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Biomedical subjects

D G Pennington

Publications and source records attributed to D G Pennington.

At least 109 records · Page 6Linked to original sources
PubMed1988

The changing mortality of myocardial revascularization: coronary artery bypass and angioplasty.

The risk factors and outcome for the first 150 consecutive patients undergoing coronary artery bypass grafting (CABG) in 1985 (CABG '85) were compared with those of the first 150 patients undergoing CABG in 1975 (CABG '75) and those of the first 150 patients to have percutaneous transluminal coronary angioplasty (PTCA) in 1985 (PTCA '85). The CABG '85 patients had a significantly higher (p less than 0.05) incidence of known operative risk factors including advanced age, female sex, severity of angina, history of recent infarction, triple-vessel disease, left ventricular dysfunction, and emergency operation than the CABG '75 cohort. The clinical profile of the PTCA '85 patients closely resembled the low-risk profile found in the CABG '75 patients. Overall mortality following CABG more than doubled during the decade studied (3% versus 7%, p = 0.07). This study suggests that the increased mortality associated with CABG in 1985 is due in part to the inclusion of more high-risk patients in the surgical population. In addition, the application of PTCA removes low-risk patients from the surgical candidate pool and adds more patients requiring emergency operations, thereby further contributing to the overall decline in the clinical status of patients referred for operation.

Age Factors↗
PubMed1988

Bridging to cardiac transplantation with pulsatile ventricular assist devices.

As cardiac transplantation becomes more commonplace in the treatment of end-stage heart failure and as suitable donors become less available, an increasing number of patients will require mechanical circulatory assistance to bridge to transplantation. Since 1982, refractory hemodynamic instability requiring placement of pulsatile ventricular assist devices (VADs) has developed in 11 candidates for transplantation aged 24 to 54 years (mean, 39.6 years). A pneumatic Pierce-Donachy pump was used in 9 patients and an electrical Novacor pump in 2. The cause of the cardiomyopathy was ischemic in 6, postpartum in 2, idiopathic in 2, and doxorubicin hydrochloride toxicity in 1. Seven patients required left ventricular support (LVAD); 4 required biventricular mechanical support (BVAD). Duration of support ranged from 8 hours to 91 days with flows ranging from 4.1 to 8.5 L/min (mean, 5.5 L/min). Although hemodynamic stability was achieved in all 11 patients, contraindications to transplantation developed in 5 patients during VAD support (renal failure in 4, sepsis in 3, disseminated intravascular coagulopathy in 1). The remaining 6 patients (4 with an LVAD, 2 with a BVAD) remained good candidates for transplantation despite major complications in 5 (mediastinal bleeding in 3, driveline infection in 3, development of preformed antibodies in 2, small embolic stroke caused by device malfunction in 1). The 3 patients who were supported the longest (24, 75, and 91 days) were ambulatory while awaiting a donor heart. All 6 patients underwent successful transplantation after 8 hours to 91 days (mean, 24 days) of support. Other than one sternal wound infection, there were no major complications after transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗
PubMed1988

Coronary ostial stenosis.

From January 1970 to December 1986, 2.7% (228/8509) of all patients having coronary artery bypass grafting had atherosclerotic coronary ostial stenosis of 50% or more. There were 126 males (55%) and 102 females (45%) with mean ages of 60.2 +/- 9.0 and 59.2 +/- 10.2 years (P = NS), respectively. The left ostium was involved in 176 (77.2%) patients, the right in 41 (18.0%) and both in 11 (4.8%). Isolated ostial stenosis (no associated coronary disease of 50% or more) was present in 38/228 (17%) with females predominating (29/38, 76%). Isolated ostial stenosis occurred more frequently on the right (10/41, 25%) than on the left (18/176, 16%). Associated coronary disease occurred in a single vessel in 42 patients, in two vessels in 72 and in three vessels in 76 resulting in a mean of 2.0 diseased vessels per patient. If patients with isolated ostial stenosis are excluded there were 2.3 diseased arteries per patient. There were 687 grafts performed in these patients, an average of 2.3 grafts per patient. One month surgical mortality was 4.8% (11/228), but has been 2% (2/104) in the last 4 years. Nine of 27 late deaths were noncardiac with a mean follow-up of 49 +/- 44 months. Ostial stenosis is hemodynamically equivalent to left main disease when the left ostium is involved. Symptomatic ostial lesions, whether right or left, require operative therapy.

Adult↗
PubMed1988

Photodynamic therapy for multiple skin cancers.

