Improved design of nasogastric feeding tubes

Disappointed with the overall performance of weighted and unweighted nasogastric feeding tubes, a design programme was initiated which resulted in the development of two new nasogastric tubes, one weighted and one unweighted. The tubes were manufactured with polyurethane rather than polyvinylchloride (PVC) which permitted an increase in diameter of the internal lumen which in turn was coated with water activated lubricant to ease removal of the introducer wire. A specially modelled outflow port was incorporated into the tips of both tubes. The performance of the two new polyurethane nasogastric feeding tubes was assessed under controlled trial condition using as a reference a widely used PVC unweighted open ended tube. While intubation times were similar in patients without concurrent endotracheal intubation, it took a significantly shorter time to intubate patients with concurrent endotracheal intubation with the new weighted tube. Following tube intubation, it was possible to aspirate gastric contents significantly more often through the new polyurethane tubes (p < 0.001) than through the PVC tube, and the unweighted polyurethane tube stayed in situ longer (p < 0.05) than the PVC tube. The newly designed polyurethane nasogastric feeding tubes are the first tubes that have been shown to have advantages over the simpler type of open ended, unweighted PVC nasogastric feeding tubes.     

Lung perforation by nasogastric feeding tubes

Endotracheal misdirection of narrow bore nasogastric feeding tubes resulted in perforation of the lung, pneumothorax and hydrothorax in two intensive care patients. Both were intubated with cuffed endotracheal low pressure tubes, one patient was on respirator therapy with neuromuscular relaxation. Feeding tubes were inserted by experienced personnel with the assistance of a steel stylet without difficulties. Aspiration of fluid was misinterpreted as proof of correct positioning, the liquid being however pleural effusion and not gastric juice. Similarly auscultation of gurgling sounds in the upper epigastrium was not a reliable sign of intragastric position. Insertion of nasoenteric feeding tubes may be complicated by perforation of the upper gastrointestinal tract and lung in poorly responsive patients with cuffed endotracheal devices during neuromuscular blockage. In these patients a laryngoscope and forceps should be used to ensure free passage of the tube into the oesophagus. R?ntgenographic confirmation of correct positioning of the tube immediately after insertion is mandatory.     

超滑涂层气管导管用于全麻下非困难气道气管插管的临床效果

目的:与普通气管导管相比,观察超滑涂层气管导管是否减轻全麻插管刺激及改善操作效果。方法:选取2016年7月~2017年1月全麻插管的患者60例,ASA分级Ⅰ~Ⅱ级,患者随机分为超滑气管导管组(观察组)和普通气管导管组(对照组)。记录插管时间和插管阻力评价;记录诱导前(T0)、插管前(T1)、插管即刻(T2)、插管后1min(T3)、3min(T4)、5min(T5)、术毕自主呼吸恢复(T6)SBP、DBP、MAP和HR;记录拔管后和术后24h出现咽痛的情况。结果:两组患者T2、T3、T6时对照组SBP、DBP和MAP明显高于观察组(P<0.01),T2、T3、T4时对照组HR明显高于观察组(P<0.01),观察组插管时间短于对照组(P<0.05),对照组术后咽痛发生高于观察组(P<0.05)。结论:超滑气管导管在非困难气道使用时有益于患者血流动力学平稳,缩短插管时间,有效降低术后咽痛的发生率,是一种安全有效的气管插管工具。     

Endoscopic placement of fine bore nasogastric and nasoenteric feeding tubes

In a small proportion of patients requiring enteral nutrition it may not be possible to site nasogastric or nasoenteric feeding tubes using standard intubation techniques. We describe an endoscopic method of tube placement applicable not only for positioning nasogastric feeding tubes in patients with coexisting oesophageal pathology, but also for placement of nasoenteric feeding tubes when disordered gastric emptying is present.     

气管导管位置检测仪的研制

利用Hall传感器设计了一个气管导管位置检测仪来快速检测气管导管的位置.气管插管时,Hall传感器探头固定在病人颈部皮肤上,顶端带有小磁铁的管芯随气管导管一起进入气管中,根据检测到的磁场强度的大小,测量出探头与磁铁间的距离,从而判断出气管导管的位置.经临床测试,该检测仪性能可靠,测量准确,可以用于教学及临床气管插管时气管导管的定位.     

