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Biomedical subjects

R N Garrison

Publications and source records attributed to R N Garrison.

At least 127 records · Page 7Linked to original sources
PubMed1985

Initial experience with a new prosthetic angioaccess device.

Long-term vascular access has increased longevity for many patients with end-stage renal disease. Much of the hospitalization in this group of patients continues to be for maintenance of reliable vascular access. Thrombosis, infection, aneurysm, and stenosis lead to serious morbidity. The Hemasite angioaccess system has been introduced in an attempt to circumvent some of these problems. We reviewed our initial experience with 90 of these devices placed in 77 patients during the past 24 months. Thirty-five devices (39%) were placed under emergency conditions when the primary access site had failed, 34 (38%) were used as the initial access procedure, and simple patient convenience was the indication 21 times (23%). Twelve patients have died, with no deaths related to the device. Twenty-eight infections and 18 thromboses accounted for the failures. Fourteen thromboses were seen with the graftless device where collateral flow existed around it. One-year patency was 46% for all devices, 38% for 34 graftless devices placed in the upper arm, and 50% for the grafted model in the upper arm position. Overall patency is not comparable to other access methods yet patient acceptance is high. Placement in the upper arm offers the highest rate of success.

Actuarial Analysis↗
PubMed1985

Bacterial inoculum and the activity of antimicrobial agents.

Experimental and clinical infections have concentrations of bacteria that are greater than the concentrations used in the laboratory for the determination of in vitro activity. When realistic concentrations are used, the antibiotic activity is reduced. The optimum selection of antibiotics may require a re-examination of the laboratory procedures for the determination of sensitivity data.

Abdomen↗
PubMed1984

Early urgent relaparotomy.

We analyzed the indications for and implications of reoperation in 113 patients who required early urgent relaparotomy. Infection with intact organs was the most common indication, causing the most diagnostic difficulties, and presenting the most varied findings. Suture-line leaks and dehiscence were next in frequency. Bleeding caused the earliest relaparotomies and obstruction, the latest. In seven patients a technical error at the primary laparotomy was identified, and in 56 patients an error of some sort was presumed. High-mortality categories were identified, including the elderly, who were particularly susceptible if bleeding or after an emergency primary laparotomy. An aggressive policy of reoperation resulted in 59 survivors and seems to be the only practical approach in the treatment of these usually desperately ill patients.

Aged↗
PubMed1984

Clarification of risk factors for abdominal operations in patients with hepatic cirrhosis.

Celiotomy in cirrhotic patients is reported to bear a high risk of operative morbidity and mortality. We reviewed 100 consecutive, cirrhotic patients who underwent nonshunt celiotomy. Thirty patients died and major complications occurred in another 30 patients. Hospital mortality rate was 21% in 39 biliary operations, 35% in 26 procedures for peptic ulcer disease, and 55% in nine colectomies . Fifty-two variables were compared between survivors without complication, survivors with complications, and nonsurvivors. A computer-generated, multivariant discriminant analysis yielded an equation predictive of survival. Utilizing coagulation parameters, presence of active infection, and serum albumin, the equation predicted survival with 89% accuracy. In a similar fashion, amount of operative transfusions, absence of postoperative ascites, pulmonary failure, gastrointestinal bleeding, and culture-positive urine predicted survival with 100% accuracy. We conclude that celiotomy in the cirrhotic patient is truly associated with very high morbidity and mortality, and preoperative assessment can predict survival with 89% accuracy.

Abdomen↗
PubMed1984

Splenectomy in hematologic malignancy.

Fifty patients undergoing splenectomy for complications of hematologic malignancy were reviewed to define indications and results. Primary diseases included lymphoma (n = 14), chronic lymphatic leukemia (n = 13), hairy-cell leukemia (n = 12), myeloid metaplasia (n = 6), and other similar disorders (n = 5). Indications for splenectomy in these patients included cytopenia (n = 37), diagnostic laparotomy (n = 8), "small stomach" syndrome (n = 3), and abdominal pain (n = 2). Splenectomy was performed by the midline approach in 32 patients. In 40 patients, the splenic artery was ligated prior to mobilization of the spleen. The spleens averaged 1650 g; in eight patients accessory spleens were removed. Additional surgical procedures included liver biopsy (n = 30), lymph node biopsy (n = 15), and cholecystectomy (n = 3). Intraoperative blood loss averaged 750 ml. In 14 patients, drainage of the left subphrenic space was used. Splenectomy was effective in 36 of 50 patients. In seven patients, splenectomy was ineffective in correction of cytopenia. Seven mortalities were from bleeding (n = 2), pulmonary embolus (n = 2), postoperative sepsis (n = 2), and progression of primary disease (n = 1). Additional complications included reoperation for bleeding (n = 3), septic complications including pneumonia (n = 14), wound infection (n = 4), and intra-abdominal abscess (n = 2). Splenectomy for the patients with hematologic malignancy is generally effective. Meticulous hemostasis, timely administration of intraoperative platelets, surgical asepsis, and aggressive pulmonary care are essential to reduce morbidity and mortality.

