PALS: Year 2000 Guidelines Analysis

This report is based on final published PALS changes reported in 
Circulation Supplement for August 22, 2000. All readers are 
encouraged to read the findings for themselves-this review is not 
meant to be comprehensive nor should it substitute for an PALS 
provider's own inquiry into these subjects, issues and 
recommendations. This material in Circulation represents a process 
of intensive review and consensus begun well over 18 months ago. 
A "roll out" is scheduled for September 21-24 in San Diego where 
this information will be further explained and how it will be 
incorporated in future PALS will be presented. This, then represents 
the content that the San Diego conference will be based upon..

Chris Perrin, ACUTE CARE, INC. Director of Education

SEE ALSO: PBLS (Pediatric Basic Life Support)
Ethical Aspects of CPR and ECC,
Adult BLS (Basic Life Support),
and ACLS (Advanced Cardiac Life Support)

New!

Added (10/4/01) From Contemporary Pediatrics: New guidelines for pediatric life support
Nice overview!

The AHA Instructor's Corner lists "end of June, 2001"
for date of availability for PALS teaching materials.

Link to Template for PALS Class
This is the draft template for the PALS Provider class schedule
PALS Textbook

and

Additional PALS Material from the Instructor Rollout, and
Agenda and Equipment for the PALS Rollout

CONTENTS

Definitions of Classes

PALS

Major Changes

Introduction

Adjuncts for Airway and Ventilation

Establishing and Maintaining Venous Access

Drugs Used for Cardiac Arrest Resuscitation

Rhythm Disturbances

Defibrillation, Cardioversion, and External Pacing

PALS for the Pediatric Trauma Victim

Special Resuscitation Situations

Post Resuscitation Stabilization 

Family Presence During Resuscitation

Termination of Resuscitative Efforts

NEONATAL

Major Changes

Resuscitation with Lower Oxygen Concentrations

LMA's

Chest Compressions

Epinephrine

Discontinuation of Resuscitative Efforts

Throughout the Guidelines, the following definitions of classes of recommendations are used:

• Class I recommendations are always acceptable. They are proven 
  safe and definitely useful, and they are supported by excellent 
  evidence from at least one prospective, randomized controlled 
  clinical trial
• Class IIa recommendations are considered acceptable and useful 
  with good to very good evidence providing support. The weight of 
  evidence and expert opinions strongly favor these interventions.
• Class IIb recommendations are considered acceptable and useful with 
  weak or only fair evidence providing support. The weight of evidence 
  and expert opinion are not strongly in favor of the intervention.
• Class III refers to interventions that are unacceptable. These 
  interventions lack any evidence of benefit, and often the evidence 
  suggests or confirms harm.
• Class Indeterminate refers to an intervention that is promising, but 
  the evidence is insufficient in quantity and/or quality to support a 
  definitive class of recommendation. The Indeterminate Class was 
  added to indicate interventions that are considered safe and perhaps 
  effective and are recommended by expert consensus. However, the 
  available evidence supporting the recommendation is either too weak 
  or too limited at present to make a definitive recommendation based 
  on the published data.

PALS: Major Changes

Adoption of International Terminology

• Tracheal tube instead of endotracheal tube
• Manual resuscitator instead of bag-valve mask
• Exhaled CO₂ detection instead of end-tidal CO₂ detection
• Defibrillation clarified. “Shocks are administered to victims in an attempt to achieve defibrillation.”

Ventilation 

• Discussion of endotracheal intubation vs. laryngeal mask airway vs. manual resuscitator, with an emphasis on intubation and the contention that sufficient skill and experience need to be present to warrant using this technique with children. Skill with the manual resuscitator is mandatory for anyone providing ALS for children and infants.

Fluid Therapy 

• Suggests the use of intraosseous infusions for children (and adults) older than 6 years old.

Medications 

• New information on determining and treating the cause of arrest, with considerable material on toxic drug overdose and metabolic derangements.

