To report the presentation and controversies regarding therapy of an 18-year-old man following a life-threatening ingestion of verapamil. CASE SUMMARY: An 18-year-old man ingested large quantities of dipyridamole, trimethoprim/sulfamethoxazole, amoxicillin, and verapamil. He presented to an outlying hospital and was initially conscious. Soon thereafter, the patient had a seizure; he required intubation, developed cardiac conduction abnormalities, and became hypotensive. The patient required pharmacologic pressors and a pacemaker for transfer to our institution. At our institution, vigorous fluid resuscitation, cardiac pacing, and careful attention to acid/base and electrolyte management provided the basis of therapy. The patient recovered without deficit and was discharged from the intensive care unit five days later. DISCUSSION: Current controversies regarding the management of verapamil overdose are reviewed. Removal of the drug by gastric lavage is a mainstay of therapy. Administration of syrup of ipecac is contraindicated. Although specific recommendations for calcium dosing in the overdose situation have not been rigorously studied, maintenance of a normal serum ionized calcium concentration is suggested. An exogenous catecholamine, rather than dopamine, may be the drug of choice for treating hypotension. Cardiopulmonary bypass provides a method for drug removal in cases of severe toxicity; however, this invasive method requires further study. Management of fluid/electrolyte, acid/base, and ventilation abnormalities is required to treat large ingestions of verapamil. Treatment guidelines for critical care clinicians are provided.

Efficacies of mixtures of disinfectants and insecticides.

Efficacies of mixtures of diluted commercial formulations of selected insecticides and disinfectants were evaluated. Insecticides tested included representative pyrethroids (fenvalerate [Ectrin WDL and WD] and permethrin [Ectiban EC]), organophosphates (dichlorvos [Vapona EC], tetrachlorvinphos [Rabon WP] and dichlorvos/tetrachlorvinphos [RaVap EC], and a carbamate (carbaryl [Sevin S]). Disinfectants tested included representatives of cresylic acid (Biolene), cresylic acid/phenol (BioGuard X-185), phenol (1-Stroke Environ), quaternary ammonium (BioGuard S-3 and PFP-4), quaternary ammonium/formalin (DC & R), and formalin classes of disinfectants. Mixtures were tested for toxicity to two target insects (Musca domestica on plywood, Alphitobius diaperinus in litter) and two bacteria (Pseudomonas aeruginosa and Staphylococcus aureus). Of 56 mixtures evaluated, 24 showed reduced insecticidal toxicity and 35 showed reduced bactericidal activity compared with insecticides or disinfectants alone.

Efficacy and nontarget effects of Larvadex as a feed additive for controlling house flies in caged-layer poultry manure.

The insect growth regulator N-cyclopropyl-1,3,5-triazine-2,4,6 triamine (Larvadex, CGA 72662, cyromazine) was provided as a feed additive (.3% Premix per ton of feed) to caged laying hens under field conditions in high rise, wide span and narrow poultry houses. The chemical effectively controlled house flies (Musca domestica) and soldier flies (Hermetia illucens). The feed additive had no adverse effect on the populations of manure-inhabiting mites (Macrochelidae and Uropodidae) and histerid beetles (Carcínops pumulio), which prey on fly eggs and larvae. Satisfactory fly control was demonstrated by use of the additive 50% of the time when the interval without the additive in the feed was 4 days but not when the interval was 7 days. Use of a fly monitoring program to time the use of the feed additive is advocated.