Prophylaxis of Venous Thromboembolism in Bariatric Patients.
Explore the source record for details and available documents.
Journal Article↗
Biomedical subjects
AM Macgregor
Publications and source records attributed to AM Macgregor.
The Influence of Dumping on Weight Loss After Gastric Restrictive Surgery for Morbid Obesity.
BACKGROUND: The dumping syndrome that follows Roux-en-Y gastric bypass for morbid obesity is considered to, be the primary mechanism of improved weight loss as compared with the purely restrictive vertical banded gastroplasty. To evaluate the influence of dumping on post-operative weight loss, severity of dumping was determined using Sigstad's clinical diagnostic index. METHODS: One hundred and thirty seven gastric bypass and 19 gastroplasty patients were assessed 18-24 months following surgery. Sigstad's criteria for the dumping syndrome were met by 75.9% of gastric bypass and no gastroplasty patients. Among gastric bypass patients, no relationships were found between severity of dumping and weight loss, as measured by per cent of excess body weight loss or change in body mass index. Weight loss was significantly greater with gastric bypass than gastroplasty patients (72.5 compared to 47.9% of excess body weight loss). All gastroplasty and 24.1% of gastric bypass patients were classified as non-dumpers. The difference in weight loss between surgical procedures was not related to dumping: gastric bypass non-dumpers lost significantly more weight (69.1% excess body weight loss) than gastroplasty patients. CONCLUSIONS: This study fails to demonstrate a significant relationship between dumping severity and weight loss. It is inferred that the superior weight loss of gastric bypass compared to gastroplasty has some other etiology.
Journal Article↗
The Patient Factor.
Long-term results of bariatric surgery are reviewed. The weight criteria for patient acceptance for bariatric surgery and their variation are presented graphically and discussed. Factors affecting patient selection in an attempt to improve outcome results in the small group of patients who currently achieve less weight loss than anticipated are defined. An attempt is made to define pre-operative criteria for selection of pure restrictive versus combined restrictive and malabsorptive procedures. Aspects of motivation, co-morbidity, age and pre-operative weight are discussed and the position statement of the ASBS in regard to laparoscopic bariatric surgery is defined.
Journal Article↗
Drug Distribution in Obesity and following Bariatric Surgery: A Literature Review.
BACKGROUND: The pharmacokinetic variables of drug clearance and volume of distribution are usually corrected for body weight or surface area. Only recently have the relationships which exist between body size, physiologic function and pharmacokinetic variables been evaluated in the obese population. These effects are not widely known, and data on this and the effects of bariatric surgical procedures are scantily documented in the surgical literature. METHODS: Literature review. RESULTS: Drugs with a low or moderate affinity for adipose tissue have a moderate increase in the volume of distribution (Vd), and this correlates with the increase in lean body mass (LBM). Highly lipophilic drugs, with some exceptions, show the expected increase in Vd and prolongation of elimination half-life, indicating a marked distribution into adipose tissue. Drug absorption, in general, is slowed by delayed gastric emptying and is normal when gastric emptying is normal or increased. Most drug absorption occurs in the small intestine where duration of drug/mucosal contact is the most important factor. CONCLUSIONS: Drugs whose distribution is restricted to LBM should utilize a loading dose based on ideal body weight (IBW). For those drugs which distribute freely into adipose tissue, the loading dose should be based on total body weight (TBW). Adjustment of the maintenance dose depends on clearance rates. In a few cases dosage adjustment depends on pharmacodynamic data, since drug clearance does not conform to these recommendations, for reasons which remain to be defined. Following bariatric surgery, in the absence of delayed gastric emptying or uncontrolled diarrhea, drug absorption rates are usually comparable to the non-operated patient.
Journal Article↗
Metabolic Implications of Obesity, Weight Loss and Energy Expenditure following Gastric Restrictive Surgery.
This review examines the energetics and metabolic parameters which influence the effectiveness of gastric restrictive surgery in achieving weight loss in the clinically severely obese patient. Among the subjects discussed are the metabolic determinants and consequences of obesity, energy expenditure and its components, factors other than dietary restriction and weight loss which affect energy expenditure, and the metabolic risk factors for weight gain. The role of exercise is reviewed, including the effects of exercise on energy balance and the thermic effect of food. The value of combining exercise with diet restriction, the effect of caloric restriction on the capacity to exercise and the place of exercise in the obese diabetic are examined. Finally, the metabolic consequences of gastric restrictive surgery, the adaptive response to surgically-induced weight loss and nutritional recommendations following gastric restrictive surgery are reviewed.
Journal Article↗
Some Tips on Preparing Slides.
The author has drawn up instructions and warnings about slides for authors of abstracts accepted for presentation at the Annual Meeting of the American Society for Bariatric Surgery. These tips were invited for publication here, for wider use (Editor).
