BRS Emergency Medicine - L. Stead (Lippincott, 2000)

1. Resuscitation, Basic Life Support, and Advanced Cardiac Life Support

I. Airway

§  Airway, breathing, and circulation are the three components of the ABCs, the first issues that must be addressed in any patient encounter.

§  Patency of the airway is checked by clinical presentation. If the patient can cough or speak, the airway is at least partially patent.

§  Some of the more common causes of airway obstruction include:

§  foreign bodies (especially in children)

§  edema (as with anaphylaxis)

§  lax tongue falling back into the pharynx in an obtunded patient.

§  The presence of stridor (high-pitched, upper airway, inspiratory sounds) usually indicates some degree of obstruction.

§  If the airway is obstructed, opening the airway is attempted, as outlined in section IV.

§  If the Basic Life Support (BLS) techniques fail, more definitive airway management must be undertaken.

A. Indications for intubation

1.   Failure to maintain a patent airway

§  Burn injury to airway and penetrating neck trauma may result in failure to maintain a patent airway.

2.   Failure to protect the airway

§  Aspiration, status epilepticus, drug overdose, severe head injury (GCS <9), or central nervous system (CNS) lesions may result in failure to protect the airway.

§  Suggestive clues include inability to handle secretions and absence of gag and swallow reflexes.

3.   Hypoxia refractory to oxygenation via face mask

B. Types of intubation

1.   Blind nasotracheal intubation

§  The diameter of the tube must be 0.5–1.0 mm smaller than the corresponding endotracheal tube size (see I B 2). In children, the size of the tube can be estimated to be the size of the child's fifth digit.

§  The depth of the tube (from the external nares to 5 ± 2 cm above the carina) should be 26 cm in women and 28 cm in men.

c.   Indications include inability to open mouth (secondary to severe oral trauma or trismus), a short, thick neck, and inability to move the neck.

d.   Contraindications include apnea, head trauma (e.g., basilar skull or central facial fracture), CSF rhinorrhea, an expanding neck hematoma, an uncooperative patient, choanal atresia, known bleeding diathesis, and an anticipated need for thrombolytic therapy

e.   Complications include epistaxis, nasal septum or turbinate trauma, airway obstruction from bleeding, sinusitis (long-term), and retropharyngeal lacerations (rare).

§  violation of cranial vault by blind nasotracheal intubation in cases of trauma

2.   Endotracheal intubation

§  is the method most commonly used.

§  is the mainstay of difficult intubations.

§  requires direct visualization of the airway (Figure 1-1).

§  The diameter of the tube should be 6.5–8.0 mm in women and 8.0–8.5 mm in men. In children, the size of the tube is calculated as follows: (age in years/4) + 4 mm.

§  The depth of the tube (distance from lips to 5 ± 2 cm above the carina) should be 21 cm in women and 23 cm in men. In children, the depth is calculated as follows: (age in years/2) + 12 cm.

e.   Methods for checking endotracheal tube (ETT) placement

1.   Direct visualization of the tube passing through the vocal cords (see Figure 1-1)

Figure 1-1. (A) Endotracheal intubation. (B) Note direct visualization of the V-shaped vocal cords. (Adapted from LifeART. Copyright 1998, Lippincott Williams & Wilkins. All rights reserved.)

f.    

g.   

1.   Pulmonary and gastric auscultation

2.   Condensation in ETT

3.   Aspiration technique

§  Easy aspiration suggests tube is positioned in the trachea.

§  Difficult aspiration suggests tube is positioned in the esophagus.

4.   Resistance to bagging (suggests esophageal intubation)

5.   Chest radiograph: tip of ETT should be aligned with T3 vertebra

6.   End-tidal carbon dioxide detector

h.   Contraindications include

§  massive orofacial trauma

§  hemorrhage and severe trismus

i.    Complications include

§  vocal cord damage secondary to laryngospasm (can be prevented by anesthetizing vocal cords before procedure)

§  subglottic stenosis

§  esophageal or right main-stem bronchus intubation

§  dental trauma

§  cervical spine injury

3.   Rapid sequence intubation (RSI)

§  is a technique in which sedation and neuromuscular blockade are used virtually simultaneously without positive pressure ventilation in between.

§  fastest method to obtain a definitive airway

§  low complication rate

c.   Indications include inability of patient to cooperate with awake intubation, altered mental status, seizure activity, trismus of oral muscles, severe trauma, and increased intracranial pressure (ICP).

d.   Potential complications include vomiting and subsequent aspiration, because in emergent settings one must assume the patient has a full stomach.

e.   The procedure involves

§  preparation of all equipment (e.g., checking ETT balloon, suction, bag valve mask device, and pulse oximetry).

§  preoxygenation (5 minutes of 100% oxygen by non-rebreather mask).

§  pretreatment (Tables 1-1 and 1-2).

1.   For patients with increased ICP, use lidocaine or fentanyl.

2.   For preventing succinylcholine-associated muscle fasciculations, use a “priming” dose (0.01 mg/kg) of a competitive neuromuscular blocking agent such as atracurium, rocuronium, pancuronium, or vecuronium.

3.   For children use atropine 0.01–0.02 mg/kg IV to prevent the paradoxical bradycardia associated with succinylcholine to which children are especially susceptible.