Clinical audit: optimal positioning of endotracheal tubes in neonates

BACKGROUND: The malposition of endotracheal tubes (ETTs) can be associated with endo-bronchial intubation or accidental extubation. A variety of methods have been reported for predicting insertional length (IL) including weight, nasal-tragus length (NTL) and sternal length (STL) measurements. In our unit no consistent predictor method was being used. AIM: To audit the proportion of endotracheal tubes that required a significant position change after oral intubation. Our standard set was that the endotracheal tube should be in a satisfactory position in > 80% of cases. If not met, practice would then be re-audited after a consistent predictor method had been implemented. METHODS: Data regarding changes in endotracheal tube position were collected. Significant position changes were defined as adjustments > 0.5 cm. RESULTS: Twenty two babies were included in the initial audit, and only 73% of endotracheal tubes had a satisfactory position. Thirty six babies were included in the re-audit and when the nasal-tragus length predictor was used, 94% of endotracheal tubes had a satisfactory position, meeting the standard. CONCLUSION: The nasal-tragus length predictor improved the accuracy of endotracheal tube positioning after oral intubation. It is a simple, fast, reproducible method and can be used in everyday practice to help avoid significant endotracheal tube malposition.     

Do nasogastric feeding tubes cause gastro-oesophageal reflux in healthy subjects?

The potential relationship between nasogastric intubation and acid gastro-oesophageal reflux was investigated. Ten healthy volunteers underwent 24h oesophageal pH monitoring following intubation with (i) a pH monitor alone, (ii) a pH monitor plus a Ryles nasogastric tube and (iii) a pH monitor plus a fine-bore nasogastric feeding tube. Neither of the nasogastric intubations were associated with significant reflux.     

Clinical evaluation of a newly designed nasogastric enteral feeding tube

Concerned with reports in the literature of a rising incidence of enteral feeding tube clogging, we initiated a design programme in an attempt to improve the clinical efficacy of nasogastric and nasoenteric enteral feeding tubes. Tube design has been based on a remodelling of the outflow part of a polyurethane feeding tube previously developed in our unit. The tip of the newly designed 8F enteral feeding tube is shorter in length with a rounded end to minimize discomfort during intubation. The port itself incorporates a tapered outflow design with the side walls now extending below the mid-point of the internal flow lumen resulting in a 28% increase in port area compared to the equivalent and originally designed tube. The performance of the newly designed polyurethane feeding tube was assessed under controlled trial conditions using as references two widely used 8F polyurethane nasogastric feeding tubes whose design has been based on different principles (Flexiflo, weighted tip, open-ended with two side ports; Freka, occluded tip, two simple large side ports). Eighty-eight of 90 patients entered into the study were successfully intubated with no significant differences being noted in intubation times in the three groups. Significantly less discomfort occurred during intubation of patients with the Radius tube as compared to the Freka tube (P < 0.05). Although there were no clear differences between the Flexiflo and Freka tubes either in regard to the number of attempts required for intubation or aspiration or discomfort during intubation or ease of aspiration, fewer attempts at insertion and aspiration were needed and intubation and aspiration were easier for patients randomised to the Radius group than those to the Flexiflo and Freka groups (P < 0.05). We conclude that the clinical performance of the newly designed Radius enteral feeding tube compares favourably with that of the reference tubes. Only one of the new tubes (3.3%) blocked during the course of the study. High rates of non-elective extubation were observed in the three study groups (Radius 80.0%, Flexiflo 73.3%, Freka 73.3%). Design modifications are unlikely to influence non-elective nasogastric feeding tube extubation rates which remain a major clinical problem.     