Photodynamic therapy is a new treatment modality under trial in a number of centers for use in both early and late tumors of the aerodigestive tract, bladder, brain, and skin. The theory behind its application relies on the selective uptake by a tumor bed of a photosensitizing agent such as hematoporphyrin derivative (HPD) and subsequent exposure of the tumor-bearing area to coherent laser light of suitable frequency. Following exposure, necrosis of tumor occurs to a variable degree depending on the amount of sensitizing agent absorbed by the tumor, the wavelength of laser light applied, the depth of penetration of light into the tumor, and the quantum of light energy delivered. Lack of controlled clinical data on the use of photodynamic therapy in multiple cancers of the skin led us to perform a pilot clinical study in patients. The results of this study were poor enough for us to abandon, on ethical grounds, a planned full clinical trial of the modality. The results are presented and possible reasons for failure of the method are discussed.

Basal Cell Carcinoma↗
PubMed1988

Echocardiography-guided endomyocardial biopsy. A 5-year experience.

The number of cardiac transplant procedures performed each year continues to increase and may exceed 1,600 procedures in 1987. In these patients, the diagnosis of rejection is obtained from serial endomyocardial biopsy. The absence of clinical symptoms associated with allograft rejection with cyclosporine therapy has necessitated a predetermined routine biopsy frequency that averages 10-15 biopsies per patient in the first posttransplant year. Traditionally, fluoroscopy has been used to guide the biopsy, but this technique has a number of negative features, including cumulative radiation exposure in the physician and the patient, limited portability, and the limited area of access (intraventricular septum) for biopsy. In contrast, echocardiography provides greater portability and flexibility for location of procedure performance, eliminates radiation exposure, provides important information about cardiac function, and safely allows biopsy of any area of the right ventricle, including the free wall and apex. We performed over 4,700 individual biopsies for evaluation of rejection in 58 patients who underwent orthotopic cardiac transplantation. Fluoroscopy was not required for any of the echocardiography-guided biopsies, and only two complications occurred in 4,700 biopsies. We propose, therefore, that echocardiography is a useful alternative or adjunct to fluoroscopy for guiding endocardial biopsy and is a technique that can be learned easily by anyone now performing biopsies.

Antilymphocyte Serum↗
PubMed1988

Seven years' experience with the Pierce-Donachy ventricular assist device.

Of currently available methods for mechanical circulatory support, the Pierce-Donachy external pneumatic ventricular assist device has proved to be one of the most versatile and effective. Since 1981, 48 patients, aged 15 to 71 years (mean 43.0), with profound cardiogenic shock refractory to conventional therapy with drugs and intra-aortic balloon support, were supported with the Pierce-Donachy ventricular assist device. There were four patient groups. The largest group consisted of 30 patients with cardiogenic shock after cardiac operations. Nine required left ventricular support, six needed right ventricular support plus an intraaortic balloon pump, and 15 had biventricular support. Duration of support ranged from 3 hours to 22 days (mean 3.6 days). Eight of the first 11 patients died in the operating room of bleeding and/or biventricular failure. However, 16 patients, (53%) had improved cardiac function, 15 (50%) were weaned, and 11 (36%) were discharged. Of the last 19 patients, 47% survived. Frequent factors in nonsurvivors were myocardial infarction (75%) and renal failure (90%). Common complications in all patients were bleeding (52%) and infection (27%). The second group consisted of 11 patients with end-stage cardiomyopathy or acute myocardial infarction in whom the Pierce-Donachy ventricular assist device was used as a bridge to transplantation (left ventricular support, four patients; biventricular support, seven patients). Renal failure, infection, or coagulopathy that precluded transplantation developed in five patients. Five patients were supported for 8 hours to 75 days (mean 20.7 days) before undergoing successful transplantation, with one late death (six months) from rejection owing to noncompliance. One has subsequently undergone successful transplantation after 84 days of support. The third group consisted of four patients, aged 40 to 56 years (means 47.2), who had refractory cardiogenic shock after cardiac transplantation caused by pulmonary hypertension (two patients), hyperacute rejection (one patient), or graft failure (one patient). Despite biventricular support in all four (biventricular assist devices, two patients; right ventricular assist device plus intraaortic balloon pump, two patients), all died of infection and/or renal failure after 12 hours to 6 days (mean 3.4 days) of support. The final group consisted of three patients, aged 36 to 51 years (mean 45), with cardiogenic shock caused by acute myocardial infarction. One patient was supported with biventricular assist devices (3.5 days) and two patients were supported with a left ventricular assist device (8.5 and 15 days).(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1988

Effect of perioperative myocardial infarction on survival of postcardiotomy patients supported with ventricular-assist devices.

