Correct Tube Placement Research Articles

P ARAMEDIC U SE OF E NDOTRACHEAL T UBE I NTRODUCERS FOR THE D IFFICULT A IRWAY

Objective. To evaluate the ability of paramedics to learn and apply the skill of introducer-aided oral intubation in the setting of the simulated “difficult airway.” The authors hypothesized that, following a brief introduction to the device, intubation success rates would not differ for traditional and introducer-aided intubations of an immobilized airway mannequin. Methods. During a paramedic recertification class, experienced paramedics were given a brief didactic introduction to the “bougie-like” Flex Guide endotracheal tube introducer (ETTI). The participants were then asked to intubate adult mannequins immobilized in the head-neutral position, with and without the ETTI. “Successful placement” was defined as completion of the procedure within 30 seconds and endotracheal tube position confirmed by the investigator with direct visualization. Results. For both traditional and ETTI intubations, 34 (97%) of the 35 paramedics successfully intubated within 30 seconds. The two unsuccessful intubation attempts were recognized by the paramedic as esophageal intubations, and correct tube placement was obtained within an additional 30 seconds. Conclusion. In this study, use of the ETTI was mastered by the participants after only a brief didactic introduction to the device, with their ability to intubate an immobilized mannequin using the ETTI being equal to their ability to perform traditional intubation. These results suggest that use of the ETTI is easily learned, and may support the device's role in the prehospital management of the difficult airway.

Tracheal intubation with the aid of a ‘dental mirror’

Management of the difficult airway (assessed by the Cormack–Lehane grades [1]) is a significant cause of mortality and morbidity in anaesthesia, representing the most common cause of cerebral damage or death related to anaesthesia problems (34%). Pre-anaesthetic anaesthetic evaluation may predict up to 98% of difficult intubations [2]; in these cases fibreoptics and other special techniques may be helpful and can be prepared in advance. Greater difficulties occur when difficult conventional orotracheal intubation cannot be predicted (1–3.5%) [3] or in an emergency, when fibreoptics or other special equipment and expertise may be not available. Blood and secretions may obscure the view in such cases. The ‘dental mirror technique’, which may be used in such cases; was first described by Patil [4] as an aid to tracheal intubation in a 2.5-month-old full-term infant, instead of direct laryngoscopy. Recently, Gabhash et al. [5] describe the technique as an aid to see the tube between the vocal cords and so to confirm correct or incorrect tube placement. Oesophageal intubation occurs in 5% of children and 6% of adults. The ‘dental mirror’ reduces the morbidity due to tube misplacement which may occur in 27% of predicted difficult intubations [6]. Good manual dexterity is necessary to use this device in unpredicted difficult airway situations and in emergencies where tracheal intubation is imperative. Expertise may be firstly acquired in manikins and/or cadavers, and then in patients (ASA 1–2, Cormack–Lehane grade 1–2) undergoing elective surgery. In this regard, we are carrying out a prospective study. We have studied 10 patients, three males and seven females, with a mean age of 55.1 years (range 28–72, S.D. 14.42), a mean weight of 63.5 kg (range 48–74, S.D. 8.49) and a mean height of 166.9 cm (range 154–175, S.D. 6.77). During the preoperative anaesthetic examination, nine patients were Mallampati grade I, and one Mallampati grade II. The mean interincisor gap was found of 3.89 cm (range 3.5–4.5, S.D. 0.31). The procedure was carried out by a consultant anaesthesiologist with 5 years experience. After pre-oxygenation for 3 min with the patient breathing spontaneously, anaesthesia was induced with propofol (2.5–3.5 mg/kg), fentanyl (2–4 mcg/kg), midazolam (0.05 mg/kg) and vecuronium (0.2 mg/kg). Anaesthesia was maintained by a face mask (O2/N2O/Isoflurane) for a further 2 min. Simulating a Cormack–Lehane grade 3, the anaesthesiologist then carried out a direct laryngoscopy. A mirror, previously * Corresponding author. Tel.: +39-6-22541521; fax: +39-622541444. E-mail address: f.agro@unicampus.it (F. Agro)

Capnography-Guided Nasotracheal Intubation of a Patient with a Difficult Airway and Unwanted Respiratory Depression

Capnography-Guided Nasotracheal Intubation of a Patient with a Difficult Airway and Unwanted Respiratory Depression

Complications with non-endoscopic percutaneous gastrostomy in 31 cats and 10 dogs: a retrospective study.

