Empyema thoracis: lack of awareness results in a prolonged clinical course.

OBJECTIVE: To assess the hypothesis that empyema thoracis (ET) is a problem often not optimally treated. Long delays in diagnosis are common, long hospital stays are typical and recovery with surgery is relatively rapid. DESIGN: A chart review. SETTING: The Regina Health District associated hospitals, a tertiary referral centre. PATIENTS: The charts of 34 consecutive patients having primary respiratory tract disease and seen during the 6-year period Apr. 1, 1991, to Mar. 31, 1997, were identified. OUTCOME MEASURES: Patient presentation, time until diagnosis of ET, number of radiologic investigations, microbiologic features, treatment methods, postoperative course and mortality. RESULTS: The mean delay in diagnosis, defined as the time of admission to the time of correct diagnosis, was 44.2 days (range from 0 to 573 days) and the mean delay until thoracic surgery referral was 47.4 days (range from 0 to 578 days). On average each patient underwent CT 10.1 times, had 2.6 percutaneous drainage procedures and 2.0 chest tube insertions. The mean time from the first percutaneous chest drainage to the date of diagnosis was 29.8 days (range from 0 to 564 days). Of the 26 patients who underwent CT, the mean time from the first CT of the chest to the date of diagnosis was 9.5 days (range from 0 to 75 days). Cultures of pleural fluid grew no organisms in 17 patients; in the remaining 17 patients cultures grew 23 different microorganisms. Of 26 patients who were referred for surgical opinion, 18 underwent decortication; 8 were not considered to be surgical candidates. Pathological examination showed 17 cases of inflammatory empyema and 1 case of mesothelioma (unrecognized clinically). The mean length of hospital stay postoperatively was 15.2 days. CONCLUSIONS: Early suspicion of ET facilitates its treatment, resulting in fewer investigations and shorter hospital stays. When percutaneous drainage does not eliminate pleural effusions, empyema must be considered. Recovery from surgical decortication is rapid in comparison with the typical protracted preoperative hospital course.

Medtronic Mosaic porcine bioprosthesis: midterm investigational trial results.

BACKGROUND: The midterm clinical and hemodynamic performance of the Medtronic Mosaic porcine bioprosthesis was evaluated in a regulatory trial. METHODS: In nine Canadian centers, 802 bioprostheses (560 aortic and 242 mitral) were implanted between September 1994 and April 1999 in patients with a mean age of 70 years. RESULTS: Survival for aortic valve replacement at 4 years was 84.4%+/-3.1%. Freedom from valve-related or unexplained death was 95.6%+/-1.9%; structural valve deterioration, 100.0%; reoperation, 96.2%+/-1.7%; major thromboembolism, 96.1%+/-1.8%; and major antithrombotic-related hemorrhage, 96.4%+/-1.7%. Echocardiographic derived mean systolic gradient was 13.4 mm Hg at 4 years with an indexed effective orifice area of 0.7 to 0.8 cm2/m2. A significant decrease in left ventricular mass was shown over time in all valve sizes. Survival for mitral valve replacement at 4 years was 79.2%+/-6.8%. Freedom from valve-related or unexplained death was 96.5%+/-3.4%; structural valve deterioration, 100%; reoperation, 97.0%+/-3.2%; major thromboembolism, 95.7%+/-3.8%; and major antithrombotic-related hemorrhage, 95.0%+/-4.2%. Echocardiographically measured averaged mean diastolic gradient was 4.5 mm Hg. CONCLUSIONS: The Medtronic Mosaic bioprosthesis is safe and effective in both the aortic and mitral positions. The valve has low gradients in both positions and excellent left ventricular mass regression in the patients with aortic valve replacement.

Aortic wall tension as a predictive factor for abdominal aortic aneurysm rupture: improving the selection of patients for abdominal aortic aneurysm repair.

