Systemic Stress Hormone Response in Patients Undergoing Open Heart Surgery With or Without Cardiopulmonary Bypass

Vitamin D supplementation protects against reductions in plasma 25-hydroxyvitamin D induced by open-heart surgery: Assess-d trial

Low vitamin D (serum or plasma 25‐hydroxyvitamin D (25(OH)D)) is a global pandemic and associates with a greater prevalence in all‐cause and cardiovascular mortality and morbidity. Open‐heart surgery is a form of acute stress that decreases circulating 25(OH)D concentrations and exacerbates the preponderance of low vitamin D in a patient population already characterized by low levels. Although supplemental vitamin D increases 25(OH)D, it is unknown if supplemental vitamin D can overcome the decreases in circulating 25(OH)D induced by open‐heart surgery. We sought to identify if supplemental vitamin D protects against the acute decrease in plasma 25(OH)D propagated by open‐heart surgery during perioperative care. Participants undergoing open‐heart surgery were randomly assigned (double‐blind) to one of two groups: (a) vitamin D (n = 75; cholecalciferol, 50,000 IU/dose) or (b) placebo (n = 75). Participants received supplements on three separate occasions: orally the evening before surgery and either orally or per nasogastric tube on postoperative days 1 and 2. Plasma 25(OH)D concentrations were measured at baseline (the day before surgery and before the first supplement bolus), after surgery on postoperative days 1, 2, 3, and 4, at hospital discharge (5–8 days after surgery), and at an elective outpatient follow‐up visit at 6 months. Supplemental vitamin D abolished the acute decrease in 25(OH)D induced by open‐heart surgery during postoperative care. Moreover, plasma 25(OH)D gradually increased from baseline to day 3 and remained significantly increased thereafter but plateaued to discharge with supplemental vitamin D. We conclude that perioperative vitamin D supplementation protects against the immediate decrease in plasma 25(OH)D induced by open‐heart surgery.

ClinicalTrials.gov Identifier: NCT02460211.

Anesthetic Induction With Etomidate in Cardiac Surgical Patients: A PRISMA-Compliant Systematic Review and Meta-Analysis

OBJECTIVE

This meta-analysis aimed to systematically review the effects of etomidate (ETM) during anesthetic induction on patients undergoing cardiac surgery.

DESIGN

Systematic review and meta-analysis.

SETTING

Operating room.

PARTICIPANTS

Patients undergoing cardiac surgery.

INTERVENTIONS

ETM or control drugs.

MEASUREMENTS AND MAIN RESULTS

PubMed, Cochrane Library, OVID, and EMBASE were searched through August 31, 2020. Primary outcomes included hemodynamic profiles and stress responses. Secondary outcomes included morbidity, mortality, and postoperative recovery. For continuous/dichotomous variables, treatment effects were calculated as weighted mean difference (WMD)/odds ratio (OR) and 95% confidence interval (CI). A database search yielded 18 randomized controlled trials including 1,241 patients. The present meta-analysis demonstrated that ETM-anesthetized patients had lower heart rates (WMD, -3.31; 95% CI -5.43 to -1.19; p = 0.002), higher blood pressures (systolic blood pressure: WMD, 12.02; 95% CI 6.24 to 17.80; p < 0.0001; diastolic blood pressure: WMD, 5.23; 95% CI 2.39 to 8.08; p = 0.0003; mean arterial pressure (MAP): WMD, 8.64; 95% CI 5.85 to 11.43; p < 0.00001), less requirement for vasopressor (OR, 0.26; 95% CI 0.15 to 0.44; p < 0.00001), and more nitroglycerin usage (OR, 14.89; 95% CI 4.92 to 45.08; p < 0.00001) during anesthetic induction. Current meta-analysis also demonstrated that single-dose ETM lowered cortisol levels transiently and did not have a significant effect on endogenous norepinephrine and epinephrine levels and was not associated with increased postoperative inotrope and/or vasopressor requirement. Additionally, the meta-analysis suggested that ETM anesthesia was associated with neither increased mortality nor morbidity, except a higher incidence of transient adrenal insufficiency in ETM recipients.

CONCLUSION

The present meta-analysis suggested that single-dose ETM during anesthetic induction could be associated with more stable hemodynamics, transient and reversible lower cortisol levels, and a higher adrenal insufficiency incidence, but not worse outcomes in cardiac surgical patients.

Effect of family presence on stress response after bypass surgery

BACKGROUND

Coronary artery bypass grafting (CABG) is a major surgery that may cause severe surgical stress response (SR). Although the presence of family members in intensive care unit (ICU) is known to benefit intensive care patients socially and emotionally, its effects on surgical SR are unknown.

OBJECTIVES

To investigate the effect of an informed family member (IFM)'s presence in the awakening process in ICU on patients' SR after CABG.

METHODS

A nonrandomized controlled clinical study was completed with a total of 73 patients: 37 patients in the control (CG) and 36 in the intervention group (IG) underwent CABG surgery. In the CG patients, no family members were taken into the ICU during the awakening process and routine care and treatment practices were continued. In the IG patients, besides routine care and treatment practices, an IFM was taken into the ICU during the awakening process in accordance with the research method. Groups were statistically compared in terms of serum cortisol level which is the one of the main indicators of surgical SR, state anxiety, sedative drug requirements, and duration of intubation, sedation, and ICU stay. A p value <0.05 was accepted as statistically significant.

RESULTS

Presence of an IFM in the ICU was found to be effective in decreasing serum cortisol level, state anxiety, sedative drug requirements, and the duration of intubation, sedation, and ICU stay (p<0.05).

CONCLUSIONS

In CABG, the presence of IFM in ICU is effective in reducing SR.

Effect of statin on perioperative myocardial injury in isolated valve surgery

BACKGROUND

Statins have known pleiotropic effects that confer protection from ischemia-reperfusion injury. Because cardiopulmonary bypass is a potentially reversible ischemia-reperfusion sequence, we aimed to assess whether statin loading could help to limit myocardial injury in patients undergoing isolated heart valve replacement under cardiopulmonary bypass.

METHODS

One hundred patients with rheumatic valvular heart disease undergoing valve replacement received either a loading dose of rosuvastatin (40 mg initiated 7 days before surgery; loaded group) or no statins (non-loaded group). Cardiac troponin I, creatine kinase MB, and brain natriuretic peptide were measured at 8, 24, and 48 hours postoperatively. The primary endpoint was the extent of perioperative myocardial injury measured by the area under the curve for each biomarker.

RESULTS

Despite similar baseline levels, all biomarkers at 8, 24, and 48 h were significantly lower in the loaded group. The area under the curve of each biomarker was significantly lower in the loaded group than in the non-loaded group (troponin I: 31.43 vs. 77.21 ng·h·mL^-1, creatine kinase MB 309.31 vs. 429.12 ng·h·mL^-1, brain natriuretic peptide 5176.11 vs. 16119.31 pg·h·mL^-1, all p < 0.001). The mean changes from baseline to peak levels were also significantly lower in the loaded group. The loaded group had a shorter hospital stay but no significant difference was seen in ventilator time, inotrope time, aortic crossclamp time, cardiopulmonary bypass time, or intensive care unit stay.

CONCLUSION

In patients undergoing valve replacement, high-dose statin loading before surgery had a favorable impact on the release kinetics of various cardiac biomarkers.

