Anesthesiology and Intensive Care

Anatomical Sites of Action General anaesthetic agents affect both brain and spinal cord to account for physiological responses to nociception, loss of consciousness and inhibition of explicit memory. Auditory and sensory evoked potential data implicate the thalamus as the most likely primary target, but secondary sites such as the limbic system (associated with memory) and certain cortical areas are also

Emergency Treatment for An Acute MH Event READ ALSO:  Malignant hyperthermia: Causes and Clinical Manifestations The following four things should be done as soon as possible: Notify surgeon to halt the procedure ASAP( as  soon  as possible ): Discontinue volatile agents and succinylcholine.

Malignant hyperthermia (MH) is a rare life-threatening genetic hypermetabolic muscle disease, signs and symptoms of which most commonly triggered with exposure to inhaled general anesthetics or succinylcholine.  Epidemiology: 1:15,000 in pediatric patients and 1:40,000 adult patients.

    Sevoflurane used as an inhalational (volatile) anaesthetic for induction and maintenance of general anesthesia. Sevoflurane acts as a positive allosteric modulator of the GABAA receptor and an NMDA receptor antagonist .

 MAC: prevents movement in response to surgical stimulationin 50% of patients  1.3 MAC: prevents movement in response to surgical stimulation in 95% of patients 0.3–0.4 MAC: associated with awakening from anesthesia  1.5–1.7 MAC: the concentration required to block autonomic reflexes to surgical stimulation

Oxygen delivery and consumption calculations should be utilised to evaluate and optimize gas exchange: Oxygen Delivery: DO2 = 10 x CI x CaO 2 Oxygen Consumption: VO 2  = 10 x CI x (CaO2 — CvO 2 ) Where: CaO 2  (arterial oxygen content) = (Hb x 1.36 x SaO 2 ) + (0.0031 x PaO 2 ),  and  CvO 2  (mixed venous oxygen content) = (Hb x 1.36 x SvO 2 ) + (0.0031 x PvO 2 ) CI = cardiac index HB = hemoglobin SaO 2  = arterial oxygen saturation PaO 2  = partial pressure of oxygen in arterial blood SvO 2  = venous oxygen saturation PvO 2  = partial pressure of oxygen in venous blood