Lesson
Use Stress-Ulcer Prophylaxis Only While Risk Persists
Stress-related mucosal bleeding prevention is a temporary risk intervention. Coagulopathy, shock, and chronic liver disease are the clearest current risk factors, while enteral nutrition changes the balance and mechanical ventilation alone is no longer a sufficient shortcut.
- Risk stratification
- PPI
- H2RA
- Enteral nutrition
- Deprescribing
Coagulopathy, shock, and chronic liver disease carry the clearest current signal.
Use a low-dose enteral or intravenous option when risk justifies exposure.
Discontinue when risk resolves and avoid an unnecessary discharge medicine.
Separate ICU location from bleeding risk
The 2024 SCCM and ASHP guideline identifies coagulopathy, shock, and chronic liver disease as likely risk factors for clinically important stress-related upper gastrointestinal bleeding. Evidence was insufficient to preserve mechanical ventilation as an independent automatic trigger. Reassess physiology and risk instead of copying a historical checklist.
Choose a low-dose preventive regimen
For adults who remain at risk, either a proton pump inhibitor or histamine-2 receptor antagonist is reasonable. Enteral and intravenous routes are both acceptable when clinically feasible. Drug interactions, kidney function, enteral access, prior acid disease, and local protocol should determine the exact regimen.
Stop when the reason ends
Enteral nutrition probably reduces bleeding risk, and low-risk patients receiving enteral nutrition should not receive routine prophylaxis. Review the indication daily, discontinue when the risk factor resolves, and avoid carrying prophylaxis through ICU transfer or discharge unless a separate indication remains.
Quick check
Lesson
Map Local Anesthetic Effect and Disposition
Local anesthetics must cross tissue and membrane, enter the axon, and bind voltage-gated sodium channels from the intracellular side. Molecular state, tissue pH, lipid solubility, protein binding, blood flow, dose, and metabolism shape onset, potency, duration, and toxicity.
- Sodium channels
- Ionization
- Amides
- Esters
- Additive toxicity
Uncharged drug moves through tissue and axonal membrane.
Protonated drug reaches the intracellular sodium-channel site.
Dose, blood flow, organ function, and every local anesthetic shape systemic risk.
Connect pH to access and block
The uncharged fraction crosses lipid membrane, while the protonated form binds within the sodium channel. Inflamed acidic tissue shifts drug toward ionization before membrane entry and can slow or weaken block. Use-dependent binding favors channels that open repeatedly, which explains selective suppression of rapidly firing fibers.
Distinguish disposition families
Amide agents such as lidocaine, bupivacaine, and ropivacaine are metabolized mainly in the liver. Ester agents are hydrolyzed largely by plasma cholinesterases and can generate para-aminobenzoic-acid-related metabolites. Patient physiology, not the suffix alone, determines the complete safety plan.
Treat all exposure as one toxicity budget
Local-anesthetic systemic toxicity is additive across products. Use the lowest effective dose, aspirate where appropriate, administer fractionally when feasible, monitor consciousness, ventilation, rhythm, and circulation, and maintain immediate access to oxygen, resuscitation equipment, skilled personnel, and a LAST kit.
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Lesson
Treat Local Anesthetic Systemic Toxicity as a Distinct Arrest Pathway
LAST can begin with perioral symptoms, tinnitus, altered speech, agitation, or seizure, but severe cardiovascular toxicity can appear abruptly. The rescue sequence differs from standard ACLS because several familiar resuscitation drugs can worsen local-anesthetic cardiotoxicity.
- Recognition
- Airway
- Lipid emulsion
- Modified ACLS
- Observation
Prevent hypoxemia, hypercapnia, and acidosis while controlling seizure.
Use the current ASRA weight-based bolus and infusion pathway.
Use smaller epinephrine and avoid vasopressin and other aggravating drugs.
Stop exposure and stabilize physiology
Stop injection, call for help, secure oxygenation and ventilation, and prevent acidosis, hypoxemia, and hypercapnia that can intensify toxicity. Prefer a benzodiazepine for seizure when available. Do not wait for a complete textbook progression before activating the rescue pathway.
Give 20 percent lipid emulsion early
For patients under 70 kg, the ASRA checklist uses an approximately 1.5 mL/kg bolus over 2 to 3 minutes followed by about 0.25 mL/kg/min. For patients over 70 kg, it provides approximately 100 mL as a bolus followed by about 250 mL over 15 to 20 minutes. Rebolus or increase infusion for instability while respecting the checklist maximum of 12 mL/kg.
