تخدير اولى

• Anxiolytic drugs


  These drugs used to decrease the anxiety of the patients and make him sedative and calm with amnesia (unable to remember)
• Anxiolytic drugs


  • Act predominantly on GABA receptors
  • Minimum cardiac and respiratory depression
  • Do not produce nausea and vomiting
  • Lack the analgesic effect
  • Cross the placenta and may cause neonatal depression
• Main anxiolytic drugs


  • Diazepam
  • Midazolam
  • Lorazepam
  • Alprazolam
• Benzodiazepines


  Exhibit anxiolytic, sedative, amnesic and anticonvulsant properties
• Diazepam


  Dominant sedative and anxiolytic for oral premedication, rapidly absorbed when given by mouth, exerts an anxiolytic action similar to that of morphine
• Diazepam


  Causes anterograde amnesia and is devoid of emetic side effects, but has variable and unpredictable anxiolytic and sedative action and a long elimination half-life
• Midazolam


  Water-soluble benzodiazepine, more potent, faster onset and shorter duration of action than diazepam, with negligible soporific effects of metabolites
• Midazolam


  • Water solubility minimizes pain at the injection site
  • Lipid solubility ensures rapid distribution in tissues
• Midazolam


  Suitable agent for producing conscious sedation in short endoscopic procedures, preoperative sedation and for induction of general anesthesia
• Midazolam provides pre-operative sedative effect superior to that of diazepam, with good local tolerability and hemodynamic stability
• Analgesic drugs


  Given pre-operatively to reduce the required dose of anesthetic agent and improve patient comfort in the immediate postoperative period
• Analgesic drugs options


  • Opioids
  • Paracetamol
  • Non-steroidal anti-inflammatory drugs (NSAIDs)
• NSAIDs are commonly used, particularly for postoperative pain relief
• Midazolam


  Provides pre-operative sedative effect superior to diazepam, good local tolerability, and good hemodynamic stability
• Midazolam has been found to provide pre-operative sedative effect superior to diazepam
• Midazolam


  • Provides good local tolerability
  • Provides good hemodynamic stability
• Analgesic drugs


  Given pre-operatively, reduce the required dose of anesthetic agent and improve patient comfort in the immediate postoperative period
• Analgesic drugs options


  • Opioids
  • Paracetamol
  • Non-steroidal anti-inflammatory drugs (NSAIDs)
• NSAIDs


  Commonly used, particularly in day surgery, unless there are contra-indications
• Opioids


  • Usually the agents of choice in the presence of acute severe pain
  • In the absence of pain, some people may experience intense dysphoria
  • Cause variable sedation and cardiorespiratory depression
  • Can cause nausea and vomiting which may outweigh any beneficial effects
  • May precipitate bronchospasm or anaphylaxis
• Clonidine given as a premedication has been shown to reduce postoperative pain in children
• Relevant pre-operative pain relief naturally depends on the nature of the procedure as well as factors relating to the individual patient
• Classifications of opioids


  • Natural Opium Alkaloids: Morphine and Codeine
  • Semi-synthetic: Diacetylmorphine (Heroin) and Pholcodeine
  • Synthetic Opioids: Pethidine (Mepiridine) and its congeners Diphenoxylate and Loperamide Fentanyl and its congeners fentanyl, and remifentanil
• Opioids


  • Can be given parenterally
  • Produce sedation
  • Control elevated blood pressure during endotracheal intubation
• Pethidine versus morphine


  • 1/10th as potent as Morphine, but Efficacy is similar
  • Produces as much sedation, euphoria and respiratory depression in equianalgesic dose and similar abuse potential
  • Less spasmodic action in smooth muscles
  • Less miosis, constipation and urinary retention
  • Rapid but short duration of action (2-3 Hrs)
  • Vagolytic effect
  • Tachycardia – Devoid of antitussive action
  • Less histamine releases
  • Safer in asthmatics
• Pharmacokinetics


  • Well absorbed orally, bioavailability 50%
  • Effects appear in 10-15 min. after oral absorption
  • On parenteral administration action lasts for 2-3 Hrs
  • Metabolized in liver, Excreted in urine
• Fentanyl


  • Potent analgesic 100 times more than morphine
  • Metabolized in the liver and excreted in the urine
  • Produce respiratory depression so use in caution with COPD
  • Cause less nausea and vomiting
  • Can be reversed by naloxone
• نﯾﻓروﻣﻟا


  1/10 يوﻗ ﻞﺜﻣ ، نﯾﻓروﻣﻟا ﻦﻜﻟو ﮫﺘﯿﻟﺎﻌﻓ ﺔﻠﺛﺎﻤﻣ
• Pharmacokinetics


  Well absorbed orally, bioavailability 50%, Effects appear in 10-15 min. after oral absorption, On parenteral administration action lasts for 2-3 Hrs, Metabolized in liver, Excreted in urine
• Fentanyl


  Potent analgesic 100 times more than morphine, Metabolized in the liver and excreted in the urine, Produce respiratory depression so use in caution with COPD, Cause less nausea and vomiting, Can be reversed by naloxone, Dose 1-5 microgram / kilogram i.v
• Fentanyl is preferred due to its rapid onset and short duration of action
• Remifentanil


  Remifentanil (marketed by Abbott as Ultiva) is a potent ultra-short-acting synthetic opioid given to patients during surgery for pain relief and adjunctive to an anesthetic, Remifentanil is a specific mu-type-opioid receptor agonist which means it reduces sympathetic nervous system tone, and causes respiratory depression and analgesia
• Remifentanil


  • Rapid onset and peak effect and ultrashort duration of action, The opioid activity of remifentanil is antagonized by opioid antagonists such as naloxone, The analgesic effects of remifentanil are rapid in onset and offset, Its effects and side effects are dose dependent and similar to other opioids (Hypotension is the most common side effects)
• Anti-autonomic drugs


  They contain either anticholinergic or beta1blocker
• Anticholinergic drugs used in premedication

  • Atropine, hyoscine, Glycopyrrolate
• Atropine


  • Vagal inhibition (tachycardia), CNS stimulation, Antisialagogues (decrease salivation), Dose 0.3 – 0.4 mg iv, May cause central anticholinergic syndrome (restlessness, agitation, somnolence, convulsion) and this can be reversed by physostigmine
• Hyoscine


  • Less vagal inhibition effect with more effect on salivation but produce sedation and amnesia so should be avoided in elderly
• Glycopyrrolate


  • No central action because it does not cross the blood brain barrier, Longer duration and less tachycardia, Produces dry mouth, Produces mydriasis (dilation of eye pupil) except Glycopyrrolate
• Antiemetic drugs


  Drugs used to decrease the incidence of nausea and vomiting, the most commonly used are: ondansetron and Metoclopramide (plasil)
• Antiemetic drug dose


  0.15 to 0.3 mg /kg and last for 12 hours