Anaesthesia solutions

Most studies were performed with hyperosmolar solutions. Hypertonic disruption is under clinical evaluation for enhanced delivery of small molecular weight cytostatic agents to brain tumours. Technically, the procedure is performed as a high-flow short-term infusion of 25% mannitol or arabinose under general anaesthesia. The underlying mechanism is a sequelae of endothehal cell shrinkage, disruption of tight junctions and vasodilatation by osmotic shift [72]. 

Thiopentone sodium is usually given as 92.5 percent solution, initially 100 to 150 mg over 10-15 seconds and repeated if necessary depending upon the patient s response after 20-30 seconds. On repeated administration the extracerebral sites are gradually filled up and lower doses produces anaesthesia which lasts longer. 

Thiopentone is administered as a 2.5% solution, the usual intravenous induction dose being 3-5 mg kg-1 in adults and 5-6 mg kg-1 in children. The dose necessary to induce anaesthesia is reduced by premedication, during early pregnancy and in critically ill patients. Patients over 70 years of age require a 30-40% lower dose because of a decrease in the volume of distribution, lower plasma proteins, and a slower redistribution of the drug from vessel-rich tissues. However, the above doses are merely guidelines, and the calculated dose should be administered over 10-20 seconds and the drug titrated to clinical effect, i.e. loss of eyelash reflex. 

Intra-arterial injection of thiopentone is a serious complication as crystals of the thiobarbiturate can form in the arterioles and capillaries, causing intense pain, vasoconstriction, thrombosis, and even tissue necrosis. Accidental intra-arterial injections should be treated promptly with intra-arterial administration of a vasodilator (papaverine 20 mg) and lignocaine (lidocaine) Note leave the needle/cannula in the artery), as well as a regional anaesthesia-induced sympathectomy (stellate ganglion block, brachial plexus block) and anticoagulation with intravenous heparin. The risk of ischaemic damage is much higher with a 5% solution and the use of this concentration is not recommended. 

Based on clinical trials, Geiger (2005) postulated that a 5% solution of essential oil of ginger is an effective post-operative nausea and vomiting (PONV) prevention when administered pre-operatively, naso-cutaneously, concurrently with conventional therapies, to general anaesthesia patients at high risk of PONV. 

Clove oil is used as a safe anaesthetic for aquatic research. Tricaine or MS-222, the only anaesthetic registered in North America, is a very effective anaesthetic for several fish species but its application in the field is limited because the US Food and Drug Administration guidelines demand a 21-day withdrawal period after exposure to MS-222 before the fish enters the food chain. In this context, clove oil is found to be an alternative to MS-222 for use as a fish anaesthetic. Exposure of channel catfish (Ictalurus punctatus) to clove oil at a concentration of 100mg/l induced anaesthesia within 1 min. The fish recovered from a 10 min period of anaesthesia within 4 min after removal from the anaesthetic solution. 

Dose. A solution containing alphaxalone 9 mg and alphadolone acetate 3 mg/ml has been administered intravenously doses of 0.05 to 0.075 ml/kg and 10 to 20ml/hour have been given to induce and maintain anaesthesia, respectively. 

Dose. 5 to 20 mg of amethocaine hydrochloride (0.5% solution) is injected for spinal anaesthesia 0.5 to 2% solutions have been used for surface anaesthesia. 

Use. A 2% solution of butacaine sulphate has been used for surface anaesthesia. 

Gangerosa, L. P. Defining a practical solution for iontophoretic local anaesthesia of skin. Meth. Find. Exp. Clin. Pharmacol. 5 83, 1981. 

Surface anaesthesia, as solution, jelly, cream or lozenge. 

Subarachnoid (intrathecal) block (spinal anaesthesia). By using a solution of appropriate specific gravity and tilting the patient the drug can be kept at an appropriate level. Sympathetic nerve blockade causes hypotension. Headache due to CSF leakage is virtually eliminated by using very narrow atraumatic penal point needles. 

Adams HA, Biscoping J, Kafurke H, Muller H, Hoffmann B, Boerner U, Hempelmann G. Influence of dextran on the absorption of adrenahne-containing hgno-caine solutions a protective mechanism in local anaesthesia. Br J Anaesth 1988 60(6) 645-50. 

It is decomposed bywarm HaO, by alkalies, by HsSO, HaS, and the alkaline sulflds, and is liable to spontaneous decomposition especially in the presence of HaO. Its vapor produces anaesthesia, and it exists in alcoholic solution in Spiritus aetheris nitrosi (XJ. S., Br.), which also contains aldehyde, which latter substance by its oxidation frequently renders the spirit acid and unfit for use. (See Nitro-parafiins.)... 

It is a basal anaesthetic agent of choice which is administered through rectum in the form of its solution. The main advantage of such an anaesthesia being its pleasant induction amalgamated with lack of irritating vapours. 

It is one of the least toxic and most commonly used local anaesthetics. The salient features for its wide popularity may be attributed due to its lack of local irritation, minimal systemic toxicity, longer duration of action, and low cost. It can be effectively used for causing anaesthesia by infiltration, nerve block, epidural block or spinal anaesthesia. In usual practice it is used in a solution containing adrenaline (1 50,000) which exerts and modifies the local anaesthetic activity through retarded absorption, and the duration of action is considerably prolonged. 

Dose For infiltration anaesthesia 1% for nerve block anaesthesia 1 and 2% solution andfor topical application to skin and mucous membranes 1 to 5%. 

It is a local anaesthetic of the amide type which is employed for surface, infiltration and nerve block anaesthesia. Its duration of action is in between the shorter-acting lidocaine and longer-acting mepivacaine. It possesses less vaso-dilator activity than lidocaine and hence may be used without adrenaline. Therefore, solutions of prilocaine hydrochloride are specifically beneficial for such patients who cannot tolerate vasopressor agents patients having cardiovascular disorders, diabetes, hypertension and thyrotoxicosis. 

It is one of the oldest synthetic local anaesthetics. It is chiefly employed as a 1% solution for effeeting local anaesthesia of the eye. 

Its solution finds usage as a topical local anaesthesia in dentistry. It has also been employed in several ear and nose drops for the relief of pain along with other drugs. 

Young K. H3 otension from die interaction of ACE inhibitors widi stable plasma protein solution. Anaesthesia (1993) 48, 356. 

An 89-year-old man with congestive heart failure taking oral eimetidine had two seizures lOto 15 minutes after accidental ora/ingestion of lidoeaine solution for oesophageal anaesthesia. He had a high serum lidoeaine level of 7.8 micrograms/mL. ... 

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