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Retropharyngeal Phlegmon in a Hemodialysis Patient with Staphylococcus Aureus Bacteremia
The Journal of Emergency Medicine, Vol. 35, No. 2, pp. 163–165, 2008 Copyright © 2008 Elsevier Inc. Printed in the USA. All rights reserved 0736-4679/08 $–see front matter
doi:10.1016/j.jemermed.2007.07.072
Clinical Communications: Adults
RETROPHARYNGEAL PHLEGMON IN A HEMODIALYSIS PATIENT WITH STAPHYLOCOCCUS AUREUS BACTEREMIA Richard I. Lappin,
MD, PHD*
and Jeffrey Silberzweig,
MD†‡§
*Department of Emergency Medicine, New York-Presbyterian Hospital/Weill Cornell Medical Center, New York, New York, †Rogosin Institute Manhattan Dialysis Center, New York, New York, ‡Rogosin Institute Queens Dialysis Center, Woodside, New York, and §Division of Nephrology, New York-Presbyterian Hospital/Weill Cornell Medical Center, New York, New York Reprint Address: Richard I. Lappin, MD, PHD, Department of Emergency Medicine, New York-Presbyterian Hospital, 525 East 68th Street, New York, NY 10021
e Abstract—Staphylococcus aureus bacteremia is a frequent occurrence in patients with indwelling catheters. Endocarditis, osteomyelitis, and septic arthritis are common metastatic complications. A hemodialysis patient developed fever, headache, neck pain, sore throat, and dysphagia in the setting of S. aureus bacteremia. Contrast computed tomography scan of the neck revealed a retropharyngeal phlegmon. Recurrent bacteremia led to the identification of the access graft as the infectious source. We present this case to increase awareness among emergency physicians that retropharyngeal infection by S. aureus can arise by hematogenous spread and should be considered in the differential diagnosis of a bacteremic patient with sore throat or neck pain. © 2008 Elsevier Inc.
sites such as heart valves, joints, vertebrae, and the central nervous system (1). A patient with S. aureus bacteremia who presents to the ED with headache or stiff neck raises the urgent possibility of bacterial meningitis. Once meningitis is excluded, cervical vertebral osteomyelitis and epidural abscess remain important, though less immediately lifethreatening, potential diagnoses. Although infections of the deep soft tissues of the neck can cause these same symptoms, such infections are generally considered to be the result of trauma to the pharynx or esophagus, not bacteremic seeding. We report a rare case of a patient who developed a retropharyngeal phlegmon by hematogenous seeding from an infected dialysis access graft.
e Keywords—Staphylococcus aureus; bacteremia; retropharyngeal phlegmon; hemodialysis
CASE REPORT INTRODUCTION
A 59-year-old man was sent to the ED from his hemodialysis facility complaining of headache and sore throat. He had a history of renal failure secondary to polycystic kidney disease, and had resumed hemodialysis after a failed renal transplant. His medical history also included prostate cancer for which he was receiving radiation therapy, hypertension, and Kaposi’s sarcoma. He was human immunodeficiency virus negative. Two months before presentation he had developed methicillin-sensitive Staphylococcus aureus (MSSA) bac-
As the number of Americans receiving chemotherapy and hemodialysis rises, emergency departments (EDs) are seeing increasing numbers of patients presenting with complications of indwelling vascular catheters. Staphylococcus aureus is one of the most common agents in catheter infection, often leading to bacteremia. Once it is circulating in the bloodstream, S. aureus has a remarkable ability to colonize distant
RECEIVED: 1 May 2006; ACCEPTED: 31 July 2007 163
164
R. I. Lappin and J. Silberzweig
Figure 1. Contrast CT scan of the neck. Axial (left) and reconstructed sagittal (right) images showing marked prevertebral soft-tissue swelling (arrows).
