Point-of-care ultrasound-guided aspiration of a parapharyngeal abscess to facilitate airway management: A case report

Abstract

BACKGROUND

Deep neck space infections involving the parapharyngeal region can cause severe upper-airway narrowing and make airway management hazardous because of anatomical distortion, edema, and proximity to major cervical vessels. Point-of-care ultrasound (POCUS) may assist by identifying an accessible collection and guiding aspiration in real time.

CASE SUMMARY

A 22-year-old man presented with progressive right-sided neck swelling, voice change, and worsening dyspnoea. 70° laryngoscopy showed a posterior pharyngeal wall bulge with mucosal edema and non-visualisation of the glottis. Contrast-enhanced computed tomography demonstrated a multiloculated parapharyngeal/posterior pharyngeal abscess measuring approximately 82 mm × 76 mm × 40 mm with marked oropharyngeal narrowing. A multidisciplinary airway plan was formulated. With spontaneous ventilation preserved, supplemental oxygen administered, and the patient semi-recumbent, POCUS-guided aspiration was performed through a right submandibular approach using colour Doppler and an 18-G, 5-cm echogenic needle. Approximately 60 mL of purulent material was aspirated from the largest safely accessible locule. The patient reported improved respiratory comfort and subsequently tolerated supine positioning. General anaesthesia was then induced, and first-attempt tracheal intubation was achieved using video laryngoscopy with a Cormack–Lehane grade 1 view. Definitive transoral surgical drainage followed. Culture grew Klebsiella pneumoniae susceptible to piperacillin–tazobactam. The patient was discharged after 7 days and remained asymptomatic at 3-month follow-up.

CONCLUSION

POCUS-guided aspiration may serve as a selective temporising adjunct in carefully chosen patients with severe airway narrowing and an accessible deep-neck collection. However, the observed improvement should be interpreted as temporal rather than proof of a causal increase in airway patency.

Key Words: Parapharyngeal space; Abscess; Airway management; Airway obstruction; Intubation; Intratracheal; Ultrasonography; Case report

Core Tip: Deep neck abscesses with severe pharyngeal distortion can make both awake airway instrumentation and induction of general anaesthesia challenging. In this case, a multiloculated posterior pharyngeal abscess caused marked oropharyngeal narrowing and non-visualisation of the glottis. Point-of-care ultrasound (POCUS)-guided partial aspiration was performed while spontaneous ventilation was maintained as part of an individualised multidisciplinary airway strategy, followed by successful video-laryngoscopic intubation and definitive surgical drainage. POCUS-guided decompression should be considered a selective temporising adjunct, not a replacement for established difficult-airway techniques.

INTRODUCTION

Deep neck space infections, particularly those involving the parapharyngeal space, are uncommon but potentially life-threatening conditions due to their proximity to vital neurovascular structures and the risk of rapid airway compromise[1]. In a series of 185 patients with deep neck infection, the parapharyngeal space was the most frequently involved anatomical space, accounting for 38.4% of cases[1]. These infections often present with non-specific symptoms such as neck swelling, dysphagia, odynophagia, and voice changes, but may progress to significant upper airway obstruction if not promptly recognised and managed[1,2].

Airway management in such patients remains a major challenge for the anaesthesiologist, as distortion of airway anatomy, edema, and mass effect from the abscess can render conventional techniques difficult or hazardous. Loss of airway following induction of general anaesthesia is a critical concern, necessitating careful planning and selection of an appropriate airway strategy[3].

While awake fibreoptic intubation and tracheostomy are established options in anticipated difficult airway scenarios, their feasibility must be individualised in the setting of deep neck infection[3,4]. Point-of-care ultrasound (POCUS) may serve as a useful adjunct by delineating accessible collections and adjacent vascular structures and by enabling real-time image-guided aspiration[5,6].

We describe a patient with a multiloculated posterior pharyngeal abscess causing severe oropharyngeal narrowing and non-visualisation of the glottis, in whom pre-induction POCUS-guided partial aspiration was incorporated into an individualised multidisciplinary airway-management strategy before definitive tracheal intubation and surgical drainage.

CASE PRESENTATION

Chief complaints

A 22-year-old man weighing 50 kg (body mass index, 17.7 kg/m²; American Society of Anesthesiologists physical status II-E) presented with a 3-month history of progressively enlarging right-sided neck swelling, followed by voice change for approximately 1.5 months and progressive dyspnoea over the preceding 5 days. The swelling was associated with pain, and the patient reported worsening dyspnoea in the supine position.

