Beta-endorphin and catecholamine concentrations during chronic and acute stress in intensive care patients

Eur J Med Res. 1996 Sep 20;1(11):528-32.


Background: Only little information is available on the effects of acute and chronic stress on the opioid and adrenergic systems in patients at intensive care units. Animal models showed a stimulation of beta-endorphin and catecholamines.

Methods: In the present study, in 12 patients who were intubated and were receiving artificial respiration because of cardiopulmonary resuscitation or primary respiratory failure, venous plasma concentrations of adrenaline, noradrenaline and beta-endorphin immuno-reactive material (IRM) were determined by a radioimmunoassay. In these patients, regular endobronchial suctioning was necessary. For inducing acute stress patients underwent three different methods of endobronchial suctioning or lavage.

Results: In all patients concentrations of both adrenaline (529 +/- 117 pg/ml) and noradrenaline (2694 +/- 262 pg/ml) were increased above normal resting values. In 5 patients plasma beta-endorphin IRM concentration was below the detection limit, the other patients had beta-endorphin IRM concentrations above normal (26.65 +/- 3.80 pg/ml). Epinephrine (227 +/- 33 vs. 743 +/- 189 pg/ml; p < 0.01) and norepinephrine (1673 +/- 161 vs. 3423 +/- 368 pg/ml; p < 0.001) were significantly lower in the group with undetectable beta-endorphin IRM concentrations than in the group with detectable beta-endorphin IRM whereas heart rate was significantly higher (120/min vs. 99/min; p < 0.0003). beta-endorphin IRM concentrations were correlated negatively to heart rate (-0.55; p < 0.0005) and positively to the noradrenaline concentration (0.56; p < 0.0004). Artificially ventilated patients showed increased levels of beta-endorphin (19.27 +/- 3.16 pg/ml) as compared to the spontaneously breathing patients (13.29 +/- 4.34 pg/ml). Following acute stress due to endobronchial suctioning or lavage, blood pressure (150/70 mmHg vs. 172/81 mmHg; p < 0.01) and heart rate (107/min vs. 119/min; p < 0.005) increased in all patients, the other parameters did not.

Conclusion: It is concluded that beta-endorphin IRM concentration in the plasma is linked to epinephrine and norepinephrine concentrations under intensive care conditions. Endobronchial lavage or suctioning does not influence beta-endorphin IRM levels in plasma.

MeSH terms

  • Acute Disease
  • Adolescent
  • Aged
  • Blood Pressure
  • Bronchoalveolar Lavage*
  • Cardiopulmonary Resuscitation
  • Chronic Disease
  • Consciousness
  • Critical Care
  • Epinephrine / blood*
  • Heart Rate
  • Humans
  • Middle Aged
  • Norepinephrine / blood*
  • Oxygen / blood
  • Pulse
  • Respiration, Artificial*
  • Respiratory Insufficiency / blood
  • Respiratory Insufficiency / physiopathology
  • Sensitivity and Specificity
  • Stress, Physiological / blood*
  • Stress, Physiological / physiopathology
  • beta-Endorphin / blood*


  • beta-Endorphin
  • Oxygen
  • Norepinephrine
  • Epinephrine