Polysomnographic Assessment on Osahs Outcomes in Patients with Nasal Obstruction Undergoing Septoplasty with Partial Inferior Turbinectomy

Abstract

The relationship between nasal obstruction and obstructive sleep apnea has raised interest among otolaryngologists since years. There are studies that suggest that surgical correction of nasal obstruction improves sleep quality and reduces symptoms of sleep apnea. This lead to our study to understand the effect of nasal surgery on obstructive sleep apnea hypopnea syndrome (OSAHS). Aim: To assess the effect of nasal surgery in improvement in Obstructive Sleep Apnoea Hypopnoea Syndrome in patients with nasal obstruction by Polysomnography (PSG). Material and methods: This study included 30 patients with nasal obstruction who underwent septoplasty and/or turbinate reduction procedure with pre and post operative assessment of respiratory distress index (RDI) including apnoea hypopnoea index (AHI), obstructive apnoea index (OAI), Snoring Index (SI) using polysomnography (PSG). Result: Nasal correction surgery showed statistically significant improvement (p-value < 0.001) in RDI from 13.66 to 6.66, OAI from 6.34 to 3.18 and Snoring Index from 161.77 to 62.23 as assessed by polysomnography. There was statistically significant improvement in minimal saturation levels (during sleep) and positional sleep apnoea. Conclusion: Isolated nasal surgery like septoplasty and/or turbinate reduction improved sleep parameters and alleviated OSA symptoms in patients with static nasal obstruction and obstructive sleep apnoea/hypopnoea syndrome. However, patients with multilevel or dynamic airway obstruction may need further intervention.

Introduction

The subsite of respiratory tract that first receives air is the nasal cavity which conditions the inspired air as it passes along lower airways. Any anatomical or pathological disorder of nasal cavity will hamper the volume and flow of inspired air, compromising airflow to lungs and increasing the effort of breathing [1].

Decrease in cross-sectional area of nasal cavity due to static or dynamic obstruction increases resistance and causes downstream inspiratory collapse of lower airways [2, 3]. This worsens the already compromised airway causing obstructive sleep apnoea/hypopnea syndrome (OSAHS) with apnoeic- hypopneic events, snoring, daytime sleepiness, etc. OSAHS is associated with the risk of development of medical co-morbidities, mood and personality changes, impaired daytime performance and quality of life [4, 5], risk of motor vehicle accidents [6–8].

There are studies suggesting that correction of nasal obstruction improves symptoms of obstructive sleep apnoea hypopnoea syndrome [9, 10]. With significant prevalence of deviated nasal septum (76%) [11, 12] and turbinate hypertrophy causing nasal obstruction in general population, we aim to assess the effect of nasal surgery in improvement in Obstructive Sleep Apnoea Hypopnoea Syndrome in patients with nasal obstruction by Polysomnography (PSG).

Materials and Methodology

Sources of data

Patients attending ENT OPD in tertiary care medical centre Chigateri Government Hospital and Bapuji Hospital, the teaching hospitals attached to JJM medical college, Davangere were included.

Sample size

A sample size of 30 was estimated based on prevalence of OSA in Indian population.

Study Design

Observational clinical study.

Duration of Study

November 2022 to April 2023 i.e., 6 months.

Sampling Criteria

Inclusion criteria-

• Age above 18 years;

• Either gender;

• Patients with unilateral or bilateral nasal obstruction;

• Patients resistant to conservative medical management;

• Patients requiring surgical intervention- septoplasty and/or turbinate reduction.

Exclusion criteria-

• Patients with allergic rhinitis, chronic rhinosinusitis with or without polyp;

• Patients with BMI > 40 kg/m²;

• Patients with history of smoking or alcohol consumption;

• Patients with uncontrolled hypertension, uncontrolled diabetes, heart failure;

• Patients with history of chronic obstructive pulmonary diseases (COPD), asthma, TB, restrictive lung diseases, and.

• Patients lost during follow up.

Data Collection Method

Patients presenting with nasal obstruction to ENT OPD and those matching the inclusion and exclusion criteria were included in the study after taking written and informed consent.

