Emergencies Flashcards

1
Q

Airway Fire

Management
Prevention

A

Airway Fire

Management

Inform team & call for help

Simultaneously remove the endotracheal tube (ETT) & stop gases/disconnect circuit

Pour saline or water into airway

Remove airway foreign bodies (ie: ETT pieces, sponges)

When fire is extinguished: re-establish ventilation; avoid supplemental oxygen if possible

Consider prompt reintubation prior to swelling & coordinated with bronchoscopy

Examine entire airway (including bronchoscopy) to assess injury & remove residual debris

Prevention

For high risk procedures:

Discuss fire prevention & management with team during time-out

Avoid FiO2 > 0.3 & avoid N2O

For laser surgery of vocal cord or larynx:

Use laser resistant ETT (single or double cuff)

Assure ETT cuff sufficiently deep below vocal cords

Fill proximal ETT cuff with methylene blue-tinted saline (acts as a marker if cuff perforated by laser)

Ensure laser in STANDBY when not in active use

Surgeon protects ETT cuff with wet gauze

Surgeon confirms FiO2 < 0.3 & no N2O prior to laser use (may require several minutes to dilute FiO2 & FeO2 to <0.3 depending on fresh gas flow & initial FiO2)

For non-laser surgery in oropharynx:

Regular PVC ETT may be used

Consider packing wet gauze around ETT to minimize O2 leakage

Consider continuous suctioning of the operating field inside oropharynx

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2
Q

Anaphylaxis

Signs
Management

A

Anaphylaxis

Signs

Rash/hives

Angioedema

Hypotension

Tachycardia

Hypoxemia

Bronchospasm/wheezing

↑ peak inspiratory pressure

Management

Stop offending agent

Inform surgeon, call for help

Discontinue or ↓ all anesthetic agents

Airway:

100% O2

Secure airway

Administer epinephrine IV in escalating doses:

Start at 10-100 mcg & ↑ as necessary until clinical improvement

Consider early epinephrine infusion (start at 2-20mcg/min)

Aggressive fluid resuscitation (may require several litres)

Bronchospasm: salbutamol PRN

Give secondary medications:

H1 antagonist: diphenhydramine 25-50mg IV

H2 antagonist: ranitidine 50mg IV

Methylprednisolone 1-2mg/kg IV per day OR dexamethasone 20mg IV

Start invasive lines: arterial line, central line

Refractory hypotension despite epinephrine:

Vasopressin 1-40 unit bolus, 0.01-0.04 units/min infusion

Glucagon 1-2 mg over 5 min IV then 5-15 mcg/min IV infusion (especially for patients taking beta blockers; inotropic & chronotropic effects not mediated through beta receptors)

Methylene blue 1-2mg/kg IV (inhibits nitric oxide synthase & guanylate cyclase)

Consider bicarbonate (0.5-1 mEq/kg) with acidosis

Consider transesophageal echocardiography (TEE) & entertain other differential diagnosis

Post-event care:

Laboratory tests to support diagnosis:

Serum tryptase levels 15 minutes and 3 hours after onset of symptoms

Serum histamine levels peak 5 - 15 minutes after onset of symptoms; return to baseline at 60 minutes

Discharge to ICU intubated & ventilated

Due to biphasic nature, monitor at least 24 hours

Consult allergist

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3
Q

Aspiration Event

Background
Considerations
Prevention
Management

A

Aspiration Event

Background

Definition: inhalation of gastric contents into the lung via passive regurgitation or active vomiting

Common patients:

“Full stomach”: Not NPO, bowel obstruction, pregnant, gastroparesis, intoxicated

Incompetent LES: hiatal hernia, previous esophageal/gastric surgery, obese

Can’t protect airway: ↓ LOC, residual NMB, neurologic disease

Considerations

Signs/symptoms: Severe hypoxemia, ↑ peak insp. pressure, bronchospasm, ↑ tracheal/oropharyngeal secretions, chest retractions, dyspnea, coughing, laryngospasm, pulmonary edema

↑ morbidity/mortality: pneumonia, ARDS, sepsis, barotrauma

CXR: infiltrates and atelectasis, but can be unremarkable

Prevention​

Avoid GA & excessive sedation if possible

Consider awake intubation

Ensure NPO status, if elective

Medications prior to induction:

Non-particulate antacide: Sodium citrate PO

H2 Antagonists: Ranitidine IV

Metoclopramide IV

Suction through NGT before inducing

Remove NGT when inducing

Suction on

Cricoid pressure

Management

Suction oropharynx

Intubate & inflate cuff

Suction through ETT

PPV with 100% and adequate PEEP

Bronchoscopy to:

Assess level of contamination

Remove particulate matter

Cancel elective surgery & minimize emergency surgery

Supportive care

Crystalloids better than colloid, H2 blockers, intermittent pulmonary toilet

Consider antibiotics

Consider ECMO if unable to oxygenate

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4
Q

Bronchospasm

Signs ​
DDx
Management

A

Bronchospasm

Signs ​

Wheezing on lung auscultation

Slow or incomplete expiration

Change in EtCO2:

​Upsloping waveform

Severe ↓ or absent waveform

↓ tidal volume

↓ oxygen saturation

↑ peak airway pressure

Differential Diagnosis

↑ resistance:

Bronchial asthma

COPD with reversible component

Laryngospasm (if supraglottic airway)

Anaphylaxis

↓ compliance:

Aspiration

Pulmonary edema

Pulmonary embolism/fat embolism/amniotic fluid embolism

Pneumothorax

Opioid-induced chest wall rigidity

Inadequate muscle relaxation

Circuit/machine problems

ETT/supraglottic airway:

Kinked

Malposition

Endobronchial/esophageal/submucosal

Herniated cuff

Foreign body/secretions

Management

Adjust FiO2 as necessary, remove irritants, deepen anesthesia

Disconnect & hand-ventilate to assess compliance, rule out other possibilities

Beta 2 agonists are first line treatment:

Salbutamol 4-8 puffs via ETT OR 2.5-5mg via nebulizer q20min PRN

Epinephrine infusion 0.5-2mcg/min in severe, refractory cases

Anticholinergics: ipratropium 4-8 puffs via ETT OR 0.5 mg via nebulizer q20min PRN

Steroids: methylprednisolone 125mg IV OR dexamethasone 8mg IV

Appropriate ventilation to avoid dynamic hyperinflation:

Longer expiratory time (I:E 1:3-1:5)

Low/normal respiratory rates (8-12/min)

Permissive hypercapnia

Adjuncts:

Bronchodilating anesthetics: volatiles > ketamine > propofol

Magnesium sulfate 2g IV over 20min

Heliox (does not reverse bronchospasm, but can be used as a temporizing measure)

Neuromuscular blocking drugs (may improve mechanics of ventilation & lower peak inspiratory pressures)

Extracorporeal membrane oxygenation (ECMO) if severe & refractory to all other treatments

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5
Q

Compartment Syndrome

Background​
Considerations

A

Compartment Syndrome

Background​

Fascial membranes in the human body combine to surround muscle groups in the human body

Compartment syndrome: increased pressure in fascial compartments compromises circulation and function of tissue within these compartments

Positive feedback: ischemia —> necrosis —> edema —> further increase in compartment pressure

Epidemiology:

Occurs most commonly after trauma, esp long bone #

Incidence 7.3/100k in men and 0.7/100k in women

Most common sites are the:

Fibular and extensor compartments in lower leg

Extensor compartment in forearm

Risk factors:

Sustained fracture or soft-tissue injury

Tibial diaphyseal, distal radius & diaphyseal forearm #’s

↑ Age

↑ Comminuted #

High-energy mechanism

Considerations

Have a ↑ degree of suspicion in at-risk patients

3 P’s (low sensitivity to & high specificity):

Pain - main clinical sign, classically pain “out of proportion” to injury

Paresthesia - late clinical sign

Paresis - even later clinical sign

Diagnosis:

Clinical signs/symptoms (3 P’s)

Measure compartment pressure, where normal compartment pressure ~ 8mmHg

Calculate Critical Δ Tissue pressure = Diastolic BP - compartment pressure

> 30mmHg = normal

< 30mmHg = indication for fasciotomy (100% sens & 100% specif)

Achieve adequate pain control with the lowest possible dose

In effort to avoid delayed diagnosis of compartment syndrome

Sudden increase in pain should be compartment syndrome until proven otherwise

Avoid epidurals in patients at ↑ risk

Theoretical, ↑ risk of delayed diagnosis of compartment syndrome

If using epidural, use low-concentration solution

Peripheral regional anesthesia is safe & does not delay diagnosis of compartment syndrome

But opt to use dilute concentrations & minimal adequate dose

Liberal indication for fasciotomy

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6
Q

Delayed Emergence

Differential Diagnosis (“DIMS”)
Management

A

Delayed Emergence

Differential Diagnosis (“DIMS”)

Drugs

Anesthesia related:

Sedatives & narcotics

Residual paralysis, pseudocholinesterase deficiency

Drug error

Non-anesthesia related:

Street drugs, alcohol

Herbal medicines (valerian root, St. John’s wort)

Infection:

Encephalitis, meningitis

Sepsis

Metabolic:

Hypoxia

Hypercarbia

Electrolyte abnormalities

Hypoglycemia or hyperglycemia (DKA or HONK)

Hypothermia

Uremia

Hepatic encephalopathy

Osmolality problems

Myxedema coma

Structural:

Stroke (ischemic or hemorrhagic)

Hydrocephalus

Diffuse anoxic injury

Cerebral edema

Seizure or post-ictal

Pneumocephalus

Cerebral hyperperfusion syndrome (post carotid endarterectomy)

Management

Scan monitors: HR, ECG, rhythm, EtCO2, SpO2, BP, temp

Ensure stability of ABC’s

Confirm reversal of paralysis

Review all drugs administered & syringes for drug error

Focused physical exam:

Neurological: GCS, pupils, gag/cough, symmetric motor movement, focal signs

Cardiorespiratory: adequacy of perfusion

Blood work:

CBC, lytes, urea, creatinine, glucometer, osmolality, ABG with lactate & ionized calcium

Liver enzymes, bilirubin

Toxicology screen

TSH, FT4

Consider: Neurology / ICU consultation, CT head, EEG, lumbar puncture

Empiric therapy:

Glucose: 25-50 cc of D50 or 250 cc of D10

Thiamine 100 mg IV

Opioid reversal: naloxone 0.04 mg IV q 2 mins, up to 2mg

Benzodiazepine reversal: flumazenil 0.2-1 mg IV q 1 min, up to 1mg

Physostigmine (0.5 to 1 mg IV) counteracts but does not reverse sedation caused by inhalation anesthetics, other sedatives, & anticholinergics

