Journal of Clinical Neuroscience 21 (2014) 2150–2154
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Clinical Study
Diurnal salivary cortisol measurement in the neurosurgical-surgical intensive care unit in critically ill acute trauma patients Viktor Bartanusz a,⇑, Michael G. Corneille b, Salvador Sordo c, Marianne Gildea c, Joel E. Michalek d, Prakash V. Nair d, Ronald M. Stewart c, Daniela Jezova e a
Department of Neurosurgery, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA Trauma Center, John C. Lincoln Mountain Hospital, Phoenix, AZ, USA Department of Surgery, University of Texas Health Science Center, San Antonio, TX, USA d Department of Epidemiology and Biostatistics, School of Medicine, University of Texas Health Science Center, San Antonio, TX, USA e Institute of Experimental Endocrinology, Slovak Academy of Sciences, Slovak Republic b c
a r t i c l e
i n f o
Article history: Received 13 February 2014 Accepted 22 April 2014
Keywords: Acute trauma Brain injury Circadian rhythm Critical care Hypothalamic-pituitary-adrenocortical axis Salivary cortisol
a b s t r a c t Acute trauma patients represent a specific subgroup of the critically ill population due to sudden and dramatic changes in homeostasis and consequently extreme demands on the activity of the hypothalamic-pituitary-adrenocortical (HPA) axis. Salivary cortisol is an accepted surrogate for serum free cortisol in the assessment of HPA axis function. The purpose of this study was (1) to establish the feasibility of salivary cortisol measurement in acute trauma patients in the neurosurgical–surgical intensive care unit (NSICU), and (2) to determine the diurnal pattern of salivary cortisol in the acute phase after injury. Saliva from 50 acute trauma patients was prospectively collected twice a day at 6AM and 4PM during the first week after injury in the NSICU. Mean PM cortisol concentrations were significantly higher in subjects versus controls (p < 0.001). Subjects failed to develop the expected PM versus AM decrease in cortisol concentration seen in controls (p = 0.005). Salivary cortisol did not vary significantly with baseline Glasgow Coma Scale (GCS), Injury Severity Score, sex, injury type, ethnicity, or age. When comparing mean AM and PM salivary cortisol by GCS severity category (GCS 68 and GCS >8) the AM salivary cortisol was significantly higher in patients with GCS 68 (p = 0.002). The results show a loss of diurnal cortisol variation in acute trauma patient in the NSICU during the first week of hospitalization. Patients with severe brain injury had higher morning cortisol levels than those with mild/moderate brain injury. Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction Dysfunction of the hypothalamic-pituitary-adrenocortical (HPA) axis with inadequate corticosteroid hormone secretion in critically ill patients may have deleterious consequences and therefore consensus recommendations for the diagnosis and management of corticosteroid insufficiency in these patients have been proposed [1–4]. Free plasma cortisol determination is the most appropriate reflection of HPA axis activity, but unfortunately the methodology of serum free cortisol determination is laborious, time consuming, and expensive, making access to timely measurements for clinical guidance infeasible [5–7]. Salivary cortisol is an accepted surrogate for serum free cortisol. It has a high degree of correlation with serum free cortisol levels as measured by equilibrium dialysis and its concentration in the saliva is independent of ⇑ Corresponding author. Tel.: +1 210 567 5625; fax: +1 210 567 6066. E-mail address: [email protected] (V. Bartanusz). http://dx.doi.org/10.1016/j.jocn.2014.04.018 0967-5868/Ó 2014 Elsevier Ltd. All rights reserved.
salivary flow rate [8–10]. Salivary cortisol measurements have been also used in the assessment of adrenal function in critically ill hospitalized patients [11–13]. Severely injured acute trauma patients represent a specific subgroup of the critically ill population due to sudden and dramatic changes in their homeostasis. Several previous studies have investigated neuroendocrine responses to injury including plasma cortisol measurements, but saliva collection and salivary cortisol determination in patients admitted to the intensive care unit following acute trauma has not been studied to our knowledge [14–19]. One of the significant obstacles of salivary cortisol measurement in critically ill intubated patients is the collection of a sufficient amount of clear saliva [13,20]. Therefore, the purpose of the present study was (1) to establish the feasibility of salivary cortisol measurement in intubated acute trauma patients in the neurosurgical–surgical intensive care unit (NSICU), and (2) to determine the diurnal pattern of salivary cortisol in the acute phase after injury.
