Influence of Physostigmine on Patient-Controlled Analgesia (PCA) in Postoperative Intensive Care Patients

Influence of Physostigmine on Patient-Controlled Analgesia (PCA) in Postoperative Intensive Care Patients, Considering Pain Score, Opioid Consumption, Hemodynamics and Cognitive Function

The study is to evaluate the influence of physostigmine in the postoperative period in intensive care patients considering pain quality, opioid consumption, hemodynamics and mobilisation.

Pain management is of major concern in the postoperative period, mostly based on opioids. In numerous experimental and clinical trials cholinergic mechanisms have been demonstrated to play an important antinociceptive role. Physostigmine, a central cholineresterase inhibitor, has been shown to produce analgesia and enhance opiate analgesia after systemic injection. This action is not based on µ-receptor (opioid) activity, but can be mostly explained by stimulation of serotonine (5-HT-3) receptors. The major withdrawal of utilizating physostigmine in postoperative care, is due to its short duration of action.

In the present study, we examined the effect of a continuous intavenous physostigmine application during a patient-controlled analgesia with piritramide for 48 hours compared to a placebo infusion with NaCl.

Major concern was set for consumption of analgesics, VAS-pain scale, hemodynamics, mobilisation and side effects.

Inclusion Criteria:

• Age 18-80 years
• Indication for postoperative pain therapy and admission to ICU
• ASA I-III
• Weight 50-125 kg
• Patients that are willing to participate in the present study

Exclusion Criteria:

• Peridural anesthesia for pain management
• Severe left ventricular function (EF <30%)
• Severe/exacerbated COPD; Asthma
• ASA IV-V
• Chronic renal insufficiency(Creatinine > 1,5 mg/dl)
• Ulcera ventriculi
• Known allergy to any of the study agents
• Hb preoperative <9,5 g/dl
• Alcohol,drug and/or tablet abuse (Opioids, NSAR)
• Emergency operation
• Pregnancy
• Women of childbearing age and without a negative pregnancy test
• Severe liver disease (GOT oder GPT > 45 U/L)
• Severe neurologica derangements (e.g. M. Parkinson, Multiple Sklerosis)
• History of apoplexia <6 Monate or residua
• Perioperative myocardial infarction
• Patients that are not able to agree to the present study
• Patients that refuse to participate in the present study
• Patients that are part of any other study