§  sedation with thiopental, methohexital, etomidate, midazolam, diazepam, fentanyl, or ketamine

Table 1-1. Induction Agents used in Rapid Sequence Intubation

Induction Agent

IV Dose

Onset of Action

Duration of Action

Indications

Contraindications

Thiopental

3.0–5.0

< 1 min

5–10 min

↑ ICP

Hypotension, asthma, cardiogenic shock, pulmonary edema

Methohexital

1.0–3.0 mg/kg

< 1 min

5–10 min

↑ ICP

Seizures, hypotension, asthma

Etomidate

0.3 mg/kg

< 1 min

5 min

↑ ICP, CAD

Age < 10 years, pregnant/lactating, myoclonic epilepsy, severe hepatic disease

Fentanyl

3–15 µg/kg

2–4 min

45 min

↑ ICP

Hypotension

Midazolam

0.5–1.0 mg/kg

< 1 min

6–15 min

↑ ICP

Hypotension

Diazepam

0.04–0.3 mg/kg (children); 5–10 mg (adults)

1–2 min

2–4 h

↑ ICP

Hypotension

Ketamine

1.0–1.5 mg/kg

1 min

10–20 min

Status asthmaticus

Head trauma, ↑ ICP

Propofol

1.5–3.0 mg/kg

< 1 min

5–10 min

↑ ICP

Hypotension, severe CAD

CAD = coronary artery disease; ICP = increased intracranial pressure.

f.  

g.   

§  paralysis with a noncompetitive neuromuscular blocking agent (e.g., succinylcholine) (see Table 1-2).

4.   Cricothyrotomy

§  is a surgical airway through the cricothyroid membrane

§  provides a definitive airway

§  is an invasive technique

c.   Indications include

§  massive trauma to the nose and mouth

§  uncontrollable oral hemorrhage

§  inhalation injury resulting in massive nasal and oral edema

§  inability to control the airway with other methods

d.   Contraindications include

§  laryngeal injury

§  patient age under 10 years (because the cricothyroid membrane in children is too small) [Figure 1-2]

Table 1-2. Neuromuscular Blocking Agents Used in Rapid Sequence Intubation

Depolarizing Agent

IV Push Dose

Onset of Action

Duration of Action

Continuous IV Infusion Rate

Noncompetitive
   Succinylcholine


1.0–1.5 mg/kg (can use 3–4 mg IM in children if no IV access)


30 sec


3–5 min


0.5–1.0 mg/min

Competitive
   Atracurium
   Rocuronium
   Pancuronium
   Vecuronium


0.5 mg/kg
0.8 mg/kg
0.1 mg/kg
0.1 mg/kg


2–5 min
1–2 min
3–5 min
2–3 min


20–45 min
30–45 min
80–100 min
20–40 min


0.4–0.8 mg/kg/h
0.6–0.72 mg/kg/h
0.02–0.1 mg/kg/h
0.1 mg/kg/h

IM = intramuscular; IV = intravenous.

e.

f.    

§  ability to intubate safely by other methods

§  In children under 10 years of age, a needle cricothyrotomy with percutaneous transtracheal ventilation is preferred.

g.   Complications include excessive hemorrhage, aspiration, prolonged hypoxic state (because of time this technique requires), trauma to vocal cords and thyroid, esophageal perforation, subcutaneous emphysema, and altered phonation.

II. Breathing

§  Once the airway is secured, attention is directed to breathing.

A. Oxygen delivery devices

§  Any patient in respiratory distress or with potential for hypoxia should receive supplemental oxygen, with the goal of keeping oxygen saturation above 96%.

§  Table 1-3 summarizes the methods used to deliver oxygen.

Figure 1-2. Airway anatomy. Note the differences between the adult (A) and pediatric (B) airways. (Adapted from LifeART. Copyright 1998, Lippincott Williams & Wilkins. All rights reserved.)

 

Table 1-3. Oxygen Delivery Devices

Delivery Devices

Oxygen Concentration (%)

Flow Rate (L)

Indications

Nasal cannula

25–45

1–6

Conscious, spontaneously breathing patient; not appropriate for arrest setting

Venturi mask

40–60

4–10

Conscious spontaneously breathing patient; not appropriate for arrest setting

Non-rebreather mask

80–95

8–12

Conscious, spontaneously breathing patient; not appropriate for arrest setting

Bag–valve–mask device

100

12–15

Apneic, nonintubated patients

B. Mechanical ventilation

§  In intubated patients, the work of breathing may be assisted by ventilators.

1.   Ventilators have several modes (Table 1-4).

2.   Certain ventilator settings are manually preset, such as respiratory rate (RR), tidal volume (TV), percent of oxygen content of inspired gas (FIO2), and positive end-expiratory pressure (PEEP).

a.   RR is set at 8–12 breaths/min in patients with normal lungs. A rate of 5–6 breaths/min may be used for patients with obstructive lung disease to facilitate permissive hypercapnia. For patients in whom hyperventilation is desired (e.g., head trauma, cerebral edema), RR may be set as high as 18–20 breaths/min.

b.   The TV is set at 5–15 ml/kg in patients with normal lungs. The aim is to adjust TV to keep peak airway pressures < 35 mm Hg; however, too low a TV may result in hypoxia and atelectasis.

c.   FIO2 is set at 0.2–1.0 in patients with normal lungs. The initial setting is 0.5. The aim is to set the lowest FIO2 that will produce an oxygen saturation > 90% and a partial pressure of oxygen (PO2) > 60 mm Hg. Increase the FIO2 setting in patients with fever, hypercarbia, acidemia, and blood dyscrasias in whom the oxygen saturation is inherently compromised.

d.   PEEP is used when an acceptable oxygen saturation (i.e., > 90%) is not achievable with a desirable FIO2 (i.e., < 0.5). Start with 5 cm H2O and increase at 15-minute intervals by 3 cm H2O until desired parameters are reached. PEEP improves oxygenation by keeping the alveoli patent during expiration and narrows the alveolar-arterial oxygen difference.