• While high dose epinephrine and vasopressin are discussed, data is insufficient to allow firm recommendation for their use with children (Class Indeterminate)

Treatment of Arrhythmias 

• Vagal maneuvers are introduced in the SVT discussion
• Amiodarone is offered as a new treatment for pediatric VT and shock-refractory VF
• AEDs may be used for children older than 8 years of age (approximately 25 kg)

Postarrest Stabilization 

• Emphasis on normal ventilation rather than hyperventilation
• Control of temperature, management of postischemic myocardial dysfunction and glucose control

Introduction

"Bystander CPR is provided for only 30% of out-of-hospital pediatric arrests."

• Bag-valve-mask ventilation (ventilation bag) is the primary method of ventilatory support for prehospital BLS care, particularly if the transport time is short.
• Intubation of pediatric patients in the out-of-hospital setting requires adequate initial training, ongoing experience, and outcome monitoring.
• While the LMA (laryngeal mask airway) is a proven, effective adjunct for pediatric ventilation, there are two concerns noted in the Guidelines: "An LMA may be more difficult to maintain during patient transport than a tracheal tube." "Furthermore, the LMA is relatively expensive, and a number of sizes are needed…The cost of equipping out-of hospital providers must be considered."
• Neonatal (250 ml) ventilation bags should not be used in ventilation of full-term neonates and infants. Using only the force necessary to cause the chest to visibly rise, ventilation bags with a minimum volume of 450-500 ml are preferred.
• "E-C clamp" technique for opening the airway and sealing the mask to the face introduced for ventilation bag performance: "The third, fourth and fifth fingers (forming an E) are positioned to lift it forward; then the thumb and index finger (forming a C) hold the mask on the child’s face."
•  Uncuffed tracheal tubes recommended for children younger than 8 years old. Rationale: obstruction to passage of the tube may occur at a point just below the glottic opening.
•  A formula for determining tracheal tube size: Size (mm) = (age in yrs / 4) + 4, if cuffed , add 3 instead of 4. For tracheal tubes, length-based resuscitation tapes are accurate for children to approximately 35 kg
• Preparing for endotracheal intubation, assemble three tracheal tubes: the tube of estimated size, one 0.5 mm larger and one 0.5 mm smaller
• Interrupt intubation attempts “if bradycardia develops, the child’s color or perfusion deteriorates, or the oxygen saturation by pulse oximetry falls to an unacceptable level”
•  When intubating, use a small pillow to achieve “sniffing” position (slight flexion) for children older than 2 years of age. For younger children (<2) and infants, a pillow is not used. Rather, a small roll is often used to elevate the shoulders.
• Two formulas to estimate appropriate depth of insertion for the tracheal tube: Depth of insertion (cm) = internal diameter (mm) x 3. Alternative (for children older than 2): Depth of insertion (cm) = (age in yrs/2) + 12

• Regarding exhaled or end-tidal CO₂ monitoring: “Six ventilations are recommended to wash out CO₂ that may be present in the stomach and esophagus after bag-valve-mask ventilation. After 6 ventilations, detected CO₂ can be presumed to be from the trachea rather than from a misplaced tube in the esophagus.”

•  Also regarding exhaled or end-tidal CO₂ monitoring: Detection of exhaled CO₂ in patients with a perfusing rhythm is both specific and sensitive for tube placement in the trachea (Class IIa), exhaled CO₂ detection is not as useful for patients in cardiac arrest (Class Indeterminate).

• Emphasis on multi-factor confirmation of tracheal tube placement and continuous efforts to ensure preservation of that correct placement.

Establishing and Maintaining Venous Access

• While the preferred site for intraosseous access in children is the proximal anterior tibia, the Guidelines mention the alternative sites of the distal femur, medial malleolus and anterior superior iliac spine. It also takes note that “In older children and adults intraosseous cannulas were successfully inserted into the radius and ulna in addition to the proximal tibia.”
• The Guidelines refine instructions for endotracheal instillation of medications: dilution of the drug with up to 5 ml of normal saline followed by 5 ventilations is equivalent to, and preferred over, delivery of the drug through a catheter or feeding tube threaded though the endotracheal tube.