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7
Q

Dental Injury

Considerations
Management
Prevention

A

Dental Injury

Considerations

Upper central incisors are most frequently injured

Need to inform patient of risk of dental damage whenever manipulating airway

Can be caused by:

Intubation

LMA placement

Suctioning

Extubation

After extubation (i.e. biting down on OPA)

Risk factors:

Difficult intubation

Poor dentition

Previous dental work

Major morbidity if tooth fragments aspirated into airway

Management

Dislodged teeth should be put in saline

Ensure all tooth fragments are found and removed

Consult dentistry

Prevention

Careful technique

Choose VL over DL

Consider use of mouth guard during DL/VL

Use muscle relaxants

Use bite block

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7
Q

Extravasation Injuries

Management of Vasopressor Extravasation
Prevention

A

Extravasation Injuries

Management of Vasopressor Extravasation

Stop injection/infusion immediately; leave the catheter in place

Place immediate substitute IV access; resume vasopressors

Slowly aspirate as much of the drug as possible

Elevate the area & apply warm compresses for 48 hours

Consult plastic surgery & vascular surgery for opinion & ongoing management

Reversal:

First line: phentolamine subcutaneously

Dilute phentolamine 5 mg in 10 mL 0.9% sodium chloride

A dose of 0.1-0.2 mg/kg (up to a maximum of 10 mg) should then be injected through the catheter & subcutaneously around the site

Use 25 g or smaller needle

Additional injections may be required if blanching returns

Systemic hypotension may occur

Other options:

Topical nitroglycerin 2% 1-inch strip applied to the site of ischemia (redose q8h PRN)

Terbulatine subcutaneously 1mg in 10ml NS, inject locally across symptomatic sites

Consider sympathetic block, e.g. stellate ganglion (case reports of success)

Consider a saline-wash out method or liposuction:

​Saline wash out:

Probably the most effective way of removing drug from the site of extravasation & has been shown to reduce tissue injury

Under sterile conditions with local or general anaesthesia, four to six stab incisions are made around the area of extravasation

A blunt-ended cannula is inserted through one of the incisions & a large volume of saline flushed through the subcutanous tissues

The saline exits through the other incisions

Liposuction:

Blunt-ended liposuction cannula is inserted into the area of extravasation & used to aspirate fat & extravasated material

Less effective than saline washout

Prevention

Avoid IVs in the hand/wrist

Avoid unreassuring IVs

Perform protocolized extremity checks

Keep antidotes & worksheet in the room with the patient

10 mg of phentolamine mesylate can be added to each liter of solution containing norepinephrine (the vasopressor effect of norepinephrine is not affected)

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8
Q

Increased Airway Pressure

Differential diagnosis
Management

A

Increased Airway Pressure

Differential diagnosis

Circuit or machine problem:

Ventilator/bag switch in wrong position

Stuck valve (inspiratory/expiratory/APL)

Oxygen flush valve stuck in “on” position

Kinked/misconnected hose in circuit/scavenge limb

Failure of check valves/regulators in machine, allowing high-pressure gas into low-pressure circuit

PEEP valve accidentally placed in inspiratory limb

ETT/supraglottic airway problem:

Kinked tube

Malpositioned supraglottic airway

Endobronchial, esophageal, submucosal intubation

Herniated cuff obstructing end of tube

Dissection of interior surface of tube leading to airway narrowing

↓ pulmonary compliance:

↑ intra-abdominal pressure

Pulmonary aspiration

Bronchospasm

↓ chest wall compliance

Pulmonary edema

Pneumothorax

Drug-induced problem:

Opioid-induced chest wall rigidity

Inadequate muscle relaxation

Malignant hyperthermia

Laryngospasm (if using supraglottic airway)

Management

↑ FiO2 to 100%

Verify the peak inspiratory pressure

Switch to manually using reservoir bag; assess pulmonary & circuit compliance

Disconnect circuit from ETT & squeeze bag:

If PIP still high, obstruction in circuit; ventilate using BVM connected to 100% FiO2

Get help to replace/repair circuit

Auscultate chest & neck:

Listen for symmetry (endobronchial, tension, or simple pneumothorax) & for adventitious sounds (pulmonary edema, bronchospasm)

Listen for stridorous sound of laryngospasm

Examine trachea for deviation, check HR & BP

Exclude ETT obstruction:

Pass suction catheter down ETT & apply suction to clear secretions

If ETT obstructed, deflate cuff & repeat

Consider fiberoptic bronchoscopy to elucidate problem

Remove & reintubate if necessary

Check for other causes of ↓ chest compliance:

Malignant hyperthermia

Aspiration

Inadequate muscle relaxation

Opiates

Excessive surgical retraction

Abnormal anatomy (ie: scoliosis)

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9
Q

Fat Embolism

Signs
Management

A

Fat Embolism

Signs

Hypoxemia (most common early sign)

Neurological abnormalities (majority of patients)

Petechial rash (only 20-50% of patients; usually on conjuctiva, oral mucosa, skin folds of neck & axillae)

Management

Supportive treatment:

Respiratory support: intubation/ventilation, treat as ARDS (lung protective strategy)

Hemodynamic support: fluid resuscitation, vasopressors, invasive monitors, TEE

Steroids: no strong evidence but consider in refractory cases

Reduce incidence/severity:

Early immobilization of fractures

Operative correction rather than traction alone

Limitation of the intraosseus pressure during orthopedic procedures

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10
Q

Hypertension

Differential Diagnosis
Management
Complications

A

Hypertension

Differential Diagnosis

Hypoxemia, hypercarbia

Drugs:

Vasopressors, cocaine, MAOIs, stimulants

Drug errors

Acute withdrawal: EtOH, benzodiazepines, opioids, clonidine, beta-blockers

Pain, inadequate anesthesia:

Laryngoscopy/intubation

Surgical stimulation, laparoscopy

Remote (distended bladder)

Awareness

Patient factors:

Pre-existing hypertension

Pre-eclampsia

High ICP (Cushing reflex)

Autonomic dysreflexia

Endocrine:

Hyperthyroidism

Pheochromocytoma

Carcinoid

Malignant hyperthermia

Serotonin syndrome

Hyperaldosteronism

Cushing syndrome

Equipment error (falsely high reading)

Management

Inform surgeon, request cessation of surgical stimulation

Cycle BP, scan monitors for HR, ECG rhythm, EtCO2, temperature

Provided the patient is adequately oxygenated & ventilated, deepen anesthetic

Examine patient:

Pupils (high ICP)

Diaphoresis & flushing (carcinoid, pheochromocytoma, hyperthyroidism)

Rigidity (malignant hyperthermia, serotonin syndrome)

Bladder distension

Hot (thyroid storm, malignant hyperthermia, serotonin syndrome)

Examine drugs & equipment:

Potential drug error

Possible TIVA or circuit disconnect (awareness)

Tourniquet (pain)

Equipment error (falsely high reading)

Temporize​:

Labetalol 5-20mg IV q10 min (max total 300mg)

Esmolol 0.5mg/kg IV over 1 minute; start infusion at 50mcg/kg/min

Hydralazine 5-20mg IV (max 30mg) slow IV push every 20 minutes

Nitroglycerin 50-100mcg IV; start infusion at 10mcg/min

Treat underlying cause

Complications

CVS: MI, arrhythmia, CHF/pulmonary edema, dissection

CNS: intracranial hemorrhage

↑ surgical bleeding

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11
Q

Hypoxemia

Differential Diagnosis
Management

A

Hypoxemia

Differential Diagnosis

Low FiO2:

Oxygen failure or pipeline crossover of gases

Hypoventilation:

Low TV or RR

Ventilator dyssynchrony

Circuit leak

Obstructed ETT

V/Q mismatch or shunt:

Airway:

​Bronchospasm

Mainstem intubation

Mucous plug

Alveolar:

​Pulmonary edema

Aspiration

Atelectasis

Pleura:

​Pneumothorax

Pleural effusion

Deadspace:

Pulmonary embolism

Low cardiac output state

↑ metabolic O2 demand:

Malignant hyperthermia, thyrotoxicosis, sepsis, hyperthermia, neuroleptic malignant syndrome

Diffusion abnormality:

Chronic lung disease

Artifacts:

Confirm by ABG

Poor waveform (probe malposition, cold extremity, light interference, cautery)

Dyes (methylene blue, indigo carmine, blue nail polish)

Management

↑ FiO2 to 100%, high flow

Check gas analyzer to rule out low FiO2 or high N2O

Check other vitals, cycle NIBP, check peak inspiratory pressure, feel for pulse

Check ETCO2 (?extubated/disconnected/low BP)

Hand ventilate (check compliance, rule out leaks & machine factors)

Listen for breath sounds

Check position of ETT

Soft suction via ETT (to clear secretions & check for obstructions)

Consider code cart if severe

Depending on likely diagnosis, consider:

Large recruitment breaths, consider PEEP

Bronchodilators

Additional neuromuscular blockade

↑ FRC (head up, desufflate abdomen)

Fiberoptic scope to rule out mainstem intubation or ETT obstruction

ABG, CXR

Consider terminating surgery for refractory hypoxemia

Plan for post-op care

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12
Q

Malignant Hyperthermia (MH)

Signs (early and later)
DDx
Management

A

Malignant Hyperthermia (MH)

Signs (early)

↑ EtCO2

Tachycardia

Tachypnea

Mixed acidosis

Masseter spasm/trismus

Sudden cardiac arrest due to hyperkalemia

Signs (may be later)

Hyperthermia

Muscle rigidity

Myoglobinuria

Arrhythmias

Cardiac arrest

Differential Diagnosis

Neuroleptic malignant syndrome: similar presentation to MH but associated with use of antipsychotic neuroleptic medications (also treated with dantrolene)

Thyroid storm: fever, tachycardia, altered mental status

Anaphylaxis: cardiovascular collapse without hypermetabolic features

Pheochromocytoma: significant hypertension

Drug toxicity: consider clinical context, screen urine/plasma

Management

Alert surgeon & call for help

Stop anesthetic triggers (volatiles & succinylcholine), ↑ fresh gas flow to 10L/min; do not change machine or circuit

If available, insert activated charcoal filters into the inspiratory & expiratory limbs of the breathing circuit

↑ to 100% FiO2 & ↑ minute ventilation

Halt surgery; if emergent, continue with non-triggering anesthetic

Call MH hotline:

MHAUS (Malignant Hyperthermia Association of the United States)

1 800 644 9737 (within USA); 00 1 209 417 3722 (outside USA)

Assign several people to prepare dantrolene 2.5 mg/kg IV bolus:

