1. Anesthesia

2. “Nothing in life is to be feared. It is only to be understood.”
Marie Curie (` )

3. General anesthesia Regional anesthesia Monitored anesthesia care

5. General anesthesia

7. “Before him surgery was agony.”
Epitaph on a monument honoring W. Morton

9. General anesthesia
The goals of general anesthesia: - Mandatory: -amnesia/sedation/hypnosis -analgesia -maintenance of homeostasis - Optionally: -muscle relaxation

10. General anesthesia indications
Indications based on the surgical procedure:
-surgical procedures requiring analgesia and muscle relaxation, that cannot be performed using regional anesthesia techniques: upper abdominal surgery, thoracic surgery, head and neck surgery, shoulder surgery etc.
-surgical procedures that significally interfere with vital functions: neurosurgery, thoracic surgery, cardiac surgery, surgery of the aorta etc.

12. General anesthesia indications
Indications based on the patient condition:
-different pathologies or ongoing treatments that make the regional anesthesia tachniques contraindicated: the patients with coagulation disorders, anticoagulant treatments, infections or other lesions in the area where a regional anesthesia procedure would be performed;
-systemic diseases with definite functional limitations: the patient with respiratory insufficency, shock, coma, major hydroelectrolytic or acido-basic imbalance.

14. Drugs used for general anesthesia
Hypnosis Analgesia Muscle relaxation Maintenance of homeostasis can all be achieved by administering one or more drugs

15. Drugs used for general anesthesia
Inhalatory anesthetics:
-gaseous form
nitrous oxide
-volatile liquids
halothane, isoflurane, sevoflurane si desflurane
The advantage of entering and leaving the body by ventilation with minimal metabolization.
They result in sedation, analgesia and light muscle relaxation.

16. Each inhalatory anesthetic has its own specific MAC.
The potency of an inhalatory anesthetic
MAC (minimal alveolar concentration)
= the alveolar concentration of the anesthetic that abolishes the movements caused by the skin incision in 50% of the patients
Each inhalatory anesthetic has its own specific MAC.
Modern anesthesia - new types of MAC:
MAC intubation ( MAC that facilitates the intubation in 50% of the patients);
MAC bar (MAC that abolishes the hemodynamic response in 50% of the patients);
MAC awake (MAC at which awakening occurs in 50% of the patients).

17. Inhalant anesthetic
Class
Concentration in balanced anesthesia
Advantages/disadvantages
Side effects
Nitrous oxide
Gaseous
40-66%
Light analgesia
Accumulation in airway spaces
Risk of hypoxemia
Euforia
Halothane
Volatile
1,5-2%
Bronchodilatation
Slow dynamics
Cardio-vascular depression
Isoflurane
Medium dynamics
Vasodilatation
Sevoflurane
2-3%
Fast dynamics
Cardio-vascular stability
Compound A
Desflurane
6-8%
Airway irritant
Special vapporiser
Sympathetic stimulation

18. Intravenous anesthetics:
Short acting:
Barbiturates → metohexital
thiopental, tiamital
Imidazolic compounds → etomidate
Alkylphenols → propofol
Steroids → eltanolone
Long acting:
Ketamine
Benzodiazepines → diazepam, midazolam

19. THIOPENTAL: -very rapid induction; maximal effect in 40 s;
-superficial anesthetic sleep;
-NO an analgesic effect;
-weak muscle relaxation.
Administration: slow i.v.
Side effects: risk of respiratory and circulatory depression

20. PROPOFOL
-very liposoluble fatty acid;
-hepatic metabolisation in great extent → short effect;
Pharmacodynamic action:
-pharmacologic effects similar with those of Thiopental;
-less residual effects.

21. KETAMINE Pharmacodynamic action: Dissociative anesthetic: - dissociation from the environment - superficial sleep - strong analgesia Advantages:-No respiratory depressant effect; -hemodynamic stability by the release of catecholamines -bronchodilatatory effect

22. Hypnotic
Class
Induction dose
Single dose duration of action
Side effects
Thiopental
Short acting barbituric
2-4 mg/kg
5-10 min
Arterial hypotension, respiratory depression, tachycardia, decreases the cardiac output
Propofol
Alkylphenol
1-2 mg/kg
Arterial hypotension, respiratory depression, tachycardia
Etomidat
Imidazolic compound
0,3 mg/kg
Adrenal glad inhibition
Diazepam
Benzodiazepines
10-60 min
Interindividual response variability
Midazolam
0,2-0,3 mg/kg
5-15 min
Respiratory depression

23. Analgetics:
Opioids:
-the class of analgesics with the broadest intra-anesthetic utilisation;
-profound dose-dependant analgesia;
-in spite of their quasi-constant use during general anesthesia, the opioids are not anesthetics because the loss of consciousness is not a regular effect
-they regularly result in respiratory dose-dependent depression. Cardiovascular depression is a variable effect.

