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Contemporary management of deep infections of the neck
ADVANCES IN OMFS 1943-1993 J Oral
.. .lotac Surg
5 1'22 6·23 1. 1993
Contemporary Management of Deep Infections of the Neck LARRY J. PETERSON, DDS, MS*
In the 1943 volume of the Journal ofOral Surgery, Tichy wrote about the current status of managing deep neck infections. He reported that usual causative bacteria were Borrelia vincenti, streptococcus, staphylococcus, diplococcus, or Bacillus septicus. The primary predisposing factors leading to deep infections of the neck were local dental disease, such as dental caries and diseases ofthe gums, and lowered body resistance, which was the result of such conditions as syphilis, tuberculosis, Banti's disease, scurvy, or diabetes. The primary signs and symptoms of these infections, referred to as phlegmons, were localized pain, tenderness, redness, and edema of the overlying tissue. The treatment of phlegmons of the neck was threefold: medical, roentgenologic, and surgical. Medical treatment included rest and immediate hospitalization, saline and soapsuds enemas, forcing of fluids by mouth and hypodermoclysis, and the use of analgesics such as morphine or codeine. Hot boric acid compresses were applied to the phlegmons continuously to reduce the virulence of the infection. Sulfathiazole, 15 grains q4h, was given for 4 days. The phlegmon was also treated with radiation on three days: on the first day, 110 roentgens, on the third day, 75 roentgens, and on the fifth day, 75 roentgens. The x-rays are directed to the affected area to help soften the induration. Surgical management was delayed for 7 to 10 days. The indications for surgery were local swelling and a pitting edema of the phlegmon. When surgery was indicated, a linear incision was made in the submandibular region and blunt dissection was directed medially, superiorly, and posteriorly for approximately 4 em. This technique established excellent drainage. The incision and drainage was performed under procaine anesthesia. The patient usually recovered quickly after the incision and
drainage. This article discusses the changes in the management of deep neck infections that have occurred since 1943. Infections ofodontogenic origin may spread beyond the teeth and alveolar process into surrounding fascial spaces. The infection may then spread posteriorly, superiorly, and inferiorly into the superficial and deep temporal spaces, the masseteric space, the pterygomandibular space, and the submandibular space. The two spaces that surround the pharynx, the lateral pharyngeal space and the retropharyngeal space, when involved from odontogenic sources, are extensions ofinfections that spread from the submandibular and pterygomandibular spaces. The infections that are usually known as deep neck infections are those in the lateral pharyngeal space (also known as the parapharyngeal space) and the retropharyngeal space. I ,2 The most common cause oflateral pharyngeal space infection is the peritonsillar abscess. I ,3,4 Only approximately 20% to 30% of the lateral pharyngeal space infections are the result of odontogenic sources. Infections that involve the retropharyngeal space are classically seen in children less than 5 years 0Id,5,6 and arc generally due to otitis and pharyngitis. Lymphatic spread from these infections is to the paramedian chains of lymph nodes that receive drainage from the nasopharynx, which then suppurate, forming an abscess. These nodes atrophy at puberty, and therefore the incidence of retropharyngeal infections in adults is diminished. In the antibiotic era, while otitis and pharyngitis arc being treated with these agents, the incidence ofretropharyngeal infections in children has decreased. Consequently, the proportion of retropharyngeal infections seen in adults has increased, reaching approximately 50% currently." The incidence of retropharyngeal infections caused by odontogenic sources is approximately 5%.8 Although odontogenic infections arc unlikely to be the cause of lateral and retropharyngeal space infections, when they do occur, they can be life threatening. The purpose of this article is to discuss the pathogenesis and management of deep neck infections of odontogenic origin.
* Professor and Chairman, Department of Oral and Maxillofacial Surgery, College of Dentistry, Ohio State University, Columbus, OH. Address correspondence and reprint requests to Dr Peterson: Dcpartment of Oral and Maxillofacial Surgery, College of Dentistry, The Ohio State University, Columbus, OH 43210. © 1993 American Association of Oral and Maxillofacial Surgeons 0278-2391/93/5103-0002$3.00/0
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Pathogenesis The spread of infections from the teeth and alveolar process to the lateral and retropharyngeal spaces most commonly occurs by way of the submandibular space to the pterygomandibular space, and then to the lateral pharyngeal space. The infection can be spread to the retropharyngeal space from the lateral pharyngeal space. Lymphatic drainage from odontogenic sources directly to the retropharyngeal space rarely occurs. The microbiology ofdeep infections ofthe neck that are of odontogenic origin is similar to that found with other odontogenic infections." Deep infections of the neck are almost always polymicrobial in nature, with both aerobic and anaerobic bacteria being isolated from most patients," Typically, three or four organisms will be isolated from each infection. Most commonly, aerobic gram-positive cocci, especially Streptococcus, will be found in these patients. The anaerobic bacteria are most likely to be Peptostreptococcus, Bacteroides, and Fusobacterium. There are several minor differences between the ordinary odontogenic infection and that which is found in the cervical spaces. First of all, there appears to be a higher incidence of Fusobacterium in these severe infections.'? Fusobacterium is a very aggressive, virulent organism that causes large amounts of tissue destruction.!' A second difference is that there seems to be an increased incidence of Streptococcus milleri. Streptococcus milleri is a viridans-type Streptococcus (a-hemolytic streptococcus) that has recently been shown to have unexpected virulence and can, on its own, cause serious suppurative infections.'? The combination of Streptococcus milleri and Fusobacterium nucleatum has been noted in a number of serious lifethreatening lateral pharyngeal and retropharyngeal infcctions.'? It is tempting to suggest that a serious infection involving the deep cervical spaces will almost invariably contain these two organisms. Additionally, one must be highly suspicious that the infection will also include one of the oral Bacteroides species. All ofthese bacteria are usually sensitive to penicillin, clindamycin, metronidazole, and to selected cephalosporin antibiotics." At least 50% of Fusobacterium are resistant to erythromycin, so this antibiotic should not be used for serious odontogenic infections. Oral Bacteroides may be resistant to penicillin in approximately 15% to 25% of the cases. Therefore, penicillin remains the drug of choice for these infections. In many severe, rapidly progressive infections, it may be prudent to use combination therapy to assure maximum antimicrobial activity. Rational choices would be to use intravenous ampicillin and sulbactum (Unasyn, Roerig, New York, NY), or penicillin and metronidazole in combination. Clindamycin may also be effective. Many patients who develop deep cervical infections
will have mild to moderately compromised host defenses.P A common cause of decreased host defenses is mild to moderate diabetes. Obviously, strict control of hyperglycemia in the diabetic is critical to the successful management of these infections. Another host defense compromise associated with these infections is lymphoma."