V. Bartanusz et al. / Journal of Clinical Neuroscience 21 (2014) 2150–2154
2. Material and methods
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The sensitivity of the assay was 0.05 ng/ml. The intra-assay and inter-assay coefficient of variation was 4.2% and 9.3%, respectively.
2.1. Patient population and study design 2.4. Statistical methods This was a prospective, single center, pilot study including subjects at least 18 years old admitted to the NSICU for a period of at least 72 hours. Exclusion criteria were inability to obtain consent from the subject or the subject’s legally authorized representative prior to the subject’s hospital discharge, pregnancy, being a prisoner, suffering from a known or suspected active oral infection, currently enrolled in an investigational drug study, had previously been enrolled in this study, actively bleeding oral mucosa not anticipated to resolve within 72 hours, or oral care was prohibited due to a pathological situation or physician order. 2.2. Saliva sampling Saliva samples were collected at 6AM and 4PM during the first week after admission to the NSICU. Each subject’s mouth was rinsed with plain water 10 minutes prior to sample collection. Oral care by the bedside nurse utilizing toothpaste or other cleaning agents was avoided at least 1 hour prior to the samples being collected. From the start the original Salivette wads (Sarstedt, Nümbrecht, Germany) were replaced by four surgical patties with strings (Codman and Shurtleff, Raynham, MA, USA) (Fig. 1), which were placed in between the buccal mucosa and dentation, two on each side of the mouth. We considered the use of patties much safer in intubated patients with practically no risk of material retention in the mouth (Fig. 1). Surgical patties were left in place for 10 minutes then placed in the upper chamber of a Salivette tube and immediately centrifuged. Salivettes containing at least 200 uL of saliva were frozen for batch analysis. Healthy volunteer samples were collected at 6AM and 4PM in a 24 hour period. The Institutional Review Board approved the study, and informed written consent was obtained from healthy control subjects and patients or their legal guardians.
Binary and categorical outcomes were summarized with counts and percentages and continuously distributed outcomes with the mean ± one standard deviation and the median. Group contrasts (subjects versus controls) on salivary cortisol were conducted in original units (ng/ml) on within-subject salivary cortisol means (AM, PM) or within-subject differences of means (AM mean minus PM mean) across days with Wilcoxon tests. The significance of the relations between salivary cortisol and baseline Glasgow Coma Scale (GCS) score, Injury Severity Score (ISS), sex, age, injury type (blunt, penetrating), and ethnicity (Latino, non-Latino) were assessed with repeated measures linear models with adjustment for time of day. Correlations were computed in original units. All statistical testing was two-sided with a significance level of 5% and SAS version 9.2 (SAS Institute, Cary, NC, USA) was used throughout. Corrections for multiple testing were not applied. 3. Results We screened 783 patients admitted to the NSICU, and of these 715 were screen failures and 68 were enrolled (Fig. 2). Of the 68
2.3. Salivary cortisol determination Cortisol concentrations in saliva were measured using a commercial solid phase enzyme-linked immunosorbent assay (Cortisol ELISA, RE52611, IBL International, Hamburg, Germany).
Fig. 1. The original Salivette wads (Sarstedt, Nümbrecht, Germany) were replaced by surgical patties with strings (inset). Four surgical patties, two on each side, were placed in between the buccal mucosa and dentation.
Fig. 2. Consort diagram showing patient screening and enrollment failures. DNR = do not resuscitate, hr = hour, IC = informed consent, ICU = intensive care unit, yrs = years.
