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Biomedical subjects

R C Read

Publications and source records attributed to R C Read.

At least 109 records · Page 6Linked to original sources
PubMed1985

Cardiovascular effects of protamine sulfate are dependent on the presence and type of circulating heparin.

Man's response to clinical doses of protamine is highly variable. We investigated the influence of circulating heparin in nine swine (mean age 6 weeks, weight 10 kg). Through a sternotomy we implanted an electromagnetic flow probe around the pulmonary artery for cardiac output determination and catheters into the ascending aorta, pulmonary artery, right atrium, and left atrium for pressure monitoring. Each animal was allowed to recover and was studied awake on 3 consecutive days. Protamine, 3 mg/kg, beef lung heparin, 300 U/kg, and pork mucosal heparin, 300 U/kg, followed by protamine, were given in rotation by intravenous bolus. Protamine alone had no effect. Beef lung heparin followed by protamine induced a marked increase in pulmonary artery pressure (mean 38 +/- 3 to 51 +/- 5 mm Hg in 3 minutes). Pulmonary vascular resistance doubled (mean 0.12 +/- 0.01 to 0.23 +/- 0.04 R within 4 minutes), returning to normal within 15 minutes. Cardiac index and aortic pressure changed minimally. Pork mucosal heparin followed by protamine induced a similar but greater increase in mean pulmonary arterial pressure; however, cardiac index fell significantly (p less than 0.05, 207 +/- 16 to 117 +/- 16 ml/kg/min-1 at 1 minute) despite a regular rhythm and adequate left atrial filling pressure. Thus cardiac contractility was depressed. Systemic hypotension occurred in three of nine pigs. Both mean pulmonary vascular resistance and systemic vascular resistance increased (0.12 +/- 0.01 to 0.67 +/- 0.25 R and 0.40 +/- 0.04 to 1.09 +/- 0.25 R, respectively), significantly (p less than 0.05) more with pork than beef heparin. These data demonstrate that cardiovascular response to protamine neutralization varies significantly in regard to the type of heparin used. Furthermore, circulating heparin is required to produce those effects previously attributed to protamine alone.

Animals↗
PubMed1984

Abdominal aortic aneurysm, Leriche's syndrome, inguinal herniation, and smoking.

We previously found an increase in serum proteolytic activity in smokers with direct inguinal herniation and a similar imbalance in smokers with abdominal aortic aneurysm (AAA), but not in smokers with Leriche's syndrome (LS). If the protease imbalance in the blood of smokers with AAA or herniation is a causal factor, these conditions should be associated. Therefore, we determined whether this is true using patients with LS as control subjects. The frequency of inguinal herniation was significantly higher in the AAA population (N = 341; 25.8%) than in patients with LS (N = 417; 14.6%). In addition, patients with AAA had more severe herniation (direct, bilateral, recurrent, or earlier onset) and had more pronounced leukocytosis (9,000/cu mm v 8,190/cu mm). These data suggest that increased blood proteolytic activity may play a role in the development of both AAA and adult inguinal herniation but not LS. Men who smoke manifest different systemic effects.

Aged↗
PubMed1984

Presidential address. Systemic effects of smoking.

Millions of people continue to smoke. Recent studies confirm the pioneering epidemiologic data that indicated that, despite the well-established effects on the lung, most of the hundreds of thousands of premature deaths annually result from extrapulmonary toxicity, particularly accelerated cardiac and vascular disease. As with lung cancer, abstention significantly reduces the risk, even after myocardial infarction or surgery for complications of vascular disease. Erythrocytosis, thrombocytosis, and leukocytosis, by increasing blood viscosity, aggravate ischemia. The neutrophils of smokers release excessive amounts of oxidants which damage tissue and antiproteases. Increased alveolar permeability enhances allergy. Lymphocytic suppressor cells increase, which leads to immunocompetence, increased infection, and cancer. Smokers lose weight and die at an earlier age, even after cancer chemotherapy and peptic ulcer surgery. Smoking prevents inhibition of gastric night acid secretion by histamine-blocking agents. Menopause occurs earlier and children are damaged in utero and after birth by passive smoking. Recent evidence indicates that nicotine releases endorphins, which account for the addiction. Surgeons need to do more to combat this menace. Many victims need professional assistance to stop the habit.

Aging↗
PubMed1984

The development of inguinal herniorrhaphy.

