Clinical evaluation of hormonal stress state in medical ICU patients: a prospective blinded observational study

Elevations in growth hormone and glucagon-like peptide-2 levels on admission are associated with increased mortality in trauma patients

BACKGROUND

Burn and trauma patients present a clinical challenge due to metabolic derangements and hypermetabolism that result in a prolonged catabolic state with impaired healing and secondary complications, including ventilator dependence. Previous work has shown that circulating levels of growth hormone (GH) are predictive of mortality in critically ill adults, but few studies have examined the prognostic potential of GH levels in adult trauma patients.

METHODS

To investigate the utility of GH and other endocrine responses in the prediction of outcomes, we conducted a prospective, observational study of adult burn and trauma patients. We evaluated the serum concentration of GH, insulin-like growth factor 1 (IGF-1), IGF binding protein 3 (IGFBP-3), and glucagon-like peptide-2 (GLP-2) weekly for up to 6 weeks in 36 adult burn and trauma patients admitted between 2010 and 2013.

RESULTS

Non-survivors had significantly higher levels of GH and GLP-2 on admission than survivors.

DISCUSSION

This study demonstrates that GH has potential as a predictor of mortality in critically ill trauma and burn patients. Future studies will focus on not only the role of GH, but also GLP-2, which was shown to correlate with mortality in this study with a goal of offering early, targeted therapeutic interventions aimed at decreasing mortality in the critically injured.

CONCLUSIONS

GH and GLP-2 may have clinical utility for outcome prediction in adult trauma patients.

Glucagon levels, disease severity, and outcome in severe sepsis

PURPOSE

Few studies on plasma glucagon levels in patients with sepsis have been performed. We aimed to assess clinical value of glucagon levels in comparison with clinical parameters and severity scores in patients with severe sepsis or septic shock.

METHODS

A total of 112 patients who were admitted to intensive care unit with severe sepsis or septic shock were included. Plasma levels of glucagon on days 0, 1, 3, and 7 were serially measured in 112 patients with severe sepsis or septic shock.

RESULTS

Compared with survivors, patients who died within 28 days had significantly higher glucagon levels on every day of examination. Glucagon levels were positively correlated with and Acute Physiology and Chronic Health Evaluation II score (day 0, r = 0.288, P < 0.01) and Sequential Organ Failure Assessment (day 0, r = 0.482, P< 0.01; day 1, r = 0.588, P < 0.01; day 3, r = 0.480, P < 0.01; day 7, r = 0.454, P < 0.01). Receiver operating characteristic analysis showed that the area under the curve of glucagon levels to predict 28-day survival was 0.65 (95% confidence interval [CI], 0.55-0.75; P = 0.005), similar to the Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores. Multivariate analysis revealed that glucagon levels of greater than 70 pg/mL (hazard ratio, 1.85; 95% CI, 1.03-3.29) and chronic liver disease (hazard ratio, 1.97; 95% CI, 1.02-3.79) were associated with mortality.

CONCLUSIONS

Glucagon levels might reflect disease severity and clinical outcomes in patients with severe sepsis or septic shock.

Predictors of Circulating Insulin-Like Growth Factor-1 and Insulin-Like Growth Factor-Binding Protein-3 in Critical Illness

OBJECTIVE

To characterize predictors of insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 in acute critical illness with the hypothesis that acute factors associated with critical illness will more strongly predict circulating insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 than chronic clinical or genetic factors.

DESIGN

Observational study nested within a large prospective study using multivariable linear regression to model circulating insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 with acute and chronic clinical variables, and genotype from five polymorphisms in insulin-like growth factor pathway genes.

SETTING

ICUs from two large academic medical centers.

PATIENTS

Five hundred forty-three Caucasian patients with risk factors for acute respiratory distress syndrome and available plasma from early in critical illness.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Total insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 were measured in plasma using IMMULITE assays (Siemens, Malvern, PA). We examined age, gender, body mass index, cirrhosis, and diabetes, as well as Acute Physiology, Age, and Chronic Health Evaluation III score, acute hepatic dysfunction, pneumonia and aspiration, sepsis/septic shock, acute respiratory distress syndrome, and receipt of corticosteroids. Body mass index, cirrhosis, and acute respiratory distress syndrome were strongly associated with insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 levels; Acute Physiology, Age, and Chronic Health Evaluation III was strongly associated with insulin-like growth factor-1 levels; and age was strongly associated with insulin-like growth factor-binding protein-3. Five polymorphisms (IGF1: rs1520220, rs35767, rs2946834; IGFBP1: rs4619; IGFBP3: rs2854746) were analyzed for associations with plasma levels. When genotypes were added to models, rs2854746 was significantly associated with plasma insulin-like growth factor-binding protein-3. Genotype explained an additional 2% of variability with an overall adjusted R-square of 0.18.

