Two lost airways and one unexpected problem: undiagnosed tracheal stenosis in a morbidly obese patient.

Anesthetic care of the morbidly obese is complex due to anatomic and physiologic alterations. Airway management in particular can be challenging. High body mass index is predictive of difficult ventilation and possibly difficult intubation. Other airway anomalies, such as tracheal stenosis, add to the complexity of airway management. Tracheal stenosis, a form of central airway obstruction, may be challenging to diagnose, especially in the obese. Comorbidities can mask the diagnosis and routine imaging may fail to identify the pathology. We present the case of a morbidly obese patient with 2 failed intubations due to difficult anatomy compounded with undiagnosed tracheal stenosis.

Prehospital intubations and mortality: a level 1 trauma center perspective.

BACKGROUND: Ryder Trauma Center is a Level 1 trauma center with approximately 3800 emergency admissions per year. In this study, we sought to determine the incidence of failed prehospital intubations (PHI), its correlation with hospital mortality, and possible risk factors associated with PHI. METHODS: A prospective observational study was conducted evaluating trauma patients who had emergency prehospital airway management and were admitted during the period between August 2003 and June 2006. The PHI was considered a failure if the initial assessment determined improper placement of the endotracheal tube or if alternative airway management devices were used as a rescue measure after intubation was attempted. RESULTS: One-thousand-three-hundred-twenty patients had emergency airway interventions performed by an anesthesiologist upon arrival at the trauma center. Of those, 203 had been initially intubated in the field by emergency medical services personnel, with 74 of 203 (36%) surviving to discharge. When evaluating the success of the intubation, 63 of 203 (31%) met the criteria for failed PHI, all of them requiring intubation, with only 18 of 63 (29%) surviving to discharge. These patients had rescue airway management provided either via Combitube (n = 28), Laryngeal Mask Airway (n = 6), or a cricothyroidotomy (n = 4). An additional 25 of 63 patients (12%) had unrecognized esophageal intubations discovered upon the initial airway assessment performed on arrival. We found no difference in mortality between those patients who were properly intubated and those who were not. Several other variables, including age, gender, weight, mechanism of injury, presence of facial injuries, and emergency medical services were not correlated with an increased incidence of failed intubations. CONCLUSION: This prospective study showed a 31% incidence of failed PHI in a large metropolitan trauma center. We found no difference in mortality between patients who were properly intubated and those who were not, supporting the use of bag-valve-mask as an adequate method of airway management for critically ill trauma patients in whom intubation cannot be achieved promptly in the prehospital setting.

Purification and characterization of PLUNC from human tracheobronchial secretions.

To study proteins secreted into the airway, we used secretions from primary human airway epithelial cells, re-differentiated at the air-liquid interface, and from patients intubated during surgery. A major protein of the cultured cell secretions was ethanol soluble. This protein was purified, analyzed by Edman degradation, matrix-assisted laser-desorption ionization time-of-flight mass spectroscopy of tryptic digests, and Western blots of two-dimensional electrophoresis gels using antisera against the purified preparation. The protein was identified as palate, lung, nasal epithelium clone protein (PLUNC). The protein had multiple truncated molecules, a pattern also seen in tracheal aspirates. PLUNC was poorly soluble in water (50 microg/ml) or in 50 mM NaCl but was more soluble in 75% ethanol (> 380 microg/ml). PLUNC secretion dramatically increased during the second week in air-liquid interface culture and continued to increase over time. Immunohistochemistry showed that PLUNC was expressed in human airway epithelium and submucosal glands. Although PLUNC is in the lipopolysaccharide (LPS)-binding protein (LBP) and bactericidal/permeability-increasing protein family of antibacterial host defense proteins, purified PLUNC failed to compete with LBP for the binding of LPS, whereas polymyxin B, a known inhibitor of LPS-LBP binding, did interfere with binding. This study showed that plunc gene product is expressed both in vivo and in vitro, detailed a method for its purification and provided basic information on its biochemical properties in secretions.

Lactoperoxidase and human airway host defense.

The lactoperoxidase (LPO) antibiotic system is a well-characterized component of mammary and salivary gland secretions. Because LPO has been shown to function in ovine airways, human airway tissue and secretions were examined for the presence of LPO and its substrate, the anion thiocyanate (SCN-). In addition, human airway secretions were tested for LPO-mediated antibacterial activity, and LPO's activity was assessed against some human airway pathogens. The data showed that normal human airway secretions contained LPO enzyme activity (0.65 +/- 0.09 microg/mg secreted protein; n = 17), and Western blots of secretions demonstrated bands of the expected sizes for LPO. LPO mRNA was detected in trachea by sequencing PCR-amplified cDNA. SCN-, LPO's substrate, was present in undiluted airway secretions at concentrations sufficient for LPO catalysis (0.46 +/- 0.19 mM; n = 8), and diluted secretions contained antibacterial activity with LPO-like properties. Immunocytochemistry localized LPO to submucosal glands in human bronchi. Finally, as expected based on the known antibacterial spectrum of the LPO system, airway secretions showed LPO-dependent activity against Pseudomonas aeruginosa. In addition, the airway LPO system was shown to be effective against Burkholderia cepacia and Haemophilus influenzae. Thus, a functional LPO system exists in human airways and may contribute to airway host defense against infection.