Embed Size (px)
Citation preview
Practice of anesthesiology
• Practice of anesthesiology is the practice medicine
• Preoperative evaluation
• Intraoperative management
• Postoperative care
• Anesthesiology is perioperative medicine
Practice of anesthesiology• Preoperative evaluation and patient preparation• Intraoperative management - General anesthesia Inhalation anesthesia Total IV anesthesia - Regional anesthesia & pain management Spinal, epidural & caudal blocks Peripheral never blocks Pain management (acute and chronic pain)• Postanesthesia care (PACU management)• Anesthesia complication & management• Case study
Preoperative anesthetic evaluation
• History 1. Current problem 2. Other known problem 3. Medication history: allergies, drug intolerances, present therapy, alcohol, tobacco 4. Previous anesthetics, operations 5. Family history of anesthesia 6. Review of organ systems 7. Last oral intake• Physical examination: VS, airway, CV, lung, neuro• Lab evaluation, chest X-ray, ECG• ASA classification
Physical status classification
• Class I: A normal healthy patients• Class II: A patient with mild systemic disease (no functional limitation)• Class III: A patient with severe systemic disease (some• functional limitation)• Class IV: A patient with severe systemic disease that is a constant threat to life (functionality incapacitated)• Class V: A moribund patient who is not expected to survive without the operation• Class VI: A brain-dead patient whose organs are being removed for donor purposes• Class E: Emergent procedure
Anesthetic planPremed Type of Intraoperative Postoperativeanesthesia management managementGeneral Monitoring Pain control Airway management Positioning Intensive care Induction Fluid management postop ventilation Maintenance Special techniques Hemodynanic monit Muscle relaxation
Regional Technique Agents
Monitored anesthesia care Supplement oxygen Sedation
Preoperative management
• Diabetes: hyperglycemia or hypoglycemia• Hypertension• Renal failure: HD patients – potassium level • Asthmatic patients• Chronic steroid use• Pregnant test• Preop medication: Sedation-benzodiazepine Aspiration precaution-H2 blockers, metoclopramide Antibiotics
NPO status
• NPO, Nil Per Os, means nothing by mouth
• Solid food: 8 hrs before induction
• Liquid: 4 hrs before induction
• Clear water: 2 hrs before induction
• Pediatrics: stop breast milk feeding 4 hrs
before induction
General Anesthesia
• Monitor• Preoxygenation• Induction ( including RSI & cricoid pressure)• Muscle relaxants• Mask ventilation• Intubation & ETT position comfirmation• Maintenance• Emergence
Airway examMallampati classification Class I:
uvula, faucial pillars, soft palate visible
Class II: faucial pillars, soft pillars visible
Class III: soft and hard palate visible
Class IV: hard palate visible
Sniffing position
Mask and airway tools
Mask ventilation and intubation
Oral and nasal airway
Intubation
Intubation
Laryngeal view
Laryngeal view scoring system
Difficult airway
Fiberoptic scope intubation
Trachea view Carina view
Glidescope
Fast track LMA
LMA
Difficult Airway Algorithm
Induction agents
• Opioids – fentanyl
• Propofol, Thiopental and Etomidate
• Muscle relaxants:
Depolarizing
Nondepolarizing
Induction
• IV induction
• Inhalation induction
• Rapid sequence induction
General Anesthesia
• Reversible loss of consciousness
• Analgesia
• Amnesia
• Some degree of muscle relaxation
Intraoperative management
• Maintenance
Inhalation agents: N2O, Sevo, Deso, Iso
Total IV agents: Propofol
Opioids: Fentanyl, Morphine
Muscle relaxants
Balance anesthesia
Intraoperative management
• Monitoring• Position – supine, lateral, prone, sitting, Litho• Fluid management - Crystalloid vs colloid - NPO fluid replacement: 1st 10kg weight- 4ml/kg/hr, 2nd 10kg weight-2ml/kg/hr and 1ml/kg/hr thereafter - Intraoperative fluid replacement: minor procedures 1-3ml/kg/hr, major procedures 4- 6ml/kg/hr, major abdominal procedures 7-10/kg/ml
Intraoperative managementEmergence
• Turn off the agent (inhalation or IV agents)
• Reverse the muscle relaxants
• Return to spontaneous ventilation with adequate ventilation and oxygenation
• Suction upper airway
• Wait for pts to wake up and follow command
• Hemodynamically stable
Postoperative management
• Post-anesthesia care unit (PACU) - Oxygen supplement
- Pain control
- Nausea and vomiting
- Hypertension and hypotension
