Pediatric Anesthesia Practice available in Paperback
- ISBN-10:
- 0521709377
- ISBN-13:
- 9780521709378
- Pub. Date:
- 07/30/2007
- Publisher:
- Cambridge University Press
- ISBN-10:
- 0521709377
- ISBN-13:
- 9780521709378
- Pub. Date:
- 07/30/2007
- Publisher:
- Cambridge University Press
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Product Details
| ISBN-13: | 9780521709378 |
|---|---|
| Publisher: | Cambridge University Press |
| Publication date: | 07/30/2007 |
| Series: | Cambridge Pocket Clinicians |
| Pages: | 230 |
| Product dimensions: | 4.92(w) x 7.01(h) x 0.39(d) |
Read an Excerpt
Cambridge University Press
978-0-521-70937-8 - Pediatric Anesthesia Practice - Edited by Ronald S. Litman, DO. and FAAP
Excerpt
PART ONE
Coexisting Diseases
ANTERIOR MEDIASTINAL MASS
PAUL STRICKER, MD
BACKGROUND
■ Most common cause: lymphoma
■ Suspect in pts presenting for cervical mass biopsy.
■ Other dxs: neuroblastoma, teratoma, germ cell tumor, bronchogenic cyst, foregut cyst, lymphangioma, mesenchymal tumor
■ Symptoms due to compression of anatomic structures
■ Symptoms worse when supine
■ Symptoms may be relieved by lateral or upright position.
■ Clinical: cough, hoarseness, dyspnea, wheezing, orthopnea, stridor, chest pain, syncope, SVC syndrome, tracheal deviation, retractions
■ Asymptomatic or nonspecific: fever, fatigue, weight loss
PREOPERATIVE ASSESSMENT
■ Preoperative radiation tx may interfere with accuratehistologic dx & optimal tx regimens.
■ Physical exam: orthopnea, tracheal deviation, jugular venous distention, wheezing, retractions, unilateral decreased breath sounds
■ CXR: tracheal deviation, tracheal compression, abnormal cardiothymic silhouette
■ Echo: direct compression of cardiac chambers and/or great vessels, pericardial effusion
■ CT: assess severity & location of tracheal compression
■ Preop sedation: avoid or give in monitored setting
■ Antisialagogue (e.g., glycopyrrolate) useful
■ Obtain Ⅳ access prior to OR, ideally in lower extremity.
■ Correct preexisting dehydration or hypovolemia.
INTRAOPERATIVE MANAGEMENT
■ Potential catastrophic airway or cardiovascular collapse during induction of anesthesia
■ Monitors: std; A-line for great vessel or cardiac compression
■ All sized endotracheal tubes and rigid bronch immed avail in OR
■ For severe cases, ECMO or CPB stand-by
■ Liberal fluid administration if great vessel/cardiac compression
■ Position: semi-recumbent, sitting, or lateral
■ Local anesthesia without sedation is safest strategy, but not feasible for small children.
■ Most important to avoid airway/CV collapse: MAINTAIN SPONTANEOUS VENTILATION
■ Mask or LMA OK
■ Ketamine allows spontaneous ventilation & provides sympathetic stimulation.
■ Sevoflurane or Ⅳ agents OK if titrated to avoid apnea
■ Paralysis & controlled ventilation OK for mild cases, but no way to predict safety
■ Tx of airway obstruction: positive pressure, change position to lateral, sitting or prone if CV arrest
■ Rigid bronch may bypass airway obstruction.
■ ECMO or CPB as lifesaving measure
POSTOPERATIVE CONCERNS
■ Airway obstruction may occur postop during recovery.
■ Recover in lateral or semi-recumbent position.
■ Titrate opioids: avoid apnea.
ASTHMA
SANJAY M. BHANANKER, MD, FRCA
BACKGROUND
■ Incidence: 7–19%
■ Cause: chronic inflammation & mucus hypersecretion of lower airways
■ Symptoms: airway hyperreactivity with variable degrees of airflow obstruction
■ Strong association with atopy and allergy
PREOPERATIVE ASSESSMENT
■ Note severity and frequency of acute exacerbations, precipitating factors.
■ Elicit history of drug therapy, especially systemic steroids, to gauge severity.
■ If acute exacerbation or URI within 6 wks, consider postponing elective surgery.
