第二章笔记:
1 虽然吸烟停止后12h,碳氧血红蛋白含量即显著下降,但行心脏手术患者,需戒烟2个月以上才会对术后肺功能有所改善,其主要原因与粘膜纤毛功能改善有关。
2 在纵隔镜检查过程中,压迫你或阻塞无名动脉,所以袖带应绑在左臂,氧饱和度置于右手。
3 支气管镜检查过程中,气管软骨环可作为定位的标志,气管软骨环位于前方,通过其与主支气管的关系来确定左侧还是右侧。
4 缺氧性肺血管收缩(HPV): 低FiO2,低流量通气,肺不张→PaO2降低→肺动脉平滑肌细胞的O2感受器→血管阻力增加,血液流向通气好的区域。作者: yihui36 时间: 2012-2-19 00:49
第三章笔记
1 Mendelson 综合征是由于细支气管受到胃酸的刺激→支气管痉挛、支气管周围渗出与出血。
2 PH值>2.5,与吸入蒸馏水相同。量>25 mL (0.4 mL/kg) pH 值 < 2.5引发Mendelson 综合征。
3 You suspect the patient has aspirated. What is your initial
management strategy?
1 30-degree head-down position 2 maintains cricoid pressure 3 suction the mouth and pharynx as rapidly as possible.4 endotracheal intubation inflation of the endotracheal cuff to prevent further aspiration. 5 Quickly suction through the
endotracheal tube before administering 100% oxygen by PPV. prevent pushing aspirated material beyond your reach. Suction should be brief to avoid cardiac arrest from hypoxia. Give 100% oxygen before and after suctioning. 6 An orogastric tube should be inserted 7 If bronchospasm is noted, β 2-agonists 8 Early application of PEEP
4 Prophylactic antibiotic(预防性使用抗生素) has not been shown to improve mortality or reduce secondary infection rates. Cultures must be taken as soon as possible after aspiration and thereafter as clinically indicated
However, if intestinal obstruction (肠梗阻)is a possibility, antimicrobial therapy(抗菌药物治疗) for the possibility of anaerobic(厌氧菌) and gram-negative infection may be warranted(合理的).
5 关于激素的使用
Controversial
In experimental studies,When the pH value of the aspirate was in the narrow range of 1.5 to 2.5,corticosteroid therapy(激素治疗) was beneficial in treating acid-aspiration pneumonitis.Dexamethasone(地塞米松), given 0.08 mg per kg every 6 hours。When the pH value of the aspirate was
less than 1.5, the pulmonary parenchymal damage was maximal. Therefore, the steroid therapy was not effective.When the pH value of the aspirate was higher than 2.5, the response was similar to that of water.
because of the failure of two multicenter, randomized, controlled trials to
demonstrate a benefit of high-dose corticosteroids in patients with ARDS, the administration of corticosteroids cannot be recommended.
6 关于碳酸氢钠或生理盐水灌洗
No.(a) the large volume of fluid served to push the hydrochloric acid deeper into the lungs(b)mixing of the acid and treatment solution was impossible
(c) hydrochloric acid(盐酸) probably causes damage within a very short time
(d)the pH value increases only to 1.8
(e) produces heat, and a thermal burn of the bronchial mucosa may occur
Bronchial irrigation(支气管灌洗) is indicated only in the obstructive type(梗阻型) of aspiration
7 预防
a wide-bore orogastric tube
regional anesthesia
antacid, such as 30 mL of 0.3-M. sodium citrate(柠檬酸钠)
anticholinergic agents(抗胆碱药)
metoclopramide(胃复安) to stimulate gastric emptying and to increase lower
esophageal sphincter tone(食管括约肌张力)
H2-receptor antagonist or proton inhibitors(质子泵抑制剂)
Extubation only when the patient is fully awake
8 保护性通气策略
lower inspiratory driving pressures (< 20 cm H2O above PEEP)
lower tidal volumes (6 mL/kg)
permissive hypercapnia over higher airway pressures
sedation to improve patient-ventilator synchronization
judicious use of PEEP作者: yihui36 时间: 2012-2-19 17:32
第三章笔记
9 急性肺损伤的病理生理:hyaline membrane(透明膜), alveolar hemorrhage, increased
endothelial and epithelial permeability(内皮细胞和上皮细胞的通透性增加),neutrophilic infiltration(中性粒细胞浸润)
机制:Increased permeability→passage of protein-rich plasma both in the alveolar and in the interstitial spaces(间质)→ poor lung compliance and ineffective gas exchange
加上 alveolar surfactant content ↓
filled with fibrin and other cellular materials
最终 collagen(胶原) deposition and pulmonary fibrosis.
Complement activation(补体活化) may also play a major role
Cyclic opening and closing of these alveolar units has been implicated as a cause of
ventilator-induced lung injury
10 ARDS的PEEP设定
On a static pressure-volume curve, the determination of this lower inflexion point (LIP)(低位拐点) allows the clinician to set the positive end-expiratory pressure (PEEP) to 2 cm H2O above this critical opening volume to prevent alveolar collapse and promote recruitment.
The ideal tidal volume can be extracted from this exercise as the volume contained between the LIP and the UIP(高位拐点)
11 双相正压通气(BiPAP)
BiPAP is typically reserved for patients who are experiencing mild to moderate
respiratory failure and who are not at increased risk of aspiration
12 Rapid shallow breathing index =respiratory rate/tidal volume>200 breaths per
minute per L
13 关于机械通气支持
In patients with markedly increased work of breathing, hypervolemia(血容量过多), or impaired left ventricular pump function, the institution of mechanical ventilatory support can be life saving because of its ability to support the cardiovascular system, independent of any beneficial effects that mechanical ventilation may have on gas exchange. In patients with decreased pulmonary elastic recoil(弹性回缩力), increased pulmonary vascularresistance, hypovolemic, or airflow obstruction, the institution of mechanical ventilatory support may induce cardiovascular instability, which if not corrected can lead to total cardiovascular collapse.
When pulmonary compliance decreases, the transmission of airway pressure to intrathoracic pressure decreases
14 高氧损伤
Retrolental fibroplasia (retinopathy of prematurity(早产儿视网膜病变)) in the premature neonate has been reported after exposure to PaO2 at more than 80 to 150 mmHg for a few hours
the adult patient can generally tolerate 1 atmosphere of oxygen partial pressure for at least 24 hours.
bronchiolar and tracheal ciliated cells(气管支气管纤毛细胞) can be damaged by 80% to 100% oxygen
15 PEEP改善氧合的机制:
an increase in the FRC and redistribution of extravascular lung water
16 最佳PEEP
More recently, the endpoint for PEEP application is the lowest level of PEEP that provides an adequate PaO2 at an FIO2 of less than 0.5作者: yihui36 时间: 2012-2-19 23:26
17 NO(一氧化氮)的作用机制:
diffuses into vascular smooth muscle→activates soluble guanylate cyclase(可溶性鸟苷酸环化酶)→ ↑intracellular cyclic guanosine monophosphate (cGMP)→smooth muscle vasodilation
nitroglycerin(硝酸甘油) and nitroprusside(硝普钠) also act through guanylate cyclase activation to directly release NO.
Inhaled NO is a selective pulmonary vasodilator.NO is not effect ive during systemic
administration because it is rapidly inactivated by hemoglobin
Inhaled NO may decrease pulmonary hypertension and improve oxygenation in patients with ARDS because inhaled NO may be distributed according to ventilation so the associated vasodilation increases blood flow to well-ventilated alveoli.
selective enhancement of hypoxic pulmonary vasoconstriction by phenylephrine(新福林), complements selective vasodilation by inhaled NO