Comparison of Hemodynamic Changes to Nasal Application of Lignocaine Jelly versus Lubricant Gel and Responses to Ryle's Tube Insertion Following Their Use in Patients Under General Anesthesia.

BACKGROUND: Awake patients complain of burning sensation following nasal application of lignocaine jelly. AIM OF THE STUDY: The aim of the study was to assess hemodynamic changes, ease of insertion, number of attempts taken, and time required for insertion of Ryle's tube following nasal application of 2% lignocaine jelly versus lubricant gel in patients undergoing surgeries under general anesthesia. SETTINGS AND
DESIGN: This was a prospective, randomized, open-label study conducted in a tertiary care institute. SUBJECTS AND METHODS: Eighty patients undergoing surgeries under general anesthesia who required insertion of a Ryle's tube were included. In Group A, 2% lignocaine jelly was used, whereas in Group B, lubricant gel was used prior to Ryle's tube insertion, after induction of anesthesia. Hypertension and/or tachycardia were managed by increasing sevoflurane by 0.5%-1%, followed by propofol bolus of 0.5 mg.kg-1. STATISTICAL TESTS USED: Chi-square test and Independent samples t test.
RESULTS: Both heart rate and mean arterial pressure were significantly higher at 1 min after nasal application of lignocaine jelly and 1 and 5 min after Ryle's tube insertion in Group A compared to Group B. Ease of insertion of Ryle's tube, number of attempts, and time taken for insertion were comparable in both groups. Significantly higher number of patients in Group A required sevoflurane to be increased and needed propofol boluses.
CONCLUSION: Use of lubricant gel for aiding insertion of Ryle's tube in patients under general anesthesia was associated with attenuated heart rate and blood pressure responses without affecting the ease, number of attempts, or time taken for successful insertion of the Ryle's tube. Copyright:

INTRODUCTION

Ryle's tube insertion is a common procedure done during surgeries to decompress stomach and also for feeding the patients in the postoperative period. Lignocaine jelly is commonly used prior to urinary catheterization, urological procedures, and nasogastric tube insertion, etc., for smooth passage of the tubes and also to provide topical anesthesia.[123] Often, it has been observed that awake patients complain of burning sensation, and tachycardia and hypertension are observed in anesthetized patients following nasal application of lignocaine jelly.

The rationale of conducting the present study was that if use of 2% lignocaine jelly was found to cause exaggerated hemodynamic responses compared to use of plain lubricant gel, a change in current practice could be recommended for Ryle's tube insertion under general anesthesia. The primary objective of the present study was to assess the mean arterial pressure (MAP) changes that occur 1 min following nasal application of 2% lignocaine jelly versus lubricant gel for insertion of Ryle's tube in patients undergoing surgeries under general anesthesia. The secondary objectives included assessment of heart rate response to nasal application of 2% lignocaine jelly versus lubricant gel and the hemodynamic responses to Ryle's tube insertion following use of both drugs. Need for intervention in the form of increasing sevoflurane concentration and propofol bolus administration for control of tachycardia or hypertension in both groups as well as the ease of insertion of Ryle's tube, number of attempts taken, and the time required for insertion were also compared.

SUBJECTS AND METHODS

It was a prospective, randomized, open-label study conducted after obtaining the Institutional Ethical Committee clearance (IEC-AIMS-2019-ANES-271) and was registered in Clinical Trial Registry India (CTRI/2020/01/022945). Patients undergoing surgeries under general anesthesia who required insertion of a Ryle's tube and aged 20–70 years, belonging to American Society of Anesthesiologists physical status (ASA PS) classes 1–3 were included in the study. Those patients with a history of allergy to local anesthetics, patients with abnormal coagulation, deviated nasal septum, or nasal polyps, and those requiring nasal intubation were excluded from the study.

There were two groups and the patients were randomly allocated to either of the two groups, Group A or B, based on computer-generated random sequence of numbers. In Group A, 2% lignocaine jelly was used, whereas in Group B, a lubricant gel (GenTeal Gel ®, NOVARTIS) was administered nasally prior to Ryle's tube insertion. Concealment of allocation was done using sequentially numbered opaque-sealed envelopes. Before induction of anesthesia, the nostril which was more patent was identified, by asking the patient to breathe in and out while closing the other, and was decongested with oxymetazoline drops.