- Agitation
• Surgical intensive care unit (SICU) - Mechanical ventilation
- Hemodynamic monitoring
General Anesthesia Complication and Management
• Respiratory complication - Aspiration – airway obstruction and pneumonia - Bronchospasm - Atelectasis - Hypoventilation
• Cardiovascular complication - Hypertension and hypotension - Arrhythmia - Myocardial ischemia and infarction - Cardiac arrest
General AnesthesiaComplication and Management
• Neurological complication - Slow wake-up
- Stroke
• Malignant hyperthermia
Regional Anesthesia
• No absolute indication for spinal or epidural anesthesia
• May improve outcome in selected situations• Blunt stress response to surgical stimulation• Decrease intraoperative blood loss• Lower the incidence of postoperative
thromboembolic events• Decrease M&M in high risk patients• Extend analgesia into postoperative period
Posterior and lateral view of spinal column
Spinal cord terminates
Human sensory dermatomes
Spinal anesthesia
• Patient position• Approachs: Midline & Paramedian• Technique• Monitoring during spinal anesthesia• Single dose spinal anesthesia• Continuous spinal anesthesia• Complications• Contraindications• Common local anesthetics for spinal anesthesia Lidocaine, Bupivacaine, Tetracaine, Ropivacaine
Physiology of Spinal Anesthesia
• LA blocks conduction of impulses along all with which it contacts
• Autonomic and pain fibers block - early
• Motor fibers block - late
Position
• Sitting position Sit straight first Chin on chest Arms resting on knees Footstool/table to support feet
Back curving like banana or shrimp • Lateral position Shoulders perpendicular to bed Positioned with hips on edge of bed Knee chest position and back curving
Approach
• Median approach• Most common
• Needle or introducer is placed midline
• Perpendicular to spinous processes
• Slightly cephalad
• Paramedian approach• For pts who cannot adequately flex
• Needle placed laterally(1.5cm) and slightly caudad to center
• Needle aimed medially and slightly cephalad
Midline approach to subarachnoid space
Technique
• Anatomic landmark identified• Superior iliac crests at L4 level• Spine is palpated• A sterile field estabolished• Skin wheel with LA• Introducer inserted and spinal needle passed• CSF presence• LA injection
Procedure
Monitoring
• Respiration
• Heart rate
• Blood pressure
LA & Concentration T10 level T4 level Duration Duration upper abd lower abd plain with epiBupivacaine 0.75% 12-14mg 12-18mg 90-120min 100-150min
Tetracaine 1% 10-12mg 10-16mg 90-120min 120-240min
Lidocaine 5% 50-75mg 75-100mg 60-75min 60-90min
Ropivacaine 02-1% 12-16mg 16-18mg 90-120min 90-120min
Common local anesthetics
Factors affecting spread of LA solution
• Baricity of LA solution
• Position of patient
• Concentration volume injected
• Level of injection
• Speed of injection
Assessing the level of block
Complications
• Common complications Postdural punture headache
Transient radicular syndrome
Backache
Hypotension
Itching
Complications
• Less common complications Cauda equina syndrome Total spinal Urinary retention Cardiac arrest Spinal/epidural hematoma Aseptic meningitis Bacterial meningitis Cranial nerve palsies
Contraindications
• Relative contraindications Hypovolemia
Preexisting neurologic disorders
Chronic back pain
Localized infection peripheral to regional site
Patients taking ASA, NSAID, dipyridamole
Contraindications
• Absolute contraindications Patient refusal
Infection at puncture site
Generalized sepsis
Severe coagulation abnormalities
Raised ICP
Epidural Anesthesia• Position• Approach: midline & paramedian• Location: cervical, thoracic, lumbar• Technique• Monitoring• Single dose - pain management• Continuous epidural - anesthesia & analgesia• Complication• Contraindication• Common LA for epidural anesthesia & analgesia Bupivacaine and ropivacaine
Epidural Approach
Epidural Anesthesia Kit
Loss of resistance technique
Epidural Catheter Placement
Epidural Catheter Placement
Epidural Catheter placement
Epidural Catheter Placement
Complications• Similar to spinal anesthesia
• Wet tap – postpuncture headache
• Total spinal anesthesia – apnea, hypotension, bradycardia
Common LA for Epidural Anesthesia• Bupivacaine: 0.125-0.25% for analgesia
0.5% for anesthesia
• Ropivacaine: 0.2% for analgesia
0.5-1% for anethesia
• Lidocaine: 2% for anesthesia
Caudal Anesthesia
• Common regional technique in pediatric pts