Dilute each 20 mg dantrolene vial in 60 mL preservative-free sterile water

For 70 kg person, give 175 mg (prepare 9 vials of 20 mg dantrolene)

Rapidly administer dantrolene & continue giving until patient stable

May need > 10 mg/kg

Cool patient: IV fluids, ice packs, gastric / peritoneal lavage

Treat arrhythmias:

Usually secondary to hyperkalemia

Treat in standard fashion, however avoid calcium channel blockers

Treat metabolic acidosis:

Sodium bicarbonate 1 to 2mEq/kg PRN for base excess greater than -8

Treat hyperkalemia:

Hyperventilation

Calcium chloride 10mg/kg (max dose 2g) or calcium gluconate 30mg/kg (max 3g)

D50 1 amp IV (25g dextrose) + regular insulin 10 units IV → monitor glucose

Sodium bicarbonate 1 amp

Furosemide 0.5-1mg/kg once

For refractory hyperkalemia, consider beta-agonist, kayexalate, dialysis, or ECMO if in cardiac arrest

Monitor temperature, electrolytes, arterial/venous blood gases, creatine kinase, urine output, coagulation studies, lactic acid

Place foley catheter, monitor urine output

When stable, transfer to post anesthesia care unit or intensive care unit for at least 24 hours

Monitor for recurrence & continue dantrolene 1 mg/kg q 4-6 hours x 24 to 48 hours

Refer for genetic counseling/in-vitro muscle contracture testing

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13
Q

Increased Intracranial Pressure

Background incl signs
Management

A

Increased Intracranial Pressure

Background

Etiology:

trauma, CNS tumors, hydrocephalus, hepatic encephalopathy, impaired venous outflow

Normal ICP ≤ 15mmHg in adults

Increased ICP ≥ 20 mmHg

Intracranial components = 1400 - 1700mL total

Brain parenchyma = 80%, usually fixed in adults

CSF = 10%, can vary greatly,

Blood 10%, can vary greatly

Pathologic structures = masses, abscesses, hematomas etc.

Monro-Kellie doctrine:

Cranial compartment is a fixed volume

∴ increased in one component (blood, brain, CSF) means:

displacement of other components or;

increased ICP or;

both 1 & 2

Main compensatory mechanisms for rising ICP:

Displacement of CSF into thecal sac

Displacement of venous blood from cranial vault

Major causes of increased ICP:

Intracranial masses (i.e. tumor, hematoma)

Cerebral edema (i.e. severe infarcts, severe TBI)

Increased CSF production

Decreased CSF absorption

Obstructive hydrocephalus

Obstructed venous outflow

Idiopathic ICH

Signs:

CN VI palsies, papilledema

Decreasing GCS

Decorticate or decerebrate posturing

Cushing triad: bradycardia, respiratory depression, hypertension

Herniation syndromes

Management

Search for underlying treatable cause, for example:

Evacuating blood clot

Resection of mass

CSF drainage

R/o alternate causes of decreased GCS

hypotension, hypothermia, intoxication

ABCs

A: secure airway to allow for sedation and monitoring/controlling respiration

B: aim for hypocapnia, avoid hypoxemia

C: avoid hypotension, goal CPP 60-120mmHg with ICP monitor in-situ

Determine urgent/emergent patients:

GCS < 8

Worrisome history (i.e. head trauma or sudden thunder-clap headache)

Worrisome physical exam: Dilated & fixed pupils, decorticate/decerebrate posturing

Cushing’s triad

If true emergency patients (i.e. impending herniation):

Employ measures below before continuing with further work-up

Elevated HOB

Hyperventilate PCO2 26-30mmHg

IV mannitol (1-1.5 g/kg)

If not an emergency (increased ICP is suspected and no immediately treatable cause)

Use ICP monitoring

Goal ICP < 20mmHg

Proceed with general strategies to lower ICP as proximate cause is being investigated

General strategies to lower ICP:

Aim for euvolemia

Serum osmolality 295 to 305 mOsm/L

Avoid free water

Use 0.9% NaCl

Elevate Head of bed

Treat fevers with acetominophen

Consider neuromuscular blockade

Sedate with propofol

Consider cooling

Consider seizure prophylaxis

Specific therapies to lower ICP:

Hypertonic Saline (250mL of 7.5%)

Mannitol (1g/kg bolus, then 0.25-0.5mg/kg q6-8hrs)

Consider glucocorticoids if brain tumor or CNS infection

Hyperventilate to PaCO2 26-30 (lasts <24hrs)

Barbiturates (pentobard load 5-20 mg/kg bolus then 1-4 mg/kg/hr)

Need EEG monitoring to avoid burst suppression

Ventriculostomy if hydrocephalus is present

Remove CSF at 1-2 mL/minute for 2-3 mins at a time, aim for ICP <20mmHg

Decompressive craniectomy

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14
Q

Laryngospasm

Background
Considerations
Management
Prevention

A

Laryngospasm

Background

Involuntary closure of the vocal cords leading to airway obstruction with folding over of epiglottis

Delayed treatment can lead to:

↓O2, ↓HR, negative pressure pulmonary edema, aspiration & cardiac arrest

Considerations

Can occur anytime (induction, emergence, maintenance) while in a light plane of anesthesia

Needs to be recognized and treated rapidly

Risk factors:

Airway manipulation

Vocal cord irritation (blood or mucus etc.)

