Mechanical Ventilation in Pediatric Practice

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Mechanical Ventilation in
Pediatric Practice
π‘∑ ‡√◊Õß√Õß√—µπå
‡§√◊ËÕߙ૬À“¬„®‡ªìπÕÿª°√≥å∑’Ë¡’§«“¡ ”§—≠„π
°“√™à«¬‡À≈◊ÕºŸâªÉ«¬‡¥Á°¿“«–«‘°ƒµ∑’Ë¡’ªí≠À“ respiratory failure „πÕ¥’µ¡’°“√„™â‡§√◊ÕË ß™à«¬À“¬„®™π‘¥ negative pressure ventilation À√◊Õ iron lungs ‡æ◊ËÕ√—°…“
ºŸªâ «É ¬∑’‡Ë ªìπ‚√§‚ª≈‘‚Õ µàÕ¡“‰¥â¡°’ “√æ—≤π“Õÿª°√≥凪ìπ
™π‘¥ positive pressure ventilation ·≈–¡’°“√æ—≤π“
«‘∏°’ “√∑”ß“π¢Õ߇§√◊ÕË ßÕ¬à“ßµàÕ‡π◊ÕË ß‡æ◊ÕË „ÀâªØ‘ ¡— æ—π∏å
√–À«à“ߺŸâªÉ«¬°—∫‡§√◊ËÕߙ૬À“¬„®¡’§«“¡ ¡¥ÿ≈°—π
‡ªÑ“À¡“¬À≈—°¢Õß°“√„™â‡§√◊ËÕߙ૬À“¬„®‚¥¬
∑—Ë«‰ª¡’Õ¬Ÿà 3 ª√–°“√1,2
1. ·°â‰¢§«“¡º‘¥ª°µ‘¢Õß°“√·≈°‡ª≈’¬Ë π°ä“´„Àâ
Õ¬Ÿ„à π‡°≥±å∑πË’ “à æÕ„® ‡æ◊ÕË „Àâ¡’ adequate arterial oxygenation ·≈– effective alveolar ventilation
2. ª≈¥¿“√–ß“π (unloading) ¢Õß°≈â“¡‡π◊ÕÈ ™à«¬
°“√À“¬„® ‡æ◊ËÕ≈¥ work of breathing
3. ªÑÕß°—π¿“«–·∑√°´âÕπ∑’ÕË “®‡°‘¥¢÷πÈ ®“°“√„™â
‡§√◊ÕË ß™à«¬À“¬„®√–À«à“ß∑’√Ë Õ„Àâ欓∏‘ ¿“æ∑’ªË Õ¥¥’¢πÈ÷
·π«∑“ߪؑ∫—µ‘‡æ◊ËÕ„Àâ∫√√≈ÿ‡ªÑ“À¡“¬∑—Èß “¡
ª√–°“√¥—ß°≈à“«„πºŸâªÉ«¬‡¥Á°®”‡ªìπ∑’Ë∑’¡·æ∑¬å·≈–
欓∫“≈µâÕß¡’§«“¡√Ÿâ§«“¡‡¢â“„®„π‡√◊ËÕß°“√„™â‡§√◊ËÕß
™à«¬À“¬„®‡ªìπÕ¬à“ߥ’ ´÷Ëßªí®®ÿ∫—π‡§√◊ËÕߙ૬À“¬„®∑’Ë
„™â°π— ∑—«Ë ‰ª„πºŸªâ «É ¬‡¥Á°§◊Õ™π‘¥ positive pressure ventilation
Positive Pressure Ventilation1,4
§◊Õ °“√∑”ß“π¢Õ߇§√◊ÕË ß™à«¬À“¬„®∑’„Ë À⧫“¡¥—π
∫«° (positive pressure) ‡¢â“‰ª„π√–∫∫°“√À“¬„® ¢Õß
ºŸâªÉ«¬µ≈Õ¥∑—Èß respiratory cycle ‚¥¬¡’§à“ proximal
airway pressure ¡“°°«à“ alveolar pressure ·≈–
‡æ◊ËÕ„À⇢Ⓞ®≈—°…≥–°“√∑”ß“π¢Õ߇§√◊ËÕߙ૬À“¬„®
ºŸ„⠙⮖µâÕ߇¢â“„®°≈‰°°“√∑”ß“π¢Õ߇§√◊ÕË ß™à«¬À“¬„®
∑’·Ë ∫àßÕÕ°‡ªìπ™à«ßʵ“¡≈”¥—∫°“√À“¬„®‡¢â“·≈–À“¬„®
ÕÕ° ´÷Ëß·∫àßÕÕ°‡ªìπ 4 phases ‰¥â·°à
1. Expiratory to inspiratory phase
2. Inspiratory phase
3. Inspiratory to expiratory phase
4. Expiratory phase
1. Expiratory to inspiratory phase (trigger variable) ‡ªìπ™à«ß∑’Ë ”§—≠‡æ√“–‡ªìπ™à«ß∑’Ë
°√–µÿâπ„À⇰‘¥°“√∑”ß“π¢Õ߇§√◊ËÕߙ૬À“¬„®‡æ◊ËÕ‡√‘Ë¡
°“√À“¬„®‡¢â“ ‚¥¬‡§√◊ËÕß®–«—¥°“√‡ª≈’ˬπ·ª≈ߢÕߧà“
pressure, volume, flow À√◊Õ time „π√–∫∫·≈–„™â
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§à“„¥§à“Àπ÷ßË ‡ªìπµ—«°”Àπ¥°“√‡√‘¡Ë °“√À“¬„®‡¢â“ ∑’πË ¬‘ ¡
„™â‰¥â·°à pressure, flow ·≈– time trigger
2. Inspiratory phase (limit variable) ‡ªìπ
™à«ß∑’ˇ§√◊ËÕߙ૬À“¬„®®–„™â volume, pressure À√◊Õ
flow §à“„¥§à“Àπ÷Ë߇ªìπµ—«°”Àπ¥„π°“√™à«¬ºŸâªÉ«¬¢≥–
À“¬„®‡¢â“ ·≈–®”°—¥‰«â‰¡à„À⇰‘π§à“∑’˺Ÿâ„™â‰¥âµ—È߉«â·≈â«
(preset value) µ≈Õ¥™à«ß°“√À“¬„®‡¢â“
3. Inspiratory to expiratory phase (cycle
variable) ‡ªìπ™à«ß∑’°Ë ”Àπ¥°“√ ‘πÈ ÿ¥¢Õß™à«ßÀ“¬„®‡¢â“
‡¡◊ËÕ§à“„¥§à“Àπ÷Ëߥ—ßµàÕ‰ªπ’È ‰¥â·°à pressure cycled,
volume cycled, flow cycled À√◊Õ time cycled ∂÷ß®ÿ¥
∑’˺Ÿâ„™âµ—È߉«âÀ√◊Õ‡§√◊ËÕߙ૬À“¬„®°”À𥉫â
4. Expiratory phase (baseline variable) ‡ªìπ
™à«ß∑’‡Ë §√◊ÕË ß™à«¬À“¬„®„™â§«∫§ÿ¡°“√À“¬„®ÕÕ°À√◊Õ™à«ß
‡«≈“°“√À“¬„®ÕÕ° ‚¥¬∑—«Ë ‰ª®– “¡“√∂°”Àπ¥ pressure ·≈– expiratory time ‡™àπ °“√µ—Èß positive endexpiratory pressure (PEEP) ‡æ◊Ëՙ૬‡æ‘Ë¡§à“ functional residual capacity (FRC) ∑”„ÀâªÕ¥¢ÕߺŸâªÉ«¬
∑’Ë¡’ªí≠À“°“√§ß ¿“æ¢≥–À“¬„®ÕÕ° ‡™àπ hyaline
membrane disease (HMD) À√◊Õ acute respiratory
distress syndrome (ARDS) „Àâ§ß ¿“æ„°≈â°∫— §à“ª°µ‘
À√◊Õ°“√°”Àπ¥„Àâ expiratory time (Te) π“π°«à“
inspiratory time (Ti) ‡æ◊ËÕ„Àâ¡’‡«≈“æÕ∑’Ë≈¡„π∂ÿß≈¡
·≈–À≈Õ¥≈¡®–∂Ÿ°¢—∫ÕÕ°‰ª‰¥âÀ¡¥ªÑÕß°—π°“√‡°‘¥
air trapping (hyperinflation)
‡¡◊ÕË √Ÿ°â ≈‰°°“√∑”ß“π·≈â« ºŸ„⠙⮖µâÕ߇≈◊Õ°‡§√◊ÕË ß
™à«¬À“¬„® ·≈–«‘∏’°“√™à«¬À“¬„® (modes) ∑’ˇ¢â“°—∫
欓∏‘ √’√«‘∑¬“¢Õß‚√§∑’ºË ªŸâ «É ¬‡ªìπ ‚¥¬°“√°“√æ‘®“√≥“
Õߧåª√–°Õ∫¥—ßµàÕ‰ªπ’È
°“√µ—ßÈ ‡§√◊ÕË ß™à«¬À“¬„®„Àâ‡À¡“– ¡°—∫欓∏‘ √’√«‘∑¬“
¢Õß‚√§1
°“√µ—ßÈ ‡§√◊ÕË ß™à«¬À“¬„®®–µâÕß„™â§«“¡√Ÿæâ πÈ◊ ∞“π
„π‡√◊ÕË ßªØ‘ ¡— æ—π∏å√–À«à“ß√–∫∫À“¬„®°—∫√–∫∫‰À≈‡«’¬π
‚≈À‘µ ´÷ËߺŸâªÉ«¬‡¥Á°∑’ËÕ¬Ÿà„π¿“«–«‘°ƒµ·≈–µâÕß„™â‡§√◊ËÕß
™à«¬À“¬„®Õ“®·∫àßÕÕ°‰¥â‡ªìπ 2 °≈ÿࡵ“¡≈—°…≥–∑“ß
√’√«‘∑¬“¢Õß√–∫∫‰À≈‡«’¬π‚≈À‘µ ‰¥â·°à
1. °≈ÿà¡ Preload-dependent
‡ªìπ°≈ÿࡺŸâªÉ«¬∑’Ë¡’ cardiac performance ¢÷Èπ
°—∫ªí®®—¬¢Õß preload ‡ªìπÀ≈—°§◊Õ À“°‡æ‘Ë¡À√◊Õ≈¥
ª√‘¡“µ√¢Õ߇≈◊Õ¥„πÀ—«„®ÀâÕß≈à“ߴ⓬°àÕπ∑’Ë®–∫’∫µ—«
(left ventricular end-diastolic volume À√◊Õ LVEDV)
®– àߺ≈„Àâ cardiac output (CO) ‡æ‘Ë¡¢÷ÈπÀ√◊Õ≈¥≈ß
‡™àπ‡¥’¬«°—π ‡π◊ËÕß®“° LVEDV Õ¬Ÿà„π ascending limb
¢Õß Starling curve ºŸªâ «É ¬°≈ÿ¡à π’‡È ªìπºŸªâ «É ¬ à«π„À≠à∑‡’Ë ¢â“
√—∫°“√√—°…“„πÀÕºŸªâ «É ¬«‘°ƒµ ·≈–®–‰¥â√∫— ª√–‚¬™π宓°
°“√≈¥º≈°√–∑∫∑’‰Ë ¡à¥µ’ Õà √–∫∫‰À≈‡«’¬π‚≈À‘µ∑’ÕË “®‡°‘¥
¢÷Èπ¢≥–°“√„™â‡§√◊ËÕߙ૬À“¬„®„Àâ‡À≈◊ÕπâÕ¬∑’Ë ÿ¥
2. °≈ÿà¡ Afterload-dependent
‡ªìπ°≈ÿࡺŸâªÉ«¬∑’Ë¡’ cardiac performance ¢÷Èπ
°—∫ªí®®—¬¢Õß afterload ‡ªìπÀ≈—°§◊Õ À“°∑”„Àâ·√ßµâ“π
∑“π°“√∫’∫µ—«¢ÕßÀ—«„®ÀâÕß≈à“ߴ⓬ (LV afterload) ≈¥
≈ß®–∑”„Àâ CO ‡æ‘Ë¡¢÷Èπ À√◊Õ LV afterload ‡æ‘Ë¡¢÷Èπ
®–∑”„Àâ CO ≈¥≈ß ºŸâªÉ«¬°≈ÿà¡π’È¡—°®–‡ªìπºŸâªÉ«¬∑’Ë¡’
