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Anesthesia Issues
Propofol for pediatric procedural sedation reducing the pain on propofol injection laryngospasm
February 7, 2002Sarah McPherson
Pediatric procedural sedation
“ The goal of procedural sedation is the safe and effective control of pain, anxiety, and motion so as to allow a necessary procedure to be performed and to provide an appropriate degree of memory loss or decreased awareness.”
NEJM.2000;342(12):938-945
What is the current status?
Most peds sedation is with Ketamine or Midazolam + a narcotic NEJM.2000;342(12):938-45
adverse effects including: oxygen desaturation, apnea, stridor, laryngospasm, bronchospasm, cardiovascular instability, emesis, aspiration, emergence reactions, and paradoxical reactions occur in approximately 2.3% of casesAnn Emerg Med.1999;34(4):483-91
Why the concerns about propofol?
Concerns of upper airway obstruction 10 children aged 2-10 deep sedation with propofol but none were intubated MRI to visualize glottic structures during sedation preserve upper airway at all measured sites
Anesth.1999;90(6):1617-23
More concerns
Hypoxiahypotensionapnealaryngospasm
overshooting depth of anesthesia
Propofol infusion syndrome
Reported in 18 childrenchildren admitted to ICU sedated with high doses of propofol
for > 48 hrprogressive myocardial failure and
deathPaed Anasth.1998;8(6):491-9
Lactic acidemia and bradyarrhythmias
Refractory acidemia, bradycardia, hypotension, lipemia and oliguria
reported in 11 children after propofol infusion in the ICU
direct link to propofol not proven
no case reports with one time useCrit Care Med.1998;26(12):1959-60
Propofol in the OR
Safety documented in surgical, opthamologic, urologic and dental procedures
Gastro Endo.2002;55(1)
routinely used at ACH for induction of anesthesia
What about procedural sedation?
In the ICU prospective study N = 50 sedation with intermittent boluses of propofol preprocedure fasting 68% systolic hypotension, 30% requiring iv fluid 4% hypoxia 12% partial upper airway obstruction 2% apnea no children require oral airways start to recovery time = 23 min
Pediatrics.2000;106(4):742-7
In the ICU
Retrospective, N = 52 children, 335 procedures
oncology patients propofol, propofol + fentanyl, propofol +
midaz6 episodes of hypoxia1 episode of laryngospasm
J Ped Hem Onc.2001;23(5):290-3
In the ICU
Retrospective, N = 64pre procedure fastinganalgesia and sedation with either ketamine +
midaz iv, Propofol and fentanyl iv, ketamine + midaz po
length of anesthesia time 17 min (range 10-50 min)in propofol group, 37 min (range 10 - 150min)
no respiratory depression, hypotension, or emesis in fentanyl/propofol group
Am J Emerg Med.1999;17:1-3
Use for diagnostic imaging
2 English studies N = 82, 34 with wt < 10 kg, 48 > 10 kg all received supplemental oxygen 10% transient hypotension, 1% hypoxia
Acta Anaesth sand.1996;40(5):561-5
N = 30 (1-10 yrs) all received supplemental oxygen 7% hypoxia secondary to apnea (resolved with
gental stimulation) no hypotension
Anesth.1993;79(5):953-8
Use in endoscopy
N = 50prospective randomized, propofol sedation
vs inhalational GApre procedure fasting36% hypotension, no treatment required24% hypoxia, corrected with nasal prongs20% reversible apnea
Gastro Endo.2002;55(1)
Use in the ED
N = 91prospective randomized, propofol vs
midazolam isolated extremity injuries, all received
morphine recovery times 14.9 +/- 11.1 in propofol
76.4 +/-47.5 min in Midazolam groupmild transient hypoxia 10% (similar in both
groups)Acad Emerg Med.1999;6(10):989-97
Propofol for kids
Pros rapid recovery titrateable no emergence
reaction
Cons line between
“conscious sedation” and borderline GA
incidence of apnea and hypoxia likely higher than with ketamine
small amounts of supporting data for use in ED
Ouch! It hurts!