Modify the resuscitation medicines
When epinephrine is needed, use smaller doses at or below 1 microgram/kg. Avoid vasopressin, beta blockers, calcium-channel blockers, additional local anesthetic, and other listed aggravating agents. Continue observation after stability because recurrence can occur, and obtain expert or bypass support when the course is refractory.
Quick check
Lesson
Choose Induction Through Physiology
Propofol, etomidate, and ketamine can all produce hypnosis, but their cardiovascular, respiratory, endocrine, analgesic, and recovery effects are different. The correct choice begins with the patient's current physiologic constraint and the airway plan.
- Propofol
- Etomidate
- Ketamine
- Hemodynamics
- Airway
Fast hypnosis and recovery can cost pressure and ventilation.
Relative hemodynamic stability trades against myoclonus and adrenal suppression.
Often stimulating, but not immune to apnea, emergence, or catecholamine-depleted collapse.
Use propofol when rapid control fits the reserve
Propofol provides rapid hypnosis and titratable recovery but can cause apnea, vasodilation, myocardial depression, and severe hypotension. Reduce and titrate exposure in older, debilitated, hypovolemic, or unstable patients and ensure immediate ventilatory and circulatory support.
Use etomidate with endocrine honesty
Etomidate often preserves pressure better during induction but commonly causes injection pain and myoclonus. A single induction dose can reduce cortisol and aldosterone concentrations through adrenal steroid-synthesis inhibition. The clinical tradeoff is limited immediate cardiovascular depression versus a measurable endocrine effect.
Use ketamine without calling it fail-safe
Ketamine adds analgesia and often increases pressure and pulse. Emergence reactions, hypersalivation, airway obstruction, laryngospasm, and respiratory depression after rapid high dosing remain possible. Catecholamine-depleted patients can develop falling pressure or cardiac decompensation, and coadministration with other CNS depressants increases respiratory risk.
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Lesson
Recognize and Interrupt Malignant Hyperthermia
Malignant hyperthermia is uncontrolled skeletal-muscle calcium release in susceptible patients after volatile anesthetics, succinylcholine, or both. Rising carbon dioxide and rigidity can precede dramatic temperature elevation, so treatment begins from the pattern rather than a late threshold.
- Triggers
- Hypercapnia
- Dantrolene
- Cooling
- Recurrence
Early hypercapnia, tachycardia, acidosis, and muscle rigidity define the pattern.
Stop volatile agents and succinylcholine, then give repeated actual-weight dantrolene.
Cool, correct potassium and acidosis, protect kidneys, and monitor recurrence.
Recognize the hypermetabolic pattern
Unexpected rapid carbon-dioxide rise despite ventilation, tachycardia, masseter or generalized rigidity, mixed acidosis, hyperkalemia, rhabdomyolysis, and increasing temperature should activate the crisis response. Stop volatile agents and succinylcholine immediately and call for help and the malignant-hyperthermia cart.
Give dantrolene and oxygen without delay
Hyperventilate with 100 percent oxygen at high flow, remove or disable volatile delivery, use activated charcoal filters when available, and give dantrolene 2.5 mg/kg intravenously using actual body weight. Repeat rapidly until carbon dioxide, rigidity, rate, temperature, and metabolic instability improve. Total dosing can exceed 10 mg/kg.
Correct complications and prevent recurrence
Cool actively when temperature is elevated, stop near 38 C to avoid overshoot, treat hyperkalemia and dysrhythmia, monitor gases, potassium, glucose, CK, urine, coagulation, kidney function, and core temperature. Continue MHAUS-directed dantrolene and intensive observation because recrudescence can occur after apparent control.
Quick check
Lesson
Understand Block Before Choosing a Drug
Neuromuscular blockers prevent skeletal-muscle contraction at nicotinic acetylcholine receptors. Succinylcholine depolarizes the end plate, while nondepolarizing agents competitively block receptor activation. Neither mechanism supplies pain relief, amnesia, or unconsciousness.
- Motor end plate
- Depolarizing block
- Competitive block
- No sedation
- Recovery
Persistent end-plate activation produces phase I paralysis.
Receptor antagonism prevents acetylcholine from generating contraction.
Sedation, analgesia, ventilation, and monitoring remain separate requirements.
Read the neuromuscular junction
Motor neurons release acetylcholine, which binds postsynaptic nicotinic receptors and opens cation channels. A sufficient end-plate potential activates nearby voltage-gated sodium channels and produces muscle contraction. Acetylcholinesterase rapidly terminates the signal.
Separate depolarizing from competitive block
Succinylcholine initially activates the receptor and produces fasciculation, then persistent depolarization prevents repeated contraction during phase I block. Rocuronium, vecuronium, cisatracurium, and related agents compete with acetylcholine without activating the receptor.
