Paediatric Anaesthesia Formulas

Fluid requirements

Fasting Guidelines for Pediatric Patients

TYPE Fasting Time (hr)

Clear liquids* 2

Breast milk 4

TYPE Fasting Time (hr)

Infant formula 6†

Solid (fatty or fried) foods 8

*Includes only fluids without pulp; clear tea or coffee without milk products. †The American Society of Anesthesiologists guideline allows a “light breakfast” (tea and plain toast) 6 hours before anesthesia; however, determining what a “light breakfast” means for a child is difficult.

Maintenance Requirements in Children

Weight (kg) Maintenance Requirements in Children

(mL/hour)

0-10 4 (mL/kg)

11-20 40 + 2 (mL/kg)

> 20 kg 60 + 1 (mL/kg)

Replacement of Losses

Procedure Insesnsible losses

Non-invasive (inguinal hernia, clubfoot) 0-2 cc/kg/hr

Mildly invasive (uteteral reimplantation) 2-4 cc/kg/hr

Moderately invasive (bowel reanastamosis) 4-8 cc/kg/hr

Significantly invasive (NEC) > 10 cc/kg/hr

Intraoperative Glucose

Infants: 4 mg/kg/min = 240 mg/kg/hr maintenance requirements D5 = 50 mg/mL Delivery of D5 @

> 4 mL/kg/hr may lead to hyperglycemia

Catheter sizes and their flow rates

MEAN FLOW RATE RANGE (mL/min)

Catheter Size

(gauge)

Length

(inches)

Crystalloid

(gravity)

Crystalloid

(pressure)

Blood

(pressure)

24 0.75 14 to 15 42 to 47 20 to 30

22 1 24 to 26 65 to 77 44 to 50

20 1.25 to 2 38 to 42 103 to 126 69 to 81

18 1.25 to 2 55 to 62 164 to 214 150 to 164

16 2 75 to 81 248 to 280 216 to 286

MEAN FLOW RATE RANGE (mL/min)

Catheter Size

(gauge)

Length

(inches)

Crystalloid

(gravity)

Crystalloid

(pressure)

Blood

(pressure)

14 2 92 to 93 301 to 319 334 to 410

20 8 5 16 3

18 8 13 51 22

16 8 31 97 35

Data summarized from Hodge D III, Fleisher G: Pediatric catheter flow rates. Am J Emerg Med

3:403, 1985.

Paediatric Airway Equipments

Pediatric Endotracheal Tube Size

Age Internal

Diameter (mm)

Depth (cm)

Preterm 2.5 6 - 8

Term 3.0 9 - 10

6 months 3-3.5 10

1 - 2 years 4.0 10 - 11

3 - 4 years 4.5 12 - 13

5 - 6 years 5.0 14 - 15

10 years 6.0 16 - 17

Pediatric Endotracheal Tube Depth

For preemies and neonates (cm) = weight (in kg) + 6 For 1 year or older (cm) = age + 10 cm

Pediatric Airway Equipment

Age Miller Blade

< 32 weeks 00

Term 0 (< 3 kg)

3-18 mo. 1 (3-10 kg)

> 18 mo 2 (> 12 kg)

Pediatric LMA Size

LMA sizes ~ weight (kg) / 20 + 1 (round to nearest 0.5)

Laryngeal mask airway size characteristics

Laryngeal Mask Airway Size Approximate Weight (kg) Cuff Volume (mL)

1 <5 2 to 5

1.5 5 to 10 3 to 8

2 10 to 20 5 to 10

2.5 20 to 30 10 to 15

3 30 to 50 15 to 20

4 50 to 70 ≤30

5 70 to 100 ≤40

6 >100 ≤50

Pediatric-sized laryngeal mask airways and compatible endotracheal tubes[*]

Laryngeal

Mask Airway

Size

Maximum Lubricated

Uncuffed Standard

Endotracheal Tube Inner

Diameter (mm)

