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Acute Perioperative Pain Management in Children

Nancy L. Glass, MD, MBA, FAAP

Professor of Anesthesiology and Pediatrics, 

Baylor College of Medicine and Texas Children’s Hospital

April 2014

I have no financial disclosures relevant to this presentation.

Goals & Objectives

1. Develop an age‐appropriate pain plan for inpatient, perioperative pain management, recognizing the indications for adjuncts and regional anesthetic techniques

2.  Develop an age‐appropriate pain plan for outpatient, perioperative pain management, recognizing the indications for adjuncts and regional anesthetic techniques

3.  Recognize risk factors for complications of analgesic therapy

At the end of this presentation, participants should be able to:

A Simpler Goal

Give everyone in the audience at least ONE NEW and USEFUL TOOL for managing pain in pediatric patients

Agenda

• Measurement of pain in children

• Systemic therapy

– Nonopiates

– Opiates

– Adjuncts

• Regional analgesia

We are NOT going to cover Neonatal Pain today, because that’s another whole lecture!

Gadget‐Lover’s Pain‐O‐Meter!

Asleep

Tickle

Ouch

Hurt

Agony

Wouldn’t it be great if we had a magic

machine or test that would quantify our

patients’ pain?

Measurement of Pain

• Common tools

– Physiologic

– Behavioral

– Self‐report

• Limitations

• Future directions

http://www.psych.ubc.ca/

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Physiologic Signs of Pain

• Hypertension, tachycardia, tachypnea‐‐not reliable, not specific for pain

• Physiologic signs fade over time

• Not a good way to tell if your patient is in pain

Behavioral Scales

• Use observed behavior to assess pain, and to  follow the course over time

• Apply in children less than 3 yrs, may use along with self‐report from 3‐6 yrs

• Commonly used behavioral scales include the FLACC and the CHEOPS

• FLACC‐R is a slightly different form for developmentally delayed/impaired children

Behavioral Scale

Think of this as an “Apgar score for Pain”…except that high scores are BAD!

Well-validated, easy to use

A slightly different form is available for impaired children Faces Scales

Faces Pain Scale-Revised

Wong-Baker Faces Pain Rating Scale

May be useful beginning between 3 and 6 yrs of age

50% of 6 yo were unable to use a

Faces scale

Von Baeyer CL, Pain Res Manag, 2009

Neutral anchor

Anchor NOT

neutral

Pain score of 3 (6/10) is the earliest sign of distress in this scale

Pain score of 2/10 shows beginning distress

Oucher Pain Scales

Color photographs of children’s faces, of both genders and many ethnic groups. Need for color copying, multiple versions—limit the usefulness of the Oucher scales. Vertical scales ARE preferable, with respect to children’s cognitive development.

“Pieces of Hurt”, Poker Chip Tool

• Ages 3 ‐6 yrs

• Give child FOUR poker chips, they return some to examiner

• Used as comparison tool for other scales

• Not clinically practical

“Give me one chip for a little hurt, two chips for a bigger hurt….”

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Visual Analogue Scale (VAS)

• Standardized to 10 cm line, no numbers or lines

• Requires clinician to measure position of response

• Validated for children > 7y

When invited to choose, most children select a Face scale, even if they are old enough to use a VAS

Verbal Numeric Rating Scales

• “How much pain are you having now, on a scale of 0 to 10, where 0 is no pain, and 10 is the worst pain imaginable?”

• Most commonly used scale for children > 8 yrs

This scale has NOT been validated for

use in children!

How the question of “most pain” is asked introduces bias into response

Limitation of Pain Scores

• Cannot use pain scores to compare amt of pain between pts

• Both patients responded to starting PCA

• But how much response is “enough?”  Does reduction from 8 to 5 represent treatment success, or “just a start?”  What is a clinically meaningful response?  We don’t know!

