PubMed Health⌕ Search

Biomedical subjects

B J Drew

Publications and source records attributed to B J Drew.

At least 19 recordsLinked to original sources
PubMed1994

Electrocardiographic changes in critically ill adults during intrahospital transport.

Critically ill patients are frequently transported out of the intensive care unit (ICU) for diagnostic tests and procedures. Advanced diagnostic testing and increased patient acuity have influenced the level of nursing care required during intrahospital transport. Previous studies have documented deleterious patient outcomes during intrahospital transport, but none have evaluated twelve lead electrocardiograms (ECGs). Using a prospective design, this study sought to describe ECG changes during intrahospital transport. A secondary purpose was to describe the nursing implications of transporting the patients in this sample. A convenience sample of 29 critical care patients (14 cardiac, 8 neurological, 5 medical, 2 transplant) was selected from three ICUs at a university hospital. In addition to the standard, single bipolar lead monitor, patients were monitored with a portable, interpretative electrocardiograph with continuous 12 lead ST segment analysis. Results of this study indicate that cardiac events during intrahospital transport may go undetected because of current monitoring practices and the mechanics of transport.

Adult↗
PubMed1994

T wave alternans.

Explore the source record for details and available documents.

Electrocardiography↗
PubMed1993

Safety and efficacy of central intravenous bolus administration of adenosine for termination of supraventricular tachycardia.

OBJECTIVES: This study was done to quantify the dosing differences between central and peripheral adenosine administration for treatment of supraventricular tachycardia. BACKGROUND: Earlier studies that evaluated the safety and efficacy of adenosine primarily utilized a peripheral site of administration. Although it has been recommended that lower doses should be given centrally, dosing recommendations have not been provided. METHODS: Thirty adults with supraventricular tachycardia underwent invasive electrophysiologic study and were treated with central and peripheral intravenous administration of adenosine. Peripheral injections were administered through a venous catheter in an upper extremity and central infusions were accomplished by means of a catheter positioned in or near the right atrium. The site of administration was randomized and each subject received adenosine by both routes. Adenosine was administered every minute in increasing increments of 3, 6, 9 and 12 mg until the tachycardia terminated. Peripheral responses were compared with those obtained centrally. RESULTS: The minimal effective peripheral dose was distributed among the four doses: Tachycardia was terminated in 11 patients with 3 mg (37%), in 10 (33%) with 6 mg, in 4 (13%) with 9 mg and in 5 (17%) with 12 mg. In contrast, after central administration, 23 episodes of tachycardia (77%) were terminated with 3 mg, 6 (20%) with 6 mg and 1 (3%) with 9 mg; none required 12 mg. Lower doses of adenosine were more effective after central than after peripheral administration, with 63% of the subjects requiring a lesser dose. There was no difference between the two routes of drug administration in the incidence of side effects or transient arrhythmias at the time of tachycardia termination. CONCLUSIONS: Adenosine can be safely given centrally for termination of supraventricular tachycardia. The initial dose should be 3 mg.

Adenosine↗
PubMed1993

ST segment monitoring for coronary artery reocclusion following thrombolytic therapy and coronary angioplasty: identification of optimal bedside monitoring leads.

BACKGROUND: Bedside ST segment monitors analyze only one precordial lead and one, two or three limb leads. The precordial lead V1 (or V6 if V1 is not feasible) has been recommended for bedside monitoring because of its value in diagnosing cardiac rhythms with a wide QRS complex. Thus, the remaining lead choices for ST monitoring are limited to the six limb leads. PURPOSE: To determine which of the limb leads in conjunction with V1 or V6 provides the greatest sensitivity for myocardial ischemia, a study was undertaken. METHOD: A total of 30 vessel-unique ischemic episodes were analyzed prospectively using continuous 12-lead electrocardiographic recordings in patients with acute myocardial infarction (n = 2) and patients undergoing coronary angioplasty (n = 25). RESULTS: Ischemic changes were evident in all cases using the full 12-lead electrocardiogram. Right coronary artery-related ischemia was detected in all cases using a single-lead III or aVF. In the group as a whole, the best combinations were: V1 + aVF, V1 + III, V6 + III, and V6 + aVF. Two patients developed sudden coronary artery reocclusion in the cardiac care unit after successful angioplasty. In both, leads identified in the cardiac catheterization laboratory as sensitive for recording ischemia were excellent choices for detection of reocclusion in the cardiac care unit. CONCLUSIONS: 12-lead electrocardiogram recordings during coronary angioplasty balloon inflation provide excellent guidance for postprocedure lead selection decisions. The most valuable limb leads for detecting ischemia due to abrupt artery closure are leads III and aVF, either of which is more sensitive than the routinely monitored lead II. The precordial leads valuable for arrhythmia monitoring, V1 and V6, are seldom sensitive in detecting ischemia in these patients.