Effects of dexmedetomidine on stress hormones in patients undergoing cardiac valve replacement: a randomized controlled trial

Background

Stress response always occurs in cardiac valve replacement patients undergoing cardiopulmonary bypass (CPB).

Methods

60 patients undergoing cardiac valve replacement were recruited and randomized into control and Dex groups. Dex group received 1.0 μg·kg-1 of Dex for 10 min intravenously before anesthesia, followed by 0.5 μg·kg-1·h-1 of Dex, steadily administered throughout the procedure. And controlled group received the identical velocity of saline as Dex group. Plasma level of cortisol (Cor), epinephrine (E), norepinephrine (NE), and serotonin (5-HT) were evaluated at four timepoints: Before administration (T0), sawn sternum (T1), end of extracorporeal circulation (T2), and 24 h post operation (T3). General data of operation and recovery such as heart rate (HR), mean arterial pressure (MAP), intraoperative bispectral index (BIS), and hospitalization time in the intensive care unit (ICU) were also compared.

Results

Increase of Cor, E, NE, and 5-HT for the Dex group was significant lesser than that in the control group (P < 0.05), and ICU hospitalization time and ventilator support time was significantly shorter in the Dex group. The proportion of patients discharged from the hospital with better prognosis was significantly higher than that in the control group, while there were no significant differences in hospitalization costs and vasoactive drugs use between the two groups.

Conclusions

Dex reduces plasma Cor, E and NE elevations in patients after CPB, alleviates the stress reaction of the body, shortens the hospitalization time and ventilator support time in ICU, and plays a positive role in the rehabilitation of patients undergoing cardiac valve replacement.

Trial registration

China Clinical Trial Registry (No. ChiCTR-IPR-17010954) March 22rd, 2017.

The association of systemic inflammatory markers with indicators of stress and cardiac necrosis in patients undergoing aortic valve replacement and revascularization surgeries

The aim was to investigate: changes of inflammatory, stress and cardiac response in patients undergoing open heart surgeries up to five days after the procedure; the association between inflammatory, stress and cardiac response and whether changes in a certain marker can predict short-term patient outcome. Ninety patients were divided into three groups, 30 participants each (on-pump,off-pump revascularization and valve replacement group). The following markers were measured:complete blood count, CRP, IL-6, IL-10, leptin, resistin, monocyte chemoattractant protein-1 (MCP-1), cortisol, CK and hsTnT in 5 points. Resistin increased in all three groups. Lower IL-10 levels were found after the surgery and higher levels of leptin and MCP-1 in the off-pump than in the on-pump group. Off-pump group had higher values of IL-6, IL-10, leptin, resistin and MCP-1 and lower levels of CK and hsTnT 24 after surgery than the on-pump group. We found significant correlation between MCP-1 and resistin. The difference between resistin at time points 2 and 3 significantly predicted transfusion needs; while the difference between CRP and resistin before and at the end of the surgery together with the difference between leukocytes at the end and 24 hours after the surgery predicted the use of inotropic agents/vasopressors. Cardiac surgeries cause an increase of inflammatory, stress and cardiac markers. Only resistin correlated with MCP-1 which confirms the link between resistin secreted form infiltrated macrophages and enhanced release of MCP-1.

Assessment of adrenal reserve and secretion of cortisol in patients over 60 years of age undergoing cardiac surgery

Introduction

Cortisol level affects the prognosis of patients after cardiac surgery. Meanwhile, there are no clear guidelines for steroid supplementation after a cardiac operation. The relationship between age and blood cortisol levels has not been finally clarified.

Aim

Assessment of adrenal reserve and secretion of cortisol in patients over 60 years of age undergoing cardiac surgery.

Material and methods

The study included 20 patients of both sexes referred for cardiac surgery. A short ACTH synthetic stimulation test was carried out. Assessment of cortisol secretion was carried out in the morning on the day of surgery and the 1^st, 2^nd and 4^th days after surgery in blood samples.

Results

A result within the normal range for the adrenal reserve was found in 19 of the 20 patients enrolled in the study. The short Synacthen test predicted postoperative secretion of cortisol (p = 0.04, r = 0.047). A relationship between secretion of cortisol and patients’ age was observed (p = 0.03, r = 0.48). The concentration of cortisol on the 1^st postoperative day was correlated with the total dose of dopamine (p = 0.006, r = 0.58) and adrenaline (p = 0.04, r = 0.47). The concentration of cortisol on the day of the surgery correlated with the lactate concentration on day 2 (p = 0.04, r = 0.45). The concentration of lactates on day 1 correlated with total dose of dopamine (p = 0.01, r = 0.54).

Conclusions

A short Synacthen test allows one to predict secretion of cortisol after cardiac surgery. Greater secretion of cortisol after cardiac surgery may be associated with a more difficult postoperative course. There was no decrease in cortisol secretion with age.

Cortisol Response in Children After Second Cardiopulmonary Bypass

A surge in cortisol levels is seen after surgery with cardiopulmonary bypass (CPB). Based on evidence of attenuation of the cortisol response to repeated stress in other settings, we hypothesized that the magnitude of cortisol increase in children after a second exposure to CPB would be reduced. Serial cortisol levels were measured at three time points after each CPB: immediately (day 0), on the first morning (day 1), and second morning (day 2). Forty-six children underwent two surgeries with CPB during the study period. The mean age (standard deviation) at first and second surgery was 3.5 (6.3) months and 10.4 (9.9) months, respectively. Cortisol levels at the first surgery were 109 (105) µg/dl, 29 (62) µg/dl, and 17 (12) µg/dl on day 0, 1, and 2, respectively; similarly at second surgery, it was 61 (57) µg/dl on day 0 to 20 (16) µg/dl and 11 (10) µg/dl on day 1 and 2, respectively. After log-transformation and adjusting for time interval between surgeries, cortisol levels at the second surgery were lower by 42% on day 0 (p = 0.02), and 46% lower on day 2 (p = 0.02). A second exposure to CPB in children with congenital heart disease is associated with an attenuated cortisol release.

A Prospective Cohort Evaluation of the Cortisol Response to Cardiac Surgery with Occurrence of Early Postoperative Cognitive Decline

BACKGROUND A recent study reported that patients with higher cortisol levels on the 1st postoperative morning after cardiac surgery exhibited an increased risk of early postoperative cognitive decline (POCD). Therefore, we conducted the current study to gain further insight into the stress response to a surgical procedure as a potential risk factor for early POCD after cardiac surgery. MATERIAL AND METHODS This prospective cohort study enrolled 125 patients undergoing elective cardiac surgery with or without cardiopulmonary bypass (CPB). Patient serum cortisol levels were determined 1 day before surgery (at 08: 00) and on the 1st (at 08: 00, 16: 00 and 24: 00), 3rd (at 08: 00), and 5th (at 08: 00) postoperative days. A battery of 9 neuropsychological tests were used to assess the participants 2 days before the surgical procedure and on the 6th postoperative day. POCD was defined as a decrease in performance of 1 SD or greater between the postoperative and preoperative z scores on at least 1 neuropsychological test. A mixed-design ANOVA was used to determine the correlations of the perioperative cortisol levels with the occurrence of POCD and with the surgical technique performed. RESULTS Mixed-design ANOVA showed no statistically significant differences in the cortisol levels between non-POCD and POCD patients (F=0.52, P=0.690) or between patients with and without CPB (F=2.02, P=0.103) at the 6 perioperative time points. CONCLUSIONS The occurrence of early POCD and the use of CPB were not associated with significantly higher cortisol levels in the repeated measurement design.