Signs and Symptoms of Cervical Space Infections Patients who have cervical infections have a variety of characteristic signs and symptoms. 1.2.S.14 Most commonly they complain of a feeling of fever and chills, a sense of having swelling in their throat, odynophagia, dysphagia, neck pain, and neck stiffness. The typical signs of this type of infection include neck swelling, temperature greater than 38.5° centigrade, respiratory distress, sialorrhea, and trismus. If the patient has lateral pharyngeal swelling but has no trismus, the most probable diagnosis is an isolated peritonsillar abscess.' The peritonsillar abscess usually does not involve the medial pterygoid; therefore, the patient will rarely present with trismus. DIAGNOSIS
The diagnosis of a lateral a retropharyngeal space infection is usually relatively straightforward when it is the sequelae of an odontogenic infection. When these infections are caused by other sources, such as by lymphatic drainage from an otitis and pharyngitis, the diagnosis may be more difficult. The physical examination for the signs and symptoms previously mentioned is the primary method of diagnosis. An important adjunct to physical examination in making the diagnosis is the use oflateral soft tissue radiographs of the pharynx.' This radiograph can reveal a number of things th at can aide in the diagnosis ofretropharyngeal space infections. It is most important to look at the prevertebraljretropharyngeal soft-tissue shadow. In the area of the second and third cervical vertebrae, the retropharyngeal soft tissue should be less than 7 mm wide , averaging approximately 3 mm (Fig I). In the area of the sixth cervical vertebra, the soft tissue shadow is now behind the trachea and includes the thickness of the esophagus, making it approximately 14 mm wide in children and approximately 22 mm wide in the adult. Examination of this region in the lateral softtissue neck radiograph will give a good indication of the presence of a retropharyngeal infection (Figs 2 and 3). A second feature that should be looked for in this radiograph is the presence of gas. Frequently, in lateral and retropharyngeal space infections, anaerobic bacteria will produce gas that can be seen as emphysema in the soft tissues of the neck (Fig 4).
228 Finally, the lateral soft-tissue radiograph will show the curve of the cervical spine. Normally the cervical spine has a smooth, lordotic curve. However, if the patient has a retropharyngeal space infection, he or she may need to tip the head forward in the sniffingposition to maintain an open airway (Figs 2, 3, and 4). This results in a straight cervical spine or even a reversed kyphotic curve in the cervical spine. Loss of the lordotic curve is a strong indication of retropharyngeal space infection . The lateral soft-tissue radiograph is not a good view to define lateral pharyngeal space infections. A posterior-anterior view may provide some assistance in this diagnosis; however, its usefulness is limited. When a lateral pharyngeal space infection is suspected, and additional imaging information is required, the method of choice is to use a computed tomography (CT) scan of the neck (Fig 5).15 The ability of the CT scan to clearly define the lateral pharyngeal as well as the retropharyngeal space and to differentiate cellulitis from abscess is excellent. Although it is probably not necessary to do a CT scan on all patients who have odontogenic infections, when lateral and retropharyngeal space involvement is suspected, one should consider this imaging -modality.
DEEP NECK INFECTIONS
FlGURE 2. Soft tissue radiograph showing a reverse curve (kyphosis) ofthe cervical vertebra and a large preverteoral swelling. The anteroposterior dimension of the airway is maintained by the patient leaning the head forward into the sniffing position.
An important part of the diagnosis of cervical infections has to do with their progression. Whereas some infections will progress slowly, allowing adequate time to manage the patient in a variety of ways, some will progress rapidly, resulting in sudden airway obstruction and the increased possibility of mortality. Therefore, once the patient is admitted to the hospital, it is important that serial examinations be done frequently and the results recorded in the chart. Treatment
FIGURE I. Normal soft tissue radiograph of the neck. There is a smooth, lordotic curve of the cervical vertebra . The prevertebral soft tissue shadow is approximately 4 mm in the area ofC-2 and C-3 and approximately 14 mm wide in the area ofC-6 and below. The epiglottis and vallecula are visible at the base of the tongue.