■ Premed: inhaled beta-2 agonist, steroids (daily meds)
■ Anxiolysis with oral midazolam; fear, stress, excitement, or hyperventilation can provoke acute attack
INTRAOPERATIVE MANAGEMENT
■ Mask induction with sevoflurane or IV induction with propofol or ketamine
■ Minimize airway manipulation.
■ Face mask or LMA preferred
■ Avoid histamine-releasing drugs: thiopental, morphine, mivacurium, succinylcholine.
■ All volatile anesthetic drugs, propofol and ketamine are bronchodilators.
■ Administer stress dose of Ⅳ hydrocortisone if pt on oral prednisone.
■ If intraoperative wheezing occurs:
i. Rule out kinked ET tube or bronchial intubation
ii. Give 100% oxygen, deepen anesthesia with propofol, ketamine, or volatile agents
iii. IV lidocaine 0.5–1 mg/kg bolus
iv. Use low respiratory rate and long expiratory time to avoid intrinsic PEEP
v. Nebulized beta-2 agonist such as albuterol via ET tube or LMA
POSTOPERATIVE CONCERNS
■ Deep extubation for pts with uncomplicated airway avoids risk of bronchospasm during emergence.
■ If awake extubation planned, nebulized prophylactic beta-2 agonist, IV lidocaine
■ Humidify supplemental oxygen, ensure adequate systemic hydration: dry anesthetic gases and O2 are potential triggers for asthma.
ATRIAL SEPTAL DEFECT (ASD)
LUIS M. ZABALA, MD
DISEASE CHARACTERISTICS
■ Definition: opening in the atrial septum except patent foramen ovale (PFO)
■ 7–10% of all CHD
■ Incidence of PFO in adults: 25%
■ Pathophys: extra load on right side of the heart (L to R shunt)
■ Magnitude of shunt relates to size of defect, ventricular compliance, & pulmonary artery pressures.
■ L to R shunt: RA & RV enlargement
■ Pulmonary vascular changes develop from long-standing volume overload.
■ Majority of pts are asymptomatic during childhood.
■ In adulthood, extra load on RV leads to CHF, failure to thrive, recurrent respiratory infections, & symptomatic supraventricular dysrhythmias.
■ Pulm htn in up to 13% of nonoperated pts
PREOPERATIVE ASSESSMENT
■ CXR: RA & RV enlargement.
■ ECG: right or left axis deviation possible; incomplete RBBB from stretch in right bundle of His
■ Echo: secundum or primum defect; mitral regurg from anterior leaflet cleft.
■ Ventricular dysfunction possible from long-standing volume overload
■ Cardiology consultation for symptomatic pts
■ Premed: PO midazolam (0.5 mg/kg) or PO pentobarbital (4 mg/kg)
■ Caution with oversedation & hypoventilation: can worsen PVR & RV fn
INTRAOPERATIVE MANAGEMENT
■ Std monitors during noncardiac surgery or transcatheter closure of ASD
■ Symptomatic or complicated pts may require additional monitoring.
■ Intracardiac surgical repair requires extracorporeal circulation and arterial invasive monitoring.
■ Central venous monitoring at discretion of anesthesiologist
■ Transesophageal echo helpful to assess de-airing of left heart & adequacy of surgical repair
■ Inhalation induction generally safe
■ Inhalation agents, narcotics, muscle relaxants, and/or re-gional anesthesia usually well tolerated
■ De-bubble all Ⅳ lines.
■ Atrial dysrhythmias common in adult unrepaired pt
POSTOPERATIVE CONCERNS
■ Immediate or early tracheal extubation possible following uncomplicated surgical repair of ASD
■ Pts with good ventricular function prior to repair do not require inotropic support.
■ Dopamine 3–5 mcg/kg/min usually sufficient for ventricular dysfunction
■ Pulm htn may occur in older pts after ASD repair; use aggressive ventilation & milrinone.
■ Pts with unrepaired ASD undergoing noncardiac surgery should be monitored closely for CHF due to volume overload or atrial dysrhythmias.
■ Titrate analgesia to pain control without vent depression.