The history of inguinal herniorrhaphy can be divided into pre- and post- Listerian eras. In this article Bassini's contribution is emphasized along with the preperitoneal approach, the saccular and acquired etiology of herniation, and the use of prostheses or relaxing incisions.

Europe↗
PubMed1983

Efficacy of oral and systemic antibiotic prophylaxis in colorectal operations.

A cooperative Veterans Administration study of the septic complication rate during large-bowel surgery was undertaken in two groups of patients. The first group received oral neomycin and erythromycin base plus parenteral placebo; the second, the oral antibiotics plus parenteral cephalothin sodium. During a five-year period, 1,128 patients were studied. The overall septic complication rate was 7.8% in patients receiving only oral antibiotics, and 5.7% in patients receiving both oral and parenteral antibiotics. This difference was not significant. The only significant finding was a greater incidence of fever of unknown origin in patients receiving only oral antibiotics. None of those patients were treated with additional antibiotics, and all fevers cleared spontaneously. There seems to be no discernible benefit from adding parenteral antibiotic prophylaxis when performing elective colon surgery if appropriate mechanical cleansing and oral neomycin and erythromycin therapy are employed.

Administration, Oral↗
PubMed1983

Fifteen years surgical experience with carcinoma of the lung.

This review has emphasized the need to manage carcinoma of the lung with a systematic approach. Diagnostic and staging procedures should be performed to prevent unnecessary thoracotomy. In patients with limited pulmonary reserve, segmentectomy or wedge resection is an acceptable procedure. A staging mediastinal node dissection should be included in every resection for lung cancer. Those patients with positive mediastinal nodes found in this manner should receive postoperative mediastinal irradiation.

Adenocarcinoma↗
PubMed1983

Serum proteolytic and antiproteolytic activity in acute pancreatitis.

This study has demonstrated an imbalance between the blood proteolytic and antiproteolytic system in acute pancreatitis. Serum elastase activity is markedly increased and elastase inhibitory capacity is decreased in this disease as compared with those in chronic pancreatitis and the control values. We have found that a return to normal values represents better evidence of resolution than amylase determinations. These results offer the clinician a biochemical guideline for the medical management of acute pancreatitis.

Acute Disease↗
PubMed1983

A randomized study of beef lung and pork mucosal heparin in cardiac surgery.

Beef lung heparin had substantially greater anticoagulant activity than pork mucosal heparin during a preoperative heparin tolerance test and also during cardiopulmonary bypass (CPB) in 100 randomized patients. Supplemental heparin was needed during CPB in many more of the patients receiving pork mucosal heparin. Heparin rebound was detected in 16 patients; this low incidence may result from a relatively high protamine:heparin ratio. There was notably less postoperative bleeding in those who received beef lung heparin. Platelet counts were not altered by either type of heparin. It is surprising that the preoperative tolerance curve only predicted heparin sensitivity during CPB in one-half of the patients. Blood activated coagulation time levels were increased markedly by hemodilution and further raised by hypothermia. These data demonstrate that beef lung heparin is better than pork mucosal heparin for CPB.

Animals↗
PubMed1983

Nuclear cardiac ejection fraction and cardiac index in abdominal aortic surgery.

Since atherosclerotic heart disease results in more than half of the perioperative deaths that follow abdominal aortic surgery, a prospective protocol was designed for preoperative evaluation and intraoperative hemodynamic monitoring. Twenty men who were prepared to undergo elective operation for aortoiliac occlusive disease (12 patients) and abdominal aortic aneurysm (eight patients) were evaluated with a cardiac scan and right heart catheterization. The night prior to operation, each patient received volume loading with crystalloid based upon ventricular performance curves. At the time of the operation, all patients were anesthetized with narcotics and nitrous oxide, and hemodynamic parameters were recorded throughout the operation. Aortic crossclamping resulted in a marked depression in CI in all patients. CI remained depressed P less than 0.05 after unclamping in the majority of patients. There were two perioperative deaths, both from myocardial infarction or failure. Both patients had ejection fractions less than 30% and initial CIs less than 2 L/M2, while the survivors' mean ejection fraction was 63% +/- 1 and their mean CI was 3.2 L/M2 +/- 0.6. We conclude that preoperative evaluation of ejection fraction can select those patients at a high risk of cardiac death from abdominal aortic operation. These patients should receive intensive preoperative monitoring with enhancement of ventricular performance.

Aorta, Abdominal↗
PubMed1982

The complicated septic abdominal wound.

