Sedation
Stanford PICU Sedation Protocol v2.0- Continuous Sedation (see below for intermittent)
Intermittent Sedation Protocol v1.0
FLACC and SBSS Scoring
Sedation Meds and Mechanisms (Courtesy of Richard Pierce, MD)
General Approach
Most patients admitted to the PICU with needs for general sedation on mechanical ventilation:
Step 1: Fentanyl (1 mcg/kg/hr) and Dexmedetomidine (0.3 mcg/kg/hr titrated up to max of about 1.5 mcg/kr/hr) to start with q1hr PRNs of fentanyl
Step 2: Add midazolam(20 mcg/kg/hr titrated up to max of about 300 mcg/kg/hr) if additional sedation needed
Step 3: Consider transition to morphine or hydromorphone if on fentanyl >5 days as tachyphylaxis can develop to fentanyl and morphine is naturally more sedating. Morphine may not be ideal in a patient with an asthma exacerbation or extremely tenuous hemodynamics due to histamine release.
Step 4: Consider transition from midazolam to lorazepam
Step 5: Consider additional adjuvant agents (i.e. chloral hydrate, PRN ketamine, benadryl, some might use gabapentin for neuropathic pain)
Step 6: Consider adding neuromuscular blocking agent as an adjuvant (titrated to weaken a patient generally well sedated but occasional movements threaten tubes/devices/therapeutics)
Step 7: Consider brief propofol wash out (12 hours) to "reset" body's receptors and decrease doses needed
Step 8: Consider pentobarbital infusion with PRN's recognizing long half life, potential for hemodynamic compromise
Special circumstances:
Status asthmaticus: Ketamine (for sedation + bronchodilation)
Need for quick on/off (i.e. for neuro exam): Propofol or trial of using PRN's of fentanyl/midazolam only
Brief, painful procedure while maintaining spontaneous respirations: local anesthetic +: ketamine PRN's vs. dexmedetomidine infusion + fentanyl PRN vs. low dose propofol infusion + propofol boluses
Take the edge off while maintaining spontaneous respirations (i.e. younger patient who is anxious about noninvasive positive pressure ventilation): dexmedetomidine
Propofol Washout:
Using propofol as a single agent, one can turn off the rest of the infusions (recognizing propofol does not have analgesic properties), allowing the other drugs (benzodiazepenes and narcotics typically) to "wash out." This allows you to shut off the propofol and the patient should wake fairly readily, rather than waiting for a much longer and indeterminate amount of time for the child to wake up as the drug levels slowly decrease
In addition, propofol wash outs can be used as a bridge to decrease narcotic/benzodiazepene dosage requirements by theoretically desaturating the receptors and and thus increasing their overall efficacy.
In children, we are limited to 12 hours due to the risk of propofol infusion syndrome which is dose and duration dependent and more commonly occurs in children. This is due to mitochondrial toxicity which results in lactic acidosis and can result in profound cardiovascular collapse and death. Green urine can also be seen due to a metabolite of propofol although this does not necessarily increase the risk of propofol infusion syndrome
Methadone and Valium
These are used as medications to prevent withdrawal. The approximate risk of withdrawal is ~50% after 5 days worth of sedative infusions but is again, dose and duration dependent.
Often these are started at 0.1 mg/kg IV q6 each a few days before extubation to allow for the drugs to reach steady state. They can also be started as an additional sedative agent if one is already utilizing high dose narcotic or benzodiazepene infusions.
Methadone IV:PO conversion is generally about 1:1.4-2 (ie PO is about half as potent) while diazpeam IV:PO is 1:1.
Weans generally occur over about 10 days (or roughly 1-1.5 x the duration of the infusions in days) with 10% weans of the total dose of one medication each day alternating. This is adjusted based on withdrawal assessment tool (WAT) scoring with scores >4 suggesting some withdrawal (higher scores indicate more withdrawal)
Neuromuscular Blockade
Generally use vecuronium or ciastracurium infusions to chemically paralyze ("muscle relax") patients.
Can serve to reduce metabolic demand in cases where oxygen delivery is impaired, reduce shivering, improve ventilator patient synchrony (ie with HFOV), or as an adjuvant agent in a patient who is generally well sedated but an intermittent threat to vital lines and tubes
Cisatracurium is often used as the infusion of choice given its elimination occurs via Hoffman degradation (pH and temperature dependent) rather than being dependent upon renal (ie rocuronium) or hepatic function (ie vecuronium)
Train of four monitoring is essential for patients who are not moving to ensure that they are not being overly blocked, which can lead to polyneuropathy and iatrogenic muscle weakness/atrophy. We generally aim for 2 twitches out of four.
PCA Dosing and Respiratory Effects, Courtesy of Richard Pierce, MD
General Considerations:
1) What is the overall goal? (i.e. pain control?, amnesia to procedure?, etc.)
2) What is the medical condition of the patient? (i.e. co-morbidities?)
3) How quickly do you want the desired effect? [most relevant when considering intubation]
4) What is the duration of the desired effect?
5) What are the potential side effects, and are they unacceptable in that particular setting?
6) How is the medication metabolized/cleared, and is this important?
7) Is the route of delivery important?
8) Are there cost considerations?
Sedation and NMB, courtesy of Kato Han, MD
Neuromuscular Blockers:
Neuromuscular Blockers not on Formulary:
Analgesics:
Analgesics (cont.):
Sedatives/Hypnotics/Anesthetics:
Cases:
1) 9 month old infant with jaundice and liver failure requiring percutaneous liver biopsy.
2) Same patient 2 hours later, tachycardic, appearing pale and mottled.
3) Same patient 24 hours later, on HFOV for ARDS, requiring epinephrine infusion, no urine for past 8 hours.
4) 10 year old s/p MVA, initially following commands but now becoming unresponsive after arrival into the trauma room.
5) 6 year old initially admitted for septic shock/ARDS/MODS, continuing to require moderate amounts of support and increasing sedative doses for “agitation”; seems somewhat “wild” at times.
Sedation Chart, Sedation Chart 2
Evidence
RESTORE by Curley et al demonstrated no difference in length of mechanical ventilation when utilizing a protocol for sedation vs. usual care in pediatric patients with acute respiratory failure
Withdrawal
Generally consider WAT-1 score >4 consistent with withdrawal
Risk of withdrawal related to cumulative dose and duration of opioid and benzodiazepene exposure
Often start methadone/valium if patient has been on moderate/high dose benzodiazepenes and narcotics for 5+ days
References
1) Curley MA, Wypij D, Watson RS, Grant MJ, Asaro LA, Cheifetz IM, Dodson BL,Franck LS, Gedeit RG, Angus DC, Matthay MA; RESTORE Study Investigators and the
Pediatric Acute Lung Injury and Sepsis Investigators Network. Protocolized sedation vs usual care in pediatric patients mechanically ventilated for acute
respiratory failure: a randomized clinical trial. JAMA. 2015 Jan 27;313(4):379-89. doi: 10.1001/jama.2014.18399. PubMed PMID: 25602358.
2) Franck LS, Harris SK, Soetenga DJ, Amling JK, Curley MA. The Withdrawal Assessment Tool-1 (WAT-1): an assessment instrument for monitoring opioid andbenzodiazepine withdrawal symptoms in pediatric patients. Pediatr Crit Care Med. 2008 Nov;9(6):573-80.
3) Adult CPG for Pain, Sedation, Delirium, Mobility, CCM 2018