Systemic emphysema accompanying marked undernutrition

Abstract

Case

A 38‐year‐old mentally retarded woman was transported to the emergency room for marked undernutrition. Two months prior, she had developed tooth decay and her food intake decreased severely. Over 2 months, her weight decreased from 47 to 31 kg (−16 kg). Computed tomography (CT) revealed extensive subcutaneous, mediastinal, and retroperitoneal emphysema. She was hospitalized and treatment with central venous hyperalimentation and antibiotics was initiated. CT performed 3 weeks after hospitalization showed that the systemic emphysema had completely disappeared.

Outcome

She progressed favorably and was transferred to a specialized psychiatric hospital for further treatment.

Conclusion

Regardless of the cause, this rare complication must be taken into account when treating patients suffering from long‐term starvation or undernutrition. Whole‐body management including nutritional management and careful follow‐up observations are appropriate for treating this condition.

Introduction

Although extremely rare, systemic emphysema accompanying marked undernutrition has been reported. This emphysema is characterized by non‐infectious and resolve naturally with conservative treatment. Together with a review of the literature, we describe a case of severe systemic emphysema.

Case Presentation

A 38‐year‐old woman had mental retardation but was able to perform daily living activities independently and also engaged in light work at a workshop on weekdays. Two months prior to presentation, she had developed tooth decay and her food intake decreased severely due to the pain. Also, 2 weeks prior to presentation, she had undergone a tooth extraction at her dental office. However, the pain continued and she became unable to consume any of her meals. Over 2 months, her weight decreased from 47 to 31 kg (−16 kg). She became increasingly attenuated and eventually found it difficult to move. Her mother requested an ambulance and the patient was transported to the emergency room at our hospital.

Physical findings were 150 cm (height), 31 kg (weight), and 13.8 kg/m² (body mass index), indicating marked emaciation. Her consciousness level was at Glasgow Coma Scale (GCS) level E3V4M6. Vital signs were measured. Blood pressure (BP) was 106/75 mmHg, and body temperature was 36.3 °C. Her heart rate was 140 beats/min (sinus rhythm), indicating tachycardia and her respiratory rate was 18 breaths/min, indicating tachypenea. Her saturation pulse oxygen (SpO2) was 97% (room air). Palpation of the neck and back region indicated snowball crepitation and subcutaneous emphysema was suspected. Chest X‐ray revealed subcutaneous and mediastinal emphysema (Fig. 1). Computed tomography (CT) revealed extensive subcutaneous, mediastinal, and retroperitoneal emphysema (Fig. 2). Examination of her systemic skin indicated no reddening, warmth, or tenderness thus ruling out infection. The patient exhibited no vomiting or coughing episodes and had no chest pain.

Figure 1.

Plain chest radiograph. Subcutaneous emphysema and mediastinal emphysema observed.

Figure 2.

Computed tomography (CT) image. (A) Extensive subcutaneous emphysema noted in subcutaneous soft tissue. Mediastinal emphysema also observed. (B) Retroperitoneal emphysema finding (air surrounding both kidneys) observed (arrowhead). (C, D) Three weeks after treatment. Subcutaneous emphysema, mediastinal emphysema, and retroperitoneal emphysema had completely disappeared.

Blood test results indicated a creatinine (Cre) level of 3.06 mg/dL, serum natrium (Na) 179 mEq/L, and creatinine kinase (CK) at 1,402 U/L, indicating renal dysfunction, hypernatremia, and hyperCKemia. Serum albumin (Alb) was 2.2 g/dL, indicating a state of undernutrition. An inflammatory response was noted, with mild elevation of white blood cells (WBC) (11,000/μL) and C‐reactive protein (CRP) (2.21 mg/dL). In addition, the serum procalcitonin level was 0.41 ng/mL. Blood culture was negative, and no Streptococus pyogenes were detected from the nasal cavity or throat swab culture.

