Fibreoptic bronchoscopic positioning of double-lumen tubes

Double-lumen tubes should be placed using a fibreoptic bronchoscope. This allows correct positioning of the bronchial lumen in the chosen mainstem bronchus. It also ensures that the blue bronchial cuff does not obstruct the side to be ventilated when it is inflated under direct vision. Fibreoptic bronchoscopy facilitates correct positioning of the ventilatory side slot of a right double-lumen tube over the right upper lobe bronchus. The anaesthetist must know the fibreoptic tracheo-bronchial anatomy to properly position left- and right-sided double-lumen tubes (DLTs) and should always reconfirm the position of a DLT with fibreoptic bronchoscopy after repositioning the patient. Maintaining orientation (anterior-posterior) during fibreoptic bronchoscopy is crucial to positioning a DLT, particularly after the patient has been turned to the lateral position. A fibreoptic bronchoscope can also be used as a guide to direct a double-lumen tube under direct vision into its correct position.     

Complications of nasoenteric feeding tubes

Small-bore, silicone nasoenteric feeding tubes are increasingly utilized in the critically ill patient to provide nutritional support. The metallic-weighted tips and stiffening introducing stylets create the potential for misplacement with potentially serious consequences. We have reported our experience with 14 patients who had inadvertent tube misplacement, resulting in complications that included pneumothorax, hydrothorax, empyema, mediastinitis, pneumonia, and esophageal perforation. The incidence of radiographically detected abnormal tube position was 1.3 percent. The presence of cuffed tracheostomy or endotracheal tubes did not prevent this occurrence. The institution of enteral feedings should, therefore, be performed according to strict guidelines which include radiographic confirmation of desired position before feedings are initiated, limited and supervised use of stylets, and a need for special precautions in patients who are obtunded or receiving intubated respiratory assistance.     

Reliability of auscultation in positioning of double-lumen endobronchial tubes

Auscultation is a well-established technique to confirm the position of double-lumen endobronchial tubes (DLTs). However, some authors have recommended that fibreoptic bronchoscopy (FOB) is also indicated. The aims of this study were to determine first if bronchoscopy after blind placement of DLTs improved positioning; and second if preoperative bronchoscopy could detect difficult intubation. Twenty-four patients undergoing aortic or lung surgery were studied. After intubation with a single-lumen tube, an initial FOB was performed by an independent observer to check the airway anatomy. Then, the single-lumen tube was replaced by a DLT using a classical "blind" intubation method. Subsequent FOB was performed first by the independent observer to record the DLT position and next by the investigators for improvement or correction of their positioning under visual control. Fibreoptic bronchoscopy after blind placement of DLTs resulted in repositioning 78% left-sided DLTs and 83% right-sided DLTs. Preoperative bronchoscopy did not always detect an airway abnormality which might lead to difficult positioning of the DLTs. In conclusion, auscultation is an unreliable method of confirming the position of DLTs and should be followed by fibreoptic bronchoscopy.     

An unusual complication of naso-enteral feeding with small-diameter feeding tubes.

The occurrence of nasotracheal intubation with feeding tubes of various types is well known but poorly documented. The small-diameter feeding tubes currently available for enteral hyperalimentation may be more prone to this complication because of their small size and the rigid guide wire which is required for placement. A high index of suspicion when placing these tubes in patients at risk, use of the wire guide to pass the nasopharynx only, and x-ray verification of tube location prior to usage should avert this potentially life-threatening mistake.     

Difficulties with positioning Robertshaw double lumen tubes.

Difficulties in positioning Robertshaw tubes have been reviewed in a retrospective and a prospective series. Pre-operative cheat X-rays did not help in predicting difficulties. The performance of the Robertshaw tube was carefully recorded for each malposition in the prospective series, and the relationship of the malplaced tube to the tracheobronchial tree was reconstructed. This exercise allowed a more precise definition of the dangers of malpositions and formulation of procedure to minimize their incidence.     

