Past History - เป็นบุตรคนเดียว คลอดปกติครบกำหนด น้ำหนักแรกคลอด 3,420 กรัม หลังคลอดพัฒนาการปกติ ได้วัคซีนครบตามกำหนด - เป็น G6PD deficiency Family History - มีทวดเป็นเบาหวาน
Physical Examination Vital Signs : PR 108, BP 100/55, T 37˚c,RR=32 BW =23.5,Height = 97 cm. General appearance : A Thai boy look obesity mild dyspnea,no cyanosis,noisy breathing HEENT : not pale conjunctiva,no icteric sclera no cyanosis,no neck vein engorged tonsil Rt. gr.3, Lt. gr.4 LN not palpable Heart : PMI at 5 th intercostal space,MCL regular rhythm,normal s1,s2,no murmur
Lungs : inspiratory stridor rhonchi and wheezing both lungs Abdomen : fatty contour,active bowel sound no hepatosplenomegaly,not tender Extremities : no edema Airway evaluation : Interincisor gap 3 cm Thyromental distance 5 cm Mallapati class III no craniofacial anormally no micronagthia no retronagthia no loose of teeth
Lab Investigation 1. CBC Hb = 11.9, Hct = 35.2, WBC = 9,700 Plt. = 460, U/A pH 7, sp.gr. = 1.015,alb.-ve,sugar -ve WBC -ve, RBC -ve 3. BUN = 19, cr = 0.6, Na = 140, K = 4.0, Cl = 104, Total CO2 = 24, BS = PT = 9.8 ( 11.3), PTT = 30.8 (33.8)
Obstructive sleep apnea syndrome Definitions # Sleep apnea = cessation of air flow at the mouth and nose for at least 10 s during sleep # Central sleep apnea = no airflow at the nose and mouth occurs and there is no respiratory movement # Obstructive sleep apnea = absence of airflow at the mouth and nose despite respiratory movement
# Hypopnea = partial upper airway obstruction during sleep causing at least a 50% reduction in airflow with respiratory movement # Mixed sleep apnea = a period of central apnea followed by an obstructive apnea episode Epidemiology of SAS - Sleep apnea syndrome is a common disorder, the estimate prevalence in middle-aged adult population = 1-4% - In children = 0.7-2%,Thailand = 0.69%
- Most common in children age 2-5 years old. Pathogenesis & Pathophysiology - During normal respiration-->genioglossus & geniohyoid muscles act as the main muscle groups in maintainina pharyngeal airway patency. - During inspiration-->tone in these muscles counteracting intraluminal pharyngeal pressure generate by the respiratory pump muscles.
- During sleep--> Force of dilatory muscles negative intraluminal pressure exceeding inspiratory collapse of the upper airway - Obstructive sleep apnea results from a narrowing of the airway and occurs as a consequence of an anatomical reduction in the upper airway or incoordination of upper airway dilatory muscle activity.