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Table 1 Number of successfully collected and processed saliva samples Total possible saliva collections from enrolled patients Causes for failure to collect or process saliva Patient discharge from ICU before the end of collection Patient refusal or patient not present in the time of collection Insufficient saliva volume or visible blood contamination Successfully collected and processed
750 (100%) 432 (57.6%) 256 (34.1%) 51 (6.8%) 125 (16.7%) 318 (42.4%)
enrolled, 18 were lost due to exclusion (for protocol changes [n = 5], withdrawal of consent by family [n = 6] or patient [n = 3]) or withdrawal (due to patient concerns about safety [n = 2], transfer [n = 1], and do not resuscitate [n = 1]). Thus, a total of 50 subjects completed the study. We also enrolled 26 normal healthy volunteers to serve as the control group. Covariate information was not available for controls (Fig. 2). Subjects were middle aged (mean age 49.5 ± 19.7 years), predominantly Caucasian and Hispanic (Black 4%, Hispanic 44%, Caucasian 52%), 92% had experienced blunt injury, the average ISS was 24.6 ± 10.7, and the average GCS was 10.3 ± 5.4. The possible number of saliva collections was 750 (50 subjects, each followed for 8 days with two measurements per day [AM and PM] for the first 7 days and one measurement [AM] on the eighth day]. In the NSICU, 256 (34.1%) samples were not obtained due to patient discharge before the end of the collection period. One hundred and twenty-five (16.7%) samples were not processed due to insufficient saliva volume or visible blood contamination, and 51 (6.8%) samples were not obtained because of patient refusal or patient not in room at prescribed time. Therefore, only 318 (42.4%) saliva samples could be successfully collected and processed (Table 1). Measurement of afternoon salivary cortisol levels in the subject group showed significantly higher median results than those in the control group (p < 0.001), but the two groups were similar with regard to morning salivary cortisol level (p = 0.48). The diurnal variability in salivary cortisol secretion was not present in the subject group and in contrast to controls there was no difference between AM and PM salivary cortisol values in subjects (Fig. 3). AM and PM salivary cortisol levels did not correlate significantly with ISS (AM: r = 0.08, p = 0.58; PM: r = 0.08, p = 0.59) and the diurnal cortisol change did not correlate with ISS (r = 0.05,
Fig. 3. Mean salivary cortisol by group and time of day (6AM, 4PM) showing the mean PM salivary cortisol was significantly increased in patients relative to controls.
p = 0.75). Salivary cortisol did not vary significantly with baseline GCS (p = 0.41), sex (p = 0.29), injury type (p = 0.58), or ethnicity (p = 0.20). The relation between salivary cortisol and age varied significantly with day (p = 0.007), most likely due to the apparent increase in mean salivary cortisol among older subjects (age >49 years) in the afternoon on days 3, 5, and 6. If this interaction with day is ignored, then the relation between salivary cortisol and age was not significant (p = 0.90). When comparing mean AM and PM salivary cortisol by GCS severity category (GCS 68 and GCS >8) the AM salivary cortisol was significantly higher in patients with GCS 68 compared to that in patients with GCS >8 (p = 0.002, Fig. 4A). Mean AM and PM salivary cortisol did not show significant variation with ISS severity category (ISS 8). AM salivary cortisol was significantly increased in patients with GCS 68. (B) Mean AM and PM salivary cortisol by Injury Severity Score (ISS) category (8) brain injured patients. Llompart-Pou et al. studied the acute HPA axis response in patients with traumatic brain injury with and without extracerebral trauma based on blood adrenocorticotropic hormone and cortisol levels between 24 and 48 hours after the trauma [18]. The study did not find any measurable difference in HPA axis responsiveness between the two groups [18]. Measurement of cortisol concentrations in saliva may be a more sensitive approach to reveal differences in HPA axis activity in relation to the severity of head injury. The most important limitation of our study is that morning and evening cortisol values do not necessarily reflect the subtle time and stressor specific functioning of the HPA axis. Therefore, multiple daily saliva samples and cortisol measurements would be preferable in the future and these should be correlated with the