Margin of safety in positioning modern double-lumen endotracheal tubes

The authors have defined the margin of safety in positioning a double-lumen tube as the length of tracheobronchial tree over which it may be moved or positioned without obstructing a conducting airway. The purpose of this study was to measure the margin of safety in positioning three modern double-lumen tubes (Mallinkrodt [Broncho-Cath], Rusch [Endobronchial tubes], and Sheridan [Broncho-Trach]). The margin of safety in positioning a: 1) left-sided double-lumen tube (all manufacturers) is the length of the left mainstem bronchus minus the length from the proximal margin of the left cuff to left lumen tip; 2) Mallinkrodt right-sided double-lumen tube is the length of the right mainstem bronchus minus the length of the right cuff; and 3) Rusch right-sided double-lumen tube is the length of the right upper lobe ventilation slot minus the diameter of the right upper lobe. The length of the right and left mainstem bronchi were measured by in vivo fiberoptic bronchoscopy (n = 69), in fresh cadavers (n = 42), and in lung casts (n = 55), and the diameter of the right upper lobe bronchus was measured in lung casts (n = 55). The average +/- SD male left and right mainstem bronchial lengths were 49 +/- 8 and 19 +/- 6 mm, respectively, the average +/- SD female left and right mainstem bronchial lengths were 44 +/- 7 and 15 +/- 5 mm, respectively, the average right upper lobe bronchial diameter was 11 mm, the proximal left cuff to left lumen tip distance was 30 mm, the length of the Mallinkrodt right cuff was 10 mm, and the length of the Rusch right upper lobe ventilation slot was 15 mm. The average margin of safety in positioning left-sided double-lumen tubes ranged 16-19 mm for the different manufacturers. The average margin of safety in positioning Mallinkrodt right-sided double-lumen tubes was 8 mm, and the margin of safety in positioning Rusch right-sided double-lumen tubes ranged 1-4 mm, depending on French size. The authors concluded that left-sided double-lumen tubes are much preferable to right-sided double-lumen tubes because they have a much greater positioning margin of safety, and that proper confirmation of proper position of either a left- or right-sided double-lumen tube should be aided by fiberoptic bronchoscopy, because the absolute distances that constitute the margin of safety are extremely small.     

Aspiration pneumonia following surgically placed feeding tubes

: The enteral route is preferred in surgical patients requiring nutritional support; however, controversy surrounds the choice of location of feeding tube placement. Although jejunostomy has been commonly accepted as superior to gastrostomy for long-term nutritional support because of an assumed lower risk of aspiration pneumonia, recent studies suggest that reevaluation of common practices of surgical tube placement is warranted. : We conducted a retrospective chart review of gastrostomy and jejunostomy procedures from 1986 to 1993. Demographic information and complications related to the procedure were reviewed. Aspiration pneumonia was defined as respiratory symptoms, leukocytosis, and infiltrate on chest radiograph. : Sixty-nine gastrostomies and 86 jejunostomies were performed during the study period. Six patients were diagnosed with aspiration pneumonia; 2 cases of which occurred with jejunostomy and 4 cases occurred with gastrostomy (P = not significant). : There was no difference in rates of pulmonary aspiration or other complications between gastrostomy and jejunostomy. We suggest that when a surgically placed feeding tube is required, the determination of appropriate procedure be based on clinical factors such as the technical difficulty of the operation or long-term feeding goals.     

Pleuropulmonary complications of fine bore naso-enteric feeding tubes

Fine bore naso-enteric feeding tubes are commonly used for enteral alimentation. Although regarded as generally safe, complications associated with their use occur. Case reports presented here highlight the potential hazards of these tubes. Pleuropulmonary complications are reviewed and guidelines suggested for the safe insertion of such tubes.     

