A 26-year-old man with progressive chest pain and respiratory distress was transported
as an emergency case to our hospital from the local airport. He had just returned to
Japan from traveling in southeastern Asia for 1 week. He had no relevant past medical
history and was not on medication. He had developed pain in the right lower mandibular
area over the past week. The pain had progressed from the neck to the chest; he
developed a high fever during his journey and could not eat or drink. In the emergency
room, peripheral oxygen saturation was 95% with receiving oxygen at 15 L/min via an
oxygen mask and a reservoir bag. A chest X-ray showed a slightly widened mediastinum
with pleural effusion (). An
ECG revealed widespread ST-elevation (). Physical examination revealed a body mass index of 23.0 kg/m2
(height 168.0 cm; weight 65.0 kg), blood pressure of 121/68 mmHg, average heart rate of
110/min, respiratory rate of 40 breaths/min, body temperature of 37.9°C, and
tenderness and redness in the anterior and bilateral sides of the neck. White blood cell
count was 14,510/µL, neutrophils were 11,320/µL, red blood cell count
was 5.07×106/µL, hemoglobin was 14.7 g/dL, and the platelet
count was 196,000/µL. C-reactive protein level was elevated at 54.52 mg/dL (ref.
0.0–0.14 mg/dL). Blood urea nitrogen and creatinine levels were 45 mg/dL (ref.
8–20 mg/dL) and 1.06 mg/dL (ref. 0.65–1.07 mg/dL), respectively. Lactate
dehydrogenase was elevated to 510 U/L (ref. 124–222 U/L). Creatine kinase and
creatine kinase-MB were 269 (ref. 59–248 U/L) and 11.6 (ref. 0.0–12.0
U/L), respectively. The fasting blood glucose and HbA1c levels were normal. Although
these findings indicated the possibility of acute pericarditis, an ECG did not show any
findings of pericarditis or myocardial dysfunction. Contrast-enhanced CT images revealed
that a large volume of gas had collected in the neck and upper and anterior mediastinum
(). In addition,
an abscess had formed in the retropharyngeal, bilateral sub-mandibular, upper
paratracheal, and mediastinal spaces with pleural effusion and atelectasis in the right
lower basal lobe (). Thus, DNM induced by odontogenic infection with a right mandibular
second or third molar abscess was highly suspected.
A multidisciplinary team, including physicians, otolaryngologists, surgeons, and
intensivists commenced treatment within 2 hours of arrival. He received intravenous 600
mg clindamycin bid and 4.5 g tazobactam/piperacil-lin hydrate qid. A tracheostomy,
bilateral neck drainage, neck fasciotomy, and debridement via a cervical incision were
performed 5 hours after arrival. The blood culture on admission was negative.
Gram-positive cocci were found in sputum and pus, and Streptococcus
pyogenes, Streptococcus constellatus, Fusobacterium
necrophorum, and Peptostreptococcus sp. were found later in
pus culture. Continuous bilateral thoracic drainage began due to the development of a
bilateral pyothorax. Subsequently, the transcervical mediastinal and right mediastinal
areas were drained via thoracotomy. His condition improved steadily, and he was
discharged without any comorbidities on hospital day 63 after admission. Pathological
findings from the excised skeletal muscle and fascia indicated acute inflammation with
necrosis (),
consistent with necrotizing fasciitis, and a large number of Gram-positive cocci were
observed (). Thus, the
radiological diagnosis of DNM was confirmed histologically and bacteriologically.
The formula for computing Cockcroft-Gault is given by CrCl = ((140 - age) * adjusted weight * (gender_coefficient)) / (serum creatinine * 72), where the gender_coefficient is 1 if male, and 0.85 if female. The serum creatinine concentration is in mg/dL.
The patient's gender is male, which means that the gender coefficient is 1.
The patient is 26 years old. 
The concentration of creatinine is 1.06 mg/dL. 
The formula for computing the patient's BMI is (weight)/(height * height), where weight is the patient's weight in kg and height is the patient's height in m.
The patient's height is 168.0 cm, which is 168.0 cm * 1 m / 100 cm = 1.68 m. The patient's weight is 65.0 kg. The patient's bmi is therefore 65.0 kg / (1.68 m * 1.68 m) = 23.03 kg/m^2.The patient's BMI is 23.0, indicating they are normal weight.
Because the patient is normal, we take take minimum of the ideal body weight and the patient's body as the patient's adjusted weight for the Cockroft-Gault Equation. Hence, the adjusted body weight is the minimum of the two giving us an adjusted body weight of 64.127 kg.

Using the Cockcroft-Gault equation:
CrCl = ((140 - age) * adjusted weight * gender_coefficient) / (serum creatinine * 72).
Plugging the patient's values gives us ((140 - 26) * 64.127 * 1) / (1.06 * 72) = 95.787 mL/min. Hence, the patient's creatinine clearance is 95.787 mL/min.