3.   Monitoring. Patients on mechanical ventilation

§  should be monitored to ensure that optimal ventilation and perfusion conditions are maintained, especially when the patient is totally paralyzed and cannot breathe spontaneously.

Table 1-4. Ventilator Modes

Ventilator Mode

Description

Advantages and Indications

Disadvantages

CMV

Ventilator delivers a preset volume regard- less of patient effort; spontaneous breaths not allowed (patient cannot breathe between mechanical breaths)

Useful for apneic, paralyzed, comatose, and acute overdose patients and those being deliberately hyperventilated (e.g.,  ICP)

Respiratory alkalosis may result, requires neuromuscular paralysis and sedation, difficult to wean

AC

Ventilator responds to patient's spontaneous effort, ensuring adequate tidal volume; if no patient effort, then cycles at preset rate.

Good initial choice of ventilator mode in conscious patients

Allows patients to spontaneously (self) hyperventilate

IMV

Equivalent to CMV + spontaneous breathing; ventilator does not assist patient but allows spontaneous breathing while delivering a predetermined number of tidal volumes

Requires less sedation than CMV or AC and no neuromuscular paralysis, good for muscle conditioning, less tendency for patient to self-hyperventilate

Breath stacking

SIMV

Equivalent to AC + spontaneous breathing; similar to IMV, but synchronized to patient's breathing; mechanical breath either coincides with a spontaneous breath or falls between spontaneous breaths

Prevents breath stacking, facilitates weaning, useful for obstructive airway disease

Requires intact respiratory effort

PS

Maintains airway at a constant preset inspiratory pressure until patient's inspiratory flow falls below 25% of peak level

Lowest peak airway pressure of all modes, requires less patient work, facilitates weaning, useful for restrictive airway disease

Requires spontaneously breathing patient, not good for patients with fluctuating respiratory effort or pulmonary compliance

AC = assist control; CMV = controlled mechanical ventilation; IMV = intermittent mandatory ventilation;
PS = pressure support; SIMV = synchronized intermittent mandatory ventilation.

4.   

5.   

§  should be placed on a cardiac monitor to check blood pressure, pulse, and oxygen saturation. It may also be desirable to monitor cardiac output, pulmonary capillary wedge pressure, and central venous pressure by means of a Swan-Ganz catheter. Bilateral breath sounds should be confirmed periodically in order not to miss a pneumothorax.

§  An arterial blood gas (ABG) should be obtained 15 minutes after the initial ventilator settings are made and after each change in the ventilator settings to assess partial pressure of carbon dioxide (PCO2).

c.   In most patients, a PCO2 of 40 mm Hg is desirable.

d.   In patients who are being deliberately hyperventilated, PCO2 is targeted to 28–30 mm Hg.

e.   In patients with chronic carbon dioxide retention, PCO2 is targeted to 50 mm Hg.

6.   Adverse effects

 .    Barotrauma can result from high pressures, which can lead to

§  pneumothorax (tension pneumothorax is the most common complication)

§  pulmonary interstitial emphysema

§  subcutaneous emphysema

§  pneumomediastinum

§  pneumoperitoneum

§  air embolism

a.   Decreased cardiac output can result from decreased venous return to the right side of the heart secondary to increased intrathoracic pressure. Decreased cardiac output often is associated with PEEP > 15 cm H2O and can lead to

§  increased ischemia of the gastric mucosa and secondary bleeding

§  decreased renal blood flow, leading to renal insufficiency and decreased urinary output

§  decreased hepatic flow, leading to increased hepatic vessel resistance

b.   Oxygen toxicity can result in retrolental fibroplasia and is associated with high FIO2 settings.

c.   Pneumonia is associated with nonsterile technique and poor humidification of the ventilation system. The most common infectious organisms are gram-negative enteric bacteria.

d.   Ulceration, stenosis, or necrosis of the nasopharynx and oropharynx also may occur.

III. Circulation

§  is focused on after the airway and breathing have been addressed.

§  is addressed by monitoring vital signs, establishing IV access, controlling hemorrhage, and providing chest compressions as necessary.

A. Vital signs

(i.e., pulse and blood pressure)

§  The pulse is a quick, noninvasive way of determining gross circulatory status.

1.   A palpable radial pulse denotes an approximate systolic blood pressure (SBP) of 80 mm Hg.

2.   A palpable femoral pulse denotes an approximate SBP of 70 mm Hg.

3.   A palpable carotid pulse denotes an approximate SBP of 60 mm Hg.

B. Capillary refill time

§  is another quick, easy gauge of perfusion.

§  is the time it takes for color to return to a blanched nail bed.

§  normal capillary refill time is 2–3 seconds, with 5 seconds considered abnormally delayed.

C. IV access

1.   Peripheral access

§  is often faster than central line placement.

§  affords excellent access for volume replacement when done with two large-bore needles (14- to 16-gauge) in the antecubital or upper arm veins.

§  In infants and small children [i.e., < 11 kg (24 lb)], a 22- to 24- gauge needle should be used.

§  In older children, an 18- to 22-gauge needle may be more appropriate.

2.   Central access

§  may be obtained via different veins.

§  Each approach has its own advantages and disadvantages (Table 1-5).

3.   Intraosseous (IO) access

§  is used in children when IV access is difficult to obtain.

§  is attempted via the anteromedial aspect of the tibia or the distal femur.

§  The marrow of the bone drains into the central venous system, and may provide faster access.

§  Virtually all drugs that can be given IV can also be given IO.

