Medical issues zuker

Medical issues zuker

Transcript

1. MEDICAL ISSUES IN PEDIATRIC ANESTHESIA DORA ZUKER, MD
2. RESPIRATORY ISSUES URI • Increased risk of Bronchospasm/intraop Hypoxemia/increased alv-art gradient/postop Hypoxemia • Decreased difussing capacity/increased closing volume • Intrapulmonary shunting • All aggravated by the GA effects on lung physiology/decreased FRC • Marked bronchial reactivity for up to 6 weeks • Bronchospasm/laryngospasm/stridor-specially subglottic edema if intubated
3. RESPIRATORY ISSUES ANESTHETIC DECISION MAKING • Postpone 1-2 w for uncomplicated URI– specially if RAD and intubation required for procedure • Postpone 4-6 weeks for lower airway involvement/ fever more than 38/ purulent discharge malaise and decreased apetite • Risk factors: <1yo/ asthma/prematurity/parental smoking/ ENT surgery • Use mask/LMA when possible • If ETT needed, use a size smaller and appropriate DEPTH of anesthesia • Ultimately, consider Psychosocial variables and use CLINICAL JUDGEMENT!!!
4. RESPIRATORY ISSUES ASTHMA • Most common disease of childhood in industrialized countries • Chronic inflammatory d/o of medium and small airways • Variable airway obstruction, partially or completely reversible/spontaneously or with treatment • Immune regulatory pathways: IL4/ Interferon G (control IGE Production) • Airway obstruction: smooth muscle spasm/mucosal edema/hypersecretion/mucous plugging • Physiopathologic changes: uneven distribution of ventilation/increased work of breathing/air trapping/V/Qmismatch/hyperinflation/hypoxemia/hypercapnia/resp failure
5. RESPIRATORY ISSUES RAD/ASTHMA • Strong association with allergies/familial predisposition/parental smoking • Gerd/ temperature changes/exercise/anxiety/URI/mechanical stimulation of the airway • Obesity is a proinflammatory state and independent factor • Severe viral bronchiolitis in infancy/ Respiratory failure in early age/ BPD/CDH/prematurity---rapid drop in saturation without large central airway obstruction (no audible wheezing)
6. RESPIRATORY ISSUES RAD • Pharmacology: steroids/LTinhibitors/Badrenergics/theophylline/cromolyn/anticholinergics • ICSs first line treatement with little effect on HPA axis except for high doses of fluticasone. Oral or parenteral steroids are indicated for acute exacerbations unresponsive to BD therapy • LT antagonists: LT mediate potent SM constriction/ their inhibition increase exhaled NO/ used as maintenance in mod to severe symptoms • B2 adrenergics: increased cAMP with SM relaxation/BD---short acting are indicated for intermittent episodes/acute exacerbations/prevention of exercise induced
7. RESPIRATORY ISSUES RAD • Methylxantines: inhibit adenosin induced BC ( not inhibiting PDE)/ decreases severity of persistent BS-night/narrow therapeutic index • Anticholinergics: ipatropium (slower onset/longer action) • Cromolyn Sodium: purely a PROPHYLACTIC agent, attenuating the response to exercise, allergens ( stabilizes mast cells)
8. RESPIRATORY ISSUE / RAD • Focus on assessment of severity/ baseline/exacerbations/recent illness/PE • Postpone 4-6 weeks if recent bad exacerbation/ URI and elective procedure • Premedication to avoid excitement/ nebulizer/avoid ETT/ lidocaine to blunt reflexes/ avoid ketorolac, morphine, desflurane, atracurium • Extubate DEEP or AWAKE/ BD before extubation, suction secretions thoroughly • Short course of CS (MP 1mg/kg daily) 48 hrs prior
9. RESPIRATORY ISSUES RAD/ INTRAOP BRONCHOSPASM • Confirm dx (exclude mainstem/mucus plug/kinked tube/anaphylaxis/CHF/foreign body/ light anesthesia) • Increase FiO2 • Deepen anesthetic • Administer B agonist-- Vital capacity maneuver with bag ventilation • Consider ketamine/lidocaine/atropine/IVsteroids (HC 2mg/Kg)/ epi • Modify vent to avoid barotrauma