Adult↗
PubMed1984

The impact of demographic trends on hospital surgical care.

The projected increase in numbers and percentages of elderly people has great potential impact on health services generally. Only rarely, however, has the impact of age of patients on a surgical service been quantitated. Two hundred fifty-five consecutive laparotomies performed in men older than 65 years of age were compared with 174 consecutive laparotomies in men younger than 65 years of age, all from a Veterans Administration Medical Center experience. Morbid factors, including mortality, increased with age with the greatest increments over the age of 75 years and especially over the age of 85 years. An intensity-of-care index was devised; the intensity-of-care ratios progressively increased with age. Unless there are significant technical advances, future surgical results will not be as good as they are at present, since the patient composition will be less favorable. Any estimates of the costs of surgical care in the future must include the projected age of patients as a major factor.

Abdomen↗
PubMed1983

Endotoxin, cellular function, and nutrient blood flow.

To study the effects of endotoxemia on hepatic mitochondrial function and nutrient blood flow, rats were given intraperitoneal Escherichia coli endotoxin at a lethal dose for 90% mortality of group. Controls received only diluent. Five hours after the onset of endotoxemia, paired experimental and control animals had indocyanine green (ICG) clearance determined as the half-life (t1/2) at low (5 mg/kg) or high (15 mg/kg) doses. Low-dose ICG clearance represented hepatic nutrient blood flow; a Lineweaver-Burke plot of clearance rate v dose of administration provided extrapolation to an infinite dose and served as a sensitive indicator of hepatocellular function. Additional endotoxic rats were killed at five hours, liver and kidney mitochondria were isolated, and isolates were studied by the polarographic technique; the respiratory control index was determined as a sensitive indicator of efficient cellular oxygen metabolism with glutamate and succinate as substrates. Our data indicated that (1) uncoupling of the mitochondrial function is not identified during the early phase of endotoxemia, (2) reduced nutrient blood flow occurs during this early phase of endotoxemia, and (3) subsequent cellular abnormalities in endotoxemia may be secondary to ischemia and not direct cellular injury.

Animals↗
PubMed1983

The effects of hydrogen-ion concentration on the respiratory efficiency of human liver mitochondria.

To examine the effects of hydrogen ion concentrations on the coupled respirations of isolated human liver mitochondria, eight patients underwent incidental liver biopsies during the conduct of abdominal surgery. Mitochondria were studied by the polarographic technique at pH of 5.5, 6.0, 6.5, 7.0, 7.5, and 8.0. Results indicated severe inhibition of nicotinamide adenine dinucleotide (NAD)-linked substrates but succinate oxidations were minimally affected. Sodium succinate was then studied as a possible substrate in the resuscitation of hemorrhagic shock. Rats were subjected to bleeding to an arterial blood pressure of 50 mm Hg for 3 hours or until 25 per cent of shed blood had to be reinfused to maintain blood pressure. Resuscitation consisted of reinfusion of all shed blood plus a volume of one of four crystalloid regimens: Ringers lactate; isotonic sodium succinate; hypertonic sodium chloride (190 mEq/l): or twice-normal, hypertonic sodium chloride (308 mEq/l). Results indicated that those rats resuscitated with sodium succinate did poorer than animals receiving alternate regimens. The failure of succinate to diffuse across the plasma membrane may explain these data. Additional studies with succinate or a chemical analogue seem warranted.

Animals↗
PubMed1983

Gastric bypass: Roux-en-Y gastrojejunostomy from the lesser curvature.

We describe a new technique for the surgical treatment of exogenous morbid obesity. The stomach is partitioned from the angle of His toward the lesser curvature, and a Roux-en-Y proximal jejunal limb drains the proximal gastric pouch, which is 25 to 35 ml in capacity. By use of the enteroanastomosis (EEA) or the intraluminal (ILS) stapling instrument for the gastrojejunostomy from the lesser curvature of the stomach, the functional reliability, vascular integrity, and ease of construction of the stoma have been improved. We performed the gastric bypass operation on 300 consecutive patients, 268 women and 32 men, over a two-year period beginning in June 1979. The patients' average admission weight was 126 kg. Diseases associated with obesity were observed in 57% of the patients, and concomitant operations were performed in 29%. The average weight loss at 6, 12, 18, and 24 months was 37.0, 48.5, 51.5, and 52.0 kg, respectively. Early and late complications occurred in 37 patients (12%), requiring 40 reoperations. Two deaths (0.6%) occurred within the 30 months' of observation.

Adolescent↗
PubMed1983

Role of infection in increased mortality associated with age in laparotomy.