teremia without an obvious source. A transthoracic echocardiogram showed no valve vegetations, and he received 2 weeks of intravenous antibiotics as an inpatient. About a week after discharge he began to notice a mild sore throat and a sense that food got stuck at mid-neck level when he swallowed. He was now careful to cut his food into small pieces. One week before presentation he developed fevers, chills, headache, stiff neck, sore throat, and hoarseness. Blood cultures were drawn at the dialysis unit when his fevers first began and, according to the report sent with the patient, they were positive for “Pseudomonas sensitive to vancomycin.” He had received vancomycin with his last two dialysis sessions. In the ED his temperature was 38.5°C (101.3°F), pulse 114 beats/min, and blood pressure 140/85 mm Hg. He was awake, alert, fully oriented and lucid. The oropharynx was unremarkable on visual inspection. The back of the neck was tender in the upper midline. The neck was not actually stiff, but it was painful for him to flex or rotate fully. He had a loud systolic murmur at the right upper sternal border. The access graft in the right upper arm had no signs of infection. A complete blood count showed a white blood cell count of 9300 /mL, with 83% polymorphonuclear leukocytes and no band forms. The clinical impression was possible vertebral osteomyelitis or epidural abscess. The absence of true meningeal signs, along with symptoms of odynophagia and dysphagia, were felt to adequately exclude meningitis on clinical grounds without the need for lumbar puncture. Intravenous vancomycin and gentamicin were given. An Ear, Nose, and Throat consultant found no physical signs of neck infection. Contrast computed
tomography (CT) scan of the neck (Figure 1) revealed marked prevertebral soft-tissue edema, consistent with a retropharyngeal-space phlegmon. There was no rim enhancement suggestive of an abscess, and no evidence of osteomyelitis or discitis. Magnetic resonance imaging (MRI) of the neck several days later confirmed these findings. Blood cultures grew MSSA and methicillin-resistant S. aureus (MRSA). The inpatient team was able to retrieve the official reports of his outpatient blood cultures, which had grown MSSA, not Pseudomonas. Transesophageal echocardiography showed no valve vegetations. He was discharged on hospital day 9 when his pain and fever had resolved, with a plan to receive vancomycin and gentamicin at dialysis. One week later he was readmitted to the hospital complaining of fatigue, generalized weakness, and liquid, bloody diarrhea. Colonoscopy showed blood oozing from ectatic rectal vessels, consistent with radiation proctitis. A stool sample was positive for Clostridium dificile toxin. On hospital day 3, he was febrile to 38.9°C (102°F). A blood culture sent on admission grew MSSA. There was now concern that the access graft was infected. An indium-labeled leukocyte scan showed focal uptake at the site of the graft in the right upper arm. He was taken to the operating room to have the graft excised. At operation, the graft was found to be surrounded by pus, and the lumen filled with pus and thrombus. Cultures of the graft grew MRSA. He was discharged on day 11 with a new subclavian hemodialysis catheter and a plan to continue vancomycin and gentamicin for a total of 6 weeks.
