[Shivering and rigor during the awakening period]

Area of Science:

• Anesthesiology
• Neurosurgery
• Pharmacology

Background:

• Postoperative shivering and rigor are common complications after microsurgical procedures under anesthesia.
• Balanced anesthesia, particularly neuroleptanalgesia (NLA)-based anesthesia, is frequently employed in microsurgery.
• Thermal regulation during anesthesia significantly influences the incidence of postoperative muscular hyperactivity.

Purpose of the Study:

• To investigate the incidence and characteristics of muscular hyperactivity during the awakening period after microsurgery.
• To evaluate the efficacy of pharmacological (ketamine, trilene, tramal, nubain) and non-pharmacological (warming measures) interventions in preventing shivering and rigor.
• To explore the correlation between the intensity of muscular hyperactivity and the recovery of pain sensitivity and consciousness.

Main Methods:

• Observational study involving 116 patients undergoing microsurgery.
• Administration of ketamine and trilene during tissue revascularization under controlled and uncontrolled thermal conditions.
• Assessment of shivering and rigor intensity.
• Correlation analysis between muscular hyperactivity and pain sensitivity/consciousness recovery.
• Evaluation of tramal and ketamine efficacy, and nubain's unsuitability.

Main Results:

• Muscular hyperactivity (shivering, rigor) was observed during awakening in patients who underwent microsurgery.
• Ketamine and trilene, along with warming measures, demonstrated efficacy in preventing shivering and rigor.
• A strong negative correlation was found between muscular hyperactivity and pain sensitivity recovery (r from -0.73 to -0.98).
• A strong positive correlation was observed between muscular hyperactivity and the level of consciousness recovery (r from 0.69 to 0.92).
• Tramal (96%) and ketamine (80%) were effective treatments, whereas Nubain was ineffective.

Conclusions:

• Ketamine and trilene, combined with warming strategies, are effective in managing postoperative shivering and rigor after microsurgery.
• The intensity of postoperative muscular hyperactivity is closely linked to the recovery of pain sensitivity and consciousness.
• Tramal and ketamine represent viable therapeutic options for treating postoperative shivering and rigor, with Nubain being unsuitable.