A patient with an infection or a collection of pus in the peritonsillar area is rather common in the ED. The process can be cellulitis or a distinct peritonsillar abscess (PTA), also called a quinsy. The infection is characterized by severe sore throat, painful swallowing, fever, drooling, tender adenopathy, muffled voice, and sometimes trismus.
It may be clinically difficult to differentiate between cellulitis and abscess initially. (“Distinguishing Peritonsillar Abscess from Cellulitis,” 2018;40:12; http://bit.ly/EMN-InFocus.) The treatment for an abscess consists of draining the pus, which can be done by needle aspiration or incision and drainage (I&D). Both interventions can be performed in the ED, but most emergency clinicians prefer to do only a needle aspiration. A formal I&D is eschewed because it is somewhat complex and more difficult. Cellulitis is treated with antibiotics, but may progress to an abscess.
The medical literature has compared clinical results from aspiration with I&D for the past 30 years, and numerous articles have attempted to determine the preferred method. The most recent comparison appeared in the Cochrane Database of Systematic Reviews to attempt, unsuccessfully, to assess the effectiveness of one compared with the other intervention.
Needle Aspiration versus Incision and Drainage for the Treatment of Peritonsillar Abscess
Cochrane Database Syst Rev
December 23, 2016; http://bit.ly/2OcaDSp
This study compared, by literature review, the effectiveness and risks of needle aspiration with I&D for treating PTA for patients age 8 and older. Numerous articles describing randomized controlled trials comparing the two procedures were analyzed. The primary outcomes were the recurrence rate, specifically those requiring repeat interventions, and any adverse effects associated with the procedure. Other outcomes included time to resumption of a normal diet, complications of the disease, and symptom scores.
Eleven studies comparing 672 participants were reviewed. Despite the numerous articles, the Cochrane Database concluded that the studies were clearly not pristine and all were at high risk for bias. Neither technique was proven superior.
All the data were considered low quality in all of the studies, but 10 studies demonstrated a somewhat higher recurrence in patients undergoing needle aspiration. Unfortunately, adverse effects, time to resumption of normal diet, and complications were inconsistently measured. In fact, only three studies reported adverse effects associated with the specific intervention. Both interventions had a good cure rate, but curiously, only one adverse effect was noted—post-procedure bleeding from I&D. Only three studies reported complications of the disease process; specifically reported were admissions to the hospital for dehydration in two patients who underwent I&D. Likewise, there was no consensus on symptom scores between the two procedures. This review concluded that it was impossible to evaluate whether needle aspiration or I&D was more effective in patients with peritonsillar abscess. No high-quality evidence drew a firm conclusion for any of the parameters studied. There was a suggestion, based on low-quality evidence, that I&D may be associated with a lower chance of recurrence compared with needle aspiration. There was also some low quality evidence that needle aspiration was less painful. Previous reviews have reached similar conclusions. (Clin Otolaryngol 2012;37:136; http://bit.ly/2OMfh97.)
Comment: I would posit that some investigator would have found a difference between the procedures, even though the evidence was poor quality, and that leads me to conclude that either intervention can be used.
It is generally accepted that ED treatment and outpatient follow-up are safe and effective in the vast majority of patients. Some physicians may be reluctant to stick a needle into the pharynx in an attempt to aspirate pus, but few complications have been reported because of this procedure, and it seems fair game for the emergency physician. The abscess is medial and slightly superior to the tonsil in the peritonsillar space, not actually in the tonsil itself.
Most abscesses resolve with ED management, but inadequately treated peritonsillar abscess carries slight risks of complications, such as airway obstruction, abscess rupture, septic necrosis of the carotid sheath, and extension of the hemorrhage into the deep tissues of the neck or posterior mediastinum. I have never seen any of these.
One may consider culturing pus from an abscess, but studies have indicated that the results of cultures obtained from PTA does not alter management, so cultures are not generally recommended. Most clinicians now use needle aspiration as the initial treatment for PTA. Re-accumulation of the PTA following an initial successful pus drainage recurs in about 10 percent of patients. Discharged patients should be seen again in 24 to 48 hours; follow-up is often easiest in the ED.
Procedure: Pain relief is vital in managing PTA. An adequate dose of an opioid, such as fentanyl or morphine intravenously, should be routine prior to manipulation or even in-depth examination. I prefer an initial 50 mcg IV dose of fentanyl, with subsequent 25 mcg doses every 10 minutes until comfort is reached. Patients should not be sedated enough that they can't respond or stay awake. Using local anesthesia with lidocaine or epinephrine injected into the peritonsillar area with a 27-gauge needle will provide nearly painless aspiration. Sprayed benzocaine can be used before lidocaine is injected, but some use only topical benzocaine as the anesthetic.
Needle aspiration can be formidable for the untrained physician, but it is safe and easy to do. The patient sits upright at eye level to the clinician. A head lamp is quite helpful. The pharynx is viewed by depressing the tongue with a tongue blade. A great view can be obtained if a lighted curved laryngoscope blade depresses the tongue. A colleague to help control the head and to retract the cheek is helpful.
Following adequate sedation or local anesthetic, choose a 10 mL syringe with an 18-gauge needle. A 10 mL syringe is required because the aspirated area is too far away for a smaller syringe. The operator takes off the needle cap, cuts off the distal third of the cap, and replaces it on the needle. That safeguard keeps the needle from going in more than a third of the length of the needle. The maximum depth should be no more than a centimeter. The needle is advanced in the midline and pointed at the abscess, not aimed laterally because the carotid artery is posterior and lateral to the tonsil. First insert it into the upper pole of the abscess. If pus is obtained, continue to drain all that is available.
Occasionally, the abscess is loculated, but most clinicians stop drainage after initial pus is obtained. If no pus is encountered, attempt aspiration in a lower aspect of the swelling. The major concern is injury to the carotid artery, but that vessel is rather deep and should not be an issue. I cannot find a single recorded carotid artery complication from needle aspiration in the literature.
Following analgesia, aspiration, observation, IV fluids, intravenous antibiotics, and a prescription for analgesics and oral antibiotics, the improved patient can be discharged with follow-up in 24 to 48 hours. About six 5 mg oxycodone pills should suffice. Patients should be appreciably improved at the first follow-up visit. Follow-up can be either in the ED or ENT office, but subsequent ENT referral is recommended for all patients.
The majority of patients can be treated as outpatients, but it is recommended to observe post-aspirated patients in the ED or observation area for three to four hours. Some relief can be rapid following the removal of pus. Overall, the hospital admission rate is about 10 percent, usually based on physician judgment and severity of illness.
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