ªí≠À“°≈â“¡‡π◊ÕÈ À—«„®∑”Àπâ“∑’∫Ë °æ√àÕß ‚¥¬Õ“®¡’ “‡Àµÿ
®“° ‚√§À—«„®∑’ˇªìπ·µà°”‡π‘¥ (congenital heart disease) À√◊Õ¡’ myocardial dysfunction ®“°¿“«– sepsis À√◊Õ septic shock ´÷Ëß¡—°¡’ªí≠À“ fluid overload
Õ¬Ÿà·≈â« ¥—ßπ—ÈπºŸâªÉ«¬®–‰¥â√—∫ª√–‚¬™π宓°º≈°√–∑∫∑’Ë
¥’µàÕ√–∫∫‰À≈‡«’¬π‚≈À‘µ¢≥–°“√„™â‡§√◊ËÕߙ૬À“¬„®
°“√≈¥º≈°√–∑∫∑’Ë ‰¡à¥µ’ Õà √–∫∫‰À≈‡«’¬π‚≈À‘µ (detrimental hemodynamic effects)
‡π◊ÕË ß®“°°“√„™â‡§√◊ÕË ß™à«¬À“¬„®∑”„Àâ·√ߥ—π„π
∑√«ßÕ° (intrathoracic pressure À√◊Õ ITP) ¡’§à“‡ªìπ
∫«°µ≈Õ¥∑—ßÈ respiratory cycle ®÷ß¡’º≈∑”„Àâ systemic
venous return ¢ÕߺŸâªÉ«¬≈¥≈ß ∑”„Àâ CO ≈¥≈߇™àπ
‡¥’¬«°—π ¥—ßπ—πÈ °“√µ—ßÈ ‡§√◊ÕË ß™à«¬À“¬„®‡æ◊ÕË ≈¥º≈°√–∑∫
∑’ˉ¡à¥’µàÕ√–∫∫‰À≈‡«’¬π‚≈À‘µ ¡’·π«∑“ߪؑ∫—µ‘¥—ßπ’È
1. °“√µ—È߇§√◊ËÕߙ૬À“¬„®‡æ◊ËÕªÑÕß°—π°“√‡°‘¥
Mechanical Ventilation in Pediatric Practice, π‘∑ ‡√◊Õß√Õß√—µπå 67
hyperinflation ¢Õߪե ‚¥¬
- °“√µ—Èß PEEP „Àâ§à“µË” ÿ¥‡∑à“∑’Ë®”‡ªìπ
- ª√—∫ À√◊Õ §Õ¬µ√«® Õ∫ Te „Àâ‡À¡“–
¡‰¡à —Èπ®π‡°‘π‰ª ·≈–√–«—ß°“√‡°‘¥ dynamic hyperinflation (‡ªìπº≈®“°°“√„™â Te ∑’Ë —Èπ‡°‘π‰ª àߺ≈„Àâ
¡’≈¡§â“ß„πªÕ¥¡“°¢÷Èπ ·≈–º≈∑’˵“¡¡“§◊Õ ·√ߥ—π„π
∂ÿß≈¡®– Ÿß°«à“ airway opening pressure ∑”„À⇰‘¥
auto-PEEP) ºŸªâ «É ¬®–À“¬„®≈”∫“°·≈–„™âæ≈—ßß“π¡“°
¢÷Èπ
2. °“√§«∫§ÿ¡ peak inspiratory pressure (PIP)
·≈– mean airway pressure (MAP) ‰¡à„Àâ ߟ ‡°‘𧫓¡
®”‡ªìπ ‚¥¬
- ≈¥ bronchomotor tone „πºŸâªÉ«¬∑’Ë¡’
ªí≠À“¥â«¬°“√„™â¬“¢¬“¬À≈Õ¥≈¡
- ≈¥ inspiratory flow rate ´÷Ëß®–™à«¬≈¥
PIP 䴉
- ‡≈◊Õ°„™â mode ∑’˺ŸâªÉ«¬ “¡“√∂À“¬„®‰¥â
‡Õß (spontaneous breathing) ®–™à«¬≈¥ PIP ‰¥â
3. °“√§«∫§ÿ¡„À⺟âªÉ«¬¡’°“√‡ª≈’ˬπ·ª≈ߢÕß
ITP πâÕ¬∑’Ë ÿ¥
4. °“√≈¥ work of breathing (WOB) „π¢≥–∑’Ë
¬—ߧ߄À⺟âªÉ«¬‡√‘Ë¡µâπ°“√À“¬„®‡Õß ‚¥¬
- ª√—∫ flow pattern „À⇢⓰—∫ºŸªâ «É ¬¡“°∑’ Ë ¥ÿ
‚¥¬°“√‡≈◊Õ°„™â mode ∑’˺ŸâªÉ«¬§«∫§ÿ¡ flow rate ‰¥â
‡Õß ‡™àπ pressure support mode ´÷Ëß¡’¢âÕ¬°‡«âπ°√≥’
∑’ªË Õ¥¡’§«“¡º‘¥ª°µ‘Õ¬à“ß√ÿπ·√ß ®”‡ªìπµâÕß„Àâ°“√™à«¬
À“¬„®‡µÁ¡∑’Ë (full support)
- ≈¥ trigger threshold ”À√—∫ assisted
breath ªí®®ÿ∫π— „π‡§√◊ÕË ß√ÿπà „À¡à®–·π–π”„Àâ„™â flow trigger ”À√—∫ºŸâªÉ«¬‡¥Á°‡≈Á°
°“√ à߇ √‘¡º≈°√–∑∫∑’¥Ë µ’ Õà √–∫∫‰À≈‡«’¬π‚≈À‘µ (beneficial hemodynamic effects)
‡π◊ÕË ß®“°°“√„™â‡§√◊ÕË ß™à«¬À“¬„®∑”„Àâ ITP ¡’§“à
‡ªìπ∫«°µ≈Õ¥∑—Èß respiratory cycle ¥—ßπ—Èπ®÷ß¡’º≈™à«¬
≈¥ LV afterload °“√µ—È߇§√◊ËÕߙ૬À“¬„®‡æ◊ËÕ à߇ √‘¡
„À⇰‘¥º≈°√–∑∫∑’Ë¥’µàÕ°“√∑”ß“π¢Õß√–∫∫‰À≈‡«’¬π
‚≈À‘µ ®÷ß¡’ à«π ”§—≠„π°“√√—°…“ºŸâªÉ«¬ ‚¥¬¡’·π«∑“ß
ªØ‘∫—µ‘¥—ßπ’È
1. °“√·°â‰¢„Àâª√‘¡“µ√ªÕ¥„°≈⇧’¬ß§à“ FRC
ª°µ‘ ‡æ◊ËÕ∑’Ë®–„Àâ pulmonary vascular resistance
(PVR) ≈¥µË”∑’Ë ÿ¥‰¥â ‚¥¬
- ªÑÕß°—π°“√‡°‘¥ dynamic hyperinflation
‚¥¬‡©æ“–ºŸªâ «É ¬„π°≈ÿ¡à obstructive lung disease ‡™àπ
meconium aspiration syndrome, acute bronchiolitis, acute exacerbation of asthma ‡ªìπµâπ ‚¥¬°“√
ª√—∫„Àâ Te ‰¡à —Èπ®π‡°‘π‰ª
- „™â PEEP ∑’ˇÀ¡“– ¡„π°√≥’¢Õß diffuse
parenchymal lung disease ‡™àπ HMD, ARDS ‡ªìπµâπ
2. §«∫§ÿ¡„Àâ ITP ¡’°“√‡ª≈’ˬπ·ª≈ßπâÕ¬∑’Ë ÿ¥
‡æ◊ËÕªÑÕß°—π‰¡à„Àâ LV afterload Ÿß¢÷Èπ ‚¥¬
- ≈¥ trigger threshold ”À√—∫ assisted
breath ·π–π”„Àâ„™â flow trigger
- æ‘®“√≥“„™â PEEP ™à«¬‡æ◊ËÕ‰¡à„Àâ ITP ≈¥
µË”≈ß¡“°„π°√≥’ºŸâªÉ«¬∑’ˇ°‘¥ auto-PEEP
- ≈¥ extrinsic airway resistance ¢Õß respiratory circuit ‰¥â·°à À≈’°‡≈’ˬ߰“√„™â∑àՙ૬À“¬„®
¢π“¥∑’ˇ≈Á°‡°‘π‰ª À√◊Õ °“√‡≈◊Õ° mode ∑’Ë®–™à«¬≈¥
WOB ¢ÕߺŸâªÉ«¬∑’ËÀ“¬„®ºà“π∑àՙ૬À“¬„®¢π“¥‡≈Á°
‡™àπ pressure support mode
3. °“√ª√—∫‡æ‘¡Ë setting ¢Õ߇§√◊ÕË ß™à«¬À“¬„®·°à
ºŸâªÉ«¬∑’Ë¡’ intravascular volume ‡æ’¬ßæÕ·≈⫇∑à“π—Èπ
·≈–æ‘®“√≥“„™â inotropic drugs ‡¡◊ËÕ¡’¢âÕ∫àß™’È
Terminology1,3,5
°“√„™â‡§√◊ËÕߙ૬À“¬„®¡’§” (terminology) ∑’Ë
ºŸâ„™â®–µâÕß√Ÿâ·≈–‡¢â“„®°àÕπ¥—ßµàÕ‰ªπ’È
1. Tidal volume (TV) §◊Õ ª√‘¡“µ√¢Õß≈¡∑’Ë
ºŸâªÉ«¬À“¬„®‡¢â“À√◊ÕÕÕ°µàÕ°“√À“¬„®Àπ÷Ëߧ√—Èß
2. FRC §◊Õ §à“ª√‘¡“µ√¢Õß≈¡„πªÕ¥¢≥–∑’Ë
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ºŸâªÉ«¬À“¬„®ÕÕ°ª°µ‘
3. Flow rate §◊Õ Õ—µ√“°“√‰À≈¢Õß°ä“´∑’˪√—∫
µ—Èß‚¥¬ºŸâ„™âÀ√◊Õ°”À𥮓° mode ¢Õ߇§√◊ËÕß ·≈–¡’Õ¬Ÿà
2 ·∫∫‰¥â·°à continuous flow ·≈– demand flow ‚¥¬∑’Ë
continuous flow À¡“¬∂÷ß ‡§√◊ËÕߙ૬À“¬„®®–„Àâ°ä“´
‡¢â“ ventilator circuit µ≈Õ¥∑—ßÈ respiratory cycle à«π
demand flow À¡“¬∂÷ß ‡§√◊ËÕߙ૬À“¬„®®–„Àâ°ä“´‡¢â“
ventilator circuit ‡©æ“–™à«ßÀ“¬„®‡¢â“·≈–ºŸªâ «É ¬®–µâÕß
„™â inspiratory effort ‡ªî¥ demand valve ‡æ◊ËÕ„Àâ°ä“´
‰À≈‡¢â“ ventilator circuit
4. Flow pattern §◊Õ √Ÿª·∫∫Õ—µ√“°“√‰À≈¢Õß
°ä“´ÕÕ°®“°‡§√◊ËÕߙ૬À“¬„® ´÷ËߥŸ‰¥â®“° flow wave
form ∑’Ë¡’≈—°…≥–‡¥àπ‰¥â·°à constant flow, decelerating flow ·≈– sinusoidal flow (sine wave)
5. Respiratory rate (RR) §◊Õ Õ—µ√“°“√À“¬„®
°“√ª√—∫µ—Èߢ÷Èπ°—∫§à“ TV ∑’Ë°”Àπ¥ 欓∏‘ ¿“æ¢Õß
√–∫∫À“¬„® §à“ PaCO2 ∑’µË Õâ ß°“√ ·≈–Õ—µ√“°“√À“¬„®
ª°µ‘¢ÕߺŸâªÉ«¬
6. Ti and Te §◊Õ ‡«≈“∑’˺Ÿâ„™â‡§√◊ËÕß°”Àπ¥„Àâ
≈¡‡¢â“À√◊ÕÕÕ°®“°ªÕ¥¢ÕߺŸªâ «É ¬ ®–ª√—∫æ√âÕ¡§à“ I:E
ratio §à“∑’Ë°”Àπ¥®–‰¥â¡“®“°°“√§”π«≥¢Õß ¡°“√
