Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams...

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Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University

Transcript of Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams...

Page 1: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Anesthesia During the First Year of Life

Hany El-Zahaby, MD

Dept. of Anesthesia, Ain Shams University

Page 2: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

“Safe and effective anesthesia for neonates & infants undergoing surgery is one of the most challenging tasks presented to

anesthesiologist.”

Knowledge

Manual skills

Continuous practice

+

Adequate monitoring

Outcome

Page 3: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.
Page 4: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Age-specific considerations Airway differences –Infant Vs Adult

Big head, small bodyTongue/Epiglottis relatively largerGlottis more superior, at level of C3 (vs C4 or 5)Cricoid ring narrower than vocal cord aperture

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Age-specific considerations Fast desaturation

• Low FRC, high closing volume, highly compliant airways► atelectasis

• High oxygen consumption + can’t do forced inspiration ► increase R.R. ►high work of breathing

• Diaphragmatic breathing► easily fatigue (less type I muscle fibers)►fast desaturation

Page 6: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Age-specific considerations

• Cardiac output is rate dependent (can’t increase stroke volume)

• Immature baroreceptor reflex and limited ability to compensate for hypotension by increasing heart rate. They are more susceptible, therefore, to the cardiac depressant effects of volatile anesthetics (parasympathetic predominance)

• Immature hepatic function (drug dosing intervals &maintenance)

• Immature renal function (poor toleration of fluid restriction/overload)

Page 7: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

• High volume of distribution of drugs

• Temperature control (easily loose heat under GA) due to high surface area to body weight ratio, no shivering

• Competent nociceptive system (nonanalgesic practice is no longer accepted)

Age-specific considerations

Page 8: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Premedication

Atropine (10-20µ/kg IV, minimum 100µ) to counteract parasympathetic reflexes.

Pain (increments of morphine 10-20µ/kg IV up to 100µ/kg)

Page 9: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Monitoring

FiO2, ECG, NIBP, ETCO2, Pulse oximetry, Temperature

Direct BP (accurate, intravascular volume status e.g. undulations with ventilation and reduced upstroke of the BP curve in case of hypovolemia)

CVP (vasoactive drugs)

Urine output (1 ml/kg/h)

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How Long Pre-oxygenation?

60 seconds 6L/min (gives 80-90 seconds before desaturation) (Morrison JE et al: Pediatric Anaesthesia1998:8;293)

Inhalation VS Intravenous Induction?

IV access + hemodynamically stable→ STP 4-8mg/kg (prolonged emergence & postoperative apnea)- Propofol 3-3.5mg/kg

IV access + hemodynamically unstable → Ketamine 1.5-3mg/kg

Difficult IV access or compromised airway → Sevoflurane or halothane

Combined technique → (opioid + nondepolarizing MR + inhalation agent)

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LMA VS ETT?

LMA: less than 30-45 min

Size 1 ( 50% misplacement, NGT, small dose of MR, large dead space & hypercapnea, helpful for ex-premis with BPD)

ETT: longer surgeries

No awake intubation (very stressful/painful stimulus with suboptimal conditions)

Relaxation?

Succinyl choline (RSI) (higher doses than adults), large ECF volume

Nondepolarizing MR (similar doses as adults), sensitivity offset by large ECF

Deep inhalation anesthesia, disadvantages?

Page 12: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Technique?

•Oral Vs nasal? (lateral/prone/limited head access)

•Straight blade- go deeper then withdraw

•Level: term neonate (9cm oral/11cm nasal), 1 year 11-12cm

•Leak pressure? 20-25cmH2O, affected by head position& MR

•50% decrease in flow from size 3.5 to 3

•Non-cuffed/cuffed: 8y (upper abdominal & thoracic surgery, poor

lung compliance)

•After intubation → VCM (40cmH2O/15 sec) or TRIM (30cmH2O/10

sec)

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Spontaneous Vs controlled?

-Spontaneous: more than 6 mos, less than 30 min

Pressure Vs volume control?