Determination of a practical pH cutoff level for reliable confirmation of nasogastric tube placement

Background: Enteral feeding is a common method of nutrition support when oral intake is inadequate. Confirmation of correct nasogastric (NG) tube placement is essential. Risks of morbidity/mortality associated with misplacement in the lung are well documented. Studies indicate that pH ≤4 confirms gastric aspirate, but in pediatrics, a pH of gastric aspirate is often >4. The goal of this study was to determine a reliable and practical pH value to confirm NG tube placement, without increasing the risk of not identifying a misplaced NG tube. Methods: Pediatric inpatients older than 4 weeks receiving enteral nutrition (nasogastric or gastrostomy) were recruited over 9 months. Aspirate samples were pH tested at NG tube placement and before feedings. If pH >4, NG tube position was confirmed by chest radiograph or further investigations. In addition, intensive care unit (ICU) patients who required endotracheal suctioning were recruited, and endotracheal aspirate samples were pH tested. Results: A total of 4,330 gastric aspirate samples (96% nasogastric) were collected from 645 patients with a median (interquartile range [IQR]) age of 1.0 years (0.3–5.2 years). The mean (standard deviation [SD]) pH of these gastric samples was 3.6 (1.4) (range, 0–9). pH was >4 in 1,339 (30.9%) gastric aspirate samples, and of these, 244 were radiographed, which identified 10 misplaced tubes (1 with pH 5.5). A total of 65 endotracheal aspirate samples were collected from 19 ICU patients with a median (IQR) age of 0.6 years (0.4–5.2 years). The mean (SD) pH of these samples was 8.4 (0.8) (range, 6–9.5). Conclusion: Given that the lowest pH value of endotracheal aspirate sample was 6, and a misplaced NG tube was identified with pH 5.5, it is proposed that a gastric aspirate pH ≤5 is a safer, reliable, and practical cutoff in this population.     

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.     

气管导管引导胃管置入的临床应用及护理

留置胃管是ICU最常见的基础护理操作,但由于受各种因素的影响,临床中置管困难的现象时有发生。本文介绍了使用气管导管引导胃管置入的方法为3例咽喉部水肿的危重病人留置胃管,一次置管成功,早期为病人提供肠道营养,促进病人康复。     

气管导管引导胃管置入的临床应用及护理

留置胃管是ICU最常见的基础护理操作,但由于受各种因素的影响,临床中置管困难的现象时有发生。本文介绍了使用气管导管引导胃管置入的方法为3例咽喉部水肿的危重病人留置胃管,一次置管成功,早期为病人提供肠道营养,促进病人康复。     

异型气管导管、钢丝气管导管及普通气管导管在五官科手术中的应用比较

目的评价3种气管导管在五官科手术中的安全性及实用性。方法择期五官科手术63例,随机分为3组,异型气管导管组（A组,n=25）;钢丝气管导管组（B组,n=17）;普通气管导管组（C组,n=21）。观察插管前后及术中病人的MBP、HR、SpO2。结果三组之间插管前后比较无明显差异,术中B组出现2例因导管滑入主支气管引起SpO2下降;C组出现1例因导管打折致SpO2急剧下降,需紧急更换异型气管导管。结论与普通气管导管和带钢丝气管导管相比,异型气管导管具有特定的弯曲度,容易固定且价格低廉,在五官科手术中的应用比较完全、实用。     

Pleural complications of nasoenteric feeding tubes

Pliable, small-bore, feeding tubes are inserted frequently in critically ill patients. The use of wire stylets to facilitate passage of these tubes has increased the chances of unrecognized tracheal intubations, particularly in obtunded patients. Five patients with depressed sensoria had inadvertent transbronchial insertions of feeding tubes into their pleural spaces over a 28-month period. The incidence of this complication among intensive care unit patients was 0.3%. Sequellae included pneumothoraces in four patients, pleural effusions in three patients, and pneumonia with a pulmonary abscess in one patient. The presence of cuffed endotracheal tubes did not prevent this complication in patients with depressed cough reflexes. Inexperience of feeding tube insertors may have contributed to pleural intubations in four of the patients. In patients with depressed sensoria, adequate confirmation of feeding tube location in the stomach or duodenum requires both chest and abdominal roentgenograms.     

Nasopulmonary intubation with feeding tubes: case reports and review of the literature

Pulmonary aspiration of regurgitated feeding material is a recognized complication of enteral nutrition by feeding tube. Nasopulmonary intubation with feeding tubes has been reported infrequently. We present two patients with such complications. In one, nasopulmonary intubation resulted in a pneumothorax. In the other unrecognized misplacement resulted in pneumonia and hydrothorax. Similar cases in the literature are discussed. Common features of this complication are: (1) patients who are obtunded, debilitated, or without gag reflex; (2) previous successful insertion of a tube; (3) successful passage past endotracheal tubes and tracheostomies; and (4) positive auscultation of insufflated air over the left upper quadrant. Complete prevention of this complication probably is not possible, but health care personnel should be aware of this potential problem in the patient at risk.     