Effects of Preoperative Psychological Interventions on Catecholamine and Cortisol Levels After Surgery in Coronary Artery Bypass Graft Patients: The Randomized Controlled PSY-HEART Trial

OBJECTIVE

The aim of the study was to examine whether preoperative psychological interventions targeting patients' expectations are capable of influencing the biological stress response after coronary artery bypass graft (CABG) surgery and could thus improve recovery after heart surgery.

METHODS

Randomized controlled trial with assessments 10 days before surgery, after psychological intervention (day of hospital admission, but before surgery), postoperative (6-8 days later), and at follow-up (6 months after surgery). Eligible patients (N = 124) scheduled for elective on-pump CABG or CABG with valve replacement surgery were approached before hospital admission. Standard medical care (SMC) was compared with two additional preoperative psychological interventions: (a) an expectation manipulation intervention to optimize patients' expectations about course and outcomes or (b) supportive therapy, containing the same amount of therapeutic attention, but without specifically focusing on expectations. Postoperative plasma adrenaline, noradrenaline, and cortisol levels were a secondary outcome of our study (primary outcome patients' disability 6 months after surgery and other secondary patient-reported or clinical outcomes were reported elsewhere).

RESULTS

Expectation manipulation intervention (3.68 ln pg/mL, 95% confidence interval = 3.38-3.98, p = .015) and supportive therapy (3.70 ln pg/mL, 95% confidence interval = 3.38-4.01, p = .026) led to significantly lower postoperative adrenaline levels compared with SMC (4.26 ln pg/mL, 95% confidence interval = 3.99-4.53) only. There were no treatment effects of the preoperative intervention for noradrenaline (p = .90) or cortisol (p = .30). Higher postoperative adrenaline levels predicted disability 6 months after surgery (r = .258, p = .018).

CONCLUSIONS

In addition to SMC, preoperative psychological interventions seem to buffer psychobiological stress responses and could thus facilitate recovery from CABG surgery. Patients' postoperative stress responses could be an important factor for explaining trajectories of long-term outcomes.

CLINICAL TRIAL REGISTRATION

www.clinicaltrials.gov(NCT01407055).

Effect of Vitamin C on adrenal suppression by etomidate induction in patients undergoing cardiac surgery: A randomized controlled trial

Introduction:

Etomidate is usually preferred in the induction of cardiac compromised patients due to its relative cardiovascular stability. However, the use of this drug has been limited as etomidate induces suppression of cortisol biosynthesis as a result of blockade of 11-beta-hydroxylation in the adrenal gland, mediated by the imidazole radical of etomidate. This study was carried out to observe the effect of Vitamin C on adrenal suppression after etomidate induction in patients undergoing cardiac surgery.

Materials and Methods:

A total of 78 patients were randomly distributed into two groups. Group-I received oral Vitamin C (500 mg) twice daily and Group-II received antacid tablet as placebo twice daily instead of Vitamin C for 7 consecutive days prior to surgery till morning of surgery. Patients of both the groups induced with etomidate (0.1–0.3 mg/kg). Blood cortisol was estimated at different points of time till 24^th postinduction hour/blood lactate, glucose, hemodynamic parameters, and perioperative outcomes were assessed.

Results:

Data of seventy patients (n = 35 in each group) were finally analyzed. Cortisol level is statistically significantly higher in Group-I (69.51 ± 7.65) as compared to Group-II (27.74 ± 4.72) (P < 0.05) in the 1^st postinduction hour. In Group-II, cortisol was consistently lower for 1^st 24 postinduction hour. Total adrenaline requirement was statistically significantly high in Group-II. Time of extubation, length of Intensive Care Unit stay arrhythmia was similar in both the groups.

Conclusion:

Vitamin C effectively inhibits etomidate-induced adrenal suppression in cardiac patients, thereby etomidate can be used as a safe alternative for induction in cardiac surgery under cardiopulmonary bypass when pretreated with Vitamin C.

Early illness experiences related to unexpected heart surgery: A qualitative descriptive study

BACKGROUND

Most studies on patients' experiences following emergency cardiac surgery focus on evaluation of patients after their discharge. Few studies have evaluated patients' experiences after being transferred from intensive care and before being discharged.

OBJECTIVE

This study aimed to describe patients' experiences in the early stages of recovery following emergency heart surgery.

METHODS

For this exploratory qualitative descriptive study, 13 patients were recruited from a medical centre in northern Taiwan. Participants had undergone emergency heart surgery and had resided in the cardiothoracic surgical ward for ≥6 days following transfer from the ICU; all expected to be discharged from the hospital within 3 days. Semi-structured, face-to-face interviews were conducted in private after the patients had been transferred to the cardiothoracic surgical wards. Audiotaped interviews were transcribed and analysed using content analysis.

FINDINGS

Data analysis identified four themes, which represented different recovery stages: sudden and serious symptoms, nightmares and vivid dreams, physical and emotional disturbances, and establishing a new life after emergency surgery. A fifth theme, support for a new lifestyle, occurred between the four stages.

CONCLUSION

Participants experienced symptoms of physical and psychological stress during the early recovery stages following emergency heart surgery. A lack of understanding of the process of recovery increased these difficulties; participants wanted and needed multidisciplinary care and education. Emergency heart surgery does not allow healthcare professionals to inform patients of what to expect post-surgery. Our findings suggest that rather than waiting until discharge to offer disease information and treatment plans, multidisciplinary care should be initiated as soon as possible to facilitate recovery.

Pediatric Perioperative Stress Responses and Anesthesia

Surgical stress responses cause an array of endocrinological, metabolic and immunological changes in patients. The landmark studies in the 1980s showed that adequate anesthesia dramatically improved the outcomes of pediatric surgical patients by attenuating stress hormonal responses, pointing out the harm of 'inadequate' anesthesia. Subsequent studies questioned the role of administering very high-dose anesthetics to further attenuate stress responses. Here we review the feature of surgical stress responses in pediatric patients including their difference from those in adult patients. Overall, pediatric patients show minimal or no resting energy expenditure change postoperatively. In adult patients, increased resting energy expenditure has been described. Pediatric patients demonstrated robust cortisol and catecholamine responses than adult patients. However, the duration of these surges is often short-lived. Systemic proinflammatory and anti-inflammatory cytokine levels have been measured. Pediatric patients showed less proinflammatory cytokine elevation, but had similar anti-antiinflamatory responses. We also review in detail the immunological changes in response to surgical stress. Based on our current knowledge, we attempted to understand the underlying mechanism how adequate anesthesia dramatically improved the outcome of patients. Although more work is needed to be done, understanding how pediatric patients respond to perioperative stress, and its mechanism and consequence will allow us to direct us into a better, perioperative management in this population.

Comparing the Effects of Isoflurane-Sufentanil Anesthesia and Propofol-Sufentanil Anesthesia on Serum Cortisol Levels in Open Heart Surgery with Cardiopulmonary Bypass

Background

Major surgeries such as open-heart surgery with cardiopulmonary bypass are associated with a complexity of stress response leading to post-operative complications. Studies have confirmed that anesthesia can mitigate the surgically induced stress response.

