Carlos Rodrigo

Outcome of mechanically ventilated patients who require a tracheostomy

Objective:To estimate the prevalence of, the risk factors associated with, and the outcome of tracheostomy in a heterogeneous population of mechanically ventilated patients. Design:Prospective, observational cohort study. Setting:A total of 361 intensive care units from 12 countries. Patients:A cohort of 5,081 patients mechanically ventilated for >12 hrs. Interventions:None. Measurements and Main Results:A total of 546 patients (10.7%) had a tracheostomy during their stay in the intensive care unit. Tracheostomy was performed at a median time of 12 days (interquartile range, 7–17) from the beginning of mechanical ventilation. Variables associated with the performance of tracheostomy were duration of mechanical ventilation, need for reintubation, and neurologic disease as the primary reason of mechanical ventilation. The intensive care unit stay of patients with or without tracheostomy was a median of 21 days (interquartile range, 12–32) vs. 7 days (interquartile range, 4–12; p < .001), respectively, and the hospital stay was a median 36 days (interquartile range, 23–53) vs. 15 days (interquartile range, 8–26; p < .001), respectively. Adjusting by other variables, tracheostomy was independently related with survival in the intensive care unit (odds ratio, 2.22; 95% confidence interval, 1.72–2.86). Mortality in the hospital was similar in both groups (39% vs. 40%, p = .65). Conclusions:Tracheostomy is a common surgical procedure in the intensive care unit that is associated with a lower mortality in the unit but with a longer stay and a similar mortality in the hospital than in patients without tracheostomy.

Continuous vs Intermittent β-Agonists in the Treatment of Acute Adult Asthma: A Systematic Review With Meta-analysis

BACKGROUND Since the late 1980s, there has been considerable clinical and academic interest in the use of continuous aerosolized bronchodilators for the treatment of patients with acute asthma. These studies have suggested that this therapy is safe, is at least as effective as intermittent nebulization, and may be superior to intermittent nebulization in patients with the most severely impaired pulmonary function. OBJECTIVES To determine whether continuous nebulization offered an advantage over intermittent nebulization for the treatment of adults with acute asthma in the emergency department (ED). DESIGN Systematic review of randomized controlled trials of adults with acute asthma. OUTCOMES Change in pulmonary function tests as primary outcome, and admissions to the hospital and side effects as secondary outcomes. RESULTS Six studies including 393 adults with acute asthma were selected. No significant differences were demonstrated between the two delivery methods in terms of pulmonary function measures obtained after 1 h of treatment (standardized mean difference [SMD], -0.15; 95% confidence interval [CI], -0.35 to 0.05) and after 2 to 3 h of treatment (SMD, -0.19; 95% CI, -0.39 to 0.01). No significant heterogeneity was demonstrated (p > 0.5). At the end of treatment, there was a significantly greater decrease in pulse rate when the continuous nebulizer was used (weighted mean difference [WMD], -6.82; 95% CI, -8.67 to -3.90 beats/min; chi(2), 2.55; degrees of freedom [df], 4; p = 0.6). Additionally, the analysis showed a significant decrease of serum potassium concentration with the use of intermittent nebulization (WMD, 0.12; 95% CI, 0.24 to 0.01 mmol/L; chi(2), 0.5; df, 2; p = 0.8). However, this finding was obtained on the analysis of only two trials. Finally, at the end of the study period, no significant differences were identified between patients treated with continuous or intermittent nebulization with respect to hospital admission (relative risk, 0.68; 95% CI, 0.33 to 1.38; chi(2), 2.06; df, 1; p = 0.2). CONCLUSIONS Overall, this review supports the equivalence of continuous and intermittent albuterol nebulization in the treatment of acute adult asthma.

A new index for early prediction of hospitalization in patients with acute asthma

