Anesthesia Revision E6.5.pdf

Anaesthesia Revision 1 01 1 ANAESTHESIA REVISION 1 ----- Active space ----- Pre Anaesthetic Checkup (PAC)...

Anaesthesia Revision 1 01 1 ANAESTHESIA REVISION 1 ----- Active space ----- Pre Anaesthetic Checkup (PAC) 00:00:24 Past medical history : Co-morbid condition Concerns Continue all except ACE inhibitors & ARBs (as they can cause se- Hypertension vere hypotension). Target glucose level : 120-200 mg/dl. Skip OHGAs & insulin on day of Sx. Diabetes Mellitus Long acting insulin : Reduced to 1/3rd. SGLT2 Inhibitors : Stopped 24 hrs prior (Chance of euglycemic ketoacidosis). Epilepsy Continue antiepileptics. Avoid Enflurane, Methohexitone (seizure provoking). Thyroid disorders Continue thyroid supplementation & anti thyroid drugs. MAO inhibitors (Interact with synthetic opioids → hypertensive crisis) : Stopped 3-4 weeks prior. Psychiatry Lithium or Mg2+ interact & prolong muscle relaxation : Continued depending on patient condition. Low dose Aspirin (60-75 mg) : Can be continued. High dose (150-300 mg) : Stop 3 days prior. Clopidogrel & warfarin : Stop 5-7 days prior. After stopping other anticoagulants/antiplatelet drugs, bridged with LMWH : Past H/O MI - Prophylactic dose : Stop 12 hours prior. - Therapeutic dose : Stop 24 hours prior. - Regular heparin : Stop 6 hours prior. Ticlopidine : Stop 10 days prior. All other cardiac drugs : Continued. Estrogen containing pills : High risk category (Stop 4 weeks prior) OC pills & Low risk (can be continued). Steroid therapy Continue steroids. Herbal medicine Check LFT & wait for 1 to 2 weeks if deranged. On NSAIDS Stop 24 to 48 hours prior to surgery. On sildenafil Stop 24 to 48 hours prior (intractable hypotension). On diuretics Except thiazide, stop all drugs (monitor S. electrolytes). Anaesthesia Revision 1.0 Marrow 6.5 2023  2 01 Anaesthesia ----- Active space ----- Personal history : Condition Concern Smoking Stop 6 to 8 weeks. chance of bronchospasm (presents as wheeze) : Treatment : Beta 2 agonist (Salbutamol). chance of laryngospasm (Stridor→ Desaturation) : Treatment : 100 % O2. Propofol. Succinyl choline (severe cases). Alcohol Stop 24 to 48 hours. Check LFT. Tobacco chewing Chances of difficult intubation. Allergy history → Anaphylactic shock : Most common presentation. Etiology : Antibiotics, latex, Muscle relaxants, local anaesthetics. Pathophysiology : Release of histamine. Clinical presentation : Sudden unexplained tachycardia. Hypotension. Increased airway resistance. Edema of face, lips, tongue etc. Wheeze. Management : Adrenaline (1 ml of 1 : 10000 IV / 0.5 ml of 1 : 1000 S/C or IM). Family history → Malignant hyperthermia : Severe mortality under general anaesthesia. Etiology : All inhalational anaesthetics & succinylcholine (only in those with family history/muscular disorders). Pathophysiology : Mutation of Ryanodine receptors at sarcoplasmic reticulum. Clinical presentation : Sudden unexplained tachycardia. Hypertension. Increased body temperature. Increased ET CO2. Ventricular fibrillation (d/t release of K+). Sudden cardiac arrest. Anaesthesia Revision 1.0 Marrow 6.5 2023  Anaesthesia Revision 1 01 3 Management : ----- Active space ----- Stop inhalational agents. 100 % O2. Dantrolene sodium. Calcium gluconate, salbutamol, insulin + dextrose (for management of hyperkalemia. Postoperative complication : Acute kidney injury (myoglobin release). ASA grading : ASA grading I Normal healthy patient. II Mild disease with no functional limitations. Eg : Asthma. III Moderate disease with functional limitations. Eg : CKD, CLD. IV Severe disease which is threat to life. Eg : Unstable angina, MI. V Moribund patient who is not expected to survive >24 hrs. VI Brain dead patient. Investigations : 1. CBP : Minimum acceptable Hb : 8 gm/dl. 2. Platelet count : For invasive procedure : 50,000 (minimum acceptable count). For surgery : 80,000 - 1,00,000. 