Drugs Used for Cardiac Arrest Resuscitation 

• Vasopressin is a Class Indeterminate action. While data supports its use in adult shock-refractory VF, there is inadequate data supporting its use in infants and children.
• “Ionized hypocalcemia is relatively common in critically ill children, particularly those with sepsis.” Accordingly, calcium chloride 10% is discussed. It is preferred over calcium gluconate because of the greater “bioavailability of calcium.”
• Evaluation for hypoglycemia is again addressed, with treatment using 25% glucose and / or 10% glucose boluses. The Guidelines state, however, that hypoglycemia should be treated with continuous infusions when possible, as bolus therapy can cause osmotic diuresis.
• The discussion of sodium bicarbonate is interesting for the notation that while the “dilute solution (4.2%, 0.5 mEq/ml) may be used in neonates to limit the osmotic load, but there is no evidence that the dilute solution is beneficial for older infants and children.”

Rhythm Disturbances 

·         The Guidelines note that, while the rhythm most commonly recorded in pediatric cardiac arrest is asystole or a bradyarrhythmia, approximately 10% of these patients had VF or pulseless VT. This number might be as large as 20% when SIDS patients are excluded. It appears that children older than 9 years of age had significantly more VF than those under 4.

·         There are four algorithms in the PALS Guidelines:

§         Pulseless Arrest (which combines VF, pulseless VT, PEA and asystole),

§         Bradycardia,

§         “Tachycardia for infants and children with rapid rhythm and adequate perfusion”, and

§         “Tachycardia for infants and children with rapid rhythm and evidence of poor perfusion”

·         While epinephrine remains the first choice of medication for the treatment of symptomatic pediatric bradycardia, atropine (0.02 mg/kg) is offered as the preferred medication for bradycardia caused by increased vagal tone.

·         Symptomatic bradycardia, as detailed in the algorithm: “poor perfusion, hypotension, respiratory difficulty, altered consciousness”

·         While transthoracic pacing has not been proven effective for pediatric asystole or bradycardia secondary to postarrest hypoxia / ischemia or respiratory failure, the Guidelines note that pacing “may be lifesaving” for “selected cases of bradycardia caused by complete heart block or abnormal function of the sinus node.”

·          The bradycardia algorithm includes the performance of chest compressions for bradycardia causing severe cardiorespiratory compromise (see “symptomatic bradycardia”, above) if, despite oxygenation and ventilation, the infant or child’s heart rate is less than 60 and the infant or child shows evidence of poor systemic perfusion.

·         Each of the four algorithms emphasizes “Identify and Treat Possible Causes”. Pulseless Arrest and both Tachycardia algorithms use “The 4 H’s and 4 T’s”:

§         Hypovolemia

§         Hypoxemia

§         Hypothermia

§         Hyperkalemia (and other metabolic disturbances)

§         Tension Pneumothorax

§         Pericardial Tamponade

§         Toxins

§         Thromboembolus

·         “Supraventricular tachycardia (SVT) is the most common nonarrest arrhythmia during childhood and is the most common arrythmia that produces cardiovascular instability.”

·         The Guidelines note that while P waves are difficult to identify in childhood tachycardia, P waves in sinus tachycardia will be upright in leads I and aVF, while P waves in SVT will be negative in leads II, III, and aVF.

·         Vagal maneuvers are introduced as a Class IIa action for the treatment of SVT. Ice water applied to the face for infants and young children is described, as is having the child blow through a straw for a Valsalva maneuver. External ocular pressure is specifically excluded.

·         “When medications are indicated, adenosine is the drug of choice for SVT in children.” The “two-syringe technique” is described and recommended, with one syringe containing adenosine and the other containing 5-ml of normal saline.

·         Verapamil for SVT is Class III for infants (refractory hypotension and cardiac arrest), and its use is discouraged in children (hypotension and myocardial depression.

·         The use of Amiodarone in children is introduced. The drug is a Class IIb action for VT with a pulse and a Class Indeterminate for VF and pulseless VT. Use of the drug in shock-refractory VF and pulseless VT follows three shocks, epinephrine and a fourth shock. The recommended dose is 5 mg/kg, rapid IV bolus. For SVT, this same dose (5 mg/kg) is recommended as a loading dose given IV,  “over several minutes to 1 hour”. Repeated doses of 5 mg/kg, to a maximum of 15 mg/kg/day can be given.