The treatment of cervical space infections has three main aspects: medical management, -surgical management, and airway control. Medical management is based primarily on the administration of high doses of bacteriocidal antibiotics that are aimed at the organisms that are probably causing the infection. Ampicillin/ sulbactum, penicillin/metronidazole, clindamycin, or a cephalosporin antibiotic are generally indicted. In some of the patients who have lateral and retropharyngeal space infections of non odontogenic origin, it may be possible to treat them with antibiotics alone." The reason is that such infections may be carried to these spaces by the lymphatics and result in only an isolated space involvement. These patients generally
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degree of success.v' However, it is unlikely that multispace infections, such as those being discussed, can be successfully drained by this method. Management of the airway is the final issue in the treatment of these patients. As mentioned earlier, serial evaluations must be performed to avoid unexpected upper airway obstruction resulting in patient mortality. If the patient can be taken to the operating room in the early stages of the infection, routine intubation will usually be possible. However, if the patient has trismus or retropharyngeal swelling, other techniques of airway control may be necessary. Intubation of the awake patient using fiberoptic techniques can be very effective if performed by a skilled anesthesiologist. However, if
FIGURE 3. Radiograph showing a reverse curvature ofthe cervical spine to compensate for significant swelling at the base of the tongue. Note that the vallecula is totally obscured and that the anteroposterior diameter of the oropharynx is compromised by posterior displacement of the soft tissues.
arrive to the hospital emergency room in the very early stage oftheir infection, before actual abscess formation has occurred. Using only antibiotic treatment has been reported to be curative in approximately 50% of this type of patient. This is unlikely to be the case with cervical infections that arise secondary to odontogenic infections. The primary method of managing infections of the cervical spaces of odontogenic origin is surgical. I ,2,8, I4 Incision and drainage of all of the spaces involved, such as the submandibular, masseteric, and pterygomandibular, as well as the lateral pharyngeal and retropharyngeal spaces, should be accomplished as early as possible. Although transoral incision and drainage of the lateral pharyngeal, Pterygomandibular, and retropharyngeal spaces may be possible, it is usually preferable to drain these spaces from an extraoral approach. The incision is made in the submandibular region in the area of the angle of the mandible. If the infection has already involved the retropharyngeal space, the incision is made more vertically inclined along the anterior border of the sternocleidomastoid to allow retraction of the carotid sheath and entry into the retropharyngeal as well as the lateral pharyngeal space.' In the recent literature, an alternate surgical method for treating the isolated peritonsillar abscess has been advocated. This technique involves needle aspiration instead of open incision and drainage. The reports of this technique in the literature have indicated a high
B
FIGURE 4. A, Panoramic radiograph showing air emphysema just posterior to the ramus of the mandible on the left side. B, Lateral soft tissue radiograph of the same patient showing increased swelling in the prevertebral area as well as many areas of emphysema in the submandibular and lateral pharyngeal space region.
230
DEEP NECK INFECfIONS
can spread inferiorly to the mediastinum causing mediastinitis, pericarditis, and pneumonia.Fr'? Infections that involve the lateral pharyngeal space, which contains the carotid sheath, can cause jugular vein thrombophlebitis and carotid artery erosion with subsequent exanguination from massive hemorrhage. Although these complications are rare, when they do occur, the incidence of patient mortality increases dramatically.
Discussion
FIGURE 5. A , Horizontal Cf scan of the oropharynx showing a large lateral and medial swelling on the left side. The oropharynx is displaced significantly to the right. The central area of the medial swelling on the left represents abscess format ion (arroll'). B. Anteroposterior Cf scan showing a large med ial swelling with the central abscess formation (arroll'). Note that the oropharynx and the uvula are deviated significantly to the right.
this is not possible, surgical access to the airway through a cricothyroidectomy or a tracheostomy will be required. It is imperative to note that the most likely cause of fatality in this patient group is upper airway obstruction. Therefore, there should never be any hesitancy in establishing a surgical access.