3. ECG. 4. CXR. Risk stratification 00:26:10 CVS risk stratification : High risk for post op cardiac events : 1. High-risk surgery. 2. H/o Ischemic heart disease. 3. H/o congestive heart failure. 4. H/o cerebrovascular disease. 5. Diabetes mellitus requiring insulin. 6. Creatinine > 2.0 mg/dL. When should be patient operated if he has coronary stenting : a. > 30 days after bare metal stent. b. 6 months for drug eluting stents. After URTI : wait for 6 weeks. Anaesthesia Revision 1.0 Marrow 6.5 2023  4 01 Anaesthesia ----- Active space ----- Pre operative instructions 00:27:13 Pre medications → (5A’s) : 1. Anxiolytic : Short acting benzodiazepines. 2. Anticholinergics : Atropine /Glycopyrrolate (reduce airway secretions). 3. Anti emetics → High risk group include : Females. Fasting guidelines : History of motion sickness/ opioid use. 1. Adult : 6-8 hours. Laparoscopy. 2. Child : Middle ear surgery. 2 hour : Clear fluids. Ophthalmic surgery. 4 hour : Breast milk. 4. Analgesics. 6 hour : Solids. 5. Antibiotics. Monitoring of patient 00:30:09 Monitoring the patient Basic Advanced CNS CVS Resp Neuro Temperature Blood loss muscular CNS monitoring : Bispectral index : Assess depth of anaesthesia. Working principle : Analyse EEG wave forms. Target value : 40-60. CVS monitoring : 1. Pulse rate/ heart rate. 2. Non invasive blood pressure monitoring (NIBP) : Oscillatory method : Automatic NIBP machine. 3. ECG : Monitor lead 2 : To detect arrhythmia. Monitor lead V3, V4, V5 : To detect ischemia, infarction. 4. Invasive blood pressure monitoring (IBP) : MC site : Radial artery. Allens test : To check for adequate collateral circulation. Femoral artery : Used for major surgeries. Anaesthesia Revision 1.0 Marrow 6.5 2023  Anaesthesia Revision 1 01 5 5. Central venous pressure (CVP) monitoring : ----- Active space ----- Normal CVP value : 0 - 5 cm. M/C site : Internal jugular vein. Function : a. Detect right sided heart function. b. Fluid status. Low CVP + Low BP Hypovolemia Triple lumen catheter for CVP High CVP + Low BP Right heart failure. Other sites : Subclavian vein (pneumothorax), femoral vein (infection). Not used for rapid resuscitation. 6. Pulmonary capillary wedge pressure (PCWP) : Function of left side of heart. Normal : 12-16 cm. Invasive procedure. Complication : Pulmonary artery rupture. 7. Echocardiography. Swan Ganz catheter Respiratory monitoring : Pulse oximeter : Principle : Beer Lambert’s law. Emits : Pulse oximeter Red light : Reduced Hb. Infrared light : Oxygenated Hb. CO poisoning (fire accidents) : Falsely elevated values. Meth Hb, dye, henna on hand, jaundice, thick skin : Falsely low values. Capnography : Monitor exhaled CO2. Functions : a. Surest sign of intubation. b. Recommended to monitor CPR performance. Capnograph c. Diagnose malignant hyperthermia. d. Diagnose endotracheal tube disconnection. e. Diagnose venous air embolism. III IV/0 II Waveforms : I I Normal : 1. Phase 1 : Exhalation of gases from dead spaces. 2. Phase 11 : Gas exhaled from upper alveoli. 3. Phase 111 : Gas exhaled from middle & lower alveoli. 4. Phase 1V/0 : Inspiratory phase. Anaesthesia Revision 1.0 Marrow 6.5 2023  6 01 Anaesthesia ----- Active space ----- Variations of Waveforms Rebreathing/ exhausted sodalime (elevated baseline/phase 1) Spontaneous breathing Normal phenomena Bronchospasm/COPD (shark fin pattern) (Increased upstroke of phase III). Cardiogenic oscillations (pediatric) Hypoventilation Curare cleft : Notch in phase 111. Patient recovering from effect of muscle relaxants. Hyperventilation Malignant hyperthermia : Leaky sampling line : (step ladder pattern). (2 plateaus in phase 111). Incompetent inspiratory valve Single lung transplant : (2 peaks in phase 111). Accidental extubation/ sudden disconnect Esophageal intubation Anaesthesia Revision 1.0 Marrow 6.5 2023  Anaesthesia Revision 1 01 7 Neuro- muscular monitoring : ----- Active space ----- M/C : Ulnar nerve. Patterns of stimulus : 1. Single twitch stimulation : Cannot differentiate between DMR& NDMR. 2. Train of four (TOF) : 4 supramaximal stimulus at every 0.5s (2Hz). If TOF Ratio > 0.9 → Safe for extubation. TOF Ratio = 4th amplitude 1st amplitude 3. Tetanic stimulation : Used for monitoring of deeper blocks (painful). 4. Double Burst Stimulation : Less painful. Normal NDMR DMR Train of Four Tetanic Stimulation Features Constant Fading Constant (Normal amplitude) (Diminishing amplitude) (Reduced amplitude) Core body temperature monitoring : Monitoring sites Procedure Nasopharynx & tympanic membrane CNS surgery. Pulmonary capillary temperature CABG. (most accurate) Mid oesophageal temperature GI surgery. (M/c done) Intermediate between core & Rectal temperature surface temperature. A/C frostbite. Anaesthesia Revision 1.0 Marrow 6.5 2023  8 02 Anaesthesia ----- Active space ----- ANAESTHESIA REVISION 2 Airway Examination 00:00:26 Examination Inference Predictors for difficult Obesity, Bearded, Elderly, Snorer, Edentulous, Pregnant intubation (OBESE Pregnant lady). Mouth opening Finger breath technique (Normal = 3 fingers). Normal : 12-35˚ ( 5 sec. Able to hold tongue depressor b/w central incisors. Train of four ratio > 0.9 : Guaranteed recovery. Anaesthesia Revision 1.0 Marrow 6.5 2023  Anaesthesia Revision 3 03 17 Local anaesthetics 00:50:51 ----- Active space ----- Amino amides Amino esters Metabolised in liver Metabolised by plasma esterases (except articaine). (except cocaine). Lignocaine, bupivacaine, ropivacaine Procaine, chlorprocaine. Structurally similar to PABA. Can cause allergic reactions Mechanism of action : Unionised form diffused through cell membrane → Converted to ionised formed by low intracellular pH → Voltage gated sodium channel blockade. Sequence of blockade in regional anaesthesia : B > C > A nerve fibers. Autonomic > Pain (sensory) > Motor. Factors affecting action of LA : Quick Onset ↑ Duration Absorption ↑Concentration of drug ↑Dose of drug. Maximum PKa : Close to body pH Adrenaline 1 : 2,00,000 absorption in Small myelinated fibres ↓systemic absorption ; intercostal Addition of NaHCO3 (↑non ion- ↑duration & toxic dose. nerve block. ised form). Narcotics. Dose Toxicity Lignocaine : 3-5 mg/kg. Circumoral tinnitus (1st sign of CNS toxicity). Lignocaine + adrenaline : 7 GTCS (mainly lignocaine) : Rx with short mg/kg. acting BZDs. Bupivicaine & ropivicaine : Ventricular arrhythmias (CVS) : Mainly 2-3 mg/kg. Bupivacaine (R/x 20 % intralipid). Applications : Labour analgesia : a. 0.125 % bupivacaine (blockade of pain sensation only). b. 0.2 % ropivacaine. EMLA cream : Lignocaine + Prilocaine : Painless IV cannulation (surface anaesthesia). Biers block : a. IV regional anaesthesia (tourniquet + IV anesthaesia). b. Lignocaine 0.5 % or Prilocaine. c. Not recommended : Bupivacaine Anaesthesia Revision 1.0 Marrow 6.5 2023  18 03 Anaesthesia ----- Active space ----- Cocaine Sympathethic stimulation, severe vasoconstriction, mydriasis. Procaine Interacts with sulphonamides. Chlorprocaine Shortest acting LA (used in day care surgery). Prilocaine Toxicity : Methemoglobinemia Lignocaine 5% : Spinal anaesthesia 4% : Gargles. 