Ventricular-assist devices (VAD) have increased survival in patients with postcardiotomy shock, but the predictors of success need to be elucidated. We evaluated 45 patients treated with centrifugal (n = 18) or pulsatile (n = 27) VAD for postcardiotomy cardiogenic shock to determine the effect of perioperative myocardial infarction (PMI) on survival. The patients ranged in age from 15 to 72 years (mean age, 55.1 years). VAD support was left ventricular in 29, right ventricular in seven, and biventricular in nine, and the flow-rate range was 1.6-5.2 l/min (mean rate, 3.97 l/min) for 0.2-22 days (mean time, 4.1 days). PMI was determined by analysis of postoperative electrocardiogram (EKG), enzyme levels, or at necropsy. PMI was considered "possible" if there were either EKG or enzyme level changes, and "definite" if there were EKG and enzyme level changes or necropsy evidence. Of the 45 patients, 19 were successfully weaned from ventricular assistance; 12 were discharged (Group 1), and seven died (Group 2); the remaining 26 patients could not be weaned from VAD support (Group 3). In Group 1, one patient had a definite PMI, and three had a possible PMI. Among the 33 nonsurvivors (Groups 2 and 3), 24 patients had PMI by necropsy examination. Definite PMI was much more common in nonsurvivors (72.7%) than in survivors (8.3%) (p less than 0.05). However, Group 2 nonsurvivors were weaned despite PMI in 100% of cases. These data suggest that, although PMI is a strong negative determinant of survival in postcardiotomy patients, it cannot be considered a contraindication because it does not preclude myocardial recovery.

Adolescent↗
PubMed1988

Coronary artery bypass for recent infarction. Predictors of mortality.

The role of coronary artery bypass (CAB) surgery in patients with recent myocardial infarction remains controversial. To more clearly define the operative risks, we reviewed 336 patients who underwent isolated CAB within 30 days of infarction. There were 129 patients with stable or no angina (Group 1), 163 with angina at rest (Group 2), 21 with angina requiring intra-aortic balloon counterpulsation for pain control (Group 3), and 23 with severe postinfarction ischemia or extension complicated by cardiogenic shock (Group 4). There were 26 (7.7%) deaths overall. The mortality was 2.3% in Group 1, 6.1% in Group 2, 9.5% in Group 3, and 47.8% in Group 4. Univariate analysis (Student's t and chi 2 tests) and multivariate analysis (stepwise logistic regression model) were performed on 17 variables: age, gender, clinical Group (1-4), number of diseased vessels, presence of left main artery disease, left ventricular wall-motion score, left ventricular end-diastolic pressure, presence of mitral insufficiency, extent of infarction (subendocardial vs. transmural), interval from infarction to CAB, number of distal anastomoses performed, preoperative hemodynamic status, aortic cross-clamp time, and total cardiopulmonary bypass time. Only advanced age (p = 0.002), left ventricular wall-motion score (p = 0.004), and clinical group (p = 0.048) proved to be independent predictors of mortality by multivariate analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Follow-up of survivors of mechanical circulatory support.

Improvements in mechanical support for profound circulatory collapse have resulted in increasing survival of these critically ill patients. Since 1980, 27 patients aged 3 days to 69 years (mean 34.9 years) who required mechanical circulatory assistance have been followed up after discharge from the hospital. The refractory cardiogenic shock necessitating mechanical support occurred postoperatively in 22 patients (coronary artery bypass in nine, valve replacement in four, correction of congenital heart defects in nine) and with end-stage cardiomyopathy in five. Fourteen patients were supported with a Pierce-Donachy ventricular assist device (left ventricular assist in seven, right ventricular assist in three, both in four); nine were supported with extracorporeal membrane oxygenation, two with a Medtronic centrifugal left ventricular assist pump, one with biventricular Biomedicus pumps, and one with a Novacor left ventricular assist system. The duration of support ranged from 8 hours to 91 days with a mean of 3.5 days in patients supported for postoperative shock. Major complications occurred in 18 patients (67%), including bleeding that necessitated operative exploration in 14, serious infection in five, renal failure in two, and stroke in two. The five patients with cardiomyopathy underwent cardiac transplantation. The remaining 22 patients who had postoperative cardiogenic shock were weaned from support. There have been four late deaths: two cardiac related at 6 months and two of cancer at 46 and 53 months (one patient was in New York Heart Association class I and the other in class II before death). The remaining 23 survivors have been followed up for 3 to 79 months (mean 29 months) and at last examination 17 (74%) were in class I, two (9%) were in class II, three (13%) were in class III, and one (4%) was in class IV. Eight patients are employed full time, three are retired, four attend school, three are in preschool, one is a housewife, and one is unemployed but free of symptoms. Only four patients have significant cardiac disability, and one of these still works. In conclusion, mechanical circulatory assistance allows adequate support to permit satisfactory long-term survival in patients with refractory cardiogenic shock.

