Cardiac dysrhythmias associated with ophthalmic atropine.

Atropine sulfate, a mydriatic and cycloplegic agent, is frequently used in patients undergoing glaucoma surgery. Trabeculectomy with peripheral iridectomy is the most common glaucoma surgery performed to decrease intraocular pressure and preserve vision. Systemic absorption of ophthalmic atropine does occur and may result in toxic and adverse side effects. Cardiac dysrhythmias are one of the major adverse reactions. This case study reviews three patients who had a trabeculectomy for glaucoma and received ophthalmic atropine. One patient received both systemic and ocular atropine. Two patients developed atrial fibrillation and one a supraventricular tachycardia. Two patients required admission to a cardiac intensive care unit for management of the dysrhythmia and a third reverted to normal sinus rhythm spontaneously. The cardiac effects of ophthalmic atropine should be considered in the preoperative and postoperative assessment of patients with dysrhythmias.

Use of enoxaparin for the chronically anticoagulated patient before and after procedures.

Patients who require chronic anticoagulation and a procedure have been traditionally managed either by stopping warfarin and starting intravenous standard heparin or by adjusted dose subcutaneous standard heparin or taken off all anticoagulation for a week before the procedure. Enoxaparin may be useful as an alternative method of anticoagulation, avoiding hospitalization and the need for frequent monitoring.

Adenosine radionuclide perfusion imaging in the preoperative evaluation of patients undergoing peripheral vascular surgery.

To define the clinical and adenosine test variables that predicted perioperative cardiac events, 122 patients who received adenosine radionuclide perfusion imaging before peripheral vascular surgery were reviewed. Events included pulmonary edema, an ischemic end point of acute myocardial infarction (AMI) or cardiac death. Five patients underwent coronary revascularization before the surgical procedure. Of the 117 remaining patients, 19 had pulmonary edema, 10 had an AMI, and 2 died after peripheral vascular surgery. Most of the patients (78%) were in an intermediate-risk group as indicated by the presence of > or = 1 clinical risk factor as defined by the Eagle criteria. The only predictor of perioperative pulmonary edema was a history of congestive heart failure (33% vs 4%; p = 0.002). No clinical variables predicted AMI or death. The adenosine variables that were univariate predictors of AMI and death were the number of reversible perfusion defects (1.75 +/- 1.84 vs 0.75 +/- 0.90; p = 0.001) and the number of coronary artery distributions with a radionuclide perfusion defect (1.33 +/- 0.64 vs 0.85 +/- 0.67; p = 0.022). The number of reversible perfusion defects was the only multivariate predictor of ischemic events (p = 0.017). The presence of > 1 reversible defect was associated with an increased frequency of ischemic events (68% vs 28%; p = 0.045). The sensitivity and specificity of > 1 reversible defect was 58% and 73%, respectively, with a positive and negative predictive value of 19% and 94%.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of culture conditions on the mycelial growth and luminescence of naturally bioluminescent fungi.

The effects of temperature, light and pH on mycelial growth and luminescence of four naturally bioluminescent fungi were investigated. Cultures of Armillaria mellea, Mycena citricolor, Omphalotus olearius and Panellus stipticus were grown at 5 degrees C, 15 degrees C, 22 degrees C and 30 degrees C, under 24 h light, 12 h light/12 h dark and 24 h dark, and at a pH ranging from 3.5 to 7 in three separate experiments. Temperature and pH had a significant effect on mycelial growth and bioluminescence, however light did not. Bioluminescence and mycelial growth were optimum at 22 degrees C and pH 3-3.5, the exception being M. citricolor for which bioluminescence and growth were optimum at pH 5-6 and pH 4, respectively. With the exception of M. citricolor, bioluminescence and mycelial growth were greater under 24 h darkness. An understanding of the effect of culture conditions on mycelial growth and luminescence is necessary for the future application of bioluminescent fungi as biosensors.

Feasibility of using prokaryote biosensors to assess acute toxicity of polycyclic aromatic hydrocarbons.

