Comparison of different methods of nasogastric tube insertion in anesthetized and intubated patients: A meta-analysis

Table 1 Summary of the studies included in this meta-analysis and systematic review

Ref.	Country	Sample size	Study participant characteristics	Practitioner inserting NGT with level of expertise	Study groups	Key outcome(s)
Zhao et al[13], 2018	China	110	Patients with cerebral hemorrhage or traumatic brain injury	Not specified	Control group (C): Nasogastric tube (NGT) insertion using conventional technique i.e., with head in a neutral position; Intervention group (I): Nasogastric tube insertion in right lateral decubitus position	Success rate on 1st attempt: C = 36/54 (66.7%); I = 50/56 (89.3%). Overall success rate of insertion: C = 47/54 (87.0%); I = 55/56 (98.2%). Intubation time, mean (SD): C = 114.1 (35.6) s; I = 77.9 (33.5) s. Complication rate: (1) Gag reflex: C = 20/54 (37.0%); I = 7/56 (12.5%); (2) Cough: C = 8/54 (14.8%); I = 1/56 (1.8%); (3) Mucosal bleeding: C = 14/54 (25.9%); I = 3/56 (5.4%); and (4) No major adverse events in both groups
Mandal et al[14], 2018	India	195	Adult patients undergoing abdominal surgery	Not specified	Group A: Conventional; Group B: Frozen NGT; Group C: Reverse Sellick’s manoeuvre	Success rate on 1st attempt: Group A = 29/65 (44.6%); Group B = 45/65 (69.2%); Group C = 59/63 (93.6%). Overall success rate of insertion: Group A = 45/65 (69.2%); Group B = 55/65 (84.6%); Group C = 60/63 (95.2%). Intubation time, mean (SD): Group A = 42.2 (21.4) s; Group B = 42.1 (13.2) s; Group C = 31.5 (9.5) s. Complication rate: (1) Mucosal bleeding: Group A = 3/65 (4.6%); Group B = 20/65 (30.8%); Group C = 0/63 (0.0%); (2) Coiling: Group A = 12/65 (18.5%); Group B = 16/65 (24.6%); Group C = 5/63 (7.9%); (3) Kinking: Group A = 8/65 (12.3%); Group B = 6/65 (9.2%); Group C = 0/63 (0.0%); and (4) No major adverse events in any of the three groups
Chun et al[15], 2009	Korea	100	Patients undergoing elective general anesthesia	Not specified	Patient placed in a neutral position with moderate head elevation; Control (C)-normal silicone NGT; Intervention (I)-frozen NGT	Overall success rate of insertion: C = 29/50 (58.0%); I = 44/50 (88.0%). Intubation time, mean (SD): C = 120 (133) s; I = 83 (43) s. Complication rate: (1) Mucosal bleeding: C = 6/50 (12.0%); I = 3/50 (6.0%); and (2) No major adverse events in any of the groups
Siddhartha et al[16], 2017	India	120	Patients undergoing laparoscopic hysterectomy	Not specified	Group C (Control group): Conventional technique with head in a neutral position and NGT through nostril; Group R: Reverse Sellick’s manoeuvre; Group F: Neck flexion with lateral neck pressure	Success rate on 1st attempt: Group C = 15/40 (37.5%); Group F = 16/40 (40.0%); Group R = 31/40 (77.5%). Overall success rate of insertion: Group C = 30/40 (75.0%); Group F = 31/40 (77.5%); Group R = 37/40 (92.5%). Intubation time; mean (SD): Group C = 25.5 (4.5) s; Group F = 20.5 (4.7) s; Group R = 13.1 (2.6) s. Complication rate: (1) Mucosal bleeding: Group C = 12/40 (30.0%); Group F = 12/40 (30.0%); Group R = 10/40 (25.0%); (2) Coiling: Group C = 25/40 (62.5%); Group F = 12/40 (30.0%); Group R = 7/40 (17.5%); and (3) Kinking: Group C = 3/40 (7.5%); Group F = 3/40 (7.5%); Group R = 3/40 (7.5%)