Percutaneous gastrostomy tubes were placed non-endoscopically in 31 cats and 10 dogs using either a rigid insertion tube (n = 13) or an Eld gastrostomy tube applicator (n = 28). Tubes were placed successfully in 38 of the 41 animals and the consequent feeding was of therapeutic benefit to 31 of the animals. Six of 41 died or were euthanased for reasons unrelated to gastrostomy. In four cases (10 per cent), gastrostomy failed with respect to correct tube placement or tube feeding. Overall complications occurred in 18 of 41 animals. Severe procedural complications occurred in two cats; a cardiorespiratory arrest during pharyngeal manipulation and erroneous tube placement through the distal oesophagus. Moderate late complications included peristomal food leakage (n = 2), peristomal abscess (n = 2) and pyloric outflow obstruction by a migrated tube (n = 1). Complications associated with the feeding procedure, nausea and vomiting (n = 3), led to aspiration pneumonia in one case.

Video Review

Video Review

The use of bromothymol blue and sodium thiopentone to confirm tracheal intubation

The possibility of using chemical changes to confirm correct tracheal tube placement was investigated with a view to their use in developing countries where more sophisticated methods are unavailable. The effect of bubbling expired gases through a 10% solution of bromothymol blue and a 0.25% solution of thiopentone led to chemical changes producing, in the case of bromothymol blue, a colour change and in that of thiopentone, precipitation, probably due to a change in pH caused by carbon dioxide. We also discovered that the time to precipitation of the thiopentone could be greatly reduced if it was mixed with a precise quantity of lignocaine. These simple end points can reliably confirm the correct placement of a tracheal tube at least as rapidly as the correct use of capnography.

Correct tracheal tube placement

Correct tracheal tube placement

Difficult and impossible intubation

This chapter reviews the problem of the management of the difficult airway. Although the incidence of difficulty is relatively small, the consequences of mismanagement can be quite disastrous. Prediction of the difficult intubation can be made by a variety of simple clinical observations and measurements in a majority of cases. A combination of these methods is likely to lead to a lower index of false positives. Radiological assessment may be valuable if planned beforehand. Nevertheless, a number of cases of unsuspected difficulty occur. The options available in cases of difficulty are reviewed, including direct laryngoscopy using the oral and nasal routes, fibreoptic guided intubation and the use of special guiding laryngoscope blades and ancillary devices such as the laryngeal mask, the pharyngotracheal lumen airway, the Combi tube and the light wand. The technique of retrograde guided intubation is described. The surgical airway is required in certain cases of impossible intubation. Cricothyrotomy is the technique of choice in the emergency situation because it is simpler and safer to perform. Tracheostomy may be preferred in the planned case with an anticipated long-term problem. Confirmation of correct tracheal tube placement is essential. Unrecognized misplacement leads to death or severe brain damage. Simple clinical methods are generally satisfactory but are not infallible. Other methods of confirmation such as fibreoptic visualization, light wand transillumination, carbon dioxide detectors and air aspiration are discussed. A regimen for difficult airway management is produced as an algorithm.

Endotracheal intubation skills of medical students.

The ability and confidence of clinical medical students to insert endotracheal tubes correctly and quickly and to recognize oesophageal misplacement was evaluated. Ten (33%) of the medical students intubated the trachea correctly at their first attempt but 14 (47%) incorrectly identified the position of the endotracheal tube. However, recognition improved by their second and third attempts (70% and 80% respectively). Ninety-three percent of students intubated correctly on their third attempt. Although medical students can obtain better results at correct tube placement with repeated attempts under optimum conditions--a practice effect--and do better at recognizing correct tube placement there is still a persistent failure to recognize endotracheal tube misplacement, ie oesophageal intubation. It is the ability to recognize oesophageal intubation promptly that is a life-saving skill. This essential skill should be taught during the introductory anaesthesia programme through the use of clinical patients.