Maximum Lubricated Cuffed

Standard Endotracheal Tube

Inner Diameter (mm)

Maximum Flexible

Bronchoscope

Size[†]

1 3.5 3.0 2.7

1.5 4.0 4.0 3.0

2 5.0 4.5 3.5

2.5 6.0[‡]

5.0 4.0

3 — 6.0 5.0

4 — 6.0 5.0

5 — 7.0[†]

5.0

6 — 7.0[†]

5.0

Litman RS: The difficult pediatric airway. In Litman RS, editor: Pediatric anesthesia: The

requisites, St. Louis, 2004, Mosby. *Based o e peri e ts perfor ed the author, As per LMA North A eri a, Largest availa le u uffed endotracheal tube available at The Children's Hospital of Philadelphia.

Laryngoscope blade types and sizes

BLADE TYPE AND SIZE

Age Miller Wis-Hippel Macintosh

Premature neonate 0 — —

Term neonate 0 to 1 — —

1 to 12 mo 1 1 —

1 to 2 yr 1 1.5 2

2 to 6 yr 2 — 2

6 to 12 yr 2 — 3

Endotracheal tube size[*]

Age Weight

(kg)

ID (mm) Length (OT)

(cm)

Length (NT)

(cm)

Suction Catheter

(F)

Premie 0.7 to 1.0 2.5 7 to 8 9 5

Premie 1.0 to 2.5 3.0 8 to 9 9 to 10 5

Newborn 2.5 to 3.5 3.5 9 to 10 11 to 12 6

3 mo 3.5 to 5.0 3.5 10 to 11 12 6

3 to 9 mo 5.0 to 8.0 3.5 to 4.0 11 to 12 13 to 14 6

9 to 18 mo 8.0 to 11.0 4.0 to 4.5 12 to 13 14 to 15 8

1.5 to 3 yr 11.0 to

15.0

4.5 to 5.0 12 to 14 16 to 17 8

4 to 5 yr 15.0 to

18.0

5.0 to 5.5 14 to 16 18 to 19 10

6 to 7 yr 19.0 to

23.0

5.5 to 6.0 16 to 18 19 to 20 10

8 to 10 yr 24.0 to

30.0

6.0 to 6.5 20 to 22 21 to 23 10

10 to 11

yr

30.0 to

35.0

6.0 to

6.5[†]

20 to 22 22 to 24 12

12 to 13

yr

35.0 to

40.0

6.5 to

7.0[*]

20 to 22 23 to 25 12

14 to 16

yr

45.0 to

55.0

7.0 to

7.5[*]

20 to 22 24 to 25 12

Data modified from Smith RM: Anesthesia for infants and children. CV Mosby, 1980, St. Louis;

Davenport HT: Paediatric anaesthesia. Year Book Medical Publishers, 1973, Chicago.

ID, inner diameter; OT, orotracheal tube; NT, nasotracheal tube; F, French size (number is

approximately equal to ID × 4).

* The endotracheal tube should fit so as to allow full normal expansion of both lungs with positive airway

pressure ut to per it a gas leak a out the tu e at 20 to 25 H2O. Cuffed tu e.

Recommended nasotracheal tube dimensions

TUBE LENGTH (L) (cm)

Age (yr) Tube Size (S) (ID, mm) Yates et al. (1987) Rees (1966) Steward (1979)