Objectives

The aim of this study was to compare the effects of propofol and isoflurane, both supplemented with Sufentanil, on the stress response in coronary artery bypass graft surgery with cardiopulmonary bypass, using cortisol as a biochemical marker.

Methods

This double-blind randomized clinical trial was conducted on 72 patients who underwent coronary artery bypass grafting (CABG) with cardiopulmonary bypass meeting the inclusion criteria. The subjects were randomly divided into two groups of isoflurane (n = 36) and propofol (n = 36) both supplemented with sufentanil. Serum cortisol levels were measured and compared between the groups; 30 minutes before the surgery (T0), at the end of the cardiopulmonary bypass (T1), and 24 hours after the surgery (T2).

Results

Compared to the baseline (T0), at the end of cardiopulmonary bypass (T1), both groups demonstrated a decrease in plasma cortisol levels with no statistical significant difference (P = 0.4). At T2 measuring time point, the level of plasma cortisol significantly increased in both groups (P = 0.02), however this increase was less in the Isoflurane group.

Conclusions

In CABG with cardiopulmonary bypass, using plasma cortisol level as a measure, Isoflurane-Sufentanil significantly reduces the stress response to the surgery, when compared to propofol-Sufentanil.

Mind injuries after cardiac surgery

After cardiac surgery, delirium, cognitive dysfunction, depression, or anxiety disorders frequently occur, and profoundly affect patients' prognosis and quality of life. This narrative review focuses on the main clinical presentations of cognitive and psychological problems ('mind injuries') that occur postoperatively in absence of ascertainable focal neurologic deficits, exploring their pathophysiological mechanisms and possible strategies for prevention and treatment. Postoperative cognitive dysfunction is a potentially devastating complication that can involve several mechanisms and several predisposing, intraoperative, and postoperative risk factors, which can result in or be associated to cerebral microvascular damage. Postoperative depression is influenced by genetic or psychosocial predisposing factors, by neuroendocrine activation, and by the release of several pro-inflammatory factors. The net effect of these changes is neuroinflammation. These complex biochemical alterations, along with an aspecific response to stressful life events, might target the function of several brain areas, which are thought to represent a trigger factor for the onset of depression.

Effects of Low-dose Selenium on the Inflammatory Response in Coronary Artery Bypass Graft Surgery: A Clinical Trial

Background

Coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB) triggers an inflammatory reaction, leading to the development of myocardial damage and dysfunction. It is suggested that selenium (Se), an essential trace element, has a protective role against oxidative stress. Decreased intraoperative Se levels might be an independent predictive factor for postoperative multiorgan failure. In spite of its proposed advantages, however, the optimal timing and dosage are not well known.

Objectives

To determine whether 600 µg of intravenous Se administration before induction of anesthesia for CABG surgery could attenuate inflammatory reactions in an Iranian population.

Methods

This randomized triple-blind clinical trial took place in the department of cardiac surgery of an academic hospital affiliated with Guilan University of Medical Sciences (GUMS) from May 2015 to September 2015. Eighty-eight eligible patients scheduled for elective on-pump CABG surgery were divided into two groups using randomized fixed quadripartite blocks. They received either an intravenous bolus of 600 µg Se before induction of anesthesia, or normal saline as a placebo. We had four measurement time-points: just before induction of anesthesia (T0), immediately after the end of CPB (T1), 24 hours after surgery (T2), and 48 hours after surgery (T3). Interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP) serum levels were measured using the enzyme-linked immunosorbent assay (ELISA).

Results

Data from a total of 81 patients were analyzed: group S (n = 41) and group C (n = 40). There was no significant difference between the two groups with regard to baseline characteristics. In both groups, CPB caused markedly increased IL-6, TNF-α, and CRP plasma concentrations compared with baseline (P = 0.0001). However, the pattern of changes was not significantly different between group S (P = 0.068) and group C (P = 0.26). The IL-6 and TNF-α change trends were significant in each group (P=0.0001). However, comparing the two groups showed no significant difference. With regard to IL-6, there was no significant difference between the two groups at the time-points of T1 (P = 0.34), T2 (P = 0.17), and T3 (P = 0.056), and the same was found for TNF-α at T1 (P = 0.34), T2 (P = 0.17), and T3 (P = 0.056). With regard to CRP, the trend of the changes was significant in each group (P = 0.0001). However, comparing two groups showed a borderline significant difference between them at T1 (P = 0.039), but not at T2 (P = 0.075) or T3 (P = 0.11).

Conclusions

This study revealed that the administration of 600 μg of intravenous Se immediately before induction of anesthesia was safe, but when compared to a placebo, no predominant clinical effects or modifications in the systemic inflammatory response induced by on-pump CABG were observed.

Serum cortisol and early postoperative outcome after stage-1 palliation for hypoplastic left heart syndrome

OBJECTIVES

The postoperative cortisol profile and its association with early outcomes are poorly understood in neonates undergoing surgery for complex congenital heart disease. We investigated the postoperative profile of cortisol and its relationship with the clinical course in a cohort of newborns after stage-1 palliation for hypoplastic left heart syndrome.

DESIGN

Prospective observational study.

SETTING

Pediatric cardiovascular ICU at a tertiary children's hospital.

SUBJECTS

Twenty-three neonates after stage-1 palliation for hypoplastic left heart syndrome between 2009 and 2011.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Three serial measurements of total serum cortisol after surgery. The first measurement was taken immediately after surgery and the second and third-on the first and second postoperative mornings. The median weight of the infants was 3.0 kg (2.7-3.4 kg), and the age at surgery was 7 days (6-9 d). The median (25th-75th percentile) cortisol levels at admission, day 1, and day 2 were 96.2 μg/dL (51.1-112 μg/dL), 17.3 μg/dL (9.7-25.1 μg/dL), and 10 μg/dL (6.5-17 μg/dL), respectively (p < 0.0001 between admission and day 1). Higher cortisol was associated with greater morbidity, including the need for preoperative ventilation, increased total duration of ventilation, duration of inotropic support, and hospital length of stay.

CONCLUSIONS

Cortisol levels fell significantly over the first 24 hours after stage-1 palliation for hypoplastic left heart syndrome. A higher postoperative cortisol was associated with increased postoperative morbidity, which warrants further investigation.

An exploratory study of the patients' sleep patterns and inflammatory response following cardiopulmonary bypass (CPB)

AIMS AND OBJECTIVES

To describe sleep patterns and inflammatory response postCPB, determine sleep pattern changes and inflammatory response over time and explore relationships between sleep and biomarkers of stress and inflammation.

BACKGROUND

Despite the numerous citations of the role of sleep in restoration and health maintenance, a paucity of research exists about this phenomenon in patients undergoing CPB. Specifically, there is no research that has explored correlations between sleep patterns and systemic inflammatory response in adult cardiac surgery patients.

DESIGN

Exploratory, repeated-measures, correlational study.

METHOD

Subjects were recruited from a Midwestern urban hospital. Of the 25 eligible subjects, 16 males and four females completed the study. Wrist actigraphy was used to measure sleep variables. Salivary cortisol and C-reactive protein (C-RP) levels were measured daily. Data were collected during postoperative nights/days 1 through 4 (T1-T4).