compliance X resistance ‡√’¬°«à“ time constant
¥—ßπ—Èπ∂⓺ŸâªÉ«¬‡ªìπ‚√§∑’Ë¡’ resistance Ÿß¢÷È𠇙àπ
asthma, acute bronchiolitis ºŸâ„™â®–µâÕߪ√—∫§à“ Te
„À⬓«¢÷Èπ ·µà∂⓺ŸâªÉ«¬‡ªìπ‚√§∑’Ë¡’ compliance ≈¥≈ß
‡™àπ HMD, ARDS ºŸâ„™â®– “¡“√∂ª√—∫„™â§à“ Ti ·≈–/
À√◊Õ Te „Àâ —Èπ°«à“ª°µ‘‰¥â ‚¥¬ª°µ‘§à“ Ti, Te ®–
ª√–¡“≥ 3-5 ‡∑à“¢Õß time constant ‡™àπ ∑“√°ª°µ‘
compliance = 0.004 L/cmH2O, resistance = 30
cmH2O/L/s §à“ time constant = 0.12 sec à«π°“√
µ—Èß§à“ I:E ratio Õ“»—¬À≈—°∑’Ë«à“ª°µ‘°“√À“¬„®ÕÕ°
µâÕß°“√‡«≈“¡“°°«à“ °“√À“¬„®‡¢â“ ®÷ß¡—°µ—ßÈ I:E ratio
Õ¬Ÿà√–À«à“ß 1 : 2 À√◊Õ 1 : 3
7. PIP §◊Õ §à“ Ÿß ÿ¥¢Õß airway pressure „π
™à«ß°“√À“¬„®‡¢â“¢≥–„™â‡§√◊ÕË ß™à«¬À“¬„® °“√ª√—∫µ—ßÈ
§à“∑’ˇÀ¡“– ¡¥Ÿ‰¥â®“°°“√‡§≈◊ËÕπ¢÷Èπ≈ߢÕß∑√«ßÕ°
ºŸªâ «É ¬ À√◊Õ®“°°“√øí߇ ’¬ßÀ“¬„® ¢Õß≈¡∑’‡Ë ¢â“ÕÕ° (air
entry) ‚¥¬∑—Ë«‰ª§à“ PIP ®–‡ª≈’ˬπ·ª≈߉ªµ“¡ flow
rate ·≈– Ti ‡™àπ ∂â“ flow rate Ÿß¢÷Èπ PIP ®– Ÿß¢÷Èπ
‡ªìπ —¥ à«π°—π‰ª
8. PEEP §◊Õ §à“µË” ÿ¥¢Õß airway pressure
„π™à«ßÀ“¬„®ÕÕ° „πºŸªâ «É ¬∑’µË Õâ ß„ à∑Õà ™à«¬À“¬„® physiologic PEEP ®–À“¬‰ª ¥—ßπ—Èπ‡«≈“ª√—∫µ—È߇§√◊ËÕߙ૬
À“¬„®µ“¡ª°µ‘®–ª√—∫„Àâ¡’§à“ PEEP Õ¬Ÿàª√–¡“≥ 2-3
cmH2O ‡æ◊ËÕªÑÕß°—π microatelectasis à«π„π°√≥’∑’Ë
欓∏‘ ¿“æ¢Õߪե‡ªìπ™π‘¥∑’¡Ë ’ lung compliance µË”
°“√„™â PEEP ∑’ Ë ßŸ ¢÷πÈ ®–∑”„Àâ°“√·≈°‡ª≈’¬Ë π°ä“´¥’¬ß‘Ë ¢÷πÈ
°“√‡≈◊Õ°„™â PEEP ∑’ˇÀ¡“– ¡ (optimum PEEP) ®–
“¡“√∂À≈’°‡≈’ˬ߰“√„™â FiO2 > 0.6 ‚¥¬∑’˺ŸâªÉ«¬¡’§à“
PaO2 ·≈– SaO2 ¡“°°«à“ 60 mmHg ·≈– 90% µ“¡
≈”¥—∫ ´÷Ë߉¡à∑”„Àâ CO, urine output ≈¥≈ß·≈–‰¡à‡°‘¥
barotrauma ‡™àπ pneumothorax (¢âÕ·π–π” „π‡¥Á°
∑“√°À√◊Õ‡¥Á°‡≈Á°‰¡à§«√µ—Èß PEEP Ÿß‡°‘π 8 cmH2O
∂Ⓡªìπ‡¥Á°‚µ‰¡à§«√µ—Èß PEEP Ÿß‡°‘π 15 cmH2O)
9. MAP (mean airway pressure) §◊Õ §à“‡©≈’¬Ë
¢Õߧ«“¡¥—π„π√–∫∫À“¬„®®“°“√„™â‡§√◊ËÕߙ૬À“¬„®
´÷Ë߇°‘¥„π™à«ßÀ“¬„®‡¢â“ °“√‡æ‘Ë¡¢÷Èπ¢Õß MAP ®–
—¡æ—π∏å°—∫°“√‡æ‘Ë¡§à“ PEEP, PIP, I:E ratio À√◊Õ
inspiratory flow °“√ª√—∫ setting ‡æ◊ËÕ‡æ‘Ë¡ MAP ®–
∑”„Àâ oxygenation ¢ÕߺŸâªÉ«¬¥’¢÷Èπ ‡π◊ËÕß®“°°“√≈¥
≈ߢÕß®”π«π∂ÿß≈¡∑’Ë·ø∫·≈–™à«¬„Àâ “√πÈ”∑’ËÕ¬Ÿà„π∂ÿß
≈¡°√–®“¬ÕÕ°‰ª∫√‘‡«≥ interstitial tissues ¥—ßπ—πÈ ºŸ„â ™â
®÷ߧ«√‡≈◊Õ°∑’Ë®–ª√—∫ setting ‡æ◊ËÕ‡æ‘Ë¡§à“ MAP °—∫
ºŸªâ «É ¬∑’¡Ë ¿’ “«– hypoxemia ´÷ßË ‰¡àµÕ∫ πÕßµàÕ°“√‡æ‘¡Ë
FiO2 > 0.5
10. FiO2 (fractional inspire oxygen concentration) §◊Õ §à“§«“¡‡¢â¡¢âπ¢ÕßÕÕ°´‘‡®π„π°ä“´ ∑’„Ë Àâ°∫—
ºŸâªÉ«¬ ‡æ◊Ëՙ૬·°â‰¢¿“«– hypoxemia ·≈–¬—ß∑”Àπâ“
∑’ˇªìπ pulmonary vasodilator ∑’Ë¥’ ‚¥¬∑—Ë«‰ª„π√–¬–
‡√‘¡Ë µâπ¢Õß°“√„™â‡§√◊ÕË ß™à«¬À“¬„®¡—°®–ª√—∫ FiO2 = 1
Mechanical Ventilation in Pediatric Practice, π‘∑ ‡√◊Õß√Õß√—µπå 69
µàÕ¡“À≈—ß®“°∑’ÕË “°“√¢ÕߺŸªâ «É ¬¥’¢πÈ÷ ®÷ߧàÕ¬Ê ª√—∫„Àâ
FiO2 ≈¥≈ߧ√—Èß≈– 0.05-0.1„Àâ‡À≈◊ÕπâÕ¬ ÿ¥‡∑à“∑’Ë®–
ª√—∫‰¥â ‡æ√“–∂⓺Ÿªâ «É ¬‰¥â FiO2 > 0.5 π“πÊ ®–∑”„À⇰‘¥
oxygen toxicity
11. Sensitivity §◊Õ §à“¢Õß trigger threshold
”À√—∫ assisted breath ·µà≈–§√—Èß §«√ª√—∫µ—Èß„Àâ
‡À¡“– ¡°—∫∑àՙ૬À“¬„®·≈– circuit ‡æ◊ËÕ‰¡à„À⺟âªÉ«¬
µâÕß„™â·√ß¡“°‡°‘π‰ª ‚¥¬∑—Ë«‰ª∂â“„™â pressure trigger ¡—°µ—È߉«âª√–¡“≥ (-1)-(-2 ) cmH2O À√◊Õ‡§√◊ËÕß∑’Ë
¡’ flow trigger ¡—°®–µ—È߉«âª√–¡“≥ 1-3 L/min. ¢âÕ
§«√√–«—ß∂⓵—Èß sensitivity µË”‡°‘π‰ª®–∑”„À⇰‘¥
autocycling
12. PaO2 §◊Õ §à“§«“¡¥—π¢Õß°ä“´ÕÕ°´‘‡®π„π
‡≈◊Õ¥·¥ß
13. PaCO2 §◊Õ §à“§«“¡¥—π¢Õß°ä“´§“√å∫Õπ
‰¥ÕÕ°‰´¥å„π‡≈◊Õ¥·¥ß
14. SpO2 §◊Õ §à“ oxygen saturation ¢Õß
Œ’‚¡‚°≈∫‘π„π‡≈◊Õ¥·¥ß∑’Ë«—¥®“° pulse oximetry
15. Compliance §◊Õ °“√·¢Áߢ÷πÈ (stiffness) À√◊Õ
¬◊¥À¬ÿàπ (distensibility) ¢Õߪե·≈–ºπ—ß∑√«ßÕ°
§”π«≥‰¥â®“° —¥ à«π°“√‡ª≈’¬Ë π·ª≈ߢÕߪ√‘¡“µ√ªÕ¥
(volume) µàÕ°“√‡ª≈’ˬπ·ª≈ߢÕß·√ߥ—π„π∑√«ßÕ°
(pressure)
16. Resistance §◊Õ º≈√«¡¢Õß·√ßµâ“π∑“πµàÕ
°“√‰À≈¢Õß°ä“´∑’‡Ë °‘¥¢÷πÈ „π∑“߇¥‘πÀ“¬„® ·≈– à«π‡π◊ÕÈ
‡¬◊ËÕ¢Õߪե·≈–ºπ—ß∑√«ßÕ°
Mode µà“ßÊ ¢Õß°“√™à«¬À“¬„®
«‘∏÷°“√™à«¬À“¬„®·∫à߇ªìπ™π‘¥µà“ßÊ ‰¥â¥—ßπ’È 1-5
- Controlled mechanical ventilation (CMV)
‡ªìπ«‘∏°’ “√™à«¬À“¬„®∑’‡Ë §√◊ÕË ß™à«¬À“¬„®∑”Àπâ“∑’·Ë ∑π
ºŸªâ «É ¬∑—ßÈ À¡¥ ºŸ„⠙⮖‡ªìπ§π°”Àπ¥§à“ TV, RR, Ti ·≈–
flow waveform
- Assisted mechanical ventilation (AMV)
‡ªìπ«‘∏’°“√™à«¬À“¬„®∑’ˇ§√◊ËÕߙ૬À“¬„®®–∑”Àπâ“∑’Ë
·∑πºŸâªÉ«¬ ·µà«‘∏’π’È°“√À“¬„®¢ÕߺŸâªÉ«¬®–°√–µÿâπ„Àâ
‡§√◊ÕË ß∑”ß“π ºŸ„⠙⮖‡ªìπ§π°”Àπ¥§à“ TV, Ti, ·≈– flow
waveform ‡À¡◊Õπ°—∫°“√„™â CMV µà“ß°—π∑’ËÕ—µ√“°“√
À“¬„®‡ªìπ¢ÕߺŸâªÉ«¬
- Assist-control ventilation (A/C) ‡ªìπ«‘∏’
°“√™à«¬À“¬„®∑’‡Ë §√◊ÕË ß™à«¬À“¬„®®–∂Ÿ°°√–µÿπâ ‚¥¬°“√
À“¬„®¢ÕߺŸâªÉ«¬∫“ß à«πÀ√◊Õ∑—ÈßÀ¡¥ ¢÷Èπ°—∫Õ—µ√“°“√
À“¬„®¢ÕߺŸªâ «É ¬·≈–Õ—µ√“À“¬„®∑’µË ß—È ‰«â„Àâ°∫— ‡§√◊ÕË ß™à«¬
À“¬„® ‡™àπ ∂â“Õ—µ√“°“√À“¬„®¢ÕߺŸâªÉ«¬ Ÿß°«à“Õ—µ√“
À“¬„®¢Õ߇§√◊ËÕߙ૬À“¬„® ‡§√◊ËÕߙ૬À“¬„®°Á®–∂Ÿ°
°√–µÿâπ°“√∑”ß“π‚¥¬ºŸâªÉ«¬‡Õß∑—ÈßÀ¡¥ ‡ªìπ°“√º ¡
º “π°“√∑”ß“π√–À«à“ß CMV ·≈– AMV ∂⓺ŸâªÉ«¬‰¡à
À“¬„®‡Õß„π‡«≈“∑’Ë°”Àπ¥ ‡§√◊ËÕß°Á®–™à«¬À“¬„®¥â«¬
Õ—µ√“∑’˵—È߉«â (backup rate) °“√™à«¬À“¬„®«‘∏’π’È®–∑”
‚¥¬‡§√◊ËÕߙ૬À“¬„®∑—ÈßÀ¡¥ (full support) ºŸâªÉ«¬®–
ÕÕ°·√߇撬߰√–µÿâπ„À⇧√◊ËÕß∑”ß“π ´÷Ëߪ√‘¡“≥ß“π
