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