Primary laparoscopic placement of gastrostomy buttons for feeding tubes

Background: During a 4-year period, 240 gastrostomy buttons were placed in children, as the initial surgical feeding tube, using laparoscopic techniques. Materials and methods: The technique requires the use of a minilaparoscope (1.6-mm) and a single 5-mm trocar placed at the exit site for the gastrostomy button. It can also be performed in addition to a laparoscopic fundoplication using the same trocar sites. The technique requires no special instrumentation or kits. When performed alone, operative times average 15 min. When performed with fundoplication, it adds ∼5–10 min to the time for the procedure. Results: There were no intraoperative complications and five (2.1%) postoperative complications. Conclusions: This technique has proven to be simple and effective. It allows primary placement of a gastrostomy button that is cosmetically and functionally superior to a gastrostomy tube. Received: 11 February 1999/Accepted: 27 April 1999     

Endoscopic placement of nasojejunal feeding tubes in ICU patients

Background: Enteral nutrition is an important component in the management of critically ill patients, but it may be limited by gastric ileus and unreliable positioning of standard feeding tubes. The purpose of this study was to determine the risk, utility, and outcome of endoscopically placed nasojejunal feeding tubes (NJT) in intensive care unit (ICU) patients. Methods: We reviewed the records of all ICU patients who underwent endoscopic NJT placement from May 1995 to May 1997. A through-the-scope method was used with placement of either an 8-Fr or 10-Fr 240-cm tube. Comparison was made between tubes secured to a nasopharyngeal bridle and tubes secured without bridling. Results: A total of 66 NJT were placed in 56 patients. Previous gastric feeds had been attempted in 39 patients (70%) an average of 8.4 days prior to placing the NJT. Fifty tubes (76%) were placed in the ICU and 16 (34%) in the OR at the time of additional procedures. Procedure time ranged from 7 to 28 mins (mean, 15.2), and bridling was used in 24 of 66 placements (36%). Full caloric goal rates were achieved via 56 of 66 tubes (85%) at an average of 26.1 h after placement (range, 1–144). Goal rates were not achieved in 10 cases due to inadequate tube positioning in six, ileus in three, and early dislodgement in one. A procedure complication, consisting of aspiration, occurred in one case (1.5%). Length of tube use averaged 18.5 days (range, 1–74). Accidental tube dislodgement or migration occurred in 16 of 42 (38%) nonbridled tubes vs one of 24 (4%) bridled tubes (p < .05). Conclusions: Endoscopic placement of nasojejunal feeding tubes in critically ill patients is a safe, quick, and reliable option for enteral nutrition. Full caloric goal rates can be achieved rapidly in a high percentage of patients, even in cases where previous gastric feeds have not been tolerated. Use of a nasopharyngeal bridling system for tube security significantly decreases the risk of migration or accidental tube dislodgement. Received: 15 May 1998/Accepted: 5 March 1999     

Use of transanastomotic feeding tubes during esophageal atresia repair

Purpose

Esophageal atresia (EA) with tracheoesophageal fistula (TEF) type C accounts for 85% of all EA. In our center, patients were previously started on total parenteral nutrition (TPN) postoperatively and oral feedings initiated only after a contrast esophagogram. Our aim is to assess the benefit of intraoperatively placed transanastomotic feeding tubes (TAFTs).

Methods

A 7-year retrospective review analyzed the outcomes of children with EATEF type C as they relate to the use of TAFT. Demographics, associated anomalies, operative findings, complications, duration of TPN, resumption of oral feeding, length of stay, and follow-up were examined.

Results

Twenty-one patients had EATEF type C. Eleven (55%) and 9 (45%) patients were identified as nonfeeding tube (NFT) and TAFT groups, respectively. There were no differences in gestational age, birth weight, associated anomalies, and interval to operative intervention or operative time. Excluding one patient with a severe cardiac malformation in the NFT group, there were no significant differences in anastomotic leak (8% vs 22%), stenosis (36% vs 22%), TPN duration (20 days vs 12 days), and cholestasis (36% vs 11%).

Conclusion

Transanastomotic feeding tube may lead to shorter TPN duration and decreased cholestasis, but a larger prospective study would be required to prove these benefits and ensure that it does not increase anastomotic leaks. This could be done through an expanded Canadian Pediatric Surgery Network study.