All patients received anesthesia as per a standardized protocol. In the operation theater, a large bore intravenous cannula was placed under local anesthesia. Preinduction monitors such as electrocardiogram, noninvasive blood pressure monitor, and pulse oximeter were attached. Following preoxygenation for 3 min, all patients received intravenous glycopyrrolate 0.2 mg, fentanyl 2 μg.kg−1 body weight, and midazolam 2 mg. Induction was performed with propofol 1.5–2.5 mg.kg−1 body weight till there was loss of response to verbal commands. After ensuring ability to mask ventilate, patients were paralyzed with vecuronium 0.1 mg.kg−1 body weight and ventilated with 2% sevoflurane in oxygen for 3 min and intubated with 2% sevoflurane in oxygen for 3 min and were intubated with 8.0 or 7.0 mm internal diameter cuffed endotracheal tube as appropriate. The patients were then mechanically ventilated with 2% sevoflurane in 1:1 air oxygen mixture with tidal volume of 6–8 mL.kg−1 body weight with a respiratory rate of 12–15.min−1 to maintain end-tidal carbon dioxide levels (EtCO2) between 35 and 45 mm Hg.

Ten minutes later, a dollop of either 2% lignocaine jelly (Group A) or lubricant gel (Group B) was applied to the more patent nostril. The Ryle's tube was inserted and the ease, attempts, and time taken for insertion were noted. Heart rate and MAP were documented before and after premedication, following induction, 1, 5, and 10 min after intubation, 1 min after nasal application of the test drug, and 1 and 5 min after Ryle's tube insertion.

More than 20% increase in heart rate or MAP from baseline was considered as tachycardia or hypertension, respectively. Any observed hypertension and/or tachycardia was managed by increasing sevoflurane by 0.5%–1%, followed by propofol bolus of 0.5 mg.kg− 1. If tachycardia or hypertension persisted despite these measures, labetalol 5 mg in incremental doses was administered intravenously. Need for increasing sevoflurane concentration, propofol bolus, and labetalol administration, if any, after test drug application and Ryle's tube insertion were also noted.

Ease of insertion was classified as easy, moderate, hard, and impossible. Time taken for insertion of Ryle's tube was calculated from the time of introducing the Ryle's tube to the nostril till confirmation of correct placement by auscultation. Number of attempts taken for successful placement was noted. If the Ryle's tube was fully taken out of the nostril and reintroduced again, it was counted as an additional attempt.

As there was no similar study published, we initiated the present study as a pilot study in 40 patients with 20 in each group. The mean MAP at 1 min after application of lignocaine jelly and lubricant gel was found to be 102.6 ± 11.9 mm Hg and 93.3 ± 13.3 mm Hg, respectively. With a mean difference of 9.3, with 95% confidence interval and 90% power, the minimum required sample size to obtain statistically significant result, with P < 0.05, was calculated as 39 patients per group. Therefore, we recruited 40 patients into each group.

Chi-square test was used to compare the categorical variables of Group A and B. Independent samples t-test was used to compare the continuous variable in Group A and B. Statistical analyses were conducted using SPSS Version 20.0 for Windows (IBM Corporation, Armonk, NY, USA).

RESULTS

Results of 80 patients were analyzed [Table 1]. The mean age, weight, and the distribution of ASA PS and gender were comparable in both groups [Table 2]. The baseline HR and MAP were comparable between the groups. The hemodynamic variables did not show any statistically significant difference after premedication, following induction, 1, 5, and 10 min after intubation. Both HR and MAP were significantly higher at 1 min after nasal application of lignocaine jelly and 1 and 5 min after Ryle's tube insertion in Group A compared to Group B [Tables 3 and 4]. Ease of insertion of Ryle's tube and number of attempts taken for insertion were comparable in both groups. The mean time taken for insertion was also similar. The number of patients in whom sevoflurane had to be increased during Ryle's tube insertion was significantly higher in Group A. Percentage of patients who needed propofol bolus was also significantly higher in Group A [Table 5]. No patient in either groups required labetalol for control of blood pressure.

Table 1

Consort flow diagram

Table 2

Comparison of demographics and American Society of Anesthesiologists physical status

Variables	Group A	Group B	P
Age, mean±SD	48.67±4.32	50.27±3.41	0.069
Weight, mean±SD	62.53±4.34	61.97±5.41	0.611
Gender, n (%)
Male	24 (60)	26 (65)	0.744
Female	16 (40)	14 (35)
ASA PS 1, n (%)	18 (45)	20 (50)	0.752
ASA PS 2-3, n (%)	22 (55)	20 (50)

ASA PS=American Society of Anesthesiologists physical status, SD=Standard deviation

Table 3

Changes in mean heart rate

Time	Mean±SD		P
	Group A	Group B
Baseline	94.60±4.82	93.25±3.22	0.145
After premedication	92.9±10.46	94.58±6.50	0.607
After induction	86.65±15.29	84.7±10.37	0.64
1 min after intubation	105.35±9.44	103.7±5.64	0.775
5 min after intubation	99.08±0.86	99.10±0.84	0.896
10 min after intubation	96.3±10.56	95.28±9.44	0.386
1 min after nasal application	108.85±8.84	95.40±5.95	<0.001
1 min after Ryle’s tube insertion	100.95±6.91	94.80±5.86	0.006
5 min after Ryle’s tube insertion	96.02±9.2	92.72±6.15	0.04