Retropharyngeal Phlegmon
DISCUSSION S. aureus is the leading cause of bacteremia in patients receiving hemodialysis, and a major cause of death from sepsis in this population. Most S. aureus bacteremia arises from infections at the access site; conversely, about 75% of access site infections are caused by S. aureus. The risk of bacteremia is higher for polytetrafluoroethylene grafts than for fistulas, and highest for indwelling central venous catheters. Infection of the access site may be clinically silent or associated with only subtle clinical signs such as slight warmth over the graft. Often, clotting of the access is the only sign of an occult infection. In other cases, access site infection becomes apparent only when—as in this case—the patient develops metastatic foci of infection such as endocarditis, septic pulmonary emboli, septic arthritis, or osteomyelitis (2). Hematogenous infection of heart valves, vertebrae, and joints by S. aureus in patients with intravascular catheters has been widely reported. In contrast, we have found only two reports in the recent English-language literature of retropharyngeal soft-tissue infection caused by hematogenous seeding in the setting of S. aureus bacteremia (3,4). One of those patients, described by Hughes et al., was receiving hemodialysis (3). In children, retropharyngeal infections usually arise from infectious foci in adjacent structures such as the mandibular teeth, tonsils, paranasal sinuses, middle ear, parotid gland, and deep cervical lymph nodes. In adults, retropharyngeal infections sometimes arise from a dental or peritonsillar abscess, but are most often a complication of penetrating trauma to the pharynx or esophagus, for example, from endoscopy or a swallowed foreign body such as a chicken bone. They are typically polymicrobial infections with flora derived from the adjacent mucosa, including Streptococcus viridans, Streptococcus pyogenes, Bacteroides and other oral anaerobes, S. aureus, Klebsiella, and Pseudomonas (5). Although intravenous drug abuse is recognized as a risk factor for the development of deep neck abscesses, these infections are generally attributed to injections directly into the deep veins of the neck itself (“shotgunning”) (6,7). Three retropharyngeal “potential spaces” lie between the hypopharynx and the vertebrae. The immediate retropharyngeal space is located between the constrictor muscles of the hypopharynx and the deep layer of cervical fascia. Behind it lies the so-called “danger space,” located between the deep fascia and the prevertebral fascia; this space descends into the mediastinum. Behind this is the prevertebral space, which lies between the prevertebral fascia and the vertebrae; this space extends caudally to the coccyx (8). Due to the caudal extension of
165
these spaces, deep neck infections can lead to mediastinitis and even psoas abscess. In this case it was not possible, even with high-resolution CT and MRI, to determine which of the closely apposed retropharyngeal spaces was the center of infection. The symptoms of retropharyngeal space infection can include sore throat, odynophagia, dysphagia, neck pain, and trismus. Examination may reveal neck erythema, swelling, doughy consistency, pitting edema, or lymphadenopathy (5). However, retropharyngeal infections are often difficult to diagnose clinically, and can be easily confused with pharyngitis, epiglottitis, cervical osteomyelitis, or meningitis. Prevertebral soft-tissue swelling on lateral neck X-ray study is suggestive; CT scan and MRI provide more specific anatomic information and can differentiate between a cellulitis or phlegmon, which can be treated with intravenous antibiotics, and an abscess that may require surgical drainage (9).
CONCLUSIONS We report this case to raise awareness among emergency physicians of the possibility of retropharyngeal infection in a patient with S. aureus bacteremia who complains of sore throat or neck pain. This infection can arise by hematogenous spread from a distant site. In a hemodialysis patient, the dialysis access graft or catheter should be evaluated as a potential source of unexplained bacteremia, even when clinical signs of access site infection are absent.
REFERENCES 1. Mitchell DH, Howden BP. Diagnosis and management of staphylococcus aureus bacteremia. Intern Med J 2005;35(Suppl 2): S17–24. 2. Marr KA. Staphylococcus aureus bacteremia in patients undergoing hemodialysis. Semin Dial 2000;13:23–9. 3. Hughes J, Martin RJ, Clutterbuck EJ. Retropharyngeal infection with Staphylococcus aureus in a haemodialysis patient. Am J Nephrol 1993;13:435– 6. 4. Sato K, Izumi T, Toshima M, et al. Retropharyngeal abscess due to methicillin-resistant Staphylococcus aureus in a case of acute myeloid leukemia. Intern Med 2005;44:346 –9. 5. Chow AW. Life-threatening infections of the head, neck, and upper respiratory tract. In: Hall JB, Schmidt GA, Wood LD, eds. Principles of critical care. New York: McGraw-Hill; 1998:887–902. 6. Har-El G, Aroesty JH, Shaha A, Lucente FE. Changing trends in deep neck abscess. Oral Surg Oral Med Oral Pathol 1994;77: 446 –50. 7. Parhiscar A, Har-El G. Deep neck abscess: a retrospective review of 210 cases. Ann Otol Rhinol Laryngol 2001;110:1051– 4. 8. Barratt GE, Koopman CF, Coulthard SW. Retropharyngeal abscess—a ten-year experience. Laryngoscope 1984;94:455– 63. 9. Gidley PW, Ghorayeb BY, Stiernberg CM. Contemporary management of deep neck space infections. Otolaryngol Head Neck Surg 1997;116:16 –22.