Young age (i.e. infants)

URTI

OSA

Altered airway anatomy

Procedures on the airway (e.g. tonsillectomy)

Signs & symptoms:

inspiratory stridor

Retrosternal/substernal retractions

Rocking movement with inspiration

Management

100% O2 with facemask + CPAP + optimize airway position +/- OPA

Consider Larson’s maneuver (bilateral firm digital pressure on the styloid process behind the posterior ramus of the mandible)

Deepen anesthesia (i.e. propofol or volatile agent)

Definitive treatment:

Succinycholine 0.25-0.5 mg/kg IV

Atropine 0.02mg/kg IV ready for bradycardia

BMV until muscle relaxant wears off

​​

Prevention

Delay surgery if recent URTI

Suction!

Manipulate airway only during deep plane of anesthesia

Avoid ETT (use LMA instead) for > 1 y/o’s

If intubating using NDMR

Lidocaine IV prior to extubation

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15
Q

Local Anesthetic Toxicity (LAST)

Signs & Symptoms
Management

A

Local Anesthetic Toxicity (LAST)

Signs & Symptoms

Tinnitus, metalic taste, circumoral numbess

Altered mental status

Seizures

Hypotension

Bradycardia

Ventricular arrhythmias

Cardiovascular collapse

Management

Stop local anesthetic injection &/or infusion

Call for help

Initial focus:

Airway management: ensure adequate ventilation & oxygenation; 100% FiO2, consider ETT, prevent hypoxia & acidosis (aggravate LAST)

Seizure suppression: benzodiazepines preferred, avoid/minimize propofol if hemodynamically unstable; if seizures persist, small doses of succinylcholine to minimize acidosis & hypoxia

Alert nearest facility having cardiopulmonary bypass capability

Management of cardiac arrhythmias:

If pulseless, start CPR

ACLS will require adjustment of medications & perhaps prolonged effort

Epinephrine doses <1 mcg/kg (small boluses of 10-100 mcg IV)

Avoid vasopressin, calcium channel blockers, beta blockers, & local anesthetics

If ventricular arrhythmias occur, amiodarone is preferred; avoid lidocaine & procainamide

If refractory to treatment, consider cardiopulmonary bypass

Lipid emulsion (20%) therapy:

Rapidly administer at the first signs of LAST 1.5ml/kg bolus (70kg = 105ml) over 1 minute, then start infusion at 0.25mL/kg/min

Repeat bolus once or twice for persistent cardiovascular collapse

May ↑ infusion rate (max 0.5mL/kg/min) if BP remains low

Continue infusion for at least 10 minutes after attaining circulatory stability

Recommended upper limit 10mL/kg over the first 30 minutes

Propofol is not a substitute for lipid emulsion

Failure to respond to lipid emulsion & vasopressor therapy should prompt institution of cardiopulmonary bypass (ECMO)

16
Q

Seizure

Differential Diagnosis
Management

A

Seizure

Differential Diagnosis

Epilepsy or other primary seizure disorder

Drugs:

Withdrawal syndromes (e.g. alcohol)

Drug overdoses

Illicit drugs (cocaine)

Local anesthetic toxicity

Infection:

Meningitis

Encephalitis

Sepsis

Metabolic:

Hypoglycemia

Hypoxemia/hypercarbia

Hyponatremia/hypocalcemia/hypomagnesemia

Toxins (uremic, hepatic encephalopathy)

Dialysis disequilibrium syndrome

Porphyria

Structural:

​Ischemic or hemorrhagic stroke

Intracranial tumor

Cerebral edema

Pregnancy:

Eclamptic seizure

Amniotic fluid embolism

Management

Inform surgical team & call for help

Supplemental oxygen, monitors, establish IV access

If needed, hand ventilate with 100% O2 - DO NOT hyperventilate (↓ seizure threshold)

Focused cardiorespiratory & neurological exams

Rapid glucometer

Bloodwork: CBC, electrolytes, extended electrolytes, blood glucose, liver enzymes, kidney function tests, ABG

Give anticonvulsants if seizure > 2min:

Benzodiazepines = 1st line

Midazolam 0.05mg/kg or 1mg at a time, titrate to effect

Diazepam 0.1-0.4mg/kg IV, 0.04-0.2 mg/kg PR

Lorazepam 1-2 mg at a time, titrate to effect

Propofol 0.5mg/kg at a time, titrate to effect

Phenytoin 20mg/kg total loading dose at a rate of 50mg/min, watch for hypotension & arrhythmias

Barbiturates:

Phenobarbital 20 mg/kg infused at a rate of 50 mg/minute

Thiopental 25-100mg dose

Pentobarbital 10 mg/kg infused at a rate of up to 100 mg/minute

Valproic acid IV 30mg/kg over 15 min

Consult neurology for further diagnosis & management

If ↑ ICP: institute treatment (mannitol, furosemide, hypertonic saline, mild hyperventilation, elevate HOB, etc)

If eclampsia: MgSO4 4g IV bolus over 15 min, then 1-2g/hr

If no resolution & respiratory compromise:

Paralyze & intubate

Succinylcholine IM (4mg/kg) for intubation if no IV access

17
Q

Perioperative MI

Signs
Management

A

Perioperative MI

Signs

New ST segment or T wave changes

New left bundle branch block

Arrhythmias, conduction abnormalities

Unexplained tachycardia, bradycardia, or hypotension

Development of pathological Q waves

Regional wall motion abnormalities or new/worse mitral regurgitation on TEE

Management

Assess need for airway management & initiation of cardiopulmonary resuscitation

Verify ischemia (12 lead ECG or expanded monitor view)

