Effect of Bronchoscopy on Gas Exchange and Respiratory Mechanics in Critically Ill Patients With Atelectasis: An Observational Cohort Study.

Background: Atelectasis frequently develops in critically ill patients and may result in impaired gas exchange among other complications. The long-term effects of bronchoscopy on gas exchange and the effects on respiratory mechanics are largely unknown. Objective: To evaluate the effect of bronchoscopy on gas exchange and respiratory mechanics in intensive care unit (ICU) patients with atelectasis. Methods: A retrospective, single-center cohort study of patients with clinical indication for bronchoscopy because of atelectasis diagnosed on chest X-ray (CXR). Results: In total, 101 bronchoscopies were performed in 88 ICU patients. Bronchoscopy improved oxygenation (defined as an increase of PaO2/FiO2 ratio > 20 mmHg) and ventilation (defined as a decrease of > 2 mmHg in partial pressure of CO2 in arterial blood) in 76 and 59% of procedures, respectively, for at least 24 h. Patients with a low baseline value of PaO2/FiO2 ratio and a high baseline value of PaCO2 were most likely to benefit from bronchoscopy. In addition, in intubated and pressure control ventilated patients, respiratory mechanics improved after bronchoscopy for up to 24 h. Mild complications, and in particular desaturation between 80 and 90%, were reported in 13% of the patients. Conclusions: In selected critically ill patients with atelectasis, bronchoscopy improves oxygenation, ventilation, and respiratory mechanics for at least 24 h.

Predicting a low cortisol response to adrenocorticotrophic hormone in the critically ill: a retrospective cohort study.

INTRODUCTION: Identification of risk factors for diminished cortisol response to adrenocorticotrophic hormone (ACTH) in the critically ill could facilitate recognition of relative adrenal insufficiency in these patients. Therefore, we studied predictors of a low cortisol response to ACTH. METHODS: A retrospective cohort study was conducted in a general intensive care unit of a university hospital over a three year period. The study included 405 critically ill patients, who underwent a 250 microg ACTH stimulation test because of prolonged hypotension or need for vasopressor/inotropic therapy. Plasma cortisol was measured before and 30 and 60 min after ACTH injection. A low adrenal response was defined as an increase in cortisol of less than 250 nmol/l or a peak cortisol level below 500 nmol/l. Various clinical variables were collected at admission and on the test day. RESULTS: A low ACTH response occurred in 63% of patients. Predictors, in multivariate analysis, included sepsis at admission, low platelets, low pH and bicarbonate, low albumin levels, high Sequential Organ Failure Assessment score and absence of prior cardiac surgery, and these predictors were independent of baseline cortisol and intubation with etomidate. Baseline cortisol/albumin ratios, as an index of free cortisol, were directly related and increases in cortisol/albumin were inversely related to disease severity indicators such as the Simplified Acute Physiology Score II and Sequential Organ Failure Assessment score (Spearman r = -0.21; P < 0.0001). CONCLUSION: In critically ill patients, low pH/bicarbonate and platelet count, greater severity of disease and organ failure are predictors of a low adrenocortical response to ACTH, independent of baseline cortisol values and cortisol binding capacity in blood. These findings may help to delineate relative adrenal insufficiency and suggest that adrenocortical suppression occurs as a result of metabolic acidosis and coagulation disturbances.

Relative adrenal insufficiency: an identifiable entity in nonseptic critically ill patients?

OBJECTIVE: To determine whether relative adrenal insufficiency (RAI) can be identified in nonseptic hypotensive patients in the intensive care unit (ICU). DESIGN: Retrospective study in a medical-surgical ICU of a university hospital. PATIENTS: One hundred and seventy-two nonseptic ICU patients (51% after trauma or surgery), who underwent a short 250 microg ACTH test because of > 6 h hypotension or vasopressor/inotropic therapy. MEASUREMENTS: On the test day, the Simplified Acute Physiology Score II (SAPS II) and Sequential Organ Failure Assessment (SOFA) score were calculated to estimate disease severity. The ICU mortality until day 28 was recorded. Best discriminative levels of baseline cortisol, increases and peaks were established using receiver operating characteristic curves. These and corticosteroid treatment (in n = 112, 65%), among other variables, were examined by multiple logistic regression and Cox proportional hazard regression analyses to find independent predictors of ICU mortality until day 28. RESULTS: ICU mortality until day 28 was 23%. Nonsurvivors had higher SAPS II and SOFA scores. Baseline cortisol levels correlated directly with albumin levels and SAPS II. In the multivariate analyses, a cortisol baseline > 475 nmol/l and cortisol increase < 200 nmol/l predicted mortality, largely dependent on disease severity but independent of albumin levels. Corticosteroid (hydrocortisone) treatment was not associated with an improved outcome, regardless of the ACTH test results. CONCLUSION: In nonseptic hypotensive ICU patients, a low cortisol/ACTH response and treatment with corticosteroids do not contribute to mortality prediction by severity of disease. The data thus argue against RAI identifiable by cortisol/ACTH testing and necessitating corticosteroid substitution treatment in these patients.

Percutaneous dilatational tracheostomy in the ICU: optimal organization, low complication rates, and description of a new complication.

STUDY OBJECTIVES: To assess short-term and long-term complications of bronchoscopy-guided, percutaneous dilatational tracheostomy (PDT) and surgical tracheostomy (ST) and to report a complication of PDT that has not been described previously. DESIGN: Prospective survey. SETTING: University teaching hospital. PATIENTS: Two hundred eleven critically ill patients in our ICU. INTERVENTIONS: PDT was performed in 174 patients, under bronchoscopic guidance in most cases. ST was performed in 40 patients. RESULTS: No procedure-related fatalities occurred during PDT or ST. The incidence of significant complications (eg, procedure-related transfusion of fresh-frozen plasma, RBCs, or platelets, malpositioning or kinking of the tracheal cannula, deterioration of respiratory parameters lasting for > 36 h following the procedure, or stomal infection) in patients undergoing PDT was 4.0% overall and 3.0% when bronchoscopic guidance was used. No cases of paratracheal insertion, pneumothorax, pneumomediastinum, tracheal laceration, or clinically significant tracheal stenosis occurred in patients undergoing PDT. We attribute this low rate of complications to procedural and organizational factors such as bronchoscopic guidance, performance by or supervision of all PDTs by physicians with extensive experience in this procedure, and airway management by physicians who were well-versed in (difficult) airway management. In addition, an ear-nose-throat surgeon participated in the procedure in case conversion of the procedure to an ST should become necessary. We observed a complication that, to our knowledge, has not been reported previously. Five patients developed intermittent respiratory difficulties 2 to 21 days (mean, 8 days) after undergoing PDT. The cause turned out to be the periodic obstruction of the tracheal cannula by hematoma and the swelling of the posterior tracheal wall, which had been caused by intermittent pressure and chafing of the cannula on the tracheal wall. In between the episodes of obstruction, the cannula was open and functioning normally, which made the diagnosis difficult to establish. CONCLUSIONS: Bronchoscopy-assisted PDT is a safe and effective procedure when performed by a team of experienced physicians under controlled circumstances. The intermittent obstruction of the cannula caused by swelling and irritation of the posterior tracheal wall should be considered in patients who develop unexplained paroxysmal respiratory problems some time after undergoing PDT or ST.