Anesthesiology and Intensive Care

Coma :   Closed eyes, sleeplike state  with no response to external stimuli (pain). People have no corneal or gag reflex, and they may have no pupillary response to light. Stupor : Responsive only to vigorous or painful stimuli by grimacing or drawing away from painful stimuli. Obtunded : A person has a decreased interest in their surroundings, slowed responses, and sleepiness.

    Increased hydrostatic pressure in the pulmonary capillaries results in increased transvascular fluid filtration and is most often caused by volume overload or impaired left ventricular function resulting in elevated pulmonary vascular pressures.

Cardiorespiratory arrest or impending arrest.

    In left bundle branch block there is a delay or blockage of conduction in the main left bundle  branch. This affects the normal depolarisation in the ventricles.     In left bundle branch block, the impulse begins in the SA node and depolarises the atria, then  travels through the AV node to the left and right bundle branches. On finding the left bundle branch  blocked, the impulse travels down the right bundle branch.

Hyperventilation – in the short term, hyperventilation to a PaCO2 of 25 mmHg can reduce cerebral blood flow, reducing ICP. This must be balanced, however, against the increased intrathoracic pressure required to hyperventilate the patient’s lungs, which can reduce venous return causing hypotension. Meanwhile vasoconstriction in the areas under carbon dioxide control might decrease compensatory blood flow. Mannitol – bolus administration of this 6-carbon sugar has three effects:

Face Mask LMA ETT Procedure duration Short Short–Medium Any Protection against aspiration No No Yes Peak inspiratory pressure* < 20 cmH2O < 20 cmH2O Any Stimulation by device Low Medium High LMA Laryngeal Mask Airway ETT Endotracheal Tube * Pressures above 20 cmH2O may distend the stomach

    SHOCK is a state of inadequate tissue perfusion, leading to tissue hypoxia and organ  dysfunction.      Shock is classified according to one of four mechanisms:

Drugs known to cause congenital malformations:

    Increased morbidity results from hypoxemia, hypoventilation resulting in acute hypercarbia, pulmonary infection, prolonged intubation, and mechanical ventilation. Patients presenting for lobectomy or pneumonectomy as well as those with pulmonary comorbidity must have pulmonary function and arterial blood gas values. A forced expiratory volume in 1 second (FEV1) less than 800 ml in a 70-kg person is probably incompatible with life and is an absolute contraindication to lung resection because of the high incidence for extended mechanical ventilation.

The anesthetic level required depends on the surgical procedure.  Dermatomal level requirements for a selection of  operations:

         Endotracheal tube sizing:

         ACC/AHA cardiac evaluation and care algorithm for non-cardiac surgery based on active clinical conditions, known cardiovascular disease, or cardiac risk factors for patients 50 years of age or greater. A stepwise approach to the risk assessment of patients with pre-existing cardiac disease, scheduled for surgery. Subsequent care may include cancellation or delay of surgery, coronary revascularization followed by non-cardiac surgery, or intensified care.  click the picture to enlarge:

STATEMENT ON SMOKING CESSATION  Committee of Origin: Task Force on Smoking Cessation (Approved by the ASA House of Delegates on October 22, 2008, and reaffirmed on October 16, 2013) 

    Postoperative nausea and vomiting ( PONV   ) is the result of multiple  of perioperative factors such as fasting, autonomic imbalance,  pain, and anesthetic effects on chemotactic centers.     The emetic centers are located in the lateral reticular formation of the medulla.

    The severity of a burn injury is based on the amount of surface area covered in deep  partial-thickness, full-thickness, and subdermal burns. The rule of nines method allows  reasonable estimation. Because of the difference in body habitus (particularly  head and neck), the rule of nines must be altered in children.