10. BPD • Chr disease of lung parenchyma and small airways with Chr respiratory insufficiency in premiees • It follows ventilator lung induced injury and oxygen toxicity in babies with RDS • With recent changes in steroids and surfactant therapy, most BPD patients are born at 24-28 weeks • The “new BPD” is referred as O2 dependence for at least 28 postnatal days (prevalence is 20% of babies less than 1500gr) • Evaluation/severity are assessed at 36 weeks PCA and 56d after birth (based on FiO2 needs and vent support)
11. BPD/ Preanesth assessment • Mod to severe BPD --remains O2 dependent with or without CPAP or intubation, beyond 4 weeks of age • Persistent airway reactivity and lower airway obstruction (increased thicknesss of airway wall) • Growth failure/chr Hypoxia/Cor Pulmonale • Subglottic stenosis from prolonged intubation/Bronchomalacia/Tracheomalacia • Increased incidence of inguinal hernia (PPV) • Increased postop apnea
12. BPD Management • Obtain baseline SPO2/ may desaturate with the loss of HPV by GA • B2 agonists • Consider smaller ETT for subglottic stenosis • Observation for postop apnea
13. Cystic Fibrosis • Autosomal Recessive D/O caused by a defect in the CFTR gene • 1000 new cases per year in USA (30000 cases)/ most common inherited disorder in whites • Median life expectancy is 37 yo • CFTR regulates Cl and bicarb transport across epithelial cells and epithelial sodium channels (cAMP dependent) • CFTR dysfunction results in impaired exocrine function with abnormal electrolyte and fluid content in the epithelia of lung/pancreas/intestine/hepatobiliary/sweat gland/ vas deferens • Gold st is Cl sweat test, with greater than 60 mEq/lt as diagnostic
14. Cystic Fibrosis • Thick, hyperviscous mucus/ decreased mucous clearance • Prone to Chronic Pulm infection (SA, PA) -chronic inflammation- tissue destruction • Bronchiectasis /Pneumo tx/ fibrosis/ RHF • Pan sinusitis/nasal polyps • Enzyme def/ DM from pancreas destruction • Meconial ileus in NB • Intussuception • Liver failure/vit K def
15. Cystic Fibrosis • Consider preop pulm tests/ assess response to BD • Hydration status/ BS /coagulation /albumin levels • 50% have GERD - consider RSI • High risk of hemoptysis • Use heated and humidified gases/ avoid ketamine/suction thoroughly
16. Down Sd • 1 in 600-800 live births-life expectancy 60yo • 40% have CV anomalies (endocardial cushion defect/VSD/ASD/PDA/TOF • Disruption of airway patency (Hypotonia/ macroglossia/short neck /laryngomalacia) • Subglottic stenosis/ complete tracheal rings • C1-C2 subluxation (12-32%) • Hypothyroidism • Leukemia
17. Down Sd • Recommendation of x-rays between 3-5 yo to r/o atlantoaxial instability • PMH and PE : neck pain/limitation/upper motor dysf • If atlantodens interval greater than 5mm refer to neurosurgery eval • Keep head in neutral position as much as possible
18. Genetic Muscle D/O • Muscular Dystrophies---dissociation of contractile force from muscle to surrounding connective tissue causing electromechanical dissociation plus instability in cell mb integrity • Myotonic Sd---affects transmission along the muscle mb (abn Na/ K/Ca/Cl channels). Prolonged depol with prolonged contraction • Mitochondrial Myopathies---involves CNS and muscle/ lack of ATP causes weakness and wasting • Myasthenic SD---affect transmission of AP from motor neuron to muscle cell (ach)
19. Myasthenic Sd • Resp compromise from weakened resp or upper airway muscles • Minimize MR/ assume increase sensitivity • Often there is resistance to succ • Watch for fatigue in postop period • Tourniquette release may exacerbate symptoms
20. Myotonias • Family of channelopaties • Prolonged depolarization/ prolonged contraction/masseter rigidity • Might be precipitated by succ or anticholinesterases • Risk of hyperkalemic response with succ • No progression or dystrophic component • Might be precipitated by stress/ cold and pain/ anticholinesterase (not relieved by NDMR) • No true association with MH- GA gases could be used • Episodes of myotonia could be relieved by procainamide/ quinine and GA