3. Opposition of the lateral pharyngeal wall 4. Circular closure of the pharynx - When OSA occurs,the site of the obstruction can be anywhere from the nasopharynx to the supraglottis 1. Anterioposterior displacement of the tongue against the posterior pharynx 2. Posterior displacement of the soft palate by the tongue against the posterior pharynx
Decreased Upper Airway Muscle Activity Upper Airway Narrowing Obstructive Hypoventilation And Apnea Hypoxemia Hypercapnia Decreased CO 2 Increased O 2 Relief of Obstruction Restoration of Airflow Increase Upper Airway Muscle Activity Arousal from Sleep Sleep Onset Increased Ventilatory Effort Muscle Weakness Small Airway Enlarged Tonsils and Adenoids Obesity Sedation Anesthesia
Predisposing factors to OSA Anatomic factors that narrow the upper airway # Adenotonsillar hypertrophy # Trisomy 21 # Other genetic or crainofacial syndromes associated with - Midface hypoplasia - Small nasopharynx - Micrognathia or retrognathia - Choanal atresia or stenosis - Macroglossia - Cleft palate # Obesity # Nasal obstruction
Plan of anesthesia 1. Preanesthetic period - evaluation - preparation - premedication 2. Intraoperative management - induction - intubation - maintenance of anesthesia - recovery 3. Post anesthetic care
Preanesthetic evaluation 1.Patients history & physical examination --> to detemine the ease of mask ventilation and tracheal intubation 2.Lab investigation --> CBC & Coagulation parameter --> CXR --> EKG 3.Medication --> antibiotic,diuretic --> premedication - sedative drug - antisialagogue - preemptive drug - prophylactic antiemetic
Induction 1. Inhalation induction - smooth transition from spontaneous to assist ventilation-->ease to management of a difficult airway - effects of anesthesia reversible if difficult in maintaining airway - The use of inhalational agents in patient with pulmonary hypertension has been reported to lower pulmonary arterial pressure - un pleasant for the child and result in coughing & laryngospasm,especially if anticholinergic premedication has not been given
- Most inhalation agents have a myocardial depressant effect in the high concentrations required for induction - Sevoflurane has smoother and more rapid inhalational induction and faster emergence compare with halothane - Nitrous oxide has been reported to produce a rise in pulmonary artery pressure
Intravenous induction - rapid,does not produce an excitation phase and reduces the likelihood of vomiting and laryngospasm - may be complete loss of upper airway with an inability to ventilate the lungs - if the upper airway becomes obstruct during induction can relieve by jaw manipulation, the use of an oral or nasal pharygeal airway or the use of CPAP - All anesthetic drug should be titrated to just the desire effect,prefer using short acting
Intubation - Tracheal intubation is the prefer option for adenotonsillectomy and in children with associate craniofacial abnormalities this can proove difficult - Intubation can be facilitated by using high concentrations of inhalation agents in the spontaneously breathing child. - Alternatively,a muscle relaxant can be used to facilitate intubation
@ suxamethonium => short acting => cardiac nondepo. => longer onset,duration =>prolong ventilate=>regur. => if complete airway obstruct. Difficult to reverse - Awake intubation may be difficult in uncooperative child. - Blind nasal intubation is an alternative technique in skill hands.
- The laryngeal mask airway has been used successfully in many cases of failed intubation and its elective use in ENT surgery is becoming widespread. LMA ---> no aspiration of blood --> one study found recovery to be significant better,with less airway obstruction when compare with tracheal tube --> extra vigilance because of the danger if it dislodge
Maintenance anesthesia - Spontaneous or controlled ventilation should be used for adenotonsillectomy is controversial - In the USA advocate control ventilation. - In the UK advocate spontaneous ventilation - Nondepolarising Muscle relaxant should be used intermediate acting than longer acting - The use of opioids during anethesia may result in respiratory depression,especially in the postoperative period. ---> should be limited and short-acting opioids use
- The use of nitrous oxide and volatile agents may be beneficial to decrease the amount of opioids required to maintain anesthesia. - When pulmonary hypertension is present, nitrous oxide may cause a marked increase in pulmonary vascular resistance and pulmonary arterial pressure Extubation - Perform only in the fully awake alert patient. - Respiratory monitoring is imperative after extubation,and all equipment and personnel necessary for airway management must be immediately available.
- Extubation in the lateral position,with slight head down tilt,will ensure safe drainage of blood if rebleeding should occur Postoperative management -Positioning--> sitting posture in OSAS+obesity --> tonsil position in tonsillectomy -Oxygen therapy prevent early episode desat.-->add 28% O 2 concern that O 2 may increase apnea duration ---> CO 2 retention -Pain -systemic opioids use with extreme caution -NSAIDs ---> caution
CPAP therapy - Nasal CPAP may also be used to maintain pharyngeal patency in patients demonstrating recurrent apnea after extubation. Bleeding Postoperative nausea and vomiting Acute postoperative pulmonary edema