PubMed Health⌕ Search

Biomedical subjects

M Riesgo

Publications and source records attributed to M Riesgo.

11 recordsLinked to original sources
PubMed2005

[Aortic coarctation and postcoarctation mycotic aneurysm in a woman 20 weeks pregnant: anesthetic management].

A 28-year-old woman, 20 weeks pregnant, was diagnosed with aortic coarctation and postcoarctation mycotic aneurysm. After anesthetic induction, blood pressure was monitored in the radial artery of the right arm and the femoral artery of the right leg for two purposes: to verify hemodynamic stability as required in this type of operation and to determine the pressure gradient between the upper and lower limbs, which was approximately 40 mm Hg. To prevent spinal cord ischemia, an intradural catheter was inserted into the fourth and fifth lumbar space for spinal fluid drainage. A double lumen tube was used for intubation so that the left lung could be blocked, and a centrifugal pump was used instead of extracorporeal circulation. The aneurysm was resected through a left thoracotomy and an aortic prosthesis was placed. Satisfactory outcome was indicated by resolution of the pressure gradient, and fetal viability was verified by ultrasound. The mother suffered no neurological complications and the pregnancy continued to term uneventfully. We review the anesthetic procedure to follow in such cases.

Adult↗
PubMed2002

[Treatment of postoperative pain in heart surgery].

Postoperative pain ranks among the major problems surgical patients face and it has been taken particularly seriously in recent years. Catecholamine release in response to nociceptive stimulus is associated with higher rates of hemodynamic, respiratory, endocrine, metabolic and immune system complications that worsen the prognosis. Pain after cardiac surgery in the adult has been investigated little, however, probably because it is less intense than pain after thoracotomy. The importance of providing good perioperative analgesia requires us to have an in-depth understanding of the characteristics of such pain, the therapeutic armamentarium available and the technique to be used. Although intravenous analgesia is the most widely applied approach to postoperative pain management, the development of devices for patient controlled analgesia and the advantages of epidural analgesia require us to analyze what the ideal technique might be. The advantages of strict pain control after cardiac surgery oblige us to place greater emphasis on such management among our main postoperative objectives.

Cardiac Surgical Procedures↗
PubMed1998

[Changes in therapeutic attitude based on transesophageal echocardiography in cardiac surgery].

Transesophageal echocardiography is a monitoring system that is changing the practice of cardiovascular anesthesia and surgery by providing real time images of cardiovascular anatomy and pathophysiology. Our hospital's anesthesiology and postoperative intensive care departments, in particular the cardiac anesthesia team, initiated a joint project in June 1993 with the echocardiography laboratory team to incorporate this surgical monitoring system. Here we report the wealth of information we obtained and describe the possibility of modifying a therapeutic approach based on the images visualized, even when conventional monitoring gives contradictory information. Two illustrative case reports are included.

Anesthesia, General↗
PubMed1991

[The midterm (6 years) clinical results of the Carpenter-Edwards supra-annular bioprosthesis].

We present here the clinical results with a second-generation porcine bioprosthesis, the Carpentier-Edwards supra-annular valve (CESA). Two-hundred and twenty-two CESA bioprostheses were implanted in 189 patients during a four-year period (from 1984 to 1987), either as an isolated procedure or associated to mitral or tricuspid repair. The mid-term clinical results have been evaluated after a mean follow-up of 3.4 years, being 96% complete. There were 16 in-hospital deaths (8.4%) and 6 late, potentially valve-related, cardiac deaths (1.1% patients/year). Overall, 86.7 +/- 2% of the patients were free from cardiac death at 6 years (95.1 +/- 2% of the patients surviving the operative period). Linearized rates of valve related complications were the following: 1.4% patients/year for thromboembolism (including valve thrombosis), 0.5% patients/year for treatment-related hemorrhage and 0.7% patients/year for endocarditis. We did not found any case of either intrinsic or extrinsic valve failure, unrelated to infection of thrombosis. Two patients were reoperated, one because of valve thrombosis and the other due to prosthetic valve endocarditis (reoperation rate of 0.3% patients/year). When lethal and nonlethal valve-related complications (including in-hospital deaths) were considered all together, 75.8 +/- 8.4% of the patients remained alive and free of morbid events at 6 years. When patients were grouped according to the valve replaced (aortic, mitral and multiple), best results were found with patients submitted to isolated aortic valve replacement. We conclude that the CESA bioprosthesis has an excellent mid-term clinical performance. However, longer follow-up is necessary to know if improvement in valve design and manufacturing results in increased valve durability.