0 to 3 mo 2.5 to 3.0 9.5 to 11.0 11.8 13.5

4 to 7 mo 3.5 to 4.0 12.5 to 14.0 13.6

1 4.0 14.0 14.5 15.0

2 4.5 15.5 15.2 16.0

3 4.5 to 5.0 15.5 to 17.0 15.6

4 5.0 17.0 16.5 17.0

5 5.0 to 5.5 17.0 to 18.5 16.8

6 5.5 18.5 17.1 19.0

7 5.5 to 6.0 18.5 to 20.0 17.8

8 6.0 20.0 18.3 21.0

9 6.0 to 6.5 20.0 to 21.5 18.8

10 6.5 21.0 19.1 22.0

11 6.5 to 7.0 21.5 to 23.0 19.1

12 7.0 23.0 22.0

Medications for Children

Preoperative Medication in Children

PO Nasal IV IM

Midazolam 0.5 - 1.0 mg/kg 0.05 - 0.10 mg/kg

Fentanyl 1 - 3 ucg/kg

Morphine 0.05 - 0.10 mg/kg

Sufentanil 0.25 - 0.5 ucg/kg

Ketamine 2-4 mg/kg 4-6 mg/kg

Resuscitation Medication in Children

Epinephrine = 10-100 ucg/kg for arrest (100 ucg/kg in ETT), 1-4 ucg/kg for hypotension

Atropine = 0.01 - 0.02 mg/kg (0.3 mg/kg in ETT) - actual dose 0.1 - 1 mg

Adenosine = 0.1 mg/kg (max dose 6 mg)

Lidocaine = 1-1.5 mg/kg

SCh = 2-3 mg/kg

Rocuronium 1 mg/kg

Calcium chloride = 10-20 mg/kg (dilute to 10 mg/cc or else veins will sclerose, try to give

centrally if possible)

Bicarbonate = 1 mEq/kg (dilute to 1 mEq/cc or else veins will sclerose)

Naloxone = 0.1 mg/kg

DEFIBRILLATION = 2 J/kg (can increase up to 4 J/kg)

Preoperative Medication in Children

Midazolam 0.05-0.1 mg/kg IV (0.5-1 mg/kg PO, 15 mg max)

Methohexital 1-2 mg/kg IV (25-30 mg/kg PR, 500 mg max)

Ketamine 1-2 mg/kg IV, 10 mg/kg IM, 5-8 mg/kg PO

Sodium Pentothal 1-2 mg/kg IV (separation), 4-6 mg/kg IV (induction)

Propofol 0.1-1 mg/kg IV (separation), 2-4 mg/kg IV (induction)

Etomidate 0.2-0.3 mg/kg IV

Antibiotic Doses in Children

Cefazolin 25 mg/kg q6-8h up to 1-2 grams

Cefotaxime 20-30 mg/kg q6h

Ampicillin 50-100 mg/kg q6h up to 3 grams

Gentamicin 2-2.5 mg/kg q8h (must monitor serum levels, longer interval in renal

impairment)

Clindamycin 5-10 mg/kg q6-8h up to 900mg

Mezlocillinn 50-100 mg/kg q6h up to 2g

Vancomycin 10 mg/kg q6h up to 1g

Other Useful Medication in Children

Glycopyrrolate 0.01 mg/kg IV, IM, ETT (max 0.4 mg)

Morphine 0.05 - 0.1 mg/kg IV (max 0.4 mg/kg)

Fentanyl 1-5 ucg/kg IV

Ketorolac 0.5 mg/kg IV

Tylenol 20 mg/kg PO, 40 mg/kg PR

Zofran 0.05-0.15 mg/kg

Droperidol 20-25 ucg/kg

Dexamethasone 0.1-0.5 mg/kg for pain, N/V prophylaxis

Neostigmine 0.07 mg/kg

Dexamethasone 0.5-1 mg/kg for tracheal edema

Solumedrol 1 mg/kg IV

Characteristics of volatile anesthetics

MAC (%)

Infant (1 to 6 mo) Child (3 to 10 yr) Adult

Halothane 1.1 0.9 0.7

Enflurane –– –– 1.6

Isoflurane 1.7 1.6 1.2

Desflurane 9.4 8.0 6.0

Sevoflurane 3.3 2.5 2.0

Adapted in part from Jones RM: Desflurane and sevoflurane; inhalation anesthetics for this

decade? Br J Anaesth 65:527, 1990. Copyright © The Board of Management and Trustees of the

British Journal of Anaesthesia. Reproduced by permission of Oxford University Press/British

Journal of Anaesthesia.

