Epidural Anesthesia and Analgesia : Their Role in Postoperative Outcome

This two-part meta-analysis combined data from eight prospective randomized trials designed to compare the nutritional efficacy of early enteral (TEN) and parenteral (TPN) nutrition in high-risk surgical patients. The combined data gave sufficient patient numbers (TEN, n = 118; TPN, n = 112) to adequately address whether route of substrate delivery affected septic complication incidence. Phase I (dropouts excluded) meta-analysis confirmed data homogeneity across study sites, that TEN and TPN groups were comparable, and that significantly fewer TEN patients experienced septic complications (TEN, 18%; TPN, 35%; p = 0.01). Phase II meta-analysis, an intent-to-treat analysis (dropouts included), confirmed that fewer TEN patients developed septic complications. Further breakdown by patient type showed that all trauma and blunt trauma subgroups had the most significant reduction in septic complications when fed enterally. In conclusion, this meta-analysis attests to the feasibility of early postoperative TEN in high-risk surgical patients and that these patients have reduced septic morbidity rates compared with those administered TPN.

We have previously reported that the frequencies of myocardial infarction and of sudden cardiac death are highest during the period from 6 a.m. to noon. Since platelet aggregation may have a role in triggering these disorders, we measured platelet activity at 3-hour intervals for 24 hours in 15 healthy men. In vitro platelet responsiveness to either adenosine diphosphate (ADP) or epinephrine was lower at 6 a.m. (before the subjects arose) than at 9 a.m. (60 minutes after they arose). The lowest concentration of these agents required to produce biphasic platelet aggregation decreased (i.e., aggregability increased) from a mean +/- SEM of 4.7 +/- 0.6 to 3.7 +/- 0.6 microM (P less than 0.01) for ADP and from 3.7 +/- 0.8 to 1.8 +/- 0.5 microM (P less than 0.01) for epinephrine. The period from 6 to 9 a.m. was the only interval in the 24-hour period during which platelet aggregability increased significantly. We subsequently studied 10 subjects on alternate mornings after they arose at the normal time and after delayed arising. The morning increase in platelet aggregability was not observed when the subjects remained supine and inactive. Thus, there is a temporal association between increased platelet aggregability in the morning and an increased frequency of myocardial infarction and of sudden cardiac death. Demonstration of this association does not establish a cause--effect relation, but together with other evidence linking platelets to these disorders, it may provide insight into the mechanisms precipitating myocardial infarction and sudden cardiac death and aid in the design of more effective preventive measures.