王斌气管食管瘘分析解析.ppt

Tracheoesophageal Fistula 气管食管瘘 王 斌,Case,A 12-hour-old full term infant， weighing 2.5 kg presents with choking（窒息） and cyanosis （发绀） during its first feed. Neonatal （新生儿） intensive care unit (NICU) staff is unable to pass a feeding tube into the stomach. The baby also has copious（大量的） oral secretions （分泌物）. Before birth polyhydramnios （羊水过多） was seen.,1. What are the clinical features of TEF?,This patient has esophageal atresia(食管闭锁) with tracheoesophageal fistula（TEF）. This occurs in 1 per 4,000 live births. The diagnosis is suspected prenatally（产前） by the presence of polyhydramnios caused by failure of the fetus(胎儿) to swallow amniotic fluid（羊水） (secondary to esophageal atresia). After birth, the neonate will have copious drooling（流涎）. Attempting to feed the baby will result in coughing and cyanosis. An orogastric tube (口胃管) will coil up in the upper esophageal pouch（盲端） rather than pass into the stomach.,2. What is the pathophysiology of TEF?,In this abnormality the distal(远端，末梢) trachea（气管） is connected to the lower esophagus（食管） through a fistula. This causes three problems. First, inhaled air can bypass the lungs and distend（膨胀） the stomach, which will eventually impede ventilation and cause atelectasis（肺不张）. Second, acidic stomach contents are at continual risk of leaking back into and damaging lung tissue. Third, oral secretions tend to pool（聚集） in the proximal（近端） esophageal pouch resulting in intermittent aspiration, coughing, and cyanosis.,3. How does this lesion occur during development?,The median ventral diverticulum（腹侧正中憩室） of the foregut(前肠) differentiates into a separate（隔） esophagus and trachea by the end of the fifth week of gestation（怀孕）. The fistula comes from respiratory tissue. Bolstering（支持） this conclusion is the finding that the fistula expresses thyroid transcription factor-1 (TTF-1，甲状腺转录因子-1), which is found only in respiratory tissue of the foregut. The fistula is not an esophageal structure, despite superficial resemblance.,4. How are types of TEF classified?,There are five types of TEF according to the classic Gross classification. Type A is pure esophageal atresia (食管闭锁) with no involvement of the respiratory tree. This occurs in 8% of cases. Type B has esophageal atresia and a fistula connecting the proximal esophageal pouch（近端食管盲端） to the trachea. This occurs in less than 1%. The most common is type C with esophageal atresia and fistula linking the distal esophagus（远端食管） to the trachea. This occurs in 75% to 80% of cases.,Rarely, type D occurs with two fistula connecting both proximal and distal esophagus to the trachea (2%). Type E, known as an H-type fistula has no atresia, and it occurs in 4%.,5. What other problems may this child have?,Unfortunately， TEF often does not occur in isolation. Serious additional anomalies（畸形） can occur in the spectrum known as VACTERL. V = vertebral anomalies (脊柱畸形) A = anal canal defect (anal atresia 肛门闭锁) C = cardiac malformation（心脏畸形） (ventricular septal defect VSD, atrial septal defect ASD, Tetralogy of Fallot TOF, right sided arch(右位主动脉弓), patent ductus arteriosus PDA) TE = TEF R = renal dysplasia（肾发育不良） L = limb defect (radial aplasia桡骨畸形),6. What laboratory workup should be obtained before surgery?,Firstly, one must assess the presence and severity of pulmonary disease（肺部疾病）, especially looking for aspiration pneumonia（吸入性肺炎）, and respiratory distress （呼吸窘迫）associated with prematurity（早产）. Plain chest x-ray may show infiltrates（浸润影）. A radio-opaque orogastric tube (OGT) will be coiled in the proximal esophageal pouch, whereas an abdominal x-ray may show air in the bowels entering through the fistula. Because of the risk of aspiration, use of contrast dye（造影显影剂） to delineate（显示） the fistula should be used only when there is diagnostic uncertainty.,Second, an echocardiogram（超声心动图） is mandatory as major cardiac defects strongly influence survival and may impact on anesthetic management. Spinal plain films should be done to exclude vertebral anomalies, especially if epidural（硬膜外） pain management is being considered. Renal ultrasound should be done to rule out abnormalities, especially hydronephrosis（肾积水）. In addition, complete blood count (CBC), arterial blood gas, and electrolytes should be drawn.,7. Describe management in the NICU before surgery,After diagnosis of TEF is established and other coexisting anomalies investigated, the baby should be immediately made NPO (nothing by mouth). He should be kept in a warmed isolette（保温箱） with the head elevated at least 30 degrees to minimize reflux（反流） through the fistula. An nasogastric tube (NGT) should be placed in the proximal esophageal pouch and kept on intermittent suction（吸引） to minimize aspiration of oral secretions. Antibiotics（抗生素） to treat aspiration pneumonia should be given when appropriate.,Ampicillin（氨苄西林） and gentamicin（庆大霉素） should be given in those patients who have coexisting significant cardiac disease as prophylaxis（预防）. Ensure