Journal Article↗
Effect of Surgically Induced Weight Loss on Asthma in the Morbidly Obese.
Forty morbidly obese asthmatic patients who underwent gastric restrictive surgery more than 2 years earlier were evaluated to determine the influence of weight loss on asthma outcome. Mean percentage excess weight loss in this group was 68% and body mass index (BMI) fell from a mean of 46 to 30. Following surgery, 90% showed improvement in asthma symptoms. Complete remission of asthma occurred in 48% and a further 12.5% became asthma free on reduced medications dosage. Of those taking daily medications for asthma before surgery, 42% were completely off medication following weight loss surgery, and another 18.5% experienced fewer asthma attacks on reduced medication dosage. Of the 22 patients with severe asthma (> 10 attacks per year) on routine daily medications for asthma preoperatively, 8(36%) required no medication after surgery, 7(32%) used medication only on an 'as-needed' basis, and 7(32%) controlled their asthma on reduced medication dosage. Five patients gained weight during the follow-up period. All developed an increased incidence of asthma attacks, which again abated after successfully losing weight following revisional surgery. Coexistent factors of smoking and clinically apparent esophageal reflux were evaluated, but no statistically significant correlation was shown with either smoking or reflux and improvement in asthma. Possible etiologies of the improvement in asthma with weight loss are discussed
Journal Article↗
Small Bowel Obstruction Following Gastric Bypass.
Intestinal obstruction is no more frequent after gastric bypass than after any other similar gastric surgical procedure. However, occurrence of any complication requiring revisional surgery in these hugely obese patients may have serious implications. Bariatric surgeons and physicians who take part in the care of such patients must be aware of the different clinical pictures which accompany the varying levels of obstruction following gastric bypass surgery. Particularly critical is an understanding of closed loop gastroduodenal obstruction, a potentially lethal complication, which can cause rapidly occurring hypovolemic shock and death within a few hours of onset.
Journal Article↗
Pulmonary Changes in Obesity: surgical implications. A Literature Review.
Obesity affects approximately one-third of the population of the United States. Pulmonary complications are common following upper abdominal surgery, and constitute the most frequent postoperative complication in the obese surgical patient. This literature review addresses the pathophysiology of the pulmonary changes associated with simple obesity and examines intraoperative and postoperative changes which occur in this patient group. Measures used prophylaxis and management of these complications are reviewed.
Journal Article↗
Revision of Staple Line Failure Following Roux-en-Y Gastric Bypass for Obesity: a follow-up of weight loss.
Eighty-one patients with primary Roux-en-Y gastric bypass for obesity underwent revisional surgery for staple-line failure. All patients (100%) were included in the follow-up. Two years later, patients had an excess weight loss of 77%; 91% of the patients had a final weight loss of 50% or more of their excess weight. Weight loss of revision patients was comparable to that reported for patients with primary operations. It was concluded that revision for staple line failure is clearly justified.
Journal Article↗
Age, Obesity Surgery, and Weight Loss.
Some centers consider an age over 50 to be a contraindication for obesity surgery. This study was conducted to examine the relationship between age and one-year postoperative weight of patients receiving gastric restrictive surgery (n = 616) for morbid obesity. Patients were divided into four age groups (18-29, 30-39, 40-49, 50-65 years) matched for preoperative obesity. At one year there were no statistically significant differences in weight loss or postoperative obesity. There were four (0.6%) surgically-related deaths. The mortality of patients aged 50 or older (1.1%) was not significantly higher than that of younger patients (0.6%). It was concluded that older age per se need not be a contraindication for surgery.
Journal Article↗
Folate Status Following Gastric Bypass Surgery (The Great Folate Mystery).
Several previous investigators have reported an incidence of folic acid deficiency following gastric bypass surgery of up to 38%. Failure to encounter any folic acid deficiencies in our postoperative patients led us to discontinue follow-up folate studies for several years. However, due to repeated references to this deficiency in the literature, we re-instituted folate studies as part of the routine follow-up of our patients. Preoperative serum folate levels were obtained in 1,067 patients and preexisting deficiencies found in 63, an incidence of 6%. Of the 588 folate levels determined 1 to 10 years following gastric bypass, only six were less than 3.0 ng/di, an incidence of 1%. All patients were instructed preoperatively and postoperatively to take multivitamin/mineral supplements after gastric restrictive surgery, and were continually educated on their importance. In a bariatric surgery practice in which patients are instructed, reminded, encouraged and even badgered into taking postoperative vitamin/mineral supplements, folate deficiency should be a rarity. In such circumstances, folate deficiency may well act as a sensitive marker of non-compliance.
Journal Article↗