2% : Jelly. 1-2 % : Nerve blocks. Ropivacaine Less cardiotoxic & motor blockade Inhalational anaesthetics 01:08:36 For induction & maintenance of anesthesia. Mayer overton rule : Lipid solubility ∝ potency. Potency : Minimum alveolar concentration (MAC) : Minimum amount of drug required to produce immobility to painful stimuli. MAC ∝ 1 potency Factors affecting uptake of agent : 1. From machine → alveoli Concentration effect : Inspired concentration ∝ quicker induction. Second gas effect (at start of surgery) : D/t rapid diffusion capcacity of N2O → Rapid onset of action of 2nd gas. Diffusion hypoxia/ Fink effect : Seen at end of surgery & opposite to sec- ond gas effect. Alveolar ventilation ∝ more uptake (quick induction). FRC : Smaller FRC is easier to induce. 2. From alveoli → pulmonary circulation Blood gas partition coefficient (B/G) = Concentration of agent in blood Concentration of agent in alveoli ↑B/G : More concentration in blood→more soluble →delayed induction ↓ B/G : Less concentration & solubility in blood → Quicker induction. BG : Desflurane < N2o < Sevoflurane < Isoflurane < Halothane < Methoxyflurane. MAC : N2o > Desflurane > Sevoflurane >Isoflurane > Halothane > Methoxyflurane. Anaesthesia Revision 1.0 Marrow 6.5 2023  Anaesthesia Revision 3 03 19 Systemic effects of inhalational agents : ----- Active space ----- System Halothane Isoflurane Desflurane Sevoflurane Pulmonary Sweet (2nd preferred) Pungent. Irritant. Sweet system :↓ RR. Good bronchodilator. Avoid in Avoid in (1st choice in asthmatics. asthmatics. children). Asthmatics : 1st preferred. ↓ Pulmonary vascular resistance except N2O. ↓ Ciliary motility (except ether). CVS : ↓ HR, BP. Max ↓ HR, Good Irritant Good. Bradyarrhythmias. cardiostable, causes Cardiostable. Sensitises Coronary steal initial myocardium to phenomenon. tachycardia. adrenaline. CNS : ↑ Cere- Max ↑ CBF, ↑ICP. The rise in ICP is countered by hyperventilation bral blood flow C/I in neurosurgery (↓etCO2 = ↓ICP). → ↑ ICP. Used in neurosurgery. Enflurane causes seizures. GIT, liver and Max ↓ LBF. - Minimally - biliary tract : Metabolite metabolised. ↓ Liver blood causes halothane flow. hepatitis in old age, female, >40 yrs, mul- tiple exposure. Renal - Best agent Max fluoride system : (Desflurane > Isoflurane) ions. Fluride ions Sevoflurane (added to + Soda lime = make it non Compound A inflammable) (nephrotoxic in causes lower animals). nephrotoxicity. Max nephrotoxicity : Methoxyflurane. Uterus Good uterine relaxants (↑risk of PPH). N2O : Teratogenic. Muscular ↓ muscle relaxant usage. system Trilene : Good analgesic. Ocular ↓ IOP Metabolism Max - Minimal - Xenon N2O Ideal anaesthetic agents. Blue cylinder at 760 psi pressure But ostly Prolonged exposure : Interferes with Vit B12 metabolism caus- ing megaloblastic anemia, SACD of spinal cord. Avoided in pneumothorax, middle ear surgeries, ocular sur- geries. 50% O2+ 50% N2O (Entenox) : Labour analgesia Anaesthesia Revision 1.0 Marrow 6.5 2023  20 04 Anesthesia ----- Active space ----- ANESTHESIA REVISION 4 Regional anesthesia Central neuraxial blockade Peripheral neuraxial blockade Spinal Epidural Caudal Nerve blocks Spinal Anesthesia 00:01:02 Indications : Any surgery below the level of umbilicus. Absolute C/I : ↑ ICP. Severe hypovolemia. Coagulopathy. Severe MS/AS. Patient refusal. Allergy to drugs. Local site infection. Location : Adults : L3-L4. Children : L4-L5. Procedure : 3 Ps. 1. Preparation : Strict aseptic precaution. 