D. Chest compressions

1.   Closed compressions (see IV B 2)

Table 1-5. Comparison of Different Approaches for Central Venous Access

Central Venous Access

Advantages

Disadvantages

Subclavian

Left preferred over right for transcutaneous pacing, low infection rate, most comfortable for patient

Least safe during a code, highest risk of pneumothorax (2%), interference with CPR, contraindicated in the presence of clavicular fracture

Internal jugular

Less risk of pneumothorax compared to subclavian, easier access during CPR compared to subclavian, right preferred over left due to anatomy, fastest circulation time

Increased risk of carotid artery puncture, least comfortable for patient

Femoral

Safest in acute situations (trauma, code), no risk of pneumothorax, easiest access during a code

Highest incidence of infection, increased risk of thrombosis, slowest circulation time

CPR = cardiopulmonary resuscitation.

2.   Open compressions

§  are done after thoracotomy in cases of penetrating trauma to the chest.

§  are most successful if done within 20 minutes of cardiac arrest.

IV. Basic Life Support (BLS)

A. Foreign body airway obstruction

1.   Conscious victim

a.   Determine obstructed airway.

§  Shout “Can you cough?” and “Can you speak?”

§  Look for the universal distress signal (i.e., a hand wrapped around the throat). Inability to make vocal sounds or the presence of stridor also usually signals an obstructed airway.

b.   Activate the emergency medical system (EMS).

c.   Clear the airway.

1.   In adults and children, use the Heimlich maneuver.

§  Stand behind the victim with your fists two fingerbreadths below the xiphoid process.

§  Deliver upward abdominal thrusts until the airway is cleared (i.e., foreign body is expelled) or the victim becomes unconscious.

2.   In infants, use an alternative method consisting of back blows and chest thrusts, because the force of the Heimlich maneuver may result in rupture of abdominal organs.

§  With the infant placed prone over the rescuer's forearm, deliver five forceful back blows between the infant's shoulder blades using the heel of the hand.

§  Next, while carefully supporting the head and neck, turn the infant to a supine position with the head lower than the trunk and deliver five quick downward chest thrusts with 2–3 fingers of one hand one fingerbreadth below the nipple line.

§  Continue alternating back blows with chest thrusts until the foreign body is expelled or the victim becomes unconscious.

2.   Unconscious victim

a.   Determine unresponsiveness.

§  Shout “Are you okay?”

b.   Activate the EMS.

c.   Open the airway.

§  Use the head tilt-chin lift method (Figure 1-3A) unless C-spine injury is suspected.

§  If C-spine injury is suspected, use the modified jaw thrust maneuver (Figure 1-3B).

d.   Determine breathlessness.

§  Observe the chest (i.e., look, listen, and feel for breathing) for 5 seconds.

e.   Ventilate.

 

Figure 1-3. Head positioning techniques for opening the airway. (A) Head tilt-chin lift technique to open airway.(B) Jaw thrust technique to open airway. This technique is used when C-spine injury is suspected. (Adapted from LifeART Emergency Medicine Professional Collection. Copyright 1998, Lippincott Williams & Wilkins. All rights reserved.)

§  Maintain an open airway, seal the mouth, and pinch the nose. If using a bag-valve-mask device, place the mask over the nose and mouth.

§  Give two full breaths (or squeezes).

§  If ventilation is unsuccessful, reposition the head and repeat the procedure.

§  If ventilation still is unsuccessful, it is likely that the airway is obstructed.

f.    Clear the airway.

§  Use the Heimlich maneuver for adults and children [see IV A 1 c (1)].

§  Use alternating back blows and chest thrusts for infants [see IV A 1 c (2)].

g.   Check for foreign bodies.

§  Open the mouth with the head tilt-chin lift or cross-finger technique.

§  Do a finger sweep to locate the foreign body.

h.   Ventilate.

§  Repeat the ventilation sequence (see IV A 2 e) until airway is clear (rescue breathing).

§  This ventilation sequence should be repeated once every 5 seconds in adults and once every 3 seconds in children.

§  The major adverse effect associated with rescue breathing is gastric distention, especially in children. To minimize this risk, rescue breathing is performed with slow breaths given over 1.0–1.5 seconds, of volume just sufficient to cause the chest to rise.

B. Cardiopulmonary resuscitation (CPR)

1.   Determine pulselessness.

§  Locate the carotid artery and feel for a pulse (5 seconds).

§  If the victim has no pulse, circulation must be provided in addition to breathing.

§  In children, locating a pulse may be difficult. However, because cardiac arrest in children usually is secondary to respiratory arrest, a child who is not breathing probably also has circulatory compromise.

2.   Begin closed chest compressions.

a.   Adults

§  If there is no pulse, locate the landmark for closed chest compressions, which is 2–3 fingerbreadths above the xiphoid process.

§  With the heel of one hand on the sternum and the heel of the other hand on top of the first hand, give chest compressions that are 1.5–2.0 inches deep, at the rate of 80–100/min.

§  In one-person CPR, the ratio of chest compressions to breaths is 15:2. In two-person CPR, the ratio of chest compressions to breaths is 5:1.

§  Take 5 seconds to check for pulse after the first minute, and then check every few minutes.

b.   Children and infants

§  Using 2–3 fingers of one hand, compressions are given one fingerbreadth below the nipple line at a depth of 0.5–1.0 inch, at a rate of at least 100/min.

§  The ratio of chest compressions to breaths is 5:1.

3.   Activate the EMS

 .    Adults

§  Immediately activate the EMS.

a.   Children

§  Perform 1 minute of rescue breathing before activating the EMS system, because pediatric cardiac arrest is primarily respiratory in origin.

