Divertie, Gavin D.

To determine whether the sensitivity of adipose tissue lipolysis to catecholamines is increased in poorly controlled insulin-dependent diabetes, the lipolytic response to epinephrine was measured in seven nondiabetic volunteers and seven poorly controlled diabetic subjects with use of [1-(14)C]palmitate as a tracer. Subjects received sequential 1-h infusions of epinephrine, which produced epinephrine concentrations of approximately 1,000, approximately 1,750, approximately 3,500, and approximately 6,000 pmol/l. A pancreatic clamp was used to maintain constant plasma hormone levels. Concentration-response curves were constructed for each subject from the integrated lipolytic response during each epinephrine infusion. There was no difference in maximal lipolytic response (117 +/- 19 vs. 152 +/- 11 mumol.kg-1.h-1) or in maximally effective (3,171 +/- 267 vs. 3,357 +/- 349 pmol/l) or half-maximally effective (1,081 +/- 109 vs. 1,015 +/- 120 pmol/l) epinephrine concentrations between nondiabetic and diabetic subjects, respectively (all P = NS). In control subjects, maximum beta-hydroxybutyrate concentrations were achieved at lower epinephrine concentrations than those required for a maximum lipolytic effect. Thus, under pancreatic clamp conditions, the lipolytic response to epinephrine in nondiabetic and diabetic subjects was similar.

Controversy exists regarding whether plasma glucose concentrations are independently involved in the regulation of adipose tissue lipolysis. In the present study, six subjects with insulin-dependent diabetes and six nondiabetic volunteers were studied during infusion of somatostatin, growth hormone, and insulin at rates designed to maintain basal rates of lipolysis, which was traced using a constant infusion of [1-14C]palmitate. A euglycemic (approximately 5 mmol/l) clamp was performed for 3 h, followed by 3 h of hyperglycemia (approximately 9 and approximately 11 mmol/l in nondiabetic and diabetic subjects, respectively). Ten nondiabetic subjects were studied during 6 h of euglycemia to exclude time-dependent changes in lipolysis. The results showed that palmitate concentrations did not change between euglycemia and hyperglycemia in either group [118 +/- 10 vs. 132 +/- 14 mumol/l and 145 +/- 21 vs. 134 +/- 15 mumol/l in nondiabetic and diabetic subjects, respectively; both P = not significant (NS)]. Similarly, palmitate rate of appearance (Ra) did not change during hyperglycemia (1.0 +/- 0.1 and 1.7 +/- 0.4 mumol.kg-1.min-1 in nondiabetic and diabetic subjects, respectively) compared with euglycemia (1.0 +/- 0.1 and 1.6 +/- 0.4 mumol.kg-1.min-1 in nondiabetic and diabetic subjects, respectively; P = NS). Palmitate concentrations and Ra did not change during 6 h of euglycemia in nondiabetic volunteers. Thus hyperglycemia per se has no effect on free fatty acid turnover. Changes in lipolysis that occur coincident with hyperglycemia are probably due to changes in other circulating substrates or hormones known to affect lipolysis.

Context: The delivery of end-of-life care (EOLC) in the intensive care unit (ICU) varies widely among medical care providers. The differing opinions of nurses and physicians regarding EOLC may help identify areas of improvement. Objective: To explore the differences of physicians and nurses on EOLC in the ICU and how these differences vary according to self-reported proficiency level and primary work unit. Design: Cross-sectional survey of 69 ICU physicians and 629 ICU nurses. Setting: Single tertiary care academic medical institution. Results: A total of 50 physicians (72%) and 331 nurses (53%) participated in the survey. Significant differences between physicians and nurses were noted in the following areas: ability to safely raise concerns, do not resuscitate (DNR) decision making, discussion of health care directives, timely hospice referral, spiritual assessment documentation, utilization of social services, and the availability of EOLC education. In every domain of EOLC, physicians reported a more positive perception than nurses. Additional differences were noted among physicians based on experience, as well as among nurses based on their primary work unit and self-reported proficiency level. Conclusions: Even with an increased focus on improving EOLC, significant differences continue to exist between the perspectives of nurses and physicians, as well as physicians among themselves and nurses among themselves. These differences may represent significant barriers toward providing comprehensive, consistent, and coordinated EOLC in the ICU.