Complications There are many complications of cervical space infections. From the retropharyngeal space, the infection
Tichy's20 description of deep infections of the neck is very similar to what we see today. However, there are several important differences. Because of the increased accuracy of the microbiologic techniques now available, anaerobic bacteria, which were relatively unknown to the surgeon of the early 1940s, are now known to play an important role in these infections. Spirochetes (Borrelia vincenti) probably have little role in the microbiology of today's cervical infections. The predisposing factors leading to infections in the 1940s were essentially the same as they arc now. Likewise, some of the conditions mentioned as causing lowered host resistance, such as diabetes, are similar to the earlier era. The biggest differences are in the management of the infection. Medical management in the early 1940s included only token use of the antimicrobial sulfathiazole. This drug had only been recently introduced in 1943, and had only limited usefulness in this type of infection. Furthermore, it was only given for 4 days. Therefore, medical management was limited mainly to the use of forced hydration, narcotics to make the patient more comfortable, and hot compresses to the area of infection. This is in marked contrast to antibiotic therapy, which we use so casually. It would be nearly impossible to consider managing a patient with an infection of the deep cervical spaces today without antibiotics. A second major change in management is the total absence of radiation therapy in the contemporary management of these infections. The rationale for radiation therapy was to produce an increase in the circulation in the area of infection. The radiation was in no way intended to actually kill bacteria. The increased circulation caused by the radiation therapy was thought to mobilize host defenses to the area of the infection. Such therapy would be soundly condemned by today's medical community. Finally, surgical management in the early 1940s was delayed rather than performed early. In today's therapy, early and aggressive incision and drainage are the standard methods of management of these infections. The earlier the patient can be taken to the operating room and managed surgically, the shorter the recovery period is likely to be. However, in 1943, surgery was delayed until the medical management with the hot compresses
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had caused the infection to localize and point. At that time, local anesthesia could be used to anesthetize the patient and incision and drainage could be performed. Interestingly, the technique for incision and drainage was essentially the same as that which would be used today. Summary
Odontogenic infections rarely lead to involvement of the lateral and retropharyngeal spaces. When this does occur, the microbiology of the infection is similar to the typical odontogenic infection, ie, Streptococcus and oral anaerobes including Peptostreptococcus, Bacteroides, and Fusobacterium. There is an increased incidence of Fusobacterium seen in the more severe infections, as well as a higher incidence of Streptococcus milleri. Many patients who have deep cervical infections also have some compromise in their host defense mechanism, such as diabetes. The signs and symptoms of deep cervical space infections are similar to those of the severe submandibular space infection, but also includes sialorrhea, respiratory distress, odynophagia, and dysphagia. Lateral soft-tissue radiographs ofthe neck are useful in assisting with the diagnosis of retropharyngeal infections, and CT scans can provide definitive information regarding lateral pharyngeal space involvement. Treatment includes the use of high-dose intravenous bacteriocidal antibiotics. The recommended antibiotics are penicillin-metronidazole, ampicillin-sulbactum, or clindamycin. Certain cephalosporins may also be useful in selected patients. Early surgical intervention is also indicated. Aggressiveincision and drainage ofall ofthe involved spaces is necessary to assure early resolution of the infection. Continual airway monitoring and the establishment of surgical airways is the final portion of the treatment triad.
References I. Dzyak WR, Zide MF: Diagnosis and treatment of lateral pharyngeal space infections. J Oral Maxillofac Surg 42:243, 1984 2. Haug RG, Picard U, Indresano AT: Diagnosis and treatment of the retropharyngeal abscess in adults. Br J Oral Maxillofac Surg 28:34, 1990 3. Spires JR, Owens JJ, Woodson GE, et al: Treatment of peritonsillar abscess.Arch OtolaryngoI Head Neck Surg 113:984, 1987 4. Herzon FS: Needle aspiration of non peritonsillar head and neck abscesses. Arch Oto1aryngol Head Neck Surg 114:1312, 1988 5. Asmar BI: Bacteriology of retropharyngeal abscess in children. Pediatr Infect Dis J 9:595, 1990 6. Hawkins DB, Austin JR: Abscesses of the neck in infants and young children. Ann Otol Rhino1 LaryngoIIOO:361, 1991 7. Gianoli GJ, Espinola TE, Guarisco JL, et al: Retropharyngeal space infection: Changing trends. Otolaryngol Head Neck Surg 105:92, 1991 8. Barratt GE, Koopmann CF, Coulthard SW: Retropharyngeal abscess-A ten-year experience. Laryngoscope 94:455, 1984 9. Peterson U: Microbiology of head and neck infections. Oral Maxillofac Surg Clin North Am 3:247, 1991 10. Heimdahl A; Non Konow L, Satoh T, et al: Clinical appearance of orofacial infections of odontogenic origin in relation to microbiological findings. J C1in MicrobioI22:299, 1985 11. Rathore MH, Barton LL, Dunkle LM: The spectrum of fusobacterial infections in children. Pediatr Infect Dis J 9:505, 1990 12. Molina JM, Leport C, Bure A, et al: Clinical and bacterial features of infections caused by streptococcus milleri. Scand J Infect Dis 23:659, 1991 13. Tabaqchali S: Anaerobic infections in the head and neck region. Scand J Infect Dis 57:24, 1988 (suppl) 14. Sethi DS, Stanley RE: Parapharyngeal abscesses.J Laryngol Otol 105:1025, 1991 15. Endicott IN, Nelson RJ, Saraceno CA: Diagnosis and management decisions in infections of the deep fascial spaces of the head and neck utilizing computerized tomography. Laryngoscope 92:630, 1982 16. Broughton RA: Nonsurgical management of deep neck infections in children. Pediatr Infect Dis J 11:14, 1992 17. Garatea-Crelgo J, Gay Escoda C: Mediastinitis from odontogenic infection. Int J Oral Maxillofac Surg 20:65, 1991 18. Musgrove BT, Malden NJ: Mediastinitis and pericarditis caused by dental infection. Br J Oral Maxillofac Surg 27:423, 1989 19. Levine TM, Wurster CF, Krespi YP: Mediastinitis occurring as a complication of odontogenic infections. Laryngoscope 96: 747, 1986 20. Tichy FS: Deep infections of the neck of dental origin. J Oral Surg 1:10, 1943
.. .lotac Surg
5 1'22 6·23 1. 1993
Contemporary Management of Deep Infections of the Neck LARRY J. PETERSON, DDS, MS*