(WOB) ®–¢÷Èπ°—∫ sensitivity, peak inspiratory flow
·≈– respiratory drive ¢ÕߺŸâªÉ«¬‡Õß °“√µ—Èß inspiratory flow rate ®÷ß¡’§«“¡ ”§—≠¡“° §«√„Àâ‡æ’¬ßæÕ
°—∫ flow demand ¢ÕߺŸâªÉ«¬ ∂â“ flow rate ‰¡àæÕ
ºŸªâ «É ¬®–µâÕß‡æ‘¡Ë ·√ß„π°“√À“¬„®¡“°¢÷πÈ ‚¥¬∑—«Ë ‰ª§à“
flow demand ®–¢÷Èπ°—∫ minute ventilation ¢ÕߺŸâªÉ«¬
- Intermittent mandatory ventilation (IMV)
‡ªìπ«‘∏’°“√™à«¬À“¬„®‚¥¬„À⇧√◊ËÕߙ૬À“¬„®∑”ß“π
≈—∫°—∫®—ßÀ«–°“√À“¬„®‡Õß (spontaneous breathing)
¢ÕߺŸªâ «É ¬ «‘∏π’ πÈ’ ¬‘ ¡„™â ”À√—∫°“√‡µ√’¬¡ºŸªâ «É ¬„π°“√∑’Ë
®–À¬ÿ¥„™â‡§√◊ÕË ß™à«¬À“¬„® ‚¥¬°“√∑’≈Ë ¥Õ—µ√“°“√∑”ß“π
¢Õ߇§√◊ÕË ß™à«¬À“¬„®≈߇√◊ÕË ¬Ê „π¢≥–∑’ªË ≈àÕ¬„À⺪⟠«É ¬
À“¬„®‡Õ߇æ‘Ë¡¢÷Èπ ªí≠À“¢Õß IMV §◊Õ ∫“ߧ√—Èß®—ßÀ«–
¢Õß IMV ®–µ√ß°—∫™à«ßÀ“¬„®ÕÕ°¢ÕߺŸªâ «É ¬ ∑”„À⇰‘¥
°“√µâ“π‡§√◊ËÕ߉¥â
- Synchronized intermittent mandatory
ventilation (SIMV) ‡ªìπ«‘∏’ IMV ∑’‡Ë §√◊ÕË ß®–ª√—∫®—ßÀ«–
IMV „Àâµ√ß°—∫®—ßÀ«–∑’˺ŸâªÉ«¬‡√‘Ë¡À“¬„®‡Õß ‚Õ°“ ∑’Ë
®–‡°‘¥°“√µâ“π‡§√◊ËÕß°Á®–≈¥≈ß ´÷ËßÀ≈—°°“√∑”ß“π®–
70
Pediatric Respiratory and Critical Care
§≈⓬°—∫ AMV ·µà®”π«π§√—Èß∑’ˇ§√◊ËÕߙ૬À“¬„®®–§ß
∑’Ë µ “¡∑’Ë °”Àπ¥‰«â ‚¥¬ºŸâ ªÉ « ¬®–À“¬„®‡Õß„π™à « ß
√–À«à“ߧ√—ÈߢÕß°“√™à«¬À“¬„® ¢âÕ¥’¢Õß IMV/SIMV
‡¡◊ÕË ‡ª√’¬∫‡∑’¬∫°—∫ CMV §◊Õ ¡’°“√µâ“π‡§√◊ÕË ßπâÕ¬°«à“
∑”„Àâ°“√„™â¬“ sedation ·≈– muscle relaxant ≈¥≈ß,
§à“ MAP µË”°«à“∑”„À⡺’ ≈¥’µÕà CO, ≈¥°“√‡°‘¥ respiratory alkalosis, ·≈–™à«ß∑’ºË ªâŸ «É ¬À“¬„®‡Õß ∑”„Àâ gas
distribution ‰ª¬—ß dependent lung ¡“°¢÷Èπ ∑”„Àâ
°“√·≈°‡ª≈’ˬπ°ä“´¥’°«à“°“√™à«¬À“¬„®¥â«¬‡§√◊ËÕß
¢âÕ‡ ’¬§◊Õ ºŸâªÉ«¬Õ“®‰¡à‰¥â√—∫ ventilatory support ∑’Ë
‡æ’¬ßæÕ ·≈–Õ“®¡’°“√„™â·√ß„π°“√À“¬„®‡æ‘Ë¡¢÷Èπ∂â“
¢≥–∑’ºË ªŸâ «É ¬À“¬„®‡Õß¡’ flow rate ‰¡à‡æ’¬ßæÕ, demand
valve ¡’ sensitivity ŸßÀ√◊Õ respiratory circuit ¡’ resistance Ÿß
- Pressure support ventilation (PSV) À√◊Õ
∫“ߧπ‡√’¬°«à“ inspiratory assist ‡ªìπ«‘∏°’ “√™à«¬À“¬„®
∑’ˇ§√◊ËÕߙ૬À“¬„® “¡“√∂„Àâ flow rate ‡ √‘¡‡¢â“¡“
„π√–∫∫¢Õß∑àÕ∑“߇¥‘πÀ“¬„®„π¢≥–∑’ºË ªŸâ «É ¬À“¬„®‡Õß
‡æ◊ÕË ®–™à«¬≈¥ resistance ¢Õß circuit, demand valve
¢Õ߇§√◊ËÕß·≈– endotracheal tube ¢ÕߺŸâªÉ«¬ ¢≥–„™â
‡§√◊ÕË ß®–∑”ß“π —¡æ—π∏å°∫— ºŸªâ «É ¬‰¥â¥‡’ æ√“–ºŸªâ «É ¬®–‡ªìπ
ºŸâ°”Àπ¥Õ—µ√“°“√À“¬„® ·≈–‡«≈“∑’Ë„™â¢≥–À“¬„®‡¢â“
‚¥¬‡§√◊ËÕß®–°”Àπ¥®ÿ¥ ‘Èπ ÿ¥¥â«¬ flow (flow-cycled)
À√◊Õ‡«≈“ (∂â“ Ti ‡°‘π√âÕ¬≈– 80 ¢Õ߇«≈“√«¡∑’„Ë ™âÀ“¬„®
µàÕ§√—Èß) §à“ TV ∑’ˉ¥â°Á®–‡ª≈’ˬπ·ª≈߉ªµ“¡ pressure
∑’µË ßÈ— ‰«â·≈–§«“¡µâÕß°“√¢ÕߺŸªâ «É ¬‡Õß °“√„™â PSV ‰¡à
‡À¡“–°—∫ºŸâªÉ«¬∑’ˉ¡àÀ“¬„®‡ÕßÀ√◊Õ‰¡à¡’·√ßæÕ®–‡ªî¥
demand valve
™π‘¥¢Õ߇§√◊ËÕߙ૬À“¬„®·≈–«‘∏’ „™â
‡§√◊ËÕߙ૬À“¬„®„π‡¥Á°‚µ “¡“√∂·∫à߉¥â‡ªìπ 2
°≈ÿà¡„À≠àÊ §◊Õ volume ventilator ·≈– pressure ventilator
1. Volume ventilator §◊Õ ‡§√◊ËÕߙ૬À“¬„®∑’Ë
§«∫§ÿ¡ volume „Àâ§ß∑’·Ë µà pressure ∑’‡Ë °‘¥¢÷πÈ ®–‡ª≈’¬Ë π
·ª≈߉ªµ“¡ compliance ·≈– resistance ¢ÕߺŸâªÉ«¬
·≈–‡§√◊ÕË ß™à«¬À“¬„® °≈‰°°“√∑”ß“πÕ“®‡ªìπ volumecycled §◊Õ ®ÿ¥ ‘Èπ ÿ¥°“√À“¬„®‡¢â“∂Ÿ°°”Àπ¥ ‚¥¬
ª√‘¡“µ√∑’Ë„Àâ À√◊Õ‡ªìπ volume-controlled §◊Õ ‡§√◊ËÕß
®–«— ¥ ª√‘ ¡ “µ√∑’Ë ‡ °‘ ¥ ¢÷È π ·≈–„™â ª √‘ ¡ “µ√π—È π §«∫§ÿ ¡
volume À√◊Õ flow „Àâ§ß∑’Ë∑ÿ°Ê respiratory cycle
‡§√◊ËÕß∑’Ë¡’„™âÕ¬Ÿà ‡™àπ Puritan-Bennett ·≈– Siemens
servo
‡¡◊ËÕ‡√‘Ë¡„™â‡§√◊ËÕߺŸâ„™â®–µâÕß°”Àπ¥§à“ TV À√◊Õ
minute volume (TV X RR), Ti/pause time, RR,
high pressure limit alarm, low and high minute
volume alarm, PEEP, trigger sensitivity, FiO2 ∂â“
‡ªìπ‡§√◊ËÕß√ÿàπ„À¡àÊ ®–¡’ microprocessor ∑’Ë “¡“√∂
°”Àπ¥ flow waveform ·∫∫µà“ßÊ ‰¥â ‡™àπ square,
sinusoidal À√◊Õ accelerating or decelerating ramp
ª√–‚¬™πå∑’ˉ¥â®“° flow waveform „π≈—°…≥–µà“ßÊ
¬—߉¡à¡’À≈—°∞“π™—¥‡®π ·µàæ∫«à“‡¡◊ËÕ„™â decelerating
flow waveform ®–¡’§à“ MAP ∑’Ë Ÿß°«à“ ·≈–§à“ PIP ∑’Ë
µË”°«à“ square waveform ∑”„Àâ¡°’ “√·æ√à°√–®“¬¢Õß
°ä“´∑’¥Ë °’ «à“ ‚¥¬∑—«Ë ‰ª flow ∑’‡Ë §√◊ÕË ß„Àâ®–‡ªìπ demand
flow ·≈–¡’ flow waveform ·∫∫ square waveform
´÷Ëß —¡æ—π∏å°—∫§à“ TV ·≈– Ti (µ“√“ß∑’Ë 1)
2. Pressure ventilator §◊Õ ‡§√◊ËÕߙ૬À“¬„®
∑’˧«∫§ÿ¡ pressure „Àâ§ß∑’Ë à«π volume ∑’ˉ¥â®–
‡ª≈’¬Ë π·ª≈߉ªµ“¡ compliance ·≈– resistance ¢Õß
ºŸâªÉ«¬·≈–‡§√◊ËÕߙ૬À“¬„® °≈‰°°“√∑”ß“πÕ“®‡ªìπ
pressure-cycled §◊Õ ®ÿ¥ ‘πÈ ÿ¥°“√À“¬„®‡¢â“∂Ÿ°°”Àπ¥
‚¥¬ PIP ∑’˵—È߉«â flow „π‡§√◊ËÕß™π‘¥π’È®–‡ªìπ constant
flow ·≈–‡ªìπµ—«°”Àπ¥ Ti ‡¡◊ËÕ flow rate Ÿß Ti ®–
—Èπ‡æ√“– PIP ∂÷ß®ÿ¥∑’Ë°”À𥉫â‡√Á« ‡§√◊ËÕߙ૬À“¬„®
∑’Ë„™â°≈‰°π’È ‰¥â·°à Bird ventilator ´÷Ë߉¡àπ‘¬¡„™â„π‡¥Á°
Pressure ventilator „πªí®®ÿ∫π— ∑’πË ¬‘ ¡„™â‡ªìπ pressurecontrolled §◊Õ ‡§√◊ËÕß®–„Àâ flow waveform ‡ªìπ·∫∫
decelerating flow waveform ·≈– “¡“√∂§«∫§ÿ¡
Mechanical Ventilation in Pediatric Practice, π‘∑ ‡√◊Õß√Õß√—µπå 71
µ“√“ß∑’Ë 1 À≈—°°“√æ‘®“√≥“„Àâ initial setting ¢Õß volume ventilator
Parameters
TV
Ti, I:E ratio
Normal lung
10 mL/kg
µ“¡‡°≥±åÕ“¬ÿ
‚¥¬∑—Ë«‰ª„™â Ti 0.35-0.75
À√◊Õ I:E = 1:1.5, 1:2
RR
µ“¡‡°≥±åÕ“¬ÿ ‚¥¬∑—Ë«‰ª