-Pressure control: First few days, premature, respiratory distress or lung pathology

-Volume control: surgical manipulations interfere with ventilation

-Peep 3-5 is routine

“ Whatever the technique, an expired tidal volume & PIP should be tailored to the desired levels”

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Maintenance:

• Halothane/sevoflurane/isoflurane all depress baroreceptor reflex• Halothane depress the myocardium more• Halothane decrease the heart rate more

(Hypotension is treated by atropine & lowering halothane)• Sevo/Isoflurane decrease PVR more (treated by 5-10ml/kg fluid

bolus)• Nitrous oxide 60% decreases MAC of halothane, isoflurane &

sevoflurane by 60%, 40% & 25% respectively

• Narcotics: -Fentanyl 1-2µ/kg if regional block was done-Fentanyl based anesthesia for prolonged major surgery with postoperative ventilation

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“The use of light general volatile anesthetic with a central or peripheral nerve block has proved to be of great benefit in neonatal surgery”

Bosenberg AT et al, Pediatr Surg Int, 1992:7, 289

Larsson BA et al, Anesth Analg 1997:84, 501

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Intraoperative Volume Replacement

Hypovolemia with blood loss accounts for 12% of causes of cardiac

arrest in OR with almost half of it due to under estimation of blood

loss.*

*Anesthesia-Related Cardiac Arrest in Children: Update from the Pediatric Perioperative Cardiac Arrest Registry

Bananker et al, Anesthesia & Analgesia, August 2007

Page 17: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Assessment of dehydration

Mild

(50ml/kg)

Moderate

(100ml/kg)

Severe

(150ml/kg)

Wt loss%

Behavior

Thirst

Mucous memb.

Tears

Anterior fontanel

Skin turgor

Urine output

5

Normal

Slight

Normal

Normal

Flat

Normal

<2ml/kg/hr

10

Irritable

Moderate

Dry

+

+

+

<1ml/kg/hr

15

++irrit/lethargic

Intense

Parched

Absent

Sunken

Increased

<0.5ml/kg/hr

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Fluid & blood loss

Type of fluid? Dextrose? BSS?

Weighing swabs before it dries.

Intraoperative blood loss should be replaced with balanced salt solution (1:3), or colloid (1:1)

Estimated maximum allowable blood loss =

EBV x (Hctstarting – Hctacceptable)

Hctstarting

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Prevention of Heat Loss

Radiation

Evaporation

Conduction

Convection

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Prevention of Heat Loss

Room temp.: 76-78 F

Avoid unnecessary exposure & cover cotton wraps as much as possible

HME (active or passive) IVF: warm

Active warming mattress

Cover exposed viscera with warm wet towels

Incubator: keep plugged

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Emergence

Reversal of MR after spontaneous movement even with adequate time after last dose

Extubation:

Regular spontaneous breathing

Vigorous movements of all limbs

Gagging

Eye opening or pronounced grimacing

Stable hemodynamics & good oxygen saturation

Absence of significant hypothermia

Page 22: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Case-specific considerations Hydrocephalus

• Burr hole over a dural venous sinus

• Bowel injury (re-do)• Perforation of chest

wall/neck vessels/occipital bone

• Hemodynamic instability/arrhythmias (acute decompression)

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Craniosynostosis

Premature fusion of cranial suture → lack of growth perpendicularly & compensated overgrowth in normal areas affecting mental development &vision due to intracranial hypertension

Difficult airway if syndrome

Positioning (Supine → RAE or reinforced, Prone → nasal T. sutured to nasal septum with 4-0 nylon)

Blood loss (Donation, coag. Profile, 2 Ivs, A line)

Prolonged surgery & hypothermia

Venous air embolism

Raised ICP

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Encephalocele

Wet/soft covering

Avoid pressure

Antibiotics

Prone (nasal intubation)

Blood loss

Hypothermia

Latex – free procedure

Document spontaneous breathing postoperatively

Neural tube defect with variable neural dysfunction + Hydrocephalus + Arnold Chiari type II

