Magnitude Of Surgical Stress Research Articles

Anesthesiologists’ preferences for preoperative cardiac evaluation before vascular surgery: results of a mail survey

Study Objective To investigate whether anesthesiologists’ decisions to request preoperative cardiac evaluation (cardiologist consultation, echocardiography, and cardiac stress testing) before vascular surgery were influenced by patient comorbidity and magnitude of surgery; and to explore whether factors unrelated to the American College of Cardiology/American Heart Association (ACC/AHA) guidelines influence these decisions. Design Survey instrument. Setting University medical center. Subjects 2,000 U.S. anesthesiologists who were mailed a survey. Measurements Six factors in a hypothetical patient presenting for vascular surgery [gender, race (white vs. black), age (65 yrs vs. 85 yrs), comorbidities (sick vs. healthy), functional status, and magnitude of surgical stress] were evaluated. Respondents were asked about their demographics, practice patterns, and how they would manage the hypothetical patient. Main Results Of 2,000 mailed surveys, 439 U.S. anesthesiologists responded (22%). Multivariate ordinal logistic regression analysis showed that anesthesiologists were more likely to recommend preoperative cardiology consultation for patients with more comorbidities [odds ratio = 5.53; 95% confidence interval (CI) = 3.76, 8.15], for those with poorer functional status (odds ratio = 1.45; 95% CI = 1.02, 2.07), for those undergoing a more significant surgery (odds ratio = 1.61; 95% CI = 1.13, 2.30), as the clinicians’ estimated risk of perioperative myocardial infarction increased ( P < 0.001), or if they only infrequently anesthetized patients such as the one described in the scenario ( P = 0.05). They also would request a preoperative echocardiogram for patients with more comorbidities (odds ratio = 2.58; 95% CI = 1.80, 3.68) and for those undergoing a more significant surgery (odds ratio = 1.59; 95% CI = 1.12, 2.25). A preoperative stress test was recommended for patients with more comorbidities (odds ratio = 3.01; 95% CI = 2.06, 4.38) and for those with a more significant surgery (odds ratio = 1.74; 95% CI = 1.15, 2.63). Other factors associated with request for a preoperative stress test were female gender of the anesthesiologist (odds ratio = 1.79; 95% CI = 1.11, 2.87), those with less experience with such patients ( P = 0.05), and those from New England (odds ratio = 2.16; 95% CI = 1.01, 4.62). Conclusions Anesthesiologists’ preferences for preoperative cardiac evaluation are generally consistent with evidence-based and expert-based AHA/ACC guidelines. However, other physician factors (ie, gender, years in practice, and familiarity with the surgical procedure) also influenced these decisions.

Predictors of Perioperative β-Blockade Use in Vascular Surgery: A Mail Survey of United States Anesthesiologists

It was hypothesized that anesthesiologists' decisions to provide perioperative beta-blockade during vascular surgery would be influenced more by physician factors than by those of their patients. Mail survey. Case presentation. Four hundred thirty-nine anesthesiologists in the United States who responded to a survey. By using Microsoft Word Mail Merge (Microsoft, Redmond, WA), 6 factors in a hypothetical patient presenting for vascular surgery (sex, race, age, comorbidities, functional status, and magnitude of surgical stress) were randomly varied. The response rate was 22%. Self-reported propensity to use beta-blockade was significantly increased among anesthesiologists who worked in New England, among those who worked in larger hospitals, or who had received fellowship training. Among healthy patients, beta-blockers were more likely to be used for older than younger patients. Among sicker patients, however, the reverse was true. Heart rate triggers for beta-blockade use were higher than heart rates associated with improved outcomes in pivotal beta-blocker trials. Preferences for perioperative beta-blockade use in vascular surgery patients are influenced by anesthesiologists' demographics as well as patient comorbidities or degree of surgical stress. This finding suggests that efforts to increase perioperative beta-blockade in high-risk vascular patients face significant barriers from some groups of clinicians.