Õ“¬ÿ 1 ªï 20-25/min
«—¬√ÿàπ 15-20/min
High pressure PIP ®–‡ª≈’ˬπ·ª≈ßµ“¡
limit alarm
flow rate, compliance
·≈– resistance
‚¥¬∑—Ë«‰ª®–µ—È߉«â Ÿß°«à“
PIP ¢ÕߺŸªâ «É ¬ 5-10 cmH2O
PEEP
Sensitivity
Decreased compliance
5-6 mL/kg
Õ“®µ—Èß Ti —Èπ°«à“ª°µ‘
·µà∂⓵âÕß°“√ MAP Ÿß
Õ“®µ—Èß„Àâ Ti π“π¢÷Èπ
·µàÕ“®∑”„À⺟âªÉ«¬Õ÷¥Õ—¥
À√◊Õ‡°‘¥ auto-PEEP
Õ—µ√“°“√À“¬„®®– Ÿß°«à“ª°µ‘
Increased resistance
5-10 mL/kg
µâÕߪ√—∫„À≥â Ti ∑’ˇÀ¡“– ¡·≈–
Te ∑’Ëπ“π¢÷Èπ‡æ◊ËÕÀ≈’°‡≈’ˬ߰“√
‡°‘¥ gas trapping ·≈– I:E =
1:3, 1:4
µ—È߉«â‰¡à„À⇰‘π 35 cmH2O
‡æ√“–«à“ pressure Ÿß
®–∑”„À⇰‘¥ volutrauma
·≈– barotrauma ∑’ˇ√’¬°«à“
ventilator induced lung injury
µ—È߉«â‰¡à„À⇰‘π 35 cmH2O
2-4 cmH2O
„πºŸâªÉ«¬∑’ˇªìπ ALI À√◊Õ ARDS
®–„™â optimum PEEP ¡—°‡√‘Ë¡∑’Ë
√–¥—∫ 7-10 cmH2O ·≈–¥Ÿ°“√
‡ª≈’ˬπ·ª≈ߢÕß SpO2 ‚¥¬
‡æ‘Ë¡§√—Èß≈– 1-2 cmH2O ∑ÿ°
10-15 π“∑’ ®π‰¥â§à“∑’ˇÀ¡“– ¡
Pressure trigger (-1)-(-2) cmH2O À√◊Õ Flow trigger 1-3 L/min
Õ—µ√“°“√À“¬„®§«√µË”°«à“ª°µ‘
2-4 cmH2O ‡æ◊ËÕÀ≈’°‡≈’Ë¬ß air
trapping ·≈– overinflation
‡æ‘Ë¡¢÷Èπ ´÷Ëß®–‡°‘¥ auto-PEEP
µ“¡¡“
µ“√“ß∑’Ë 2 À≈—°°“√æ‘®“√≥“°“√„Àâ initial setting ¢Õß pressure ventilator
Parameters
PIP
‡≈◊Õ° pressure ∑’ˇÀ¡“– ¡ ¥Ÿ‰¥â®“° chest movement ‡æ◊ËÕ„À≥â§à“ TV µ“¡µâÕß°“√ ·≈–‰¡à
„Àâ§à“ PIP Ÿß°«à“ 35 cmH2O ·≈–µâÕßµ—Èß high pressure limit ‰«â„Àâ Ÿß°«à“§à“ PIP ∑’Ë°”À𥉫â
5-10 cmH2O
Inspiratory rise time §◊Õ‡«≈“∑’Ë„™â„π°“√∑”„À⧫“¡¥—π Ÿß¢÷Èπ∂÷ß√–¥—∫ pressure ∑’˵—È߉«â ‚¥¬∑—Ë«‰ªª√–¡“≥ 100-500
msec ‡§√◊ËÕß∫“ß™π‘¥ª√—∫„Àâ‡√Á«„Àâ™â“‰¥â (0.1sec to 1 sec) „πºŸâªÉ«¬∑’ËÀ“¬„®ÀÕ∫≈÷°‡√Á« ¡’
flow demand Ÿß§«√µ—Èß„Àâ inspiratory rise time —Èπ ·µà∂⓺ŸâªÉ«¬À“¬„®™â“ inspiratory rise
time ∑’Ë —Èπ®–„Àâ flow ∑’Ëæÿà߇¢â“À“ºŸâªÉ«¬Õ¬à“ß·√ß ∑”„À⺟âªÉ«¬°≈—ÈπÀ“¬„®µâ“π‰¥â
PEEP
°“√‡æ‘Ë¡ PEEP ®–∑”„Àâ PIP Ÿßµ“¡¥â«¬‡æ√“–‡ªìπ§à“ pressure above PEEP ‡æ√“–∂â“ PIP
‰¡à‡æ‘Ë¡°Á®–∑”„Àâ§à“ pressure difference √–À«à“ß PIP ·≈– PEEP ≈¥≈ß ∑”„À≥â§à“ TV ≈¥≈ß
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Pediatric Respiratory and Critical Care
µ“√“ß∑’Ë 3 °“√‡ª√’¬∫‡∑’¬∫√–À«à“ß Pressure-controlled ·≈– Volume-controlled ventilation
Pressure-controlled ventilation
- §«∫§ÿ¡ pressure ‰¥â¥’ ·µà TV ∑’ˉ¥â®–‡ª≈’ˬπ·ª≈ßµ“¡ compliance ·≈– resistance ¢Õß√–∫∫ ·≈–°“√
ª√—∫≈¥ minute ventilation ∑”‰¥â¬“°°«à“
- ≈¥°“√‡°‘¥ barotrauma ·≈– volutrauma
- º≈¢Õß decelerating flow ∑”„Àâ oxygenation ¥’¢÷Èπ ≈¥ dead space ventilation ®“° MAP ∑’Ë Ÿß¢÷Èπ
Volume-controlled ventilation
- „Àâ volume (TV) ∑’§Ë ß∑’Ë ™à«¬≈¥°“√‡°‘¥ hypoventilation À√◊Õ hyperventilation ·µà pressure ®–‡ª≈’¬Ë π·ª≈ßµ“¡
compliance ·≈– resistance ¢Õß√–∫∫
- °“√µ—Èß pressure alarm ∑’ˇÀ¡“– ¡®–™à«¬‡µ◊Õπ∂÷ß°“√‡ª≈’ˬπ·ª≈ß respiratory mechanic ∑’ˇ°‘¥¢÷Èπ°√–∑—πÀ—π
‡™àπ pneumothorax, airway obstruction ‡ªìπµâπ
- ∂⓵—Èß pressure alarm ‰¡à‡À¡“– ¡ PIP ∑’ˇª≈’ˬπ·ª≈ß Ÿß¢÷Èπ„πºŸâªÉ«¬®–∑”„À⇰‘¥ barotrauma ‰¥â
- ¡’‚Õ°“ ‡°‘¥ patient-ventilator dyssynchrony „πºŸâªÉ«¬∑’Ë¡’ peak inspiratory flow ¡“°°«à“ constant flow ∑’Ë
‡§√◊ËÕß®à“¬„Àâ
pressure „Àâ§ß∑’µË ≈Õ¥™à«ß°“√À“¬„®‡¢â“ ‡§√◊ÕË ß∑’¡Ë „’ ™âÕ¬Ÿà
‡™àπ Puritan-Bennett ·≈– Siemens servo
‡¡◊ËÕ‡√‘Ë¡„™â‡§√◊ËÕߺŸâ„™â®–µâÕß°”Àπ¥§à“ PIP, Ti/
pause time, inspiratory rise time, RR, high pressure limit alarm, low and high minute volume alarm,
PEEP, trigger sensitivity, FiO2 (µ“√“ß∑’Ë 2 ·≈– 3)
‡§√◊ÕË ß™à«¬À“¬„®√ÿπà „À¡àÊ ¡—°®– “¡“√∂‡≈◊Õ°„™â
«‘∏’°“√™à«¬À“¬„®∑—Èß volume controlled ·≈– pressure controlled ‰¥â„π‡§√◊ËÕ߇¥’¬«°—π „π∫“߇§√◊ËÕ߬—ß
“¡“√∂µ—Èß«‘∏’°“√™à«¬À“¬„®∑’˧«∫§ÿ¡∑—Èß volume ·≈–
pressure ‰¥â„π¢≥–‡¥’¬«°—π ‰¥â·°à °“√„™â PRVC mode
Pressure regulated volume control (PRVC)
‡ªìπ mode ∑’¡Ë Õ’ ¬Ÿ„à π‡§√◊ÕË ß Servo ventilator 300/300A
‚¥¬π”¢âÕ¥’¢Õß volume-controlled ·≈– pressurecontrolled ventilation ¡“√«¡°—π ºŸâ„™â®–µâÕß°”Àπ¥
§à“ TV/minute volume, RR, Ti, high pressure limit
alarm, low and high minute volume alarm, PEEP,
trigger sensitivity, FiO2 ‡À¡◊Õπ volume ventilator
·µà‡§√◊ËÕß®–∑”ß“π‚¥¬„™â decelerating flow ∑”„À≥â
pressure waveform ‡ªìπ·∫∫ square wave °“√À“¬„®
§√—Èß·√°®–‡ªìπ test breath ´÷Ë߇§√◊ËÕß®–„Àâ·√ߥ—π 10
cmH2O above PEEP ‡¢â“¡“„π√–∫∫ µàÕ®“°π—πÈ ‡§√◊ÕË ß
®–§”π«≥ compliance ¢Õß√–∫∫∑ÿ° 4 breaths ·≈â«
ª√—∫‡æ‘Ë¡ pressure ‚¥¬°“√‡æ‘Ë¡ pressure ¢÷Èπ§√—Èß≈–
3 cmH2O/breath ‡æ◊ËÕ„À≥â preset volume ·≈–√–¥—∫
pressure Ÿß ÿ¥∑’ˇ§√◊ËÕß®–ª√—∫‡æ‘Ë¡„À≥â´÷Ëß®–µË”°«à“
high pressure limit Õ¬à“ßπâÕ¬ 5 cmH2O ‡ ¡Õ ∂â“
volume ‡°‘π∑’˵—È߉«â‡§√◊ËÕß°Á®–ª√—∫≈¥ pressure ≈ß
§√—Èß≈– 3 cmH2O/breath ‡™àπ°—π
”À√— ∫ °“√ª√— ∫ µ—È ß °“√„™â «‘ ∏’ ™à « ¬À“¬„®·∫∫
SIMV ·≈– PSV mode ¡’«‘∏’°“√¥—ß √ÿª‰«â„πµ“√“ß∑’Ë
4 ·≈– 5
‘Ëß∑’˵âÕßæ‘®“√≥“‡æ‘Ë¡‡µ‘¡¢≥–„™â‡§√◊ËÕߙ૬
À“¬„® ‰¥â·°à
- °“√„À⧫“¡™◊Èπ (humidification) ¡’§«“¡
”§—≠¡“°„πºŸâªÉ«¬∑’Ë„™â‡§√◊ËÕߙ૬À“¬„® ‡π◊ËÕß®“°