24. Opioids
Class
Medium dose
Single dose duration of action
Side effects
Morphine
μ Agonist
0,2 mg/kg
30-60 min
Respiratory depression, sedation. hTA, bradycardia
Pethidine
μ/Δ Agonist
1 mg/kg
20-30 min
Sedation, nausea/vomiting, HTA, tachycardia
Fentanil
5-15 μg/kg
20 min
Respiratory depression
Sufentanil
0,3-1 μg/kg
Alfentanil
5-50 μg/kg
Remifentanil
0,5-1 μg/kg
1-3 min
Buprenorphine
Agonist/ antagonist
0,3 mg
3-4 ore
Ceilling effect

25. Muscle relaxants:
-substances that act at the neuromuscular junction level and prevent the transmission of the physiologic stimulus for the muscular contraction;
-NO action on the CNS, NO loss of consciousness, NO analgesia;
-utilized for the facilitation of the airway instrumentation, of mechanical ventilation and of the surgical intervention;
-results in alveolar hypoventilation or apnea by the action on the respiratory muscles;
-minimal cardio-vascular effects.

26. Muscular relaxant
Class
Intubation dose
Single dose duration of action
Particular instructions
Succinylcholine D
1-1,5 mg/kg
10-15 min
Full stomach
Pancuronium ND
0,1 mg/kg
30-40 min
Bradycardia
Vecuronium
0,08 mg/kg
20-30 min
Cardiac affections
Atracurium
0,5 mg/kg
20 min
Kidney failure
Cisatracurium
0,2 mg/kg
Mivacurium
Short interventions
Rocuronium
0,6-0,9 mg/kg
30-60 min

27. Anesthesia apparatus

28. Anesthesia Apparatus Components: -connection with the sources
of medical fluids
-flowmeters
-vaporizers
-anesthetic circuit
-CO2 scavenger system
-balloon ventilation system
-overpressure valve
-mechanical ventilation module
-emergency oxygen delivery circuit

29. -ventilation parameters setting module;
-ventilation parameters and inhalation anesthetics monitoring module;
-alarm module;
-vacuum system (sucction).

31. Intraanesthesic monitoring

32. Intraanesthesic monitoring
Standard I:
-the presence in the room of an anesthesiologist or a qualified staff member throughout the duration of the anesthesia.
Standard II:
-oxygenation: inspiratory oxygen concentration (FiO2), pulsoxymetry (SpO2);
-ventilation: clinical evaluation, auscultation, capnography;
-circulation: electrocardioscopy (continuous), noninvasive arterial blood pressure and pulse measurement;
-body temperature.

33. Central, peripheral Monitoring Respiratory
Airway pressure, tidal volume, minute ventilation, respiratory rate, O2/CO2 inspiratory concentration, concentration of volatile anesthetic agent, pulsoxymetry
Cardiovascular
Non-invasive arterial pressure, multiple leads ECG, computerized analysis of ST segment, central venous pressure, pulmonary artery pressure (systolic, medium, diastolic, wedge) cardiac output, extra-vascular pulmonary water, peripheral vascular resistance, ScvO2, SvO2.
Hypnosis
BIS (bispectral index)
Muscle relaxation
Peripheral nerve stimulator
Renal
Diuresis
Temperature
Central, peripheral
Acid - base equilibrium
Blood gas analysis
Electrolytes
Na, K, Cl, Ca
Haematological analysis, coagulation studies
Platelets, aPTT, INR
Oxygen transportation
Hb, Ht, cardiac output, SaO2, PaO2
Metabolic
Glucose

34. Preanesthetic visit

35. Preanesthetic exam: -psychological preparation of the patient;
-clinical and laboratory evaluation of the patient;
-asignement to an anesthetic risk group (ASA scale)
-choosing the anesthetic technique and obtaining the informed consent;
-set up of an anesthetic plan.
Risk I
Patient without systemic diseases
Risk II
Patient with systemic diseases without functional limitation
Risk III
Patient with systemic diseases with functional limitation
Risk IV
Patient with uncompensated systemic disease
Risk V
Dying patient
Risk VI
Brain dead patient, organ donor E
Emergency procedure

37. Optimizing the patient status:
-the correction of dysfunctions and diseases in the preoperative period.
Premedication :
-reduced anxiety and reduced need for intra- operative anesthetics;
-decreasing certain risks (parasympathetic reflexes, the risk of aspiration);
-the facilitation of postoperative analgesia.