History of present illness

The right-sided neck swelling had progressively enlarged over 3 months. This was followed by change in voice and, more recently, progressive dyspnoea. Because of worsening respiratory discomfort in the supine position, the patient was maintained in a semi-recumbent position at presentation. Dental and oropharyngeal evaluation did not identify a definite odontogenic or tonsillar source of infection.

History of past illness

The patient had no documented major comorbid illness and no known immunocompromising condition. His regular medication history and drug-allergy history were non-contributory.

Personal and family history

Relevant social history, including tobacco, alcohol, and other substance use, was non-contributory. No relevant family history contributing to the present illness was identified.

Physical examination

At presentation, the heart rate was 90 beats/minute, blood pressure was 110/82 mmHg, respiratory rate was 32 breaths/minute, and oxygen saturation was 92% on room air. Because of worsening dyspnoea in the supine position, the patient was maintained semi-recumbent.

Examination revealed diffuse swelling over the right side of the neck, extending posteriorly to the retro-auricular groove and inferiorly to the level of the hyoid bone, crossing the midline along the anterior border of the right sternocleidomastoid muscle. The swelling was firm and non-tender. A characteristic “hot potato” voice was present, suggesting oropharyngeal involvement.

Conventional airway examination demonstrated a mouth opening of 3 cm, Mallampati class II, and adequate neck movement. No additional composite difficult-airway score was recorded. 70° laryngoscopy demonstrated a prominent posterior pharyngeal wall bulge abutting the uvula, with associated mucosal edema, and the glottis could not be visualised (Figure 1).

Figure 1  70° endoscopic view of the oropharynx demonstrating a prominent posterior pharyngeal wall bulge with mucosal edema, and non-visualisation of the glottic opening.

Laboratory examinations

Laboratory investigations showed a white blood cell count of 14000/mm³ and a C-reactive protein level of 4.6 mg/L. Other routine preoperative investigations were within normal limits.

Imaging examinations

Contrast-enhanced computed tomography of the neck demonstrated a multiloculated abscess measuring approximately 82 mm × 76 mm × 40 mm involving the posterior pharyngeal wall and right parapharyngeal space. The collection extended into the right prevertebral, parapharyngeal mucosal, and carotid spaces at the C1-C3 levels, with further extension into cervical lymph node levels IIa, III, and V. Marked narrowing of the oropharyngeal lumen was present (Figure 2).

Figure 2 Contrast-enhanced computed tomography of the neck. A and B: Sagittal (A) and axial (B) images demonstrating a multiloculated parapharyngeal abscess (▲) with extension into the prevertebral and carotid spaces, causing significant narrowing of the oropharyngeal lumen.

Point-of-care ultrasonography of the right submandibular region demonstrated a well-defined anechoic collection lateral to the carotid vessels, with posterolateral extension towards the posterior cervical region. The target collection was located approximately 3 cm beneath the skin surface. Colour Doppler was used to delineate the carotid and adjacent vascular structures and identify an avascular needle trajectory (Figure 3).

Figure 3  Ultrasound image of the right side of the neck showing a well-defined anechoic collection lateral to the carotid vessels with posterolateral extension, consistent with a parapharyngeal abscess.

MULTIDISCIPLINARY EXPERT CONSULTATION

In view of progressive respiratory distress and radiological evidence of significant airway compromise, a multidisciplinary airway plan was formulated jointly by the anaesthesia and otorhinolaryngology teams. The anaesthesia team was responsible for airway assessment, ultrasound-guided aspiration, preservation of spontaneous ventilation, oxygenation, induction of anaesthesia, and tracheal intubation. The otorhinolaryngology team was physically present in the operating theatre and prepared for immediate emergency tracheostomy/front-of-neck access if required.

The primary strategy was ultrasound-guided aspiration while preserving spontaneous ventilation, followed, if clinically appropriate, by video-laryngoscopy-assisted tracheal intubation. Predefined criteria for abandoning this strategy included worsening respiratory distress, inability to maintain oxygenation, haemorrhage, loss of continuous needle-tip visualisation, suspected abscess rupture into the airway, haemodynamic deterioration, or failure to obtain an adequate laryngoscopic view. Immediate surgical airway access was the rescue strategy in the event of failed oxygenation or failed intubation.