In the 1943 volume of the Journal ofOral Surgery, Tichy wrote about the current status of managing deep neck infections. He reported that usual causative bacteria were Borrelia vincenti, streptococcus, staphylococcus, diplococcus, or Bacillus septicus. The primary predisposing factors leading to deep infections of the neck were local dental disease, such as dental caries and diseases ofthe gums, and lowered body resistance, which was the result of such conditions as syphilis, tuberculosis, Banti's disease, scurvy, or diabetes. The primary signs and symptoms of these infections, referred to as phlegmons, were localized pain, tenderness, redness, and edema of the overlying tissue. The treatment of phlegmons of the neck was threefold: medical, roentgenologic, and surgical. Medical treatment included rest and immediate hospitalization, saline and soapsuds enemas, forcing of fluids by mouth and hypodermoclysis, and the use of analgesics such as morphine or codeine. Hot boric acid compresses were applied to the phlegmons continuously to reduce the virulence of the infection. Sulfathiazole, 15 grains q4h, was given for 4 days. The phlegmon was also treated with radiation on three days: on the first day, 110 roentgens, on the third day, 75 roentgens, and on the fifth day, 75 roentgens. The x-rays are directed to the affected area to help soften the induration. Surgical management was delayed for 7 to 10 days. The indications for surgery were local swelling and a pitting edema of the phlegmon. When surgery was indicated, a linear incision was made in the submandibular region and blunt dissection was directed medially, superiorly, and posteriorly for approximately 4 em. This technique established excellent drainage. The incision and drainage was performed under procaine anesthesia. The patient usually recovered quickly after the incision and
drainage. This article discusses the changes in the management of deep neck infections that have occurred since 1943. Infections ofodontogenic origin may spread beyond the teeth and alveolar process into surrounding fascial spaces. The infection may then spread posteriorly, superiorly, and inferiorly into the superficial and deep temporal spaces, the masseteric space, the pterygomandibular space, and the submandibular space. The two spaces that surround the pharynx, the lateral pharyngeal space and the retropharyngeal space, when involved from odontogenic sources, are extensions ofinfections that spread from the submandibular and pterygomandibular spaces. The infections that are usually known as deep neck infections are those in the lateral pharyngeal space (also known as the parapharyngeal space) and the retropharyngeal space. I ,2 The most common cause oflateral pharyngeal space infection is the peritonsillar abscess. I ,3,4 Only approximately 20% to 30% of the lateral pharyngeal space infections are the result of odontogenic sources. Infections that involve the retropharyngeal space are classically seen in children less than 5 years 0Id,5,6 and arc generally due to otitis and pharyngitis. Lymphatic spread from these infections is to the paramedian chains of lymph nodes that receive drainage from the nasopharynx, which then suppurate, forming an abscess. These nodes atrophy at puberty, and therefore the incidence of retropharyngeal infections in adults is diminished. In the antibiotic era, while otitis and pharyngitis arc being treated with these agents, the incidence ofretropharyngeal infections in children has decreased. Consequently, the proportion of retropharyngeal infections seen in adults has increased, reaching approximately 50% currently." The incidence of retropharyngeal infections caused by odontogenic sources is approximately 5%.8 Although odontogenic infections arc unlikely to be the cause of lateral and retropharyngeal space infections, when they do occur, they can be life threatening. The purpose of this article is to discuss the pathogenesis and management of deep neck infections of odontogenic origin.
* Professor and Chairman, Department of Oral and Maxillofacial Surgery, College of Dentistry, Ohio State University, Columbus, OH. Address correspondence and reprint requests to Dr Peterson: Dcpartment of Oral and Maxillofacial Surgery, College of Dentistry, The Ohio State University, Columbus, OH 43210. © 1993 American Association of Oral and Maxillofacial Surgeons 0278-2391/93/5103-0002$3.00/0
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Pathogenesis The spread of infections from the teeth and alveolar process to the lateral and retropharyngeal spaces most commonly occurs by way of the submandibular space to the pterygomandibular space, and then to the lateral pharyngeal space. The infection can be spread to the retropharyngeal space from the lateral pharyngeal space. Lymphatic drainage from odontogenic sources directly to the retropharyngeal space rarely occurs. The microbiology ofdeep infections ofthe neck that are of odontogenic origin is similar to that found with other odontogenic infections." Deep infections of the neck are almost always polymicrobial in nature, with both aerobic and anaerobic bacteria being isolated from most patients," Typically, three or four organisms will be isolated from each infection. Most commonly, aerobic gram-positive cocci, especially Streptococcus, will be found in these patients. The anaerobic bacteria are most likely to be Peptostreptococcus, Bacteroides, and Fusobacterium. There are several minor differences between the ordinary odontogenic infection and that which is found in the cervical spaces. First of all, there appears to be a higher incidence of Fusobacterium in these severe infections.'? Fusobacterium is a very aggressive, virulent organism that causes large amounts of tissue destruction.!' A second difference is that there seems to be an increased incidence of Streptococcus milleri. Streptococcus milleri is a viridans-type Streptococcus (a-hemolytic streptococcus) that has recently been shown to have unexpected virulence and can, on its own, cause serious suppurative infections.'? The combination of Streptococcus milleri and Fusobacterium nucleatum has been noted in a number of serious lifethreatening lateral pharyngeal and retropharyngeal infcctions.'? It is tempting to suggest that a serious infection involving the deep cervical spaces will almost invariably contain these two organisms. Additionally, one must be highly suspicious that the infection will also include one of the oral Bacteroides species. All ofthese bacteria are usually sensitive to penicillin, clindamycin, metronidazole, and to selected cephalosporin antibiotics." At least 50% of Fusobacterium are resistant to erythromycin, so this antibiotic should not be used for serious odontogenic infections. Oral Bacteroides may be resistant to penicillin in approximately 15% to 25% of the cases. Therefore, penicillin remains the drug of choice for these infections. In many severe, rapidly progressive infections, it may be prudent to use combination therapy to assure maximum antimicrobial activity. Rational choices would be to use intravenous ampicillin and sulbactum (Unasyn, Roerig, New York, NY), or penicillin and metronidazole in combination. Clindamycin may also be effective. Many patients who develop deep cervical infections
will have mild to moderately compromised host defenses.P A common cause of decreased host defenses is mild to moderate diabetes. Obviously, strict control of hyperglycemia in the diabetic is critical to the successful management of these infections. Another host defense compromise associated with these infections is lymphoma."