Since 1975, we have treated 21 patients with severe postoperative liquefaction fascial necrosis of the abdominal wall (group A, 13 patients), postoperative fascial necrosis with an associated intestinal fistula(e) within the wound (group B, three patients) and postoperative fascial necrosis with multiple internal bowel fistulae causing continuing peritoneal contamination (group C, five patients). Management in group A included general exploratory laparatomy, drainage of intra-abdominal abscesses, debridement of necrotic fascia, and loose closure of the wound with polyethylene (Marlex) mesh. Treatment in group B consisted of suture closure of exposed bowel fistulae with skin flap coverage. Group C was treated with diverting jejunostomy and suture closure of distal fistulae to avoid hazardous dissection and preserve bowel length. Overall survival was 71%.

Abdominal Muscles↗
PubMed1982

Abdominal aneurysmectomy following previous peritonitis.

Repair of abdominal aortic aneurysms in two patients (one emergency and one elective) several months after a bout of peritonitis resulted in graft sepsis. Bacteria cultured from the episodes of peritonitis and from graft sepsis were identical. Repair in elective cases should probably be postponed for at least one year. In urgent or emergency cases, especially when any contamination is encountered, ligation of the aorta and extra-anatomic bypass grafts should be performed.

Aged↗
PubMed1982

Age and morbidity of vagotomy with antrectomy or pyloroplasty.

Seven hundred ninety-three vagotomies with either pyloroplasty (645 patients) or antrectomy (148 patients) were reviewed between 1970 and 1981. Mortality was lowest with elective pyloroplasty (0.4 percent) followed by elective antrectomy (0.7 percent), and emergency pyloroplasty (5.1 percent). The risk of death was significantly higher (p less than 0.05) for the older half of the population (older than 55 years of age). Major morbidity was lowest after elective pyloroplasty (6.3 percent) when compared with elective antrectomy (10.6 percent), and greatest after emergency pyloroplasty (18.1 percent). Proved ulcer recurrence was most frequently seen after pyloroplasty (4.5 percent) and least frequently seen after antrectomy of age) had a significantly decreased risk of ulcer recurrence (p less than 0.001). Disabling sequelae occurred in 3.6 percent of those who underwent pyloroplasty, in 5.6 percent of those who underwent antrectomy with Billroth I reconstruction, and in 8.5 percent of those who underwent antrectomy with Billroth II reconstruction. Significantly more patients who underwent antrectomy with Billroth II reconstruction required reoperation (p less than 0.01) than did those who underwent either pyloroplasty or antrectomy with Billroth I reconstruction. Although antrectomy has become a popular operation, vagotomy combined with pyloroplasty is still the procedure of choice in patients over the age of 55 years. In those requiring emergency operations for duodenal ulcer, and in those in whom antrectomy is technically difficult because of a badly scarred duodenum. Billroth II reconstruction should be avoided after vagotomy and antrectomy.

Adolescent↗
PubMed1982

Blood elastolytic activity in patients with aortic aneurysm.

The question of why obstruction of the aorta (Leriche's syndrome) develops in some patients with severe atherosclerosis of the abdominal aorta while an abdominal aortic aneurysm occurs in others was examined. Significant differences in age, height, weight, mortality, and subsequent operative treatment were found between 335 patients with Leriche's syndrome and 103 patients with abdominal aortic aneurysm. Almost all in both groups smoked and demonstrated leukocytosis. In smokers with aneurysm, circulating serum elastolytic activity and leukocytic granular elastolytic activity were significantly increased, whereas serum antiproteolytic capacity was reduced. These results indicate that the development of abdominal aortic aneurysm in patients who smoke correlates with an abnormal homeostasis between proteolytic and antiproteolytic activity.

Adult↗
PubMed1982

Extended and limited types of Barrett's esophagus in the adult.

Columnar epithelium-lined lower esophagus (CLLE) or Barrett's esophagus was found in 34 patients diagnosed by endoscopic biopsy. In one-half of them, the CLLE extended up to 30 cm from the incisors (limited group) and in the other half, it reached above this level (extended group). Eight patients with stricture and limited CLLE had the lesion in the lower third of the esophagus, whereas 6 of 8 with strictures in the extended group had narrowing in the upper third of the esophagus. Two other patients with extended CLLE were seen with bleeding from Barrett's ulcer, 3 had adenocarcinoma, and the remaining 4 had CLLE without these complications. The three classic histologic types were encountered in both groups. However, in the extended group there was more of the intestinal type and less of the junctional type of epithelium, the latter being seen mostly in the limited group. The extended group had very low lower esophageal sphincter (LES) pressures (mean, 7.3 mm Hg) with severe reflux. The limited group had a higher mean LES pressure (11.2 mm Hg) with less severe reflux. In both groups, LES pressure and reflux improved following effective antireflux operation; some patients who continued to have demonstrable reflux and a lack of improvement in LES pressure despite antireflux operation, the disease progressed, as evidenced by extension of CLLE.