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patient’s vital signs, medications, as well as exposure to interventions and transfers. Conflicts of Interest/Disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. Acknowledgments Sponsored by the Department of the Army, W81XWH-07-10717. The U.S. Army Medical research Acquisition Activity, 820 Chandler Street, Fort Detrick MD 21702-5014 is the awarding and administering acquisition office. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense. The analytical part of the study was supported by APVV-0028-10 and project of Centre of Excellence CEMAN. References [1] Annane D, Sébille V, Charpentier C, et al. Effect of treatment with low doses of hydrocortisone and fludrocortisone on mortality in patients with septic shock. JAMA 2002;288:862–71. [2] Cotton BA, Guillamondegui OD, Fleming SB, et al. Increased risk of adrenal insufficiency following Etomidate exposure in critically injured patients. Arch Surg 2008;143:62–7 [discussion 67]. [3] Sprung CL, Annane D, Keh D, et al. Hydrocortisone therapy for patients with septic shock. N Engl J Med 2008;358:111–24. [4] Marik PE, Pastores SM, Annane D, et al. Recommendations for the diagnosis and management of corticosteroid insufficiency in critically ill adult patients: consensus statements from an international task force by the American College of critical care medicine. Crit Care Med 2008;36:1937–49. [5] Hamrahian AH, Oseni TS, Arafah BM. Measurements of serum free cortisol in critically ill patients. N Engl J Med 2004;350:1629–38. [6] Arafah BM. Hypothalamic pituitary adrenal function during critical illness: limitations of current assessment methods. J Clin Endocrinol Metab 2006;91:3725–45. [7] Loriaux L. Glucocorticoid therapy in the intensive care unit. N Engl J Med 2004;350:1601–2. [8] Jezova D, Hlavacova N. Endocrine factors in stress and psychiatric disorders: focus on anxiety and salivary steroids. Ann N Y Acad Sci 2008;1148:495–503. [9] Kerlik J, Penesova A, Vlcek M, et al. Comparison of salivary cortisol and calculated free plasma cortisol during low-dose ACTH test in healthy subjects. Clin Biochem 2010;43:764–7. [10] Golden SH, Wand GS, Malhotra S, et al. Reliability of hypothalamic–pituitary– adrenal axis assessment methods for use in population-based studies. Eur J Epidemiol 2011;26:511–25. [11] Arafah BM, Nishiyama FJ, Tlaygeh H, et al. Measurement of salivary cortisol concentration in the assessment of adrenal function in critically ill subjects: a surrogate marker of circulating free cortisol. J Clin Endocrinol Metab 2007;92:2965–71. [12] Raff H, Brock S, Findling JW. Cosyntropin-stimulated salivary cortisol in hospitalized patients with hypoproteinemia. Endocrine 2008;34:68–74. [13] Mello RC, Sad EF, Andrade BC, et al. Serum and salivary cortisol in the diagnosis of adrenal insufficiency and as a predictor of the outcome in patients with severe sepsis. Arq Bras Endocrinol Metabol 2011;55:455–9. [14] Delahanty D, Nugent N. Predicting PTSD prospectively based on prior trauma history and immediate biological responses. Ann NY Acad Sci 2006;1071:27–40. [15] Delahanty D, Raimonde A, Spoonster E. Initial posttraumatic urinary cortisol levels predict subsequent PTSD symptoms in motor vehicle accident victims. Biol Psychiatry 2000;48:940–7. [16] Ehring T, Ehlers A, Cleare A, et al. Do acute psychological and psychobiological responses to trauma predict subsequent symptom severities and PTSD and depression? Psychiatry Res 2008;161:67–75. [17] McFarlane AC, Barton CA, Yehuda R, et al. Cortisol response to acute trauma and risk of posttraumatic stress disorder. Psychoneuroendocrinology 2011;36:720–7. [18] Llompart-Pou JA, Raurich JM, Pérez-Bárcena J, et al. Acute Hypothalamic– pituitary–adrenal response in traumatic brain injury with and without extracerebral trauma. Neurocrit Care 2008;9:230–6. [19] Wagner AK, McCullogh EH, Niyonkuru C, et al. Acute hormone levels: characterization and prognosis after severe traumatic brain injury. J Neurotrauma 2011;28:871–88. [20] Cohen J, Venkatesh B, Galligan J, et al. Salivary cortisol concentration in the intensive care population: correlation with plasma cortisol values. Anaesth Intensive Care 2004;32:843–5.
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[21] Dennesen P, van der Ven A, Vlasveld M, et al. Inadequate salivary flow and poor oral mucosal status in intubated intensive care unit patients. Crit Care Med 2003;31:781–6. [22] Aardal E, Holm AC. Cortisol in saliva – reference ranges and relation to cortisol in serum. Eur J Clin Chem Clin Biochem 1995;33:927–32. [23] Kivlighan KT, Granger DA, Schwartz E, et al. Quantifying blood leakage into the oral mucosa and its effects on the measurement of cortisol, dehydroepiandrosterone, and testosterone in saliva. Horm Behav 2004;46:39–46. [24] Granger DA, Cichetti D, Rogosch FA, et al. Blood contamination in children’s saliva: prevalence, stability, and impact on the measurement of salivary cortisol, testosterone, and dehydroepiandrosterone. Psychoneuroendocrinology 2007;32:724–33. [25] Riutta A, Ylitalo P, Kaukinen S. Diurnal variation of melatonin and cortisol is maintained in non-septic intensive care patients. Intensive Care Med 2009;35:1720–7.