V. Cardiopulmonary Arrest and Advanced Cardiac Life Support (ACLS)

§  ACLS picks up where BLS leaves off (i.e., at CPR).

§  Figure 1-4 is the universal ACLS algorithm devised by the American Heart Association.

A. Ventricular tachycardia (VT)

[Figure 1-5] and ventricular fibrillation (VF) [Figure 1-6]

§  Check for VT/VF on the monitor.

1.   For treatment of VT with a pulse, see V E 1.

2.   For treatment of VT without a pulse, treat like VF, as outlined below (Figure 1-7).

a.   Defibrillate (shock) three times.

§  Defibrillate at 200 J, 300 J, and 360 J in adults. In children, defibrillate at 2 J/kg, then at 4 J/kg, and again at 4 J/kg.

§  Check the rhythm after each shock before proceeding to the next one.

b.   Check for VT/VF.

§  If VT/VF is persistent, continue CPR, oxygenate, and obtain IV access.

 

Figure 1-4. Universal advanced cardiac life support (ACLS) algorithm. ABCs = airway, breathing, circulation; CPR = cardiopulmonary resuscitation; ECG = electrocardiogram; EMS = emergency medical services; IV = intravenous. (Reproduced with permission. Advanced Cardiac Life Support, 1997. Copyright American Heart Association.)

c.   Deliver another shock at the intensity last used, followed by administration of epinephrine.

§  Give adults 1 mg of epinephrine IV push, and repeat every 3–5 minutes until a pulse is established.

§  Give children 0.01 mg/kg IV push of epinephrine, and repeat every 3–5 minutes at a dose of 0.1 mg/kg.

d.   Administer the following medication sequence if VT/VF persists.

Defibrillate at 360 J (adults) or 4 J/kg (children) and check the rhythm on the monitor after each dose of medication.

Figure 1-5. Ventricular tachycardia. (Adapted from LifeART Emergency Medicine Professional Collection. Copyright 1998, Lippincott Williams & Wilkins. All rights reserved.)

§  Administer lidocaine 1.0–1.5 mg/kg IV push. (Note: a single dose of 1.5 mg/kg lidocaine is acceptable for cardiac arrest). Repeat in 3–5 minutes to a maximum dose of 3 mg/kg.

§  Administer bretylium 5 mg/kg IV push. Repeat once at 10 mg/kg IV push.

§  Administer magnesium sulfate 1–2 mg IV for suspected hypomagnesemic states and torsades de pointes.

§  Administer procainamide for persistent refractory VF. Administer 30 mg/min to a maximum total dose of 17 mg/kg.

B. Pulseless electrical activity (PEA) [electromechanical dissociation]

1.   Causes of PEA can be summarized by the acronym, MATCH4ED.

§  M: massive myocardial infarction

§  A: acidosis

§  T: tension pneumothorax

§  C: cardiac tamponade

§  H4: hypovolemia, hypoxia, hypothermia, hypokalemia

§  E: embolism

§  D: drug overdose (e.g., tricyclics, β-blockers, calcium channel blockers)

2.   Treatment

a.   Intubate the patient and obtain IV access.

b.   Treat any underlying conditions.

c.   Administer epinephrine.

Figure 1-6. Ventricular fibrillation.

d.   

e.   

Figure 1-7. Algorithm for treatment of ventricular fibrillation/pulseless ventricular tachycardia (VF/VT). ABCs = airway, breathing, circulation; CPR = cardiopulmonary resuscitation; IV = intravenous; PEA = pulseless electrical activity. (Reproduced with permission. Advanced Cardiac Life Support, 1997. Copyright American Heart Association.)

§  Give adults 1 mg IV push, and repeat every 3–5 minutes.

§  Give children 0.01 mg/kg IV push, and repeat every 3–5 minutes. Remember that subsequent doses are given at 0.1 mg/kg.

f.    If bradycardia is present, administer atropine.

§  Give adults 1 mg IV, and repeat every 3–5 minutes up to a maximum dose of 0.04 mg/kg.

§  Give children 0.02 mg/kg, and repeat only once. Note that the minimum dose of atropine is 0.1 mg, regardless of the weight of the child, because too small a dose of atropine is associated with paroxysmal slowing of the heart.

C. Asystole

§  If the monitor shows asystole (“flatline”), confirm this in another lead. Then:

1.   Intubate and obtain IV access.

2.   If asystole is confirmed, consider immediate transcutaneous pacing.

3.   Administer epinephrine.

§  Give adults 1 mg IV push, and repeat every 3–5 minutes.

§  Give children 0.01 mg/kg IV push, and repeat every 3–5 minutes. Remember that subsequent doses are given at 0.1 mg/kg.

4.   If symptomatic bradycardia is present, administer atropine.

§  Give adults 1 mg IV, and repeat up to a maximum dose of 0.04 mg/kg.

§  Give children 0.02 mg/kg IV (minimum dose=0.1 mg), and repeat up to a maximum dose of 0.04 mg/kg.

5.   If asystole persists, consider termination of efforts.

D. Paroxysmal supraventricular tachycardia (PSVT) [adults]

§  Treatment of PSVT is aimed at interrupting the cycle of impulses traveling to the ventricles to return them to the atrioventricular (AV) node and prevent them from terminating prematurely.

1.   Vagal maneuver

§  is the treatment of choice.

§  slows conduction via the AV node by increasing parasympathetic tone.