FINAL DIAGNOSIS

The final diagnosis was a multiloculated right parapharyngeal/posterior pharyngeal abscess causing marked oropharyngeal narrowing and severe anatomical airway compromise.

TREATMENT

The patient was transferred to the emergency operating theatre and standard monitoring, including electrocardiography, non-invasive blood pressure monitoring, and pulse oximetry, was applied. He remained semi-recumbent with continuous oxygen supplementation via face mask. The trachea was not instrumented before aspiration, and spontaneous ventilation was preserved.

Ultrasound-guided aspiration was performed under strict aseptic precautions. A high-frequency linear-array transducer was placed over the right submandibular region, and the collection was assessed in transverse and longitudinal planes. Because the abscess was multiloculated, the largest safely accessible locule with a clear sonographic window and adequate separation from major vascular structures was selected.

No local anaesthesia or sedation was administered. An 18-G, 5-cm echogenic needle was introduced through a right submandibular approach using an in-plane technique. Needle advancement was performed under continuous real-time ultrasound guidance, with the shaft and tip maintained in view throughout; advancement was paused whenever the needle tip was not clearly visualised. Aspiration was performed using a 10-mL syringe, yielding approximately 60 mL of purulent material, which was submitted for microbiological analysis. The procedure was performed by an anaesthesiologist with approximately 10 years of experience in ultrasound-guided procedures.

Following aspiration, the patient reported improvement in respiratory discomfort and was able to tolerate supine positioning. Anaesthesia was then induced with intravenous midazolam 0.02 mg/kg, fentanyl 2 µg/kg, and propofol 1.5 mg/kg. Neuromuscular blockade was achieved with succinylcholine 75 mg. Tracheal intubation was performed using a Niscomed video laryngoscope fitted with a Macintosh size 3 blade, which demonstrated a Cormack–Lehane grade 1 glottic view (Figure 4). A 7.5-mm internal diameter cuffed endotracheal tube was inserted successfully on the first attempt. Correct placement was confirmed by bilateral chest auscultation and continuous waveform capnography. No desaturation, aspiration, abscess rupture into the airway, or haemodynamic instability occurred.

Figure 4  Video-laryngoscopic view obtained after ultrasound-guided aspiration, demonstrating a Cormack-Lehane grade 1 glottic view.

Definitive surgical drainage was subsequently performed via a transoral approach. Purulent material was evacuated and the abscess cavity was thoroughly irrigated.

OUTCOME AND FOLLOW-UP

Postoperatively, the patient was managed in the intensive care unit (ICU) because of the risk of residual airway edema and remained intubated for 24 hours. Extubation was performed after confirmation of haemodynamic stability, adequate oxygenation, satisfactory spontaneous ventilation, improvement in airway swelling, manageable secretions, and presence of a cuff leak. He was extubated on postoperative day 1 without stridor or respiratory distress.

The patient received piperacillin-tazobactam 4.5 g intravenously every 8 hours, initiated preoperatively by the surgical team before ultrasound-guided aspiration and definitive surgical drainage. Culture of the aspirated purulent material subsequently grew Klebsiella pneumoniae susceptible to piperacillin-tazobactam; therefore, the same regimen was continued for a total of 5 days, along with supportive care. No post-discharge antimicrobial therapy was prescribed. The ICU stay was 2 days, and the patient was transferred to the ward on postoperative day 3. The total hospital stay was 7 days.

At discharge, the patient was clinically stable without respiratory distress, dysphagia, recurrent neck swelling, or other airway-related symptoms. At 3-month follow-up, he remained asymptomatic, with no residual dysphagia, dysphonia, neck symptoms, clinical evidence of recurrence, or requirement for repeat drainage. No follow-up CT or ultrasonography was performed. The chronological course of presentation, intervention, hospitalisation, and follow-up is summarised in Table 1.

Table 1 Chronological timeline of clinical presentation, airway management, treatment, and follow-up.