RESULTS

Subjects' sleep onset latency (SOL) median scores (0 minute) were within normal range across time periods, whereas median scores for wake after sleep onset (WASO > 270 minutes), sleep fragmentation index (SFI >51%), total sleep time (<153 minutes) and sleep efficiency index (SEI <36%) fell outside the normal ranges. Changes in the median sleep scores over time, however, were not significant at p > 0·05. Median cortisol levels were within normal range (0·3-0·8 μg/dl) from T1-T4, but the C-RP level peaked at T2 (median = 2370 pg/ml). Strong correlations were found: (1) between SFI-cortisol (rs = 0·82), C-RP (rs = 0·65) - WBC (rs = 0·69); (2) between SEI-C-RP (rs = 0·58); (3) between WASO-WBC (rs = 0·48), WASO and cross-clamp time (rs = 0·50); and (4) between SOL-age (rs = -0·55) at p < 0·05.

CONCLUSIONS

Subjects were severely sleep-deprived with inflammatory response exaggerations warranting further investigations using larger sample sizes.

RELEVANCE TO CLINICAL PRACTICE

This study offers a foundation for developing a conceptual model explaining mechanisms of sleep disturbance and inflammatory response postCPB. This knowledge is crucial for testing sleep-promoting interventions to modulate inflammatory responses essential for preventing complications, and restoring health.

High postoperative serum cortisol level is associated with increased risk of cognitive dysfunction early after coronary artery bypass graft surgery: a prospective cohort study

Context

Stress response induced by surgery is proposed to play an important role in the pathogenesis of postoperative cognitive dysfunction.

Objective

To investigate the association between postoperative serum cortisol level and occurrence of cognitive dysfunction early after coronary artery bypass graft surgery.

Design

Prospective cohort study.

Setting

Two teaching hospitals.

Patients

One hundred and sixth-six adult patients who were referred to elective coronary artery bypass graft surgery from March 2008 to December 2009.

Intervention

None.

Main Outcome Measures

Neuropsychological tests were completed one day before and seven days after surgery. Cognitive dysfunction was defined using the same definition as used in the ISPOCD1-study. Blood samples were obtained in the first postoperative morning for measurement of serum cortisol concentration. Multivariate Logistic regression analyses were performed to assess the relationship between serum cortisol level and occurrence of postoperative cognitive dysfunction.

Results

Cognitive dysfunction occurred in 39.8% (66 of 166) of patients seven days after surgery. Multivariate Logistic regression analysis showed that high serum cortisol level was significantly associated with the occurrence of postoperative cognitive dysfunction (odds ratio [OR] 2.603, 95% confidence interval [CI] 1.371-4.944, P = 0.003). Other independent predictors of early postoperative cognitive dysfunction included high preoperative New York Heart Association functional class (OR 0.402, 95% CI 0.207-0.782, P = 0.007), poor preoperative Grooved Pegboard test score of nondominant hand (OR 1.022, 95% CI 1.003-1.040, P = 0.020), use of penehyclidine as premedication (OR 2.565, 95% CI 1.109-5.933, P = 0.028), and occurrence of complications within seven days after surgery (OR 2.677, 95% CI 1.201-5.963, P = 0.016).

Conclusions

High serum cortisol level in the first postoperative morning was associated with increased risk of cognitive dysfunction seven days after coronary artery bypass graft surgery.

The postoperative cortisol stress response following transsphenoidal pituitary surgery: a potential screening method for assessing preserved pituitary function

The ability to reliably identify patients with new hypocortisolemia acutely following pituitary surgery is critical. We aimed to quantify the postoperative cortisol stress response following selective transsphenoidal adenomectomy, as a marker for postoperative preservation of functional pituitary gland. Records of 208 patients undergoing transsphenoidal operations for pituitary lesions were reviewed. Patients with Cushing's Disease, preoperative adrenal insufficiency, and those receiving intraoperative steroids were excluded. To quantify the postoperative stress response, the ∆ cortisol index was defined as the postoperative day (POD) 1 morning cortisol minus the preoperative morning cortisol level. The incidence of new hypocortisolemia requiring glucocorticoid replacement upon hospital discharge was also recorded. Fifty-two patients met inclusion criteria. The mean preoperative, POD1, and POD2 cortisol levels were 16.5, 29.2, and 21.8 μg/dL, respectively. Morning fasting cortisol levels on POD1 ranged from 4.2 to 73.0 μg/dL. The ∆ cortisol index ranged from -19.0 to +56.2 (mean +12.7 μg/dL). Five patients (9.6%) developed new hypocortisolemia on POD 1-3 requiring glucocorticoid replacement; only one required long-term replacement. The mean ∆ cortisol in patients requiring postoperative glucocorticoids was -2.8 μg/dL, compared with +14.4 μg/dL in patients without evidence of adrenal insufficiency (p = 0.005). Of the 32 patients (61.5%) with a ∆cortisol >25 μg/dL, none developed postoperative adrenal insufficiency. The postoperative cortisol stress response, as quantified by the ∆ cortisol index, holds potential as a novel and complimentary screening method to predict preservation of normal pituitary function and acute development of new ACTH deficiency following transsphenoidal pituitary surgery.

Plasma leptin levels increase to a greater extent following on-pump coronary artery surgery in type 2 diabetic patients than in nondiabetic patients

AIMS

We aimed to evaluate whether leptin and ghrelin responses to cardiopulmonary bypass (CPB) are dependent on type 2 diabetes and whether these responses are associated with interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP), cortisol and insulin.

METHODS

We examined stress-response patterns in plasma leptin, ghrelin, hsCRP, IL-6, cortisol and insulin levels before and up to 5 days after cardiopulmonary bypass in 20 patients with type 2 diabetes and 20 patients without diabetes.

RESULTS

Plasma leptin levels increased significantly in both groups (p<0.05) and rose significantly higher in diabetics when compared with nondiabetic patients (p=0.004). Plasma ghrelin levels increased significantly only in diabetics (p=0.033). Patients with and without diabetes showed significantly elevated serum concentrations of IL-6, hsCRP, cortisol and insulin (p<0.005 for IL-6, hsCRP; p<0.05 for cortisol, insulin) but the difference between the two groups was nonsignificant. Leptin was independently predicted by hsCRP (p<0.05, F=2.9), gender (women p<0.001, F=4.7), body mass index (BMI p<0.0001, F=6.1) whereas ghrelin levels were not associated with any variables in the total patient population. (critical F=2.26, p≤0.05).

CONCLUSIONS

Acute phase response in diabetics differs by higher leptin levels independent of BMI, gender and IL-6, hsCRP, insulin and cortisol levels.

The adipocyte-derived hormone leptin has proliferative actions on androgen-resistant prostate cancer cells linking obesity to advanced stages of prostate cancer

Background. Because obesity may be a risk factor for prostate cancer, we investigated proliferative effects of adipocytes-derived hormone leptin on human prostate cancer cells and assessed the role of mitogen-activated protein kinase (MAPK) signaling pathway in mediating these actions. Material and Methods. Three human prostate cancer cell lines were treated with increasing doses of recombinant leptin. Cell growth was measured under serum-free conditions using a spectrophotometric assay. Further, Western blotting was applied to detect the phosphorylation of an ERK1/2, and a specific inhibitor of MAPK (PD98059; 40 μM) was used. Results. In both androgen-resistant cell lines DU145 and PC-3, cell growth was dose-dependently increased by leptin after 24 hrs and 48 hrs of incubation, whereas leptin's proliferative effects on androgen-sensitive cell line LNCaP was less pronounced. Further, leptin caused dose-dependent ERK1/2 phosphorylation in both androgen-resistant cell lines, and pretreatment of these cells with PD98059 inhibited these responses. Conclusions. Leptin may be a potential link between obesity and risk of progression of prostate cancer. Thus, studies on leptin and obesity association to prostate cancer should differentiate patients according to androgen sensitivity.

Adrenal insufficiency in cardiothoracic patients: an evaluation of the corticotrophin stimulation test and other diagnostic methods

PURPOSE

The purposes of the study were to determine the incidence of adrenal insufficiency (AI) using several published techniques, compare the response rates using a low-dose (LD) corticotropin (ACTH) stimulation test vs a standard dose (SD), and identify the technique that is most closely related to vasopressor use.

MATERIALS AND METHODS

Consecutive adult patients who were undergoing open heart surgery for CAD or valvular disease were prospectively enrolled. Exclusion criteria included history of steroid use, operative steroid, or etomidate administration. Postoperatively, each patient underwent ACTH stimulation with 1 μg (LD) and 249 μg (SD), 60 minutes apart. Agreement among the tests was evaluated, and vasopressor use was compared between groups.

RESULTS

There were 40 patients evaluated. The incidence of AI based on operative change, postoperative values, and LD-ACTH and SD-ACTH tests was 53%, 38%, 60%, and 38%, respectively. Agreement between the LD- and SD-ACTH tests was 73% (κ = 0.476, P = .001). There was a significant difference in the need for (93% vs 52%, P = .013) and duration (18.9 [0-180.6] vs 0.6 [0-73.2] hours, P = .003) of vasopressor therapy in patients with and without AI but only using the SD-ACTH definition.

CONCLUSION

The incidence of AI will vary greatly based on technique used for diagnosis. The SD-ACTH stimulation test should be used to determine AI in open heart patients postoperatively because of the close association with vasopressor usage.

Hemodynamic correlates of serum cortisol in neonates after cardiopulmonary bypass

OBJECTIVES

To document preoperative and early postoperative serum cortisol levels among a group of neonates with complex congenital heart disease undergoing cardiopulmonary bypass surgery and to describe the relationship between serum cortisol and hemodynamic variables in the early postoperative period.

DESIGN

Prospective observational substudy conducted within a randomized controlled trial.

SETTING

Tertiary-care pediatric cardiac intensive care unit.

PATIENTS

: We consecutively enrolled neonates undergoing a modified Norwood procedure or repair of interrupted aortic arch with ventricular septal defect in a randomized, placebo-controlled trial of triiodothyronine replacement. Methylprednisolone (30 mg/kg intravenously) was administered at anesthetic induction.

MEASUREMENTS AND MAIN RESULTS

We measured serum cortisol preoperatively and at 24 and 48 hrs postoperatively. Atrial filling pressures were documented 24 and 48 hrs after surgery. Oxygen consumption was measured and cardiac index was calculated 48 hrs after surgery. Spearman's correlation and linear regression were used to examine the relationship between serum cortisol and postoperative variables. Thirty-eight patients met eligibility criteria. Median serum cortisol levels 24 and 48 hrs postoperatively were 5.0 μg/dL (range 0.4-74.0) and 4.0 μg/dL (range 0.3-17.0), respectively (p = not significant). Greater atrial filling pressures were correlated with higher serum cortisol levels 24 hrs (r = .42, p = .019) and 48 hrs (r = .46, p = .022) after surgery. A lower cardiac index was correlated with higher serum cortisol levels 48 hrs postoperatively (r = -.49, p = .039), and this relationship remained significant after controlling for inotrope score, treatment with triiodothyronine, and atrial filling pressure in bivariate models. Systolic and diastolic BP did not correlate with serum cortisol at 24 or 48 hrs.

CONCLUSIONS

Serum cortisol levels were low in the majority of subjects, although a wide range was observed. Higher cortisol levels were associated with greater atrial filling pressures and a lower cardiac index. The relationship between serum cortisol and cardiovascular performance after cardiopulmonary bypass in infants warrants further evaluation.

Adrenal insufficiency in hemodynamically unstable neonates after open-heart surgery

OBJECTIVE

To investigate if the low dose (1 µg) ACTH stimulation test appropriately assesses adrenal responsiveness in neonates undergoing open-heart surgery requiring cardio-pulmonary bypass.

DESIGN

In this retrospective study, adrenal axis response was assessed on the first post-operative day with the low-dose (1 µg) ACTH stimulation test. Age, gender, weight, RACHS category, inotrope score, and baseline and post-stimulation cortisol levels were collected. The association between basal serum cortisol levels and degree of response to the ACTH stimulation test was also investigated.

SETTING

Tertiary care referral center.

PATIENTS

Twenty-one neonates who underwent neonatal cardiac surgery on cardiopulmonary bypass and underwent an ACTH stimulation test. Interventions.  Hydrocortisone 50 mg/m(2) bolus in four divided doses daily.

OUTCOME MEASURES

Response to the low dose (1 µg) ACTH stimulation was assessed.

RESULTS

All neonates with hemodynamic instability in the immediate post-operative period had low basal serum cortisol levels. The basal mean serum cortisol level for the 21 patients who underwent the low dose ACTH stimulation test was 7.3 µg/dL (median 2.2, range 0.7-42). The mean serum cortisol level increased after the ACTH stimulation test in the 21 patients to 39.6 µg/dL (median 38, range 79-17). The mean inotrope score in the first 24 hours after surgery was 24 (median 17.5, range 7-76.5) and decreased to 17 (median 14, range 5-52.3) 24-48 hours after surgery. At 48 hours post-surgery the mean arterial pressure in the groups with a serum cortisol increase after ACTH stimulation (<30 µg/dL vs. >50 µg/dL) was significantly different (P value 0.026).

CONCLUSIONS

The low dose (1 µg) ACTH stimulation test is a valid test to assess adrenal responsiveness among neonates after open heart surgery requiring CPB. Traditionally used basal serum cortisol level cutoff of <20 µg/dL used to define relative adrenal insufficiency may not be applicable in neonates undergoing open heart surgery on CPB thus indicating the need for re-defining adrenal insufficiency in this patient population.

High serum cortisol level is associated with increased risk of delirium after coronary artery bypass graft surgery: a prospective cohort study

Introduction

The pathophysiology of postoperative delirium remains poorly understood. The purpose of this study was to examine the relationship between serum cortisol level and occurrence of early postoperative delirium in patients undergoing coronary artery bypass graft (CABG) surgery.

Methods

A total of 243 patients undergoing elective CABG surgery were enrolled. Patients were examined twice daily during the first five postoperative days and postoperative delirium was diagnosed by using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). Blood samples were obtained between 7 a.m. and 8 a.m. on the first postoperative day and serum cortisol concentrations were then measured. Multivariate logistic regression analyses were performed to identify risk factors of postoperative delirium.

Results

Postoperative delirium occurred in 50.6% (123 of 243) of patients. High serum cortisol level was significantly associated with increased risk of postoperative delirium (OR 3.091, 95% CI 1.763-5.418, P < 0.001). Other independent risk factors of postoperative delirium included increasing age (OR 1.111, 95% CI 1.065-1.159, P < 0.001), history of diabetes mellitus (OR 1.905, 95% CI 1.001-3.622, P = 0.049), prolonged duration of surgery (OR 1.360, 95% CI 1.010-1.831, P = 0.043), and occurrence of complications within the first day after surgery (OR 2.485, 95% CI 1.184-5.214, P = 0.016). Patients who developed postoperative delirium had a higher incidence of postoperative complications and a prolonged duration of postoperative ICU and hospital stay.

