Nitrous Oxide (N2O)

MAC 100%, blood/gas solubility ratio 0.47
- An inorganic gas., low solubility in blood, but greater solubility than N2
- Inflammable, but does support combustion.
- Excreted primarily unchanged through the lungs.
- It provides amnesia and analgesia when administered alone.
- Does not produce muscular relaxation.
- Less depressant to both the cardiovascular system and respiratory system than most of the other inhalational anesthetics.
- Lack of potency and tendency to produce anoxia are its primary limitations.
- The major benefit of nitrous oxide is its ability to reduce the amount of the secondary anesthetic agent that is necessary to reach a specified level of anesthesia.

Patient positioning

The most common medical emergency encountered in the dental office setting is syncope. So patients in the supine or semi-supine position to improve venous return and cerebral blood flow provided that the position is tolerated by the patient and is appropriate for their medical condition.

Stages of anesthesia

Stage I

Analgesia

Still conscious but drowsy

Stage II

Excitement stage

Loss of consciousness, however, irregular ventilation may be present which affects absorption of inhalation agents.

Reflexes may be exaggerated.

This is a very dangerous stage

Stage III

Surgical anesthesia

Loss of spontaneous movement

Regular, shallow respiration

Relaxation of muscles

Stage IV

Medullary paralysis

Death

Doxycycline

Commonly prescribed for infections and to treat acne. treat urinary tract infections, gum disease, and other bacterial infections such as gonorrhea and chlamydia., as a prophylactic treatment for infection by Bacillus anthracis (anthrax). It is also effective against Yersinia pestis and malaria.

Kinins
Peptide that are mediated in the inflammation.
Action of kinin:
On CVS: vasodilatation in the kidneys, heart, intestine, skin, and liver. It is 10 times active than histamine as vasodilator.

On exocrine and endocrine glands: kinin modulate the tone of pancreas and salivery glands and help regulate GIT motility, also affect the transport of water and electrolytes, glucose and amino acids through epithelial cell transport.

TRIMETHOPRIM

It is a diaminopyrimidine. It inhibits bacterial dihydrofolate reductase( DHFRase).

In combination with sulphamethoxzole it is called Co-trimoxazole.

Spectrum of action

 S. Typhi. Serratia. Klebsiela and many sulphonamide resistant strains of Staph.aureus. Strep pyogens

Adverse effects

Megaloblastic anemia. i.e.. due to folate defeciency.

Contraindicated in pregnancy.

Diuretics if given with co-trimoxazole cause thrombocytopenia.

Uses

I. UTI. 2. RTI. 3. Typhoid. 5. Septicemias. 5. Whooping cough