Aortic wall tension was determined in 40 patients to assess its predictive value in abdominal aortic aneurysm (AAA) rupture. A 3-year retrospective analysis of 243 patients with ruptured AAAs and 45 patients with intact AAAs was conducted. The 288 patient sample was limited to the 40 patients with an abdominal CT scan investigation. Aortic wall tension was calculated using blood pressure data and measurements from computerized tomographic (CT) images of 26 patients with intact AAAs and 14 patients with ruptured AAAs in accordance with LaPlace's Law for wall tension: P x R/W, where P = mean arterial pressure (MAP), R = radius of the vessel, and W = wall thickness of the vessel. The wall tension was approximated with the more readily accessible patient parameters of AAA diameter, MAP, height, and weight. This approximation was termed the body mass index (BMI)-pressure approximation for tension (BPAT), which is AAA diameter/BMI x MAP. Data were analyzed using one-sided t-tests, chi-squared tests, and a regression analysis for the relationship between aortic wall tension and the BPAT. AAA wall tension is a significant predictor of pending rupture. BPAT used to approximate the actual tension in the AAA wall is a more sensitive predictor of rupture than aneurysm diameter alone. A prospective study has been initiated to validate these conclusions.

Exercise prescription for patients with pacemakers.

When developing an exercise program for pacemaker patients, basic information about the pacemaker must be understood. Atrial, ventricular, and dual-chamber devices can produce varying exercise responses and impact the exercise prescription. The type of rate adaptive sensor the pacemaker has will affect the nature of heart rate response, and therefore, must be taken into account when prescribing exercise. While rate modulation is used with most chronotropically incompetent patients, individuals with VVI pacemakers will also benefit from regular exercise. Although the value of exercise testing pacemaker-dependent patients for ECG interpretation may be limited, it is useful in determining exercise capacity and ensuring proper pacemaker function. Participation in a supervised exercise training program can greatly enhance the follow-up and management of pacemaker-dependent patients as well as afford them the opportunity to experience the physical and psychologic benefits typically associated with cardiac rehabilitation.

Improvement of limb circulation in peripheral vascular disease using epidural spinal cord stimulation: a prospective study.

Spinal cord stimulation was used in 46 patients for pain associated with lower extremity ischemic vascular disease that was considered to be nonreconstructable. Thirty-nine patients who had a follow-up examination between 2 and 36 months after the procedure form the basis of this report. Thirty (77%) of 39 cases were considered successful. Clinical endpoints indicating failure included amputation, vascular reconstruction, poor pain relief, or hardware malfunction. The transcutaneous partial pressure of oxygen (TcPO2) increased in both target and control feet. In patients with good outcome with a preimplantation TcPO2 of less than 30 mm Hg, TcPO2 increased significantly (p < 0.05). Pulse volume recording improved significantly (p < 0.05) at the thigh, metatarsal, and great toe levels in successfully treated patients. Peak blood flow velocity also showed a significant increase in patients with good outcome (p < 0.05). Patients with a TcPO2 of less than 10 mm Hg following stimulation tended to undergo amputation within the first 3 months. Improvement in pain control, combined with an increase in TcPO2 values that was greater than 10 mm Hg, were significant early predictors of long-term success. An initial increase in peak blood flow velocities (measured in Doppler studies) of greater than 10 mm also signified a good long-term outcome. Spinal cord stimulation appears to be a useful therapeutic modality for controlling pain and improving perfusion in a select group of patients with end-stage ischemic vascular disease considered nonreconstructable. The best results were seen in patients with severe claudication and rest pain without trophic changes in the foot. The mechanism of this beneficial effect is not yet completely understood.

Resuscitation of severe hypothermia by extracorporeal rewarming in a child.

We report a case of accidental severe hypothermia from cold exposure in a 31-month-old girl. The rectal temperature was 14.2 degrees C on presentation, and was accompanied by cardiac arrest. Other ominous laboratory markers for poor prognosis were also present. The child was successfully rewarmed by median sternotomy and full cardiopulmonary bypass. An amputation of one leg was required, but neurologic recovery was full. We emphasize the importance of timely, aggressive management in victims of severe hypothermia because of the tremendous potential for salvage despite catastrophic presentation.

Atenolol for the prevention of arrhythmias following coronary artery bypass grafting.

