Percutaneous tracheostomy: a comprehensive review.

Tracheostomy is a common procedure. It can be done surgically or percutaneously by dilating the stoma using Seldinger technique. Percutaneous tracheostomy (PT) is now routinely performed by surgeons and non-surgeons such as intensivists and anesthesiologists in the intensive care units (ICU) all over the world. Although obesity, emergent tracheostomy, coagulopathy, inability to extend the neck and high ventilator demand (HVD) were initially thought to be a relative contraindication, recent data suggest safety of PT in these patient population. Ultrasound can be helpful in limited cases to identify the neck structure especially in patients with a difficult anatomy. Bronchoscopy during PT can shorten the duration and avoid complications. PT has favorable complication rate, lower infection rate, shorter procedural duration and is cost-effective. Experience with the technique and careful planning is needed to minimize any avoidable potential complication.

Non-anion gap acidosis in asthma: clinical and laboratory features and outcomes for hospitalized patients.

Metabolic acidosis secondary to lactic acidosis may occur in acute, severe asthma and its presence suggests that respiratory muscle fatigue and tissue hypoxia play a major part in the pathogenesis. Non-anion gap metabolic acidosis (NAG acidosis) has also been reported in acute asthma but its impact on the clinical outcome has not been evaluated. The objective of this study was to evaluate the prevalence of NAG acidosis, characterize the laboratory findings, and determine its impact on clinical outcomes. Acid-base and electrolyte status and clinical outcomes were examined over a 1-yr (2005 calendar yr) period in 109 adult patients (38 males, 71 females; age range 21 to 91 yr) hospitalized for asthma exacerbation. The cohort was divided into 3 groups: I. No metabolic acidosis (n = 66), II. Anion gap (AG) acidosis (n = 11), and III. NAG acidosis (n = 32). For each of the groups, laboratory findings were consistent, demonstrating a tendency to hyperchloremia in the NAG acidosis group. One subject in the NAG acidosis group died. NAG acidosis was associated with a statistically significant (p = 0.028) risk of requirement for mechanical ventilation necessitating admission to the Medical Intensive Care Unit (MICU); the odds ratio for intubation for NAG acidosis compared to other groups was 3.92. No difference, however, was detected in overall length of stay (LOS) in hospital for patients with NAG acidosis vs the other groups. NAG metabolic acidosis in acute asthma may be more prevalent than expected and may be associated with more frequent need for mechanical ventilation and admission to an intensive care unit.

Alveolar-arterial oxygen gradient, pneumonia severity index and outcomes in patients hospitalized with community acquired pneumonia.

The alveolar-arterial oxygen gradient (DeltaA-a) provides a useful assessment of ventilation/perfusion (V/Q) abnormalities. The objectives of the present study were to: (i) examine the correlation between the DeltaA-a and the pneumonia severity index (PSI); and (ii) determine whether these measures were comparable in predicting clinical outcomes. The present study was conducted at a 750-bed teaching hospital. It examined a retrospective cohort of 255 patients with community acquired pneumonia (CAP) over a 2 year period. Association between the CAP and DeltaA-a was investigated by regression models and correlation, as well as two logistic models for subjects bifurcated by low-risk/moderate-to-high risk. The decision levels (DL) for both PSI and DeltaA-a were then compared as predictors of both length of stay (LOS) and survival. The correlation between PSI and DeltaA-a was strong (rho = 0.76; P < 0.0001) and was best modelled by a curvilinear relationship. Both logistic models indicated a strong association (P < 0.001) between DeltaA-a and PSI and yielded an optimal DL for the DeltaA-a of < 89 mmHg. Inter-test agreement of DeltaA-a with PSI was 76.9% (kappa = 0.60; 95% confidence interval 0.47-0.72; P < 0.0001). At < 89 mmHg, the odds ratios for LOS were similar to those at PSI = 90 in predicting LOS in the range 3-7 days, inclusive. There was no significant difference in the ability of DeltaA-a and PSI to predict survival for either the low- or high-risk group (P = 0.363 and P = 0.951, respectively). The DeltaA-a correlates well with PSI and performs comparably in predicting two major outcomes in subjects hospitalized with CAP.