§  One of the most common vagal maneuvers is the carotid sinus massage, which is performed by applying firm pressure over the carotid sinus for 5–10 seconds. It is contraindicated in patients with carotid bruits. Simultaneous bilateral carotid sinus massage should never be attempted.

§  Other vagal maneuvers include ice water immersion of the face and performing a Valsalva maneuver.

2.   Pharmacotherapy

§  consists of adenosine and verapamil.

b.   Adenosine

§  is used first because of its fewer side effects and short half-life.

§  is administered via rapid IV push followed by a saline flush.

§  is given up to three consecutive times at doses of 6 mg, 12 mg, and 12–18 mg at intervals of 1–2 minutes.

c.   Verapamil

§  is administered intravenously over 2 minutes in doses of 5 mg (adults) or 075–0.15 mg/kg (children > 2 years of age).

§  Adverse effects include hypotension, which can be managed with 1.5–4.0 mg/kg (adults) or 10–20 mg/kg (children) IV calcium chloride.

d.   Other antiarrhythmics

 

Figure 1-8. Algorithm for treatment of tachycardia. ABCs = airway, breathing, circulation; BPM = beats per minute; ECG = electrocardiogram; IV = intravenous. (Reproduced with permission. Advanced Cardiac Life Support, 1997. Copyright American Heart Association.)

 

Figure 1-9. Electrical cardioversion algorithm. BPM = beats per minute; IV = intravenous; PSVT = paroxysmal supraventricular tachycardia; VT = ventricular tachycardia. (Reproduced with permission. Advanced Cardiac Life Support, 1997. Copyright American Heart Association.)

§  are used if narrow-complex PSVT persists despite adenosine and verapamil.

§  include digoxin, β-blockers, diltiazem, or overdrive pacing.

E. Wide-complex tachycardia

1.   Stable patients (includes VT with a pulse) are treated according to the algorithm shown in Figure 1-8.

2.   Unstable patients with wide-complex tachycardia are treated by cardioversion with premedication, if possible. Figure 1-9 outlines the treatment sequence.

Study Questions

1. A young woman is walking home from work when she passes out on the sidewalk. A crowd of people forms, some of whom attempt to arouse her by talking to her, but she does not respond. A man from the crowd states that he has training in cardiopulmonary resuscitation (CPR) and steps forward to help. Which of the following should be his first step in the management of this patient?

(A) Call for help and then determine whether the patient is breathing and has a pulse

(B) Begin chest compressions and breathing at a rate of 15:2, while waiting for help

(C) Administer 5 back blows followed by 5 quick downward chest thrusts to see if the patient might spontaneously recover

(D) Recruit another person and begin two-person CPR, alternating compressions and breaths at a rate of 15:2

1–A. Because the man does not have training in advanced cardiac life support (ACLS) and does not have access to a defibrillator, basic life support (BLS) techniques must be used. The role of BLS is to sustain the victim until further help arrives. Upon arriving at the scene of an unconscious victim, the first step is to call for help (i.e., ambulance, paramedics, 911). Then the patient's situation (e.g., responsiveness, breathing, pulse) should be assessed. Cardiopulmonary resuscitation (CPR), which is the combination of chest compressions and breaths, should not be started unless the patient is not breathing and does not have a pulse. If a pulse is present, rescue breathing alone may be sufficient. Immediately beginning chest compressions bypasses the initial evaluation of the patient. Administering back blows is inappropriate because back blows are used in infants, not adults. Recruiting another person to help with 2-person CPR alternating compressions and breaths at a rate of 15:2 not only bypasses the initial evaluation, but states the wrong compression:breath rate. The rate of compressions to breaths in two-person CPR is 5:1, not 15:2. Lifting the patient to a standing position is inappropriate because the patient may have sustained cervical spine trauma which could worsen with improper movement.

2. A patient in the coronary care unit is found unconscious. The monitor reveals the rhythm strip below. The crash cart is in the room. Which of the following is the most appropriate first step in the management of this patient?

(A) Administer 0.5 mg of epinephrine intravenous (IV) and check for a pulse

(B) Defibrillate at 200 J and check for pulse

(C) Begin chest compressions at a rate of 80–100/min

(D) Make sure the IV line, oxygen, and monitor are in place

(E) Lift the patient to a standing position and perform a Heimlich maneuver

2–B. The EKG shows ventricular fibrillation (VF). As delineated in the American Heart Association's advanced cardiac life support (ACLS) algorithm, the first step after establishing VF in a patient is to defibrillate, which can immediately restore sinus rhythm. The initial intensity is 200 J, followed by 260 J and then 360 J, if unsuccessful. Checking for the intravenous (IV) line, supplemental oxygen, and cardiac monitor should only be done after defibrillation. Also, because the patient is in the coronary care unit, he probably already has IV access, and he may or may not be intubated. A monitor is obviously in place. Chest compressions are inappropriate before the initial three shocks (defibrillation) are administered. The administration of epinephrine occurs if VF persists after defibrillation and if the IV line, oxygen, and cardiac monitor as necessary are in place. Atropine is administered for bradycardia or asystole. It is not part of the standard algorithm for VF.

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3. Which of the following is true regarding central venous access via the femoral vein?

(A) There is risk of pneumothorax

(B) There is no risk of thrombosis

(C) There is a high incidence of infection

(D) There is great difficulty obtaining access

(E) There is fastest circulation time

3–C. Femoral vein cannulation carries no risk of pneumothorax due to its distance from the lungs. Femoral vein cannulation carries with it the highest risk of thrombosis and infection. Central venous access via the femoral vein often is easier than any of the other approaches, especially in a code situation. Circulation time via femoral vein access is slowest when compared to other approaches.

