Anesthesia anesthetic safety

In animal studies, the 4-hour LCso in rats was 278,000ppm and the 2-hour LCso in mice was 287,000. Early studies reported similar values with 270,000ppm for 2 hours, causing death in 40% of exposed mice, and 310,000ppm for 2 hours, causing 60% mortality. In dogs, lethality was observed at concentrations of 200,000-2 50,000 ppm anesthesia and relaxation preceded death. In animal studies, there was only a small margin of safety between anesthetic and lethal concentrations. 

PCP was first developed in 1926 as an anesthetic to be used in surgery. Early on, the drug showed promise because it appeared to produces anesthesia without depressing breathing or heart rates. Still, lingering questions about safety and effectiveness meant it was largely ignored until 1957. 

DOT CLASSIFICATION Forbidden SAFETY PROFILE A human poison by ingestion and possibly other routes. Poison experimentally by ingestion, intraperitoneal, intravenous, subcutaneous, and parenteral routes. Human central nervous system effects by ingestion and possibly other routes general anesthesia, hallucinations or distorted perceptions, and convulsions. An eye irritant. A widely abused, controlled substance. Abuse leads to habituation or addiction. In medicine, it is used as a local narcotic anesthetic applied topically to mucous membranes. The free base is soluble... 

Injections into the subcutaneous or intradermal sites do not require that the animals are anesthetized however, intradermal injections are significantly easier when the animals are unconscious or sedated. Metastatic potential does not seem to be affected by anesthetics at this step. Methoxyllurane (Metofane , Pitman-Moore) inhalation anesthetic is relatively inexpensive and effective for this purpose. A homemade anesthesia jar will suffice. Place a small volume of Metofane under a wire screen suspended above the floor of a container with a lid. Mice and rats will be unconscious within 3-5 min and the effects will last less than 5 min. It is crucial that the animals never come into contact with the fluid. Transdermal absorption can be lethal. Also, anyone using this inhalant should also be cognisant of the content within the Material Safety Data Sheets (MSDS) and the chances of pathologies if overexposed. Hint construct the anesthesia jar with a wire mesh that allows feces to drop as this maintains clean conditions. This provides for easier and more complete cleaning of the jar. 

Nephrotoxicity has been found with methoxyflurane when serum fluoride ion concentrations exceeded 50 pmol/l (SEDA-20,106). Although this safety threshold has been applied to other volatile anesthetics as well, renal toxicity has not been reported for the other three anesthetics, even though the threshold can be exceeded during prolonged anesthesia. 

Propanidid was used as an intravenous anesthetic for rapid induction and for maintenance of general anesthesia of short duration. However, it was withdrawn because of safety considerations regarding the solvent used, polyethoxylated castor oil (Cremophor EL) (SED-11, 211) (1). 

Convulsions have occurred after inadvertent intravenous injection of ropivacaine during regional anesthesia (4,5). CNS adverse effects from ropivacaine occur before or without severe cardiovascular toxicity, as there have been several similar reports of CNS toxicity, but not yet one with severe or fatal cardiotoxicity. This reinforces the claim of increased safety from cardiovascular toxicity with this enantiomeric local anesthetic compared with racemic bupivacaine. 

Intravenous regional ane.sthesia is used to anesthetize a large region, such us a limb. The anesthetic is injected into a suitable vein in a limb that has had its blood flow restricted by a tourniquet. The efficiency and safety of the technique depends on preventing arterial flow for the duration of the anesthesia. Lignocaine is frequently used to produce intravenous regional anesthesia, but bupivacaine is not approved for this purpose because of its long duration of action. 

Hypersensitivity to amide-type local anesthetics, Adams-Stoke syndrome, supraventricular arrhythmias, Wolf-Parkinson-White syndrome. Spinal anesthesia contraindicated in septicemia. Caution Dosage should be reduced for elderly, debilitated, acutely ill safety in children has not been established. Severe renal/hepatic disease, hypovolemia, CHF, shock, heart block, marked hypoxia, severe respiratory depression, bradycardia, incomplete heart block. Anesthetic solutions containing epinephrine should be used with caution in peripheral or hypertensive vascular disease and during or following potent general anesthesia. Sulfite sensitivity or asthma for some local and topical anesthetic preparations. Tartrazine or aspirin sensitivity with some topical preparations. Anxiety, insomnia, apprehension, blurred vision, loss of hearing acuity, and nausea CNS depression, convulsion and respiratory depression... 

Modem inhalation anesthetics are fluorinated to reduce the flammabihty. They were initially considered to be biochemically inert substances. However, with time came the recognition that not only are inhaled anesthetics metabolized in vivo [27] but also that their metabolites are responsible for both acute and chronic toxicities [28, 29]. Information gained from research over the past 30 years has led to changes in anesthesia practice, discontinuing the use of some anesthetics, for example methoxyflurane, due to its nephrotoxicity and more selective use of others, i.e. halothane, due to its rare liver toxicity. It has also provided the impetus for the development of new agents, isoflurane and desflurane, with properties that lower their toxic potential. The result has been improved safety but room remains for further improvement as our insight into toxicological mechanisms expands. 

There are several clinical applications for neuromuscular blockade. The most important by far is the induction of muscle relaxation during anesthesia for effective surgery. Without such drugs deeper anesthesia, requiring more anesthetic, would be needed to achieve the same degree of muscle relaxation tracheal intubation would also be impossible because of strong reflex response to tube insertion. It is the decreased need for anesthetics, however, that represents increased surgical safety. 

Sodium pentothal (also called thiopental sodium) is commonly used as an intravenous anesthetic. The onset of anesthesia and the loss of consciousness occur within seconds of its administration. Care must be taken when administering sodium pentothal because the dose for effective anesthesia is 75% of the lethal dose. Because of its toxicity, it cannot he used as the sole anesthetic. It is generally used to induce anesthesia before an inhalation anesthetic is administered. Propofol is an anesthetic that has all the properties of the perfect anesthetic It can he used as the sole anesthetic by intravenous drip, it has a rapid and pleasant induction period and a wide margin of safety, and recovery from the drug is rapid and pleasant. 

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