Adult↗
PubMed1988

Nursing care of the patient with a pneumatic ventricular assist device.

Recent technologic advances have led to the development of safe and effective mechanical ventricular assist devices for clinical use. Pneumatic assist devices are being used at an increasing rate at a limited number of institutions throughout the country. One of the major factors in influencing survival of these critically ill patients is establishing standards of nursing care. We recently reviewed our experience of 41 patients who received a Pierce-Donachy ventricular assist device to evaluate the effectiveness of nursing care being provided to these patients. This article includes our most recent protocols of nursing care, which have evolved over the past 6 years. Nursing interventions to prevent or treat common complications such as bleeding, renal failure, and infection are discussed.

Assisted Circulation↗
PubMed1987

Coronary artery bypass surgery in patients aged 80 years or older.

Between August 1980 and January 1986, 23 patients aged 80 years or older underwent coronary artery bypass grafting (CABG) operations. These patients had a higher incidence of severe left main coronary artery narrowing (p less than 0.0001), 3-vessel coronary artery disease (p less than 0.05) and moderate to severe left ventricular dysfunction (p less than 0.05) than patients in the Coronary Artery Surgery Study registry older than 65 years. Of 14 patients undergoing elective simple CABG procedures, none died; of 19 elective cases overall, 2 patients died (11%). Three of 4 patients undergoing emergency procedures (75%) and 4 of 6 patients (67%) requiring intraaortic balloon counterpulsation died. Significant complications occurred in 9 of 18 survivors (50%). All operative survivors improved at least 1 New York Heart Association class, with a mean classification improvement of 3.7 to 1.6 (p less than 0.0001); 13 of 16 long-term survivors were in class I or II. Actuarial survival at 1 and 2 years is 94% and 82%, respectively. CABG can be performed electively in octogenarian patients with increased but acceptable mortality and morbidity risks. Functional improvement and long-term survival are excellent.

Aged↗
PubMed1987

Neonatal diaphragmatic hernia. An improving outlook with extracorporeal membrane oxygenation.

In a 15-year period, 89 newborns were treated for congenital diaphragmatic hernia. The patients were divided into three groups, depending on postoperative therapeutic support available: group 1, ventilator therapy only; group 2, ventilator therapy plus pulmonary vasodilators (tolazoline hydrochloride); and group 3, ventilators, tolazoline, and/or extracorporeal membrane oxygenation (ECMO). The three groups were identical for presenting symptoms, signs, and preoperative blood gas determinations. The survival for each group was as follows: group 1, 17 (40%) of 42; group 2, 14 (45%) of 31; and group 3, 12 (75%) of 16. Complications requiring further operations were identical. All survivors in groups 1 and 2 are normal developmentally, while one of five group 3 ECMO survivors has developmental delay and another has long-term ventilator dependence. These data suggest that ECMO, an invasive technique for newborn respiratory failure, improves survival in congenital diaphragmatic hernia.

Combined Modality Therapy↗
PubMed1987

Primary repair of traumatic aortic disruption.

From 1979 to 1985, 22 patients (18 male) underwent repair of acute traumatic rupture of the aorta. Ages ranged from 15 to 75 years (mean, 35 years). All patients sustained deceleration injuries in automobile accidents. The majority had injuries to multiple systems and evidence of mediastinal widening on routine chest roentgenograms. Aortography confirmed transection in the descending thoracic aorta near the ligamentum arteriosum in 20. Primary repair was achieved in 15 patients; it was performed in the last 10 consecutive patients. Seven patients had repair with a prosthetic graft. Survival was 82%. Postoperative morbidity usually was related to associated injuries. Primary repair of aortic transection can be accomplished in most patients without the use of prosthetic material.

Accidents, Traffic↗
PubMed1987

Concomitant valvotomy and subclavian-main pulmonary artery shunt in neonates with pulmonary atresia and intact ventricular septum.