Conclusions

Delirium was a common complication after CABG surgery. High serum cortisol level was associated with increased risk of postoperative delirium. Patients who developed delirium had outcomes worse than those who did not.

Leptin and the post-operative inflammatory response. More insights into the correlation with the clinical course and glucocorticoid administration

BACKGROUND

Cardiac surgery involving cardiopulmonary bypass (CPB) causes a systemic inflammatory process which can lead to multiple organ failure and postoperative morbidity. Recent animal and human studies suggested a possible involvement of leptin in the systemic inflammatory response.

AIM

To characterize the response of leptin to open heart surgery (OHS) and the relationship between the time course of leptin levels and the post-operative clinical course, and to examine the effect of exogenous glucocorticoids.

PATIENTS AND METHODS

Forty-seven pediatric patients, undergoing OHS for congenital heart disease were studied. Thirty-four patients (Group 1) received methylprednisolone during CPB while 13 (group 2) did not. Serial blood samples were collected perioperatively and up to 24 h after surgery, and assayed for leptin and cortisol.

RESULTS

All patients' leptin levels decreased significantly during CPB (to 44-48% of baseline, p<0.001); they then increased, peaking at 12 h post-operatively. The levels of groups 1 and 2 were similar up to 8 h post-operatively; thereafter, those of group 1 were significantly higher. Recovery of leptin levels in patients with a more complicated post-operative course was comparatively slower. Cortisol levels of all patients increased significantly during CPB (p<0.001), gradually decreasing afterwards. Cortisol and leptin levels were inversely correlated in both patients' groups.

CONCLUSIONS

CPB is associated with acute changes in circulating leptin levels. A complicated postoperative course is associated with lower leptin levels which are inversely correlated with cortisol levels. Leptin may participate in post-CPB inflammatory and hemodynamic responses.

The experience of stress for open heart surgery patients and their caregivers

The purpose of this research was to understand the modern experience of stress among adult coronary artery bypass grafting (CABG) patients who are hospitalized less than 10 days and among their significant caregivers. The naming of stressors and the nature and triggers for the stress response that either contributed to or ameliorated stress were examined. A qualitative research method using hermeneutic phenomenology was used to interpret and understand the experience of stress. The stressors identified by both patient and family participants in this study were shock and disbelief leading to a feeling of being overwhelmed. Among patients, mortality was foremost. Among family caregivers, anger was expressed. The importance of providing information, honesty, and trust were pivotal to alleviating stress. A more thorough knowledge of history and complementary therapies are needed to reduce stress.

Adipocytokine: a new family of inflammatory and immunologic markers of invasiveness in major urologic surgery

BACKGROUND

Laparoscopic surgery has been proposed to reduce surgical trauma and diminish patients' stress response.

OBJECTIVE

To investigate the role of the adipocytokine, in combination with changes in other known inflammatory markers, in patients undergoing radical prostatectomy.

DESIGN, SETTING, AND PARTICIPANTS

A total of 580 patients were enrolled in this prospective study. Laparoscopic extraperitoneal radical prostatectomy (LRP) was performed in 286 patients, and open retropubic radical prostatectomy (RRP) in 294 patients.

INTERVENTION

Blood samples were collected preoperatively and up to 5 d postoperatively.

MEASUREMENTS

Serum concentrations of acute phase markers, interleukins (IL), and the adipocytokine leptin were measured at each time point by means of enzyme-linked immunosorbent assay. Clinical data were collected and analysed.

RESULTS AND LIMITATIONS

Patients undergoing LRP had significantly lower IL-6 and adipocytokine levels at all measurement time points. However, biphasic kinetics of adipocytokine serum levels were observed during the postoperative course in all patients. LRP was associated with less adipocytokine and IL-6 release, indicating a smaller degree of surgical insult and the minimal invasive nature of this procedure. The limitation of this study was its nonrandomised design.

CONCLUSIONS

Adipocytokines might serve as additional immunologic markers of invasiveness in major urologic surgery.

Apical leptin induces chloride secretion by intestinal epithelial cells and in a rat model of acute chemotherapy-induced colitis

The purpose of this study was to investigate whether luminal leptin alters ion transport properties of the intestinal epithelium under acute inflammatory conditions. Monolayers of human intestinal T(84) epithelial cells and a rat model of chemotherapy-induced enterocolitis were used. Cells were treated with leptin and mounted in Ussing chambers to measure basal and secretagogue-induced changes in transepithelial short-circuit current (I(sc)). Furthermore, the role of MAPK and phosphatidylinositol 3-kinase (PI3K) signaling pathways in mediating responses to leptin was investigated. Acute colitis in Sprague-Dawley rats was induced by intraperitoneal injection of 40 mg/kg methotrexate. Leptin (100 ng/ml) induced a time-dependent increase in basal I(sc) in T(84) intestinal epithelial cells (P < 0.01). Moreover, pretreatment of T(84) cells with leptin for up to 1 h significantly potentiated carbachol- and forskolin-induced increases in I(sc). Pretreatment with an inhibitor of MAPK abolished the effect of leptin on basal, carbachol- and forskolin-induced chloride secretion (P < 0.05). However, the PI3K inhibitor, wortmannin, only blunted the effect of leptin on forskolin-induced increases in I(sc). Furthermore, leptin treatment evoked both ERK1/2 and Akt1 phosphorylation in T(84) cells. In the rat model, luminal leptin induced significant increases in I(sc) across segments of proximal and, to a lesser extent, distal colon (P < 0.05). We conclude that luminal leptin is likely an intestinal chloride secretagogue, particularly when present at elevated concentrations and/or in the setting of inflammation. Our findings may provide a mechanistic explanation, at least in part, for the clinical condition of secretory diarrhea both in hyperleptinemic obese patients and in patients with chemotherapy-induced intestinal inflammation.

Relative adrenal insufficiency and hemodynamic status in cardiopulmonary bypass surgery patients. A prospective cohort study

Background

The objectives of this study were to determine the risk factors for relative adrenal insufficiency in cardiopulmonary bypass patients and the impact on postoperative vasopressor requirements.

Methods

Prospective cohort study on cardiopulmonary bypass patients who received etomidate or not during anesthetic induction. Relative adrenal insufficiency was defined as a rise in serum cortisol ≤ 9 μg/dl after the administration of 250 μg of consyntropin. Plasma cortisol levels were measured preoperatively, immediately before, 30, 60, and 90 minutes after the administration of cosyntropin, and at 24 hours after surgery.

Results

120 elective cardiopulmonary bypass patients were included. Relative adrenal insufficiency (Δcortisol ≤9 μg/dl) incidence was 77.5%. 78 patients received etomidate and 69 (88%) of them developed relative adrenal insufficiency, (P < 0.001). Controlling for clinical characteristics with a propensity analysis, etomidate was the only independent risk factor associated with relative adrenal insufficiency (OR 6.55, CI 95%: 2.47-17.4; P < 0.001). Relative adrenal insufficiency patients showed more vasopressor requirements just after surgery (P = 0.04), and at 4 hours after surgery (P = 0.01). Pre and post-test plasma cortisol levels were inversely associated with maximum norepinephrine dose (ρ = -0.22, P = 0.02; ρ = -0.18, P = 0.05; ρ = -0.21, P = 0.02; and ρ = -0.22, P = 0.02, respectively).

