Vocal cord dysfunction related to combat deployment.

OBJECTIVES: Several etiologies for vocal cord dysfunction (VCD), a syndrome of dyspnea, noisy breathing, and inspiratory vocal cord closure are suggested; there is no consensus on the predisposition to its development. One previously identified psychiatric etiology is combat stress. METHODS: A retrospective review of military personnel evaluated at Landstuhl Regional Medical Center with a new VCD diagnosis post-deployment was conducted. Medical records were reviewed for existing pulmonary, sinus, esophageal, or psychiatric disorders and determined their VCD evaluation. RESULTS: Forty-eight patients were identified with VCD symptoms after combat deployment. For military personnel with VCD, symptoms were associated with several etiologies. Fifty-two percent reported symptoms were related to high stress/anxiety, whereas 39% reported symptoms during exercise; 16% had onset with acute respiratory illness and 7% were trauma related. The combination of a truncated inspiratory flow volume loop and negative methacholine challenge had a 72% positive predictive value. CONCLUSIONS: Common etiologies with VCD onset during deployment are anxiety/stress, exercise, or combination of factors. Spirometry with abnormal flow volume loop plus negative methacholine challenge testing offers a reasonable predictive value for diagnosing VCD. For deployed military with these findings, laryngoscopy for upper airway disorders should be conducted.

Inflammatory mediators in smoke inhalation injury.

Smoke inhalation occurs in 10% to 30% of patients admitted to burn centers, and increases mortality by a maximum of 20% over that predicted by age and extent of cutaneous burn alone. Pneumonia in these patients then further increases mortality by a maximum of 40%. While one estimate suggested that 75% of deaths following burn injury may be accounted for by inhalation injury, more recent cohort studies have suggested there is a decreasing mortality attributable to inhalation injury. As part of understanding and improving outcomes from burn injuries, the pathophysiology and inflammatory processes involved in smoke inhalation injury has been extensively investigated in animal models. This review will emphasize the inflammatory pathways involved in inhalation injury, and targeted methods used to treat this injury in both experimental and human models.

Inspiratory flow-volume curve evaluation for detecting upper airway disease.

BACKGROUND: The 2005 American Thoracic Society/European Respiratory Society guidelines on spirometry emphasize examination of the inspiratory curve of the flow-volume loop for evidence of intrathoracic or extrathoracic upper airway obstruction. We sought to determine how frequently evaluations are performed for abnormal inspiratory curves. METHODS: We retrospectively reviewed all examinations performed in our pulmonary function testing laboratory over a 12-month period (n = 2,662). In patients with normal spirometry or a mild restrictive defect, we inspected the inspiratory curves for truncation, flattening, or absent loop. With patients who had an abnormal inspiratory curve, we examined 3 flow-volume loops to determine if more than one loop showed an inspiratory abnormality, and to assess changes in the mid-flow ratio (ratio of forced expiratory flow at 50% of the forced expiratory volume to forced inspiratory flow at 50% of the forced inspiratory volume), and we used the loop that had the best inspiratory and expiratory curves. We reviewed the medical records for underlying disease processes and evidence of upper airway evaluation. RESULTS: One hundred twenty-three patients (4.6%) had an abnormal inspiratory curve. Sixty-nine (56%) of those 123 patients had inspiratory abnormalities on > 2 flow-volume loops. Evaluation of the inspiratory abnormality was undertaken in only 17% of all patients, and 30% of patients who had consistently abnormal inspiratory curves. A specific etiology was identified in 52% of the evaluated patients. Vocal cord dysfunction was the most frequent diagnosis. Utilizing the loop that had the combination of the best inspiratory and expiratory curves decreased the mid-flow ratio from 3.07 +/- 1.63 to 1.77 +/- 1.15. CONCLUSIONS: An abnormal inspiratory curve in the presence of otherwise normal spirometry should prompt an evaluation for the etiology. If one of the flow-volume inspiratory curves shows an abnormality, all the inspiratory curves from that PFT session should be reviewed, and if more than one inspiratory curves is abnormal, both anatomical and functional evaluation should be undertaken for intrathoracic and extrathoracic upper airway obstruction.