A clinical evaluation of the ‘Rapitrach’

A number of percutaneous tracheostomy devices are now available commercially. We report a preliminary clinical study of the use of the 'Rapitrach' kit (Fresenius, Runcorn, Cheshire, UK). Twenty critically ill adult patients underwent tracheostomy using the kit. Nineteen of the procedures were carried out at the bedside in the intensive therapy unit. Correct tube placement was achieved in all cases.

Intubation guide marks for correct tube placement A clinical study

The tracheas of 140 adult patients were intubated with either TFX or Portex tracheal tubes. Guide marks were printed at variable distances proximal to the tube cuffs, and during intubation the guide mark was positioned at the level of the vocal cords. The distance between the bevel end of the tube and the carina was determined with a fibreoptic bronchoscope. The mean distance between the tip of the tracheal tube and the carina varied between 3.7 and 4.1 cm with the head in the neutral position. The tip of the tracheal tube approaches the carina by a mean distance of 0.5 cm when the head is moved from the extended position to the neutral position. It is recommended that a guide mark be placed 2.5 cm from the proximal end of the cuff in tubes used for adult males and 2.25 cm in tubes used for adult females. The use of guide marks is a simple, safe and reliable method for correct tracheal tube placement.

Pulse Oximetry in Confirmation of Correct Tracheal Tube Placement

Department of Anesthesiology Rush-Presbyterian-St. Luke's Medical Center 1653 West Congress Parkway Chicago, IL 60612

Enteral Nutrition: Potential Complications and Patient Monitoring

Enteral feedings are safely tolerated by most patients. When complications occur, gastrointestinal disturbances are most frequently encountered, followed by mechanical and metabolic complications. Nurses can prevent many of the problems associated with enteral feeding through careful monitoring. Based on the current literature, the authors make the following recommendations: 1. All patients receiving tube feedings should be placed on a protocol that provides guidelines for (a) confirming correct tube placement; (b) preventing/managing tube obstruction; (c) handling and selecting formulas; (d) administering formulas; and (e) monitoring patients. 2. Fine-bore tubes are easily misplaced or dislodged; ensure correct positioning both before and during feeding. Food coloring should be added to all feedings to help detect aspiration/tube displacement. 3. Multiple factors can cause diarrhea in tube-fed patients and, therefore, require periodic assessment. These factors include concomitant drug therapy; malnutrition/hypoalbuminemia; formula-related factors (for example, lactose content, osmolality); and bacterial contamination. 4. Urine sugar and acetone levels should be checked every 6 hours (until stable). Vital signs and fluid intake and output should be determined every 8 hours, and weight should be measured on a daily basis. Serum electrolytes, blood urea nitrogen, and glucose levels should be determined daily, until serum levels stabilize. Weekly measurements of trace elements should be made to ensure adequate mineral replacement. 5. Use a controller pump to administer continuous feedings at a constant rate or to administer formulas that are viscous. Flush feeding tubes with water every 4 hours during continuous feedings, after giving intermittent feedings, after giving medications, and after checking for gastric residuals. If tube obstruction occurs, attempt to irrigate the tube with either water or cola. 6. Select feedings that contain appropriate nutrient sources, caloric density, and osmolality; handle feedings in a way that minimizes bacterial contamination.

Confirming tracheal intubation - a simple manoeuvre.

A simple technique is described for confirming oral tracheal intubation carried out under direct laryngoscopy. With the laryngoscope blade still in the mouth following intubation, posterior displacement of the tracheal tube towards the palate will usually bring the tube and vocal cords into direct view, providing confirmation of correct tube placement. In 50 consecutive oral tracheal intubations, the tube was seen to pass between the vocal cords in 29 cases, confirming correct tube placement. In the remaining 21 cases, the larynx was obscured during intubation. Posterior displacement of the tube confirmed correct placement in all 21 cases.