[26] Savaridas T, Andrews PJ, Harris B. Cortisol dynamics following acute severe brain injury. Intensive Care Med 2004;30:1479–83. [27] Cohan P, Wang C, McArthur DL, et al. Acute secondary adrenal insufficiency after traumatic brain injury: a prospective study. Crit Care Med 2005;33:2358–66. [28] Llompart-Pou JA, Pérez G, Raurich JM, et al. Loss of cortisol circadian rhythm in patients with traumatic brain injury: a microdialysis evaluation. Neurocrit Care 2010;13:211–6. [29] Paul T, Lemmer B. Disturbance of circadian rhythms in analgosedated intensive care unit patients with and without craniocerebral injury. Chronobiol Int 2007;24:45–61. [30] Schwarz S, Schwab S, Klinga K, et al. Neuroendocrine changes in patients with acute space occupying ischemic stroke. J Neurol Neurosurg Psychiatry 2003;74:725–7.
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Clinical Study
Diurnal salivary cortisol measurement in the neurosurgical-surgical intensive care unit in critically ill acute trauma patients Viktor Bartanusz a,⇑, Michael G. Corneille b, Salvador Sordo c, Marianne Gildea c, Joel E. Michalek d, Prakash V. Nair d, Ronald M. Stewart c, Daniela Jezova e a
Department of Neurosurgery, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA Trauma Center, John C. Lincoln Mountain Hospital, Phoenix, AZ, USA Department of Surgery, University of Texas Health Science Center, San Antonio, TX, USA d Department of Epidemiology and Biostatistics, School of Medicine, University of Texas Health Science Center, San Antonio, TX, USA e Institute of Experimental Endocrinology, Slovak Academy of Sciences, Slovak Republic b c
a r t i c l e
i n f o
Article history: Received 13 February 2014 Accepted 22 April 2014
Keywords: Acute trauma Brain injury Circadian rhythm Critical care Hypothalamic-pituitary-adrenocortical axis Salivary cortisol
a b s t r a c t Acute trauma patients represent a specific subgroup of the critically ill population due to sudden and dramatic changes in homeostasis and consequently extreme demands on the activity of the hypothalamic-pituitary-adrenocortical (HPA) axis. Salivary cortisol is an accepted surrogate for serum free cortisol in the assessment of HPA axis function. The purpose of this study was (1) to establish the feasibility of salivary cortisol measurement in acute trauma patients in the neurosurgical–surgical intensive care unit (NSICU), and (2) to determine the diurnal pattern of salivary cortisol in the acute phase after injury. Saliva from 50 acute trauma patients was prospectively collected twice a day at 6AM and 4PM during the first week after injury in the NSICU. Mean PM cortisol concentrations were significantly higher in subjects versus controls (p < 0.001). Subjects failed to develop the expected PM versus AM decrease in cortisol concentration seen in controls (p = 0.005). Salivary cortisol did not vary significantly with baseline Glasgow Coma Scale (GCS), Injury Severity Score, sex, injury type, ethnicity, or age. When comparing mean AM and PM salivary cortisol by GCS severity category (GCS 68 and GCS >8) the AM salivary cortisol was significantly higher in patients with GCS 68 (p = 0.002). The results show a loss of diurnal cortisol variation in acute trauma patient in the NSICU during the first week of hospitalization. Patients with severe brain injury had higher morning cortisol levels than those with mild/moderate brain injury. Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction Dysfunction of the hypothalamic-pituitary-adrenocortical (HPA) axis with inadequate corticosteroid hormone secretion in critically ill patients may have deleterious consequences and therefore consensus recommendations for the diagnosis and management of corticosteroid insufficiency in these patients have been proposed [1–4]. Free plasma cortisol determination is the most appropriate reflection of HPA axis activity, but unfortunately the methodology of serum free cortisol determination is laborious, time consuming, and expensive, making access to timely measurements for clinical guidance infeasible [5–7]. Salivary cortisol is an accepted surrogate for serum free cortisol. It has a high degree of correlation with serum free cortisol levels as measured by equilibrium dialysis and its concentration in the saliva is independent of ⇑ Corresponding author. Tel.: +1 210 567 5625; fax: +1 210 567 6066. E-mail address: [email protected] (V. Bartanusz). http://dx.doi.org/10.1016/j.jocn.2014.04.018 0967-5868/Ó 2014 Elsevier Ltd. All rights reserved.
