a) Before induction, the neonate’s stomach must be emptied via orogastric tube. Some anesthesia providers irrigate the stomach via the orogastric tube with warm normal saline until the aspirate is clear and minimal. Others tilt the baby in various directions to evacuate the remaining contents.

b) After preoxygenation, the induction should be a modified rapid sequence with properly applied cricoid pressure and gentle positive-pressure ventilation via mask. (Many practitioners still perform an awake oral or a true rapid sequence.)

c) Oral endotracheal intubation is mandated to protect the airway from any gastric contents that may be residual.

d) Maintenance can be with inhalation anesthetics or in combination with intravenous (IV) drugs.

e) These babies should be extubated awake.

f) Postoperatively these patients, particularly a preterm or SGA neonate, could exhibit drowsiness, lethargy, or apnea. This could be attributed to electrolyte abnormalities or postconceptual age.

a) Because of the many possible patient issues, the anesthetic technique must be tailored for each patient.

b) Inhalation or IV induction is acceptable as well as airway management with a mask, laryngeal mask airway, or endotracheal tube (ETT).

c) The use of the laparoscopic approach necessitates the use of an ETT.

d) Maintenance can be with inhalation anesthetics or in combination with IV drugs.

e) Small neonates who are at risk for postoperative apnea and bradycardia may benefit from spinal anesthesia.

a) A thorough assessment of the baby, including laboratory, radiographic, and physical symptoms, is mandatory.

b) Listening to breath sounds will assist in evaluating the degree of ventilation on each side of the chest after intubation.

c) Because of the respiratory manifestations of the problem, the patient will be already intubated and have IV access and arterial lines in place when arriving in the operating room.

d) If the patient is not intubated, an ETT should be placed after a rapid-sequence induction. If a difficult airway is suspected, an awake intubation should be done.

e) It is important in these patients to administer an anticholinergic (atropine 0.02 mg/kg) IV just before induction to prevent the bradycardia during induction.

f) If an awake intubation is planned, some type of analgesia should be used to decrease the stress response of airway instrumentation.

g) Ventilation should be delivered gently to avoid inflating the stomach with air, further compromising the pressure in the chest. Volutrauma can be avoided by delivering small tidal volume and PEEP if necessary.

h) The patient’s hemodynamic stability should determine the anesthetic drugs used. A high-dose narcotic technique is commonly used (fentanyl, 15-25 mcg/kg) if tolerated.

i) The use of inhalation agents must be judicious because they pose significant risk to the baby’s cardiovascular stability.

j) Nitrous oxide should be avoided because it will increase the volume of gastrointestinal tissue and further impair ventilation.

k) Monitoring must include blood pressure, ECG, pulse oximetry, capnography, temperature, and heart rate.

l) To monitor for right-to-left cardiac shunting, oximeter probes should be placed preductal (right upper extremity) and postductal (lower extremity).

m) The use of arterial blood pressure monitoring not only allows beat-to-beat assessment of blood pressure but also provides an outlet for easier blood sampling.

n) All conditions that can increase pulmonary vascular resistance (hypoxia, hypothermia, or acidosis) should be avoided.

o) Carbon dioxide should be kept at normal or slightly elevated levels, and oxygen saturation should be maintained above 80 mmHg.

p) Any derangement of electrolytes should be corrected quickly, and any significant blood loss should be replaced.

q) In the event that cardiorespiratory instability prevents the neonate from being transported to the operating room, the anesthesia provider might be required to administer anesthesia in the NICU while the baby is still on ECMO.

r) Under these circumstances, the recommended anesthetic choice is an opioid and nondepolarizing muscle relaxant technique instead of an inhalation agent.

s) Postoperative ventilation is required with the goal of keeping the arterial oxygenation greater than 150 mmHg and slowing weaning to lower oxygen concentrations over a 48- to 72-hour period.

a) A newborn with an omphalocele or gastroschisis is usually brought to the operating room very soon after birth to minimize the possibility of infection, the loss of fluid and heat, and the possible death of bowel tissue.

b) A thorough preoperative evaluation must be done to identify the presence of any of the previously mentioned associated anomalies.

c) Historically, the surgical approach was to immediately attempt primary closure of the defect. This entailed placing a large amount of abdominal contents into a cavity that was not usually large enough, and the result was a significant increase in intraabdominal pressure that impeded ventilation and profound hypotension secondary to aortocaval compression.

d) Over the past decade, surgeons have opted for a staged closure using a Silastic silo as a temporary housing for the bowel. This silo is sutured to the defect, and the silo is reduced over the next 3 to 7 days to allow for accommodation of the gastric contents and abdominal wall stretching. Then the neonate is usually brought for complete closure.

e) In the event primary closure is attempted, it should be noted that excessive intraabdominal pressure can increase the possibility of unsuccessful completion of the closure, as shown in the following box.