• Caudal space is sacral portion of epidural space
• Needle penetration of sacrococcygeal ligament from sacral hiatus
• Caudal anesthesia technique is difficult or impossible due to calcification of sacrococcygeal ligament
Caudal Technique
Caudal Anesthesia
Peripheral Nerve Block
• Injection of LA near the nerves to block sensation and motor function
• Can be used as primary and sole anesthetic technique for selective surgery
• Can be used for postop pain control
Common Nerve Block
• Brachial plexus block - Interscalene approach
- Axillary approach
- Infroclavicular approach
• Intravenous regional anesthesia (Bier block)• Lumbar plexus block - Femoral block
• Sacral plexus block - Sciatic nerve block
Anatomy of Brachial Plexus
Brachial Plexus Block-Interscalene Approach
Lumbar and Sacral Plexus Distribution
Femoral and Sciatic Nerve block
Peripheral Nerve Block
• Complications: - Intravascular injection and toxicity
- Chronic paresthesias and nerve damage
- Respiratory failure due to phrenic nerve block
- Others: infection, bleeding, allergic reaction
- The greatest immediate risk is systemic toxicity
from inadvertent intravascular injection
Local Anesthetic Toxicity
Peripheral Nerve Block
• Contraindications: - Uncooperative patient
- Coagulopathy
- Local skin infection
- Peripheral neuropathy
- Local anesthetic toxicity
Pain Management
• Most common symptom that brings patients to see a physician
• Pain is “an pleasant sensory and emotional experience associated with actual or potential tissue damage” (IASP)
• Component of anesthesia practice outside OR • “Nociception” (latin for harm or injury) is
used to describe the neural response only to traumatic or noxious stimuli
Pain Management• Classification: Persistent time: acute and chronic pain
Pathophysiology: nociceptive and neuropathic pain
Etiology: postoperative, cancer pain
Affected area: headache, low back pain
Presentation: local, radiate, diffuse
Characteristic: burning,sting,blunt,distended,angina
Pain Evaluation
(VRS)
Pain Management
• Medicine for Acute pain: NSAIDS: Ibuprofen, Ketorolac, Naproxen
Opioids: Morphine, Fentanyl, Meperidine,
Hydromorphone
Local anesthetics: Lidocaine, Bupivacaine,
Ropivacaine
Pain Management
• Administration route of pain medicine: - Oral - opioids, NSAIDs
- IV - single dose IV push or PCA(opioids, NSAIDs)
- IM - injection (opioids, NSAIDs)
- Local infiltration with LA
- Peripheral nerve block - intercostal, intrapleural
- Epidural - continuous or PCA with opioids, LA
- Intraspinal route with opioids
Pain Management - Chronic Pain
• Psychological and behavioral factors play a major role in chronic pain
• Psychology, neurosurgery consultation• Antidepression • Treatment of insomnia• Muscle relaxant • Oral NSAIDs and/or opioids• Neural blockade - somatic, sympathetic blocks• Radiofrequency ablation & cryoneurolysis• Spinal cord stimulation• Intraspinal pump for opioids and/or NSAIDs• Physical therapy: acupuncture
Case Study
• 73 years old male presents for 6 cm AAA repair
• PMH: CAD, HTN, DM
• PSH: CABG, appendectomy
• Social Hx: smoke 1ppd for 50 years
• Current Med: Nitro patch, ASA, lisinopril, clonidine, glucophage
Case Study
• Preop evaluation:
- Current medical problems: CAD, HTN, DM,
long term smoke
- Past anesthesia history
- Preop test: ECG, CXR, cardiac function,
pulmonary function
- Preop lab: CBC, Chemistry, coagulation
Case Study
• Preop evaluation:
- Airway exam
- NPO
- Home med on the day of operation
- Blood glucose on the day of operation
- Premedication
- Blood products
Case Study
• Intraoperative management:
- Monitor:
Noninvasive: ECG, pulse O2 saturation, BP
Invasive: A-line, CVP, PAC
Urine output
- Induction and intubation
- Fluid management
Case Study
• Intraoperative management: - Aortic clamp increases afterload, significantly increases BP, may cause myocardia ischemia and heart failure, vasodilator may needed - Kidney protection: furosemide, mannitol - Aortic clamp release decreases afterload, significantly decreases BP, vasoconstrictor, calcium usually are used
Case Study
• Postoperative care:
- Postop ventilation:
Ventilator setting
Weaning from ventilator
- Hemodynamic monitor
- Lab: H/H, electrolytes, coagulation
Case Study
• Complication:
- Bleeding: intra & postoperative
surgical & nonsurgical
- Cardiac complication
- Respiratory failure
- Renal insufficency