Optimize myocardial oxygen supply:

​↑ FiO2

Treat anemia if present

Optimize BP (maintain coronary perfusion pressure) & HR (avoid tachycardia)

↓ coronary oxygen demand:

Analgesia

Nitrates (careful in hypotension)

Beta blockers (careful in hypotension & acute heart failure)

Optimize BP (avoid increased afterload) & HR (avoid tachycardia)

Discuss aborting procedure with surgical team

Discuss aspirin & anticoagulation with surgical team & cardiology team

Send labs: troponin, CBC, ABG

Initiate invasive monitoring, consider central venous access

Consider TTE/TEE for monitoring volume status & regional wall motion abnormalities

If hemodynamically unstable, consider intra-aortic balloon pump

Admit to HAU/ICU/CCU

18
Q

Postoperative Visual Loss

Differential Diagnosis
Risk Factors
Management

A

Postoperative Visual Loss

Differential Diagnosis

Corneal abrasion

Ischemic optic neuropathy (ION)

Central/branch retinal artery occlusion (CRAO, BRAO)

Cortical blindness secondary to visual field stroke

Transient ischemic attack (TIA)

Acute glaucoma

Expansion of intraocular vitrectomy gas bubble (nitrous oxide)

TURP glycine toxicity

Risk Factors

External eye compression from improper patient positioning

Retrobulbar hemorrhage due to vascular injuries following sinus/nasal surgery

Retinal microemboli associated with open-heart surgery

Prone positioning

Lengthy spinal fusion surgery, ↓ arterial pressure, ↑ blood loss, anemia, high volume crystalloid resuscitation

Cardiothoracic, instrumented spinal fusion surgeries, head & neck, nose or sinus surgeries

Systemic vascular risk factors: hypertension, diabetes, atherosclerosis, hyperlipidemia, smoking, obesity, obstructive sleep apnea & hypercoagulability

Management

Immediate normalization of vital signs & metabolics

Urgent ophthalmology consultation +/- neurology consultation

CRAO:

Ocular massage to dislodge clot

Localized hypothermia to affected eye

Acetazolamide (500mg IV)

Inhaled CO2 (mixture of 95% oxygen & 5% carbon dioxide)

Anterior chamber paracentesis

Intraarterial fibrinolysis

ION:

Elevate head of bed

​Correct volume depletion & blood loss

Restore BP to normal range

Potential benefit from acetazolamide, mannitol, furosemide

Steroids, hyperbaric oxygen controversial

Surgeon to bedside for multidisciplinary debriefing with patient & family

Call CMPA for counselling around disclosure & documentation

19
Q

Tension Pneumothorax


Background
Signs
Management

A

Tension Pneumothorax


Background

A tension pneumothorax happens when air in the pleural space builds up enough pressure to reduce venous return, resulting in hypotension, tachycardia and severe dyspnea.

Patients receiving mechanical ventilation are more likely to progress to cardiovascular collapse

Signs

Tachycardia and Hypotension

High airway pressure and oxygen desaturation

Contralateral shift of the trachea

Management

Notify surgeon and call for help as necessary

Apply 100% oxygen and reduce anesthetic agents

Treat hypotension with fluids and pressors as required

Decompress the pneumothorax immediately

14G needle at the 2nd intercostal space in the midclavicular line

Definitive management with chest tube insertion by qualified personnel

20
Q

Total Spinal

Signs
Management

A

Total Spinal

Signs

Numbness or weakness in upper extremities

Nausea/vomiting

Dyspnea/respiratory depression

Loss of consciousness

Bradycardia

Hypotension

Dilated pupils

Management

Supportive care:

Assess need for intubation and/or cardiopulmonary resuscitation

Maintain oxyvenation/ventilation & protect against aspiration

Support hemodynamics:

IV fluid bolus, atropine, epinephrine (10 - 100ug IV, increase as needed)

If pregnant: left uterine displacement & fetal heart rate monitoring

Consider sedation when hemodynamically stable

Change position based on baricity (careful with reverse trendelenberg & hypotension → venous pooling)

Support until spinal wears off

21
Q

Transfusion Reactions

General Management
Signs and management for:
- Acute hemolytic reaction
- Febrile nonhemolytic reaction
- Anaphylaxis
- Transfusion-associated circulatory overload (TACO)
- Transfusion-related acute lung injury (TRALI)
- Urticarial reaction

Complications

A

Transfusion Reactions

General Management

Stop transfusion

Support blood pressure with IV fluids, vasoactive medications if needed

Notify blood bank of all possible reactions

Determine diagnosis

Acute hemolytic reaction

Signs:

Awake: chills, fever, nausea, chest & flank pain

Anesthetized: hyperthermia, tachycardia, hypotension, hemoglobinuria, diffuse oozing in surgical field

Management:

Stop transfusion & notify blood bank

Support hemodynamics

Recheck unit against blood slip & patient’s identity bracelet

Draw bloodwork to identify hemoglobin in plasma, repeat compatibility testing, obtain coagulation studies & platelet count

Insert urinary catheter & check urine for hemoglobin

Initiate osmotic diuresis with IV fluids +/- mannitol

Monitor for hyperkalemia, DIC

Febrile nonhemolytic reaction

Signs:

Fever

No evidence of hemolysis

Management:

Antipyretics

Transfusion may be continued if reaction mild

Use leukoreduced transfusions in the future

Anaphylaxis

Signs:

Rash/hives

Angioedema

Hypotension

Tachycardia

Hypoxemia

Bronchospasm/wheezing

Increased peak inspiratory pressure

Management:

​Stop transfusion

Epinephrine

IV fluids

Antihistamines, corticosteroids

See “Anaphylaxis” page for further details

Transfusion-associated circulatory overload (TACO)

Signs:

Respiratory distress, hypoxia

↑ BP

Acute or worsening pulmonary edema

Positive fluid balance

Management:

Stop transfusion

Supplemental oxygen

Diuretics

Transfusion-related acute lung injury (TRALI)

Signs:

Acute hypoxia & noncardiac pulmonary edema within 6 hours of transfusion (usually plasma)

↓ BP

Management:

Supplemental oxygen, endotracheal intubation / ventilation

Similar treatment to acute respiratory distress syndrome (ARDS)

Hemodynamic support

Urticarial reaction

Signs:

Erythema, hives, itching

No fever

Management:

Antihistamines, steroids

Transfusion may be continued if reaction mild

Complications of Massive Transfusion

Dilutional coagulopathy

Hypothermia

Hyperkalemia

Complications of citrate infusion:

Hypocalcemia

Metabolic acidosis or alkalosis

22
Q

Venous Air Embolism

Signs
Management (includes goals)

A

Venous Air Embolism

Signs

Air on TEE or change in doppler tone if monitoring

↓ ETCO2

↓ BP

↓ SpO2

↑ CVP

Bronchospasm

Dyspnea & respiratory distress or cough in awake patient

Mill wheel murmur on cardiac auscultation (late sign)

Management

Goals: prevent further entrainment of air, hemodynamic support, treat existing air

Inform surgeon

Flood surgical field with saline & apply bone wax

Supportive therapy:

​100% oxygen, decrease or turn off volatile anesthetic

Stop nitrous oxide

IV fluid bolus

Vasopressors (epinephrine, norepinephrine, dobutamine)

Positioning:

Place surgical site below heart (if able)

Lower the head position & compress the jugular veins (if surgical site above the neck)

Reposition the patient into left lateral decubitus, trendelenberg, or left lateral decubitus head down position (controversial - poor evidence & often impractical to do in the OR)

Definitive therapy:

Hyperbaric oxygen therapy (especially if paradoxical air embolism)

Aspirate air from the central catheter if in situ

Chest compressions

PEEP is of no value & increases risk of paradoxical air embolism

Consider TEE to assess air & RV function

23
Q

Hypoglycemia

Signs
DDx
Management

A

Hypoglycemia (blood glucose <3.9 mmol/L)

Signs

Sympathetic system activation: diaphoresis, tremor, tachycardia, anxiety, hunger

Neuroglycopenia: weakness, fatigue, altered mental status, coma

Differential diagnosis

Exogenous insulin

Critical illness/sepsis

Endocrine: Addison’s disease, adrenal crisis, hypopituitarism

Insulin producing tumors

Fasting hypoglygemia: inherited liver/fatty acid oxidation enzyme deficiencies, drugs (ethanol, haloperidol)

Reactive (postprandial) hypoglycemia: idiopathic or enzyme deficiencies

Management

Confirm glucose level

Treat: IV dextrose (D5W 50ml IV); glucagon 1-2mg IM if no IV access

Seizure precautions

Continue to monitor & treat until glucose levels stable

24
Q

Hypotension

Differential Diagnosis
Management

A

Hypotension

Differential Diagnosis

↓ preload:

Bleeding

Relative

↓ afterload/distributive shock:

Anaphylaxis

Sepsis/SIRS

Neurogenic

Blood transfusion reaction

Neuraxial

Drugs: anethetic overdose/drug swap

Endocrine: Addison’s, myxedema, carcinoid

Metabolic: hypocalcemia, hypoglycemia

Obstructive shock:

Tension pneumothorax

Tamponade

Embolic events

Pulmonary hypertension

Cardiogenic shock:

Rate:

Bradycardia

Tachycardia

Arrhythmias

Contractility:

Ischemia

Drugs or toxins

RV failure/pulmonary hypertension

Acute valvular pathology

Management

Emergency situation requiring simultaneous diagnosis & management

Inform the surgeon

Call for help

↓ anesthetic & hand ventilate with 100% O2

Vasopressor bolus +/- IV fluid bolus:

​Phenylephrine 100 mcg IV PRN

Norepinephrine 5 mcg IV PRN

Ephedrine 5-10 mg IV PRN

Epinephrine 1-10 mcg IV PRN

Cycle BP & scan monitors for HR, rhythm, ST changes, SaO2, EtCO2, PAP

Feel for a pulse:

If no pulse → ACLS as per protocol

Ensure crash cart in room:

If pulse present → targeted physical exam

Urticaria, flushing, angioedema

Tracheal deviation, jugular venous distention, subcutaneous crepitus, bilateral air entry

JVP (jugular venous pressure) / CVP (central venous pressure) / PCWP (pulmonary capillary wedge pressure)

↑ CVP / PCWP = obstructive or cardiogenic

↓ CVP / PCWP = hypovolemic or distributive

Peripheral perfusion (↑ in distributive, ↓ in others)

Look at surgical field (blood loss, IVC compression, pneumoperitoneum pressure)

Check IV fluids, vasopressors, blood products

Reassess differential diagnosis based on findings