doi:10.1016/j.jemermed.2007.07.072
Clinical Communications: Adults
RETROPHARYNGEAL PHLEGMON IN A HEMODIALYSIS PATIENT WITH STAPHYLOCOCCUS AUREUS BACTEREMIA Richard I. Lappin,
MD, PHD*
and Jeffrey Silberzweig,
MD†‡§
*Department of Emergency Medicine, New York-Presbyterian Hospital/Weill Cornell Medical Center, New York, New York, †Rogosin Institute Manhattan Dialysis Center, New York, New York, ‡Rogosin Institute Queens Dialysis Center, Woodside, New York, and §Division of Nephrology, New York-Presbyterian Hospital/Weill Cornell Medical Center, New York, New York Reprint Address: Richard I. Lappin, MD, PHD, Department of Emergency Medicine, New York-Presbyterian Hospital, 525 East 68th Street, New York, NY 10021
e Abstract—Staphylococcus aureus bacteremia is a frequent occurrence in patients with indwelling catheters. Endocarditis, osteomyelitis, and septic arthritis are common metastatic complications. A hemodialysis patient developed fever, headache, neck pain, sore throat, and dysphagia in the setting of S. aureus bacteremia. Contrast computed tomography scan of the neck revealed a retropharyngeal phlegmon. Recurrent bacteremia led to the identification of the access graft as the infectious source. We present this case to increase awareness among emergency physicians that retropharyngeal infection by S. aureus can arise by hematogenous spread and should be considered in the differential diagnosis of a bacteremic patient with sore throat or neck pain. © 2008 Elsevier Inc.
sites such as heart valves, joints, vertebrae, and the central nervous system (1). A patient with S. aureus bacteremia who presents to the ED with headache or stiff neck raises the urgent possibility of bacterial meningitis. Once meningitis is excluded, cervical vertebral osteomyelitis and epidural abscess remain important, though less immediately lifethreatening, potential diagnoses. Although infections of the deep soft tissues of the neck can cause these same symptoms, such infections are generally considered to be the result of trauma to the pharynx or esophagus, not bacteremic seeding. We report a rare case of a patient who developed a retropharyngeal phlegmon by hematogenous seeding from an infected dialysis access graft.
e Keywords—Staphylococcus aureus; bacteremia; retropharyngeal phlegmon; hemodialysis
CASE REPORT INTRODUCTION
A 59-year-old man was sent to the ED from his hemodialysis facility complaining of headache and sore throat. He had a history of renal failure secondary to polycystic kidney disease, and had resumed hemodialysis after a failed renal transplant. His medical history also included prostate cancer for which he was receiving radiation therapy, hypertension, and Kaposi’s sarcoma. He was human immunodeficiency virus negative. Two months before presentation he had developed methicillin-sensitive Staphylococcus aureus (MSSA) bac-
As the number of Americans receiving chemotherapy and hemodialysis rises, emergency departments (EDs) are seeing increasing numbers of patients presenting with complications of indwelling vascular catheters. Staphylococcus aureus is one of the most common agents in catheter infection, often leading to bacteremia. Once it is circulating in the bloodstream, S. aureus has a remarkable ability to colonize distant
RECEIVED: 1 May 2006; ACCEPTED: 31 July 2007 163
164
R. I. Lappin and J. Silberzweig
Figure 1. Contrast CT scan of the neck. Axial (left) and reconstructed sagittal (right) images showing marked prevertebral soft-tissue swelling (arrows).
