低潮氣量通氣下肺保護策略 Low Tidal Volume (Lung Protective) Ventilation

低潮氣量通氣肺保護策略 (Low Tidal Volume (Lung Protective) Ventilation )

 

1. Consider Low Tidal Volume Ventilation in ALL patients with ARDS (Berlin Criteria)

✓ Timing within 1 week of clinical insult or new/worsening respiratory symptoms

✓ Chest XR shows bilateral opacities not fully explained by effusions, lobar/lung collapse, or nodules

✓ Respiratory failure not fully explained by cardiac failure/fluid overload

✓ PaO₂/FiO₂ ≤300 mmHg with PEEP OR CPAP ≥5 cm H₂O

 

2. Patients with the following conditions might NOT be suited for Low Tidal Volume Ventilation (ARDS Network

 

☐ Elevated intracranial pressure

☐ Neuromuscular disease that could impair spontaneous breathing

☐ Severe liver cirrhosis (Child–Pugh Class C

☐ Bone marrow transplant

☐ Severe metabolic acidosis

☐ Severe chronic lung disease (e.g. FEV1 <20ml/kg IBW, FEV1/FVC <50%, chronic hypercarbia PaCO2 >45mmHg and/or chronic hypoxemia PaO2<55mmHg, chronic lung disease resulting in severe exercise restriction

☐ Unsuited as judged by the attending physician:

 

 

3. Protocol

Ventilator	Sedation/Analgesia	Neuromuscular Blocking Agent (NMBA)
	Sedation: Midazolam :   IV infusion:  0.024 to 0.36 mg/kg/hour    Propofol :   5 mcg/kg/min; increase by 5 to 10 mcg/kg/min q 5 to 10 mins.   Usual maintenance dose: 5 to 50 mcg/kg/minute. Maximum dose  60 to 80 mcg/kg/min   Analgesia: Morphine :  0.01–0.5 mg/kg/hour infused IV, although higher (e.g., 150 mg/hour) Fentanyl :  0.7 to 10 mcg/kg/hr	1.     Achieve deep sedation (Ramsay 6) BEFORE initiation of NMBA 2.     Cis-atracurium : 15 mg bolus, followed by a continuous infusion of 37.5 mg per hour (or 0.03 to 0.6 mg/kg/hour ) 3.     Monitor Stop if FiO2 ≤0.4 and PEEP ≤8 cm for at least 12 hours

 

肌肉阻斷劑使用臨床照護與評估

★定期眼部潤滑和眼瞼閉合護理。

★    建議連續輸注 NMBA 而不是間歇性輸注 ★    避免在哮喘持續狀態下使用 ★    在低氧血症,呼吸性酸中毒和血流動力學受損等危及生命的情況下試用 NMBA ★    用理想體重計算的 NMBA 劑量 ★ 控制血糖值 < 180 mg/dL

★    神經肌肉阻斷之前和期間應同時併用鎮痛和鎮靜藥物 ★    採取措施降低接受 NMBA 的病人意外拔管的風險 ★    根據使用 PNS 減少重症肌無力病人的劑量 ★    在確定腦死亡之前停用 NMBA

 

 

Agent	Onset time	Infusion dose (μg/kg/min)	Clinical duration	Notes
Cisatracurium	4–7 min	1–3	35–50 min	Hofmann elimination

 

神經肌肉阻斷劑阻斷程度評估

Level of block	Depth of block	Objective measurement at APM
Level 5	Complete	PTC =0
Level 4	Deep	PTC≧1, TOFC=0
Level 3	Moderate	TOFC=1-3
Level 2b	Shallow	TOFR<0.4
Level 2a	Minimal	TOFR=0.4-0.9
Level 1	Adequate recovery	TOFR≧0.9

 

APM : adductor pollicis muscle, NMB : neuromuscular blockade, PNS :  peripheral nerve stimulator, PTC :  posttetanic count, TOF : train of four, TOFC :  train-of-four count, TOFR :  train-of-four ratio

不建議對神經肌肉阻滯的深度進行主觀評估，但可用於為從目前照護到最適合客觀監測的過渡評估。

 

Journal of Intensive Care volume 8, Article number: 37 (2020)