that blood is available from the blood bank（血库）. Because the patient will require a thoracotomy（胸廓切开术） with lung retraction（肺萎陷） and intermittent compression of the trachea and great vessels, an arterial line（动脉导管） is mandatory for the case. This should ideally be placed in the NICU. Two additional IV lines should also be placed, as the patient will be NPO.,8. Should these patients be routinely intubated preoperatively for airway protection?,Unless mandated by severe pulmonary disease, the child is not intubated routinely preoperative to minimize the possibility of gastric distension（胃扩张） from positive pressure ventilation （PPV，正压通气） through the fistula（瘘）. It is noted that intubation does not protect the child from aspiration of gastric contents through the fistula.,9. What IV access and monitoring are appropriate before induction? After induction?,At least one peripheral（外周） IV should be in place before induction. A second may be placed after patient is anesthetized. If the surgeon intends to give the child total parenteral nutrition (TPN，全胃肠外营养) postoperatively, a central may be placed. Arterial line placement for blood gas and hemodynamic monitoring should be placed before incision if it has not already been inserted in the NICU.,ECG, oxygen saturation, end-tidal CO2, and rectal（直肠） temperature should be also be monitored. A precordial stethoscope（听诊器） should be placed over the left axilla （腋窝）to assess breath sounds in case of inadvertent movement of the endotracheal tube (ETT，气管导管) during surgical retraction（手术牵拉） or positioning（体位变动）. A second precordial stethoscope placed over the stomach may be useful to assess if the fistula is being ventilated. If a gastrostomy tube（胃造瘘管） is present, the end may be placed underneath a water seal（水封瓶）.,10. What are the options regarding induction and intubation?,The goal is to intubate the baby to allow adequate gas exchange with the lowest possible inspiratory pressure needed to inflate the lungs(肺膨胀), avoid atelectasis（肺不张）, and avoid distension of the abdomen（腹部胀气）. Positive pressure mask ventilation should be avoided. There are several options. First is to keep the child spontaneously ventilating until the fistula is ligated（结扎）. Awake intubation used to be common, but attention must be paid to the possibility of increased intracranial pressure（颅内压） or intraventricular hemorrhage（室内出血） in the premature infant, as well as the obvious discomfort to the child.,Good intubating conditions can be achieved with deep volatile agent（吸入麻醉）, but maintaining adequate ventilation and surgical conditions during a thoracotomy without relaxant（肌松剂） may be challenging. Rapid sequence IV induction（诱导） and intubation (to minimize face-mask ventilation) is another option provided attention is paid to minimizing inspiratory pressure. As important as the intubation is the correct positioning of the ETT. The goal is to have the tip of the ETT distal to the fistula yet proximal to the carina（隆突）.,11. Discuss the surgical technique,First, the patient is positioned in the lateral position（侧卧位）, usually left side down. A retropleural approach（腹膜后入路） is used which minimizes the danger from an anastomotic leak（吻合口瘘）. The fistula is exposed and ligated（结扎） (usually occurs within 45 minutes). The upper esophagus is mobilized（游离）, then the distal esophagus. The esophagus is joined together. Following this, a feeding tube is placed across the anastomosis（吻合口） to allow feeding. The lung should be carefully reexpanded（再扩张） to eliminate atelectasis before closure.,12. Discuss common intraoperative problems for this repair,Interference with ventilation（肺通气） is the most common problem and can have many causes. Lung retraction with resulting atelectasis leads to frequent desaturation（低氧饱和度）. Frequent compression of vital structures in the mediastinum（纵隔） can lead to profound hemodynamic compromise（血流动力学明显波动）. Blood and secretions are a constant problem, which risk obstructing the tube.,The ETT should be suctioned（吸引） frequently, more so if blood is seen. (It does not require much blood to clog（阻塞） a 3.0 ETT.) The retracted lung may need to be intermittently reexpanded to avoid severe hypoxia（低氧）. Severe gastric distension before ligation of the TEF may require emergent gastric needle decompression（减压）. It is crucial to maintain close communication with the surgeon. Avoid hypothermia.,13. When should the baby be extubated?,Although some surgeons prefer to have the baby extubated immediately in the OR to minimize tension（张力） on the suture line（缝线）, this can be risky. Tracheomalacia（气管软化） can precipitate airway obstruction requiring immediate reintubation（再插管）. Many of the children have lung disease from prematurity or aspiration pneumonia. After receiving narcotics （麻醉性镇痛药）for pain they may be prone to hypoventilation（通气不足）. If early extubation is planned an epidural technique might be helpful. However, if the child is to remain intubated, care should be