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Neonatal anaesthesia: Difference between revisions
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== GENERAL PRINCIPLES OF ANAESTHESIA IN NEONATES == | == GENERAL PRINCIPLES OF ANAESTHESIA IN NEONATES == | ||
It is important to prepare and check all equipment that may be required, prior to the start of anaesthesia (see Figure 1). | It is important to prepare and check all equipment that may be required, prior to the start of anaesthesia (see Figure 1). | ||
[[File:Figure 1 Airway an monitoring equipment.jpg|thumb|FIGURE 1. ''Airway and monitoring equipment'']] | |||
FIGURE 1 | |||
=== Monitoring === | === Monitoring === | ||
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Congenital tracheoesophageal fistula (TOF) occurs in | Congenital tracheoesophageal fistula (TOF) occurs in | ||
approximately 1:3,000 live births. It arises during foetal development as a result of incomplete separation of the oesophagus from the laryngotracheal tube. It is classified based on the site and presence of the fistula and whether there is oesophageal atresia (Figure 2). There may be other associated VACTERL anomalies. | approximately 1:3,000 live births. It arises during foetal development as a result of incomplete separation of the oesophagus from the laryngotracheal tube. It is classified based on the site and presence of the fistula and whether there is oesophageal atresia (Figure 2). There may be other associated VACTERL anomalies. | ||
[[File:Figure 2 Incidence and types of EA TEA.jpg|left|thumb|Figure 2. ''Incidence and types of oesophageal atresia/tracheo-oesophageal fistula'']] | |||
Figure 2. Incidence and types of oesophageal atresia/tracheo-oesophageal fistula | |||
Neonates with TOF classically present within a few hours of birth with frothy sputum as they are unable to swallow oral secretions; delayed diagnosis is associated with episodes of coughing and choking associated with cyanosis, particularly if feeding is attempted. There may be copious oral secretions and abdominal distension due to gastric insufflation via the fistula. Left untreated the neonate will develop aspiration pneumonia. The diagnosis of oesophageal atresia is confirmed if it is not possible to pass a nasogastric tube and the chest Xray will show the nasogastric tube coiled in the proximal blind-ending oesophagus (Figure 3). There may be an absent gastric bubble in isolated oesophageal atresia without a tracheoesophageal fistula. | Neonates with TOF classically present within a few hours of birth with frothy sputum as they are unable to swallow oral secretions; delayed diagnosis is associated with episodes of coughing and choking associated with cyanosis, particularly if feeding is attempted. There may be copious oral secretions and abdominal distension due to gastric insufflation via the fistula. Left untreated the neonate will develop aspiration pneumonia. The diagnosis of oesophageal atresia is confirmed if it is not possible to pass a nasogastric tube and the chest Xray will show the nasogastric tube coiled in the proximal blind-ending oesophagus (Figure 3). There may be an absent gastric bubble in isolated oesophageal atresia without a tracheoesophageal fistula. | ||
[[File:Figure 3 CXR NG tube in pouch.jpg|thumb|Figure 3. ''Chest Xray showing nasogastric tube curled in the upper oesophageal pouch in a child with oesophageal atresia'']] | |||
Figure 3. Chest Xray showing nasogastric tube curled in the upper oesophageal pouch in a child with oesophageal atresia | |||
The goals of pre-operative management are to stabilise the child, minimise respiratory embarrassment and assess for timing of surgery. A nasogastric tube is inserted into the upper oesophageal pouch to drain secretions. The patient | The goals of pre-operative management are to stabilise the child, minimise respiratory embarrassment and assess for timing of surgery. A nasogastric tube is inserted into the upper oesophageal pouch to drain secretions. The patient | ||
must be nursed head up or on the side to minimise the risk of aspiration. Intravenous fluids and prophylactic antibiotics should be commenced. This allows time for investigations such as an echocardiogram to exclude other associated congenital abnormalities. | must be nursed head up or on the side to minimise the risk of aspiration. Intravenous fluids and prophylactic antibiotics should be commenced. This allows time for investigations such as an echocardiogram to exclude other associated congenital abnormalities. | ||
Our preferred technique is to induce anaesthesia after pre-oxygenation and to maintain spontaneous ventilation initially with volatile or intravenous anaesthesia. Prior to repair the surgeons may perform flexible or rigid bronchoscopy to assess the level of the fistula and to see if there is a second or proximal fistula. Take note of the distance measured from the cords to the fistula to guide tracheal tube placement; the fistula is mid-tracheal in two thirds of cases, and located at level of the carina in one third of cases. Muscle relaxants and gentle mask ventilation may be given prior to intubation. If possible the tracheal tube is placed distal to the fistula, with the bevel of the tracheal tube facing anteriorly. | Our preferred technique is to induce anaesthesia after pre-oxygenation and to maintain spontaneous ventilation initially with volatile or intravenous anaesthesia. Prior to repair the surgeons may perform flexible or rigid bronchoscopy to assess the level of the fistula and to see if there is a second or proximal fistula. Take note of the distance measured from the cords to the fistula to guide tracheal tube placement; the fistula is mid-tracheal in two thirds of cases, and located at level of the carina in one third of cases. Muscle relaxants and gentle mask ventilation may be given prior to intubation. If possible the tracheal tube is placed distal to the fistula, with the bevel of the tracheal tube facing anteriorly. | ||