salivary flow rate [8–10]. Salivary cortisol measurements have been also used in the assessment of adrenal function in critically ill hospitalized patients [11–13]. Severely injured acute trauma patients represent a specific subgroup of the critically ill population due to sudden and dramatic changes in their homeostasis. Several previous studies have investigated neuroendocrine responses to injury including plasma cortisol measurements, but saliva collection and salivary cortisol determination in patients admitted to the intensive care unit following acute trauma has not been studied to our knowledge [14–19]. One of the significant obstacles of salivary cortisol measurement in critically ill intubated patients is the collection of a sufficient amount of clear saliva [13,20]. Therefore, the purpose of the present study was (1) to establish the feasibility of salivary cortisol measurement in intubated acute trauma patients in the neurosurgical–surgical intensive care unit (NSICU), and (2) to determine the diurnal pattern of salivary cortisol in the acute phase after injury.
V. Bartanusz et al. / Journal of Clinical Neuroscience 21 (2014) 2150–2154
2. Material and methods
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The sensitivity of the assay was 0.05 ng/ml. The intra-assay and inter-assay coefficient of variation was 4.2% and 9.3%, respectively.
2.1. Patient population and study design 2.4. Statistical methods This was a prospective, single center, pilot study including subjects at least 18 years old admitted to the NSICU for a period of at least 72 hours. Exclusion criteria were inability to obtain consent from the subject or the subject’s legally authorized representative prior to the subject’s hospital discharge, pregnancy, being a prisoner, suffering from a known or suspected active oral infection, currently enrolled in an investigational drug study, had previously been enrolled in this study, actively bleeding oral mucosa not anticipated to resolve within 72 hours, or oral care was prohibited due to a pathological situation or physician order. 2.2. Saliva sampling Saliva samples were collected at 6AM and 4PM during the first week after admission to the NSICU. Each subject’s mouth was rinsed with plain water 10 minutes prior to sample collection. Oral care by the bedside nurse utilizing toothpaste or other cleaning agents was avoided at least 1 hour prior to the samples being collected. From the start the original Salivette wads (Sarstedt, Nümbrecht, Germany) were replaced by four surgical patties with strings (Codman and Shurtleff, Raynham, MA, USA) (Fig. 1), which were placed in between the buccal mucosa and dentation, two on each side of the mouth. We considered the use of patties much safer in intubated patients with practically no risk of material retention in the mouth (Fig. 1). Surgical patties were left in place for 10 minutes then placed in the upper chamber of a Salivette tube and immediately centrifuged. Salivettes containing at least 200 uL of saliva were frozen for batch analysis. Healthy volunteer samples were collected at 6AM and 4PM in a 24 hour period. The Institutional Review Board approved the study, and informed written consent was obtained from healthy control subjects and patients or their legal guardians.
Binary and categorical outcomes were summarized with counts and percentages and continuously distributed outcomes with the mean ± one standard deviation and the median. Group contrasts (subjects versus controls) on salivary cortisol were conducted in original units (ng/ml) on within-subject salivary cortisol means (AM, PM) or within-subject differences of means (AM mean minus PM mean) across days with Wilcoxon tests. The significance of the relations between salivary cortisol and baseline Glasgow Coma Scale (GCS) score, Injury Severity Score (ISS), sex, age, injury type (blunt, penetrating), and ethnicity (Latino, non-Latino) were assessed with repeated measures linear models with adjustment for time of day. Correlations were computed in original units. All statistical testing was two-sided with a significance level of 5% and SAS version 9.2 (SAS Institute, Cary, NC, USA) was used throughout. Corrections for multiple testing were not applied. 3. Results We screened 783 patients admitted to the NSICU, and of these 715 were screen failures and 68 were enrolled (Fig. 2). Of the 68
2.3. Salivary cortisol determination Cortisol concentrations in saliva were measured using a commercial solid phase enzyme-linked immunosorbent assay (Cortisol ELISA, RE52611, IBL International, Hamburg, Germany).
Fig. 1. The original Salivette wads (Sarstedt, Nümbrecht, Germany) were replaced by surgical patties with strings (inset). Four surgical patties, two on each side, were placed in between the buccal mucosa and dentation.