4. A 52-year-old woman experienced cardiac arrest 5 minutes ago. She has a 2-L O2 nasal cannula and an intravenous (IV) line in place. The electrocardiogram (ECG) shows fine ventricular fibrillation (VF). Femoral, brachial, and carotid pulses are absent. Cardiopulmonary resuscitation (CPR) is being performed by other members of the on-call team. As the code leader, which of the following should be your first step in the management of this patient?

(A) Confirm pulselessness while preparing for immediate defibrillation

(B) Administer 1 mg IV push of epinephrine, then defibrillate

(C) Administer 50 mEq IV bolus of sodium bicarbonate, then defibrillate

(D) Administer both the epinephrine (1 mg IV push) and sodium bicarbonate (50 mEq IV bolus), then defibrillate

(E) Administer 1.0 mg of atropine IV and check for a pulse

4–A. The first priority in the treatment of ventricular fibrillation is immediate defibrillation, because this measure on its own can restore sinus rhythm. Medications are administered only after three consecutive shocks are delivered and fail to restore sinus rhythm. After that, the medication sequence is epinephrine, lidocaine, and bretylium. Sodium bicarbonate is not routinely used for the treatment of VF. Atropine is given for bradycardia.

5. A 47-year-old man is brought to the emergency department by ambulance. The cardiac monitor demonstrates electrical activity, but no pulse is obtainable. As the treatable etiologies of pulseless electrical activity (PEA) are being considered, intravenous (IV) access is confirmed. Which of the following medications should be administered to the patient first?

(A) Calcium chloride, 5 ml of 10% solution IV bolus

(B) Epinephrine, 1 mg IV push

(C) Isoproterenol, 4 mg/min IV infusion

(D) Sodium bicarbonate, 1 mEq/kg IV

(E) Atropine, 1 mg IV push

5–B. Pulseless electrical activity includes electromechanical dissociation, idioventricular rhythms, ventricular escape rhythms, and brady-asystolic rhythms. Once PEA is established, the airway should be secured with intubation. Then IV access is obtained, and blood flow is assessed with Doppler ultrasound, end-tidal CO2, echocardiography, or an arterial line. At this point, causes of PEA are considered so that any treatable causes can be addressed immediately (see V B 1). The first drug administered after this point is epinephrine 1 mg IV push.

6. Which of the following statements regarding endotracheal intubation is true?

(A) It allows adjunctive ventilatory equipment to be used more effectively

(B) It increases the risk of aspiration of gastric contents

(C) It is the immediate priority in ventricular fibrillation (VF)

(D) If done properly, it may result in one lung being inflated

(E) There are few situations in which it is the method of choice

6–A. Endotracheal intubation in place allows adjunctive ventilatory equipment, such as the bag-valve-mask device, to be used more effectively with less effort on the part of the rescuer. Endotracheal intubation decreases, not increases, the risk of aspiration. The immediate priority in ventricular fibrillation (VF) is defibrillation, not endotracheal intubation. If done improperly, endotracheal intubation may result in only a single lung being inflated. It is the method of choice for most situations.

7. A 72-year-old man has been in ventricular fibrillation (VF) for several minutes. The VF is refractory to defibrillation and epinephrine. Which of the following is the correct regimen for the administration of lidocaine?

(A) Lidocaine, 1.0–1.5 mg/kg IV push followed by defibrillation; repeat if necessary in 3–5 minutes to a maximum dose of 3 mg/kg

(B) Lidocaine, 1.0–1.5 mg/kg IV push followed by a pulse check; repeat if necessary in 3–5 minutes to a maximum dose of 3 mg/kg

(C) Lidocaine, 1.0–1.5 mg/kg IV push followed by defibrillation; repeat if necessary in 3–5 minutes at double the dose to a maximum dose of 3 mg/kg

(D) Lidocaine, 1.0–1.5 mg/kg IV push followed by a pulse check; repeat if necessary in 3–5 minutes at double the dose to a maximum dose of 3 mg/kg.

(E) Lidocaine 1.0–1.5 mg/kg IV push followed by defibrillation; repeat if necessary in 3–5 minutes at one half the dose to a maximum does of 3 mg/kg.

7–A. The correct dose of lidocaine when given IV push is 1.0–1.5 mg/kg. Repeat dose is the same dose given after a 3- to 5-minute interval. Treatment of VF with lidocaine is followed by defibrillation, not a pulse check (see universal algorithm, Fig. 1-4). The dose of lidocaine when given via the endotracheal tube is 2–4 mg/kg.

8. Which of the following rapid sequence intubation (RSI) induction agents cannot be used in head trauma?

(A) Thiopental

(B) Methohexital

(C) Ketamine

(D) Etomidate

(E) Midazolam

8–C. Ketamine is contraindicated in the setting of head trauma, as it increases intracranial pressure (ICP). Thiopental, methohexital, etomidate, and midazolam are all safe for use in patients with increased ICP.

9. Although succinylcholine is the choice depolarizing neuromuscular blocking agent in rapid sequence intubation (RSI), it should be avoided in which of the following situations?

Narrow-angle glaucoma

Cataracts

Altered mental status

Hypokalemia

Hypernatremia

9–A. Succinylcholine (SCh) is associated with a number of side effects, including hyperkalemia, malignant hyperthermia, prolonged apnea, histamine release, and muscle fasciculations. Muscle fasciculations in turn result in an increase in intragastric and intraocular pressure (IOP). The rise in IOP would exacerbate the already elevated IOP in narrow-angle glaucoma and is therefore contraindicated in this situation. However, complications from muscle fasciculations can be overcome by the administration of a prefasciculating dose of a competitive neuromuscular blocker such as vecuronium. The presence of cataracts or hypernatremia does not influence SCh use. Altered mental status is one of the indications for using RSI and SCh. Hyperkalemia would be a contraindication to SCh use, but hypokalemia is not. See Table 1-2.