Von Baeyer CL, Pain Res Manag, 2009

Two patients, Pat and Chris, both receive a PCA…

Interpretation / Limitations            of Pain Scores

• Age

• Context

• Patient’s experience and expectations

• Who’s asking?

• Imperfect tools

“Reducing the experience of pain to a single number reflecting intensity is a gross oversimplification.”

“Before making further efforts to impose the use of pain scales on reluctant practitioners, one should have better evidence that it actually makes a difference in outcome.”

Von Baeyer CL , 2009; Franck LE, Bruce E, 2009

Not All Distress is Pain

• Depression

• Disorientation

• Altered sensory perception from anesthesia or blocks 

• Fear, anxiety

• Hypoglycemia

• Distended bladder

• Nausea

• Hypoxia, hypoventilation

Not All Distress is Pain

Not a validated scale, but you probably understand what we’re getting at here!

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World Health OrganizationPain Ladder

Non-opioid analgesics

Oral opiates

IV opiates

Physical measures: RICE protocol

This ladder is familiar: what’s important to recognize is that surgical patients begin their journey at the TOP of the ladder!

Basic AgentsAcetaminophen and Ibuprofen, PO or IV

The “T’s”Ketorolac (Toradol)—IV, 

Tramadol, Tapentadol—PO 

Stronger, Systemic OpiatesMorphine, Hydromorphone, Fentanyl

Methadone

Oral OpiatesCodeine, Hydrocodone, Oxycodone

Combined with acetaminophen or ibuprofen

OR

Multi-modal analgesia: combining agents from different classes to minimize opiate requirements and reduce toxicity

Systemic Therapy

Nonopioids

• Acetaminophen—oral, rectal, IV

• NSAIDs

– Ibuprofen (Advil®)—oral and now IV—Q4‐6h

– Naproxen (Aleve®)—only twice daily dosing

– Meloxicam (Mobic®)—only once daily dosing

– Ketorolac—IV 

IV Acetaminophen“Ofirmev”

• FDA approved since Nov 2010, on    formulary at TCH since April 2011

• In Epic:  look for Ofirmev

• Dose: 15 mg/kg Q 6h, max 1 gm Q6h;         dose adjustments for the youngest infants—check formulary

• Great for NPO kids, kids who cannot/should not receive PR tylenol

• Demonstrates opiate‐sparing effects

CHEAP!Wholesale

cost of 1 gm, only $10.60

• In Epic:  when you change from IV to oral agents, it does not recognize that you are giving too much acetaminophen!

• You have to manually D/C the Ofirmev at the time you add an acetaminophen‐containing oral opiate

IV Acetaminophen“Ofirmev”

Ofirmev—increased N/V?

Jun‐10 Jul‐10 Aug‐10 AVG Jun‐11 Jul‐11 Aug‐11 AVG

Spines with PCA 32 21 11 21.3 35 20 14 23

# mild PONV 2 0 0 0.7 0 1 3 1.3

# mod‐sev PONV 5 2 0 2.3 6 9 1 5.3

% PONV total 21.9% 9.5% 0.0% 10.5% 17.1% 50.0% 28.6% 31.9%

% mod‐severe PONV 15.6% 9.5% 0.0% 8.4% 17.1% 45.0% 7.1% 23.1%

Pectus with Epid 16 5 0 7 16 10 6 10.7

# mild PONV 1

# mod‐sev PONV 1 1 0 3 6 0

% PONV total 16.7%

% mod‐severe PONV 6.3% 20.0% 0.0% 8.8% 18.8% 60.0% 0.0% 26.3%

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IV Ibuprofen

• FDA approved June 2009 for patients > 16 yrs

• Pediatric trials underway to extend indications

– T&A patients 8‐17yrs, single preop dose

– Fever protocol, newborn to age 17

• Similar SE/risk profile to other NSAIDs, but lower risk of GI bleed than ketorolac

• Dose:  10 mg/kg IV Q6h

• NOT limited to 5 day useThanks to Priscilla Garcia, MD

for sharing this info!