°ä“´∑’Ë„™â®–·Àâß·≈–§«“¡‡¢â¡¢âπ¢ÕßÕÕ°´‘‡®π∑’Ë Ÿß®–
∑”≈“¬‡¬◊ËÕ∫ÿ∑“߇¥‘πÀ“¬„® ‡§√◊ËÕߙ૬À“¬„®∑’Ë„™â°—π
Mechanical Ventilation in Pediatric Practice, π‘∑ ‡√◊Õß√Õß√—µπå 73
µ“√“ß∑’Ë 4 °“√ª√—∫µ—Èß°“√„™â«‘∏’™à«¬À“¬„®·∫∫ SIMV mode
Mode
SIMV
Trigger
Limit
Cycle
Important considerations
pressure or flow volume or pressure volume or flow or time
¥—ß√“¬≈–‡Õ’¬¥¢â“ß≈à“ß
1. SIMV cycle §◊Õ ™à«ß‡«≈“∑’ˉ¥â®“°°“√§”π«≥‚¥¬„™â§à“ 60/preset SIMV rate ·µà≈– SIMV cycle ®–
ª√–°Õ∫¥â«¬ 2 à«π ‰¥â·°à SIMV period ·≈– spontaneous period
2. SIMV period (SIMV window) §◊Õ ™à«ß°“√À“¬„®∑’Ë∂Ÿ°™à«¬‚¥¬‡§√◊ËÕߙ૬À“¬„® (mandatory breath)
´÷Ë߇§√◊ËÕß®–™à«¬À“¬„®¥â«¬ TV ·≈– SIMV rate µ“¡∑’˺Ÿâ„™âµ—È߉«â ‚¥¬∑’Ë§à“ SIMV period ®–∂Ÿ°°”Àπ¥
¥â«¬ CMV rate setting ‡™àπ ºŸâ„™âµ—ÈßCMV rate = 30/min ‡«≈“∑’Ë„™âµàÕ§√—ÈߢÕß SIMV period ®–‡∑à“°—∫
(60/30)= 2 sec À¡“¬§«“¡«à“„π‡«≈“ 2 «‘π“∑’‡§√◊ËÕß®–„Àâ mandatory breath 1 §√—Èß´÷Ëßµ√ß°—∫®—ßÀ«–
∑’˺ŸâªÉ«¬‡√‘Ë¡À“¬„® (synchronized) ·≈–∂⓵—Èß Ti = 0.5 sec, Te = 1.5 (I:E = 1:3) ∂Ⓡ«≈“ºà“π‰ª§√∫ 2
«‘π“∑’ ºŸâªÉ«¬¬—߉¡àÀ“¬„®‡Õ߇§√◊ËÕß°Á®–„Àâ mandatory breath ™à«¬ºŸâªÉ«¬µ“¡∑’Ë°”À𥉫â
3. Spontaneous period §◊Õ ™à«ß°“√À“¬„®∑’˺ŸâªÉ«¬ “¡“√∂À“¬„®‰¥â‡Õß ‡ªìπ‡«≈“∑’ˉ¥â®“° SIMV cycle SIMV period ‡™àπ ºŸâ„™â°”Àπ¥„Àâ SIMV rate = 10/min ¥—ßπ—Èπ‡«≈“¢Õß SIMV cycle µàÕ§√—Èß®–‡∑à“°—∫
(60/10)= 6 sec ·≈–∂â“ SIMV period = 2 sec §à“ spontaneous period ®–‡∑à“°—∫ (6-2)= 4 sec ‚¥¬
‡§√◊ËÕß®–„Àâ continuous flow À√◊Õ demand flow ‡¢â“¡“„π√–∫∫¢≥–∑’˺ŸâªÉ«¬À“¬„®‡Õß ·≈–∂â“„™â SIMV
+ PS ™à«ßπ’È®–¡’ inspiratory pressure support À√◊Õ SIMV + VS ®–¡’ volume support ¡“™à«¬ºŸâªÉ«¬
¢≥–À“¬„®‡Õß
4. SIMV ∑’Ë¡’„™â„π‡§√◊ËÕߙ૬À“¬„® à«π„À≠à®–‡ªìπ volume preset ·µà¡’‡§√◊ËÕß∫“ß√ÿà𠇙àπ Servo 300 ®–
¡’∑—Èß·∫∫ volume preset ·≈–·∫∫ pressure preset „π·∫∫ pressure preset ‡™◊ËÕ«à“®–¡’ª√–‚¬™πå„π
ºŸâªÉ«¬∑’Ë¡’ªí≠À“ leakage ∑’Ë endotracheal tube À√◊ÕºŸâªÉ«¬∑’˵âÕß°“√ high initial flow rate
5. ∂Ⓡ°‘¥ irregular breathing ¡—°¡’ “‡Àµÿ®“°™à«ß mandatory breath ·≈– spontaneous breath ‰¡à
—¡æ—π∏å°—π
µ“√“ß∑’Ë 5 °“√ª√—∫µ—Èß°“√„™â«‘∏’™à«¬À“¬„®·∫∫ PSV mode
Mode
PSV
Trigger
Limit
Cycle
Important considerations
pressure or flow
pressure
flow
¥—ß√“¬≈–‡Õ’¬¥¢â“ß≈à“ß
1. µâÕßµ—Èß low minute volume „Àâ‡À¡“– ¡
2. µâÕߧլ‡ΩÑ“µ‘¥µ“¡§à“ TV Õ¬à“ß„°≈♑¥ ‡æ√“–®–‡ª≈’ˬπ·ª≈ßµ“¡°“√‡ª≈’ˬπ·ª≈ߢÕß respiratory
mechanic Õ¬Ÿàµ≈Õ¥
3. °“√µ—Èß§à“ pressure support (PS) ∑’ˇÀ¡“– ¡®–µâÕ߇ªìπ§à“∑’˵˔ ÿ¥∑’˺ŸâªÉ«¬ “¡“√∂√—°…“ physiologic
RR ·≈– TV ‰«â‰¥â ¡—°®–µ—È߉«â∑’Ë 15-20 cmH2O À√◊Õª√–¡“≥§à“ (PIP + PEEP)
2
4. °“√„™â PSV ºŸâªÉ«¬®–√Ÿâ ÷° ∫“¬°«à“°“√„™â conventional mechanical ventilation (CMV) ‡π◊ËÕß®“°
ºŸâªÉ«¬ “¡“√∂§«∫§ÿ¡§«“¡≈÷° §«“¡¬“« ·≈–≈—°…≥– flow pattern ‰¥â„π·µà≈–§√—Èß∑’ËÀ“¬„®
5. PSV “¡“√∂≈¥ WOB ∑’ˇ°‘¥®“° endotracheal tube ‰¥â §à“ PS ∑’Ë„™â·µ°µà“ß°—πµ—Èß·µà 6-10 cmH2O
¢÷Èπ°—∫¢π“¥ tube (ETT size 3-3.5 = 10 cmH2O; 4-4.5 = 8 cmH2O; > 5 = 6 cmH2O)
74
Pediatric Respiratory and Critical Care
∑—Ë«‰ª®–¡’ heated humidifier Õ¬Ÿà¥â«¬ ‡æ◊ËÕ„À⧫“¡™◊Èπ
·°àÕ“°“»∑’Ë„Àâ°—∫ºŸâªÉ«¬ ‚¥¬∑—Ë«‰ª®–ª√—∫„ÀâÕÿ≥À¿Ÿ¡‘
¢Õß°ä“´∑’Ë„™âÀ“¬„®‡¢â“ª√–¡“≥ 33 + 2oC ·≈–µâÕß¡’
°“√‡ΩÑ“√–«—߉¡à„ÀâÕÿ≥À¿Ÿ¡‘¢Õß°ä“´ ŸßÀ√◊յ˔‡°‘π‰ª
∂Ⓡ§√◊ËÕß humidifier ‰¡à¡’∑’Ë«—¥Õÿ≥À¿Ÿ¡‘„Àℙ⫑∏’ —߇°µ
«à“§à“Õÿ≥À¿Ÿ¡‘¢Õß°ä“´∑’Ë„™â‰¥â®–∑”„À⇰‘¥‰ÕπÈ”‡°“–∑’Ë
∑àÕπ”°ä“´‡¢â“
- °“√¡’√–∫∫‡ΩÑ“µ‘¥µ“¡∑’¥Ë ’ (monitoring) ‡¡◊ÕË
ª√—∫µ—ßÈ ‡§√◊ÕË ß™à«¬À“¬„®·≈–µàÕ‡§√◊ÕË ß°—∫ºŸªâ «É ¬®–µâÕß¡’
√–∫∫‡ΩÑ“µ‘¥µ“¡∑’¥Ë ’ ´÷ßË µâÕß„™â∑¡’ ·æ∑¬å·≈–欓∫“≈∑’¡Ë ’
§«“¡√Ÿ§â «“¡ “¡“√∂ ·≈–‡§√◊ÕË ß¡◊Õ∑’¡Ë ª’ √– ‘∑∏‘¿“æ ‡æ◊ÕË
™à«¬„Àâ∑¡’ ¡’‡«≈“∑’®Ë –·°â‰¢¿“«–º‘¥ª°µ‘µ“à ßÊ ¢ÕߺŸªâ «É ¬
„À⥢’ π÷È ·≈–√–«—߉¡à„À⇰‘¥¿“«–·∑√°´âÕπ∑’‡Ë °‘¥®“°°“√
„™â‡§√◊ËÕߙ૬À“¬„® À≈—°°“√ ”§—≠¡’¥—ßπ’È °“√µ√«®
√à“ß°“¬Õ¬à“ß≈–‡Õ’¬¥ ‚¥¬‡©æ“– vital signs (temperature, RR, PR, BP), °“√„™â bedside monitoring (continuous ECG, pulse oximetry ·≈–/À√◊Õ CVP, end
tidal CO2 ), °“√ àßµ√«® arterial blood gas (ABG)/
capillary blood gas (CBG)·≈– chest X-ray ‡¡◊ËÕ¡’
¢âÕ∫àß™’,È °“√¥Ÿ¥‡ ¡À– ·≈–°“√µ√«® Õ∫§«“¡ —¡æ—π∏å
¢ÕߺŸâªÉ«¬·≈–‡§√◊ËÕߙ૬À“¬„®
sepsis, burns, trauma, hyperthyroidism, ·≈–§«“¡
‡®Á∫ª«¥√ÿπ·√ß ‡ªìπµâπ
2. °“√µ—ßÈ ‡§√◊ÕË ß™à«¬À“¬„®∑’‰Ë ¡à‡À¡“– ¡ ‰¥â·°à
- °“√µ—Èß trigger threshold „Àâ¡’ sensitivity
‰¡à‡À¡“– ¡
- °“√µ—ßÈ peak flow rate delivery ∑’µË Ë”‡°‘π‰ª
- °“√µ—Èß inspiratory time ∑’ˬ“«‡°‘π‰ª „π
°“√„™â A/C mode
- °“√µ—Èß inspiratory pressure ∑’˵˔‡°‘π‰ª
„π°“√„™â PSV mode
- °“√µ—Èß RR ∑’˵˔‡°‘π‰ª „π°“√„™â SIMV
mode
- °“√µ—Èß RR ∑’Ë Ÿß‡°‘π‰ª ‚¥¬‡©æ“–ºŸâªÉ«¬
∑’Ë¡’ªí≠À“ airway obstruction ∑”„À⇰‘¥ dynamic
hyperinflation ·≈– auto-PEEP
°“√·°âªí≠À“∑’˵√ß°—∫ “‡Àµÿ®–∑”„Àâ°“√À“¬„®
¢ÕߺŸªâ «É ¬ —¡æ—π∏å°∫— ‡§√◊ÕË ß™à«¬À“¬„®¥’¢π÷È ·µàºªŸâ «É ¬∫“ß