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Myelomeningocele

Neural tube defect with variable neural dysfunction

+ Hydrocephalus + Arnold Chiari type II

Wet covering

Avoid pressure

Antibiotics

Prone (nasal intubation)

Blood loss

Hypothermia

Latex – free procedure

Page 26: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Neonatal Conditions Requiring SurgeriesAirway Obstruction

Inspiratory stridor with jugular &intercostal/subcostal retractions

-Bilateral choanal atresia

-Laryngomalacia

-Supraglottic papillomatosis

-Subglottic hemangioma

-Cystic hygroma

-The Pierre Robin Syndrome

Page 27: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Choanal atresia

OGTCHARGE Syndrome(Coloboma-Heart –Atresia-Retarded-Genital-Ear)

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Laryngomalacia

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Supraglottic Papillomatosis

Subglottic Hemangioma

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Cystic Hygroma

Cystic Hygroma( Recurrence)

Page 31: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

The Pierre Robin Syndrome

Typical Anesthestic Management of

a Neonate Presenting with Stridor:

ABG, chest x-ray

IV access, atropine, preoxygenation

Inhalation induction (deep)

CPAP

Smaller ETT or inhaled gases through side port of bronchoscope

Hydrocortisone 1-2 mg/kg

ICU or high dependency area for 12-24 h

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Neonatal Conditions Requiring SurgeriesAirway ObstructionCleft Lip/Palate

Echocardiography

Blood?

Atropine 10µ/kg

Difficult intubation

RAE tubes

Throat pack

Infra-orbital N. block

Extubation

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Page 34: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Thoracic SurgeriesEsophageal Atresia/TEF

1cm

Page 35: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Thoracic SurgeriesEsophageal Atresia/TEF

1:3000M:F 25:3First fed chocking, cyanosisCHD, VACTERL association 13%

Page 36: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Thoracic SurgeriesEsophageal Atresia/TEF

Management:

Head up

Continuous low suction on blind pouch

Echocardiography

Antibiotics

Vit K

Next day surgery

Page 37: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Thoracic SurgeriesCongenital Lobar Emphysema

Unilateral disease due to bronchomalacia, vascular anomaly, bronchial obstruction)

Present with respiratory distress & cyanosis with mediastinal shift

Coexisting CHD in 35%Anesthesia:

Spontaneous ventilation should be maintained with 100% oxygen + Ketamine + InotropesExpand lungs before closureIntercostal blockExtubate (spontaneous breathing)

Page 38: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Thoracic SurgeriesPatent Ductus Arteriosus

A disease of Prematurity with Lt to Rt shunt resulting in:

1- Pulmonary over-circulation, high load on lt side, high output cardiac failure

2- In severe cases, reversal of diastolic aortic blood flow in the descending aorta resulting in splanchnic hypoperfusion and NEC

Treatment:

Fluid restriction/diuretics (hypovolemia + hypokalemia)

Endomethacin (transient renal dysfunction, platelet dysfunction)

Ligation

Page 39: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Thoracic SurgeriesPatent Ductus Arteriosus

Preoperative: Echo (ht failure, hypovolemia)Head ultrasound (intracranial pathology)Routine labs (hypokalemia)1 unit PRBCs, 1 unit plasmaLast 24h urine output

Anesthesia:AtropineLow dose Sevoflurane + opioids + relaxantIf not intubated, nasal intubation is preferredTolerate desaturation for progress of surgery (limit is bradycardia)Treat hypotension with plasma expander + inotropeIntercostal block by surgeonNo immediate extubation

Page 40: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Abdominal Surgeries Congenital Diaphragmatic Hernia

1:5000M:F1:1.8

Resp. distressScaphoid abdomenShifted heart sounds

Bil. Pulmonary hypoplasiaHypoxia, hypercarbiaPulmonary HTN, shunting

Page 41: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Abdominal Surgeries Congenital Diaphragmatic Hernia