Our current approach to the management of neonates with pulmonary atresia and intact ventricular septum is to perform a transarterial pulmonary valvotomy through a left anterolateral thoracotomy followed by a polytetrafluoroethylene shunt between the left subclavian artery and the pulmonary trunk at the site of the pulmonary arteriotomy. From October, 1983, to December, 1985, 7 consecutive neonates with pulmonary atresia and intact ventricular septum were managed in this fashion. Mean age was 5.1 days (5 patients, less than 48 hours old), and mean weight was 3.3 kg (range, 2.5-4.3 kg). Right ventricular morphology was type I (tripartite) in 4 patients, type II (absent trabecular portion) in 2, and type III (absent trabecular and infundibular portions) in 1. The mean right ventricular to left ventricular peak systolic pressure ratio was 1.5. One patient who initially had valvotomy alone required a left subclavian-pulmonary trunk shunt the next day for hypoxemia. All other patients had a valvotomy and shunt during the same procedure. There were no operative or hospital deaths. Follow-up of 3.5 to 34 months (mean, 17.5 months) confirmed shunt patency in all patients. Three of 4 patients undergoing postoperative catheterization have shown good right ventricular growth; 2 have undergone successful repair at 10 and 23 months. There have been 3 late deaths at 3.5, 4, and 8 months. Two other patients are doing well and are awaiting postoperative catheterization. This procedure permits synchronous valvotomy and shunting without the need for cardiopulmonary bypass in these critically ill neonates.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Vessel Prosthesis↗
PubMed1987

Anomalous origin of the left coronary artery from the pulmonary trunk: repair after diagnostic cross sectional echocardiography.

An infant with anomalous origin of the left coronary artery from the pulmonary trunk presented with congestive cardiomyopathy. Only cross sectional echocardiography gave a definitive diagnosis. The results of cardiac catheterisation and angiography were inconclusive. Surgical repair was performed successfully after the results of cross sectional echocardiography were known.

Coronary Vessel Anomalies↗
PubMed1986

Extracorporeal membrane oxygenation for newborn respiratory failure.

Jugular vein-carotid artery extracorporeal membrane oxygenation (ECMO) was utilized in 22 newborns (16 male and 6 female) 1 to 12 days old with respiratory failure due to meconium aspiration (12 patients), diaphragmatic hernia (4), persistent fetal circulation (3), hyaline membrane disease (2), and Rh incompatibility (1). Prior to ECMO, all patients had alveolar-arterial O2 pressure gradients greater than 580 mm Hg (predicted mortality greater than 90%), weighed more than 1,800 gm, had a gestation period of longer than 35 weeks, and had no cerebral hemorrhage. The duration of ECMO was 41 to 310 hours (mean, 134.5 hours). Nineteen (86%) of the 22 patients survived ECMO. Death was caused by lung disease (2) and cerebral hemorrhage (1). Four other patients died 6 to 40 days after ECMO of pulmonary hypoplasia (1), pneumonia (1), cerebral edema (1), and hepatorenal failure (1). Complications during ECMO were few and easily managed. Fifteen infants (68%) are alive 1 to 18 months after ECMO. Three have neurological deficit (2 severe, 1 mild). Bayley Developmental Examinations in 4 survivors now more than 12 months old are normal. Extracorporeal membrane oxygenation is an aggressive but effective technique of life support in newborns refractory to conventional respiratory management. Potential complications of ECMO mandate strict aseptic technique, constant monitoring, and multidisciplinary patient management.

Female↗
PubMed1986

Clinical temporary ventricular assist. Pathologic findings and their implications in a multi-institutional study of 41 patients.

Forty-one patients, distributed among four centers, had left (33 patients), right (five), or bilateral (three) temporary ventricular assistance with textured (24) or smooth (17) surfaced diaphragm pumps, during an evaluation supported by the National Institutes of Health. Cardiac failure had occurred in 39 postoperative patients (after aorta-coronary bypass [23], valve replacement [four], both [nine], or other [three]), with total cardiopulmonary bypass time mean 306 minutes (range 69 to 600). Two patients had cardiomyopathy. Death of 35 nonsurvivors was due to myocardial necrosis (14), hemorrhage (nine), cerebrovascular accidents (three), infection (three), and other (six). Mean duration of support in all patients was 62 hours. In 16 patients (40%) whose condition improved, cardiac assist duration was mean 127 hours (range 48 to 264), compared with mean 19 hours (range 1 to 120) in 25 who did not. Of 17 patients in whom duration of support exceeded 72 hours, 15 (88%) improved, 11 were weaned, and six survived long term. Tissue examination (in 33 patients) by biopsy at pump implantation or autopsy revealed coagulation or contraction band myocyte necrosis, with or without hemorrhage, in 26 patients; of these, 10 improved and six were long-term survivors. Pump-related complications (two) included pulmonary embolism, most likely related to a cannulation site thrombus, and an aortic cannulation site infection in one patient each. This study suggests that mechanical cardiac assist may be accomplished with a low complication rate; should not necessarily be denied to patients with existing necrosis, because myocardial necrosis does not preclude improvement or survival; and frequently leads to functional myocardial recovery if patients survive early noncardiac complications, often the result of long duration of cardiopulmonary bypass.

Adolescent↗