PubMed Health⌕ Search

Biomedical subjects

K S O'Toole

Publications and source records attributed to K S O'Toole.

6 recordsLinked to original sources
PubMed2000

The psychometric and cardiac effects of pseudoephedrine in the hyperbaric environment.

STUDY OBJECTIVES: To examine the psychometric and cardiac effects of pseudoephedrine at 1 and 3 atmospheres (atm) of pressure (0 and 66 feet of sea water, respectively), and to make recommendations about the agent's safety in the diving environment. DESIGN: Double-blind, placebo-controlled, crossover study. SETTING: Monoplace hyperbaric chamber of a university hospital. SUBJECTS: Thirty active divers (mean age 38 yrs). INTERVENTION: A bank of seven tests was used to assess cognitive function during four different simulated dive combinations: placebo-1 atm, placebo3 atm, pseudoephedrine-1 atm, and pseudoephedrine-3 atm. MEASUREMENTS AND MAIN RESULTS: Heart rate and cardiac rhythm were recorded during all dives. Repeated-measures analysis of variance was used to analyze the effects of pseudoephedrine, depth, and drug-depth interaction. No significant, independent effects of pseudoephedrine were seen on any of the seven psychometric test scores (p>0.05), although the drug tended to increase anxiety scores (p=0.092). Depth resulted in a significant increase in anxiety scores (p=0.021) and a significant decrease in verbal fluency test scores (p=0.041); it had no significant effects on the other five psychometric tests (p>0.05). Pseudoephedrine caused a significant increase (p=0.036) in mean heart rate, and depth caused a significant decrease (p=0.013). Neither pseudoephedrine nor depth affected cardiac rhythm. CONCLUSION: Pseudoephedrine does not cause significant alterations in psychometric performance at 3 atm of pressure that might increase the risk of diving. Depth causes significant adverse effects on anxiety levels and semantic memory at 3 atm. Pseudoephedrine and depth have significant but opposite effects on heart rate; although, these effects are unlikely to be clinically significant during diving. It is unlikely that pseudoephedrine adds significant risk to the diver.

Adult↗
PubMed2000

The psychometric and cardiac effects of dimenhydrinate in the hyperbaric environment.

STUDY OBJECTIVES: To examine the psychometric and cardiac effects of dimenhydrinate at 1 and 3 atmospheres (atm) of pressure (0 and 66 feet of sea water, respectively), and to make recommendations about the drug's safety in the diving environment. DESIGN: Double-blind, placebo-controlled, crossover study SETTING: Monoplace hyperbaric chamber of a university hospital. SUBJECTS: Thirty active divers (mean age 38 yrs). INTERVENTIONS: A bank of seven tests was used to assess cognitive function during four different dive combinations: placebo-1 atm, placebo-3 atm, dimenhydrinate-1 atm, and dimenhydrinate-3 atm. MEASUREMENTS AND MAIN RESULTS: Heart rate and cardiac rhythm were recorded during all dives. Repeated-measures multivariate analysis of variance was used to analyze the effects of dimenhydrinate, depth, and drug-depth interaction. Dimenhydrinate resulted in a significant decrease in scores of mental flexibility (trail-making, part B, p<0.05) but had no effect on scores in the six other psychometric tests (p>0.05). It had no effect on mean heart rate (p>0.05), although frequent unifocal ventricular ectopic beats occurred in two subjects after ingestion of the drug. Depth resulted in a significant decrease in verbal memory test scores (p=0.001) and mean heart rate (p<0.001). CONCLUSION: Dimenhydrinate adversely affects mental flexibility. This effect, when added to the adverse effect of depth on memory, may contribute to the dangers of diving.

Aged↗
PubMed1990

Intravenous verapamil in the prehospital treatment of paroxysmal supraventricular tachycardia.

The prehospital treatment of paroxysmal supraventricular tachycardia (PSVT) with verapamil alone or in comparison with other interventions has not been studied. A sequential protocol consisting of Valsalva maneuver, ice packs, pneumatic antishock garment inflation, and verapamil 0.5 mg IV was implemented in an urban emergency medical services system after appropriate paramedic education. On-line physician discretion could alter the protocol in specific clinical situations. Inclusion criteria required a narrow-complex regular tachycardia at a rate of between 150 and 250. Of 43 patients identified, the protocol was applied sequentially in 26 (60%) and with valid physician discretion in 15 patients (35%) (due to hypotension, chest pain, or dyspnea). Conversion to a more stable rhythm occurred in 25 patients (59%). Of these, all but one achieved a sinus mechanism. The Valsalva maneuver and ice pack application were ineffective in achieving rhythm conversion, being successful in only two of 33 (6%), one of 31 (3%), and four of 24 (17%) attempts, respectively (P greater than .05). Verapamil, however, was significantly more effective (18 of 24 attempts, 75%) than any of the other interventions either singly (P less than .01) or in combination (P less than .0001). No clinically important adverse effects occurred with any intervention, but application of the protocol increased mean on-scene time to 30.6 minutes. We conclude that verapamil is an effective agent for the prehospital termination of PSVT but that careful on-line physician supervision and a system for confirming rhythm identification are both essential.

Adolescent↗
PubMedDate not supplied

Emergency transcutaneous pacing in the management of patients with bradyasystolic rhythms.

Survival rates in cases of bradyasystolic cardiac arrest are uniformly low, being reported at from 0% to 3%. Recent advances in technology and microcircuitry have produced lightweight, portable external pacing devices that are less painful to the patient. In an on-going clinical trial of early transcutaneous pacing, five cases were seen in which transcutaneous pacing was begun at the onset of the patients' rhythm disturbance. All five patients survived to leave the hospital. Three of the patients were treated in the prehospital setting. Because of the rapidity with which pacing can be implemented, the ease of application and simplicity of operation, transcutaneous pacing has several advantages over the placing of transvenous pacemakers in the field or emergency department setting. In hemodynamically-compromising bradydysrhythmias unresponsive to pharmacologic intervention, the early use of transcutaneous pacing may improve survival in a group of patients who might otherwise die.

Aged↗