Intravenous dosage of opioids in children

Drug As Major Anesthetic As Adjunct As Postoperative

Analgesic

Morphine 2 to 3 mg/kg 0.05 to 0.1 mg/kg per hr 0.05 to 0.1 mg/kg

Fentanyl 50 to 100 mcg/kg 1 to 3 mcg/kg per hr 1 to 2 mcg/kg

Sufentanil 10 to 15 mcg/kg 0.1 to 0.3 mcg/kg per hr —

Alfentanil 150 to 200 mcg/kg 1 to 3 mcg/kg per min —

Remifentanil 0.2 to 1.0 mcg/kg per

min

0.1 to 0.4 mcg/kg per

min

—

Hydromorphone 5 to 10 mcg/kg 3 to 5 mcg/kg per hr 3 to 5 mcg/kg

Intravenous doses of muscle relaxants in children

MAINTENANCE ED95 (mg/kg)

Drug Intubation

(mg/kg)

Bolus

(mg/kg)

Continuous Infusion

(mcg/kg/m)

Infants Children

Mivacurium 0.2 to 0.3 0.1 10 to 20 0.1 0.1

Cisatracurium 0.15 0.1 1 to 5 0.05 0.05

Vecuronium 0.05 to 0.1 0.025 1 0.024 0.026

Rocuronium 0.8 to 1.0 0.3 to 0.5 15 0.2 0.3

Pancuronium 0.1 0.5 — 0.05 0.05

Pipecuronium 0.1 — — 0.035 0.05

Nonsteroidal anti-inflammatory drugs (NSAIDs)

Drug Age Group Dose (mg/kg) Interval

Acetaminophen Preterm Term Load: 20; 15(PO), 20 (PR) q12h

>3 mo Load: 20 to 30; 20 (PO) q8h

Load: 20 (PO); 15 (PO) q4h

40 (PR), 20 (PR) q6h

Diclofenac >1 yr 1 (PO) q8h

Ibuprofen >6 mo 10 to 15 (PO) q6h

Ketorolac >6 mo 0.25 to 0.5 (IM, IV) q6h

Naproxen >6 mo 5 to 10 (PO) q8–12h

Celecoxib >1 yr 1.5 to 3 (PO) q12h

Regional Anaesthesia

I. DOSES OF EPIDURAL ANALGESICS

Usual Doses and Infusion Regimens for Epidural Anesthesia in Pediatric Patients

Agent Initial Dose Continuous Infusion (Max.

Doses) Repeat Injections

Bupivacaine,

levobupivacaine

Solution: 0.25% with

5 µg/mL (1/200,000)

<4 mo: 0.2 mg/kg/hr

(0.15 mL/kg/hr of a 0.125%

0.1 to 0.3 mL/kg

every 6-12 hr of a

Agent Initial Dose Continuous Infusion (Max.

Doses) Repeat Injections

epinephrine

Dose:

<20 kg: 0.75 mL/kg

20-40 kg: 8-10 mL (or

0.1 mL/year/number of

metameres)

>40 kg: same as for adults

solution or 0.3 mL/kg/hr of

a 0.0625% solution)

4-18 mo: 0.25 mg/kg/hr

(0.2 mL/kg/hr of a 0.125%

solution or 0.4 mL/kg/hr of

a 0.0625% solution)

>18 mo: 0.3-0.375 mg/kg/hr

(0.3 mL/kg/hr of a 0.125%

solution or 0.6 mL/kg/hr of

a 0.0625% solution

0.25% or 0.125%

solution (according to

pain scores)

Ropivacaine

Solution: 0.2%

Dose: same regimen in

mL/kg as for bupivacaine

(see above)

Same age-related infusion

rates in mg/kg/hr as for

bupivacaine (usual

concentration of

ropivacaine: 0.1%, 0.15%,

or 0.2%)