Management:

Gentle ventilation: Limiting PIP, Oscillator ( preductal SpO2> 90%)

Delayed repair (>100h) until medical stabilization

Reversal of duct shunting

Oxygenation Index < 40

PaCO2 < 40

Stable hemodynamics

Poor Predictors:

Overall survival 63%

Polyhydramnios

Immediate need for ventilation

Immature RBCs (intrauterine ↓COP)

Page 42: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Abdominal Surgeries Congenital Diaphragmatic Hernia

Anesthesia:

Working NGT

2 pulse oximeters

Atropine

Inhalation/ slow opioid

Treat hypotension with fluids/inotropes

Treat pneumothorax on the other side immediately

Treat the increased Rt to Lt shunt with fentanyl, higher FiO2, hyperventilation, correction of acidosis, Nitric oxide

Page 43: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Omphlocele

1:5000Hernial sac

CHD 30-40%Blood loss

HypothermiaHigh abdominal pressure

RSIInsensible water loss 10ml/kg/h

UOP

> 30 mmHg (Ventilation )

Page 44: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

GastroschisisMidline above umbilicusMidline above umbilicusOther abnormalities are rareOther abnormalities are rareNo hernial sacNo hernial sacCoverage Coverage Heating Heating I.V fluidsI.V fluidsAbdominal pressureAbdominal pressure

Page 45: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Gastrointestinal ObstructionPyloric Stenosis

Forceful projectile vomiting 4-6 weeks of age, palpable olive-like mass in epigastrium

Loss of hydrogen, chloride & potassium

Dehydration, electrolyte imbalance & acid-base disorder

Hypochloremic, hypokalemic alkalosis

Rehydration (do not accept base excess > +2)

Functioning NGT

RSI

No narcotics, local wound infiltration

Page 46: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Gastrointestinal Obstruction & Malrotation

Rehydration

Functioning NGT

Cross match PRBCs, FFP

RSI (ketamine)

If hypotension, give boluses of FFP, albumin 5% or PRBCs + dopamine

Untwisting malrotated gut releases vasoactive substances & lactic acid causing hypotension

Page 47: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Inguinal Hernial RepairHydroceleUndescended Testis

Wiener ES et al: Hernia survey of the Section on Surgery of the American Academy of Pediatrics. J Pediatr Surg 1996:31, 1166

70% GA (face mask or LMA) + Caudal epidural or spinal An.

15% Spinal anesthesia alone

11% Caudal anesthesia alone

Page 48: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Necrotizing Enterocolitis

It’s a disease of prematurity due to intestinal ischemia with secondary bacterial overgrowth → abdominal distention, increasing gastric aspirate, gastrointestinal bleeding & generalized sepsis.

Antibiotics

TPN

Volume replacement (Albumin 5%, FFP, PRBCs)

Functioning NGT

Check coagulation profile

Ecchocardiography

Chest x-ray for BPD

Inotropes (do not interrupt)

Maintain UOP (volume, Lasix 0.5 mg/kg)

Page 49: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Bladder Extrophy

Wet covering

Antibiotics

Blood loss

Hypothermia

Latex – free procedure

Postoperative immobility

Page 50: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.

Surgery on the NICU Graduate

First group: Uneventful prematurity → straight forward anesthesia

Second group: Ventilatory support-sepsis-PDA-IVH-NEC-multiple medications-BPD/chronic lung disease of the newborn-extubated with great difficulty.

The main concern is postoperative apnea until 6-12 Mon.

Goals: Avoid intubation/ventilation

Avoid postoperative apnea

Common surgeries:

1- Laser/cryosurgery for ROP → Face mask/LMA, avoid IV drugs in general

2- Inguinal hernia repair → awake caudal without any drug supplementation or combined with inhalation anesthesia via LMA

3- Circumcision → face mask with penile block

Page 51: Anesthesia During the First Year of Life Hany El-Zahaby, MD Dept. of Anesthesia, Ain Shams University.