Fig. 2. Consort diagram showing patient screening and enrollment failures. DNR = do not resuscitate, hr = hour, IC = informed consent, ICU = intensive care unit, yrs = years.
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V. Bartanusz et al. / Journal of Clinical Neuroscience 21 (2014) 2150–2154
Table 1 Number of successfully collected and processed saliva samples Total possible saliva collections from enrolled patients Causes for failure to collect or process saliva Patient discharge from ICU before the end of collection Patient refusal or patient not present in the time of collection Insufficient saliva volume or visible blood contamination Successfully collected and processed
750 (100%) 432 (57.6%) 256 (34.1%) 51 (6.8%) 125 (16.7%) 318 (42.4%)
enrolled, 18 were lost due to exclusion (for protocol changes [n = 5], withdrawal of consent by family [n = 6] or patient [n = 3]) or withdrawal (due to patient concerns about safety [n = 2], transfer [n = 1], and do not resuscitate [n = 1]). Thus, a total of 50 subjects completed the study. We also enrolled 26 normal healthy volunteers to serve as the control group. Covariate information was not available for controls (Fig. 2). Subjects were middle aged (mean age 49.5 ± 19.7 years), predominantly Caucasian and Hispanic (Black 4%, Hispanic 44%, Caucasian 52%), 92% had experienced blunt injury, the average ISS was 24.6 ± 10.7, and the average GCS was 10.3 ± 5.4. The possible number of saliva collections was 750 (50 subjects, each followed for 8 days with two measurements per day [AM and PM] for the first 7 days and one measurement [AM] on the eighth day]. In the NSICU, 256 (34.1%) samples were not obtained due to patient discharge before the end of the collection period. One hundred and twenty-five (16.7%) samples were not processed due to insufficient saliva volume or visible blood contamination, and 51 (6.8%) samples were not obtained because of patient refusal or patient not in room at prescribed time. Therefore, only 318 (42.4%) saliva samples could be successfully collected and processed (Table 1). Measurement of afternoon salivary cortisol levels in the subject group showed significantly higher median results than those in the control group (p < 0.001), but the two groups were similar with regard to morning salivary cortisol level (p = 0.48). The diurnal variability in salivary cortisol secretion was not present in the subject group and in contrast to controls there was no difference between AM and PM salivary cortisol values in subjects (Fig. 3). AM and PM salivary cortisol levels did not correlate significantly with ISS (AM: r = 0.08, p = 0.58; PM: r = 0.08, p = 0.59) and the diurnal cortisol change did not correlate with ISS (r = 0.05,
Fig. 3. Mean salivary cortisol by group and time of day (6AM, 4PM) showing the mean PM salivary cortisol was significantly increased in patients relative to controls.
p = 0.75). Salivary cortisol did not vary significantly with baseline GCS (p = 0.41), sex (p = 0.29), injury type (p = 0.58), or ethnicity (p = 0.20). The relation between salivary cortisol and age varied significantly with day (p = 0.007), most likely due to the apparent increase in mean salivary cortisol among older subjects (age >49 years) in the afternoon on days 3, 5, and 6. If this interaction with day is ignored, then the relation between salivary cortisol and age was not significant (p = 0.90). When comparing mean AM and PM salivary cortisol by GCS severity category (GCS 68 and GCS >8) the AM salivary cortisol was significantly higher in patients with GCS 68 compared to that in patients with GCS >8 (p = 0.002, Fig. 4A). Mean AM and PM salivary cortisol did not show significant variation with ISS severity category (ISS 8). AM salivary cortisol was significantly increased in patients with GCS 68. (B) Mean AM and PM salivary cortisol by Injury Severity Score (ISS) category (8) brain injured patients. Llompart-Pou et al. studied the acute HPA axis response in patients with traumatic brain injury with and without extracerebral trauma based on blood adrenocorticotropic hormone and cortisol levels between 24 and 48 hours after the trauma [18]. The study did not find any measurable difference in HPA axis responsiveness between the two groups [18]. Measurement of cortisol concentrations in saliva may be a more sensitive approach to reveal differences in HPA axis activity in relation to the severity of head injury. The most important limitation of our study is that morning and evening cortisol values do not necessarily reflect the subtle time and stressor specific functioning of the HPA axis. Therefore, multiple daily saliva samples and cortisol measurements would be preferable in the future and these should be correlated with the