Data from studies using the factor analysis technique have shown that asthma appears to be multidimensional and that most of the subjective and objective measures utilized in the assessment of asthma patients represent a much smaller number of underlying dimensions. Additionally, several investigators have emphasized that evaluation of acute asthma is an ongoing process, as the degree and time course of the response to therapy vary considerably between patients. The aim of this study was to examine the usefulness of the most common clinical and objective measures in the evaluation of acute asthma in the emergency department (ED) for predicting the outcome of acute episodes in adults. In an effort to identify variables that can predict the outcome of patients with acute asthma, 184 adults (age 32.4 +/- 11.6 [mean +/- SD]) (analysis sample) who presented to an ED were studied. The inclusion criteria were: (1) age between 18 and 50 years; (2) a peak expiratory flow rate (PEFR) or forced expiratory volume in the first second (FEV1) below 50% of predicted; and (3) no history of chronic cough or cardiac, hepatic, renal, or other medical disease. All patients were treated with salbutamol delivered with metered-dose inhaler (MDI) into a spacer device in 4 puffs actuated at 10-minute intervals and 500 mg of intravenous hydrocortisone. The multivariate statistical technique of discriminant analysis was utilized to develop the index, and after this, a new sample (n = 91), the validation sample, was studied to validate the index. In the analysis sample 163 patients (89%) were discharged (relapse rate within 7 days = 10%) and 21 (11%) were hospitalized (mean duration of hospital stay = 5.75 +/- 2.81 days). The discriminant analysis identified three independent variables that make the greatest contribution in discriminating between the two groups studied: PEFR variation over baseline, PEFR as percent of predicted, and accessory muscle use, all measured at 30 minutes after the beginning of treatment. A multifactorial index using these three variables presented a sensitivity of 0.86, a specificity of 0.96, a positive predictive value of 0.75, and a negative predictive value of 0.98. The validation sample index sensitivity, specificity, and positive and negative predictive values were 0.83, 0.97, 0.83, and 0.97, respectively. In conclusion, a predictive index has been developed for evaluating patients with asthma who present to an ED. This simple and brief three-item index can facilitate an early decision (30 minutes of treatment) to hospitalize patients with severe asthma.

Clinical InvestigationsAsthmaContinuous vs Intermittent β-Agonists in the Treatment of Acute Adult Asthma: A Systematic Review With Meta-analysis

BACKGROUND Since the late 1980s, there has been considerable clinical and academic interest in the use of continuous aerosolized bronchodilators for the treatment of patients with acute asthma. These studies have suggested that this therapy is safe, is at least as effective as intermittent nebulization, and may be superior to intermittent nebulization in patients with the most severely impaired pulmonary function. OBJECTIVES To determine whether continuous nebulization offered an advantage over intermittent nebulization for the treatment of adults with acute asthma in the emergency department (ED). DESIGN Systematic review of randomized controlled trials of adults with acute asthma. OUTCOMES Change in pulmonary function tests as primary outcome, and admissions to the hospital and side effects as secondary outcomes. RESULTS Six studies including 393 adults with acute asthma were selected. No significant differences were demonstrated between the two delivery methods in terms of pulmonary function measures obtained after 1 h of treatment (standardized mean difference [SMD], -0.15; 95% confidence interval [CI], -0.35 to 0.05) and after 2 to 3 h of treatment (SMD, -0.19; 95% CI, -0.39 to 0.01). No significant heterogeneity was demonstrated (p > 0.5). At the end of treatment, there was a significantly greater decrease in pulse rate when the continuous nebulizer was used (weighted mean difference [WMD], -6.82; 95% CI, -8.67 to -3.90 beats/min; chi(2), 2.55; degrees of freedom [df], 4; p = 0.6). Additionally, the analysis showed a significant decrease of serum potassium concentration with the use of intermittent nebulization (WMD, 0.12; 95% CI, 0.24 to 0.01 mmol/L; chi(2), 0.5; df, 2; p = 0.8). However, this finding was obtained on the analysis of only two trials. Finally, at the end of the study period, no significant differences were identified between patients treated with continuous or intermittent nebulization with respect to hospital admission (relative risk, 0.68; 95% CI, 0.33 to 1.38; chi(2), 2.06; df, 1; p = 0.2). CONCLUSIONS Overall, this review supports the equivalence of continuous and intermittent albuterol nebulization in the treatment of acute adult asthma.

Salbutamol treatment of acute severe asthma in the ED : MDI versus hand-held nebulizer

The objectives of this study were to compare the efficacy of salbutamol delivered by either metered-dose inhaler plus spacer (MDI-spacer) or by wet nebulization (NEB), and to determine the relationships between physiologic responses and plasma salbutamol concentrations. Asthmatic patients presenting to the emergency department (ED) with acute severe asthma (forced expiratory volume in the first second [FEV1] less than 50% of predicted) were enrolled in a randomized, double-blind, parallel-group study. The MDI-spacer group received salbutamol, delivered via MDI into a spacer device, in four puffs actuated in rapid succession at 10-minute intervals (2.4 mg/h). The NEB group was treated with nebulized salbutamol, 1.5 mg, via nebulizer at 15-minute intervals (6 mg/h). Doses were calculated on the basis of the percentage of total dose that reaches the lower airway with both methods. The protocol involved 3 hours of this treatment. Mean peak expiratory flow rate (PEFR) and FEV1 improved significantly over baseline values for both groups (P=.01). However, there were no significant differences between both groups for PEFR and FEV1 at any point studied. The examination of the relationships between cumulative dose of salbutamol and change in FEV1 showed a significant linear relationship (P=.01) for both methods (MDI r=.97; NEB r=.97). The regression equations showed that for every 1 mg of salbutamol by MDI-spacer, 2.5 mg are needed from nebulization to have equal therapeutic response. At the end of treatment, the salbutamol plasma levels were 10.1+/-1.6 ng/ml for the MDI-spacer group and 14.4+/-2.3 ng/ml for the NEB group (P=.0003). Both groups showed a nonsignificant heart rate decrease. A significant group-by-time interaction means that differences between groups increased with time (P=.04). Additionally, the NEB group presented a higher incidence of tremor (P=.03) and anxiety (P=.04), reflecting larger systemic absorption of salbutamol. These data indicate that when doses used are calculated on the basis of the percentage of total drug that reaches the lower airway, there was equivalent bronchodilatation after salbutamol administered by either MDI-spacer or nebulization in patients with acute severe asthma. However, nebulizer therapy produced greater side effects related to the increase in salbutamol absorption and higher plasma level.

