Anesthesia, general

M. J. Halsey, R. A. Miller, and J. A. Sutton, Molecular Mechanisms in General Anesthesia, ChurchiU Livingston, Edinburgh, Scodand, 1974. 

The membrane enzyme luciferase, responsible for light emission in fireflies, is sensitive to anesthetics (20,21), and the concentrations of inhalational agents which inhibit luciferase are the same as those which cause general anesthesia. Studies of various classes of inhalational agents and luciferase demonstrated that above a certain chain length in a homologous series, a point is reached where higher members are not anesthetic. The same cut-off effect in efficacy is observed in anesthesia (22). This effect is not explainable by Hpid theory. 

Clinical evaluation is underway to test transvenous electrodes. Transvenous leads permit pacemakers to be implanted under local anesthesia while the patient is awake, greatly reducing recovery time and risk. As of 1996, the generation of implantable defibrillators requires a thoracotomy, a surgical opening of the chest, in order to attach electrodes to the outside of the heart. Transvenous electrodes would allow cardiologists to perform pacemaker procedures without a hospital or the use of general anesthesia. 

Water-soluble contrast media (CM) are preferred because of effective mixing with CSF, plus the radiopaque is absorbed and effectively excreted in the urine, and does not have to be physically removed from the subarachnoid space after the procedure. Sodium methiodal, the first water-soluble agent used for myelography, produced neurotoxicity problems when exposed to the cells of the spinal cord and brain, thus limiting utility to the lumbar region and requiring the appHcation of spinal or general anesthesia. 

It must be remembered that all anesthetics and tranquilizers are used by the practitioner following a risk—benefit evaluation. General anesthesia, even being adininistered by an experienced practitioner, can result in death through cardiac or respiratory depression. The veterinarian is acutely aware of these risks and chooses the dmg and method of adininistration considering the patient s health status, the nature of and need for the procedure, and the likelihood of success. 

Although the use of barbiturates and miscellaneous sedatives and hypnotics for sedation has largely been replaced by the antianxiety drugs (see Chap. 30), they occasionally may be used to provide sedation before certain types of procedures such as cardiac catheterization or the administration of a local or general anesthesia Sedative doses usually given during daytime hours, may be used to treat anxiety and apprehension. Fhtients with chronic disease may require sedation, not only to reduce anxiety, but also as an adjunct in the treatment of their disease... 

List several drugs used in local and general anesthesia. 

List and briefly describe the four stages of general anesthesia. 

The administration of general anesthesia requires the use of one or more drug . The choice of anestiietic drug depends on many factors, including... 

The anesthesiologist selects the anesthetic drug that will produce safe anesthesia, analgesia (absence of pain), and in some surgeries, effective skeletal muscle relaxation. General anesthesia is most commonly achieved when the anesthetic vapors are inhaled or administered intravenously (IV). Volatile liquid anesthetics produce anesthesia when their vapors are inhaled. Volatile liquids are liquids that evaporate on exposure to air. Examples of volatile liquids include halothane, desflurane, and enflurane. Gas anesthetics are combined with oxygen and administered by inhalation. Examples of gas anesthetics are nitrous oxide and cyclopropane. 

Sevoflurane (Ultane) is an inhalational analgesic. It is used for induction and maintenance of general anesthesia in adult and pediatric patients for inpatient and outpatient surgical procedures. 

The various skeletal muscle relaxants that may be used during general anesthesia are listed in Table 35-3. These drugp are administered to produce relaxation of the skeletal muscles during certain types of surgeries, such as those involving the chest or abdomen. They may also be used to facilitate the insertion of an endotracheal... 

TABLE 35-3 Examples of Muscle Relaxants Used During General Anesthesia... 

Discuss the most important responsibilities of the nurse in the recovery room after a patient has undergone general anesthesia. 

Which of the following drug s is the most commonly used gas for general anesthesia ... 

One use of skeletal muscle relaxants as part of general anesthesia is to. ... 

Kaplan and Kelloner estimated that between 1972 and 1982, the number of deliveries with general anesthesia in the U.S., Canada, and Great Britain was 29,31,300. Only four cases of MH were reported in obstetric cases during this time. These statistics support Crawford s view that pregnancy may have a protective effect against MH (Crawford, 1972). 

Ultrarapid detoxification employs general anesthesia and opioid antagonists to accomplish withdrawal more quickly (Alvarez and Carmen del Rio 1999 Bell et al. 1999 Brewer et al. 1998 Brewer and Maksoud 1997 Gerra et al. 2000 Kleber 1998 Rabinowitz et al. 1998 SanandArranz 1999 Shreeram et al. 2001 Stephenson 1997 Strang et al. 1997). Its efficacy and safety are being studied. 

Barbiturates produce CNS depression, which ranges from sedation to general anesthesia. Action is through suppression of the mesencephalic reticular activating system. Barbiturates enhance GABA-induced inhibition the site of inhibition may be presynaptic in the spinal cord or postsynaptic in the cortical... 

Miller KW The nature of the site of general anesthesia. Int RevNeurobiol 27 1—61, 1985... 

Drugs (radiocontrast media, drugs used in general anesthesia, codeine morphine, dextromethorphan, aspirin, and other analgesics)... 

EC-IC arterial bypass involves the use of general anesthesia, open craniotomy, and end-to-side anastomosis of the superficial temporal artery to a branch of the middle cerebral artery (MCA) (Fig. 6.1). Currently, this technique is being used primarily in the setting of intracranial aneurysm therapy, moyamoya disease, and... 

Venous stasis Major medical illness (e.g., congestive heart failure) Major surgery (e.g., general anesthesia for greater than 30 minutes) Paralysis (e.g., due to stroke or spinal cord injury) Polycythemia vera Obesity Varicose veins... 

The first step in preventing PONV is reducing baseline risk factors when appropriate.6 Regional anesthesia rather than general anesthesia should be used. Opioids should be replaced... 

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