teremia without an obvious source. A transthoracic echocardiogram showed no valve vegetations, and he received 2 weeks of intravenous antibiotics as an inpatient. About a week after discharge he began to notice a mild sore throat and a sense that food got stuck at mid-neck level when he swallowed. He was now careful to cut his food into small pieces. One week before presentation he developed fevers, chills, headache, stiff neck, sore throat, and hoarseness. Blood cultures were drawn at the dialysis unit when his fevers first began and, according to the report sent with the patient, they were positive for “Pseudomonas sensitive to vancomycin.” He had received vancomycin with his last two dialysis sessions. In the ED his temperature was 38.5°C (101.3°F), pulse 114 beats/min, and blood pressure 140/85 mm Hg. He was awake, alert, fully oriented and lucid. The oropharynx was unremarkable on visual inspection. The back of the neck was tender in the upper midline. The neck was not actually stiff, but it was painful for him to flex or rotate fully. He had a loud systolic murmur at the right upper sternal border. The access graft in the right upper arm had no signs of infection. A complete blood count showed a white blood cell count of 9300 /mL, with 83% polymorphonuclear leukocytes and no band forms. The clinical impression was possible vertebral osteomyelitis or epidural abscess. The absence of true meningeal signs, along with symptoms of odynophagia and dysphagia, were felt to adequately exclude meningitis on clinical grounds without the need for lumbar puncture. Intravenous vancomycin and gentamicin were given. An Ear, Nose, and Throat consultant found no physical signs of neck infection. Contrast computed
tomography (CT) scan of the neck (Figure 1) revealed marked prevertebral soft-tissue edema, consistent with a retropharyngeal-space phlegmon. There was no rim enhancement suggestive of an abscess, and no evidence of osteomyelitis or discitis. Magnetic resonance imaging (MRI) of the neck several days later confirmed these findings. Blood cultures grew MSSA and methicillin-resistant S. aureus (MRSA). The inpatient team was able to retrieve the official reports of his outpatient blood cultures, which had grown MSSA, not Pseudomonas. Transesophageal echocardiography showed no valve vegetations. He was discharged on hospital day 9 when his pain and fever had resolved, with a plan to receive vancomycin and gentamicin at dialysis. One week later he was readmitted to the hospital complaining of fatigue, generalized weakness, and liquid, bloody diarrhea. Colonoscopy showed blood oozing from ectatic rectal vessels, consistent with radiation proctitis. A stool sample was positive for Clostridium dificile toxin. On hospital day 3, he was febrile to 38.9°C (102°F). A blood culture sent on admission grew MSSA. There was now concern that the access graft was infected. An indium-labeled leukocyte scan showed focal uptake at the site of the graft in the right upper arm. He was taken to the operating room to have the graft excised. At operation, the graft was found to be surrounded by pus, and the lumen filled with pus and thrombus. Cultures of the graft grew MRSA. He was discharged on day 11 with a new subclavian hemodialysis catheter and a plan to continue vancomycin and gentamicin for a total of 6 weeks.
Retropharyngeal Phlegmon
DISCUSSION S. aureus is the leading cause of bacteremia in patients receiving hemodialysis, and a major cause of death from sepsis in this population. Most S. aureus bacteremia arises from infections at the access site; conversely, about 75% of access site infections are caused by S. aureus. The risk of bacteremia is higher for polytetrafluoroethylene grafts than for fistulas, and highest for indwelling central venous catheters. Infection of the access site may be clinically silent or associated with only subtle clinical signs such as slight warmth over the graft. Often, clotting of the access is the only sign of an occult infection. In other cases, access site infection becomes apparent only when—as in this case—the patient develops metastatic foci of infection such as endocarditis, septic pulmonary emboli, septic arthritis, or osteomyelitis (2). Hematogenous infection of heart valves, vertebrae, and joints by S. aureus in patients with intravascular catheters has been widely reported. In contrast, we have found only two reports in the recent