Adult↗
PubMed1993

Bedside electrocardiogram monitoring.

A recent national survey of critical care nurses reveals that the leads many nurses select to monitor their patients are diagnostically inferior to other available leads, and that lead placement often is inaccurate. This article reviews the best leads for electrocardiographic (ECG) monitoring, illustrates their accurate placement, and explains reasons for the dilemma in current practice. Questions relevant to practicing nurses are addressed, including 1) Is lead MCL1 as good as V1? 2) When is it appropriate to substitute lead MCL1 for V1? and 3) How important is it for electrodes to be placed exactly in specific anatomic locations? Finally, a case study is provided to illustrate how accurate monitoring can prevent misdiagnosis and resultant inappropriate therapy.

Critical Care↗
PubMed1993

ST segment monitoring for myocardial ischemia.

Many patients in the critical care unit (CCU) are at risk for myocardial ischemia and acute coronary artery reocclusion. The use of continuous ST segment monitoring detects transient and sustained ischemia, despite the absence of symptoms, more completely than rate and rhythm monitoring alone. The accuracy and sensitivity of the ST segment for detection of ischemia is dependent on the number and location of the electrocardiographic leads used in conjunction with the site of obstruction. Thus, when using ST segment monitoring for detection of ischemia, one of the most important decisions for the nurse to make is lead selection. In addition, both ischemic and nonischemic ST segment changes must be considered.

Critical Care↗
PubMed1992

Comparison of a vectorcardiographically derived 12-lead electrocardiogram with the conventional electrocardiogram during wide QRS complex tachycardia, and its potential application for continuous bedside monitoring.

Previous investigators published conflicting reports comparing a vectorcardiographically derived electrocardiogram (ECGD) with the conventional 12-lead one (ECG). Prior comparisons were obtained in adults during sinus rhythm, but never in patients with wide QRS complex tachycardia. The ECGD was evaluated during baseline rhythms in patients with varying cardiac diagnoses, and the diagnostic accuracy of the 2 methods was compared during 64 episodes of wide QRS complex tachycardia in 49 patients during cardiac electrophysiologic study. All leads of the 12-lead ECGD closely resembled the conventional ECG in baseline and tachycardia tracings, except leads V3 and V4. QRS voltages were less in the ECGD, resulting in an inability to detect left ventricular hypertrophy in one third of patients with that diagnosis. There was excellent agreement between the ECGD and ECG in diagnosing prior myocardial infarction (92%), ventricular preexcitation patterns (100%), bundle branch and fascicular blocks (100%), and axis deviation. The ECGD was equally as valuable as the ECG in the diagnosis of wide QRS complex tachycardia. There was perfect agreement between the 2 lead systems in application of the morphologic criteria differentiating supraventricular tachycardia with aberration from ventricular tachycardia in leads V1, V2 and V6, and for criteria requiring axis determination and measurement of RS intervals in the precordial leads. The ECGD tracings contained less muscle artifact during body movements (e.g., after direct-current defibrillation). In conclusion, the ECGD's close correlation with the ECG, and its technical superiority and simple 5 torso-positioned electrode configuration make it worth pursuing as an option for continuous bedside monitoring.

Adult↗
PubMed1991

Value of electrocardiographic leads MCL1, MCL6 and other selected leads in the diagnosis of wide QRS complex tachycardia.

To compare the modified precordial leads MCL1 and MCL6 with the conventional precordial leads V1 and V6 and assess the diagnostic accuracy of selected leads for continuous bedside electrocardiographic (ECG) monitoring, 121 wide QRS complex tachycardias were recorded from 92 patients during cardiac electrophysiologic study. As ascertained from intracardiac recordings, 86 tachycardias were ventricular and 35 were supraventricular with aberrant conduction. Early or late peaking of the predominant QRS deflection in lead MCL6 or V6 proved valuable in diagnosing wide complex tachycardia. An interval of less than or equal to 50 ms from the onset of the QRS complex to the predominant peak (or nadir) indicated supraventricular tachycardia; an interval of greater than or equal to 70 ms indicated ventricular tachycardia. The QRS complexes in leads MCL1 and MCL6 were comparable to those in leads V1 and V6 during sinus rhythm. Significant discrepancies in QRS configuration occurred between the modified and conventional precordial leads during ventricular tachycardia, especially between leads MCL1 and V1; however. these differences did not affect diagnostic accuracy. A single MCL1, V1, MCL6 or V6 lead was equally valuable in the diagnosis of wide complex tachycardia and far superior to a single lead II. A combination of leads (MCL1 + MCL6), (V1 + V6), (V1 + I + aVF) or (V1 + V6 + I + aVF) was superior to a single lead or the routinely monitored lead V1 + II combination.

Bundle-Branch Block↗