CONCLUSIONS

Despite the acute derangements of critical illness, both acute and chronic health factors significantly influence circulating levels of insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 early in critical illness. rs2854746 is also significantly associated with insulin-like growth factor-binding protein-3 levels in this ICU cohort. Overall, phenotypic and genotypic factors explained only a modest amount of variability in insulin-like growth factor-1 and insulin-like growth factor-binding protein-3. Further research is needed to understand how to apply these findings to patient care.

Subcutaneous hydrocortisone administration for emergency use in adrenal insufficiency

OBJECTIVE

Evaluation of the pharmacokinetics and safety of s.c. hydrocortisone injection for use in adrenal emergency.

DESIGN

Single-center, open-label, sequence-randomized, crossover study in a tertiary care center.

PATIENTS AND METHODS

Twelve patients with chronic Addison's disease. Comparison of hydrocortisone pharmacokinetics after s.c. and i.m. injection (100 mg) and after s.c. administration of sodium chloride (0.9%) respectively at three different visits.

MAIN OUTCOME MEASURE

maximum serum cortisol (Cmax), time to Cmax (tmax), and time to serum cortisol >36 μg/dl (tserum cortisol >36 μg/dl) after s.c. administration compared with i.m. administration, safety, and patient preference.

RESULTS

Serum cortisol increased rapidly and substantially after both i.m. and s.c. injections (Cmax: 110±29 vs 97±28 μg/dl, P=0.27, tmax: 66±51 vs 91±34 min, P=0.17, and tserum cortisol >36 μg/dl: 11±5 vs 22±11 min, P=0.004 respectively). Both i.m. and s.c. injections were well tolerated. Eleven (91.7%) patients preferred s.c. injection, whereas one patient did not have any preference.

CONCLUSIONS

S.c. administration of 100 mg hydrocortisone shows excellent pharmacokinetics for emergency use with only a short delay in cortisol increase compared with i.m. injection. It has a good safety profile and is preferred by patients over i.m. injection.

Glucose control in the intensive care unit: a nutrition support perspective

Hyperglycemia commonly occurs in acutely ill patients who receive nutrition support, even in patients without a history of diabetes. The traditional view that stress hyperglycemia may be a beneficial adaptive response has been replaced by data linking hyperglycemia with increased morbidity and mortality in critically ill populations. Initial randomized studies to control stress hyperglycemia with intensive insulin infusion reported dramatic decreases in infectious complications and decreased mortality. However, recent large multicenter trials have reported that intensive insulin therapy designed to normalize blood glucose resulted in an unacceptable increase in the incidence of hypoglycemia. Review of the methods, protocols, and nutrition provided during these randomized studies is crucial to understanding the different conclusions reached and how these results may be used to influence protocols in intensive care units today. Evidence is reviewed and practical considerations are provided for nutrition support regimens to minimize stress hypoglycemia and assist glucose management.

Use of a continuous glucose sensor in an extracorporeal life support circuit

BACKGROUND

Standard care for infants on extracorporeal life support (ECLS) relies on intermittent measurement of blood glucose (BG); however, this can lead to significant changes in BG that go unrecognized for several hours. The present study was designed to assess performance and clinical applicability of a subcutaneous glucose sensor technology modified for use as a blood-contacting sensor within the ECLS circuit.

METHODS

Twelve children, aged 3 years or less, requiring ECLS support were studied. Three continuous glucose sensors (Medtronic MiniMed) were inserted into hubs placed in line with the ECLS circuit. Blood glucose was assessed with a laboratory analyzer (BG(LAB); Bayer Rapidlab 860) approximately every 5 h (mean 4.9 ± 3.3 h) with more frequent samples obtained with a bedside monitor (HemoCue) as needed. Sensor current (I(SIG)) was transmitted to a laptop computer and retrospectively calibrated using BGLAB. Sensor performance was assessed by mean absolute relative difference (MARD), linear regression slope and intercept, and correlation, all with BGLAB as reference.

RESULTS

The BGLAB averaged 107.6 ± 36.4 mg/dl (mean ± standard deviation) ranging from 58 to 366 mg/dl. The MARD was 11.4%, with linear regression slope (0.86 ± 0.030) and intercept (9.0 ± 3.2 mg/dl) different from 1 and 0, respectively (p < .05), and correlation (r² = 0.76; p < .001). The system was not associated with any adverse events, and placement and removal into the hubs was easily accomplished. Instances in which more frequent BG values were obtained using a bedside HemoCue (BGHEMO) monitor showed the sensor to respond rapidly to changes.

CONCLUSIONS

We conclude that continuous sensors can be adapted for use in an ECLS circuit with accuracy similar to or better than that achieved with the subcutaneous site. Continuous glucose monitoring in this population can rapidly detect changes in BG that would not otherwise be observed. Further studies will be needed to assess the benefit of continuous glucose monitoring in this population.