f) The choice of anesthetic agent and technique is determined by several guiding principles: severe dehydration and massive fluid loss from exposed viscera and internal third spacing of fluid caused by bowel obstruction, hypothermia, the potential for sepsis and associated anomalies, and postoperative ventilation requirements.

g) It is common for the anesthesia provider to choose an opioid and nondepolarizing muscle relaxant technique; however, the abdominal wall may not allow primary closure even with the use of muscle relaxants.

h) Ventilatory compromise and decreased organ perfusion are major problems as intraabdominal pressure increases.

i) Adequate IV access is essential to infuse large amounts of fluid quickly and invasive monitoring guides the replacement.

j) A pulse oximeter probe on a lower extremity will indicate if there is compromise in the perfusion to the lower extremities caused by obstruction of venous return.

k) Postoperative ventilation will be mandatory on all of these babies requiring the continued use of paralytics and sedation with an opioid until their clinical status stabilizes.

a) There is a significant association of other serious congenital anomalies in these babies. Some sources report as high as 30% to 50% of newborns with EA and TEF have other anomalies, particularly VACTERL (vertebral anomalies, anal atresia, cardiac defects, TEF, renal abnormalities, and limb malformations) association.

b) EA with a distal fistula is the most common presentation of TEF in approximately 80% to 90% of patients.

c) The esophagus ends in a blind pouch, and the distal esophagus forms a fistula with the trachea, usually above the carina.

d) There are five other configurations of this anomaly, varied by the location of the fistula and the presence or absence of EA.

e) The morbidity and mortality of TEF are directly related to the resulting pulmonary complications from aspiration of feedings.

a) The focus of the preoperative preparation should be to minimize the pulmonary complications by discontinuing oral feedings, placement of a tube to suction nasopharyngeal secretions that accumulate in the blind esophageal pouch, maintain the infant in a semirecumbent position to minimize aspiration of secretions, and placement of a gastrostomy tube to prevent excess gastric distention from impairing ventilation, and to take measures to prevent dehydration.

b) The surgical procedure is performed via a thoracotomy incision, usually on the right side. The sequence of the repair is the ligation of the fistula and then anastomosis of the two ends of the esophagus, if possible.

c) Standard monitors should be used. The precordial stethoscope should be placed in the left axilla after induction to allow for monitoring of ventilation and heart sounds.

d) The cardiorespiratory condition of the neonate should dictate the use of more invasive monitoring techniques such as an arterial line (umbilical or radial). In the youngest critically ill patients, preductal and postductal oximeter probes may be used.

e) The technique of induction should be based on the clinician’s evaluation of the airway. When there is concern of a difficult airway, an “awake intubation” should be performed. This technique minimizes the gastric distention from anesthetic gases passing through the fistula and allows proper placement of the ETT without positive-pressure ventilation.

f) When airway management is determined to be “routine,” an inhalation induction with gentle positive-pressure ventilation and intubation can be used.

g) To further minimize stomach distention, spontaneous ventilation to an adequate depth of anesthesia followed by endotracheal intubation may be carried out.

h) If this technique is used, care must be taken to avoid hypoxemia that will result from the respiratory depression produced by high concentrations of inhalation agents.

i) Another accepted technique is the IV rapid-sequence induction with endotracheal intubation.

j) With any of the above-mentioned techniques, proper position must be verified after the ETT is placed. A common method of verifying the correct position is to actually intubate the right mainstem bronchus and then withdraw the ETT until breath sounds are heard on the left side of the chest. The tip of the tube is likely between the fistula and the carina.

k) If there is a gastrostomy in place, another method is to submerge the gastrostomy tube in water and, if there are bubbles on ventilation, the fistula is being ventilated and the tube must be repositioned.

l) The bevel of the ETT should be turned anteriorly to allow the posterior surface of the ETT to occlude the fistula.

m) In one configuration of TEF, the fistula is located very close to the carina. In this case, the ETT may need to be placed in the bronchus of the nonoperative lung until the fistula can be ligated. After ligation, the tube can be withdrawn to above the carina.

n) During the procedure, it is essential to monitor ventilation very carefully. Airway obstruction can occur if the trachea is compressed or if secretions or blood block the openings of the ETT. This must be corrected immediately.

o) The neonate without significant pulmonary complications, who is awake and moving vigorously, is most often extubated in the operating room.

p) Blood and secretions may be present in the ETT and should be suctioned gently before removal.

q) If there is any concern about airway obstruction or impaired ventilation, mechanical ventilation should be continued.

r) It is thought that if bag and mask ventilation or reintubation is required, undue stress could be placed on the suture lines of the repair with laryngoscopy and neck extension, resulting in damage to the esophagus and necessitating further surgical procedures.

s) Another problem that can occur with early extubation in smaller neonates is an inability to maintain the work of breathing because of preoperative lung disease.

t) If postoperative mechanical ventilation is needed, the ETT should be positioned 1 cm away from the fistula repair to allow for healing of the suture line.

u) A suction catheter should be clearly marked with a distance for insertion that approximates the distance just above the anastomotic repair.