Time point	Clinical event
3 months before presentation	Progressive right-sided neck swelling began
Approximately 1.5 months before presentation	Voice change developed
5 days before presentation	Progressive dyspnoea developed, with worsening symptoms in the supine position
Day of presentation	HR 90/minute, BP 110/82 mmHg, RR 32 breaths/minute, SpO2 92% on room air. WBC 14000/mm3; CRP 4.6 mg/L
Initial airway assessment	Rigid 70° laryngoscopy showed a prominent posterior pharyngeal wall bulge with mucosal edema and non-visualisation of the glottis
Initial imaging	Contrast-enhanced CT demonstrated an approximately 82 mm × 76 mm × 40 mm multiloculated parapharyngeal/posterior pharyngeal collection with extension into adjacent deep-neck spaces and marked oropharyngeal narrowing
Emergency operating theatre	Multidisciplinary airway plan formulated; patient maintained semi-recumbent with spontaneous ventilation and oxygen via face mask
Pre-induction intervention	POCUS-guided submandibular aspiration performed using an 18-G, 5-cm echogenic needle under colour-Doppler and real-time ultrasound guidance; approximately 60 mL of pus aspirated
Immediately after aspiration	Patient reported improvement in respiratory discomfort and was able to tolerate supine positioning
Definitive airway management	General anaesthesia induced; video laryngoscopy demonstrated a Cormack-Lehane grade 1 view; tracheal intubation achieved on the first attempt
Same operative episode	Definitive transoral surgical drainage and irrigation performed
Postoperative period	Patient remained intubated and was managed in the ICU
Postoperative day 1	Extubated successfully without stridor or respiratory distress
Postoperative days 1-2	Continued ICU observation; no airway-related or respiratory complications
Postoperative day 3	Shifted to the ward
Hospital day 7	Discharged in stable condition without respiratory distress, dysphagia, recurrent neck swelling, or other airway-related symptoms
3-month follow-up	Patient remained asymptomatic, with no clinical evidence of recurrence and no need for repeat drainage; no follow-up CT or ultrasonography was performed

HR: Heart rate; BP: Blood pressure; RR: Respiratory rate; SpO₂: Peripheral oxygen saturation; WBC: White blood cell count; CRP: C-reactive protein; POCUS:Point-of-care ultrasound; ICU: Intensive care unit.

DISCUSSION

Parapharyngeal space infections, although relatively uncommon, present a significant clinical challenge due to their proximity to vital neurovascular structures and their potential for rapid progression to life-threatening airway compromise[1,2]. Clinical features such as “hot potato” voice, dyspnoea in the supine position, and inability to visualise the glottis on endoscopy, as observed in our patient, are important indicators of impending airway obstruction and necessitate urgent intervention[1,2].

The prolonged history of right-sided neck swelling and voice change in this patient was unusual for an uncomplicated acute deep neck infection and prompted consideration of an underlying source or alternative cervical pathology. Potential sources included odontogenic and tonsillar infection, lymphatic disease, congenital cystic lesions, and other chronic neck-space pathology[1,4]. However, no definite primary source was identified on the available clinical and radiological evaluation. The diagnosis of a deep neck abscess was supported by contrast-enhanced CT and subsequently confirmed by aspiration of purulent material.

The primary challenge in these cases lies not only in controlling the infection but also in securing the airway safely in the presence of distorted anatomy. Airway management in such cases is challenging because anatomical distortion, edema, and involvement of the oropharyngeal or laryngopharyngeal spaces can complicate airway control[7]. Conventional direct laryngoscopy may be hazardous, with risks of abscess rupture, aspiration, and failure to visualise the glottis due to posterior pharyngeal wall bulging[7].

Various airway management strategies have been described in patients with deep neck infection. Awake fiberoptic intubation is an established technique for anticipated difficult-airway management and may be particularly useful when substantial airway distortion is expected[7]. Tracheostomy under local anaesthesia provides a definitive airway but is invasive, technically challenging in inflamed and distorted neck anatomy, and associated with potential complications such as bleeding and infection. Video laryngoscopy offers improved visualisation but may still fail when significant mass effect obliterates the oropharyngeal space[5,6]. These considerations emphasise the need for an individualised, predefined airway strategy with immediate rescue options.

In the present patient, the obstruction was predominantly oropharyngeal, with a posterior pharyngeal wall bulge abutting the uvula, mucosal edema, non-visualisation of the laryngeal inlet on preoperative assessment, marked luminal narrowing on CT, progressive respiratory distress, and orthopnoea. Awake fibreoptic intubation was considered; however, the multidisciplinary team judged that passage of a fibreoptic bronchoscope through the severely narrowed residual airway could be technically difficult and might further reduce the available lumen or provoke coughing, bleeding, abscess rupture, or aspiration.