Appukutty et al[17], 2009	India	200	Patients receiving GA and tracheal intubation for various surgical procedures	Group of four 3rd year anaesthesia residents; all judged proficient in insertion techniques by the authors	Group C (Control group): Conventional technique with head in a neutral position and NGT through nostril; Group W: Guidewire group; guidewire introduced within a 14-F nasogastric tube; Group S: Slit endotracheal group; Group F- Neck flexion with lateral neck pressure	Success rate on 1st attempt: Group C = 17/50 (34.0%); Group W = 33/50 (66.0%); Group S = 41/50 (82.0%); Group F = 41/50 (82.0%). Overall success rate of insertion: Group C = 36/50 (72.0%); Group W = 46/50 (92.0%); Group S = 46/50 (92.0%); Group F = 47/50 (94.0%). Intubation time, mean (SD): Group C = 56 (36) s; Group W = 42 (29) s; Group S = 98 (43) s; Group F = 31 (19) s. Complication rate: (1) Mucosal bleeding: Group C = 0/50 (0.0%); Group W = 0/50 (0.0%); Group S = 11/50 (22.0%); Group F = 0/50 (0.0%); (2) Coiling: Group C = 1/50 (2.0%); Group W = 1/50 (2.0%); Group S = 0/50 (0.0%); Group F = 0/50 (0.0%); and (3) Kinking: Group C = 10/50 (20.0%); Group W = 4/50 (8.0%); Group S = 0/50 (0.0%); Group F = 4/50 (8.0%)
Kwon et al[18], 2014	Korea	56	Intubated patients in the emergency department	By 3 paramedics; 8 h of education and practice on a mannequin for NGT insertion	Control group (C): Conventional technique with head in a neutral position and NGT through nostril; Intervention group (I): Endotracheal tube-assisted insertion through mouth	Success rate on 1st attempt: C = 14/28 (50.0%); I = 28/28 (100.0%). Overall success rate of insertion: C = 18/28 (64.0%); I = 28/28 (100.0%). Intubation time, mean (SD): C = 111.7 (74.5) s; I = 58 (16.9) s. Complication rate: (1) Mucosal bleeding: C = 2/28 (7.0%); I = 5/28 (17.8.0%); and (2) Kinking: C = 5/28 (17.8%); I = 0/28 (0.0%)
Illias et al[19], 2013	Taiwan	150	Patients intubated for gastrointestinal surgery	By 2 experienced anesthesiologists	Control group: Conventional technique with head in a neutral position and NGT through nostril; Group F: Neck flexion with lateral neck pressure; Group L: NGT placed after lifting of the larynx	Success rate on 1st attempt: Control = 26/50 (52.0%); Group F = 41/50 (82.0%); Group L = 44/50 (88.0%). Overall success rate of insertion: Control = 30/50 (60.0%); Group F = 44/50 (88.0%); Group L = 46/50 (92.0%). Intubation time, mean (SD): Control = 26.7 (16.0) s; Group F = 29.5 (14.8) s; Group L = 21.3 (8.4) s. Complication rate: (1) Mucosal bleeding: Control = 5/50 (10.0%); Group F = 1/50 (2.0%); Group L=1/50 (2.0%); (2) Kinking: Control = 20/50 (40.0%); Group F = 8/50 (16.0%); Group L = 6/50 (12.0%); (3) Coiling: Control = 19/50 (38.0%); Group F = 2/50 (4.0%); Group L = 0/50 (0.0%); and (4) Bradycardia: Control = 0/50 (0.0%); Group F = 0/50 (0.0%); Group L = 1/50 (2.0%)
Kavakli et al[20], 2017	Turkey	200	Patients intubated for gastrointestinal surgery	By 3 anaesthesiologists of similar experience	Control group: Conventional technique with head in a neutral position and NGT through nostril; Group L: head in lateral position; Group ET: Endotracheal tube-assisted NGT placement; Group MG: McGrath video laryngoscope-assisted NGT placement	Success rate on 1st attempt: Control = 27/50 (54.0%); Group L = 39/50 (78.0%); Group ET = 50/50 (100.0%); Group MG = 46/50 (92.0%). Overall success rate of insertion: Control = 33/50 (66.0%); Group L = 44/50 (88.0%); Group ET = 50/50 (100.0%); Group MG = 49/50 (98.0%). Intubation time, mean (SD): Control = 62.5 (15.3) s; Group L = 43.4 (7.8) s; Group ET = 82.3 (7.9) s; Group MG = 42.4 (4.2) s. Complication rate: (1) Mucosal bleeding: Control = 10/50 (20.0%); Group L = 9/50 (18.0%); Group ET = 10/50 (20.0%); Group MG = 1/50 (2.0%); and (2) Coiling: Control = 10/50 (20.0%); Group L = 3/50 (6.0%); Group ET = 0/50 (0.0%); Group MG = 1/50 (2.0%)
