A Distinct Difference Between Air and Mucosal Temperatures in Human Respiratory Tract.

Extensive evidence indicates that several types of temperature-sensitive ion channels are abundantly expressed in the sensory nerves innervating airway mucosa. Indeed, airway temperature is known to play an important role in regulating respiratory functions. However, the actual airway mucosal temperature and its dynamic changes during the respiratory cycle have not been directly measured. In previous studies, airway tissue temperature was often estimated by indirect measurement of the peak exhaled breath temperature (PEBT). In view of the poor thermal conductivity of air, we believe that the airway tissue temperature cannot be accurately determined by the exhaled air temperature, and this study aimed to test this hypothesis. We applied a miniature rapid-response temperature probe to measure directly the mucosal temperatures of trachea, major, lobar, and segmental bronchi in eight human subjects during a bronchoscopy procedure. Unlike the air temperature in the airway lumen, the mucosal temperature in these airway segments remained relatively stable and did not exhibit the phasic changes synchronous with respiratory cycles. The airway mucosal temperature increased progressively from the extra-thoracic trachea (35.7 ± 0.2°C) toward the segmental bronchus (36.9 ± 0.2°C). Most importantly, the temperatures measured directly at the mucosa of all these airway segments were substantially higher than the PEBT (31.7 ± 0.8°C). The recent findings of a close association between an increased PEBT and airway tissue inflammation have revealed the implication and potential of incorporating the PEBT measurement in the future clinical diagnosis of airway inflammation. Therefore, it is imperative to recognize this distinct difference in temperature between airway mucosa and exhaled air.

Acute undifferentiated febrile illness: Protocol in emergency department.

Fever accounts for around 15% of emergency visits in elderly age group and around 5% in adults. The spectrum of etiologies ranges from non-infectious to infectious etiologies. There are very few studies done in the past highlighting the approach of patients with acute febrile illness without any localizing signs and symptoms. OBJECTIVES: The aim of the study was to formulate a targeted approach for evaluation and treatment of patients with acute undifferentiated febrile illness without evidence of localizing symptoms and signs. The secondary objective was to study the etiology and final outcome of patients with acute undifferentiated febrile illness. MATERIALS AND METHODS: A protocol was devised for patients aged more than 18 years, who presented in emergency department with complaints of fever without localizing symptoms or signs of sepsis over a period of 6 months from April 2018 to September 2018. Patient's data were collected retrospectively from the hospital record section. RESULTS: A total of 212 patients of undifferentiated acute febrile illness were enrolled in the study. Maximum number of patients [n = 69 (32.5%)], presented on second day of illness. All the patients presenting within 1 or 2 days of fever experienced defervescence. Out of these 69 patients, 35 (36.4%) were investigated of which in 29 (82.2%) investigations were not found to be useful; 75 (78.1%) patients with 1 or 2 days history of fever improved without investigations. Surprisingly, 54 patients (72%) with 1 or 2 days' history of acute febrile illness experienced defervescence without the need of antibiotics. CONCLUSION: There is an urgent need to devise a standardized protocol for diagnosis and treatment of patients with acute undifferentiated febrile illness in order to avoid unnecessary investigations and antimicrobial use.

New brain lesions in a patient with sarcoidosis: is it neurosarcoidosis?

A 45-year-old woman with pulmonary sarcoidosis diagnosed 5 years previously, who was on treatment with prednisone and methotrexate for 1year, developed partial seizure with secondary generalization. MRI showed three non-cavitary enhancing lesions in the cerebello-occipital region. These lesions were presumed to be neurosarcoidosis. Methotrexate was discontinued, prednisone dose was increased and azathiopurine and levetiracetam were added. While on treatment, follow up imaging showed enlarging brain lesions. Biopsy of the lesions showed Epstein Barr virus (EBV) positive diffuse B cell lymphoma. Immunosuppressants were tapered off and she was begun on Rituximab. Because of lack of improvement after 4 cycles of Rituximab, she was then treated with high dose Methotrexate and Temozolamide. We present this case as a diagnostic challenge. New enhancing brain lesions occurring in a patient with long standing sarcoidosis, while likely to be neurosarcoidosis, may be due to a complication of immunosuppressant therapy. The need for early biopsy, if the lesions do not improve, should be considered.