Seventy patients undergoing aortocoronary bypass grafting were randomized, double-blind, to receive either atenolol or placebo. There were 35 patients in each group. Patients received either atenolol 5 mg intravenously or matching placebo within 3 h of the completion of surgery. A second intravenous dose was administered 24 h following the first and then atenolol 50 mg orally or matching placebo was given for six days. Continuous Holter monitor recordings were obtained for the 24 h immediately preoperatively and continuously for eight days postoperatively. No patient received any antiarrhythmic drug preoperatively. Patients who required pharmacological intervention for the management of postoperative arrhythmias were withdrawn as treatment failures. Holter monitor analysis continued for 24 h following withdrawal of a treatment failure. All patients were analyzed according to the intention-to-treat principle. Both groups were comparable with respect to age, sex, severity of coronary artery disease, left ventricular ejection fraction, preoperative use of beta-blockers, bypass time, aortic cross-clamp time, number of grafts per patient and frequency of preoperative arrhythmias. Arrhythmia analysis was done manually. Supraventricular arrhythmias (atrial tachycardia, atrial fibrillation and atrial flutter) were classified as either mild (less than 0.5 mins, less than 140 beats/min), moderate (0.5 to 30 mins, 140 to 180 beats/min), or severe (longer than 30 mins, more than 180 beats/min). Ventricular arrhythmia analysis was performed with respect to isolated PVCs, couplets, triplets and episodes of nonsustained ventricular tachycardia.(ABSTRACT TRUNCATED AT 250 WORDS)

Elective aortocoronary bypass grafting in the elderly.

Operative mortality, postoperative morbidity and follow up data were analyzed retrospectively from 122 consecutive patients, over 65 years old undergoing elective aortocoronary bypass grafting for symptomatic relief of angina pectoris at the Plains Health Centre, Regina, Saskatchewan, from January 1980 to December 1985. There were two in-hospital deaths (operative mortality 1.6%). Definite perioperative myocardial infarction occurred in 12 patients (9.8%). The 120 survivors were followed for a mean of 32 months. There were three deaths during follow-up, giving a five-year probability of survival of 93%. Twenty-three clinical events (including deaths) occurred during follow-up, giving a five-year probability of event free survival of 72%. Ninety percent of patients say they are pleased with their operation. Seventy-eight percent are currently angina free. These data illustrate the effectiveness of aortocoronary bypass grafting in low risk elderly patients with symptomatic coronary artery disease.

Cardiac valve replacement in the elderly: a review of 320 consecutive cases.

Cardiac valve replacement in 320 consecutive elderly patients (age 65 years and older) was examined retrospectively to determine the results of valvular replacement. From January 1966 to August 1979, 336 valve prostheses (146 mechanical and 190 porcine) were implanted in 320 patients (mean age 68.9 years, range 65-85 years). There were 190 aortic valve replacements (AVR), 116 mitral replacements (MVR) and 16 multiple valve replacements (MR). There were 178 patients ages 65-69 years, 114 patients ages 70-74 years, and 28 patients ages 75 years and older. Twenty (6.3%) had had previous cardiac surgery. Aortocoronary bypass was performed in 59 (18.4%). Twenty-eight patients (8.75%) died in the hospital (AVR 4.7%, MVR 11.4%, MR 37.5%). The mean follow-up was 30.2 months (total 735 patient-years). There were 92 late deaths, or 12.5% per patient year (AVR 11.3%, MVR 14.9%, MR 20.0%). Actuarial survival for all patients at 5 years was 49 +/- 7.6% (AVR 56 +/- 9.7%, MVR 47 +/- 12.5%). Survival at 24 months was 72 +/- 6.3% for ages 65-69 years, 66 +/- 9.2% for ages 70-74 years and 81 +/- 16% for patients 75 years and older. Valve-related complications were infective endocarditis (three mechanical and five porcine), periprosthetic leak (five mechanical and one porcine), valve dysfunction (12 mechanical) and thromboembolism (18 mechanical and seven porcine). At follow-up, 93.2% of surviving patients were in New York Heart Association functional class I or II.

Profundoplasty: expectations and ominous signs.

Computer analysis of angiographic data on 50 limbs in which profundoplasty was performed is reviewed. Patients with profundus stenosis and graftable findings on arteriogrpahy or with an open popliteal artery had favorable results. Four ominous signs are described: open profundus inflow, competing superficial femoral, poor thigh collateral and poor calf visualization. In the presence of one ominous sign, a success rate of 50% can be expected. The presence of two ominous signs is a contraindication for profundoplasty.