2. Position of patient : Prone, left lateral (or) sitting. 3. Projection of needle (layers encountered) : Skin → Subcutaneous tissue → Supraspinous ligament → Interspinous ligament → Ligamentum flavum (toughest layer) → Dura mater → Arachnoid mater. Needles : Types Based on action on Dura Based on gauge size Dura Cutting : Dura Splitting : Eg. : Quincke, Babcock. Eg. : Whitacre, Sprotte. Technically easier. ↑ PDPH. Technically difficult. ↓ PDPH. Note : ↓ Gauge size → ↑ Bore size → ↑ PDPH (Post Dural Puncture Headache). Anaesthesia Revision 1.0 Marrow 6.5 2023  Anesthesia Revision 4 04 21 Post-Dural Puncture Headache (PDPH) : ----- Active space ----- Typically seen in women after LSCS. Presentation : Dura cutting (Quincke needle) Occipital and frontal region. 24-48h after surgery. Dull, boring type. Aggravated by change in posture. Dura splitting (Whiteacre needle) Relieved : Rest. Associated with nausea, vomiting, photophobia. Never associated with fever, neck rigidity. Timing of ambulation doesn’t affect PDPH. Treatment : Adequate bed rest + Plenty of oral fluids. Simple analgesics : Caffeine + paracetamol. Severe cases : Epidural blood patch. Gauges Factors affecting height/Level Of Anesthesia (LOA) : Drug factors : Baricity of drug = Density of drug Density of CSF Drug + Dextrose → Hyperbaric → ↓ LOA. Drug + Distilled water → Hypobaric → ↑ LOA. Patient factors : CSF volume ∝ 1. LOA Pregnancy : ↑ IAP → ↑ LOA → Dose of LA ↓ by 30-40%. Height ∝ 1. LOA Procedure factors : Position : Hyperbaric drug in head down position → ↑ LOA. Epidural injection immediately post-spinal → ↑ Pressure → ↑ LOA. Side effects : Spinal anesthesia → Sympathetic blockade. Anaesthesia Revision 1.0 Marrow 6.5 2023  22 04 Anesthesia ----- Active space ----- Side effects of spinal anesthesia 1. CVS 1. ↓ HR (Rx : Atropine). 2. ↓ BP : Prevention : Preloading IV fluids. Rx : Pregnant → Phenylephrine Non-pregnant → Ephedrine. 2. Respiratory 1. Low LOA : No effect. system 2. High LOA : Only ICM paralysed (c/o shortness of breath). 3. GIT Sphincters relaxed. 4. GUT Urinary retention (M/C). Epidural Anesthesia 00:16:11 Identification of epidural space : Loss of resistance technique. Epidural catheter set with Tuohy needle Advantages Disadvantages 1. Prolong duration of anesthesia. 1. Technically difficult → Sometimes patchy block. 2. No chance of PDPH. 2. Delayed onset → Not suitable for emergencies. 3. LOA can be altered. 3. Catheter migration. 4. Stable hemodynamics. 4. Severe PDPH : If catheter pierces dura High spinal Total spinal LA toxicity C/o Shortness Enters arachnoid space Enters blood vessel. of breath → Unresponsive patient Lignocaine : Seizures. Bupivacaine : Arrhythmia. Caudal Anesthesia 00:22:22 Only in children. Location : S4-S5. Advantage : No chance of neurological injury. Disadvantage : Always accompanied by GA. Strict aseptic precautions to be taken. Anaesthesia Revision 1.0 Marrow 6.5 2023  Anesthesia Revision 4 04 23 Peripheral Nerve Block 00:24:15 ----- Active space ----- Brachial plexus block : Can be done at 4 levels. 1. Inter-scalene approach : Shoulder and 2. Supra-clavicular approach : upper arm surgeries. Used for fracture of : SA : Scalenus Anterior. Lower humerus. SM : Scalenus Medius. Radius and ulna. 3. Axillary approach : 4. Infra-clavicular approach : Blocks : Radial, ulnar & median nerves. Used for Radial, ulnar & Used for : Forearm surgeries. Musculocutaneous nerve Disadvantage : Doesn’t block blockade. musculocutaneous nerve. Given under USG guidance. Blocks at elbow : Radial nerve block Median nerve block Ulnar nerve block a : Finger