Signs and Symptoms of Cervical Space Infections Patients who have cervical infections have a variety of characteristic signs and symptoms. 1.2.S.14 Most commonly they complain of a feeling of fever and chills, a sense of having swelling in their throat, odynophagia, dysphagia, neck pain, and neck stiffness. The typical signs of this type of infection include neck swelling, temperature greater than 38.5° centigrade, respiratory distress, sialorrhea, and trismus. If the patient has lateral pharyngeal swelling but has no trismus, the most probable diagnosis is an isolated peritonsillar abscess.' The peritonsillar abscess usually does not involve the medial pterygoid; therefore, the patient will rarely present with trismus. DIAGNOSIS
The diagnosis of a lateral a retropharyngeal space infection is usually relatively straightforward when it is the sequelae of an odontogenic infection. When these infections are caused by other sources, such as by lymphatic drainage from an otitis and pharyngitis, the diagnosis may be more difficult. The physical examination for the signs and symptoms previously mentioned is the primary method of diagnosis. An important adjunct to physical examination in making the diagnosis is the use oflateral soft tissue radiographs of the pharynx.' This radiograph can reveal a number of things th at can aide in the diagnosis ofretropharyngeal space infections. It is most important to look at the prevertebraljretropharyngeal soft-tissue shadow. In the area of the second and third cervical vertebrae, the retropharyngeal soft tissue should be less than 7 mm wide , averaging approximately 3 mm (Fig I). In the area of the sixth cervical vertebra, the soft tissue shadow is now behind the trachea and includes the thickness of the esophagus, making it approximately 14 mm wide in children and approximately 22 mm wide in the adult. Examination of this region in the lateral softtissue neck radiograph will give a good indication of the presence of a retropharyngeal infection (Figs 2 and 3). A second feature that should be looked for in this radiograph is the presence of gas. Frequently, in lateral and retropharyngeal space infections, anaerobic bacteria will produce gas that can be seen as emphysema in the soft tissues of the neck (Fig 4).
228 Finally, the lateral soft-tissue radiograph will show the curve of the cervical spine. Normally the cervical spine has a smooth, lordotic curve. However, if the patient has a retropharyngeal space infection, he or she may need to tip the head forward in the sniffingposition to maintain an open airway (Figs 2, 3, and 4). This results in a straight cervical spine or even a reversed kyphotic curve in the cervical spine. Loss of the lordotic curve is a strong indication of retropharyngeal space infection . The lateral soft-tissue radiograph is not a good view to define lateral pharyngeal space infections. A posterior-anterior view may provide some assistance in this diagnosis; however, its usefulness is limited. When a lateral pharyngeal space infection is suspected, and additional imaging information is required, the method of choice is to use a computed tomography (CT) scan of the neck (Fig 5).15 The ability of the CT scan to clearly define the lateral pharyngeal as well as the retropharyngeal space and to differentiate cellulitis from abscess is excellent. Although it is probably not necessary to do a CT scan on all patients who have odontogenic infections, when lateral and retropharyngeal space involvement is suspected, one should consider this imaging -modality.
DEEP NECK INFECTIONS
FlGURE 2. Soft tissue radiograph showing a reverse curve (kyphosis) ofthe cervical vertebra and a large preverteoral swelling. The anteroposterior dimension of the airway is maintained by the patient leaning the head forward into the sniffing position.
An important part of the diagnosis of cervical infections has to do with their progression. Whereas some infections will progress slowly, allowing adequate time to manage the patient in a variety of ways, some will progress rapidly, resulting in sudden airway obstruction and the increased possibility of mortality. Therefore, once the patient is admitted to the hospital, it is important that serial examinations be done frequently and the results recorded in the chart. Treatment
FIGURE I. Normal soft tissue radiograph of the neck. There is a smooth, lordotic curve of the cervical vertebra . The prevertebral soft tissue shadow is approximately 4 mm in the area ofC-2 and C-3 and approximately 14 mm wide in the area ofC-6 and below. The epiglottis and vallecula are visible at the base of the tongue.