Relevant clinical and demographical data was obtained from the patients, following which they were subjected to detailed ear nose throat examination and computed tomography of nose and paranasal sinus (CT nose and PNS). Overnight Polysomnography was performed the night before surgery using a portable PSG device and following parameters were obtained- respiratory distress index (RDI) including apnoea hypopnoea index (AHI), obstructive apnoea index (OAI), central apnoea (CAI) positional sleep apnoea (PSA), desaturation and snoring index (SI).

All patients underwent septoplasty under general anaesthesia. A conventional septoplasty with elevation of mucoperichondrial and mucoperiosteal flaps and removal of deviated parts of bony and cartilaginous nasal septum was done. Flaps were repositioned. Patients with hypertrophied inferior turbinates underwent additional partial inferior turbinectomy procedure. Nasal packs were placed in both nasal cavities. Post operatively, nasal packs were removed after 48 h. All of them received the same treatment, including antibiotics, analgesic with nasal douching for 10 days after surgery. Polysomnography was repeated after three weeks.

Statistical Analysis

Categorical data was represented in the form of frequency and percentage. Association between variables was assessed with Chi Square Test. Quantitative data was represented as Mean & Sd. Comparison of variables was done with Unpaired t test. Follow up assessments was done with Paired t test. A p value of < 0.05 was considered statistically significant in this study.

Results

This study included 30 patients who met inclusion and exclusion criteria and who completed the follow up. There were 22 (73%) males and 8 (27%) females categorised in four age groups as shown in Table 1; 5 (16.7%) in less than 20 years, 18 (60%) in 21-30years, 4(13.3%) in 31–40 years and 3 (10%) in more than 40 years. The mean body mass index (BMI) of the patients included was 22.38 ± 3.3, out of which 3(10%) were underweight, 22(73.3%) were of normal BMI, 5(16.7%) were overweight as depicted in Tables 2 and 3.

Table 1.

Gender Distribution

Gender	No of Cases	Percent
Male	22	73.0
Female	8	27.0
Total	30	100.0

Table 2.

Body Mass Index (in kg/m²)

Parameters	Mean	Sd
Weight(kg)	62.37	10.05
Height(m)	1.67	0.05
BMI (kg/m2)	22.38	3.38

Inference: Mean body mass index of study population was 22.38 kg/m²

Table 3.

Distribution of BMI in study population

BMI	No of Cases	Percent
Under Weight	3	10.0
Normal Weight	22	73.3
Over Weight	5	16.7
Total	30	100.0

Inference: 3 patients in our study population were underweight, 22 were of normal weight and 5 were overweight. (BMI- body mass index)

All patients presented with nasal obstruction as their chief complain and underwent surgery. The pre operative and post operative polysomnography data was compared as shown in Table 4. There was improvement in RDI from (13.66 ± 4.16) pre operatively to (6.66 ± 2.99) post operatively with statistically significant difference (p-value < 0.001). The OAI decreased from (6.34 ± 2.10) before surgery to (3.18 ± 1.92) post-surgery which was statistically significant difference (p-value < 0.001). The Snoring Index decreased from (161.77 ± 66.58) pre operatively to (62.23 ± 32.20) post operatively which was statistically significant (p-value < 0.001).

Table 4.

Statistical analysis of sleep parameters

Parameters	Pre-op Mean	Pre-op SD	Post op Mean	Post op SD	Mean difference	t value	p value
RDI	13.66	4.16	6.66	2.99	7.00	13.370	0.001
OAI	6.34	2.10	3.18	1.92	3.17	10.984	0.001
CAI	2.84	1.37	1.18	0.71	1.66	6.907	0.001
Lowest spO2 (%)	85.27	3.80	91.90	1.24	-6.63	-10.414	0.001
RDI supine / RDI non supine ratio	2.60	0.94	1.25	0.56	1.35	8.412	0.001
Snoring index	161.77	66.58	62.23	32.20	99.53	9.526	0.001

Inference: RDI- respiratory distress index, OAI- obstructive apnoea index, CAI- central apnoea index

p value < 0.05 is statistically significant

The minimal saturation during sleep improved from (85.27 ± 3.80) before surgery to (91.9 ± 1.24) after surgery which was statistically significant (p < 0.001). Furthermore, there was improvement in supine and non-supine RDI ratio from (2.60 ± 0.94) to (1.25 ± 0.56) with statistically significant p-value (< 0.001).