Wan Ibadullah et al[21], 2016	Malaysia	96	Patients scheduled for surgery under GA requiring tracheal intubation and NGT insertion	Multiple anesthetists proficient in both techniques of insertion	Group A: NGT insertion using GlideScope visualization; Group B: NGT insertion using direct MacIntosh laryngoscope	Success rate on 1st attempt: Group A = 35/47 (74.5%); Group B = 28/48 (58.3%). Overall success rate of insertion: Group A = 46/47 (97.8%); Group B = 46/48 (95.8%). Intubation time, mean (SD): Group A = 17.2 (9.3) s; Group B = 18.9 (13.0) s. Complication rate: (1) Mucosal bleeding: Group A = 4/47 (8.5%); Group B = 4/48 (10.4%); (2) Coiling: Group A = 11/47 (23.4%); Group B = 17/48 (35.4%); and (3) Kinking: Group A = 2/47 (4.3%); Group B = 1/48 (2.1%)
Tsai et al[22], 2012	Taiwan	103	Patients scheduled for gastrointestinal or hepatic surgery under GA	Single anesthetist; practice of both techniques for 2 wk with 20 patients per technique	Control (C): Conventional technique with head in a neutral position and NGT through nostril; Intervention (I)- NGT insertion with help of “Rusch” intubation stylet tied together at the tips by a slipknot	Success rate on 1st attempt: C = 27/50 (54.0%); I = 50/53 (94.3%). Overall success rate of insertion: C = 32/50 (64.0%); I = 52/53 (98.1%). Intubation time, mean (SD): Control= 39.5 (19.5) s; I = 40.3 (23.2) s. Complication rate: (1) Mucosal bleeding: Control = 6/50 (12.0%); I = 6/53 (11.3%); and (2) Kinking: C = 9/50 (18.0%); I = 0/53 (0.0%)
Kirtania et al[23], 2012	India	480	Patients scheduled for gastrointestinal surgery under GA	2 independent operators trained by authors before the study; the operators demonstrated the techniques on one patient each before the study	Group 1: NGT placement with esophageal guidewire with manual forward displacement of larynx; Group 2: Neck flexion with lateral neck pressure	Success rate on 1st attempt: Group 1 = 230/240 (99.2%); Group 2 = 136/240 (56.7%). Overall success rate of insertion: Group 1 = 240/240 (100.0%); Group 2 = 205/240 (85.4%). Intubation time, mean (SD): Group 1 = 54.9 (7.4) s; Group 2 = 90.1 (43.6) s. Complication rate: (1) Mucosal bleeding: Group 1 = 10/240 (4.2%); Group 2 = 36/240 (15.0%); (2) Coiling: Group 1 = 2/240 (0.8%); Group 2 = 104/240 (43.3%); and (3) Moderate injury: Group 1 = 1/240 (0.42%); Group 2 = 9/240 (3.8%)
Shwetha Odeyar et al[24], 2019	India	60	Patients scheduled for laparoscopic or laparotomy under GA	Single anesthesiologist	Group A: Conventional technique with head in a neutral position and NGT through nostril; Group B: Reverse Sellick’s maneuver	Success rate on 1st attempt: Group A = 6/30 (20.0%); Group B = 14/30 (46.7%). Overall success rate of insertion: Group A = 27/30 (90.0%); Group B = 27/30 (90.0%). Intubation time, mean (SD): Group A = 97 (23.1) s; Group B = 84 (17.3) s. Complication rate: Mucosal bleeding: Group A = 2/30 (6.7%); Group B = 1/30 (3.3%)
Ghaemi et al[25], 2013	Islamic Republic of Iran	80	Patients undergoing elective GA and required NGT insertion	Single anesthesiologist	Control (C): Conventional technique with head in a neutral position and NGT through nostril; Intervention (I): NGT insertion same as control except the NGT was equipped with a Nelaton catheter. Nelaton equipped NGT was inserted through nostril as deeply as the Nelaton catheter length. Then the catheter was withdrawn and NGT was inserted further to reach the stomach	Overall success rate of insertion: C = 23/40 (57.5%); I = 36/40 (90.0%). Intubation time, mean (SD): Control = 92 (35) s; Intervention = 80 (43) s. Complication rate: Mucosal bleeding: C = 3/40 (7.5%); I = 5/40 (12.5%)