The treatment of cervical space infections has three main aspects: medical management, -surgical management, and airway control. Medical management is based primarily on the administration of high doses of bacteriocidal antibiotics that are aimed at the organisms that are probably causing the infection. Ampicillin/ sulbactum, penicillin/metronidazole, clindamycin, or a cephalosporin antibiotic are generally indicted. In some of the patients who have lateral and retropharyngeal space infections of non odontogenic origin, it may be possible to treat them with antibiotics alone." The reason is that such infections may be carried to these spaces by the lymphatics and result in only an isolated space involvement. These patients generally
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degree of success.v' However, it is unlikely that multispace infections, such as those being discussed, can be successfully drained by this method. Management of the airway is the final issue in the treatment of these patients. As mentioned earlier, serial evaluations must be performed to avoid unexpected upper airway obstruction resulting in patient mortality. If the patient can be taken to the operating room in the early stages of the infection, routine intubation will usually be possible. However, if the patient has trismus or retropharyngeal swelling, other techniques of airway control may be necessary. Intubation of the awake patient using fiberoptic techniques can be very effective if performed by a skilled anesthesiologist. However, if
FIGURE 3. Radiograph showing a reverse curvature ofthe cervical spine to compensate for significant swelling at the base of the tongue. Note that the vallecula is totally obscured and that the anteroposterior diameter of the oropharynx is compromised by posterior displacement of the soft tissues.
arrive to the hospital emergency room in the very early stage oftheir infection, before actual abscess formation has occurred. Using only antibiotic treatment has been reported to be curative in approximately 50% of this type of patient. This is unlikely to be the case with cervical infections that arise secondary to odontogenic infections. The primary method of managing infections of the cervical spaces of odontogenic origin is surgical. I ,2,8, I4 Incision and drainage of all of the spaces involved, such as the submandibular, masseteric, and pterygomandibular, as well as the lateral pharyngeal and retropharyngeal spaces, should be accomplished as early as possible. Although transoral incision and drainage of the lateral pharyngeal, Pterygomandibular, and retropharyngeal spaces may be possible, it is usually preferable to drain these spaces from an extraoral approach. The incision is made in the submandibular region in the area of the angle of the mandible. If the infection has already involved the retropharyngeal space, the incision is made more vertically inclined along the anterior border of the sternocleidomastoid to allow retraction of the carotid sheath and entry into the retropharyngeal as well as the lateral pharyngeal space.' In the recent literature, an alternate surgical method for treating the isolated peritonsillar abscess has been advocated. This technique involves needle aspiration instead of open incision and drainage. The reports of this technique in the literature have indicated a high
B
FIGURE 4. A, Panoramic radiograph showing air emphysema just posterior to the ramus of the mandible on the left side. B, Lateral soft tissue radiograph of the same patient showing increased swelling in the prevertebral area as well as many areas of emphysema in the submandibular and lateral pharyngeal space region.
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can spread inferiorly to the mediastinum causing mediastinitis, pericarditis, and pneumonia.Fr'? Infections that involve the lateral pharyngeal space, which contains the carotid sheath, can cause jugular vein thrombophlebitis and carotid artery erosion with subsequent exanguination from massive hemorrhage. Although these complications are rare, when they do occur, the incidence of patient mortality increases dramatically.
Discussion
FIGURE 5. A , Horizontal Cf scan of the oropharynx showing a large lateral and medial swelling on the left side. The oropharynx is displaced significantly to the right. The central area of the medial swelling on the left represents abscess format ion (arroll'). B. Anteroposterior Cf scan showing a large med ial swelling with the central abscess formation (arroll'). Note that the oropharynx and the uvula are deviated significantly to the right.
this is not possible, surgical access to the airway through a cricothyroidectomy or a tracheostomy will be required. It is imperative to note that the most likely cause of fatality in this patient group is upper airway obstruction. Therefore, there should never be any hesitancy in establishing a surgical access.