√“¬∑’æË ¬“∏‘ ¿“æ¡’§«“¡º‘¥ª°µ‘√πÿ ·√ß°Á¡§’ «“¡®”‡ªìπ
®–µâÕß„™â¬“°≈ÿ¡à sedatives ·≈–/À√◊Õ muscle relaxant
‰ª°àÕπ„π√–¬–·√°‡æ◊ÕË ®–‰¥â„Àâ°“√™à«¬‡À≈◊ÕºŸªâ «É ¬¥â«¬
‡§√◊ËÕߙ૬À“¬„®‰¥âÕ¬à“ß¡’ª√– ‘∑∏‘¿“æ
°“√µ√«® Õ∫§«“¡ —¡æ—π∏å¢ÕߺŸªâ «É ¬·≈–‡§√◊ÕË ß™à«¬
À“¬„® (Ventilator-patient interaction)1,5
°“√‡°‘¥ªí≠À“ºŸâªÉ«¬µâ“π‡§√◊ËÕߙ૬À“¬„®À√◊Õ
À¬ÿ¥À“¬„® ¡’ªí®®—¬∑’˵âÕßæ‘®“√≥“¥—ßπ’È
1. Respiratory drive “‡Àµÿ¡’∑—Èß∑’Ë≈¥≈ß·≈–
‡æ‘Ë¡¢÷Èπ
“‡Àµÿ∑’Ë≈¥≈ß∑”„ÀâÀ¬ÿ¥À“¬„®À√◊ÕÀ“¬„®‰¡à
·√ßæÕ ‰¥â·°à °“√„™â¬“°≈ÿà¡ sedatives ·≈– narcotics, ¡’¿“«– metabolic alkalosis, ¡’¿“«– malnutrition ∑’√Ë πÿ ·√ß, ·≈– ¡’ severe brainstem injury ‡ªìπµâπ
“‡Àµÿ∑’ˇæ‘Ë¡¢÷Èπ∑”„ÀâÀ“¬„®µâ“π‡§√◊ËÕߙ૬
À“¬„® ‰¥â·°à ¿“«– hypoxia, hypercarbia, metabolic
acidosis, ‰¢â Ÿß, ¿“«– hypermetabolic states ‡™àπ
¬“∑’Ë „™â¢≥–„™â‡§√◊ËÕߙ૬À“¬„®3
¥—ßµ“√“ß∑’Ë 6
°“√À¬ÿ¥„™â‡§√◊ËÕߙ૬À“¬„® (Weaning from
mechanical ventilation)1,6
Weaning À¡“¬∂÷ß «‘∏’§àÕ¬Ê ≈¥√–¥—∫¢Õß°“√
„™â‡§√◊ËÕߙ૬À“¬„®„πºŸâªÉ«¬ ‡æ◊ËÕ„Àâ “¡“√∂À¬ÿ¥„™â
‡§√◊ËÕߙ૬À“¬„®‰¥âÕ¬à“ߪ≈Õ¥¿—¬
°“√æ‘®“√≥“ wean ºŸªâ «É ¬®“°‡§√◊ÕË ß™à«¬À“¬„®
¡’À≈—°°“√¥—ßπ’È
1. ‚√§À√◊Õ欓∏‘ ¿“楗È߇¥‘¡¢ÕߺŸâªÉ«¬∑’Ë∑”„Àâ
µâÕß„™â‡§√◊ËÕߙ૬À“¬„®®–µâÕߥ’¢÷Èπ°àÕπ (reversal of
indication for ventilation)
Mechanical Ventilation in Pediatric Practice, π‘∑ ‡√◊Õß√Õß√—µπå 75
µ“√“ß∑’Ë 6 ¬“∑’Ë„™â¢≥–„™â‡§√◊ËÕߙ૬À“¬„®3
Drug
Midazolam
Intravenous dose
(mg/kg)
0.05-0.15
Lorazepam
Diazepam
Morphine
0.05-0.1
0.1-0.2
0.1-0.2
Fentanyl
Pancuronium
Vecuronium
Atracurium
1-2 mcg/kg
0.05-0.1
0.1
0.5
Infusion dose
Loading: 0.05 mg/kg
Maintenance: 0.5-1 mcg/kg/min
Loading: 0.05 mg/kg
Maintenance: 0.02 mg/kg/hour
Continuous 1 mcg/kg/hour
Continuous 0.1 mg/kg/hour
Continuous 0.1 mg/kg/hour
Continuous 0.3-0.6 mg/kg/hour
2. ºŸâªÉ«¬§«√®–¡’°“√·≈°‡ª≈’ˬπ°ä“´∑’ˇ撬ßæÕ
(adequate gas exchange)
- PaO2 > 60 mmHg, FiO2 < 0.35 and
PEEP < 5 cmH2O
- P(A-a)O2 < 350 mmHg, FiO2 > 1.0
- PaO2 / FiO2 > 200
- Shunt fraction (Qs/Qt) < 15%, FiO2 >
1.0
- TV > 5 mL/kg
- Force vital capacity (FVC) > 15 mL/kg
- Minute ventilation (MV) < 10 L/min,
maximal voluntary ventilation > 2 MV
- Negative inspiratory pressure < -30
cmH2O
- Ratio of dead space to tidal volume
(Vd/Vt) < 0.55
3. ºŸâªÉ«¬®–µâÕß¡’°“√∑”ß“π¢Õß√–∫∫Õ«—¬«–
µà“ßÊ ‰¥âÕ¬à“߇À¡“– ¡ ‰¥â·°à intact respiratory drive,
cardiovascular stability, optimal hemoglobin, normal or near normal electrolytes, normal body temperature, adequate nutrition status, absence of
other major organ system failure
Duration of
action
1-2 hour
3-6 hour
0.5-3 hour
4 hour
30-60 min
50-60 min
30-90 min
5-15 min
«‘∏’°“√ weaning
„π‡¥Á°‡≈Á°¡—°„™â«‘∏’ IMV ¥â«¬°“√‡√‘Ë¡≈¥ ‘Ëß∑’ˇªìπ
Õ—πµ√“¬µàÕªÕ¥¡“°∑’Ë ÿ¥°àÕπ §◊Õ FiO2 ·≈– PIP ∂â“
§à“¢Õß FiO2 ·≈– PIP Õ¬Ÿà„π√–¥—∫∑’˵˔æÕ·≈â«°Á®–≈¥
Õ—µ√“°“√À“¬„®¢Õ߇§√◊ËÕߙ૬À“¬„®≈߉ª‡√◊ËÕ¬Ê ∂â“
ventilator setting ‡ªìπ FiO2 < 0.4, PIP < 15 cmH2O
·≈– RR 5-10/min °Á®–æ‘®“√≥“À¬ÿ¥°“√„™â‡§√◊ËÕߙ૬
À“¬„® „π‡¥Á°‡≈Á°‰¡à·π–π”„Àâ wean ¥â«¬ CPAP Õ¬à“ß
‡¥’¬«‡æ√“–ºŸªâ «É ¬¡’∑Õà ™à«¬À“¬„®¢π“¥‡≈Á°´÷ßË ¡’ airway
resistance Ÿß ∑”„ÀâµâÕßÕÕ°·√ß¡“°„π°“√À“¬„®‡Õß
„π‡¥Á°‚µ°“√ wean ¡’«‘∏’°“√µà“ßÊ ¥—ßπ’È
1. Abrupt discontinuation §◊Õ À¬ÿ¥„™â∑—π∑’
‡À¡“– ”À√—∫ºŸªâ «É ¬∑’„Ë ™â‡§√◊ÕË ß™à«¬À“¬„®√–¬– —πÈ ‰¡à‡°‘π
2-3 «—𠇙àπ ºŸâªÉ«¬À≈—ßºà“µ—¥
2. PSV mode ¢âÕ¥’¢Õß°“√„™â pressure support §◊Õ “¡“√∂≈¥‡«≈“°“√µÕ∫ πÕß (response
time) ¢Õß°“√„™â demand valve ‡¡◊ËÕ‡∑’¬∫°—∫ SIMV
mode ·≈–¬—߇æ‘Ë¡°“√™à«¬°“√∑”ß“π¢Õß°≈â“¡‡π◊ÈÕ
À“¬„® ·≈–≈¥ WOB ¢Õß°≈â“¡‡π◊ÈÕÀ“¬„® ‡¡◊ËÕ‡√‘Ë¡„™â
ºŸâªÉ«¬§«√®– “¡“√∂√—°…“ physiologic RR ·≈– TV
‰«â‰¥â ·≈–√Ÿ â °÷ ∫“¬ µàÕ®“°π—πÈ §àÕ¬Ê ≈¥√–¥—∫¢Õß pressure support §√—Èß≈– 2-3 cmH2O ®π‡À≈◊Õ§à“ pres-
76
Pediatric Respiratory and Critical Care
sure support æÕ ”À√—∫≈¥ WOB ∑’‡Ë °‘¥®“° endotracheal tube ‰¥â°Á®–À¬ÿ¥°“√„™â‡§√◊ËÕߙ૬À“¬„®
3. SIMV mode ®–§≈⓬§≈÷ß°—∫°“√ wean ¥â«¬
PSV mode ‚¥¬∑’Ë SIMV ®–¡’ª√–‚¬™πå¡“°∑’ Ë ¥ÿ „π°√≥’
∑’˵âÕß°“√ wean Õ¬à“ß√«¥‡√Á« à«π„À≠à‡¡◊ËÕ≈¥ SIMV
rate ‡À≈◊ÕπâÕ¬°«à“À√◊Õ‡∑à“°—∫ 4 §√—ÈßµàÕπ“∑’ ‚¥¬‰¡à¡’
Õ“°“√ÀÕ∫‡Àπ◊ËÕ¬‡ªìπ‡«≈“ 1-2 ™—Ë«‚¡ß °Á®–À¬ÿ¥°“√
„™â‡§√◊ËÕߙ૬À“¬„®
4. SIMV combine with PSV mode ªí®®ÿ∫—π¡’
ºŸâ„™â«‘∏’π’È¡“°¢÷Èπ
5. T-piece/CPAP/spontaneous breathing trail
‡ªìπ«‘∏°’ “√¥—ßÈ ‡¥‘¡ °“√∑¥≈Õß wean Õ“®®–‡√‘¡Ë „™â‡«≈“
5 π“∑’«π— ≈–§√—ßÈ ®π°√–∑—ßË «—π≈–À≈“¬Ê §√—ßÈ ·µà‰¡à§«√
∑”‡°‘π°«à“ 2-3 §√—ßÈ µàÕ«—π·≈–·µà≈–§√—ßÈ ‰¡à§«√π“π‡°‘π
60 π“∑’ ‘Ëß ”§—≠∑’Ë≈◊¡‰¡à‰¥â §◊Õ ºŸâªÉ«¬®–µâÕ߉¥â√—∫°“√
æ—°ºàÕπÕ¬à“߇µÁ¡∑’Ë„π™à«ß°≈“ߧ◊π ∂⓺ŸâªÉ«¬ºà“π°“√
∑¥≈Õß wean π“π 30-60 π“∑’ ‚¥¬‰¡à¡’Õ“°“√¢Õß
°≈â“¡‡π◊ÈÕÀ“¬„®ÕàÕπ·√ß °Á®–À¬ÿ¥°“√„™â‡§√◊ËÕߙ૬
À“¬„®
°“√‡Õ“∑àՙ૬À“¬„®ÕÕ°®“°ºŸâªÉ«¬ (extubation)
¡’À≈—°°“√æ‘®“√≥“‚¥¬„™â CALM criteria ‰¥â·°à
C = Central nervous system: √Ÿâ ÷°µ—«¥’
æÕ§«√ À“¬„®‰¥â‡Õß