Improving learning of a clinical skill: the first year's experience of teaching endotracheal intubation in a clinical simulation facility

BACKGROUND: All medical practitioners should be able to manage the airway of an unconscious patient. Endotracheal intubation is the most effective method of securing the airway but is a complex skill requiring much practice. Traditionally, endotracheal intubation has been taught on patients, but this is not ideal. METHODS: We have developed a short course on endotracheal intubation taught in a clinical simulation unit (CSU). This unit has a large range of airway trainers and patient simulators, some of which can be manipulated to make intubation more difficult. Endotracheal intubation is taught in a series of steps in order to avoid cognitive overload. Each step is taught on an airway trainer that has no difficult features. Once this is mastered, more difficult situations are presented which require application of new techniques and/or equipment. In this way, students learn useful schemas to apply clinically. RESULTS: In 1 year, over 100 students and trainees were taught endotracheal intubation in the CSU. The ideal group size was found to be two students and one trainer. It took 75 to 90 minutes for most students to reach a standard where they could be expected to safely perform the technique on a patient. All comments on learning endotracheal intubation in this setting were positive. Many students felt more comfortable learning on a model than on a patient. CONCLUSION: Learning clinical procedures on simulators is becoming an essential part of medical education. More than one airway trainer may be needed to give students the expertise to perform endotracheal intubation on patients.     

Endotracheal An?sthesia

(1) With certain exceptions, endotracheal anæsthesia is the best method for operations on the head and neck and for any other operation in which there may be a difficulty in controlling the patient''s air-way. (2) Expiration should be provided for, in endotracheal anæsthesia, either by means of a second tube or by a tube of calibre sufficient to permit to-and-fro respiration. (3) Cocainization of the upper air-passages has decided advantages in endotracheal anæsthesia. (4) “Blind” intubation through the nose renders the method possible in cases where it is impossible to use a speculum. (5) The insufflation method is not specially indicated in abdominal surgery. (6) The routine use of endotracheal anæsthesia in teaching-hospitals for every class of case is detrimental to the production of sound anæsthetic knowledge in students who are likely to become general practitioners.     

Clinical indications for weighted enteral feeding tubes

Simple unweighted fine bore feeding tubes have been used by our Nutritional Support Team for routine nasogastric feeding with success in large numbers of patients. Three clinical situations where mercury or tungsten weighted tubes offer advantages over fine bore tubes have been defined. Significant advantages in patients with concurrent endotracheal intubation, gastric atony and severe oesophageal stricturing are described.     

Quality of Life in a Randomized Trial of Nasogastric Tube Feeding in Acute Pancreatitis

Background: Recent clinical studies have shown that nasogastric tube feeding is safe in the majority of patients with acute pancreatitis. Patient‐reported outcomes are important, but the impact of nasogastric tube feeding on the quality of life has not been investigated. This study aims to compare quality of life between nasogastric tube feeding and nil‐by‐mouth groups during and after hospitalization. Methods: Patient‐reported outcomes were recorded daily in a patient diary during hospitalization. The Abdominal Surgery Impact Scale questionnaire was used to determine patients' quality of life. The patients were then followed up at 1 week and 1, 3, and 6 months after discharge. Results: While 17 patients were randomized to nasogastric tube feeding, 18 were put on nil‐by‐mouth. The overall quality of life and individual domains did not differ significantly between the groups during hospitalization (P = .500) or follow‐up. For the entire cohort, individual quality‐of‐life domains during hospitalization improved significantly, including functional impairment (P < .001), pain (P < .001), sleep (P = .035), and psychological function (P < .001). Quality of life further improved for all patients from time of hospital discharge to 3 (P = .002) and 6 months follow‐up (P < .001) but not to 1 week and 1 month. Conclusions: The use of nasogastric tube feeding, in comparison with nil‐by‐mouth, does not impair patients' quality of life. Given the clinical benefits of nasogastric tube feeding, nasogastric feeding should be considered the first‐line approach in all acute pancreatitis patients requiring enteral nutrition.