CEREBRAL PALSY
NATHALIA JIMENEZ, MD, MPH
BACKGROUND
■ Definition: static motor encephalopathy
■ Secondary to perinatal or early childhood (<2 yr) CNS injury
■ Incidence 2.4 per 1,000 live births
■ 4 categories: spastic (quadriplegia, diplegia, hemiplegia), dyskinetic (dystonia, athetosis, chorea), ataxic (tremor, loss of balance, speech involvement), mixed
■ Assoc with developmental delay, visual & cognitive abnormalities, & motor problems possible with normal cognitive function
■ Require multiple surgeries: mainly orthopedic (spinal fusion and release of limb contractures)
■ Bulbar motor dysfunction predisposes to GE reflux, swallowing disorders & loss of airway protective mechanisms leading to chronic aspiration, recurrent pneumonia, hyperactive airways
■ Seizures in 30%: continue anticonvulsant on day of surgery & reinstitute early in postop period
■ Baclofen used for muscle spasms, can cause urinary retention & leg weakness
■ Abrupt baclofen withdrawal may cause seizures; overdose assoc with decreased consciousness & hypotension
PREOPERATIVE ASSESSMENT
■ Premedication tolerated in most pts; reduce dose or avoid if hypotonic
■ Anticholinergic will decrease secretions in pts with bulbar dysfunction.
INTRAOPERATIVE MANAGEMENT
■ Contractures make positioning and Ⅳ access difficult.
■ Impaired temp regulation due to hypothalamic dysfunction
■ Monitor temperature and use warming measures.
■ Inhalation induction safe unless severe reflux
■ Increased sensitivity of succinylcholine: use only in emergency situations
■ Decreased sensitivity to non-depolarizing muscle relaxants: requires higher doses
■ Increased sensitivity to inhaled anesthetics and opioids: use lower doses
■ Awake extubation in OR
POSTOPERATIVE CONCERNS
■ Pain assessment difficult due to inability to communicate: use modified behavioral pain scales
■ Regional techniques for postop analgesia recommended
■ Low-dose benzodiazepines (diazepam) to prevent/treat muscle spasms
COARCTATION OF THE AORTA
SCOTT D. MARKOWITZ, MD
BACKGROUND
■ Prevalence: 8% of pts with CHD
■ Coexisting bicuspid aortic valve, arch hypoplasia, other heart defects
■ Hypertension is usually present pre-repair and may persist postop.
■ May be repaired with balloon dilation or surgical correction end-to-end anastomosis or subclavian flap arterioplasty
■ Residual or recurrent coarct may occur early or late: eval by right arm vs. leg BP & Doppler echo.
PREOPERATIVE ASSESSMENT
■ ECG & echo: ventricular hypertrophy/dysfunction, valve dysfunction, residual coarct
■ BP measurements in all extremities, identification of previous recurrent laryngeal nerve injury
■ Antihypertensive regimen assessed and instructions for day of surgery medication administration given
INTRAOPERATIVE MANAGEMENT
■ SBE prophylaxis even after repair
■ If pre-repair: BP monitoring on pre-coarct artery (usually right arm except in cases of aberrant subclavian artery)
■ If post-repair: monitors accurate in any extremity, except if residual coarct
■ Left arm BP unreliable after subclavian flap repair
■ Caution with intercostal blocks if intercostal arteries dilated
POSTOPERATIVE CONSIDERATIONS
■ Std pain management: opioids & NSAIDs
■ Monitor for arrhythmias; resume antihypertensive therapy as appropriate.
CRANIOFACIAL SYNDROMES
SALLY E. RAMPERSAD, MB FRCA
BACKGROUND
■ Premature fusion of one or more skull sutures
■ Major component of several congenital syndromes: Crouzon, Saethe-Chotzen, Pfeiffer, Carpenter, Aperts
PREOPERATIVE ASSESSMENT
■ Previous anesthetic records: airway issues & management
■ Examine for obstructing mass (cystic hygroma, large tongue in Beckwith-Wiedemann syndrome; micrognathia/retrognathia in Pierre Robin); limited mouth opening, limited neck mobility, facial asymmetry (Goldenhars).
■ Abnl ear form & position indicate other facial anomalies.
■ Inform family of potential airway complications.
■ Snoring, daytime somnolence, or hx of stridor may indicate significant airway obstruction.
■ Cleft lip/palate are part of other syndromes (eg, CHARGE, trisomy 18, velocardiofacial syndrome).
■ Associated anomalies: ear, renal, CV
■ Avoid pre-op sedation in pts with potential airway obstruction, or administer with anesthesiologist present.
■ PO or Ⅳ atropine (0.02 mg/kg) as antisialagogue/vagolytic
■ Prepare different sizes of facemasks (air-filled cushion for asymmetric face), LMAs, oral & naso-pharyngeal airways, endotracheal tubes, fiberoptic bronchoscopes, stylets.
© Cambridge University Press