Mortality in patients undergoing laparotomy increases with age of the patient. Concomitantly other morbid perioperative factors also are increased, including number and grade of associated system diseases, preoperative infections, severity of disease, emergency operations, post-operative infectious and noninfectious complications, organ failures, and forced secondary operations. All these and other factors may play a role in mortality but two patterns of death are predominant. Some elderly patients present in shock from blood loss or with overwhelming sepsis and die at operation or shortly thereafter. The majority of others who die have intra-abdominal infections preoperatively or they develop infectious complications and these initiate or perpetuate a train of morbid events that prove fatal after days or weeks of intensive supportive therapy. The inability of elderly patients to avoid or to recover from infection appears to be the most common causative factor in increased mortality with age in laparotomy patients.

Age Factors↗
PubMed1982

Pulmonary infection complicating intra-abdominal sepsis: clinical and experimental observations.

Pulmonary infection complicating intra-abdominal abscess is a major clinical problem. One hundred and forty-three patients with abdominal abscesses were reviewed; 41 had associated pneumonia by strictly defined criteria. The causative organisms for the pneumonia were Pseudomonas (35), Klebsiella (20), and Enterobacter (16), while abdominal infections were caused by Escherichia coli (22), Klebsiella (21), and Enterococcus (18). The temporal and bacteriologic relationship between the abdominal and pulmonary infection suggested that decreased pulmonary host defenses might be operative in the high incidence of pneumonia observed. An experimental model for intra-abdominal abscess was created using cecal ligation in the rat. Animals with an abdominal abscess had a marked depression of their ability to clear E. coli and Pseudomonas aeruginosa that were injected into the airway. Macrophages from infected animals did not differ in quantity or viability when compared with those in control animals. The ability to ingest bacteria appeared to be normal or enhanced in infected animals, but there was a significant decrease in the ability of the macrophage to kill the ingested organisms. Such macrophage defects may be partially responsible for the infected animals' inability to clear bacteria in a normal manner.

Adult↗
PubMed1982

Enterococcal bacteremia: clinical implications and determinants of death.

The pathogenicity of the enterococcus remains controversial despite recognition of this organism in inflammatory exudates. A review of 114 patients with 123 bacteremic events with enterococcus from all hospital services was undertaken. A total of 46% were in the perioperative period. The clinical indications for blood culture varied, but only 19 patients had septic shock at the time. Employing three or more associated diseases as a definition, 71 patients were considered chronically ill. The primary sources of bacteremia were commonly urinary tract (22), soft tissue (17), and intra-abdominal (12). An impressive total of 48 patients had no discernible primary focus of infection. Except for the urinary tract, infections tended to be polymicrobial; 51 patients had associated synchronous or metachronous polymicrobial bacteremias. Antibiotic therapy appropriate for enterococcus did not favorably influence outcome. By chi-square analysis, patients with urinary tract and soft tissue infections had significantly better survival rates than the group as a whole, while patients with intra-abdominal sepsis, polymicrobial bacteremia, or an unknown focus of infection did statistically worse. Enterococcal bacteremia results in a high mortality (54%); its frequent identification with other facultative and anaerobic organisms may indicate that it has a synergistic role; the frequency of unexplained bacteremias stimulates speculation that primary bacteremia from the gastrointestinal tract may be a plausible explanation.

Adult↗
PubMed1982

Catheter-associated septic thrombophlebitis.

The clinical presentation and results of management of septic thrombophlebitis in 35 patients over a seven-year period are reviewed. There were 25 men and ten women; 20 patients were over age 50. At diagnosis, fever was present in 33 patients (94%), and 33 (94%) had local signs of inflammation. Pus was expressed from the infusion site in 25 patients (71%). All patients had plastic catheters, with 95% present longer than 48 hours. Klebsiella-Enterobacter was the dominant organism both at the infusion site and in the blood. All patients had surgical excision of the infected vein, followed in 60% by rapid lysis of fever. Other infections were responsible for persistent fever after total excision. Septic thrombophlebitis is best prevented by strict asepsis in catheter placement and rotation of infusion sites every 48 hours. Total excision of the infected vein remains the treatment of choice.

Adolescent↗
PubMed1982

An experimental model of intraabdominal abscess in the rat.

Suitable small animal models of intraabdominal abscess are not available. We have developed a reliable model of intraabdominal abscess in the rat by fasting the animal overnight, devascularizing and ligating the cecum, and injecting 2.5 X 10(8) Escherichia coli and 2.5 X 10(9) Bacteroides fragilis into the ligated cecum. This model results in 39% coli acute mortalities within 48 hours from acute peritonitis, and abscess in 76% of survivals. Subsequent abscesses are 1.0--1.5 ml in volume and contain 4 X 10(8) E coli/ml of pus and 1.4 X 10(9) B fragilis/ml. This model allows chronic evaluation of sepsis in small animals and provides a convenient means to study the abscess microenvironment.

Abdomen↗