Conclusions

Relative adrenal insufficiency in elective cardiopulmonary bypass patients may induce postoperative vasopressor dependency. Use of etomidate in these patients is a modifiable risk factor for the development of relative adrenal insufficiency that should be avoided.

Patterns and prognostic value of troponin, interleukin-6, and leptin after pediatric open-heart surgery

PURPOSE

Leptin and interleukin-6 (IL-6) are inversely correlated and associated with decreased survival in critically ill patients. We investigated changes in leptin, IL-6, and troponin in children undergoing open-heart surgery, hypothesizing that IL-6 and troponin will increase after cardiopulmonary bypass (CPB) and will be negatively correlated with leptin.

PATIENTS AND METHODS

Serial blood samples were collected from 21 patients 24 hours before and up to 48 hours after surgery.

RESULTS

Leptin levels decreased by 50% during CPB (P < .001), then gradually increased, reaching baseline levels 12 hours after surgery. The IL-6 levels increased (P < .001) during CPB, peaking 2 hours after surgery and remaining slightly elevated at 24 hours after surgery (P < .001). Leptin and IL-6 were negatively correlated (R = -0.448, P < .001). Troponin levels increased during CPB (P < .001). Postoperative leptin and troponin were inversely correlated (r = -0.535, P < .001). Patients with modest elevations in troponin levels (<20 microg/L) had a shorter aortic clamp and CPB time (P < .01), lower IL-6 peak levels (P = .03), and shorter duration of ventilation and inotropic support compared with patients with peak troponin levels greater than 20 microg/L.

CONCLUSIONS

Lower leptin and higher IL-6 levels correlated with troponin, a marker of myocardial injury. Because leptin may have cardioprotective effects, the postoperative drop in its levels may further contribute to myocardial dysfunction.

Acid-base effects of a bicarbonate-balanced priming fluid during cardiopulmonary bypass: comparison with Plasma-Lyte 148. A randomised single-blinded study

Fluid-induced metabolic acidosis can be harmful and can complicate cardiopulmonary bypass. In an attempt to prevent this disturbance, we designed a bicarbonate-based crystalloid circuit prime balanced on physico-chemical principles with a strong ion difference of 24 mEq/l and compared its acid-base effects with those of Plasma-Lyte 148, a multiple electrolyte replacement solution containing acetate plus gluconate totalling 50 mEq/l. Twenty patients with normal acid-base status undergoing elective cardiac surgery were randomised 1:1 to a 2 litre prime of either bicarbonate-balanced fluid or Plasma-Lyte 148. With the trial fluid, metabolic acid-base status was normal following bypass initiation (standard base excess 0.1 (1.3) mEq/l, mean, SD), whereas Plasma-Lyte 148 produced a slight metabolic acidosis (standard base excess -2.2 (2.1) mEq/l). Estimated group difference after baseline adjustment was 3.6 mEq/l (95% confidence interval 2.1 to 5.1 mEq/l, P=0.0001). By late bypass, mean standard base excess in both groups was normal (0.8 (2.2) mEq/l vs. -0.8 (1.3) mEq/l, P=0.5). Strong ion gap values were unaltered with the trial fluid, but with Plasma-Lyte 148 increased significantly on bypass initiation (15.2 (2.5) mEq/l vs. 2.5 (1.5) mEq/l, P < 0.0001), remaining elevated in late bypass (8.4 (3.4) mEq/l vs. 5.8 (2.4) mEq/l, P < 0.05). We conclude that a bicarbonate-based crystalloid with a strong ion difference of 24 mEq/l is balanced for cardiopulmonary bypass in patients with normal acid-base status, whereas Plasma-Lyte 148 triggers a surge of unmeasured anions, persisting throughout bypass. These are likely to be gluconate and/or acetate. Whether surges of exogenous anions during bypass can be harmful requires further study.

Does preoperative statin therapy improve outcomes in patients undergoing isolated cardiac valve surgery?

Preoperative statins have been associated with decreased mortality after coronary artery bypass grafting. Data are limited on whether these benefits extend to patients undergoing cardiac valve surgery. We examined whether preoperative statins decrease morbidity and mortality in patients undergoing isolated cardiac valve surgery. In a retrospective cohort analysis of consecutive patients who underwent surgical valve repair or replacement (excluding concomitant coronary artery bypass grafting, aortic root replacement, or ventricular assist device placement) at St. Luke's Episcopal Hospital, the primary outcome was 30-day mortality. Secondary outcomes included 30-day major adverse events (composite of early mortality, postoperative myocardial infarction, or stroke). Of 825 patients, 31% received preoperative statins (n = 255). Logistic regression analysis revealed that age >65 years (p = 0.02), history of congestive heart failure (p = 0.001), and total bypass time >80 minutes (p = 0.01) were independent predictors of increased 30-day mortality. Preoperative statin therapy was not associated with decreased 30-day mortality (odds ratio 0.89, 95% confidence interval 0.38 to 2.03), major adverse events (odds ratio 1.09, 95% confidence interval 0.61 to 1.96), postoperative myocardial infarction (p = 0.70), or stroke (p = 0.57). At a mean follow-up of 1.57 years, preoperative statin therapy was not associated with decreased mortality (p = 0.81). In the analysis using propensity score matching (354 propensity-matched patients, 177 in each group), preoperative statin was not associated with improved primary or secondary outcomes. In conclusion, preoperative statin therapy was not associated with a decrease in morbidity or mortality in patients undergoing isolated cardiac valve surgery.

Mitogenic and anti-apoptotic actions of adipocyte-derived hormone leptin in prostate cancer cells

OBJECTIVE

To investigate the proliferative and anti-apoptotic effects of leptin on human prostate cancer cells, and the role of related signalling pathways in mediating these actions, as obesity is a possible risk factor for prostate cancer and leptin, an adipocyte-derived hormone, has mitogenic action in various cell types.

MATERIALS AND METHODS

Two human prostate cancer cell lines, DU145 and PC-3, were treated with leptin (5-100 ng/mL) for up to 48 h. Under serum-free conditions, cell proliferation was measured using a colorimetric tetrazolium assay and apoptosis by an enzyme-linked immunosorbent assay measuring cell death. Also, the phosphorylation of ERK1/2 and Akt was detected by Western blotting, and specific inhibitors of mitogen-activated protein kinase (MAPK) (PD98059; 40 microm) and phosphatidylinositol 3-kinase (PI3-K, LY294002; 40 microm) were used to evaluate the role of these signalling pathways.

RESULTS

Leptin dose-dependently increased the cell number in both cell lines for up to 48 h of incubation, the mean (sem) percentage of the control being 189 (4.3)% for DU145 and 173 (7.5)% for PC-3 (100 ng/mL leptin, 48 h; P < 0.01). Leptin also significantly reduced the number of apoptotic cells after 24 h of treatment, dose-dependently caused ERK1/2 and Akt phosphorylation; pretreatment with inhibitors of MAPK and PI3-K inhibited these responses.

CONCLUSION

These results show that chronic increases in leptin might enhance the growth of prostate cancer via the MAPK and PI3-K pathways. Further studies are needed to investigate whether the ability of leptin to stimulate mitogenic/anti-apoptotic signal transduction pathways could represent a target for anticancer drug discovery.