The insertion of a Ryle's tube has long been considered standard of treatment. The effective insertion of a nasogastric tube (NGT) or orogastric tube (OGT) in an anaesthetized, intubated, or comatose patient in the operating room or intensive care unit looks to be rather difficult. Most NGT insertions in aware, agreeable patients are carried out using the "push and swallow" technique [1]. It is the most frequent technique carried out on individuals having elective thoracic and abdominal surgery. In laparoscopic procedures, the stomach obstructs the camera's field of view. Placing OGT causes the stomach to deflate, which improves the image and lowers the risk of gastric perforation.

With a 50% failure rate on the first try, inserting an orogastric or nasal tube into a patient who is asleep is challenging for anesthesiologists [2]. The patient's inability to swallow while unconscious and the presence of an inflated cuff in the trachea, which could constrict the esophageal lumen, are the causes of this. The insertion of Ryle's tube is obscured in anaesthetized, unconscious individuals due to loss of oropharyngeal muscular tone.

In addition to the traditional methods for facilitating NGT, a number of new techniques have been developed. These include reverse Sellick's maneuver, digital assistance technique, head flexion, neck flexion with lateral pressure, glide scope, split knot to an intubation stylet, peel away split tracheal tube, ureteral guidewire assisted insertion1 and esophageal guidewire assisted technique [3-5].

Literature Review

200 patients were divided randomly into four groups for the study by Appukutty et al. viz control, guidewire, slit endotracheal tube, and neck flexion with lateral neck pressure. In comparison to the control group, all intervention groups had increased success rates. The slit endotracheal tube group required much more time to implant the NG tube. The two most frequent side effects were bleeding and NG tube kinking. They came to the conclusion that employing a ureteral guidewire as a stylet, a slit endotracheal tube as an introducer, or head flexion with lateral neck pressure can all boost the success rate of NG tube insertion. The simplest method with the highest rate of success and the fewest difficulties is head flexion with lateral neck pressure.

By adding water to the Nasogastric tube, Hung CW et al. [6] attempted to make the tube more stiff (water fill method). This study sought to determine whether water-filled NGTs would make tube insertion easier. Rigid tubes need fewer insertion attempts than flexible tubes, as evidenced by earlier investigations. A control group and a water fill group were divided into two. The two groups' rates of successful insertion were contrasted. The passage of the tube in less than 2 attempts was considered a successful NGT implantation for each patient. 93.5 percent of the water fill group and 65.7 percent of the control group experienced successful insertion. They came to the conclusion that the water fill approach is an easy and quick way to make it easier for intubated patients to insert NGTs.

Alrefaey Kandeel and colleagues [7] did another prospective randomised study in 2017 in which they randomly divided 160 patients into two groups: the control group and the neck flexion with digital facilitation group. They came to the conclusion that the group receiving digital support from NGT had a statistically better overall success rate and first attempt success. This study demonstrated the effectiveness, speed, and safety of using digital assistance with an unconscious or sedated patients as a routine strategy or as a last resort in the event that previous approaches have failed.

Another experiment looked at whether neck flexion helped with nasogastric transit. Rajesh Mahajan and colleagues[8] carried out the study. They selected patients who needed intubation and NGT insertion as a part of their surgery and had normal airways and neck motions. They came to the conclusion that neck flexion, along with the nasogastric tube's curve, tends to retain the tube near to the posterior pharyngeal wall, aiding a smooth entry into the oesophagus.

Another study was carried out by B.S. Vijay Siddhartha and associates [9] in 2017. In this investigation, three techniques—conventional, reverse Sellick's, and neck flexion with lateral pressure—were compared and NGT was introduced in patients undergoing laparoscopic hysterectomies. When compared to the standard approach, the reverse Sellick's group in this study had a greater success rate, followed by the neck flexion with lateral pressure group.

The installation of a nasogastric tube can result in ulceration and bleeding from the nose, pharynx, oesophagus, and stomach, according to research by Agarwal A et al. [10] on nasogastric tube knotting over the epiglottis: a cause of respiratory distress. Accidental tracheopulmonary system insertion could result in pneumothorax, hemothorax, or even death. They described an instance where it knotted over the epiglottis and caused respiratory discomfort that was potentially fatal.