Directions: The response options for Items 10–13 are the same. You will be required to select one answer for each item in the set.

Questions 10–13

Match each drug listed below with the correct description.

A.  Epinephrine

B.   Procainamide

C.  Atropine

D.  Magnesium

10. The first drug used in the treatment of ventricular fibrillation

10–A. The treatment of ventricular fibrillation can be summarized by the following mnemonic: Shock, shock, shock, everybody shock, little shock, big shock, mama shock, papa shock.

Shock, shock, shock: defibrillate x 3: at 200 J, 300 J, and 360 J in adults and at 2 J/kg, 4J/kg, and 4 J/kg in children

Everybody shock: Epinephrine 1 mg/kg IV

Little shock: Lidocaine 1.0–1.5 mg/kg IV

Big shock: Bretylium 5 mg/kg IV, can repeat once at 10 mg/kg

Mama shock: Magnesium 1–2 g IV

Papa shock: Procainamide 20–30 mg/min (max. dose is 17 mg/kg)

11. Drug of choice for torsades de pointes

11–D. Magnesium sulfate is the drug of choice for the treatment of torsades de pointes. The optimum dosage has not been established. Generally, treatment begins with 1–2 g IV push, watching for hypotension. Dosages of up to 10 g have been used. Torsades de pointes is a type of polymorphic ventricular tachycardia characterized by a ventricular rate greater than 200/min and a spiraling of the QRS complexes. It often is the result of underlying electrolyte imbalances such as hypomagnesemia.

12. Drug of choice for symptomatic bradycardia

12–C. Atropine is the drug of choice for symptomatic bradycardia and brady-asystolic cardiac arrest. The dose for symptomatic bradycardia is 0.5–1.0 mg, which may be repeated at 5-minute intervals. Consider a pacemaker for patients who require prolonged atropine or with recurrent episodes of bradycardia. The dose for brady-asystolic cardiac arrest (asystole) is 1 mg IV repeated every 3–5 minutes as needed. The maximum dose of atropine in both settings is 0.04 mg/kg. Note that the minimum dose of atropine is 0.1 mg regardless of the patient's weight, because a smaller dose can actually produce paroxysmal bradycardia.

13. Drug used for persistent refractory ventricular fibrillation

13–B. As per the American Heart Association, procainamide is used for persistent ventricular fibrillation that is refractory to epinephrine, lidocaine, and bretylium. The dose is 20–30 mg/min until the arrhythmia is suppressed. This rate may not produce an effective dose fast enough, but a rate faster than this produces profound hypotension. Therefore, the drug is not widely used in code situations. Treatment with procainamide must be stopped when the QRS complex is widened by 50% or more, or the PR or QT interval is lengthened by 50% or more. Heart block and cardiac arrest are potential complications. Procainamide is relatively contraindicated in the presence of hypokalemia and hypomagnesemia because it can potentiate ventricular arrhythmias in these situations.

Directions: The response options for Items 14–16 are the same. Each item will state the number of options to choose. Choose exactly this number.

Questions 14–16

Match each statement below with the appropriate drugs.

A.  Adenosine

B.   Lidocaine

C.  Thiopental

D.  Verapamil

E.   Etomidate

F.   Epinephrine

G.  Diltiazem

H.  Midazolam

I.    Propranolol

J.   Bretylium

14. Induction agents used for patients with head trauma (select 3 drugs)

14–C, E, F. See Table 1-1 for a listing of common induction agents. Thiopental, etomidate, and midazolam are good for patients with head injury because they do not increase the intracranial pressure (ICP). Fentanyl and diazepam also are good choices. Ketamine, on the other hand, is contraindicated in this setting because it does raise ICP.

15. Drugs used in the treatment of paroxysmal supraventricular tachycardia (select 4 drugs)

15–A, D, G, I. Adenosine is the first drug of choice (after vagal maneuvers) for the treatment of non-wide-complex (narrow-complex) PSVT. The dose is 6 mg rapid IV push followed by a saline flush, because the half-life of the drug is only 10 seconds. Repeat doses of 12 mg and 12–18 mg are given at 1- to 2-minute intervals. Patients should be warned about a possible distressing but fleeting chest pain and flushing as the drug goes in. Because of the short half-life of the drug, the PSVT may recur, and one may consider verapamil or diltiazem, which are longer-acting. Verapamil and diltiazem block slow calcium channels, resulting in potent negative inotropic (verapamil) and negative chronotropic (verapamil and diltiazem) activity. These effects are useful in terminating supraventricular tachycardias that re-enter via the AV node (the most common type). Verapamil and diltiazem are indicated in the treatment of PSVT that does not require cardioversion (i.e., patient is hemodynamically stable). The dose of verapamil is 1.5–5 mg slow IV push, which may be repeated in 15–30 minutes. The dose of diltiazem is 0.25 mg/kg slow IV push. Watch for hypotension with these drugs. Adenosine, verapamil, and diltiazem are considered first-line therapies for PSVT. If these fail, then many other therapies are acceptable if judged to be clinically useful. These include β-blockers (such as propranolol), digoxin, sedation, overdrive pacing, and electrical cardioversion.

16. Drugs used in the treatment of ventricular fibrillation (select 3 drugs)

16–B, F, J. See explanation for Question 10.