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Biomedical subjects

Jacquelyn A Quin

Publications and source records attributed to Jacquelyn A Quin.

6 recordsLinked to original sources
PubMed2004

The efficacy of supplemental magnesium in reducing atrial fibrillation after coronary artery bypass grafting.

BACKGROUND: Atrial fibrillation after coronary artery bypass is reported from 17% to 53%. Hypomagnesemia after this surgery is considered a contributing factor. METHODS: Two hundred-two coronary bypass patients were randomized to magnesium (n = 105) or placebo (n = 97). The experimental group received 80-mg magnesium sulfate per kilogram ideal weight in 100 mL dextrose 5% water 30 minutes preoperatively. Postoperatively, patients received 8-mg magnesium sulfate per kilogram ideal weight intravenous per hour more than 48 hours. The control group received dextrose 5% water at these intervals. RESULTS: After the first bolus serum magnesium was experimental 4.75 mg/dL versus control 1.91 mg/dL, p less than 0.001, and remained different until postoperative day 4 (experimental 2.33 mg/dL vs control 2.26 mg/dL, p = 0.24). Atrial appendage and strap muscle were analyzed after the first bolus and after revascularization. There were no differences between groups in tissue magnesium or calcium. Urinary magnesium was elevated in the experimental (experimental 324.5 mg/24 hours, vs control 45.1 mg/24 hours, p = 0.01). Calcium excretion was higher (experimental 370 mg/24 hours vs control 186 mg/24 hours, p < 0.001) and was associated with lower serum calcium. Serum calcium was higher in the control through the fourth postoperative day. The incidence of atrial fibrillation was experimental 32 of 105 (30.5%) versus control 41 of 97 (42.3%) p = 0.08. Atrial fibrillation was different on the first postoperative day (experimental 3/105, 2.9% vs control 9/97, 9.3%), p = 0.05. CONCLUSIONS: Overall prophylactic magnesium supplementation does not significantly reduce atrial and ventricular arrhythmias. The only significant benefit of magnesium supplementation was on the first postoperative day.

Atrial Fibrillation↗
PubMed2002

Long-term follow-up of pacing of the conditioned diaphragm in quadriplegia.

The authors have previously shown that conditioning of the diaphragm for continuous bilateral pacing is a feasible and effective means of ventilation in patients with complete respiratory paralysis from high cervical (above C3) quadriplegia. The present study reports the long-term results of continuous diaphragmatic pacing. Twelve quadriplegia patients underwent bilateral phrenic nerve pacemaker placement and diaphragm conditioning from 1981 to 1987. Pacing was initiated at 11 Hz and progressively decreased to 7.1 Hz. A pulse train duration of 1.3 seconds for adults and 0.9 seconds for children was used. Long-term follow-up information obtained included pacing status (full-time, part-time, or mechanical ventilation), ventilation parameters, and social circumstances. Of the 12 patients, 6 continued to pace full time (mean 14.8 years); all were living at home. Three patients paced for an average of 1.8 years before stopping; two were institutionalized. One patient who paced full time for 6.5 years before lapsing to part time, lived at home. Two patients were deceased; one paced continuously for 10 years before his demise, the other stopped pacing after 1 year. Patients who stopped full-time pacing did so mainly for reasons of inadequate social or financial support or associated medical problems. All patients demonstrated normal tidal volumes and arterial blood gases while pacing full time. Despite theoretical concerns about long-term nerve damage, no patient lost the ability to pace the phrenic nerve. Threshold currents did not increase over time (original/follow-up: 0.46/0.47 for right, 0.45/0.46 for left), nor did maximal currents (original/follow-up: 1.16/1.14 for right, 1.37/1.26 for left). This follow-up confirms that quadriplegic patients are able to meet long-term, full-time ventilation requirements using phrenic nerve stimulation of the conditioned diaphragm. Careful review of diaphragmatic pacing candidates with respect to associated medical conditions, social support, and motivation is essential for appropriate patient selection and successful long-term results.

Adolescent↗
PubMed2002

Predictors of pericardial effusion after orthotopic heart transplantation.

OBJECTIVES: Pericardial effusion occurs frequently after orthotopic heart transplantation, but the causes of this complication have not been well described. This study was designed to identify factors predisposing toward the development of significant postoperative pericardial effusions in a large, single-institution population of orthotopic heart transplant recipients. METHODS: A retrospective review of more than 90 preoperative, intraoperative, and postoperative variables was conducted for 241 patients undergoing orthotopic heart transplantation from September 1988 to December 1999. Patients who had significant postoperative pericardial effusions develop were identified from postoperative echocardiograms by standard criteria. Factors associated with the development of significant pericardial effusions were determined by multivariate logistic regression analysis. RESULTS: Echocardiographic data were available for 203 of 241 transplant recipients. Forty-two patients (21%) had significant effusions develop. According to multivariate analysis, pericardial effusions were less likely to occur in recipients with a history of previous cardiac surgery (odds ratio 0.13, 95% confidence interval 0.05-0.36, P <.0001) and with greater weight (odds ratio 0.96, 95% confidence interval 0.94-0.99, P <.0048). Pericardial effusions were more likely to occur in patients who had received aminocaproic acid during the operation (odds ratio 5.92, 95% confidence interval 2.23-15.72, P <.0008). Patient survival and hospital length of stay did not differ between patients with and without postoperative pericardial effusions. CONCLUSIONS: Postoperative pericardial effusions develop in approximately 20% of patients undergoing orthotopic cardiac transplantation. On the basis of the risk factors identified in this study, prevention may prove difficult, although avoidance of the intraoperative use of aminocaproic acid may be helpful.

Aminocaproates↗