21. Mitochondrial Disease • Under stress conditions ATP levels may not meet demands making these pts very vulnerable during the periop period • Shivering from hypothermia represents the greatest threat • Lactic acidosis occurs due to stress • Maintenance fluids with glucose to avoid anaerobic metabolism/do not administer LR/ avoid long fasting periods- monitor glycemia and lactic acidosis, particularly if pt is on a ketogenic diet • Avoid anemia and tourniquettes • Primary complications are resp failure/myocardial and conduction issues/ dysphagia • Use lower doses of GA ,analgesics, sedatives, MR
22. Mithochondrial Disease Propofol affects Mithochondrial metabolism by at least 4 mechanisms The strongest effect is the inhibition of long chain acylcarnitine esters This is the mechanism implicated in propofol infusion Sd. Limited boluses have been well tolerated LA such as ropi and lidocaine should be prefered over bupi Remifentanyl and dex have been proven useful plus NSAIDS Succ is contraindicated due to the risk of Hyperkalemia and Myolisis
23. Muscular Dystrophy • Full cardiology eval with DMD and BMD within 3 months • Pulmonary testing before surgery • RSI due to dysphagia and decreased gastric motility • Avoid cardiac depressants • Prepare for RI postoperatively • Risk of hyperkalemia and Rhabdomyolisis with succ (contraindicated) • Avoid triggering agents---Rhabdomyolisis with inhaled agents (not MH)
24. Muscular Dystrophy/ Duchenne’s/ Becker’s • Duchenne is an x linked d/o that results in lack of dystrophin • It progresses to wheelchair dependence by the second decade of life • Profound muscle weakness/Resp failure/cardiomyopathy/conduction defects/occ mild MR • Becker’s is same mutation but less global
25. Metabolic Diseases • Primary diseases of metabolism that lead to chronically weak muscles, prone to damage when exposed to high metabolis stress • McArdle/ King-Denborough/Brody/Schwartz-Jampel • Use of non triggering agents- MH risk!!! • Prolonged observation postop for recurrent weakness
26. Cerebral Palsy • Static Encephalopathy--nonprogressive d/o of posture and movement • Poor muscle control/ weakness/spasticity • Epilepsy/ speech-vision-intellect involvement • Etiology: prematurity /antenatal insult • Multiple orthopedic procedures are required
27. Cerebral Palsy • Preop ---focus on neurologic/ pulmonary / GI issues/ malnutrition • GERD/delayed emptying • Chr lung disease---restrictive (from scoliosis) with RAD component • OSA/ neurogenic laryngomalacia/ decreased pharynx tone • Increased risk of sedated induced hypoxia • latex allergy
28. Cerebral Palsy • Extreme care with positioning • Avoid drugs that could facilitate seizures • Most anesthetic agents are safe/ lower MAC • Increased sensitivity to succ no hyperkalemia • Resistant to NDMR and rapid recovery • Pain management is crucial
29. Sickle Cell Disease Substitution of Valine for Glutamic Acid in abnormal B chains of HB S 8% of AA have sickle cell trait (Hb A and S) Homozygous only produce Hb S Bothof the above have a positivedex screen Hb S is less stable and less soluble - rapid denaturation, with RBC damage and rigidity and pathological adherenceand damage to endothelium
30. Sickle Cell Disease Clinical presentation arises from intermittent vaso-occlusive crises Infection and surgical stress are triggering events Dactilytis/ bone and organ infarction/Acute and ChrPain/ACS- fat emboli from necrotic bone marrow/ TIA/ stroke /priapism/ splenic sequestration with schock/aplastic crises/ cholelithiasis-cholcystitis Risk of drug addiction
31. Sickle Cell Disease Prophilactic preop RBC transfusions decrease the periop complications- decrease Hb S to less than 30% or increase Hb to 10g/dl Maintain adequate oxygenation/ thermoregulation/ hydration/ acid - base balance Avoid surgical tourniquettes Pain control is crucial