Between the “weak” opiates and the “strong” opiates……The T’s

• Ketorolac (Toradol®)

• Tramadol

• Tapentadol

Ketorolac (Toradol®) Ibuprofen (Caldolor®)

Indications Moderate to severe pain that requires analgesia at opioid level

Age: 2 years and older

‐Mild to moderate pain‐Moderate to severe pain as an adjunct to opioid analgesics‐Reduction of fever

Age: 17 years and older

Dosing Initial 0.5 mg/kg ‐1 mg/kg followed by 0.5 mg/kg IV every 6 hours, max 30 mg/dose

Pain: 400 to 800 mg IV over 30 min every 6 hours

Fever: 400 mg IV over 30 min every 4‐6 hours or 100‐200 mg every 4 hours

Max 3200 mg daily dose

Duration  Maximum 5 days (20 doses) Unrestricted

Thanks to Priscilla Garcia, MD for sharing this slide!

Contraindicated in renal dysfunction, GI bleed hx/risk, breast-feeding moms; concern re: asthma, T&A

Tramadol (Ultram®)

• Mechanism

– Weak binding at mu opiate receptor

– Also blocks ascending pain pathways by inhibiting norepinephrine / serotonin reuptake

– Metabolized by CYP2D6

• GOOD for chronic pain 

• Dose 1‐2 mg/kg/dose Q 4‐6h, max 100 mg/dose, max 400 mg/day Less respiratory

depression, less N/V, less sedation

• Tablet form, 50 mg only; also comes as Extended Release form

• Two forms exist:  one WITH and one WITHOUT acetaminophen (great choice for acute pain management for patients who can’t take acetaminophen—but TCH only has “plain”)

• Be careful when combining with SSRI or SNRI anti‐depressants:  may cause serotonin syndrome

Tramadol (Ultram®) Tapentadol (Nucynta®)

• Oral, Schedule II agent

• Mechanism of action

– Mu receptor opiate agonist

– Norepinephrine reuptake inhibition

• Good side effect profile, esp GI

• May be particularly useful for chronic pain

• Not approved for use in children < 18 yrs

Wade WE, Clinical therapeutics, 2009

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Cool Epic Trick

• Order Ketorolac Q 6h on 12‐6‐12‐6 schedule

• Order Ofirmev Q 6h on 3‐9‐3‐9 schedule, so that the two agents are staggered

BOTH Ketorolac AND IV Acetaminophen have been shown to have opiate‐sparing 

effects!

Opiate‐sparing Effects

Why do we care about this?

•Less nausea and vomiting

•Earlier return of bowel function

•Less constipation

•Less sedation

Oral Opioids

• “Nontraditional” oral opioids

– Tramadol

– Tapentadol

• “Traditional” Oral opioids

– Codeine

– Hydrocodone

– Oxycodone

Codeine

• Metabolized to morphine by CYP2D6, associated with 4 phenotypes, including:   poor metabolizers (30%), ultra‐rapid metabolizers (up to 30%)

• Unpredictable efficacy, high incidence of N/V

• Risk of toxicity 

• Most pain experts have abandoned this agent

Hydrocodone

• Metabolized to hydromorphone by CYP2D6

– Concern about ultra‐rapid metabolizers and perioperative death

• Multiple preparations

– HC 5 mg / Aceta 500 mg

– HC 7.5 mg / Aceta 325 mg

– HC 10 / Aceta 325 mg

Vicodin®Hycet® elixir

2 tabs every 4 hours for adolescent

HC doseAcetamindose, mg

HC 5/500 60 6000

HC 7.5/325 90 3900

The FDA ruled that the Acetaminophen component must be reduced to 325 mg to decrease the risk of inadvertent overdose. Look for changes in formulation soon!