Injection pain reported in 40-90% of all casesup to 50% of patients experience severe pain
recollection of pain is 50-80% post procedure recollection of pain severity post procedure
reflects pain on injection
Can J Anesth. 1995. 42:12 pp.1108-12
Br J Anaest. 1994. 72 pp.342-44
What has been looked at?
Temperature pHinjection site opioidslocal anaesthetics speed of
injectionsedatives NSAID’S
What really works???
What do the studies show?
Temperature warming to 37
oC or cooling to 4
oC makes no
difference compared to room temperatureAnaesthesia. 1998.53,pp79-88
Paed Anasth. 2000.10(2):129-32
Anesthesiology. 1998.89(4):1041
Anesthesiology. 1999.91(2):591
pH when decreased from 7.97 to 6.32 (with addition
of lidocaine or HCl) found decrease in painBr J Anaesth.1997;78:502-
506
What do the studies show?
Injection site dorsum of hand 50% experience pain antecubital fossa 0% experienced pain
Anaesthesia.1988;43(6):492-4
Speed of injection pain with bolus 50% vs 73% when given over
75 secAnaesthesia.1988;43(6):492-
4
What do the studies show?
NSAID’s 10 mg ketorolac + venous occlusion X 2 min
decreased pain ketorolac causes injection pain
Anaesth.2000;55:284-287
topical lidocaine + ionophoresis 50% placebo group described severe pain vs
75% with no pain and 25% with mild pain in lido group
Br J Anaest.1999.82(3):432-4
What do the studies show?
Metoclopramide reduction from 50% to 24% with pretreatment with 5-
10 mg iv, similar to effect with lidoBr J Anaest.1992;69:316-317
Acta Anasthes Scan.1999;43(1):24-7
Thiopental conflicting evidence >100mg decrease incidence of pain from 50% to 12%
Anaesthesia.1994;49:817-818
50mg no difference from controlsCan J Anesth.1995;42(12):1108-12
What do the studies show?
Fentanyl studied with 150ug injected with venous occlusion for
1 min. prior to propofol injection conflicting evidence
Acta Anaesthes Sinica.1997;35(4):217-21Mid East J Anesthes.1996;13(6):613-9
Alfentanil 1 mg injected prior to propofol decreases pain from
67-84% to 24-36% (similar to lido)
15ug/kg in kids similar to 0.5 mg/kg of lidoActa Anaesthes Scand.1992;36:564-68 Br J Anaesthes. 1994;72:342-44
Anesth Analg.1996;82:469-71
What the studies show
Lidocaine all studies show a reduction in pain scores with lido premixed within 30 min with propofol is better than pre-
injection with lidoAnaesthes.1985;43(6):91-2
Anaethes.1988;43(6):492-4
Dose? 3 studies have looked at doses > 20mg/induction doses of 0.4-0.6mg/kg for adults or 0.2 mg/kg for kids
appear to be more effective case series using 1mg/kg reduced pain to 0% (N=50)Anaesthes.1992;47:604-6 Anesthes.1995;83(3A):A385 Anaesthes.1990;45:70
lidocaine
Most effective analgesia with a bier block 0.5 mg/kg lidocaine rubber tourniquet to forearm for 30-120
sec absolute risk reduction of pain = 60% NNT = 1.6
Anesth Analg.2000;90(4):936-9
The bottom line
0.5 mg/kg lidocaine injected with a tourniquet is the best method to prevent pain
Premixed lidocaine with propofol works. I would use 0.5mg/kg
alfentanil 1mg prior to injection may further reduce pain
larger veins for infusion cause less pain
Laryngospasm
Laryngospasm
“a prolonged occlusion of the glottis caused by contraction of the intrinsic laryngeal muscles”
Am J Otol.1995;16(1):49-52