Keep consciousness visible when movement disappears
Paralysis removes movement and respiratory-muscle function but leaves the brain capable of pain, memory, fear, and awareness. Adequate sedation and analgesia must be established before paralysis and maintained independently throughout its effect.
Quick check
Lesson
Use Succinylcholine Only After a Risk Screen
Succinylcholine has rapid onset and a short usual duration, but its depolarizing mechanism creates distinctive hyperkalemia, bradycardia, malignant-hyperthermia, myalgia, pressure, pediatric, and prolonged-apnea hazards.
- Hyperkalemia
- Pediatric warning
- Bradycardia
- Malignant hyperthermia
- Pseudocholinesterase
Denervation, burns, immobility, myopathy, and injury can amplify potassium release.
The boxed warning limits routine pediatric convenience use.
Ventilate and maintain unconsciousness until objective recovery is complete.
Identify receptor-upregulation risk
After major burns, denervation, spinal-cord or peripheral-nerve injury, prolonged immobilization, stroke-related paralysis, or neuromuscular disease, extrajunctional receptors can produce dangerous potassium release. The risk evolves over time and cannot be reduced to one universal day count.
Respect the pediatric boxed warning
Hyperkalemic rhabdomyolysis, ventricular dysrhythmia, arrest, and death have occurred in children with unrecognized skeletal-muscle myopathy. Reserve pediatric succinylcholine for emergency airway control or situations where the airway must be secured immediately.
Support prolonged block rather than guessing
Plasma-cholinesterase deficiency, pregnancy, liver disease, malnutrition, organophosphates, and selected medicines can prolong block. Continue controlled ventilation and adequate unconsciousness until quantitative recovery. Phase I block is not treated like shallow nondepolarizing block, and reflexive neostigmine can prolong it.
Quick check
Lesson
Select Nondepolarizing Block With Recovery in Mind
The useful onset of rocuronium, the aminosteroid disposition of rocuronium and vecuronium, and the organ-independent Hofmann elimination of cisatracurium create different tradeoffs. Volatile anesthetics, magnesium, antibiotics, temperature, acid-base state, and cumulative dose can all change duration.
- Rocuronium
- Vecuronium
- Cisatracurium
- Hofmann elimination
- Interactions
Rapid intubation is followed by variable hepatobiliary and renal recovery.
Organ dysfunction and active metabolite can extend block.
Organ-independent degradation is useful, but pH, temperature, and monitoring still matter.
Use rocuronium for rapid onset with a complete exit plan
Rocuronium is labeled for rapid-sequence and routine intubation plus skeletal-muscle relaxation during surgery or mechanical ventilation. Its duration varies substantially and can be prolonged by organ dysfunction, volatile anesthetics, magnesium, aminoglycosides, and cumulative dosing.
Recognize aminosteroid disposition
Rocuronium is eliminated mainly through hepatobiliary pathways with some renal contribution. Vecuronium depends on hepatic metabolism and biliary and renal elimination, with an active metabolite that can accumulate. Kidney and liver dysfunction therefore alter the reliability of clock-based recovery.
Use cisatracurium when organ-independent elimination fits
Cisatracurium undergoes Hofmann degradation, reducing dependence on kidney and liver. Temperature and pH still influence degradation, and prolonged use still requires objective monitoring, full sedation, ventilation, and daily indication review.
Quick check
Lesson
Make Paralysis a High-Reliability System
A wrong-vial event can cause silent respiratory arrest, and intended paralysis can hide awareness, pain, seizures, pressure injury, and ventilatory failure. Safe use depends on storage engineering and a bedside care bundle, not on memory alone.
- Segregation
- Paralyzing-agent warning
- Ventilation
- Sedation
- Supportive care
Restrict access and use unmistakable paralyzing-agent warnings.
Confirm mechanical support, analgesia, sedation, and indication before dosing.
Maintain eye, skin, thrombosis, positioning, temperature, and daily stop safeguards.
Prevent accidental selection
ISMP recommends segregating and sequestering neuromuscular blockers, limiting availability to high-acuity areas or protected rapid-sequence kits, using locked lidded compartments, and applying prominent warnings that identify a paralyzing agent and the need for ventilation.
Verify before and after administration
Use pharmacist-verified profiles when possible, barcode scanning, independent checks for indication and ventilation, labeled syringes, and immediate documentation. Never call these medicines muscle relaxants because the softened language conceals the respiratory-arrest consequence.