38. Phases of general anesthesia
Induction phase:
-the period of transition from the state of conscious to the state of general anesthesia;
-CNS depression, ventilatory, cardiovascular depression, muscle relaxation;
-securing the airway.
Maintenace phase:
-providing the adequate depth of anesthesia by administering anesthetics, analgesics and muscle relaxant agents.
Emergency phase:
-the interruption of the administration of all volatile or intravenous anesthetic agents;
-the antagonisation of the muscle relaxant drug.

46. General anesthesia techniques
Balanced anesthesia;
Intravenous anesthesia;
Volatile anesthesia;
Combined techniques of general and regional anesthesia:
-general anesthesia + epidural anesthesia.

47. General anesthesia complications
Respiratory
Hypoxemia, hypercapnia laryngeal spasm, bronchospasm, aspiration, ARDS, atelectasis
Cardio-vascular
High/low blood pressure, tachy/bradycardia, myocardial ischemia, arrhythmia , hypovolemia, low cardiac output
CNS
Convulsions, shivers, post anoxic encephalopathy, paresis by compression or elongation of peripheral nerves
Digestive
Vomiting or regurgitation, hiccup
Renal
Oligo/anuria, urinary retention, pre - renal failure
Metabolice
Hyper/hypoglycemia, malignant hyperthermia
Hidro-electrolitics
Extracellular space expansion (interstitial oedema), hypo/hyperkalemia, hypocalcemia
Acid-base
Hypercloremic metabolic acidosis, lactacidemic
Coagulation
Thrombocytopenia, dilutional coagulopathy, deep venous thrombosis
Allergical
Cutaneous eruptions, Quincke oedema, bronchospasm, anaphylactic shock
Cutaneous
Decubitus injury, accidental burns

48. Regional anesthesia
Subarachnoid (spinal)
Epidural
Sequential
Caudal

49. Regional anesthesia Indications:
-the area can be anesthetised using regional blocks;
-the surgical procedure does not affect the vital functions;
-patient's informed consent;
Contraindications:
-patient's refusal;
-active coagulation disorders or anticoagulant treatment;
-infections or haematoma at injection site;
-neurological deficit and lack of cooperation.

50. analgesia muscle relaxation sympathetic blockade Spinal Anethesia:
-sympathetic blockade: hypotension, bradycardia, urinary retention;
-hypovolemia is an absolute contraindication of spinal anesthesia;
-epidural analgesia is the standard procedure for peripartum analgesia;
-complications: systemic (high spred of anesthetic- total spinal anesthesia or systemic toxicity), headache.

51. Local anesthetics Amides Esters Lidocain Prilocain Procain
Mepivacain Etidocain
Tetracain
Bupivacain Ropivacain
Benzocain
Clinical use of local anesthetics
Central regional anesthesia/analgesia
Regional intravenous anesthesia
Peripheral nerve block or plexus
Infiltration anesthesia
Local anesthesia
Blocking of thehemodynamic response during tracheal intubation
in regional anesthesia we frequently use the combination between a local anesthetic and adrenaline, an opioid or clonidine, increasing the duration and quality of the block

52. During regional anesthesia – mandatory equipments:
Anesthesia delivery system
Equipments and materials for airway management
Oxygen source
Monitoring: ventilation, oxygenation, circulation, blood pressure, EKG.

53. Spinal anesthesia (sub-arachnoid block)

58. Epidural anesthesia

62. Sequential (combined) anesthesia
spinal / epidural

64. Caudal anesthesia

66. Plexus anesthesia or peripheral nerves blockade
Single-shot
Catheter

68. Local anesthesia contact topical - skin, mucous membrane application
tissue infiltration

69. Monitored anesthesia care

71. Monitored anesthesia care
- intravenous administration of anxiolytic, sedative, analgesic and amnesic drugs either isolated or supplementing a regional anesthesia procedure;
- indicated in: painful diagnostic or therapeutic procedures or supplementing a inappropiate regional block;
- the CPR equipments must be close-by at all times;
- complications: respiratory depression with hypoventilation and loss of airway protection.