Aortic Valve↗
PubMed1990

Flow capacity of the human retrograde internal mammary artery: surgical considerations.

The diastolic flow of the retrograde internal mammary artery (IMA) was calculated in 30 patients and compared with the expected coronary flow of the left ventricle and that of specific branches. Arterial pressure and free flow were measured in the proximal and distal IMA as well as in the superior epigastric and musculophrenic arteries. Systolic and mean arterial pressure were significantly higher in the proximal IMA than in any other site, but diastolic pressure was comparable. Overall and diastolic antegrade IMA flows (77 +/- 6 and 44 +/- 3 mL/min) were significantly greater than the retrograde flows through the distal IMA (18.5 +/- 2 and 11.5 +/- 1 mL/min), musculophrenic artery (13.3 +/- 1 and 7.9 +/- 1 mL/min), and superior epigastric artery (5.3 +/- 0.4 and 3.1 +/- 0.2 mL/min). Only patient-size-related variables correlated significantly with retrograde IMA flow. Diastolic retrograde IMA flow represented 8.5% +/- 0.6% of the expected left ventricle coronary flow and in 12 patients (40%) was greater than the expected flow of at least one posteroinferior coronary artery. Based on these data, the retrograde IMA may adequately perfuse the posterior descending or other posterolateral coronary branches in select patients. Previous measuring of the retrograde flow is mandatory.

Adult↗
PubMed1990

[Long-term experience with multivalve replacement with the Medtronic-Hall mechanical prosthesis].

During the period from January to September 1986, 182 Medtronic-Hall (M-H) heart valve prostheses were implanted in 89 patients, mainly because of rheumatic valve disease (68.5%). The patients were divided in two groups. Group I consisted of 83 patients with aortic and mitral valve replacement. Six patients with tricuspid valve replacement plus aortic and/or mitral valve replacement constituted group II. In group I the majority of the patients (86.7%) were in functional class III or IV (NYHA). Twenty three patients had undergone at least one previous cardiac operation. Hospital mortality was 6.02% (5/83). In group II the patients were in functional class III or IV (NYHA). Hospital mortality was 33.3% (2/6). Death occurred in the operating room in only one instance. Follow-up was completed in 98.9% and extended from 27 months to 8 years (348.7 patient years in group I and 23.08 patient years in group II). The overall 5 and 8 years actuarial survival, freedom of thromboembolism and freedom from endocarditis rates in group I were: 80.8 +/- 4.4% and 72.7 +/- 5.2%; 89.8 +/- 4% and 85.8 +/- 4.7%; 94.8 +/- 1.2 and 93.1 +/- 1.7%. In group II, actuarial studies were not carried out because of the scanty number of cases. There were another complications in group I: haemorrhage due to anticoagulation in 6 cases, hemolysis in 8 instances and periprosthetic leaks in 2 cases. There were no cases of structural failure. We conclude that after 8 years of follow-up the M-H valve prosthesis shows an excellent clinical performance and mechanical reliability, and the incidence of valve-related complications was in the low range of that reported with other mechanical prostheses.

Adult↗
PubMed1989

[Myocardial revascularization surgery during a developing infarction].

