Anti-Shivering Protocols

Therapeutic temperature modulation involves cooling the body temperature to a set goal (mostly 32-34C) to improve the outcome of patients who have suffered cardiopulmonary arrest. One of the common adverse effects of this therapy is shivering.  This blog summarizes the anti-shivering protocol that is used at the Neurological Institute of New York, Columbia University College of Physicians and Surgeons, as published in 2011.

Table. The Columbia Anti-Shivering Protocol.Shivering Protocol*Mnemonic:  AMBS-DO-DO-Pro-Vec

 Technique:

  1. Use Bedside Shivering Assessment Scale (BSAS Score) with a goal to achieve no to minimal shivering (BSAS </=1)
  2. (Step 0) start AMBS, continued throughout entire cooling period
  3. (Step 1) add opiate or dexmedetomidine if goal not reached
    1. consider opiates if poorly controlled pain or bradycardic
    2. consider dexmedetomidine if uncontrolled agitation
  4. (Step 2) combine dexmedetomidine and opiate
  5. (Step 3) add deep sedation with propofol (50–75 mcg/kg/min) [*only increases in the initial dose of propofol or high levels of propofol considered as shivering interventions]
  6. (Step 4) Neuromuscular blockade with boluses of a paralytic – prefer vecuronium (0.15 mg/kg IV bolus)

 

NSUH Shivering Algorithm

Prior to TTM:

  1. apply BAIR hugger surface warmer at max temperature of 42C
  2. Buspirone 30mg PO /NGT q8h
  3. Acetaminophen 650mg PR/PO/NGT q4h standing

Start TTM – hourly BSAS

Step 1 (if BSAS >1):

  1. Dexmedetomidine 0.3 ug/Kg/hr, titrate by 1.5 ug/Kg/hr
  2. Magnesium sulfate 4g IV bolus then 1g/hr to reach serum Mg 3.0-4.0
  3. Serum Mg levels q8h

Step 2 (if BSAS >1):

  • Add propofol at 20 ug/Kg/min, titrate to max 50 ug/Kg/min

Step 3 (if BSAS >1):

  • Fentanyl 50-150 ug bolus, then 75 ug/hr

Step 4 (if BSAS >1):

  • d/c TTM or add cisatracurium drip or intermittent vecuronium boluses

 

Table. The Bedside Shivering Assessment Scale:

BSAS

BSAS (NSUH)

  • 0 = no shivering (neither visually nor with palpation of thorax)
  • 1 = MILD (localized to neck and/or thorax only)
  • 2= MODERATE (intermittent involvement of UE/LE or continuous involvement of UE)
  • 3 = SEVERE (intermittent or continous total body involvement including UE and/or LE and thorax)

 

A study showed:

  • 18% of patients required only step 0 interventions
  • 29% received 1 agent
  • 35% received 2 agents
  • 15% received 3 agents
  • 2.4 received 4 agents

 

Factors in predicting number of anti-shivering interventions used:

  1. age
  2. gender
  3. BSA

Young men with lower BSA scores were more likely to require more interventions for shivering (due to greater muscle mass.)

Also, lower GCS = decreased ability to modulate core body temperature, so shivering response is dampened.

Mechanisms of Action:

  1. Counterwarming.  Mean skin temperature ~20% input to hypothalamus about body temperature
  2. Acetaminophen – inhibits cyclooxygenase-mediated prostaglandin synthesis to lower the hypothalamic set point
  3. Buspirone – acts on 5-HT1A receptor to lower the shivering threshold
  4. Magnesium sulfate infusion (shown to increase comfort and decrease time to goal temperature) – cause peripheral vasodilation
  5. Dexmeditomidine – central alpha-2 receptor agonist with anti-shivering properties on vasoconstriction and shivering thresholds
    1. side effect: bradycardia, hypotension
    2. advantage: lack of respiratory depression
  6. Opiates – μ- and κ-opioid receptor agonists impair thermoregulatory control
    1. Meperidine – affect alpha 2B adrenoceptor subtype, lowers seizure threshold
    2. Fentanyl – less selective anti-shivering properties, primary mechanism of shiver due to sedative impact on brain-injured patients
  7. Propofol – mildly reduces vasoconstriction and shivering thresholds
    1. Side effects: hypotension, negative cardiac ionotropy, sedation, and propofol infusion syndrome
  8. Paralytics
    1. Side effects:  loss of neurologic exam, weakness associated with critical illness
    2. needs adequate sedation
    3. advantage: quickest method of ceasing the shivering response

Other Interventions to Decrease Shivering

  1. Dantrolene – decrease shivering by peripheral actions on muscle by reducing gain
  2. Ketamine and Ondansetron – lowers shivering threshold

 

Dosages (Uptodate):

Meperidine:  Postoperative shivering (off-label use): IV: 25 to 50 mg once (limit to ≤48 hours, doses should not exceed 600 mg/24 hours)

Vecuronium:  Control of refractory shivering in adequately sedated patients during therapeutic hypothermia after cardiac arrest (off-label use): IV: 8-12 mg; redose as needed to control shivering. Note: Duration of action prolonged in hypothermic patients. May mask seizure activity.

 

Another Anti-Shiver algorithm:

40560_2016_141_Fig1_HTML

*PT = per NG tube.

 

References

[1] Choi, H. Alex et al. ‘Prevention Of Shivering During Therapeutic Temperature Modulation: The Columbia Anti-Shivering Protocol’. Neurocritical Care 14.3 (2011): 389-394.

[2] Presciutti, M., M. K. Bader, and M. Hepburn. ‘Shivering Management During Therapeutic Temperature Modulation: Nurses’ Perspective’. Critical Care Nurse 32.1 (2012): 33-42. Web.

[3] Uptodate.com, ‘Vecuronium’ and ‘Meperidine,’ accessed 12/06/2015.

[4] NSUH Shivering Protocol.

[5] Kuroda, Yasuhiro. “Neurocritical Care Update”. Journal of Intensive Care 4.1 (2016): n. pag.

Advertisements

Tagged: , , , , , ,

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: