2产科困难气道_临床医学_医药卫生_专业资料
困难气道的分级
困难气道的分级介绍气道管理是医学中非常重要的一项技术，它涉及到保持患者的呼吸通畅，是抢救生命的关键。
然而，存在一些特殊情况，使得气道管理变得困难起来。
困难气道是指在气道管理过程中遇到的技术难题，既包括解剖因素引起的困难，也包括技术操作上的困难。
为了更好地应对困难气道，医学界将困难气道进行了分级，便于临床医生对患者进行评估和选择适当的气道管理方法。
困难气道的分级标准Mallampati分级法Mallampati分级法是最常用的评估困难气道的方法之一，它通过观察口腔内部的结构，进行分级。
分为以下四级：1.Mallampati I级：可以看到悬雍垂、腭弓和软腭。
2.Mallampati II级：可以看到悬雍垂和腭弓。
3.Mallampati III级：只能看到软腭的根部。
4.Mallampati IV级：看不到软腭，只能看到硬腭。
临床评估法除了Mallampati分级法外，还有一些其他的临床评估方法，如Thompson气道评估法、Wilson气道评估法等。
这些评估法通过观察患者的外部特征，如颈部活动度、颈部的可伸展性等来判断气道是否困难。
困难气道的原因解剖因素1.颈部和口腔结构异常：如颈部短粗、下颌后缩等。
2.颈部运动受限：如颈部肿瘤、外伤等。
3.颈部软组织肿胀：如颈部感染、创伤等。
技术操作因素1.操作者技术不熟练：操作过程中的过度推进、不正确的位置选择等。
2.呼吸道设备不合适：如喉罩通气、气管插管等使用不当。
困难气道的处理策略轻度困难气道轻度困难气道是指困难气道程度较轻的情况，可以通过一些简单的操作手段来解决，如：1.调整头位：将患者头部向后仰或向前屈，以改善气道的通畅性。
2.使用喉罩通气：喉罩通气是一种较为简单且安全的气道管理方法，适用于轻度困难气道患者。
中度困难气道中度困难气道是指需要更专业技术和设备来处理的情况，如：1.纤维支气管镜插管：通过纤维支气管镜引导气管插管，适用于困难气道患者。
2.气管切开术：在气管上部切开一小孔，插入气管切开管以通气，适用于严重困难气道患者。
困难气道
新型声门型气管导管
新型声门型气管导管
思考下面几个病例的气道处理
困难气道处理
袁瑞梅 2016-06-25
ASA
困 难 气 道 的 定 义
具有五年以上临床麻醉经验的麻醉医师在面罩 通气时遇到困难（上呼吸道梗阻），或气管插 管遇到了困难，或兼而有之
气管插管困难的预测
01
张口度
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甲刻间距
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Mallampatis试验
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Cormack分级
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颈椎活动度、脊髓损伤与否及平面
IMG_1033.MOV
• 插管条件不佳的患者： 小下颌 甲刻间距短 声门上抬 张口度小 颈部活动受限
经鼻盲探插管
快速诱导下控制呼吸经鼻盲探气管插管
IMG_1035.MOV
插 管 要 点
• 经鼻气管插管至14cm进入喉腔时，把气管 导管气囊充气10cm左右，接螺纹管进行手 控呼吸，在吸气时相缓慢插入，直至遇有阻 力止，如仍能顺利控制呼吸，则抽掉气囊的 气体，继续插入到气管内
导管1-2cm，并逆时针拧转气管导管，使气管导管头
端居中，在轻轻往下插直至插入。
清醒吸痰管导引经鼻盲探气管内插管
IMG_1038.MOV
清醒插管要点
• 表面麻醉：肾上腺素棉签鼻腔润滑，2%利多棉签鼻腔表麻，环甲 膜穿刺注入2%利多4ml，嘱用力咳嗽，使麻药均匀分布声门周围， 行双侧喉上神经阻滞 • 气管插管：经鼻插入14cm处，给气囊充气10-15ml，选择气流最 强烈时，用吸痰管从气管导管插入，在到气管导管口时，略停。 嘱病人用力呼吸，在吸气时顺势插入。如吸痰管进入气道，则无 阻力，放气，气管导管顺势插入。如有阻力，反复几次。注药利 用病人的吸气力，能把吸痰管如同异物一样吸入气道。
困难气道评估及处理
几种困难气管内插管的方法ቤተ መጻሕፍቲ ባይዱ
☆借助纤维喉镜或纤维支气管镜插管： 将气管导管套在镜杆外
面，然后按内窥镜操作原则 将纤维喉镜或纤维支气管镜 的镜杆送入声门，其后再沿 镜杆将气管送入气管内。
困难气道评估及处理
困难气道评估及处理
几种困难气管内插管的方法
☆经环甲膜穿刺置引导线插管法：
（1）经环甲膜穿刺将引导线（CVP导丝或硬膜外导管）逆 行经声门插入到口咽部，并将一端夹出。
（2）将气管导管套在引导线外，牵好导线两端，将气管导 管沿导线送过声门至气管内，然后拔出引导线（拔出 时注意固定好气管导管），再将气管导管向前推进2～ 3cm即可。
（3）此方法理论上是完全可行的，但临床上沿导线放置气 管导管时很易在会厌部受阻，需反复调节，始能成功。 操作时应轻柔，避免组织损伤。
困难气道评估及处理
困难气道的评估及处理
困难气道评估及处理
概述
☆困难气道定义（difficult airway） 困难气道是指在经过常规训练的麻醉医
师的管理下患者发生面罩通气和(或)气管插 管困难。
困难气道评估及处理
☆困难面罩通气（difficult face mask ventilation）
面罩通气困难是指在面罩给予纯氧和正压通气 的过程中由于以下一种或多种原因：不严密的 面罩接触、过多的气体泄漏、吸气或呼气时过 高的阻力，而出现通气不足，致使麻醉前SpO2 大于90％的患者无法维持在90％以上。
根据直接喉镜暴露下喉 头 结构的可见度进行分级 I 级:声门完全显露 Ⅱ级:仅见声门的后半部 Ⅲ级:仅见会厌 Ⅳ级:未见会厌
困难气道评估及处理
困难气道的管理
☆ 一般准备
▲ 告知病人或监护人 ▲ 准备气管插管器械 ● 各种规格喉镜和气管导管 ● 视频喉镜 ● 纤维支气管镜 ● 面罩 ● 喉罩
困难气道的处理方法ppt课件
蹦极 医疗 开车 麻醉 飞行 核电
1:100 1:1,000 1:10,000 1:100,000 1:1,000,000 1:10,000,000
插管困难的发生率
视觉困难 插管困难 插管失败 通气失败
2 - 10% 1 - 4% 0.1 - 0.3% 0.01 - 0.03%
标记声门的轮廓和紧邻后联合的杓会厌裂的 位置
分别叠加所有失败（59例）和成功插管（50 例）的绘图以辨别失败和成功插管时声门和 杓会厌裂所在的位置
记录方法
导管通过声门时的图像
左侧FZ失败区，右侧TZ为成功区
调整手法-插管过深调整
可将喉镜轻轻向喉旋转，然后树立喉镜并上提
Combitube 管
逆行插管
失败
气管切开
可视喉镜Ranger
Truview可视喉镜
微创气管切开术
经气管喷射通气技术
喉罩
纤支镜引导插管
硬纤维喉镜（Upsher镜）
SOS镜（Seeing Optical Stylet)
Shikani视可尼
视宁康
视频1 视频2
视宁康光学可视喉镜
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视宁康喉镜的构造
独特的角度设计，无需口，咽，喉三轴一线 视宁康喉镜的构造：两条通道，三大系统 插管有“道” 轻松可靠
喉镜下见部分会 厌，试插管失败
恢复自主呼吸， 置入探条 Bougie 盲插
失败
失败
置入插管喉罩 失败
面罩通气
失败
置入普通喉罩 失败
环甲膜穿刺， 气管切开
无禁忌症，喉罩下手术
成功 套入气管导管
纤支镜
失败
成功
通过喉罩 插管
失败
困难气道的特征
困难气道的特征
困难气道的表现形式有四种：面罩通气困难、喉镜暴露困难、气管插管困难和气管插管失败。
具体来说，困难气道主要具备以下特征：
1. 呼出二氧化碳消失或减少。
2. 胸廓运动消失或减弱，胸式呼吸运动存在或增强，出现矛盾运动。
3. 吸气运动困难，出现三凹征，声门下呼吸道塌陷、狭窄，表现为胸骨上窝、锁骨上窝及肋间隙向内凹陷。
4. 吸气期延长。
5. 吸气相可听到高调吸气性喉鸣音，严重时出现喘鸣音。
6. 呼吸音消失或减弱。
7. 脉搏氧饱和度下降，发绀，甚至意识丧失。
这些特征并不是一定都会出现，但在评估困难气道时应予以重视。
如果出现上述症状，应立即采取措施确保患者的呼吸道通畅，必要时应寻求专业医生的帮助。
困难气道
困难气道处理流程
优化头颈部体位的预充氧合 麻醉与诱导
仰卧嗅物位，单手扣面罩即可获得良好通气
置入口咽／鼻咽通气道单手扣面罩； 或单人双手托下颌扣紧面罩，即可获得良好通气 以上方法无法获得良好通气，需要双人加压辅助通气，能 够维持SpO2>90% 双人加压辅助通气下不能维持SpO2>90%
面罩通气分级
困难气道分类
困难喉镜显露：直接喉镜经过三次以上努力仍不能看到声带的任何 部分。 困难气管插管：无论存在或不存在气道病理改变，有经验的麻醉科 医师气管插管均需要三次以上努力。
气管插管
困难气道处理流程
6.紧急有创 气道的建立 5.声门上通气工 具的置入和通气 4.插管失败后面 罩通气
PART
04
术后随访和注意事项
PART
05
总结
总结
困难气道处理流程图
患者及家属知情同意
对已预知的困难气道患 者如何进行评估
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02
体格检查的内容
03 04
困难气道处理流程
①麻醉与气道管理前对患者进行详尽的评估与充分的准备， 对可疑困难气道患者建议使用辅助工具检查 。
困难气道处理流程
2.困难气道的分类 •已预料的明确困难气道 •未预料的困难气道
困难气道处理流程
2.困难气道的分类 •已预料的明确困难气道 ：
处理方法包括：①采用清醒镇静表面麻醉下实施气管插管，推荐使用 可视插管软镜等（如纤维支气管镜和电子软镜）可视 工具； ②改变麻醉方式，可采取椎管内麻醉、神经阻滞和局 部浸润等局部麻醉方法完成手术； ③建立外科气道。可由外科行择期气管切开术。
产科困难气道
J Anesth (2008) 22:38–48DOI 10.1007/s00540-007-0577-zReview articleManagement of the diffi cult and failed airway in obstetric anesthesiaG URINDER M. V ASDEV 1, B ARRY A. H ARRISON 2, M ARK T. K EEGAN 1, and C HRISTOPHER M. B URKLE 11 Department of Anesthesiology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA 2Department of Anesthesiology, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USAthrough his meticulous approach, superb clinical skills, and his renown from anesthetizing Queen Victoria [1]. In the 1950s, obstetric anesthesiologists recognized the need for the use of a cuffed endotracheal tube, as a result of Mendelson’s documentation of the problems of the pulmonary aspiration of gastric contents [2]. Later in the twentieth century, the specialty of obstetric anesthesia recognized the morbidity and mortality asso-ciated with diffi cult and failed intubation in obstetrics [3]. This led to the development of a “Failed intubation drill” by Tunstall [4] and the improvement of local anes-thetic agents and techniques [5]. Although obstetric anesthesia is, at times, infl uenced by fashions and trends, safety remains constant as the most important and central aspect of obstetric anesthesia. The maternal mortality rate is regarded as a direct indicator of the health-care of a nation. Estimated global maternal mor-tality is more than 500 000 per year [6]. Nearly 99% of this mortality occurs in developing countries and 1% in developed ones. In the United States, an article by Hawkins et al. [7] estimated that for the 1988–1990 tri-ennium the maternal mortality was 1.7 per million live births and during the same period the England and Wales maternal mortality was also 1.7 per million mater-nities. The most recent data, from the report on Confi -dential Enquiries into Maternal Deaths in the United Kingdom, demonstrated that there were seven cases of anesthetic-related maternal deaths during the 2000–2002 triennium and four of these were directly due to poor airway management [8,9].A 2003 analysis of the American Society of Anesthe-siologists (ASA) Closed Claims database revealed that 635 of the 5300 cases (12%) were associated with obstet-ric anesthesia care; 71% of these 635 cases were asso-ciated with cesarean section [10]. The most common claim was maternal death (22%), which was more fre-quently associated with general anesthesia than regional anesthesia. Critical events involving the respiratory system were the most common precipitants of injury inAbstract Diffi culty with airway management in obstetric patients occurs infrequently and failure to secure an airway is rare. A failed airway may result in severe physical and emotional morbidity and possibly death to the mother and baby. Additionally, the family, along with the medical and nursing staff, may face emotional and fi nancial trauma. With the increase in the number of cesarean sections performed under regional anes-thesia, the experience and training in performing endotracheal intubations in obstetric anesthesia has decreased. This article reviews the management of the diffi cult and failed airway in obstetric anesthesia. Underpinning this important topic is the difference between the nonpregnant and pregnant state. Obstetric anatomy and physiology, endotracheal intubation in the obstetric patient, and modifi cations to the diffi cult airway algorithms required for obstetric patients will be discussed. We emphasize that decisions regarding airway management must consider the urgency of delivery of the baby. Finally, the need for specifi c equipment in the obstetric diffi cult and failed airway is discussed. Worldwide maternal mortality refl ects the health of a nation. However, one could also claim that, par-ticularly in Western countries, maternal mortality may refl ect the health of the specialty of anesthesia.Key words Diffi cult airway · Failed airway · Obstetric anesthesiaIntroductionIn 1847 James Young Simpson (1811–1870) pioneered the concept of anesthesia and pain relief in childbirth. This idea, however, did not win immediate acceptance, owing to a major concern about “safety.” Within 10 years, John Snow (1813–1858) succeeded in lifting theo-retical restrictions on the use of obstetric anesthesiaAddress correspondence to : G.M. VasdevReceived: June 12, 2006 / Accepted: September 3, 2007these cases. Respiratory system problems included dif-fi cult intubation, aspiration, esophageal intubation, inadequate ventilation/oxygenation, bronchospasm, airway obstruction, inadequate fractional inspired oxygen (F i O2), seizures, and problems with equipment. Published incidences of diffi cult and failed obstetric airway are detailed in Table 1 [11–16]. The Cormack and Lehane laryngoscopy grade may be used to classify the diffi culty of intubation, and the grades are presented in Fig. 1. The contribution of airway diffi culties to maternal morbidity and mortality has heightened the awareness of the need for expert airway management in obstetrics.Anatomy and physiology of the obstetric airwayAn understanding of the anatomical and physiological changes in pregnancy aids the management of the problems associated with the obstetric diffi cult airway [17].The effects of estrogen and increased blood volume contribute to edema and friability of the upper airway mucosa. This change may cause nasal congestion and an increased risk of mucosal bleeding, especially with airway manipulation. Laryngeal edema can cause diffi -culty in passing the endotracheal tube. There have been a number of reports describing diffi culties with endotra-cheal intubation due to facial and laryngeal edema in patients with pre-eclampsia and eclampsia. Smaller-size endotracheal tubes should be used in obstetrics [18,19].As it enlarges, the gravid uterus displaces the dia-phragm cephalad and increases the abdominal circum-ference, while the hormonal changes induced by pregnancy increase the subcostal angle of the ribs. These factors result in the diaphragm and intercostal muscles contributing equally to the tidal volume. Anatomical changes lead to a 20% decrease in functional residual capacity (FRC), which can be decreased by another 25% when changing from the sitting to the supine posi-tion. This decrease is in the residual volume and the expiratory reserve volume. Pain and fatigue of labor can exacerbate the change in FRC. The decrease in FRC will accelerate the onset of oxygen desaturation during hypoventilation and apnea.There is no signifi cant alteration in total airway resistance during pregnancy. Chest wall compliance is decreased but lung compliance is unchanged. The net effect of these changes is a 50% increase in the oxygen cost of breathing. Ventilatory drive is increased during pregnancy, giving rise to hyperventilation. Progester-one is responsible for ventilatory stimulation but the specifi c mechanism is unknown [20]. Both oxygen con-sumption and carbon dioxide production are increased by 20%–40% at term.There is a delay in gastric emptying and a decrease in gastric pH during pregnancy. In addition, there is an increase in intragastric pressure associated with an incompetent gastro-esophageal sphincter. Heartburn occurs in 20% of pregnant women during their fi rst trimester, and in more than 70% of pregnant women during their third trimester [21]. A “full stomach” should always be a concern in this group of patients. While some of the changes associated with morbid obesity are similar to those seen in pregnancy, the two conditions are different and as such require differentTable 1.Incidence of diffi cult and failed obstetric airwayStudy Intubation measurement Obstetric incidenceGeneral incidenceCormack and Lehane [12]Diffi cult: laryngoscopic view, grade 3 1 : 2000Yeo et al. [16]Diffi cult: laryngoscopy, grade 3, 4 1 : 46 (2.1%) Gynecologic 1 : 56 (1.8%) 1 : 50 (2.0%) Lyons [13]Failed 1 : 300 (0.33%)Samsoon and Young [15]Failed 1 : 283 (0.35%) 1 : 2230 Rocke et al. [14]Failed 1 : 750 (0.13%)Benumof [11]Cannot ventilateCannot intubate0.001%–0.02%Fig. 1.Illustrates a diffi cult airway defi ned by the laryngeal view on laryngoscopy [15]. Reprinted with permissionsolutions. For example, because adipose tissue has a lower metabolic rate compared to other tissues the increase in oxygen consumption seen in obesity is pro-portionally less than the increase in weight. Oxygen consumption expressed per kilogram is less in the obese patient than in the parturient [22]. In contrast, the decreased FRC and increased oxygen consumption seen in the obstetric patient is more reminiscent of the neonate than of the obese patient.Endotracheal intubation in the obstetric patient IndicationsApart from endotracheal intubation for elective cesar-ean section under general anesthesia and postpartum procedures, e.g. tubal ligation under general anesthesia, all other intubations are performed as emergencies. During emergency endotracheal intubation, a full airway assessment may not be performed and the avail-ability, appropriateness, and function of induction drugs, monitors, and other equipment may not have been checked. Preexisting and pregnancy-related diag-noses, maternal hypovolemia, or coagulopathy may not be fully appreciated. Skilled help may not be readily available. These factors mean that establishing an airway in the emergency setting poses a higher risk than in an elective setting.General anesthesia for cesarean section, often in the setting of fetal distress, is the commonest indication for endotracheal intubation in the obstetric patient. However, a failed regional technique, high spinal or high epidural block, local anesthetic toxicity, cardiac arrest, and respiratory and neurological emergencies may each result in the need for endotracheal intubation. The pur-ported advantages of general anesthesia include a faster onset and less hemodynamic disturbance. However, regional techniques are advocated by some experts who believe that they are associated with better outcomes than general anesthesia, especially with respect to the baby [23]. A recent Cochrane systematic review of regional versus general anesthesia for cesarean section included elective and urgent cases. The techniques did not differ in the resultant umbilical arterial pH. Results from the analysis of umbilical venous pH favored the regional group, but the numbers were small and the values were above the cutoff for acidosis. Although the reviewers found that the mean Apgar scores at 1 and5 min favored the regional group, when Apgar scores of6 or less were analyzed there was no difference between the regional and general anesthetic groups [24]. Obstetric airway assessmentAn adequate airway assessment prior to all anesthesia and analgesia procedures on the labor fl oor is essential.A complete assessment can be performed in approxi-mately 1–2 min. Table 2 outlines a scheme for airway assessment, while Fig. 2 demonstrates the Mallampati classifi cation [25]. Some advocate that all patients on the labor fl oor should undergo an airway assessment examination on admission. The American College of Obstetricians and Gynecologists recommends that the obstetric care team should “be alert” for the general anesthesia risk factors, and if present, specialist consul-tation should be obtained, and consideration be given for the placement of an epidural catheter in early labor [26]. In assessing the obstetric airway it is important to take into account maternal congenital abnormali-ties; for example, Noonan syndrome, Pierre Robin syn-drome, hereditary telengiectasis, and neurofi bromatosis. Important acquired maternal conditions include pre-eclampsia, morbid obesity, and obstructive sleep apnea. Both congenital and acquired conditions may contrib-ute to the diffi cult obstetric airway.Table 2.Essentials of airway assessment1Facial edema2Obesity and short neck3Neck fl exion and extension-atlanto-occipital extension 4Mandibular space-thyromental distance5Mouth opening6Dentition—protruding maxillary incisors, missing teeth 7Oropharyngeal structures—Mallampati classification Fig. 2.Mallampati classifi cation [15]. Reprinted with permissionUnfortunately, only a few obstetric studies have eval-uated airway assessment prospectively. Rocke et al. [14] performed an airway assessment in 1500 parturients undergoing emergency and elective cesarean section under general anesthesia. This group discovered a strong correlation between oropharyngeal structures and the laryngoscopy view and diffi culty at intubation. Multi-variate analysis demonstrated that failure to visualize oropharyngeal structures, and the presence of a short neck, receding mandible, and protruding maxillary inci-sors were associated with a less favorable laryngoscopy view. It is important to note that one of the endpoints in this study was diffi cult intubation, as judged by a scoring system developed by the authors. In this study there were only two cases of failed intubation, giving an incidence of 1 : 750 or 0.13%. Yeo et al. [16] demon-strated that the Mallampati score was predictive of a diffi cult intubation. Their endpoint was the laryngeal view. However, in their study, intubation diffi culty was observed even in some patients with Mallampati grade 2 views.Preparation for intubationA prophylactic regimen to neutralize and minimize stomach acid is usually administered in an effort to decrease the risk of pulmonary aspiration of gastric contents in pregnant women. The nonparticulate antacid sodium citrate (0.3 M) and the H2-receptor antagonist ranitidine are administered to neutralize the stomach’s acidity and prevent further gastric acid pro-duction. Metoclopramide will facilitate gastric emptying and raise the gastro-esophageal sphincter tone [27–29]. Although these are “time-honored practices” the end-points used to measure the effi cacy are usually secondary. Because of the low incidence of aspiration pneumonitis, it is diffi cult to prove that these medica-tions decrease the incidence or improve the outcome of the complication.While it may seem obvious, it is vital that all essential monitoring, drugs, and equipment must be checked and ready prior to any regional or general anesthetic proce-dure in the obstetric operating room. Emergency airway adjuncts, such as oral and nasal airways, endotracheal tube stylets, gum elastic bougie, light wand, and a fi ber-optic intubating device should be readily available. Endotracheal intubationPaying close attention to all aspects of the performance of endotracheal intubation is especially important in obstetric anesthesia, and in some cases modifi cation of the technique may be required [17]. The patient needs to be correctly positioned. The neck needs to be fl exed at the cervico-thoracic junction and extended at the atlanto-occipital joint. Properly positioned pillows help to exaggerate the position by bringing the anatomi-cal axes into line while optimizing and improving success [30]. At least 3 min of inspiring 100% oxygen with an anesthesia closed-face mask is the ideal for the denitro-genation technique. When time is limited, four deep breaths (DB), i.e., vital-capacity breaths of 100% oxygen (4 DB/30 s) or 8 DB in 60 s (8 DB/60 s) can be used [31,32].General anesthesia is usually induced intravenously with thiopental, propofol, or ketamine. Cricoid pressure should be in position at the onset of induction and fully applied as the patient is induced. There may be diffi culty inserting the scope due to poor positioning of the patient, the size of the chest wall and breasts, and improperly positioned cricoid pressure. Surprisingly, there has been no study suggesting which laryngoscope blade is optimal. At present the recommendation is that the blade with which the operator is most familiar should be used. Following endotracheal intubation, con-fi rmation is necessary by quantitative and qualitative measurement of end-tidal CO2.Stress and the obstetric airwayPsychological stresses involved in the diffi cult airway in obstetrics have been largely ignored. Obstetrics is one of the few areas of medicine where there is a “true” emergency. There are two lives at risk, those of the mother and the baby. Not uncommonly, the anesthesi-ologist is an infrequent practitioner in the labor ward and is not completely comfortable with obstetric prac-tice or the pathophysiological changes of the mother and baby. Sometimes the practitioner can be one of the most junior of the anesthesia care team. The access to skilled help can be limited. There has also been a decrease in the number of cesarean sections performed under general anesthesia, leading to a decrease in expe-rience, both at the consultant and trainee level [33]. All these factors precipitate stresses that have the potential to infl uence the behavior of the obstetric anes-thesiologist at the most crucial time—during the man-agement of the airway. Although the impact of the psychological stress has been ignored, diffi cult airway algorithms and education regarding the cognitive and technical skills required for the diffi cult airway help to alleviate these stresses and prepare the anesthesiologist in managing the diffi cult obstetric airway.Diffi cult airway algorithms and failed intubation drills ASA diffi cult airway algorithmThe ASA diffi cult airway algorithm has standardized the approach to the diffi cult airway [34]. Such stand-ardization aims to minimize the morbidity and mortalityassociated with the diffi cult airway and aids in education and research. However, the ASA diffi cult airway algo-rithm needs to be adapted for obstetric patients.Signifi cant differences between the obstetric and ASA algorithms include:1. M ost obstetric cases are emergency rather than elective2. C onsiderations related to maternal, uterine, and fetal physiology3. I n obstetrics, both the mother and the fetus need to be assessed and considered4. S pontaneous breathing is preferred in the nonobstet-ric patient In the same manner as for the ASA diffi cult airway algorithm, initial assessments are required and subse-quent decisions are made based on these assessments. The initial assessments include evaluation of the mater-nal airway and fetal status. The clinician needs to decide whether the airway is diffi cult, as an expected diffi cult airway is easier to manage than an unexpected diffi cult airway. If one is faced with an “expected diffi -cult airway,” the next decision is whether to perform a regional technique versus an awake-intubation tech-nique, and if an awake-intubation is chosen, whether to perform a surgical technique versus a non-surgical technique.Cardiac arrestAs diffi cult or failed intubation may lead to cardiac arrest, the potential for maternal cardiac arrest must be assessed. Aspiration and lung injury will exacerbate the hypoxia of the diffi cult and failed airway, further increasing the potential for cardiac arrest. Protocols for cardiopulmonary resuscitation in pregnancy advocate perimortem cesarean delivery within 5 min of cardiacarrest [35]. In the diffi cult or failed intubation, earliercesarean section may aid resuscitation.Obstetric diffi cult and failed airway algorithmsThere are a number of diffi cult and failed obstetric airway algorithms. Most are complicated, aiming to cover all contingencies [30,36,37]. The nature and quality of evidence for these algorithms is not stated and they are based mainly on a compilation of case reports. Importantly, there is no evidence of effective-ness. The development of a simpler algorithm may increase its ease of use and allow a determination of the algorithm’s effectiveness. The desire for the development of a simple algorithm has led to the intro-duction of “drills” to be used in the event of a failed-intubation in an obstetric patient. A 17-year review of a failed-intubation drill at St. James’s University Hospital in the United Kingdom illustrated some of the benefi ts of this approach [38]. Of 5802 cesarean sections between 1987 and 1994, there were 23 (0.4%) failures to intubate the trachea. The algorithm used was simple and specifi c for unexpected failed intubation. Most of the failures were for emergency situations. Eighteen patients were allowed to waken and regional techniques utilized. Manual ventilation was diffi cult in 7 patients and impossible in 2. Four patients had a laryngeal mask airway (LMA) inserted. Using the LMA in this situation, the lungs were diffi cult to ventilate in two episodes and impossible to oxygenate on one occasion.No anesthesia or obstetric anesthesia association or society has developed evidence-based guidelines for the obstetric diffi cult airway or failed obstetric intubation. Approaches to the expected and unexpected diffi cult airway are outlined in Figs. 3 and 4, respectively. The guidelines are intended to promote discussion of airway management techniques.Expected difficult intubationRegional anesthesia Non surgicalFiberoptic - specialized laryngoscope - lighted stylet - LMA, ILMAAwake intubationNon fiberopticSurgicalFig. 3. Algorithm for expected diffi cultintubation. LMA , laryrigeal mask airway; ILMA , intabating LMAExpected diffi cult intubationOnce the assessment has determined that the airway is expected to be diffi cult, a decision must be made between the use of regional anesthesia for the patient or an awake intubation followed by general anesthesia. If awake intubation is decided upon, a surgical or non-surgical technique must be chosen. For the obstetric diffi cult airway an awake surgical airway is of limited utility. Most likely the technique would be of benefi t in a parturient who has suffered upper airway trauma or when an obvious pre-existing airway problem exists. There have been two case reports describing insertion of tracheotomy prior to delivery [39,40]. In one case the patient subsequently underwent cesarean section under regional anesthesia with the tracheotomy used as a backup. In the other case, the parturient underwent an elective tracheotomy due to her past medical history of diffi cult and failed intubation attempts.Regional anesthesia and the diffi cult obstetric airway Regional anesthesia is usually selected in the case of an airway that is expected to be diffi cult. In nonemergency obstetric situations, the choice of a regional technique is dependent on anesthesiologist and patient preference and characteristics. In emergency situations, when rapid attainment of surgical conditions is required, general anesthesia may be chosen. However, the need to swiftly attain surgical anesthesia is not a contraindication to a regional technique in the hands of an experienced anesthesiologist. The only absolute contraindications to regional anesthesia in obstetrics are patient refusal and coagulopathy. This is especially important in the case of an anticipated diffi cult airway, where a regional tech-nique may be advantageous. Although the literature suggests that outcomes are equivalent after regional or general anesthesia in emergency situations, there is no literature to support the optimal regional technique.Although “conventional wisdom” endorses a regional technique in the expected diffi cult airway, complications or failure of the regional technique may make it neces-sary to intubate the trachea. Thus, a backup plan is nec-essary, with the availability of appropriate equipment. Hawksworth and Purdie [41] described a patient with a failed combined spinal epidural technique who failed an endotracheal intubation, and was then woken up and underwent an awake fi beroptic intubation. This is one of many case reports illustrating the potential dif-fi culties of regional anesthesia. When deciding on the regional technique, it is important to select the technique that minimizes the potential for airway, cardiac, and respiratory emergencies for the individual parturient.Unexpected difficult intubationManual ventilationYes Urgent delivery LMA, CombitubeYesmask ventilation, LMAregionala i s e h t s e n a intubationpr o ceed wake o t surgery patientregional anesthesiaor awake intubationTTJV No wake patient up urgent delivery No NoYesawake Fig. 4. Algorithm for unexpected diffi cult intubation. TTJV , transtracheal jet venti-lation. Combitube (Kendall-Sheridan Catheter, Argyle, MA, USA)Awake intubation techniquesLocal anesthesia and the upper airwayLocal anesthesia plays an important role in the success of an awake intubation technique. It is necessary to provide adequate upper airway anesthesia before every awake intubation technique. The use of selective nerve blocks or direct application of local anesthetic agents will provide adequate anesthesia of the upper airway. The hormonal changes in pregnancy increase the sensi-tivity of peripheral nerves to local anesthetic agents [42]. In pregnancy, the upper airway membranes have increased vascularity, increasing the uptake and decreas-ing the duration of action of the local anesthetic. Thus, these two factors may balance out. However, it is impor-tant to be vigilant for local anesthetic toxicity. The local anesthetic agent prilocaine may induce a dose-related methemoglobinemia. The fetus may be more susceptible because of immature reductase enzyme pathways that predispose it to methemoglobinemia from oxidizing agents such as metabolites of prilocaine [43].Awake nonfi beroptic intubation techniquesThere are many techniques for awake nonfi beroptic intubation. These vary from basic to more modern tech-niques. Different-sized Macintosh and Miller laryngo-scope blades, as well as specialized laryngoscopes with fi beroptic light sources of different shapes can be used. Airway adjuncts, such as stylets, intubating bougies, and external manipulation of the larynx may all play a role in aiding intubation. The lighted stylet can also be used as a means to secure an “awake” airway without need for use of a fi beroptic bronchoscope. Although blind nasal intubation can be used, bleeding