Glide scope was utilised by Moharari RS et al. [11] to assist with the insertion of a nasogastric tube. The video laryngoscope known as the gliding scope is regarded as a useful tool for tracheal intubation. They created this study with the goal of evaluating how well this gadget works when inserting nasogastric tubes. Patients who required surgical insertion of the NGT were split into two groups in this randomised clinical experiment. The NGT was placed in the control group blindly, as is customary in operating rooms, but in the glide scope group, the tube was placed with the aid of the glide scope. About 85% of the patients in the Glide scope group had successful NGT insertion on the first try, compared to a success rate of 57.5 percent in the control group. The conclusion reached was that the glide scope speeds up NGT insertion and shortens process time.

Kirtania et al. [12] carried out another trial in which NGT was introduced using an esophageal guidewire assisted approach. In this study, 480 adult patients undergoing general anaesthesia with neuromuscular relaxation for abdominal surgery underwent random assignment to one of two groups: the experimental group receiving the experimental procedure of esophageal guidewire with manual forward displacement of larynx, or the control group. They came to the conclusion that in sedated and tracheally intubated patients following the attempt, esophageal guidewire assisted insertion with manual forward laryngeal displacement approach most usually resulted in accurate positioning of the NGT. The method takes less time than traditional insertion approach and was linked to a lower incidence of procedure-related injuries.

In patients who had undergone anaesthesia and been intubated, Mandal and colleagues [13] examined four methods of inserting nasogastric tubes. A randomised control experiment was conducted. They came to the conclusion that the conventional way was not as effective as the reverse Sellick's, neck flexion with lateral neck pressure, and guide wire assisted techniques. The overall success percentage of the several modified approaches for NGT insertion in the study was consistent with Appukutty and Shroff's results. The reverse Sellick's group had the best success rate of NGT insertion at the first attempt (86%) whereas the ureteral guide wire group had the highest success rate at the second attempt (22 %). Failure rate in the traditional group was higher (30%).

Reverse Sellick's manoeuver, neck flexion with lateral neck pressure and guide wire-assisted techniques are all better alternatives to the conventional method for successful, quick and reliable NGT insertion with permissible adverse events in anaesthetised, intubated adult patients. Further trials are recommended to strengthen the validity of the results obtained from this critical review.

1. Fakhari S. et al. "Split endotraceal tube as a guide tube for gastric tube insertion in anesthetized patients: a randomized clinical trial."J. Cardiovasc. Thorac. Res. 2009, pp. 17–22.

2. Appukutty J, Shroff P.P. "Nasogastric tube insertion using different techniques in anesthetized patients: a prospective, randomized study." Anesth. Analg. 2009, pp. 832–835.

3. Parris W.C. "Reverse Sellick maneuver." Anesth. Analg., vol. ,no. , 1989, pp. 423.

4. Mahajan R, Gupta R. "Another method to assist nasogastric tube insertion."Can. J. Anaesth., vol. 52, no. 6, 2005, pp. 652–653.

5. Kwon O.S. et al. "Endotracheal tube-assisted orogastric tube insertion in intubated patients in an ED." Am. J. Emerg. Med. 2015, pp. 177–180.

6. Hung C.W. and Lee W.H. "A novel method to assist nasogastric tube insertion." Emerg. Med. J. 2008, pp. 23–25.

7. Kandeel A.et al. "Digital assistance of nasogastric tube insertion in intubated patients under general anesthesia." Saudi J. Anaesth., vol. 11, no. 3, 2017, pp. 283–286.

8. Siddhartha B.S. et al. "Nasogastric tube insertion in anesthetized intubated patients undergoing laparoscopic hystrectomies." Anesth. Essays Res. 2017, pp. 550–553.

9. Agarwal A. et al. "Nasogastric tube knotting over the epiglottis: a cause of respiratory distress." Anesth. Analg., 2002, pp. 1659–1660.

10. Moharari R.S. et al. "The glidescope facilitates nasogastric tube insertion: a randomized clinical trial." Anesth. Analg., vol. 110, no. 1, 2010, pp. 115–118.

11. Kirtania J. et al. "Esophageal guidewire-assisted nasogastric tube insertion in anesthetized and intubated patients: a prospective randomized controlled study." Anesth. Analg., vol. 114, no. 2, 2012, pp. 343–348.

12. Mandal M.C. et al. "Comparison of four techniques of nasogastric tube insertion in anaesthetised, intubated patients: a randomized controlled trial." Indian J. Anaesth., vol. 58, no. 6, 2014, pp. 714–718.