Do not infuse for more than

36 hr in infants < 3 mo

0.1 to 0.3 mL/kg

every 6-12 hr of a

0.15% or 0.2%

solution (according to

pain scores)

Adjuvants

Avoid in infants < 6 mo

Fentanyl (1-2 µg/kg) or

sufentanil (0.1-0.6 µg/kg)

or clonidine (1-2 µg/kg)

Select only one additive:

Fentanyl: 1-2 µg/mL

Sufentanil: 0.25-0.5 µg/mL

Morphine: 10 µg/mL

Hydromorphone: 1-3 µg/mL

Clonidine 0.3 at 1 µg/mL of

solution

Morphine (without

preservatives): 25-

30 µg/kg every 8 hr

Recommendations for dosing caudal and epidural blocks.

Concentration Dose Possible Additives

Single-dose caudal 0.175% to

0.5%

0.75 to 1.25 mL/kg not

to exceed 3 mng/kg

Epinephrine 2.5 to 5

mcg/mL

Clonidine 1 to 2 mcg/kg

Morphine 30 to 70

mcg/kg

Continuous caudal or lumbar

epidural catheters

0.1% to 0.25% 0.4 mL/kg per hr or 0.2

to 0.4 mg/kg per hr

Fentanyl 2 to 5 mcg/mL

Hydromorphone 5 to 10

mcg/mL

Continuous thoracic epidural 0.1% to 0.25% 0.3 mL/kg per hr or 0.1

to 0.2 mg/kg per hr

Fentanyl 2 to 5 mcg/mL

Hydromorphone 5 to 10

mcg/mL

Bupivacaine, levobupivacaine, or ropivacaine may be used. Greater concentrations and larger doses

should be reserved for levobupivacaine or ropivacaine. Doses and concentrations should be reduced

in infants. Children less than 2 years of age who receive morphine centrally require 24-hour

monitoring after its delivery.

II. SPINAL ANAESTHESIA DOSES

Volumes of local anesthetic solutions for peripheral nerve blocks and regional anesthesia in

children

Block Volume (mL/kg)

Axillary 0.2 to 0.5

Interscalene 0.33

Sciatic 0.15 to 0.2

Femoral 0.5

Intravenous 0.5 to 10

Caudal 0.5 to 1.0

Intrapleural (infusion) 0.5 (per hr)

Usual Doses of Local Anesthetics for Spinal Anesthesia in Neonates and Former Preterm

Neonates Younger than 60 Weeks of Preconceptual Age (up to a Weight of 5 kg)

Local Anesthetic Dose (mg/kg) Volume (mL/kg) Duration (min)

Tetracaine 1% 0.4-1.0 0.04-0.1 60-75

Tetracaine 1% with epinephrine 0.4-1.0 0.04-0.1 90-120

Bupivacaine 0.5% isobaric or hyperbaric 0.5-1.0 0.1-0.2 65-75

Levobupivacaine 0.5% 1.0 0.2 75-88

Ropivacaine 0.5% 1.08 0.22 51-68

Usual Doses of Local Anesthetics for Spinal Anesthesia in Children and Adolescents

Local Anesthetic Usual Dose(s)

0.5% Isobaric or hyperbaric bupivacaine 5 to 15 kg: 0.4 mg/kg (0.08 mL/kg)

>15 kg: 0.3 mg/kg (0.06 mL/kg)

0.5% Isobaric or hyperbaric tetracaine 5 to 15 kg: 0.4 mg/kg (0.08 mL/kg)

>15 kg: 0.3 mg/kg (0.06 mL/kg)

0.5% Isobaric levobupivacaine 5 to 15 kg: 0.4 mg/kg (0.08 mL/kg)

Local Anesthetic Usual Dose(s)

15-40 kg: 0.3 mg/kg (0.06 mL/kg)

>40 kg: 0.25 mg/kg (0.05 mL/kg)