from the vascular membranes may further complicate the already diffi cult intubation.The LMA, intubating laryngeal mask airway (ILMA), or the ventilating LMA can be used for awake airway management. The ILMA is probably the preferred choice, as a defi nitive cuffed airway can be readily intro-duced. There are case series and case reports describing the use of the ILMA and one case report describing the use of the LMA to facilitate awake endotracheal intuba-tion in obstetric patients with diffi cult airways [44–46]. There are no reports of the use of the ventilating LMA for awake airway management in obstetrics.Awake fi beroptic intubationFiberoptic scopes may be nonfl exible or fl exible. Of the nonfl exible scopes, only the Bullard has been reported to have been used in an awake obstetric patient with a diffi cult airway [47]. Flexible fi beroptic intubation tech-niques are popular for the expected diffi cult airway, especially in the parturient. Fiberoptic techniques require expensive equipment that may not be easily portable and may have steep training curves. The fi ber-optic devices should allow the delivery of supplemental oxygen, as hypoxia is a common complication during these procedures.There are multiple case reports describing the success of fi beroptic bronchoscope-guided intubation in both the expected and the unexpected diffi cult obstetric airway. These reports describe the use of the fi berscope in patients predicted to have a diffi cult airway based on preoperative evaluation, as well as in those patients in whom obvious defects were present, includ-ing congenital facial abnormality, goiter, and odontoid fracture [48–53]. Some anesthesiologists prefer awake fi beroptic intubation over regional anesthesia in the predicted diffi cult airway parturient [54]. They argue that the use of regional anesthesia in a patient with an expected diffi cult airway does not solve the airway problem, and complications from regional anesthesia can lead to an emergency diffi cult airway situation. However, the failure and complication rates of awake fi beroptic intubation in the parturient are unknown. Potential complications include hypoxia, trauma to the laryngeal structures, and bleeding from the vascular membranes, especially if the nasal route is chosen. Diffi culty in passing the endotracheal tube may be seen in pre-eclampsia, where patients may have laryngeal edema.Retrograde intubation techniqueA retrograde intubation technique can be utilized in the expected or unexpected diffi cult obstetric airway. When an awake fi beroptic intubation technique has failed, bleeding and edema may result, increasing the diffi culty of subsequent attempts. A retrograde technique may be useful in this scenario [55]. Once the guidewire has been passed through the cricothyroid membrane and has exited the mouth or nose, it can be threaded up the suction channel of the fi beroptic scope. The fi beroptic scope is then advanced along the guidewire under direct vision through to the trachea.Unexpected diffi cult intubationWith a nonobstetric unexpected diffi cult airway, demon-stration that mask ventilation is possible is performed before the administration of neuromuscular blockers and an attempt at intubation. In obstetric anesthesia, a rapid sequence induction is usually performed due to the aspiration risk; thus, it is unknown whether mask ventilation is successful before intubation attempts. When intubation is diffi cult, as demonstrated by the laryngeal view, or when there is failure to intubate, mask ventilation must be attempted to ensure oxygenation and ventilation. Because of the increased weight in。
困难气道操作处理护理课件
由于呼吸道不通畅，可 能导致血氧饱和度下降。
如喉痉挛、心律失常等。
02 困难气道操作处理
评估与诊断
01
02
03
病史采集
了解患者是否有困难气道 相关病史，如颈部手术、 气管异常等。
体检
观察患者颈部活动度、张 口度等，评估气道通畅程 度。
辅助检查
通过喉镜、X线、CT等手 段进一步评估气道状况。
问题三：并发症发生
对策：密切监测患者生命体征，及时 发现并处理并发症，如出血、水肿等。
经验教训与改进措施
经验教训
总结操作过程中的不足和错误，分析 原因。
改进措施
根据经验教训，提出改进方案，优化 操作流程，提高处理效率。
05 困难气道操作处理的发 展趋势与展望
新技术新方法的探索与应用
1 2 3
视频喉镜 随着视频喉镜技术的发展，其在困难气道处理中 的应用越来越广泛，能够提供更好的视野和操作 便利性。
告知患者及家属
向患者及家属详细介绍手术及麻醉 相关知识，减轻他们的焦虑和恐惧， 并签署知情同意书。
术中护理配合
监测生命体征
在手术过程中密切监测患者的生 命体征，包括心率、血压、呼吸 等，及时发现并处理异常情况。
协助医生操作
根据医生的要求，协助进行呼吸 道管理、呼吸机设置等操作，确
保手术顺利进行。
记录护理记录
紧急处理措施
面罩加压给氧
在无法建立有效通气时， 立即使用面罩加压给氧， 以维持氧供。
环甲膜穿刺
在紧急情况下，可进行环 甲膜穿刺以建立通气通道。
紧急气管切开
在无法通过面罩或环甲膜 穿刺建立通气时，应考虑 紧急气管切开。
特殊处理方法