Adenocarcinoma↗
PubMed1982

Changes in arterial oxygenation and pulmonary shunt during thoracotomy with endobronchial anesthesia.

Eight-five veterans underwent thoracic operations, mainly for carcinoma of the lung, with the aid of endobronchial anesthesia. Changes in arterial oxygenation (PaO2) and pulmonary shunt (Qs/Qt) were determined sequentially. Mean PaO2 after both lungs were ventilated for 20 minutes, supine, with 100% oxygen was 433 +/- 8 mm Hg. Selective ventilation of one bronchus dropped this value significantly (p less than 0.01) to 247 +/- 13 mm Hg. PaO2 did not change appreciably when the patient was turned to the lateral position; however, following pleurotomy there was a significant (p less than 0.01) decline in mean PaO2 to a nadir of 178 +/- 17 mm Hg at 90 minutes. Transient hypoxemia (PaO2 less than 60 mm Hg) occurred in 11 of 85 patients, most frequently (7/11) during positioning. Preoperative PaO2 PaCO2, forced expiratory volume in 1 second, forced vital capacity, or medical status did not predict hypoxemia. Qs/Qt increased significantly (p less than 0.01) at the onset of atelectasis from 18% +/- 0.9% to 25.4% +/- 0.9% but did not change with turning. The maximal mean Qs/Qt (30.3% +/- 1.1%) occurred immediately after opening the pleura and then decreased significantly (p less than 0.05), despite the fall in PaO2. Blood loss greater than 1,000 cc (n = 10), especially with hypotension, resulted in a significant increase (p less than 0.05) in Qs/Qt and a fall in PaO2. Thus pulmonary vascular adaptation to acute atelectasis has been demonstrated in man, and this, as in animal models, fails with hemorrhage.

Anesthesia, Endotracheal↗
PubMed1981

Influence of a relaxing incision on suture tension in Bassini's and McVay's repairs.

Suture tension levels measured during 151 inguinal herniorrhaphies in 135 men were higher initially and after a standard relaxing incision in 78 McVay's as compared with 73 Bassini's repairs. The difference, as well as the effect of the relaxing incision on tension, was greater in the middle. In 77 indirect repairs, before relaxation suture tension differed in 51 Bassini's and 26 McVay's procedures only in the midzone. However, with a relaxing incision, the former had much less tension. Similar results were obtained in 74 direct hernias, but better relaxation was seen in 52 McVay's repairs than with their indirect counterparts. These findings were confirmed when 42 McVay's and 37 Bassini's operations on equally (moderate) sized defects were compared. Thus, the complete repair (McVay's operation), with closure of the femoral canal and a deeper, more posterior suturing than in Bassini's operation, is associated with more tension. Use of a relaxing incision is obviously indicated. Further follow-up of our cases may substantiate that the level of suture tension at the time of operation correlates with the risk of recurrence.

Hernia, Inguinal↗
PubMed1981

Arterial embolectomy in the leg. Results in a referral hospital.

The clinical characteristics and course of 90 patients in whom 121 arterial emboli occurred from 1968 to 1978 were reviewed. The factor that correlated most significantly with a favorable outcome was the interval from onset of symptoms until arterial embolectomy was performed. The results of embolectomy were excellent in the patients operated on within 6 hours of symptoms (amputation rate 4 percent, mortality rate 15 percent), but less favorable in the patients operated on within 6 to 12 hours of onset of symptoms (amputation rate 27 percent, mortality 40 percent). Mortality (48 percent) and amputation (52 percent) rates in the patients operated on 12 to 48 hours after onset of symptoms were excessive. It is recommended that immediate embolectomy be performed in all potentially viable extremities in patients who present within 12 hours of symptoms, but that after 12 hours only those limbs with obvious viability (not paralyzed or anesthetic) should be operated on. Alternatives for the remainder are high dose intravenous heparinization or expedient amputation. In patients who present greater than 60 hours after the onset of symptoms, embolectomy can be performed with low morbidity and mortality.

Amputation, Surgical↗