A = Airway: ∑“߇¥‘πÀ“¬„®‡ªî¥‚≈àß ‰¡àµ’∫À√◊Õ
∫«¡∫√‘‡«≥ subglottic mucosa ´÷Ëß∑¥ Õ∫‚¥¬°“√∑”
leak test ª°µ‘®–¡’ leak ∑’Ë·√ߥ—πª√–¡“≥ 20 cmH2O
ºŸâªÉ«¬¡’‡ ¡À–‰¡à¡“° ’ª°µ‘·≈–‰¡à‡À𒬫 ¡’ gag
reflex ·≈– cough reflex ª°µ‘
L = Lung: ‡π◊ÈÕªÕ¥®–µâÕߧàÕπ¢â“ߪ°µ‘ ¡’°“√
·≈°‡ª≈’ˬπ°ä“´∑’ˇ撬ßæÕ ´÷Ëߪ√–‡¡‘π‰¥â®“°°“√µ√«®
√à“ß°“¬ °“√‡ª≈’ˬπ·ª≈ß∑’ˇÀÁπ®“°¿“æ√—ß ’∑√«ßÕ°
°“√µ√«® ABG
M = Muscle: °≈â“¡‡π◊ÕÈ ∑’‡Ë °’¬Ë «¢âÕß°—∫°“√À“¬„®
®–µâÕß·¢Áß·√ßæÕ °“√∑”ß“π¢Õß°–∫—ß≈¡®–µâÕßÕ¬Ÿ„à π
¿“檰µ‘ ´÷ßË ∑¥ Õ∫‚¥¬°“√∑” negative inspiratory
pressure
°“√¥Ÿ·≈ºŸâªÉ«¬À≈—߇Փ∑àՙ૬À“¬„®ÕÕ°®–µâÕß
„À⺟âªÉ«¬Õ¬Ÿà —߇°µÕ“°“√Õ¬à“ß„°≈♑¥„πÀÕºŸâªÉ«¬Àπ—°
Õ¬à“ßπâÕ¬ 24 ™—Ë«‚¡ß ¢≥–Õ¬Ÿà„πÀÕºŸâªÉ«¬Àπ—°®–µâÕß
ªØ‘∫—µ‘¥—ßπ’È
- Monitoring vital signs ·≈– àßµ√«® ABG/
CBG, chest X-ray Õ¬à“ßπâÕ¬ 1 §√—Èß
- „Àâ°“√∫”∫—¥¥â«¬ÕÕ°´‘‡®π ‚¥¬°“√„™âÕªÿ °√≥å
∑’ˇÀ¡“– ¡°—∫ºŸâªÉ«¬ ‡™àπ oxygen cannula, oxygen
hood À√◊Õ oxygen mask ·≈–„À⧫“¡™◊Èπ∑’ˇ撬ßæÕ
- NPO ª√–¡“≥ 6 ™—Ë«‚¡ß·≈–„Àâ “√πÈ”∑“ß
À≈Õ¥‡≈◊Õ¥‰ª°àÕπ ‡æ◊ËÕªÑÕß°—π°“√ Ÿ¥ ”≈—° ‡π◊ËÕß®“°
„π√–¬–·√°∫√‘‡«≥ glottis ¬—߉¡à “¡“√∂°≈—∫¡“∑”ß“π
‰¥â‡µÁ¡∑’Ë
- πÕπ»’√…– Ÿßª√–¡“≥ 30 Õß»“ §Õ‰¡àæ—∫
‡æ◊ËÕ„Àâ∑“߇¥‘πÀ“¬„®‡ªî¥‚≈àß
- 欓¬“¡√∫°«πºŸâªÉ«¬„ÀâπâÕ¬∑’Ë ÿ¥ ¥Ÿ¥‡ ¡À–
‡∑à“∑’®Ë ”‡ªìπ ∂⓺Ÿªâ «É ¬¡’Õ“°“√À“¬„®≈”∫“° ·≈–À“¬„®
¡’‡ ’¬ß stridor Õ“®≈Õß„Àâ°“√√—°…“¥â«¬ aerosolized
epinephrine 1:1,000 ¢π“¥ 0.5 mL/kg (max. 5 mL)
·≈–ª√–‡¡‘πº≈°“√√—°…“ ∂⓵âÕß„™â¬“‡°‘π 2 §√—Èߧ«√
æ‘®“√≥“„ à∑àՙ૬À“¬„®‰ª°àÕπ (reintubation)
¿“«–·∑√°´âÕπ∑’ˇ°‘¥®“°°“√„™â‡§√◊ËÕߙ૬À“¬„®1,4,5
1. ¿“«–·∑√°´âÕπµàÕªÕ¥ (pulmonary complication)
Õ—πµ√“¬∑’ˇ°‘¥¢÷ÈπµàÕ‡π◊ÈÕªÕ¥‡ªìπº≈¡“®“°
À≈“¬ªí®®—¬ ‰¥â·°à 欓∏‘ ¿“楗ßÈ ‡¥‘¡ barotrauma (®“°
alveolar overdistention ‡™◊ËÕ«à“ —¡æ—π∏å°—∫°“√„™â high
PEEP), volutrauma (®“° TV ∑’Ë¡“°‡°‘π´÷Ëß —¡æ—π∏å
°—∫ high PIP ·≈– plateau pressure), atelectrauma
(®“° shear stress ¢Õß°“√‡ªî¥ªî¥´È”Ê ¢Õß alveoli )
·≈– oxygen toxicity ( —¡æ—π∏å°—∫ FiO2 > 0.5) ∑”„Àâ
‡°‘¥ ventilator induced lung injury (VILI) ·≈–/À√◊Õ
Mechanical Ventilation in Pediatric Practice, π‘∑ ‡√◊Õß√Õß√—µπå 77
pulmonary air leak ‡™àπ pneumothorax, pneumomediastinum, PIE, subcutaneous emphysema À√◊Õ
brochopleural fistula ‡ªìπµâπ „π‡¥Á°∑“√°∑”„À⇰‘¥
bronchopulmonary dysplasia, retinopathy of prematurity 䴉
2. ¿“«–·∑√°´âÕπµàÕ√–∫∫‰À≈‡«’¬π‚≈À‘µ
(cardiovascular complication)
§à“ MAP ®“°‡§√◊ËÕߙ૬À“¬„®∑”„Àâ·√ߥ—π
„π™àÕß∑√«ßÕ°‡ªìπ∫«° ®–¡’º≈°√–∑∫µàÕ√–∫∫°“√‰À≈
‡«’¬π‚≈À‘µ¥—ßπ’È
- impede venous return and decreased
right ventricular filling (right ventricular stroke volume)
- increased afterload on the right ventricle
- cause the interventricular septum to
shift toward the left ventricle
- decreased volume of the left ventricle
(reduction left ventricular stroke volume) cause
decreased cardiac output
- may cause afterload reduction on the
left ventricle
3. ¿“«–·∑√°´âÕπµàÕ∑“߇¥‘πÀ“¬„® (airway
complication)
¢≥–„™â‡§√◊ËÕߙ૬À“¬„® Õ“®‡°‘¥ªí≠À“∑àÕ
™à«¬À“¬„®À≈ÿ¥‚¥¬‰¡àµ—Èß„® (accidental extubation),
ªí≠À“∑àՙ૬À“¬„®Õÿ¥µ—π (endotracheal tube obstruction) ´÷Ë߇ªìπº≈®“°°“√√–∫“¬‡ ¡À–·≈–°“√„Àâ
§«“¡™◊πÈ ·°àºªŸâ «É ¬‰¡à‡æ’¬ßæÕ„πºŸªâ «É ¬∑’„Ë à∑Õà ™à«¬À“¬„®
‡ªìπ‡«≈“π“π (prolonged intubation) Õ“®∑”„À⇰‘¥
postextubation subglottic stenosis, tracheal granuloma ‰¥â à«π vocal cord ¡—°®–∂Ÿ°∑”„À⇠’¬À“¬ ·≈–
‡°‘¥ palatal grooves ¢÷Èπ
ºŸâªÉ«¬∑’ˇªìπ chronic respiratory failure §◊Õ
µâÕß„™â‡§√◊ËÕߙ૬À“¬„®π“π‡°‘π 2-4 —ª¥“Àå §«√
æ‘®“√≥“∑’®Ë –„À⺪⟠«É ¬‡ª≈’¬Ë π¡“„™â tracheostomy tube
·∑π endotracheal tube ‡æ√“–®–∑”„À⺪Ÿâ «É ¬√Ÿ â °÷ ∫“¬
¢÷Èπ °“√À≈ÿ¥·≈–°“√Õÿ¥µ—π¢Õß∑àÕ‡°‘¥πâÕ¬°«à“ ∑”„Àâ
¥Ÿ·≈ºŸâªÉ«¬‰¥âßà“¬¢÷Èπ ·≈–ºŸâªÉ«¬¡’‚Õ°“ ∑’Ë®–À¬ÿ¥°“√„™â
‡§√◊ËÕߙ૬À“¬„®‰¥â¡“°¢÷Èπ
4. ¿“«–·∑√°´âÕπ∑’‡Ë °‘¥®“°°“√µ‘¥‡™◊ÕÈ (nosocomial infection)
¡’√“¬ß“π°“√‡°‘¥ ventilator-associated
pneumonia (VAP) „πºŸªâ «É ¬∑’„Ë ™â‡§√◊ÕË ß™à«¬À“¬„® Ÿß∂÷ß
√âÕ¬≈– 21-31 ·≈–‡ªì𠓇Àµÿ ”§—≠∑’Ë∑”„À⺟âªÉ«¬∑’ˇ°‘¥
respiratory failure ‡ ’¬™’«‘µ‰¥â∂÷ß√âÕ¬≈– 40-55 ¥—ßπ—Èπ
ºŸâ∑’Ë¥Ÿ·≈ºŸâªÉ«¬ §«√®–µâÕß≈â“ß¡◊Õ„Àâ –Õ“¥∑ÿ°§√—Èß°àÕπ
·≈–À≈—ß —¡º— À√◊Õ„Àâ°“√¥Ÿ·≈√—°…“ºŸªâ «É ¬ „™â‡∑§π‘§°“√
¥Ÿ¥‡ ¡À–∑’Ë∂Ÿ°µâÕß ‡«≈“∂Õ¥À√◊Õ„ à¢âÕµàÕµà“ßÊ ¢Õß
‡§√◊ËÕߙ૬À“¬„® §«√‡™Á¥¥â«¬·Õ≈°ÕŒÕ≈å∑ÿ°§√—Èß ‰¡à
§«√„Àâ¡π’ ”È ¢—ßÕ¬Ÿµà “¡ “¬ ‡ª≈’¬Ë 𠓬‡§√◊ÕË ß™à«¬À“¬„®
·≈–πÈ”„π humidifier µ“¡‡«≈“∑’Ë°”Àπ¥ ªÑÕß°—π°“√
Ÿ¥ ”≈—°‚¥¬‰¡à reintubation ºŸªâ «É ¬∫àÕ¬Ê ‰¡à‡§≈◊ÕË π¬â“¬
ºŸªâ «É ¬ÕÕ°®“°‡µ’¬ß‚¥¬‰¡à¡§’ «“¡®”‡ªìπ °“√„ÀâπÕπ„π
∑à“»’√…–¬° Ÿß 30 Õß»“
78
Pediatric Respiratory and Critical Care
‡Õ° “√Õâ“ßÕ‘ß
1. Essential Mechanical Ventilation for Infants and Children . Õ√ÿ≥«√√≥ æƒ∑∏‘æ—π∏ÿå, ¥ÿ ‘µ ∂“«√, ∏’√™—¬ ©—π∑‚√®π廑√‘, ∫√√≥“∏‘°“√. ™¡√¡‚√§√–∫∫
À“¬„®·≈–‡«™∫”∫—¥«‘°ƒµ„π‡¥Á°·Ààߪ√–‡∑»‰∑¬. °√ÿ߇∑æ : À.®.°. ¿“ææ‘¡æå. 2543.
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