Our results with surgical revascularization for evolving myocardial infarction in 30 patients are analyzed. There were 25 men and 5 women (mean age 55 +/- 10 years), most with unstable angina (80%), which sustained an acute myocardial infarction secondary to either a severe stenosis (23%) or a complete obstruction (77%) of a mayor coronary artery during a diagnostic coronarography (27%) or a percutaneous transluminal coronary angioplasty (73%). The most frequently involved vessels were the left anterior descending and right coronary arteries (11 cases), followed by the left main stem (5 cases) and the circumflex artery (3 cases). Nineteen patients (group I) developed electrocardiographic and/or enzymatic evidence of established myocardial necrosis despite early reperfusion, whereas 11 patients did not (group II). These groups were compared according to different clinical, angiographic, hemodynamic, and operative variables. Group I patients had a more recent disease and a better segmentary contraction. The same variables were compared between the 5 patients with early cardiac death (group III) and the remainder 25 (group IV). Refractory cardiac arrest, jeopardized myocardial mass and coronary perfusion indexes after the infarction-related complication, all were more desfavorable in group III. The ischemic interval between infarction onset and reperfusion was not different between the groups. The potential of surgery for myocardial salvage in the setting of evolving necrosis is emphasized as well as the influence of the magnitude of involved myocardium and its clinical repercussion on early mortality.

Adult↗
PubMed1987

Myocardial reperfusion in the pig heart model: infarct size and duration of coronary occlusion.

The effect of coronary artery reperfusion on infarct size was studied in a pig heart model. Forty four open chest pigs underwent occlusion of the mid-left anterior descending artery. Fifteen minutes after occlusion the animals were randomised to one of five groups: reperfusion at 30, 45, 60, or 90 min after occlusion (groups 1-4) or permanent occlusion (group 5). Twenty four hours after coronary occlusion the pigs were killed. The heart was sectioned in slices, which were incubated in triphenyl-tetrazolium. Mean(SEM) infarct sizes calculated by planimetry were 0.46(0.42), 2.85(1.14), 9.74(1.65), 8.93(1.37), and 13.17(1.17)% of left ventricular mass in the five groups. The transmural extension of the infarct was 14.6(11.4), 42.1(12.9), 87.4(6.6), 96.2(3.2), and 100(0)% and a transmurality index used as an estimate of the mean extension of the infarct relative to wall thickness was calculated to be 0.08(0.06), 0.32(0.10), 0.72(0.06), 0.79(0.04), and 0.92(0.02) respectively. Infarct size was similar in groups 3-5, but significantly smaller in groups 1 and 2 (p less than 0.05). Infarct size and the transmurality index correlated exponentially with the duration of the occlusion (r = 0.80, p less than 0.01; and r = 0.95, p less than 0.001 respectively). These results indicate that in the pig heart model submitted to an acute coronary occlusion cell viability may be less than that suggested by previous canine studies. This observation is probably related to a less well developed collateral blood flow in the pig heart and may provide an experimental model that better resembles certain clinical conditions.

Acute Disease↗
PubMed1987

Transient occlusion of the left anterior descending coronary artery in pigs.

The purpose of this study was to define a model of transient coronary occlusion (CO) in the open-chest pig. The left anterior descending (LAD) coronary artery was occluded at its mid-length in 45 white pigs and reperfusion was performed after 30, 45, 60 or 90 min. One group of 9 animals with permanent CO served as control. During the occlusion period only slight hemodynamic changes were observed, but a period of ventricular arrhythmias was consistently observed between 15 and 30 min after CO, with an incidence of ventricular fibrillation (VF) in 8 cases (18%). All but 1 of the animals with VF could be defibrillated in less than 1 min or 3 electrical countershocks. Complex arrhythmias with marked hypotension were consistently observed after reperfusion. Histological examination showed a patent coronary artery lumen and minor changes in the LAD coronary artery at the site of occlusion in the reperfused animals and completely occluded arteries in the control group. Two pigs (4.4%) died during the night following CO. Transient CO can be performed safely in pigs with a very low complication rate and a high 24-hour survival rate.

Animals↗