palpating lateral a : Median nerve. humeral condyle. b : Biceps tendon. b : Biceps tendon. c : Brachial artery Anaesthesia Revision 1.0 Marrow 6.5 2023  24 04 Anesthesia ----- Active space ----- Blocks at wrist : Ulnar nerve Radial nerve Median nerve Blocks of the face : Supraorbital Infraorbital Anterior ethmoidal Mental Ankle block : Anaesthesia Revision 1.0 Marrow 6.5 2023  Anesthesia Revision 4 04 25 ----- Active space ----- Anesthesia machine 00:31:40 Boyle’s machine Anesthesia workstation Zones : 3 zones : 1. High pressure : Consists of gas cylinders. 2. Intermediate pressure. 3. Low pressure. Gas cylinders : Classification : Non-liquifiable. Eg. : O2 (2000 psi). Liquifiable. Eg. : N2O (760 psi). Identification : Gas Cylinder O2 Black body with white shoulder. CO2 Grey. N2O Blue. He Brown. N2 Black. Air White body with black shoulder. Cyclopropane Orange. Entonox Blue body with white shoulder. Entonox : 50% O2 + 50% N2O. Make of cylinders : Molybdenum steel alloy. Cylinders made of aluminium used in MRI rooms. Anaesthesia Revision 1.0 Marrow 6.5 2023  26 04 Anesthesia ----- Active space ----- Measurement of contents : Bourdon’s pressure gauge : Not required for N2O cylinder. Safety feature : 1. Pin Index Safety Feature (PISS). 2. Bodock’s pressure seal. PISS : Prevents wrong connection beyween cylinder & machine. Gas PISS O2 2, 5 N2O 3, 5 Air 1, 5 CO2 7.5% 1, 6 Entonox 7 Cyclopropane 3, 6 Bodock’s pressure seal : Also called gasket/washer. Prevents leakage of gases. One pressure seal should be present. Note : 1 mL of liquid O2 = 840 mL of gas O2. Anaesthesia Revision 1.0 Marrow 6.5 2023  Anesthesia Revision 4 04 27 O2 concentrator : ----- Active space ----- Principle : Pressure swing adsorbent technology. Provides 90-95% pure O2. Intermediate pressure zone : Components : Pipelines, O2 flush. Pipelines : Unique feature : O2 fail safe valve. O2 flush : Denoted by O2+. Temporarily hyperinflates lungs. Low pressure zone : Components : Flowmeters (aka rotameters). Location of O2 flowmeter : Downstream. Back bar Flowmeters Vaporiser installed on back bar → Vapourised liquid anesthetic → Patient Anaesthesia Revision 1.0 Marrow 6.5 2023  28 04 Anesthesia ----- Active space ----- Breathing circuits : Mapleson circuit Other name Use Mapleson A circuit Lack circuit Spontaneous respiration. Mapleson D circuit Bain circuit Controlled ventilation Mapleson F circuit Jackson Rees circuit Used in children. Mapleson circuits Soda lime/closed circuit : aka circle system. Key component : Soda lime. Mechanism : CO2 is reabsorbed and gases are recirculated. Anaesthesia Revision 1.0 Marrow 6.5 2023  Anaesthesia Revision 5 05 29 ANAESTHESIA REVISION 5 ----- Active space ----- Critical Care 00:00:36 Care of patient on vventilator. Ventilator modes Pressure control : VT , FiO2 , RR, I : E is provided. Pressure is fixed. Tidal volume is monitored. Volume control : VT is fixed. Pressure/airway resistance is monitored. PEEP (Positive End Expiratory Pressure) : Invasive FiO2 , BP. CPAP (Continuous Positive Airway Pressure) : Non invasive. In the table above, VT-Tidal volume , RR - Respiratory Rate, I:E - Inspiratory : Expiratory ratio. Applied aspect : Acute pancreatitis → ARDS like presentation → If PaO2 is normal, FiO2 is re- duced to avoid O2 toxicity. COPD → RR : Increased & PEEP : Minimal to eliminate excess CO2. Oxygen Therapy 00:10:25 Indications of oxygen therapy : Acute hypoxemia (PaO2 < 60 mm Hg; SpO2 < 98 %). Cardiac/Respiratory arrest. Hypotension (systolic BP < 100 mm Hg). Low cardiac output + metabolic acidosis (HCO-3 < 18 mmol/L). Respiratory distress (RR > 24/min) Oxygen