The aim of this study was to assess the acute toxicity of polycyclic aromatic hydrocarbons using lux-marked bacterial biosensors. Standard solutions of phenanthrene, pyrene and benzo[a]pyrene were produced using 50 mM hydroxpropyl-beta-cyclodextrin solution which contained each respective polycyclic aromatic hydrocarbon at 6.25 times the aqueous solubility limit of the compound. The polycyclic aromatic hydrocarbon solutions were incubated with each of the biosensors for 280 min and the bioluminescence monitored every 20 min. Over the incubation time period, there was no significant decrease in bioluminescence in any of the biosensors tested with the exception of Rhizobium leguminosarum biovar trifolii TA1 luxAB. In this series of incubations, there was a dramatic increase in bioluminescence in the presence of phenanthrene (2.5 times) and benzo[a]pyrene (3 times) above that of the background control (biosensor without polycyclic aromatic hydrocarbon) after 20 min. Over the next 3 h, bioluminescence decreased to that of the control. An ATP assay was carried out on the biosensors to assess if uncoupling of the oxidative phosphorylation mechanisms in the respiratory chain of the cells had occurred. However, it was found that the polycyclic aromatic hydrocarbons had no effect on the organisms indicating that there was no uncoupling. Additionally, mineralisation studies using 14C-labelled polycyclic aromatic hydrocarbons showed that the biosensors could not mineralise the compounds. This study has shown that the three polycyclic aromatic hydrocarbons tested are not acutely toxic to the prokaryotic biosensors tested, although acute toxicity has been shown in other bioassays. These results question the rationale for using prokaryote biosensors to assess the toxicity of hydrophobic chemicals, such as polycyclic aromatic hydrocarbons.

Construction of a modified mini-Tn5 luxCDABE transposon for the development of bacterial biosensors for ecotoxicity testing.

A mini-Tn5 transposon was modified to introduce a promoterless luxCDABE cassette from Vibrio fischeri into environmentally relevant bacterial strains in order to develop bioluminescence-based biosensors for toxicity testing. The mini-Tn5 luxCDABE transposon was chromosomally integrated downstream from an active promoter into two Pseudomonas strains (Pseudomonas fluorescens 8866 and Pseudomonas putida F1). Characterisation of the bioluminescent transconjugants demonstrated that the transposon integration was stable and had no effect on growth rate. Both P. fluorescens 8866 Tn5 luxCDABE and P. putida F1 Tn5 luxCDABE were used to assess the toxicity of standard solutions (Cu, Zn and 3,5-DCP) as well as Cu- and 3,5-DCP-spiked groundwater samples. They were successfully used for bioluminescence-based bioassays and the potential value of using different bacterial biosensors for ecotoxicity testing was shown.

Cardiac risk stratification prior to vascular surgery.

A cardiac etiology is the cause of death in approximately 40% to 60% of patients who die in the early postoperative period following vascular surgery. A variety of modalities has been proposed to identify the patient at risk before the surgical procedure. This article puts these modalities in perspective and discusses the increased risk of cardiac complication for the vascular surgery patient, identifies the patient at risk, and defines methods to decrease patient risk.

Perioperative cardiac complications.

Although infrequent, perioperative cardiac complications are a source of major morbidity and mortality. As the population ages, the prevalence of cardiovascular disease is increasing. For physicians who refer patients for surgery as well as for clinicians directly involved in perioperative medical care, an understanding of perioperative cardiac complications, reduction of such complications, and treatment of complications is essential. This article summarizes the approach to perioperative hypertension, hypotension, myocardial ischemia, myocardial infarction, and congestive heart failure.

Noncardiac surgery in the patient with heart disease.

Optimal care of the patient with heart disease undergoing noncardiac surgery requires that the members of the surgical team, including anesthesiologist, internist-cardiologist, and surgeon, be familiar with the cardiovascular response to surgery, preoperative cardiac risk stratification, and the unique pathogenesis of cardiac complications that may occur in the perioperative period. Preoperative evaluation and computation of cardiac risk, anesthetic considerations, along with perioperative care of the patient with ischemic heart disease, valvular heart disease, congestive heart failure, arrhythmias and conduction disorders, and hypertension is discussed.

The medical consultant.

This article reviews the historical development of the medical consultant. The major articles that have set the foundation for this art are reviewed. Future directions and a mnemonic for successful consultations are presented.

Approach to the patient with palpitations.

Palpitations are a common complaint present in up to 16% of outpatients. They are nonspecific and in only 15% of patients do they correlate with a cardiac arrhythmia. The significance of palpitations is related to the presence or absence of underlying cardiac disease, the clinical setting in which palpitations occur, and the characteristics and severity of symptoms. This article presents a concise approach to the evaluation of the ambulatory patient with palpitations.

Postoperative arrhythmias and conduction disorders.

Cardiac arrhythmias are common in the perioperative period. Most arrhythmias are clinically benign. Occasionally, cardiac arrhythmias and conduction disturbances can pose a major additional risk to the patient in the perioperative and postoperative periods. The current availability of a wide array of techniques for controlling serious arrhythmias--pharmacologic, electrical, and interventional--enable the physician to manage most arrhythmias and conduction disturbances successfully. The added risks posed by arrhythmias and conduction disturbances in the perioperative period now can be minimized.

Approaching the surgical patient. Role of the medical consultant.

Medical consultants will no longer "clear patients" but will "prepare them" for surgery instead. They will be required to possess the expertise in assessing a patient's risk for surgery, managing perioperative medications, caring for postoperative complications, maintaining appropriate conduct in the role as consultant, and recording accurate documentation of level of service for third party reimbursement.