Kim et al[26], 2018	Korea	70	Patients undergoing gastrointestinal surgery under GA	Single anesthesiologist	Control: Conventional (C) technique with head in a neutral position and NGT through nostril;Intervention (I): NGT insertion using GlideScope and Modified Magill forceps	Success rate on 1st attempt: C = 13/35 (37.1%); I = 35/35 (100.0%). Overall success rate of insertion: C = 26/35 (74.3%); I = 35/35 (100.0%). Intubation time, mean (SD): C = 96.7 (57.5) s; I = 71.3 (22.6) s
Kim et al[27], 2016	Korea	100	Patients undergoing gastrointestinal surgery under GA	Not Specified	Control: Conventional (C) technique with head in a neutral position and NGT through nostril; Intervention (I): NGT insertion same as the control except that a lubricated tube exchanger was used to facilitate insertion	Success rate on 1st insertion: C = 34/50 (68.0%); I = 46/50 (92.0%). Overall success rate of attempt: C = 46/50 (92.0%); I = 50/50 (100.0%). Intubation time; Mean (SD): C = 75.1 (9.8) s; I = 18.5 (8.2) s. Complication rate: (1) Mucosal bleeding: C = 9/50 (18.0%); I = 1/50 (2.0%); and (2) Kinking: C = 10/50 (20.0%); I = 0/50 (0.0%)
Singh et al[28], 2016	India	300	Patients requiring admission to intensive care unit and NGT insertion	3rd year anesthesia residents judged proficient in insertion techniques	Control group: Manual anterior displacement of cricoid cartilage and NGT insertion; Group W: NGT insertion using guidewire; Group B: Combination of Manual anterior displacement of cricoid cartilage and guidewire	Success rate on 1st attempt: Control = 64/100 (64.0%); Group B = 88/100 (88.0%); Group W = 84/100 (84.0%). Overall success rate of insertion: Control = 82/100 (82.0%); Group B = 97/100 (97.0%); Group W = 90/100 (90.0%). Intubation time, mean (SD): Control = 60.2 (20.9) s; Group B = 39.3 (9.6) s; Group W = 42.9 (10.1) s. Complication rate: (1) Mucosal bleeding: Control = 3/100 (3.0%); Group B=7/100 (7.0%); Group W = 7/100 (7.0%); and (2) Kinking: Control = 7/100 (7.0%); Group B = 1/100 (1.0%); Group W = 2/100 (2.0%)
Moharari et al[29], 2010	Iran	80	Patients requiring intraoperative placement of NGT	Single anesthesiologist	Control group (C): Conventional technique with head in a neutral position and NGT through nostril; Intervention (I): NGT inserted and placed using GlideScope visualization	Success rate on 1st attempt: Control = 23/40 (57.5%); I = 34/40 (85.0%). Overall success rate of insertion: Control = 27/40 (67.5%); Intervention = 35/40 (87.5%). Intubation time, mean (SD): Control = 38.6 (29) s; Intervention = 10.9 (9.0) s. Complication rate: Mucosal bleeding: Control = 14/40 (35.0%); Intervention = 8/40 (20.0%)

NGT: Nasogastric tube.

Table 2 Summary of findings based on the pooling of available literature

Techniques compared/outcomes	Success on 1st insertion	Overall success of insertion
Reverse Sellick’s maneuver vs conventional technique	RR 1.94; 95%CI: 1.62-2.31	RR 1.26; 95%CI: 1.04-1.52
Neck flexion with lateral neck pressure vs conventional technique	RR 1.64; 95%CI: 1.10-2.45	RR 1.26; 95%CI: 1.05-1.52
Frozen nasogastric tube vs conventional technique	RR 1.55; 95%CI: 1.13-2.13	RR 1.32; 95%CI: 1.13-1.54
Endotracheal tube-guided vs conventional technique	RR 1.88; 95%CI: 1.52-2.32	RR 1.52; 95% CI: 1.29-1.79
Video-assisted vs conventional technique	RR 1.60; 95%CI: 1.31-1.95	RR 1.41; 95%CI: 1.20-1.64

Conventional technique implies head in a neutral position and nasogastric tube inserted through nostril. RR: Risk ratio; CI: Confidence interval.