Hydrocodone

• Almost 6 yo died from excessive doses of hydrocodone during resp infection:  no hydromorphone found in body; genetic studies showed reduced CYP2D6 function1

• Child with OSA found dead following “normal” dose of hydrocodone, found by genetic studies to be ultra‐rapid metabolizer.2

1Madadi P, Pediatrics, 2010. 2 Personal communication.

This genetic test is not clinically available

right now.

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Oxycodone (OxyContin®)

• Multiple dosing forms

• ? Safer agent?

• Lower incidence of N/V, resp depression

• High abuse potential in community

Oxycodone

• Minimally metabolized by CYP2D6

• Major influence CYP3A4

• TCH formulary

– Oxycodone 5 mg

– Oxycodone + Acetaminophen 325 mg (PERCOCET)

• Roxicet oral solution

– Oxycodone 5 mg / Acetaminophen 325 per 5 ml

DOSE 0.15 mg/kg/dose Q 4-6 h

Intravenous Opioids

Morphine

Hydromorphone

Fentanyl

Methadone

• Not everyone needs a PCA!

• Oral opiates + IV Morphine for breakthrough may be sufficient

• IV single dose opiates must be available every 2 hours

• Morphine 0.1‐0.15 mg/kg IV Q2h prn

Patient‐Controlled Analgesia

• Which drug?– Morphine, Hydromorphone, Fentanyl:  no evidence that one is superior to another

– Demerol no longer available

• Continuous or just interval?– side effects and risks with background infusion

– Interval dose should always be larger            than the continuous infusion

For PCA: The devil’s in the details!

Common PCA Doses

Loading Dose

Continuous Infusion

Interval Dose

Lockout Interval

4 hour Max

Morphine .05‐0.1 mg/kg

0.01‐0.015 mg/kg

0.015‐0.025 mg/kg

6‐12 min 0.15‐0.35 mg/kg

Hydro‐morphone

5‐15 mcg/kg

3‐5 mcg/kg/hr

3‐5 mcg/kg

6‐15 min 50‐60 mcg/kg

Fentanyl 1 mcg/kg

0.1 mcg/kg/hr

0.15‐0.3 mcg/kg

6‐8 min 3‐5 mcg/kg

If background infusion used, the hourly rate of the infusion should always be less than the interval dose

PCA Challenges

• Analgesia

– Not comfortable when PCA started

– Interval dose too low, infusion too high

• Poor sleep quality

• Side effects—consider naloxone infusion

– Itching

– Nausea/vomiting

– Oversedation, respiratory depression

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A. Patient not comfortable to start with, interval doses only briefly lead to analgesia

The “sweet spot,” starting comfortably, staying there!

B. Barely comfortable to start with, level falls, takes many “pushes” to get comfortable again

C. Comfortable when PCA starts, but infusion is too high, so patient becomes increasingly somnolent with respiratory depression

PCA by Proxy (Surrogate)

• Younger children, developmentally delayed

• Alterations in PCA orders—slightly longer intervals, interval dose based on safe hourly doses of agent

In a study comparing “regular” PCA with PCA by proxy (PCA-P):

•PCA and PCA-P showed similar prevalence of adverse events: 22 % vs. 24%•PCA-P pts were more likely to need “rescue” or escalation of care to ICU setting•Risk factors: orthopedic surgery, cognitive impairment, respiratory co-morbidity, use of basal infusion, concomitant use of diazepam

Voepel-Lewis et al, Anesth Analg , 2008

Methadone

• Excellent analgesia

– Opiate receptor agonist

– NMDA receptor antagonist

• Pharmacokinetics—long T1/2….19‐24 hrs 

• Warnings

– Increased death rate:  < 5% opiates, > 20%  deaths

– Lack of understanding of how to use it…difficult to use well

– QT prolongationWould you let your 16 yo drive a Ferrari? Well, Methadone’s kinda like that—difficult to use well, and dangerous too—leave it to the experts, and stay out of trouble!