0.5% Isobaric ropivacaine 0.5 mg/kg (max 20 mg)

III. RECOMMENDATIONS FOR DOSING OF PERIPHERAL NERVE BLOCKS

Recommended Volumes of Local Anesthetic for Single-Shot Upper Limb Blocks with

Neurostimulation by Patient Weight

Patient Weight

Conduction Block ≤10 kg 11-30 kg 31-60 kg >60 kg

Brachial plexus above

clavicle 1 mL/kg

10 mL + 0.5 mL/kg

above 10 kg

20 mL + 0.25 mL/kg

above 30 kg 30 mL

Brachial plexus below

clavicle 0.5 mL/kg

5 mL + 0.25 mL/kg

above 10 kg

10 mL + 0.15 mL/kg

above 30 kg 15 mL

Any nerve trunk at

elbow 0.2 mL/kg 0.15 mL/kg 0.15 mL 10 mL

Any nerve trunk at

wrist 0.05 mL/kg 0.05 mL/kg 0.05 mL/kg

3-

5 mL

Recommended Volumes of Local Anesthetic for Single-Shot Lower Limb Blocks with

Neurostimulation

Conduction Block ≤10 kg 11-30 kg 31-60 kg >60 kg

Lumbar plexus (psoas

compartment) 1 mL/kg

10 mL + 0.5 mL/kg

above 10 kg 20 mL 20 mL

Femoral 0.5 mL/kg 5 mL + 0.35 mL/kg

above 10 kg

12 mL + 0.3 mL/kg

above 30 kg 25 mL

Fascia iliaca 1 mL/kg 10 mL + 0.5 mL/kg

above 10 kg

20 mL + 0.25 mL/kg

above 30 kg 30 mL

Proximal sciatic 1 mL/kg 10 mL + 0.5 mL/kg

above 10 kg

20 mL + 0.3 mL/kg

above 30 kg 30 mL

Sciatic in popliteal fossa 0.3 mL/kg 3 mL + 0.2 mL/kg

above 10 kg 6 mL + 0.15 mL/kg 12.5 mL

Usual Local Anesthetic Infusion Rates with or without Bolus Doses of Either Ropivacaine

0.2%, Bupivacaine 0.125%, or Levobupivacaine 0.15% to 0.2% for Continuous Peripheral

Nerve Blocks

Techniques Plexus and Proximal Conduction Nerve

Blocks *

Axillary and Popliteal

Blocks

Infusion rate 0.2 mL/kg/hr up to 10 mL/hr 0.1 mL/kg/hr up to

5 mL/hr

Bolus doses 0.2 mL/kg up to 5 mL 0.1 mL/kg/hr up to

3 mL/hr

Maximum bolus doses per

hour 3 3

Regional Technique Bolus Dose

(mLμ/kg)[*]

Continuous Infusion (mLμ/kg per hr)

Axillary Parascalene 0.2 to 0.5 0.2 to 0.4 0.1 to 0.2 0.1 to 0.2

Femoral or lateral femoral

cutaneous

0.3 to 1 0.15 to 0.3

Fascia iliaca 0.5 to 1 0.15 to 0.3

Lumbar plexus 0.5 to 1 0.15 to 0.3

Sciatic 0.3 to 1 0.15 to 0.3

Ilioinguinal/iliohypogastric 0.25 NA

Penile block 0.1 NA

Paravertebral 0.5 0.2 to 0.25

NA, not applicable.

Bupivacaine, levobupivacaine, or ropivacaine may be used. For bolus dosing, lower concentrations

such as 0.2% to 0.25% should be used in infants and young children, whereas concentrations of

0.375% to 0.5% should be used in children >5 to 8 years of age. For continuous infusions, lower

concentrations such as 0.1% to 0.2% of all agents are acceptable

Ref:

1. SMITH'S Anesthesia for Infants and Children, Seventh Edition.

2. Miller's Anesthesia - 8th ed.