Delivering devices : 1. Low flow variable performance devices : Nasal prongs Simple O2 mask Non Re-Breather mask/ O2 mask with reservoir bag Flow rate 1-6 litres/min 6-10 litres/min 10-15 Litres/min Max FiO2 44% 60-65 % 90-95 % Anaesthesia Revision 1.0 Marrow 6.5 2023  30 05 Anaesthesia ----- Active space ----- 2. High flow fixed performance devices : Venturi Mask : Used in COPD. Fixed O2 concentration. High Flow Nasal Cannula (HFNC) : Used in COVID. Flow rate : 40-80 Litres/min. Venturi mask High flow nasal cannula Basic and Advanced Life Support 00:13:12 Adult BLS Algorithm : Anaesthesia Revision 1.0 Marrow 6.5 2023  Anaesthesia Revision 5 05 31 Adult Cardiac Arrest Algorithm : ----- Active space ----- Anaesthesia Revision 1.0 Marrow 6.5 2023  32 05 Anaesthesia ----- Active space ----- High Quality CPR : Push hard at least 2 inches (5 cm) and fast (100-120/min) and allow complete chest recoil. Minimize interruptions in compressions. Avoid excessive ventilation. Change compressor every 2 minutes, or sooner if fatigued. If no advanced airway, 30 : 2 compression-ventilation ratio. Quantitative waveform capnography : If PETCO2 is low or decreasing reassess CPR Quality. Shock energy for defibrillation : Biphasic : 120-200J Monophasic : 360 J Drug therapy : Epinephrine IV/10 dose : 1 mg every 3-5 minutes Amiodarone IV/10 doses : First dose : 300 mg bolus. Second dose : 150 mg or Lidocaine IV/IO (First dose : 1-1.5 mg). Advanced airway : Endotracheal intubation or supraglottic advanced airway. Waveform capnography /capnometry to confirm & monitor ET tube placement. Once an advanced airway is in place, Give 1 breath every 6 seconds (10 breaths/min) with continuous chest compressions. Return of Spontaneous Circulation (ROSC) : Monitor pulse & blood pressure. Abrupt sustained increase in PETCO2 (typically 40 mm Hg). Spontaneous arterial pressure waves with intra-arterial monitoring. Reversible causes : (5H & 5T) Hypovolemia Tension pneumothorax Hypoxia Cardiac Tamponade Hydrogen ion (acidosis) Toxins Hypo/hyperkalemia Thrombosis (Pulmonary) Hypothermia Thrombosis (Coronoary) Anaesthesia Revision 1.0 Marrow 6.5 2023  Anaesthesia Revision 5 05 33 Adult tachycardia with a pulse algorithm 00:17:02 ----- Active space ----- Assess responsiveness, HR ≥ 150 Note : Tachycardia : HR ≥ 100 bpm. maintained Airway, Breathing, Circulation. Tachyarrhythmia : HR ≥ 150 bpm. Connect ECG, and IV access. 5 features of hemodynamic instability : Identify and treat underlying cause BP. Shock. Persistent Tachyarrhythmia Altered mental status. Ischemic discomfort. Acute heart failure. Assess hemodynamic stability Unstable Stable Synchronised Cardioversion/ DC shock. Check if wide QRS complex Consider Adenosine if narrow QRS Complex. Yes No Antiarrhythmic infusion. 1. Vagal maneuvers. Consider Adenosine only if 2. Adenosine. regular and monomorphic. 3. β blockers/ Ca2+ channel blockers. Antiarrhythmic infusion : 1. Procainamide : 20-50 mg/min until arrhythmia is suppressed. maximum dose : 17 mg/kg. Maintenance infusion : 1-4 mg/min. Avoid if prolonged QT or CHF. 2. Amiodarone : First dose : 150 mg over 10 mins. Repeat if VT recurs. Maintenance : Infusion of 1 mg/min for first 6 hrs. 3. Sotalol : 100 mg (1.5 mg/kg) over 5 minutes. Avoid if prolonged QT. Adult bradycardia algorithm 00:18:40 Bradycardia Note : Bradycardia : HR < 60 bpm. Hemodynamically Hemodynamically Bradyarrhythmia : HR < 50 bpm. stable unstable Monitor & Atropine IV 1 mg bolus. observe Repeat every 3-5 mins. Maximum dose : 3 mg Not effective Transcutaneous pacing/ Dopamine infusion Anaesthesia Revision 1.0 Marrow 6.5 2023