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patient’s vital signs, medications, as well as exposure to interventions and transfers. Conflicts of Interest/Disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. Acknowledgments Sponsored by the Department of the Army, W81XWH-07-10717. The U.S. Army Medical research Acquisition Activity, 820 Chandler Street, Fort Detrick MD 21702-5014 is the awarding and administering acquisition office. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense. The analytical part of the study was supported by APVV-0028-10 and project of Centre of Excellence CEMAN. References [1] Annane D, Sébille V, Charpentier C, et al. Effect of treatment with low doses of hydrocortisone and fludrocortisone on mortality in patients with septic shock. JAMA 2002;288:862–71. [2] Cotton BA, Guillamondegui OD, Fleming SB, et al. Increased risk of adrenal insufficiency following Etomidate exposure in critically injured patients. Arch Surg 2008;143:62–7 [discussion 67]. [3] Sprung CL, Annane D, Keh D, et al. Hydrocortisone therapy for patients with septic shock. N Engl J Med 2008;358:111–24. [4] Marik PE, Pastores SM, Annane D, et al. Recommendations for the diagnosis and management of corticosteroid insufficiency in critically ill adult patients: consensus statements from an international task force by the American College of critical care medicine. Crit Care Med 2008;36:1937–49. [5] Hamrahian AH, Oseni TS, Arafah BM. Measurements of serum free cortisol in critically ill patients. N Engl J Med 2004;350:1629–38. [6] Arafah BM. Hypothalamic pituitary adrenal function during critical illness: limitations of current assessment methods. J Clin Endocrinol Metab 2006;91:3725–45. [7] Loriaux L. Glucocorticoid therapy in the intensive care unit. N Engl J Med 2004;350:1601–2. [8] Jezova D, Hlavacova N. Endocrine factors in stress and psychiatric disorders: focus on anxiety and salivary steroids. Ann N Y Acad Sci 2008;1148:495–503. [9] Kerlik J, Penesova A, Vlcek M, et al. Comparison of salivary cortisol and calculated free plasma cortisol during low-dose ACTH test in healthy subjects. Clin Biochem 2010;43:764–7. [10] Golden SH, Wand GS, Malhotra S, et al. Reliability of hypothalamic–pituitary– adrenal axis assessment methods for use in population-based studies. Eur J Epidemiol 2011;26:511–25. [11] Arafah BM, Nishiyama FJ, Tlaygeh H, et al. Measurement of salivary cortisol concentration in the assessment of adrenal function in critically ill subjects: a surrogate marker of circulating free cortisol. J Clin Endocrinol Metab 2007;92:2965–71. [12] Raff H, Brock S, Findling JW. Cosyntropin-stimulated salivary cortisol in hospitalized patients with hypoproteinemia. Endocrine 2008;34:68–74. [13] Mello RC, Sad EF, Andrade BC, et al. Serum and salivary cortisol in the diagnosis of adrenal insufficiency and as a predictor of the outcome in patients with severe sepsis. Arq Bras Endocrinol Metabol 2011;55:455–9. [14] Delahanty D, Nugent N. Predicting PTSD prospectively based on prior trauma history and immediate biological responses. Ann NY Acad Sci 2006;1071:27–40. [15] Delahanty D, Raimonde A, Spoonster E. Initial posttraumatic urinary cortisol levels predict subsequent PTSD symptoms in motor vehicle accident victims. Biol Psychiatry 2000;48:940–7. [16] Ehring T, Ehlers A, Cleare A, et al. Do acute psychological and psychobiological responses to trauma predict subsequent symptom severities and PTSD and depression? Psychiatry Res 2008;161:67–75. [17] McFarlane AC, Barton CA, Yehuda R, et al. Cortisol response to acute trauma and risk of posttraumatic stress disorder. Psychoneuroendocrinology 2011;36:720–7. [18] Llompart-Pou JA, Raurich JM, Pérez-Bárcena J, et al. Acute Hypothalamic– pituitary–adrenal response in traumatic brain injury with and without extracerebral trauma. Neurocrit Care 2008;9:230–6. [19] Wagner AK, McCullogh EH, Niyonkuru C, et al. Acute hormone levels: characterization and prognosis after severe traumatic brain injury. J Neurotrauma 2011;28:871–88. [20] Cohen J, Venkatesh B, Galligan J, et al. Salivary cortisol concentration in the intensive care population: correlation with plasma cortisol values. Anaesth Intensive Care 2004;32:843–5.
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