Protect the immobilized patient
Maintain mechanical ventilation, adequate analgesia and sedation, eye lubrication and closure, pressure and skin care, thrombosis prevention, positioning, temperature control, and repeated neuromuscular assessment. Review ongoing need and use the lowest effective exposure.
Quick check
Lesson
Measure Recovery and Match the Reversal
Clinical signs and subjective twitch counts miss residual paralysis. Quantitative adductor-pollicis monitoring establishes block depth, selects the reversal approach, and confirms a train-of-four ratio of at least 0.9 before extubation.
- Quantitative TOF
- Sugammadex
- Neostigmine
- Antimuscarinic
- Extubation
Use adductor-pollicis monitoring rather than strength tests or elapsed time.
Match sugammadex or neostigmine to the blocker and objective depth.
Do not extubate until quantitative recovery and airway readiness are established.
Use objective recovery
The ASA recommends quantitative rather than clinical or qualitative assessment when neuromuscular blockers are used. Monitor at the adductor pollicis and confirm a train-of-four ratio at or above 0.9 before extubation. Head lift, grip, and tidal volume do not reliably exclude residual weakness.
Dose sugammadex from measured depth
Sugammadex reverses rocuronium and vecuronium. Current labeling uses actual body weight: 2 mg/kg at reappearance of T2, 4 mg/kg with 1 to 2 post-tetanic counts and no train-of-four twitch, and 16 mg/kg for the labeled immediate-reversal scenario about 3 minutes after 1.2 mg/kg rocuronium. It is not recommended in severe renal impairment and does not reverse succinylcholine or cisatracurium.
Use neostigmine after spontaneous recovery
Neostigmine is suited to shallow nondepolarizing block after meaningful spontaneous recovery. Pair 0.03 to 0.07 mg/kg with atropine or glycopyrrolate, do not exceed 0.07 mg/kg or 5 mg, and continue objective airway and neuromuscular monitoring. Excess dosing during profound block does not create reliable recovery.
Quick check
Lesson
Use Antifibrinolytics With Route and Renal Discipline
Tranexamic acid and aminocaproic acid are lysine analogs that reduce fibrinolysis. Their value depends on a bleeding context in which fibrinolysis matters, while kidney clearance, thrombosis, seizure risk, and route errors define the safety boundary.
- Tranexamic acid
- Aminocaproic acid
- Plasminogen
- Renal function
- Route safety
Use the medicine only when clot breakdown is part of the problem.
Keep tranexamic acid physically and visually separated from neuraxial drugs.
Renal elimination makes dose and toxicity surveillance patient specific.
Block fibrinolysis deliberately
Both agents compete at lysine-binding sites involved in plasminogen and plasmin interaction with fibrin. This stabilizes formed clot but does not replace source control, fibrinogen, platelets, coagulation factors, temperature correction, or treatment of the actual bleeding mechanism.
Make tranexamic-acid route unmistakable
The FDA injection indication is narrow, while many trauma, surgical, and obstetric uses rely on other evidence and protocols. Adjust for renal impairment. Clearly label the intravenous route and segregate from neuraxial medicines because accidental intrathecal or epidural administration has caused seizures, dysrhythmia, permanent injury, and death.
Use aminocaproic acid only for fibrinolytic bleeding
Aminocaproic acid is primarily renally eliminated, and clearance approximates endogenous creatinine clearance. Confirm that fibrinolysis contributes to bleeding, avoid creating upper-urinary-tract obstruction from stabilized clot, and reassess exposure in severe renal failure.
Quick check
Module test
Check the connections.
Each attempt draws 10 questions from the complete 112 question bank.
Each attempt draws a fresh set and rearranges the answer choices.
References
Current clinical foundation.
Lecture material was synthesized with the following contemporary guidance. Verify local policy and current guidance before applying clinical information.
- SCCM and ASHP: Prevention of Stress-Related Upper Gastrointestinal Bleeding in Critically Ill Adults
- ASRA: Checklist for Treatment of Local Anesthetic Systemic Toxicity
- MHAUS: Managing a Malignant Hyperthermia Crisis
- ASA: Practice Guidelines for Monitoring and Antagonism of Neuromuscular Blockade
- ISMP: Targeted Medication Safety Best Practices for Hospitals
- DailyMed: Bupivacaine Hydrochloride Injection
- DailyMed: Succinylcholine Chloride Injection
- DailyMed: Rocuronium Bromide Injection
- DailyMed: BRIDION
- DailyMed: Neostigmine Methylsulfate Injection
- DailyMed: Ketamine Hydrochloride Injection
- DailyMed: Tranexamic Acid Injection
- DailyMed: Aminocaproic Acid Injection