Urinary desmosine as a biomarker in acute lung injury.

Acute lung injury (ALI) is a complex disorder associated with an acute inflammatory response thought to contribute to tissue injury. Desmosine, a cross-linking amino acid present in elastin, is released during matrix degradation and cleared by the kidney. Results from animal models and human disease studies have suggested that ALI is associated with the release of desmosine, resulting in increased urinary desmosine. A radioimmunoassay was used to monitor urinary desmosine levels over 10 days in ten patients with ALI. The concentration of desmosine was measured with and without acid hydrolysis. Baseline urinary desmosine was increased in two of ten patients. The concentration of desmosine at baseline did not appear to be related to age, gender, neutrophil elastase (NE)/alpha(1)-antiprotease complex concentration or P(a)O(2)/F(i)O(2) ratio. No meaningful changes in desmosine levels were noted after removal from mechanical ventilation. Baseline desmosine concentrations did not appear to correlate with the risk of death. The limited sensitivity, predictive correlations and dynamic modulation would suggest that urine desmosine has a limited role as a biomarker for ALI. Hydrolysis of urine samples appears necessary for optimal measurement of urine desmosine.

Systemic pharmacologic therapy of ARDS.

The increased understanding of the pathophysiology of acute lung injury that has been achieved over the last decade has led to several new pharmacologic approaches for the prevention and management of ARDS. Based on in vitro information and animal models, many of these strategies are quite compelling. Nevertheless, to date, no specific pharmacologic approach for the prevention or treatment of ARDS has been validated conclusively in clinical trials. Active basic and clinical investigations are continuing, and it is hoped that these will lead to new therapies that can be applied by the clinician in the management of future ARDS patients.

The impact of a postoperative oxygen therapy protocol on use of pulse oximetry and oxygen therapy.

BACKGROUND: Recent evidence suggests that both pulse oximetry monitoring and oxygen (O2) therapy may be used inappropriately at times, implying the need for improved use of pulse oximetry by health-care providers. METHODS: We studied the clinical and financial impact of a postoperative O2-therapy protocol in 2 groups of patients. Group 1 (n = 20) was comprised of patients whose physicians made all O2 therapy management decisions. Group 2 (n = 20) was comprised of patients whose O2 therapy management was performed by respiratory therapists according to an algorithm with a stop criterion of SpO2 > or = 92%. The duration of postoperative O2 therapy, the frequency of unnecessary O2 therapy, and group totals of SpO2 measurements were compared between groups using the Mann-Whitney Rank Sum Test. RESULTS: O2 therapy was used on average (SD) 3.45 (1.28) days/patient in Group 1 and 2.1 (0.64) days/patient in Group 2 (p < 0.003). Sixteen Group-1 patients continued to receive O2 at least 24 hours after achieving a room-air SpO2 > or = 92%. Group 1 had 57 SpO2 measurements and Group 2 had 24 (p < 0.003). No adverse clinical events ascribed to hypoxemia were noted in either group. CONCLUSIONS: Our experience suggest that implementing a uniform, clinically appropriate 'stop criterion' for low-flow O2 therapy in nonthoracic postoperative patients can shorten the duration of O2 therapy and reduce the number of SpO2 measurements without incurring additional complications.