The utility of arterial blood gas parameters and chest radiography in predicting appropriate intubations in burn patients with suspected inhalation injury-A retrospective cohort study.

BACKGROUND: This study evaluates the utility of arterial blood gas (ABG) parameters and chest radiography in predicting intubation need in patients with burn injuries with suspected inhalation injury. METHODS: Patients with suspected inhalation injury admitted to a single centre, Burn Intensive Care Unit, between April 4th 2016 and July 5th 2019, were included. Admission ABG parameters and chest radiograph opacification were compared with whether the patient received an appropriate intubation: defined as intubation for a duration of over 48 h. Area under the receiver operator characteristic curve was calculated (AUROC). RESULTS: Eighty-nine patients were included. The majority (84%; n = 75) were intubated, of which 81% (n = 61) received appropriate intubations. pH had an AUROC of 0.88 and a pH of <7.30 had an 80% sensitivity and specificity for detecting appropriate intubation. P/F ratio had an AUROC of 0.81 and a P/F ratio of <40 had a 70% sensitivity and specificity for appropriate intubation. Chest radiograph opacification had poor utility in this regard (AUROC = 0.69). Adding pH and P/F ratio to the ABA criteria improved their sensitivity in detecting appropriate intubations (sensitivity: ABA + pH + P/F = 0.97 vs ABA = 0.86; p = 0.013), without altering their specificity. CONCLUSIONS: In patients suspected inhalation injury, pH and P/F ratio were good predictors for appropriate intubations. Incorporating the parameters into the ABA criteria improved their clinical utility.

The Predictive Applicability of Liberal vs Restrictive Intubation Criteria in Adult Patients With Suspected Inhalation Injury-A Retrospective Cohort Study.

This study compares the ability of liberal vs restrictive intubation criteria to detect prolonged intubation and inhalation injury in burn patients with suspected inhalation injury. Emerging evidence suggests that using liberal criteria may lead to unnecessary intubation in some patients. A single-center retrospective cohort study was conducted in adult patients with suspected inhalation injury admitted to intensive care at Queen Elizabeth Hospital, Birmingham between April 2016 and July 2019. Liberal intubation criteria, as reflected in local guidelines, were compared to restrictive intubation criteria, as outlined in the American Burn Association guidelines. The number of patients displaying positive characteristics from either guideline was compared to the number of patients who had prolonged intubation (more than 48 hours) and inhalation injury. In detecting a need for prolonged intubation (n = 85), the liberal criteria had greater sensitivity (liberal = 0.98 [0.94-1.00] vs restrictive = 0.84 [0.75-0.93]; P = .013). However, the restrictive criteria had greater specificity (restrictive = 0.96 [0.89-1.00] vs liberal = 0.48 [0.29-0.67]; P < .001). In detecting inhalation injury (n = 72), the restrictive criteria were equally sensitive (restrictive = 0.94 [0.87-1.00] vs liberal = 0.98 [0.84-1.00]; P = .48) and had greater specificity (restrictive = 0.86 [0.72-1.00] vs liberal = 0.04 [0.00-0.13]; P < .001). In patients who met liberal but not restrictive criteria, 65% were extubated within 48 hours and 90% did not have inhalation injury. Liberal intubation criteria were more sensitive at detecting a need for prolonged intubation, while restrictive criteria were more specific. Most patients intubated based on liberal criteria alone were extubated within 48 hours. Restrictive criteria were highly sensitive and specific at detecting inhalation injury.

Review of the Diagnostic Evaluation of Renal Tubular Acidosis.

BACKGROUND: The term renal tubular acidosis (RTA) describes a group of uncommon kidney disorders characterized by defective acid-base regulation. Reaching the diagnosis of RTA is complex and often delayed, resulting in suboptimal treatment. METHODS: This article provides an overview of the clinical features of RTA and diagnostic approaches in a format accessible to physicians for everyday use. RESULTS: The 3 major forms of disease are classified by their respective tubular transport defects, each of which produces persistent hyperchloremic metabolic acidosis. Distal RTA is characterized by limited urinary acid secretion, proximal RTA by restricted urinary bicarbonate reabsorption, and hyperkalemic RTA by absolute or relative hypoaldosteronism. RTA is often detected incidentally as a biochemical diagnosis in asymptomatic individuals. When present, clinical features may range from mild nonspecific complaints to life-threatening physiologic disturbances. CONCLUSION: RTA is a complex condition that requires thoughtful investigation. Physicians should be aware of the presentation of RTA and the investigative options available to confirm the diagnosis.