Complications There are many complications of cervical space infections. From the retropharyngeal space, the infection
Tichy's20 description of deep infections of the neck is very similar to what we see today. However, there are several important differences. Because of the increased accuracy of the microbiologic techniques now available, anaerobic bacteria, which were relatively unknown to the surgeon of the early 1940s, are now known to play an important role in these infections. Spirochetes (Borrelia vincenti) probably have little role in the microbiology of today's cervical infections. The predisposing factors leading to infections in the 1940s were essentially the same as they arc now. Likewise, some of the conditions mentioned as causing lowered host resistance, such as diabetes, are similar to the earlier era. The biggest differences are in the management of the infection. Medical management in the early 1940s included only token use of the antimicrobial sulfathiazole. This drug had only been recently introduced in 1943, and had only limited usefulness in this type of infection. Furthermore, it was only given for 4 days. Therefore, medical management was limited mainly to the use of forced hydration, narcotics to make the patient more comfortable, and hot compresses to the area of infection. This is in marked contrast to antibiotic therapy, which we use so casually. It would be nearly impossible to consider managing a patient with an infection of the deep cervical spaces today without antibiotics. A second major change in management is the total absence of radiation therapy in the contemporary management of these infections. The rationale for radiation therapy was to produce an increase in the circulation in the area of infection. The radiation was in no way intended to actually kill bacteria. The increased circulation caused by the radiation therapy was thought to mobilize host defenses to the area of the infection. Such therapy would be soundly condemned by today's medical community. Finally, surgical management in the early 1940s was delayed rather than performed early. In today's therapy, early and aggressive incision and drainage are the standard methods of management of these infections. The earlier the patient can be taken to the operating room and managed surgically, the shorter the recovery period is likely to be. However, in 1943, surgery was delayed until the medical management with the hot compresses
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had caused the infection to localize and point. At that time, local anesthesia could be used to anesthetize the patient and incision and drainage could be performed. Interestingly, the technique for incision and drainage was essentially the same as that which would be used today. Summary
Odontogenic infections rarely lead to involvement of the lateral and retropharyngeal spaces. When this does occur, the microbiology of the infection is similar to the typical odontogenic infection, ie, Streptococcus and oral anaerobes including Peptostreptococcus, Bacteroides, and Fusobacterium. There is an increased incidence of Fusobacterium seen in the more severe infections, as well as a higher incidence of Streptococcus milleri. Many patients who have deep cervical infections also have some compromise in their host defense mechanism, such as diabetes. The signs and symptoms of deep cervical space infections are similar to those of the severe submandibular space infection, but also includes sialorrhea, respiratory distress, odynophagia, and dysphagia. Lateral soft-tissue radiographs ofthe neck are useful in assisting with the diagnosis of retropharyngeal infections, and CT scans can provide definitive information regarding lateral pharyngeal space involvement. Treatment includes the use of high-dose intravenous bacteriocidal antibiotics. The recommended antibiotics are penicillin-metronidazole, ampicillin-sulbactum, or clindamycin. Certain cephalosporins may also be useful in selected patients. Early surgical intervention is also indicated. Aggressiveincision and drainage ofall ofthe involved spaces is necessary to assure early resolution of the infection. Continual airway monitoring and the establishment of surgical airways is the final portion of the treatment triad.
References I. Dzyak WR, Zide MF: Diagnosis and treatment of lateral pharyngeal space infections. J Oral Maxillofac Surg 42:243, 1984 2. Haug RG, Picard U, Indresano AT: Diagnosis and treatment of the retropharyngeal abscess in adults. Br J Oral Maxillofac Surg 28:34, 1990 3. Spires JR, Owens JJ, Woodson GE, et al: Treatment of peritonsillar abscess.Arch OtolaryngoI Head Neck Surg 113:984, 1987 4. Herzon FS: Needle aspiration of non peritonsillar head and neck abscesses. Arch Oto1aryngol Head Neck Surg 114:1312, 1988 5. Asmar BI: Bacteriology of retropharyngeal abscess in children. Pediatr Infect Dis J 9:595, 1990 6. Hawkins DB, Austin JR: Abscesses of the neck in infants and young children. Ann Otol Rhino1 LaryngoIIOO:361, 1991 7. Gianoli GJ, Espinola TE, Guarisco JL, et al: Retropharyngeal space infection: Changing trends. Otolaryngol Head Neck Surg 105:92, 1991 8. Barratt GE, Koopmann CF, Coulthard SW: Retropharyngeal abscess-A ten-year experience. Laryngoscope 94:455, 1984 9. Peterson U: Microbiology of head and neck infections. Oral Maxillofac Surg Clin North Am 3:247, 1991 10. Heimdahl A; Non Konow L, Satoh T, et al: Clinical appearance of orofacial infections of odontogenic origin in relation to microbiological findings. J C1in MicrobioI22:299, 1985 11. Rathore MH, Barton LL, Dunkle LM: The spectrum of fusobacterial infections in children. Pediatr Infect Dis J 9:505, 1990 12. Molina JM, Leport C, Bure A, et al: Clinical and bacterial features of infections caused by streptococcus milleri. Scand J Infect Dis 23:659, 1991 13. Tabaqchali S: Anaerobic infections in the head and neck region. Scand J Infect Dis 57:24, 1988 (suppl) 14. Sethi DS, Stanley RE: Parapharyngeal abscesses.J Laryngol Otol 105:1025, 1991 15. Endicott IN, Nelson RJ, Saraceno CA: Diagnosis and management decisions in infections of the deep fascial spaces of the head and neck utilizing computerized tomography. Laryngoscope 92:630, 1982 16. Broughton RA: Nonsurgical management of deep neck infections in children. Pediatr Infect Dis J 11:14, 1992 17. Garatea-Crelgo J, Gay Escoda C: Mediastinitis from odontogenic infection. Int J Oral Maxillofac Surg 20:65, 1991 18. Musgrove BT, Malden NJ: Mediastinitis and pericarditis caused by dental infection. Br J Oral Maxillofac Surg 27:423, 1989 19. Levine TM, Wurster CF, Krespi YP: Mediastinitis occurring as a complication of odontogenic infections. Laryngoscope 96: 747, 1986 20. Tichy FS: Deep infections of the neck of dental origin. J Oral Surg 1:10, 1943