SD=Standard deviation

Table 4

Changes in mean arterial pressure

Time	Mean±SD		P
	Group A	Group B
Baseline	86.04±14.59	86.84±15.36	0.790
After premedication	78.4±7.8	77.6±11.0	0.755
After induction	78.57±7.14	80.60±11.38	0.290
1 min after intubation	95.37±12.57	98.74±21.72	0.347
5 min after intubation	93.9±8.4	92.9±11.3	0.704
10 min after intubation	84.7±10.37	86.65±15.29	0.640
1 min after nasal application	98.7±12.4	90.0±8.4	0.004
1 min after Ryle’s tube insertion	94.98±5.4	88.88±8.47	0.003
5 min after Ryle’s tube insertion	93.38±3.28	87.85±5.7	<0.001

SD=Standard deviation

Table 5

Comparison of number of times sevoflurane increased, propofol bolus administered, attempts, and time taken for insertion and ease of insertion

Variable	Group A		Group B		P
	Median	Minimum-maximum	Median	Minimum-maximum
Number of times sevoflurane increased	0	0-1	2	1-3	<0.001
Number of times propofol bolus given	0	0-1	2	2-4	<0.001
Number of attempts taken for successful Ryle’s tube insertion	1	0-2	1	0-1	0.210
Time take for successful Ryle’s tube insertion in sec	Mean 125.93	SD 10.39	Mean 121.23	SD 12.35	0.187
Easy insertion	n=32	80.0%	n=30	75.0%	1.000
Moderate and hard insertion	n=8	20.0%	n=10	25.0%

SD=Standard deviation

DISCUSSION

The present study had shown that use of a lubricant gel instead of lignocaine jelly was associated with reduced hemodynamic responses to application of the topical agent as well as that following Ryle's tube insertion. Use of lubricant gel was associated with reduced use of inhaled and intravenous anesthetics as well as labetalol for control of heart rate and/or blood pressure without affecting ease of insertion of Ryle's tube.

Usefulness of lignocaine jelly for insertion of Ryle's tube in awake patients is well proven as the topical anesthesia and lubrication it provides are essential in ensuring patient comfort and success during insertion. Application of lignocaine jelly to mucosa is known to result in severe burning, stinging, or irritation. However, these complaints are usually overlooked in awake patients. However, this discomfort can result in stimulation of sympathetic nervous system. The resultant accelerated hemodynamic effects could cause adverse events in susceptible patients.[45]

The composition of lignocaine jelly includes lignocaine hydrochloride with preservatives such as methylparaben and propylparaben. As the preservative-free solution of lignocaine for intravenous administration does not produce burning sensation on nasal application, it is highly probable that the preservatives added in lignocaine jelly could be the reason for irritation when applied to nasal mucosa. GenTeal® Gel, the lubricant gel we used, contains hydroxypropyl methylcellulose (hypromellose) 0.3% for ophthalmic use.

The physiological manifestations of the stress response to anesthesia and surgery are increases in heart rate and blood pressure as well as intraoperative hyperglycemia.[678] Under general anesthesia, it is always advisable to avoid or blunt events that cause stimulation of the sympathetic nervous system, which add to the stress response and may adversely affect patient outcome.[910] Under general anesthesia any agent which provides lubrication for smooth passage of the Ryle's tube only is needed since there is no requirement for additional local analgesia.

Ryle's tube insertion was performed in our study 10 min after tracheal intubation since we wanted the hemodynamic response following laryngoscopy and intubation to subside to reduce bias. The increased interventions such as use of propofol boluses and need for increasing sevoflurane concentration, in turn, reflected the accelerated hemodynamic responses observed after lignocaine application. Comparable number of attempts and time taken for insertion of Ryle's tube in both groups in our study indicate that use of lubricant gel is as effective as lignocaine jelly for aiding Ryle's tube insertion under general anesthesia. Hence, based on the observations of our study, we recommend use of lubricant gel instead of lignocaine jelly for Ryle's tube insertion in patients under general anesthesia.

The strong point of our study was that there is no similar research published, which looked into the possibility of an added stress response that can happen under general anesthesia on application of lignocaine jelly to the nostril for insertion of Ryle's tube. Our study had drawbacks as it was not a blinded one. The results of the study are not applicable to awake patients as lubricant gels do not provide topical anesthesia.

CONCLUSION

Use of lubricant gel for aiding insertion of Ryle's tube in patients under general anesthesia was associated with attenuated heart rate and blood pressure responses without affecting the ease, number of attempts, or time taken for successful insertion of the Ryle's tube.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.