Postop Pain Management for    Patients Already Receiving Opiates

• Continue baseline opiate to prevent withdrawal

• Consider use of long‐acting, or extended release preparation

• Use PCA therapy for acute pain

• Use regional anesthesia/analgesia whenever possible

• Consider Pain Service Consult

Opioid Rotation

• Probably not necessary for the vast majority of children with acute perioperative pain

• May play a role for chronic pain, palliative care or hospice medicine

Weaning Opioids

• When the surgical condition is improving, pt tolerating PO

• Weaning PCA

– Start an oral agent

– Wean continuous infusion first, then lengthen interval between bolus doses

• Weaning oral meds at home—tips for success

– Continue non‐opioids/adjuncts

– Eliminate night‐time dose last

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“Abuse” of Pain Medicines

• Tolerance is common

• Addiction is rare in pediatric patients

• Family diversion is problematic

– Electronic record helps

– Medicaid pharmacy helps

Adjuncts

• Gabapentin

– May reduce opiate requirement when given preoperatively

• Ketamine

– NMDA receptor antagonist

– May reduce postoperative opiate requirements

– State‐by‐state variation in whether or not RNs may administer Ketamine

PatchesFentanyl LidoDerm®

Diclofenac, Flector®

NO ROLE in acute

perioperative pain

management!

Analgesia for Perioperative Procedures

• Chest tube removal

• Suture & central line removal

• Cardioversion

• Debridement of wounds / extensive dressing changes

Analgesia vs. Sedation vs. Anesthesia

Regional Anesthesia / Analgesia

• Reduces requirement for general anesthesia

• Faster wake‐up

• Less systemic opiate, postoperative analgesia

• Reduces risk of DVT

• Facilitates cough/deep breathing

• Facilitates early ambulation

• Shortens duration of ileus

Epidural Analgesia

• Caudal

• Lumbar

• Thoracic—direct, or threaded from caudal space

• Local anesthetic + opiate

• Time‐ & labor‐intensive

Walking: expected with thoracic epid, +/- with lumbar

Voiding without foley: usually with thoracic, not with lumbar

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• Brachial plexus

• Branches of lumbar plexus—femoral & sciatic

• Head and neck blocks

Nerve Block Analgesia

Single shot or plexus catheter placement

Suresh and Voronov, Ped Anes, 2012

Sciatic block

Supraorbital nerve block for VP Shunt placement

Nerve Block Analgesia

• Intercostals T7‐T12

• Ilioinguinal, iliohypogastric n

• Lat branches of L1‐3 rami

• Appendectomy

• Abdominal wall surgery

• Ostomy creation/closure

• Kidney transplant

McDonnell J, et al.  Anesth Analg 104(1):193‐7, 2007

Transverse Abdominis Plane Block—TAP

Suresh S, Chan VW, Paediatr Anaesth. 19(4):296‐9, 2009 

Multi‐modal Analgesia for Surgical Outpatients

• Scheduled ibuprofen or other NSAID, PLUS

• Acetaminophen‐containing opiate—hydrocodone preferred (Vicodin® or Hycet®)

…OR…

• Scheduled ibuprofen, PLUS

• Tramadol

1) Scheduled NSAID when appropriate:  Ibuprofen or Ketorolac, PLUS

2) Scheduled Acetaminophen (IV or PO), PLUS

3a) Morphine or hydromorphone IV every 2 hours PRN OR

3b) Morphine or hydromorphone PCA, OR

3c) Regional anesthetic technique

Multi‐modal Analgesia for Surgical In‐patients

Pain Service Consults

• “Big” procedures, particularly those for which regional anesthesia is recommended

• Patients on chronic opiates

• Patients with neuropathic pain

• Weaning opiate‐tolerant patients

• Palliative or terminal care

Summary

The ideal pain plan for both inpatients and outpatients includes a multi‐modal approach, 

designed to maximize comfort and minimize side effects and toxicity

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To cure sometimes, to relieve often, 

to comfort always…

15th century French folk saying, inscribed on the statue of Dr. Edward Trudeau in upstate New York