·         Lidocaine’s use in VT/VF is now Class Indeterminate. “Although lidocaine has long been recommended for treatment of ventricular arrhythmias in infants and children, data suggests it is not very effective unless the arrhythmia is associated with myocardial ischemia.”

·         Procainamide is no longer recommended for use in childhood VF and pulseless VT, by virtue of the requirement for administration by slow infusion. Its use in perfusing rhythms, including VT with a pulse, can be considered as a Class IIb action: 15 mg/kg over 30 to 60 minutes, with continuous monitoring of ECG and BP.  

·         The use of vasopressin and high dose epinephrine is addressed  briefly as a “vasoconstrictor regimen.” “ …high dose (0.1-0.2 mg/kg) may be considered in shock-resistant VF/pulseless VT (Class IIb)..”  Promising adult data places vasopressin as a Class Indeterminate agent for the same rhythms.

Defibrillation, Cardioversion, and External Pacing

• Biphasic AED's are acceptable (Class Indeterminate) for use for children over 8 years of age, though there is a need for additional data to support this use. Additional AED recommendations include:

  • Regarding adult defibrillation settings in the out-of-hospital setting: "may be reasonable" for children older than 8 years of age, "certainly reasonable" for children who weigh at least 50 kg

  • AED's may be considered for rhythm identification in children older than 8 years of age

• While the three shock, then drug-shock, drug-shock regimen continues for VF and pulseless VT, an alternative is described: 

  • Three shocks

  • Intubation, IV and drug administration, CPR

  • Three additional shocks, in succession

• Regarding noninvasive (transcutaneous) pacing: 

  • Not recommended for cardiac arrest (asystole)

  • Class IIb for "profound symptomatic bradycardia refractory to BLS and ALS"

  • If the child weighs less than 15 kg, pediatric (small or medium) electrodes should be used. "In general, if smaller electrodes are used, the pacer output required to produce capture will be higher."

PALS for the Pediatric Trauma Victim

• Regarding intubation in the traumatized victim: "We particularly encourage confirmation of proper tracheal tube placement by use of capnography or exhaled CO2 detection both after intubation and throughout transport (Class IIa)..."

• Hyperventilation of pediatric head trauma patients is no longer routinely recommended (Class III)

• The E aspect of ABCDE Primary Survey "involves maintenance of a neutral thermal environment - keeping the child warm". It also means "completely examine the child for hidden injuries."

Special Resuscitation Situations

• The Guidelines include an extensive and detailed section on Toxicological Emergencies, including:

  • Cocaine

  • Tricyclic Antidepressants and Other Sodium Channel Blockers

  • Calcium Channel Blocker Toxicity

  • Beta-Adrenergic Blocker Toxicity

  • Opioid Toxicity

Post Resuscitation Stabilization 

The Neurological Preservation section includes the following information about hyperthermia and active cooling:

• While "recent data suggests that postarrest or postischemia hypothermia (core temperatures 33 to 36 degrees Centigrade) may have beneficial effects on neurological function." "There is insufficient data, however, to recommend the routine application of hypothermia (Class Indeterminate)

• However - Postarrest patients with core temperatures greater than 33 degrees Centigrade and less than 37.5 degrees Centigrade should not be actively rewarmed.

• Postarrest patients with core temperatures lower than 33 degrees Centigrade should only be rewarmed to 34 degrees

• "In the brain-injured patient or in the postarrest patient with compromised cardiac output, correct hyperthermia to achieve a normal core temperature (Class IIa)

Family Presence During Resuscitation

The Guidelines offer multiple studies that promote and explain the validity of family presence during resuscitative efforts. 

Termination of Resuscitative Efforts

"If a child fails to respond to at least 2 doses of epinephrine with a return of spontaneous circulation, the child is unlikely to survive. In the absence of recurring or refractory VF or VT, history of a toxic drug exposure, or a primary hypothermic insult, resuscitative efforts may be discontinued if there is no return of spontaneous circulation despite ALS interventions. In general, this requires no more than 30 minutes."

Neonatal Resuscitation

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