The patient was diagnosed with marked undernutrition, acute renal failure, and systemic emphysema. She was hospitalized and treatment was initiated. Because she refused oral feeding, she was administered nutritional management via central venous hyperalimentation and adequate fluid replacement. Because the possibility of infection by gas‐producing bacteria could not be eliminated, administration of Meropenem 1 g/day was started. After 1 week no signs of infection were noted and antibiotic administration was discontinued. After 2 weeks of hospitalization, Cre, Na, and CK levels normalized to 0.59 mg/dL, 140 mEq/L, and 51 U/L, respectively. Alb increased to 3.0 g/dL. The patient had a dental exam and treatment for dental caries was continued. However, she continued to refuse oral feeding and was subsequently examined by the department of psychiatry. The results of this exam indicated that the patient was refusing meals because she had developed an obsession that oral feeding would exacerbate her pain. We determined that she refused oral feeding due to mental retardation and had not developed anorexia nervosa. With the informed consent of her family, a nasogastric tube was inserted and tubal feeding was initiated.

Computed tomography performed 3 weeks after hospitalization showed that the subcutaneous, mediastinal, and retroperitoneal emphysema had completely disappeared (Fig. 2). She progressed favorably and was transferred to a specialized psychiatric hospital for further treatment.

Discussion

Although extremely rare, systemic emphysema accompanying anorexia nervosa has been reported.1, 2, 3 Liang‐Yu et al.4 reviewed 11 cases and found that many were young women with markedly low body weight (mean body mass index [BMI]: 12.1 kg/m²). Self‐induced vomiting was exhibited in only four of the 11 cases, indicating that most cases had developed without any clear indications. There are also some cases with no relation to anorexia nervosa in young women. Choo et al.5 reported an idiopathic pneumomediastinum in an 18‐year‐old girl, no history of other illness reported. However, her body weight and BMI were not described. Chatfield et al.6 reported a case of a lady with a history of 18 kg weight loss due to urinary tract infection and hyperemesis gravidarum. Regardless of the cause, the possibility of development of this rare complication must be taken into account when treating patients suffering from long‐term starvation or undernutrition.

The mechanism for the onset of systemic emphysema is considered to involve weakening of soft tissue and decreased elasticity of alveoli due to undernutrition.7, 8 A study involving an experiment with rats reported that long‐term starvation caused decreased alveolus elasticity.9 It is likely that marked undernutrition in humans will also increase the risk for alveoli rupture. Alveoli may rupture spontaneously with no or only a slight stimulation, and the air leaking into the stroma causes less resistant parts of the tissue surrounding the blood vessels to detach while it travels toward the pulmonary hilum; subsequently, it reaches the mediastinum and becomes a mediastinal emphysema.4 A possible hypothesis is that when pressure increases within the mediastinum, air is carried along the aorta and esophagus, causing the development of subcutaneous and mediastinal emphysema.

Reasons for pneumothorax not occurring despite rupture of alveoli may include the following: (i) unlike spontaneous pneumothorax, the site of alveoli rupture is not necessarily in contact with the visceral pleura, and rupture of visceral pleura is unlikely to occur; (ii) leakage of air from the ruptured alveoli into the pulmonary stroma occurs before outflow into the thoracic cavity; the air flows from the pulmonary stroma into the weakened soft tissue.4, 8

Previous reports indicated that systemic emphysema resolved naturally with conservative treatment and follow‐up observations.1, 2, 3, 4, 5, 6, 8 Whole‐body management including nutritional management and careful follow‐up observations are appropriate for treating this condition.

One differential diagnosis is soft tissue infection caused by gas‐producing bacteria.9 In many cases, the differential diagnosis can be made based on clinical signs. Our patient exhibited asymptomatic, systemic emphysema and showed no indication of reddening or tenderness suggestive of inflammation of the skin. Furthermore, elevation of the inflammatory response was mild, and bacterial infection was deemed negative on the basis of low procalcitonin levels and negative results of blood, nasal cavity, and throat culture.

It is difficult to reach a consensus regarding the use of antibiotics. In our case, we administered antibiotics for a limited period of one week only and quickly discontinued administration when no signs of infection were exhibited. We suggest that if antibiotics are used, they should be administered in a restricted manner.

Conclusions

In rare cases, patients with severe undernutrition may develop extensive, systemic emphysema. Many of these cases improve with conservative treatment; the appropriate response is careful follow‐up observations including nutritional management. A differential diagnosis must be made to eliminate the possibility of infection due to gas‐producing bacteria.

Conflict of Interest

None.