Concentration effect

In the study of inhaled anesthetics, the concentration effect is the increase in the rate that the Fa(alveolar concentration)/Fi(inspired concentration) ratio rises as the alveolar concentration of that gas is increased. In simple terms, the higher the concentration of gas administered, the faster the alveolar concentration of that gas approaches the inspired concentration. In modern practice is only relevant for nitrous oxide since other inhaled anesthetics are delivered at much lower concentrations due to their higher potency.

References

Korman B, Mapleson WW (1997). "Concentration and second gas effects: can the accepted explanation be improved?". Br J Anaesth. 78 (5): 618–25. PMID 9175984. {{cite journal}}: Unknown parameter |month= ignored (help)
Taheri S, Eger EI 2nd (1999). "A Demonstration of the Concentration and Second Gas Effects in Humans Anesthetized with Nitrous Oxide and Desflurane". Anesthesia and Analgesia. 89 (3): 774. PMID 10475324. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: numeric names: authors list (link)

v t e Anesthesia and anesthesiology
Types	General Sedation Procedural sedation and analgesia Twilight anesthesia Local Continuous wound infiltration Topical Neuraxial blockade Combined spinal and epidural anaesthesia Epidural anesthesia Spinal anaesthesia Nerve block Brachial plexus block Fascia iliaca block Femoral nerve block Inferior alveolar nerve block Intercostal nerve block Interpleural block Intravenous regional anesthesia Occipital nerve block Paracervical block Pudendal nerve block Retrobulbar block Sciatic nerve block Transverse abdominis plane block Total intravenous anaesthesia
Pharmacologic agents	Anticholinergics Antiemetics Butyrophenones Benzodiazepines General anesthetics Inhalational anesthetics Local anesthetics Neuromuscular-blocking drugs Opioids Sedatives
Techniques	Airway management Anesthesia provision in the US Bronchoscopy Dogliotti's principle Intravenous therapy Laryngoscopy Tracheal intubation Rapid sequence induction
Scientific principles	Blood–gas partition coefficient Concentration effect Fink effect Minimum alveolar concentration Second gas effect
Measurements	ASA physical status classification system Baricity Bispectral index Body mass index Capnography Entropy monitoring Fick principle Goldman index Guedel's classification Intraoperative neurophysiological monitoring Mallampati score Neuromuscular monitoring Pain scale Thyromental distance
Instruments	Anaesthetic machine Anesthetic vaporizer Arterial catheter Bronchial blocker Double-lumen endobronchial tube Gas cylinder Laryngeal mask airway Laryngeal tube Magill forceps Relative analgesia machine Tracheal tube
Complications	Allergic reactions Anesthesia awareness Drug-induced amnesia Effects of early-life exposures to anesthesia on the brain Emergence delirium Local anesthetic toxicity Malignant hyperthermia Perioperative mortality Postanesthetic shivering Postoperative nausea and vomiting Postoperative residual curarization
Subspecialties	Cardiothoracic Critical emergency medicine Geriatric Intensive care medicine Obstetric Oral sedation dentistry Pain medicine
Professions	Anesthesiologist Anesthesiologist assistant Nurse anesthetist Operating department practitioners Certified anesthesia technician Certified anesthesia technologist Anaesthetic technician Physicians' assistant (anaesthesia)
History	ACE mixture Helsinki Declaration for Patient Safety in Anaesthesiology History of general anesthesia History of neuraxial anesthesia History of tracheal intubation
Organizations	American Association of Nurse Anesthetists American Society of Anesthesia Technologists & Technicians American Society of Anesthesiologists Anaesthesia Trauma and Critical Care Association of Anaesthetists of Great Britain and Ireland Royal College of Anaesthetists Association of Veterinary Anaesthetists Australian and New Zealand College of Anaesthetists Australian Society of Anaesthetists International Anesthesia Research Society European Society of Anaesthesiology and Intensive Care
Category Outline

See also

References