in general it is considered present when inflation of the lungs is impossible secondary to laryngeal muscle contraction and other causes are excluded (ie occluding tongue, bronchospasm)
Acta Anaesthes Scan.1984;28:567-575
What is the incidence
Unable to find any references citing frequency in the ED patient population
literature post GA: 0.87% in adults 1.23% age 0-9 yr 2.28% age 1-3 month
Acta Anaesthes Scand.1984;28:567-575
3-6% prospective data in kidsJ Clin Anesthes.1992;4(3):200-3
Potential Complications of laryngospasm
Bronchospasm 4.3%Hypoxia 3.5%Vomiting 8.1%Aspiration 1.2%Arrhythmia 1%Cardiac arrest 0.5%
Acta Anaesthes Scan.1984;28:567-575
in children, 9 of 293 cardiac arrest (3%) secondary to laryngospasm
Anesthesiology.2000;93(1):6-14
Risk Factors
Stimulation > depth of anesthesia
maintaining ETT with light anesthesia
Stimulation blood, mucous, vomitus laryngeal or trigeminal nerve stimulation
Risk Factors
URTI 2 fold higher risk of laryngospasm in kids with
active or recent URI undergoing GA
Anesthesiology.1996;85(3).475-480
Second hand tobacco smoke 9.5% vs 0.9% risk of laryngospasm with GA
Anesthes Analg.1996;82:724-7
Risk Factors
Type of airway adjunct facemask-oral airway < LMA = ETT
Can J Anesth.2000;47(4):315-18
Anesth Analg.1998;86:706-11
Anesthisiology.1998;88(4):970-77
case reports with use of jet ventilation intraop
Drugs case reports of midazolam or fentanyl causing
laryngospasmAnn Emerg Med.1998;32(2):263-5
Anaesth.1995;50(9):375
Crit Care Med.2000;28(3):836-9
Treatment of Laryngospasm
Stop the stimulus if possible
Jaw thrust counteracts the descent of the hyoid
and can reverse the ball valve effect
Treatment
CPAP apply 20-30 cm H2O apply constant pressure avoid gastric insufflation apply styloid pressure
Treatment
Succinylcholine timing depends on the clinical situation: can I break laryngospasm relatively quickly with
CPAP? What is the clinical status of the patient? Do I have time to wait for succinylcholine to work?
Doses as low as 0.1mg/kg iv have been shown to effectively treat laryngospasm (N = 3)
Anaesth.1993;48(3):229-30
Treatment: what if I don’t have iv access?
IM sux: sites: deltoid, quad femoris, intralingular dose: 3mg/kg
Treatment
Time to apnea after Sux:
IM deltoid / quads 210 secIM, tongue 75 secIV 35 sec
Anesth Analg.1968;47:605-15
Treatment
Time to max twitch depression:
IM quads 295 secIM tongue 265 secIM tongue + digital massage 133 sec
Anesth Prog.1990;37(6): 296-300
Treatment
Benefits of the submental approach: very vascular region fastest onset of action if iv not available can inject while masking
Treatment - other options
Nitroglycerin: N = 2 dose 4 microg/kg iv relief within 1 minute
Acta Anaeths Scan.1999;43(10):1081-3
intranasal lido + epi: N = 2 5 cc 1% lido with epi intranasal relief within 10 seconds
Ann Emerg Med.1985;14(3)275-6
Prevention
Literature available only looks at post op prevention fentanyl prior to laryngeal stimulation does not
prevent laryngospasm but does blunt airway reflexes
Anesthesiology.1998;88(6):1459-66
topical lidocaine (4mg/kg) prior to extubation decrease laryngospasm post T&A
Arch Otol.1991;117:1123-8
reduce modifiable risk factors
Laryngospasm: take home points
Simple maneuvers often workpractice good mask techniqueknow when to give suxif you don’t have an iv: submental sux
with digital massage is a good option