Differential influence of open surgery and sepsis on the circulating insulin-like growth factors and their binding proteins as representative metabolic markers

Sepsis as a Pan-Endocrine Illness-Endocrine Disorders in Septic Patients

Sepsis is defined as "life-threatening organ dysfunction caused by a dysregulated host response to infection". One of the elements of dysregulated host response is an endocrine system disorder. Changes in its functioning in the course of sepsis affect almost all hormonal axes. In sepsis, a function disturbance of the hypothalamic-pituitary-adrenal axis has been described, in the range of which the most important seems to be hypercortisolemia in the acute phase. Imbalance in the hypothalamic-pituitary-thyroid axis is also described. The most typical manifestation is a triiodothyronine concentration decrease and reverse triiodothyronine concentration increase. In the somatotropic axis, a change in the secretion pattern of growth hormone and peripheral resistance to this hormone has been described. In the hypothalamic-pituitary-gonadal axis, the reduction in testosterone concentration in men and the stress-induced "hypothalamic amenorrhea" in women have been described. Catecholamine and β-adrenergic stimulation disorders have also been reported. Disorders in the endocrine system are part of the "dysregulated host response to infection". They may also affect other components of this dysregulated response, such as metabolism. Hormonal changes occurring in the course of sepsis require further research, not only in order to explore their potential significance in therapy, but also due to their promising prognostic value.

The cortisol stress response induced by surgery: A systematic review and meta-analysis

OBJECTIVE

Surgery is a stressor that can be categorized by duration and severity and induces a systemic stress response that includes increased adrenal cortisol production. However, the precise impact of surgical stress on the cortisol response remains to be defined.

DESIGN

We performed a systematic review and meta-analysis to assess the cortisol stress response induced by surgery and to stratify this response according to different parameters.

METHODS

We conducted a comprehensive search in several databases from 1990 to 2016. Pairs of reviewers independently selected studies, extracted data and evaluated the risk of bias. Cortisol concentrations were standardized, pooled in meta-analysis and plotted over time.

RESULTS

We included 71 studies reporting peri-operative serum cortisol measurements in 2953 patients. The cortisol response differed substantially between moderately/highly invasive and minimally invasive surgical procedures. Minimally invasive procedures did not show a peri-operative cortisol peak, whereas more invasive surgeries caused a cortisol surge that was more pronounced in older subjects, women and patients undergoing open surgery and general anaesthesia. The duration of the procedure and the use of etomidate for induction of anaesthesia did not affect the cortisol response.

CONCLUSIONS

The peri-operative cortisol stress response is dynamic and influenced by patient-specific, surgical and anaesthetic features. However, the available evidence is derived from highly heterogeneous studies, with only two of 71 studies measuring cortisol by mass spectrometry, which currently prevents a precise and reproducible definition of this response.

Hypothalamic-pituitary hormones during critical illness: a dynamic neuroendocrine response

Independent of the underlying condition, critical illness is characterized by a uniform dysregulation of the hypothalamic-pituitary-peripheral axes. In most axes a clear biphasic pattern can be distinguished. The acute phase of critical illness is characterized by low peripheral effector hormone levels such as T3, IGF-1 and testosterone, despite an actively secreting pituitary. The adrenal axis with high cortisol levels in the presence of low ACTH levels is a noteworthy exception. In the prolonged phase of critical illness, low peripheral effector hormone levels coincide with a uniform suppression of the neuroendocrine axes, predominantly of hypothalamic origin. The severity of the alterations in the different neuroendocrine axes is associated with a high risk of morbidity and mortality, but it remains unknown whether the observed changes are cause or consequence of adverse outcome. Several studies have identified therapeutic potential of hypothalamic releasing factors, but clinical outcome remains to be investigated with sufficiently powered randomized controlled trials.