bài giảng dành cho sinh viên y khoa, bác sĩ, sau đại học , ĐH Y DƯỢC TP HCM PaCO2 > 45 mmHg & pH < 7.35: Res acidosis (inadequate VA). Etiology: Central nervous system Neuromuscular disorders Chest wall abnormalities Airway diseases Parenchymal diseases
IMPROVE PaCO2 Bs Phùng Nguyễn Thế Nguyên FACTORS AFFECT PaCO2 PaCO2 VCO2 VA = VE - VD (CO2 production) VT f ti te Equaton to change - PaCO2 known x VE known= PaCO2 desired x VE desired - PaCO2 known x VT known= PaCO2 desired x VT desired - PaCO2 known x f known= PaCO2 desired x f desired Res acidosis - PaCO2 > 45 mmHg & pH < 7.35: Res acidosis (inadequate VA) - Etiology: • Central nervous system • Neuromuscular disorders • Chest wall abnormalities • Airway diseases • Parenchymal diseases Child with MV (PC) - Set pressure to obtain targeted VT - Adjust rate - Increase Ti if it is short - 90 kg PC: ABG pH 7,31 PaCO2 59, IP 10 (vt 600 ml), PEEP 0, F 10; PaCO2 desired 40 mHg - Vt desired = vt 59/ 40 = 600 x 59/40 = 885 ml - Cs = Vt/p (Pplateau – PEEP) = 600/10 = 60 ml/cmH20 - p desired = 885/60 = 14.75 15 cmH20 Resp alkalosis - PaCO2 < 35 mmHg & pH > 7.35: Res acidosis (inadequate VA) - Etiology: • Central nervous system: encepalitis, meningitis • Parenchymal diseases • Hypoxia with compensatory hyperventilation • MV • Anxiety • Metabolic problem: sepsis, hepatic diseases Child with MV (PC) - Set pressure to obtain targeted VT - Adjust rate - Increase Ti if it is short - 90 kg PC: ABG pH 7,51 PaCO2 29, IP 20 (vt 900 ml), PEEP 0, F 12; PaCO2 desired 40 mHg - Vt desired = vt 59/ 40 = 900 x 29/40 = 635 ml - Cs = Vt/p (Pplateau – PEEP) = 900/20 = 45 ml/cmH20 - p desired = 635/45 = 14 15 cmH20 Res alkalosis during spontaneuos efforts - 25 year old, 80 kg, VC 12 breath/min, Vt ml/kg - RR real 16 breath/min, Ph 7,5 PaCO2 30 manage? - Drcrease f? decrease Vt? - SIMV - PS - Sedation: agitation, Work of breathing, dysynchrony - Head trauma: may be can not corrected Res acidosis & metabolic alkalosis Protocol for implementation of permissive hypercapnia - Hypercapnia progressively in increments of 10 mmHg to max 80 mmHg/day - If hypercapnia > 80 mmHg, progress more slowly Airway clearance during MV - Suction catheter diameter: • French = circumference of the tube = d x 3,1416 Diameter: ẵ -2/3 ET diameter • Suction catheter (Fr) = 1,5 diameter of ET - Suction pressure: • Adult: (-) 100-120 (max 150 mmHg) • Child: (-) 80 -100 (max 125 mmHg) • Infant: (-) 60-100 (max 100 mmHg) Instilling saline - 3-5 ml normal or half saline - Risk: dislodging bacteria - Does not thin secretions - Worse airway obstruction - Reduce oxygenation - Irritaion to the airways, so cough episodes and bronchospam - Prudent: Selective and routine Thank you! ... AFFECT PaCO2 PaCO2 VCO2 VA = VE - VD (CO2 production) VT f ti te Equaton to change - PaCO2 known x VE known= PaCO2 desired x VE desired - PaCO2 known x VT known= PaCO2 desired x VT desired - PaCO2. .. x VT known= PaCO2 desired x VT desired - PaCO2 known x f known= PaCO2 desired x f desired Res acidosis - PaCO2 > 45 mmHg & pH < 7. 35: Res acidosis (inadequate VA) - Etiology: • Central nervous... targeted VT - Adjust rate - Increase Ti if it is short - 90 kg PC: ABG pH 7, 31 PaCO2 59, IP 10 (vt 600 ml), PEEP 0, F 10; PaCO2 desired 40 mHg - Vt desired = vt 59/ 40 = 600 x 59/40 = 885 ml - Cs