v) Postoperative pain can be managed with opioids or a caudal epidural (or both) placed intraoperatively.

a) Complications may occur later that could influence anesthetic management.

b) Neonates who have had EA or TEF repair early in life can develop a diverticulum at the site of the old tracheal fistula. This could present problems in the future if inadvertent intubation of the diverticulum occurs.

c) Esophageal stricture could develop at the site of esophageal anastomosis, requiring repeated dilation or possible resection.

a) The major concerns in anesthetic management are airway management, fluid and electrolyte replacement, treatment of sepsis, and postoperative pain management.

b) Any baby with intestinal obstruction will likely have abdominal distention, which could impede diaphragmatic movement, and is at higher risk for aspiration of gastric or intestinal contents.

c) This necessitates the use of a rapid-sequence induction with the proper application of cricoid pressure.

d) If there is concern for a difficult airway, then awake intubation should be considered.

e) There is likely volume depletion caused by peritonitis, ileus, bowel manipulation, and sepsis. It is absolutely necessary to have adequate IV access, and it is desirable to have a central line and an arterial line.

f) The choice of anesthetic agents should depend on the neonate’s condition. It is not advisable to use nitrous oxide, but other inhalation agents are acceptable.

g) As with other emergent abdominal procedures, postoperative mechanical ventilation may be required, making the intraoperative choice of an opioid and nondepolarizing muscle relaxant a good choice.

h) Although anesthetic agent choice is not critical, the maintenance of an adequate circulating volume and red blood cells is vital to ensure perfusion of vital organs.

a) Diagnosis is confirmed by abdominal radiography that shows fixed dilated intestinal loops, pneumatosis intestinalis, portal vein air, ascites, and pneumoperitoneum.

b) Accompanying laboratory values might show evidence of hyperkalemia, hyponatremia, metabolic acidosis, hyperglycemia, or hypoglycemia and, in the most serious cases, signs of disseminated intravascular coagulation.

c) The common symptoms of NEC are listed in the following box.

d) When an attempt at medical management is unsuccessful, surgical intervention consists of an exploratory laparotomy with resection of dead bowel, usually a colostomy, and peritoneal lavage.

a) These neonates are very sick and usually come to the operating room already intubated and with ventilator support.

b) If they are not intubated, a rapid-sequence induction or awake intubation is indicated.

c) The anesthetic drugs chosen should depend on the patient’s condition, but a common choice is a narcotic and relaxant technique. These are thought to be the safest choice in the presence of cardiovascular instability because the inhalation agents may further depress the myocardium and lower the blood pressure to unacceptable levels.

d) Nitrous oxide is avoided, and compressed air can be added to the gas mixture if there is concern over high oxygen concentrations.

e) If cardiac output is low and renal perfusion is below normal, dopamine may be indicated.

f) The amount of third space loss in these patients is very large and may require multiple blood volumes of crystalloid and colloid combinations to replace intravascular volume. Red blood cells, fresh-frozen plasma, and platelets also may be required to increase oxygen-carrying capacity or to treat factor deficiency.

g) The postoperative care should focus on continuation of the fluid resuscitation and cardiorespiratory support and mechanical ventilation until the baby stabilizes.

a) In male newborns, the operative procedure may be urgent to allow the passage of meconium via a colostomy.

b) In female newborns, because of the usual presence of a rectovaginal fistula, the procedure can be delayed for a few weeks.

c) The anesthetic considerations for the neonate are based on the existence of associated anomalies and fluid and electrolyte balance.

1. Introduction

    Hydrocephalus is usually the result of some existing pathologic process. It is usually caused by an obstruction in the CSF system or an inability to absorb CSF. The standard treatment is the placement of a shunting catheter from the ventricle of the brain to another location to allow absorption of the fluid. Most often the shunt is placed from the cerebral ventricle to the peritoneal cavity. Occasionally, the catheter will be placed in the right atrium or pleural cavity. In newborns and neonates, if the hydrocephalus develops slowly, the cranial vault will expand to accommodate the increase in brain bulk. When there is no more ability to expand, ICP begins to increase, and the baby will start to exhibit signs and symptoms of increased ICP.

2. Clinical manifestations

    The signs and symptoms of increasing ICP are a tense anterior fontanel, irritability, somnolence, or vomiting.

3. Anesthetic technique

1. Introduction

    Myelomeningocele is the most common CNS defect that occurs during the first month of gestation. Another common name for this defect is spina bifida. It is failure of the neural tube to close, resulting in herniation of the spinal cord and meninges through a defect in the spinal column and back. If the herniation only contains meninges, it is a meningocele. If the herniation contains meninges and neural elements, it is a myelomeningocele. These lesions mostly occur in the lumbosacral region but can occur at any level of the neuraxis. The repair of the defect is considered urgent and is usually undertaken within the first 24 hours of life to avoid the increasing risk of bacterial contamination of the spinal cord and further deterioration of neural and motor function.

2. Clinical manifestations

3. Anesthetic technique