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Overview Of RSI, DSI & Airway Pharmacology

Sellick’s Maneuver: Cricoid Pressure

Sellick’s Maneuver Aspiration

•Gastric pH of less than 2.5•Volumes of greater than 0.4 mL/kg•Associated with alveolar/capillary

damage•Atelectasis, inflammatory response, loss

of surfactant, hypoxia, shunting, increased airway resistance and physical blockage of airways by food particulate

üPREPARATIONüIV ACCESSüS.A.D.üEQUIPMENT CHECKEDüMONITORS PLACED

üPREOXYGENATIONüINDUCTION – PARALYSIS –

SELLICK’S MANEUVERüDL – TIüCONFIRM TI AND MTP OF ETTüRELEASE CPüSECURE ETTüFREQUENT ASSESSMENT OF BP

STEPS FOR SUCCESS IN RSII Immediate Postintubation Period

• Confirm ETT placement• Assess ETT Depth• Secure the ETT• Initiate Positive Pressure Ventilation – avoid

hyperventilation• Blood Pressure Check• Treatment of Postintubation Hypotension• Treatment of Postintubation Hypertension

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Cardiovascular CNS Effects of Anesthetic Induction Agents

AGENT BP C.C CBF CMRO2 ICP CPP

STP � � � � � �ETOMIDATE

SL �

NC � � � �

PROP � � � � � �MDZ SL

�NC � � � NC

KET � �* � � � �

INDUCTION AGENTS: DOSAGE

AGENT STANDARDDOSE

TRAUMADOSE

THIOPENTAL 3-5 0.5-2

ETOMIDATE 0.2-0.3 0.1-0.2

PROPOFOL 1.5-2.5 0.5-1

MIDAZOLAM 0.1-0.2 0.05-0.1

KETAMINE 1-2 0.5-1

Rescue Drugs: Ephedrine

Indirect Vasopressor(mix 50mg/10 cc) 5 mg to 10 mg dosed incrementally to maintain SBP ≥ 100 mmHg

* works indirectly by releasing endogenous norepinephrine which increases inotrophy – caution with cardiac patients

Rescue Drugs: PhenylephrineDirect Vasopressor– 100 mcg/mL – direct vasoconstrictor –causes reflex bradycardia

Titrate with slow infusion or give 0.5 cc to 1 cc incrementally. Preparation: 10 mg in 100 ml of NS = 100 mcg/mL solution (0.1 mg / mL)

Rescue Drugs

Ephedrine (50mg/10 cc) 5 mg to 10 mg dosed incrementally to maintain SBP ≥ 100 mmHg

* works indirectly by releasing endogenous norepinephrine which increases inotrophy – caution with cardiac patientsPhenylephrine – 100 mcg/mL – direct vasoconstrictor – causes reflex bradycardia

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Neuromuscular Blockers

� Depolarizing Muscle Relaxants –Succinylcholine

� Nondepolarizing Muscle Relaxants1. Rocuronium2. Vecuronium

Muscle Relaxants: Dose, Onset Time & Duration

AGENT INTUB.DOSE

INTUBTIME(MIN)

DURATION(MIN)

SUX 0.6-1.1 1 4-6

ROC 0.6-1.2 0.7-1.1 31-67

VEC 0.08-0.10 2.5-3 25-40

REVERSAL OF NEUROMUSCULAR

BLOCKERSTO AVOID NEOSTIGMINE INDUCED ASYSTOLE

FIRST DRAW UP ROBINOL OR ATROPINE IN THE SYRINGE.THEN DRAW UP NEOSTIGMINE

SUGAMADEX

• INDICATIONS• MECHANISM OF ACTION• DOSAGE• DURATION• SIDE EFFECTS

RSI: Side Effects of Succinylcholine•Massive hyperkalemia in susceptible patients• Cardiac Arrhythmias: Bradycardia in Peds•Muscle fasiculations•Myalgias• Rhabdomyloysis• Increase ICP. IGP, IOC•MH•Master spasm• Prolonged apnea (atypical plasma cholinesterase)• Bradycardia in children < 2 Y.O. (pretreat with

I.M. atropine 10 mcg/kg

POSSIBLE ADVERSE EFFECTS OF SUCCIYLCHOLINE

• Exaggerated hyperkalemia in susceptible patients• Crush Injuries• Denervations• Prolonged Immobilization• Paraplegia• Hemiplegia• Disuse Atrophy• Severe Abdominal Infection• Muscular Dystrophy

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RSI & Succinylcholine – Is It Safe?