Discussion

Snoring is most frequently reported symptom (70–95%) of OSAHS [13] but it is so common in general population (males 35–45%, females 15–28%) [14, 15] that it is considered a poor indicator of obstructive sleep apnoea/ hypopnea syndrome (OSAHS). The characteristic snoring pattern seen in OSAHS is one loud snore or brief gasps alternating with 20 to 30 s period of silence. 19 out of 30 patients in our study had snoring symptom as reported by their bedpartners. Our study showed a significant reduction in snoring index (SI) with comparatively reduced snoring as witnessed by the bedpartners after surgery with reduced daytime sleepiness or fatigue, improved mood and concentration levels.

Obstructive apnoea is next common symptom of OSAHS and measured as obstructive apnoea index (OAI) - number of apnoeic episodes in an hour that lasted for more than 10 s in presence of an effort to breathe. And respiratory distress index (RDI) is defined as number of apnoea and hypopnoea episodes per hour. Chong et al. provided evidence that nasal correction surgery improved nasal airway patency and reduced OSA severity in 56% subjects [16]. The study conducted by S. T. Kim et al. showed that there was improvement in RDI and OAI in OSA patients after nasal surgery but the degree of improvement differed between individuals with postoperative RDI change being smaller in patients with high preoperative RDI and severe sleep apnoea than in mild OSA patients [17]. In our study there were 18 patients with mild OSA and 12 patients with moderate OSA, of which degree of postoperative RDI change was comparatively more in mild OSA patients.

Nocturnal episodes of oxygen desaturation result in dull aching type of headaches lasting for 1 to 2 h requiring analgesics in about 50% of OSAHS patients [18, 19]. 8 out of 30 patients in our study complained of headache associated with nasal obstruction which alleviated after surgery. Patients reported a feeling of refreshment after sleep and reduced daytime irritability and anxiety.

In patients with OSAHS, frequency and duration of apnoea could be influenced by body position which is termed as position - dependent obstructive sleep apnoea (POSA). As per Cartwright’s classification, the ratio of RDI in supine to non-supine positions more than or equal to 2 is taken as POSA [20]. In our study, there was statistically significant improvement in the ratio from (2.60 ± 0.94) to (1.25 ± 0.56) with positional therapy after surgery.

Furthermore, it has been recognised that women present with symptoms (other than typical symptoms) - insomnia, fatigue, myalgias, morning headaches [21, 22], amenorrhoea, dysmenorrhoea [23]. They may underestimate the symptom severity as compared to men which contributes to under recognition of OSA in women [24]. Hence, women require higher index of suspicion for diagnosis of OSAHS.

Conclusion

From our study it can be concluded that nasal obstruction due to deviated nasal septum, hypertrophied turbinate which is a static type of obstruction, on surgical correction minimised nasal resistance and maintained nasal airway patency. This ultimately alleviated the symptoms of OSAHS as seen by statistically significant improvement in RDI, OAI, Snoring Index parameters of polysomnographic assessment.

However, OSAHS can be caused by static or dynamic obstruction occurring at any level along the airway which needs further evaluation and intervention accordingly.

Results

Statistical Analysis

Categorical data was represented in the form of frequency and percentage. Association between variables was assessed with Chi Square Test. Quantitative data was represented as Mean & Sd. Comparison of variables was done with Unpaired t test. Follow up assessments was done with Paired t test. A p-value of < 0.05 was considered statistically significant in this study.

Authors Contribution

All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Dr Syeda Muskaan. The first draft of the manuscript was written by -Dr Syeda Muskaan and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Funding

The authors have no relevant financial or non-financial interest to disclose.

Data Availability

The data used in this study was not used/published in any other publications.

Code Availability

The data was compiled and analysed using IBM SPSS STATISTICS version 28.

Declarations

Conflict of Interest

The Authors declare that there is no conflict of interest.

Ethics Approval

The study was done after approval of the Institutional Ethics committee from JJM Medical College, Davangere, Karnataka, India in accordance with ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Consent to Participate

Written informed consent was taken from all the patients.

Consent for Publication

All authors have reviewed the manuscript and approved the version to be published.