Cutaneous immunoblastic T-cell lymphoma.

The case of a 69-year-old male patient with an unusual type of malignant lymphoma is presented. Clinically, it was at first characterized by follicular papules and erythematous patches, later, by the development of cutaneous tumors and enlarged lymph nodes, and by a severe, finally excruciating pruritus. Treatment with PUVA (psoralen-ultraviolet-A) combined with 40--80 mg prednisolone and then with chemotherapy [COPP regimen (cyclophosphamide, vincristine, procarbacine, prednisone), high-dosage methotrexate followed by citrovorum factor rescue] was not successful. The patient died of pneumonia 2.5 years after the onset of the first clinical symptoms. An immunoblastic infiltrate was observed histologically and electromicroscopically in the initial lesions of the skin. Therefore, the diagnosis of a cutaneous immunoblastic T-cell lymphoma was tentatively made at the beginning, which was later confirmed in numerous biopsies and laboratory investigations. Immunocytologically and enzymecytochemically, the infiltrating cells were shown to be immature T cells; in the lymph nodes, numerous immunoblasts and large Sézary cells was observed in the peripheral blood, though there were no very large Sézary cells or blast cells. In the autopsy, a systemic involvement with an atypical lymphoid infiltration was found in numerous internal organs. The special nature of this case justifies its classification as high-grade malignant lymphoma and its differentiation from normal cases of mycosis fungoides. In contrast, mycosis fungoides generally fulfils criteria typical of low-grade malignant lymphomas.

Dihydroergotamine/heparin in the prevention of deep-vein thrombosis after total hip replacement. A controlled, prospective, randomized multicenter trial.

In a randomized, double-blind, placebo-controlled multicenter trial, the efficacy and safety of dihydroergotamine mesylate/heparin sodium as a prophylactic agent for deep-vein thrombosis were evaluated in 148 patients who were forty years old or more and who underwent total hip replacement. The incidence of venographically proved postoperative deep-vein thrombosis was 52 per cent in the placebo group and 25 per cent in the dihydroergotamine mesylate/heparin sodium group (p = 0.002). Proximal thrombi developed in only 5 per cent and extensive thrombi, in only 10 per cent of the patients who received dihydroergotamine mesylate/heparin sodium. In contrast, proximal thrombi and extensive thrombi developed in 19 and 25 per cent, respectively, of the patients in the placebo group (p less than 0.05). Adverse reactions in the two groups did not differ significantly: in the treatment group they consisted primarily of hematoma at the site of injection (9 per cent), hematoma at the wound (5 per cent), and excessive postoperative bleeding, and in the placebo group there was hematoma at the site of injection (3 per cent). It was concluded that the combination agent dihydroergotamine mesylate/heparin sodium was effective and safe prophylaxis against deep-vein thrombosis for the patients who underwent total hip replacement in this study.

Noncardiac surgery in the elderly patient with cardiovascular disease.

The elderly patient with cardiovascular disease who undergoes noncardiac surgery presents a challenge to the medical-surgical team. A high prevalence of cardiac disease necessitates a preoperative in-depth search for the presence of cardiovascular risk factors and their reversal if possible. Aging is associated with an altered physiologic response to the stress of surgery as well as to anesthetic agents and perioperative medications, requiring that the elderly patient often be treated quite differently than the younger surgical patient. This article provides guidelines for the estimation of the risk of cardiac complication due to noncardiac surgery and discusses the identification and management of acute and chronic cardiovascular problems in the perioperative period.

Spatial and temporal variability of blood flow in stimulated dog gastrocnemius muscle.

The distribution of blood flow in skeletal muscle stimulated to rhythmic isotonic contractions was studied by injections of radioactive microspheres into the arterial supply of gastrocnemius muscles (mean weight 88 g) subsequently cut into 0.5 g pieces for determination of radioactivity. The coefficient of variation (CV = SD/mean) of the ratio of simultaneously injected 10 microns and 15 microns microspheres, 0.12, was taken as the inherent scatter of the method. The average spatial distribution inequality of 10-15 microns microspheres corresponded to a CV of 0.45 and the specific local blood flow inhomogeneity to a CV = 0.43 (= square root of 0.45(2) - 0.12(2)), but there were marked differences between muscles. The temporal variability of blood flow in individual muscle pieces was obtained from the comparison of fractional trapping of 4 to 5 differently labeled microspheres injected at intervals of 2 minutes into steadily stimulated muscles. The mean CV for the variations in time was 0.23 and that corrected for methodological scatter, 0.19. There were large differences between muscle pieces within a muscle and between muscles. The presence of considerable spatial and temporal variations of blood flow in exercising muscle during apparent steady state may be important in limiting and/or modulating tissue O2 supply.