•Prolifereation of extrajunctionalacetylcholine receptors reqjuires 24 to 48 hours after denervation injury or burn.•Thus, succinylcholine-induced hyperkalemia is unlikely to occur in the acute setting.

Delayed Sequence Intubation• OVERVIEW• Delayed sequence intubation = DSI• DSI is procedural sedation, where the procedure is

preoxygenation• DSI may be useful in the patient who does not tolerate

preoxygenation by other means

Delayed Sequence Intubation• Overview• Ketamine is the ideal induction agent as it preserves

airway reflexes and respiratory drive• Rocuronium at 1.2 mg/kg is the ideal neuromuscular

blocker as it achieves rapid paralysis and the absence of defasciculation decreases oxygen consumption

Delayed Sequence Intubation• INDICATIONS• Patient who is agitated or is otherwise intolerant of

preoxygenation via nasal prongs, non-rebreather mask, bag-valve-mask, and/or non-invasive ventilation• Another procedure is required before intubation, but the

patient will not tolerate it (e.g. nasogastric tube placement prior to intubation in the setting of GI hemorrhage)

Delayed Sequence Intubation• PROCEDURE• identify agitated patient requiring intubation (see

indications)• administer induction agent, ideally ketamine 1-2 mg/kg• place non-rebreather mask and nasal cannula at 15

L/min each

Delayed Sequence Intubation• Procedure Continued• if SpO2 is <95% then use CPAP or BMV with PEEP valve

at 5-15 cmH20 (this usually takes 2-3 minutes, but may take up to 10 minutes – if oxygenation does not improve during this time then it may be necessary to proceed with intubation with SpO2 <95%)

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Delayed Sequence Intubation• Procedure Continued• administer neuromuscular blocker and wait 45-60

seconds• perform apneic oxygenation using 15 L/min O2 via nasal

prongs +/- continue CPAP• intubate patient

Delayed Sequence Intubation`

• EVIDENCE

• Weingart et al, 2014

• prospective observational study

• convenience sample of 64 patients (two lost to analysis)

• patients were those requiring emergency intubation who did not tolerate pre-

oxygenation with traditional methods, and were not predicted to have a difficult

airway

• there were no complications – two well oxygenated patients had minor reductions in

their oxygen saturations but they did not receive nasal cannulae for pre/apneic

oxygenation

• DSI was performed using ketamine resulting in significantly improved oxygen

saturations prior to intubation: 88.9% vs 98.8% (increase of 8.9%, 95% C.I. 6.4-10.9)

• two patients with asthma improved sufficiently to avoid intubation all together

Apneic Oxygenation• Apneic oxygenation: Everything you know is wrong• Take your time to get that tube smoothly, non-traumatically into trachea on

1st pass• My instructors paraphrased it in more practical terms, admonishing us to hold

our breaths when we began an intubation attempt. "When you need to take a breath, so does the patient," they reminded us.

• The concept was reinforced during countless NREMT skill stations, where we routinely failed candidates for taking longer than 30 seconds on a single intubation attempt. Those poor candidates trudged the walk of shame back to the routing area to take their places beside the other failed candidates who committed the unpardonable sin of forgetting to say, "I'll have my professional partner hyperventilate the patient while I prepare my equipment."

Apneic Oxygenaiton• I was also taught that a nasal cannula can only deliver a maximum of 44

percent oxygen and that non-rebreather masks can provide more than 95 percent oxygen.

• Turns out, none of the above was true.

Apneic Oxygenation