English-language literature of retropharyngeal soft-tissue infection caused by hematogenous seeding in the setting of S. aureus bacteremia (3,4). One of those patients, described by Hughes et al., was receiving hemodialysis (3). In children, retropharyngeal infections usually arise from infectious foci in adjacent structures such as the mandibular teeth, tonsils, paranasal sinuses, middle ear, parotid gland, and deep cervical lymph nodes. In adults, retropharyngeal infections sometimes arise from a dental or peritonsillar abscess, but are most often a complication of penetrating trauma to the pharynx or esophagus, for example, from endoscopy or a swallowed foreign body such as a chicken bone. They are typically polymicrobial infections with flora derived from the adjacent mucosa, including Streptococcus viridans, Streptococcus pyogenes, Bacteroides and other oral anaerobes, S. aureus, Klebsiella, and Pseudomonas (5). Although intravenous drug abuse is recognized as a risk factor for the development of deep neck abscesses, these infections are generally attributed to injections directly into the deep veins of the neck itself (“shotgunning”) (6,7). Three retropharyngeal “potential spaces” lie between the hypopharynx and the vertebrae. The immediate retropharyngeal space is located between the constrictor muscles of the hypopharynx and the deep layer of cervical fascia. Behind it lies the so-called “danger space,” located between the deep fascia and the prevertebral fascia; this space descends into the mediastinum. Behind this is the prevertebral space, which lies between the prevertebral fascia and the vertebrae; this space extends caudally to the coccyx (8). Due to the caudal extension of
165
these spaces, deep neck infections can lead to mediastinitis and even psoas abscess. In this case it was not possible, even with high-resolution CT and MRI, to determine which of the closely apposed retropharyngeal spaces was the center of infection. The symptoms of retropharyngeal space infection can include sore throat, odynophagia, dysphagia, neck pain, and trismus. Examination may reveal neck erythema, swelling, doughy consistency, pitting edema, or lymphadenopathy (5). However, retropharyngeal infections are often difficult to diagnose clinically, and can be easily confused with pharyngitis, epiglottitis, cervical osteomyelitis, or meningitis. Prevertebral soft-tissue swelling on lateral neck X-ray study is suggestive; CT scan and MRI provide more specific anatomic information and can differentiate between a cellulitis or phlegmon, which can be treated with intravenous antibiotics, and an abscess that may require surgical drainage (9).
CONCLUSIONS We report this case to raise awareness among emergency physicians of the possibility of retropharyngeal infection in a patient with S. aureus bacteremia who complains of sore throat or neck pain. This infection can arise by hematogenous spread from a distant site. In a hemodialysis patient, the dialysis access graft or catheter should be evaluated as a potential source of unexplained bacteremia, even when clinical signs of access site infection are absent.
REFERENCES 1. Mitchell DH, Howden BP. Diagnosis and management of staphylococcus aureus bacteremia. Intern Med J 2005;35(Suppl 2): S17–24. 2. Marr KA. Staphylococcus aureus bacteremia in patients undergoing hemodialysis. Semin Dial 2000;13:23–9. 3. Hughes J, Martin RJ, Clutterbuck EJ. Retropharyngeal infection with Staphylococcus aureus in a haemodialysis patient. Am J Nephrol 1993;13:435– 6. 4. Sato K, Izumi T, Toshima M, et al. Retropharyngeal abscess due to methicillin-resistant Staphylococcus aureus in a case of acute myeloid leukemia. Intern Med 2005;44:346 –9. 5. Chow AW. Life-threatening infections of the head, neck, and upper respiratory tract. In: Hall JB, Schmidt GA, Wood LD, eds. Principles of critical care. New York: McGraw-Hill; 1998:887–902. 6. Har-El G, Aroesty JH, Shaha A, Lucente FE. Changing trends in deep neck abscess. Oral Surg Oral Med Oral Pathol 1994;77: 446 –50. 7. Parhiscar A, Har-El G. Deep neck abscess: a retrospective review of 210 cases. Ann Otol Rhinol Laryngol 2001;110:1051– 4. 8. Barratt GE, Koopman CF, Coulthard SW. Retropharyngeal abscess—a ten-year experience. Laryngoscope 1984;94:455– 63. 9. Gidley PW, Ghorayeb BY, Stiernberg CM. Contemporary management of deep neck space infections. Otolaryngol Head Neck Surg 1997;116:16 –22.