An awake surgical airway was also considered as an alternative definitive strategy. However, because spontaneous ventilation and oxygenation were being maintained and ultrasound demonstrated a safely accessible component of the collection with adequate separation from the major cervical vessels, the multidisciplinary team elected to perform limited ultrasound-guided aspiration as an intermediate step before definitive airway instrumentation. Because the abscess was multiloculated, the procedure targeted only the largest safely accessible locule and was intended to achieve partial decompression rather than definitive source control. Definitive drainage was subsequently achieved by transoral surgical evacuation and irrigation of the abscess cavity. The aspiration was performed without sedation while spontaneous ventilation was preserved, with the otorhinolaryngology team present and prepared for immediate surgical airway access if required. Following aspiration, the patient reported clinical improvement and was able to tolerate supine positioning; on this basis, the team proceeded with induction of general anaesthesia and video-laryngoscopy-assisted tracheal intubation. This sequence should be regarded as an individualised, case-specific strategy rather than as a general alternative to awake fibreoptic intubation or awake surgical airway. Importantly, the pre-intervention airway was assessed using rigid 70° laryngoscopy, whereas the post-intervention airway was assessed using video laryngoscopy, and no repeat endoscopy or quantitative assessment of airway calibre was performed. Accordingly, these observations are not directly comparable, and the contribution of decompression to the subsequent laryngoscopic conditions cannot be determined. The findings are therefore more appropriately interpreted as temporal clinical improvement following partial decompression, followed by successful airway management, rather than proof of a causal improvement in airway patency.

POCUS has an expanding role in the assessment and procedural management of deep neck space infections[6-9]. Ultrasound can delineate a collection, demonstrate its relationship to adjacent vascular structures, and provide real-time needle guidance during aspiration. These features may assist selection of a safer access trajectory, particularly when the collection lies close to the carotid space[7-9]. However, evidence demonstrating superior procedural success or clinical outcomes of ultrasound-guided aspiration compared with conventional or blind aspiration remains limited, and diagnostic measures such as sensitivity and specificity should not be extrapolated to therapeutic effectiveness.

In the present case, CT and POCUS served complementary roles. CT defined the full extent of the multiloculated collection and degree of airway narrowing for surgical and airway planning, whereas POCUS identified a safely accessible locule, delineated adjacent vessels with colour Doppler, and provided real-time guidance for aspiration. POCUS is rapid and dynamic but limited in assessing deep or extensive multiloculated disease, while CT provides comprehensive anatomical detail but lacks real-time procedural guidance.

Ultrasound-guided aspiration or drainage of deep-neck collections has been reported previously, including use of POCUS-guided aspiration before airway control[8] and ultrasound-assisted transoral drainage of parapharyngeal abscesses[10]. The present case differs primarily in the severity of anatomical airway compromise. A multiloculated posterior pharyngeal collection produced marked oropharyngeal narrowing and complete non-visualisation of the glottis on 70° laryngoscopy. Thus, the educational contribution lies not in the aspiration technique itself, but in its application as part of an individualised multidisciplinary airway strategy in a substantially more compromised airway[7,11]. The aspiration was not intended as definitive source control; rather, it was used as a temporary measure before definitive airway management and transoral surgical drainage.

This technique has important limitations. Because the abscess was multiloculated, aspiration most likely decompressed only the dominant or most safely accessible locule rather than achieving complete drainage. Its feasibility depends on abscess morphology, viscosity of the contents, degree of loculation, availability of a safe sonographic window, and operator expertise. Potential complications include incomplete drainage, bleeding, vascular injury, abscess rupture, aspiration, and spread of infection. Therefore, ultrasound-guided aspiration should be considered only in carefully selected patients as part of a multidisciplinary airway plan and should not replace definitive surgical drainage, antimicrobial therapy, or established difficult-airway strategies.

CONCLUSION

In conclusion, this case highlights the importance of early recognition of airway compromise and an individualised, multidisciplinary approach in the management of parapharyngeal abscesses. POCUS-guided aspiration may serve as a temporising component of airway management in selected patients with an accessible collection and severe airway narrowing. In this patient, clinical improvement following aspiration was temporally associated with subsequent successful video-laryngoscopic intubation; however, the absence of directly comparable pre- and post-intervention airway assessments prevents attribution of this outcome solely to decompression.