Metabolic Response to Stress in the Neonate Who Has Surgery

After completing this article, readers should be able to: 1. Describe the basic metabolic pathways involved in neonatal nutrition. 2. Describe the effect of stress on nutrition and metabolism in the neonate undergoing surgery. 3. Describe the differences in the metabolic response to stress between an adult and a neonate. Over the past 4 decades, there have been remarkable improvements in our ability to care for critically ill infants. Progress in surgical and critical care of neonates has led to improved survival rates. Our understanding of the nutritional requirements of infants continues to advance. In contrast to years past, practitioners caring for critically ill infants undergoing surgery today have various nutritional options, including specialized parenteral and enteral formulations. Although our understanding of host defense and nutritional support continues to evolve, the interplay between the immune system and metabolism is being investigated. Hence, we are improving the match between the infant’s energy expenditure and nutritional requirements. Critical to further progress is additional understanding of the metabolic response of a neonate to surgical stress. All living organisms require energy to survive. Fuel sources enter into complex metabolic cascades to form the ultimate energy substrate, adenosine triphosphate (ATP), a fuel needed to drive and maintain all physiologic systems. Under stressful conditions, intrinsic substrate mobilizes to synthesize additional energy substrate. In essence, host substrate is mobilized for the promotion of healing after injury. Cytokines, released in response to injury, drive the catabolic response to stress, but in abundance, as with the systemic inflammatory response syndrome (SIRS), cytokines are detrimental to the organism. The nutritional requirements of a neonate are significantly greater than those of an adult because not only are there requirements for substrate intake to fulfill basic metabolic needs, but there are metabolic needs to maintain rapid and continued growth and development. Furthermore, the metabolic response …

Changes in Lymphocyte β2-Adrenoceptors after Hepatic Resection

Hepatic resection promotes such a high degree of surgical stress that it induces deterioration of various vital functions, which may involve the breakdown of signal transduction systems. To investigate the influence of surgical stress on signal transduction, we studied ligand-receptor specific binding activity after hepatic resection, focusing on lymphocyte β2-adrenoceptors. The maximum binding capacity ( B max) and the dissociation constant (KD) were determined by radioligand binding assay using (-) 3H-CGP12177 as a ligand. In the hepatectomy group, B max significantly decreased from 1380 ± 109 to 799 ± 49 receptors/cell on postoperative day (POD) 3 and to 802 ± 93 receptors/cell on POD 7 ( P < 0.05). In the control group, however, it did not significantly change after the operation. No significant changes in K dcl025; were found in either of these groups. The B max alteration was not due to the redistribution of lymphocyte subsets or receptor down regulation, but to the decrease in the B max of the individual subset. The hepatectomy group was divided into two groups according to the postoperative arterial ketone body ratio (AKBR): Group A, AKBR maintained at 0.7 or more; and Group B, AKBR decreased to below 0.7. The B max decrease, a percentage of the preoperative value, of Group B was significantly smaller than that of Group A (48.4 ± 3.9 and 72.3 ± 7.3%, respectively, P < 0.05). These results suggest that intense surgical stress, produced by hepatic resection, may influence even ligand-receptor binding parameters, and the decrease in AKBR can indicate the magnitude of surgical stress.

Interleukin-6 and granulocytic elastase levels following laparoscopic cholecystectomy

Interleukin-6 (IL-6) levels have been shown to correlate well with the magnitude of surgical stress. Serum IL-6 and plasma granulocytic elastase levels, 24 h after surgery, were determined in 12 patients who underwent open major surgery [MS group; esophageal carcinoma (n=5), gastric carcinoma (n=3), colorectal carcinoma (n=4) 5 patients who had open cholecystectomy [OC group] and 17 patients who had laparoscopic cholecystectomy [LC group]. IL-6 levels correlated significantly with the duration of surgery (r=0.685,P < 0.01) and with intraoperative blood loss (r=0.583,P < 0.02). However, there was no significant correlation between granulocytic elastase and the duration of surgery or blood loss. Plasma IL-6 levels in the LC group (21±3 pg/ml) were significantly lower than those in the OC group (47±5 pg/ml) and the MS group (186±36pg/ml) (P<0.05;P<0.01). However, there was no significant difference in granulocytic elastase levels between the LC group (318±8μg/l), the OC group (360±130 gmg/ml), and the MS group (701±344 μg/l). Increased IL-6 levels correlated well with increased duration of surgery. The lower IL-6 levels following laparoscopic cholecystectomy may therefore be indicative of lower surgical stress associated with laparoscopic cholecystectomy.

Growth hormone response to gastrectomy.

The fluctuation of the plasma level of human growth hormone (HGH), in relation to blood sugar and plasma non-esterified fatty acid (NEFA) levels, was investigated, both before and after surgery, in thirty-four subjects, who had received gastrectomy due to either peptic ulcer or gastric cancer. The level of HGH was markedly elevated immediately after the commencement of surgery and arrived at a peak after 30 to 60 minutes. Thereafter the level gradually fell despite the continuation of surgery. Up untill the seventh postoperative day the levels during fasting showed no marked fluctuation. These HGH fluctuations bore no definite relationship to the nature of intra-operative infusions, age, sex, obsity or magnitude of surgical stress. From the fact that the elevation of NEFA release followed the elevation of HGH, it is recognized that increased release of HGH upon surgical stress greatly contributes to fat metabolism during this period. It is also suggested that the release of HGH might induce a fall in glucose utilization resulting a diabetogenicity immediately after surgical stress.