Metered dose inhaler salbutamol treatment of asthma in the ED: Comparison of two doses with plasma levels

Two cumulative doses of salbutamol delivered by metered dose inhaler (MDI) with a pear-shaped spacer were compared (400 micrograms vs 600 micrograms at 10-minute intervals). Twenty-two patients (mean age 35.1 +/- 11.1 years) with acute exacerbation of asthma were randomly selected, in a double-blind fashion, to receive salbutamol delivered with MDI into a spacer device in 4 puffs at 10- minute intervals (100 micrograms or 150 micrograms per actuation) during 3 hours (1200 micrograms or 1800 micrograms each 30 minutes). Mean peak expiratory flow rate (PEFR) and forced expiratory volume in the first second (FEV1) improved significantly over baseline values for both groups (P < .001). Nevertheless, there were no significant differences between both groups for PEFR and FEV1 at any time point studied. A significant net reduction of heart rate was observed in the 400 microgram group (P < .01). On the other hand, a significant increase in heart rate was observed in the 600 microgram group (P < .001). The QTc interval did not show a significant prolongation, and the two groups presented moderate decreases of serum potassium levels. There was a significant dose-related increase (P = .027) in Sao2. Additionally, the 600 microgram group generated a serum glucose level increase from 0.85 +/- 0.12 mg/100 mL to 1.04 +/- 0.25 mg/100 mL (P = .02), with a higher incidence in 4 symptoms (tremor, headache, palpitations, and anxiety). These data support the notion that the treatment of acute asthma patients in the emergency department setting with salbutamol, 2.4 mg/h, delivered by MDI and spacer (4 puffs at 10-minute intervals) produces satisfactory bronchodilation, low serum concentration, and minimal extrapulmonary effects. However, an increase of 50% of the dose (600 micrograms at 10-minute intervals) produced a nonsignificant, slightly better therapeutic response but with greater side effects, probably related to higher salbutamol levels.

Subarachnoid hemorrhage following permissive hypercapnia in a patient with severe acute asthma

In this article, we describe a case of a subarachnoid hemorrhage (SAH) in an acute severe asthma patient following mechanical hypoventilation. A 49-year-old man was admitted to an Intensive Care Unit with an acute exacerbation of asthma. After 3 days of mechanical ventilation (hypercapnia and normoxaemia), it was noted that his right pupil was fixed, dilated, and unreactive to light. Computed tomography (CT) scan showed localized SAH within the basilar cisterns and diffuse cerebral swelling. On the fourth day, a new CT scan showed hemorrhage resorption and a cerebral swelling decrease. In the following days, the patients condition continued improving with no detectable neurological deficits. A review of similar published reports showed that all patients performed respiratory acidosis, normoxaemia, and hypercapnia. The most frequent neurological sign was mydriasis, and all subjects showed cerebral edema. Since normoxaemic hypercapnia has been associated with absence, or less cerebral edema, we considered additional factors to explain cerebral edema and intracranial hypertension causes. Thus, intrathoracic pressures due to patients efforts by forcibly exhaling, or during mechanical ventilation, would further increase intracranial pressure by limiting cerebral venous drainage. This case emphasizes the fact that patients with acute severe asthma who have developed profoundly hypercarbic without hypoxia before or during mechanical ventilation, may have raised critical intracranial pressure.

Comparison of salbutamol delivered by nebulizer or metered-dose inhaler with a pear-shaped spacer in acute asthma

Abstract In severe acute asthma, beta-agonist bronchodilator aerosols are the standard first line of treatment. More controversial are the method of delivery and the dose. The purpose of this study was to compare the efficacy of salbutamol delivered by jet nebulizer with that of salbutamol delivered by metered-dose inhaler (MDI) attached to a pearshaped spacer. Doses were calculated on the basis of the percentage of total dose that reaches the lower airway. Ninety-seven patients, ages 18 to 50 years, with acute bronchial asthma previously treated at a hospital emergency room, were enrolled in this randomized, double-blind, placebo-controlled trial. The MDI-spacer group received salbutamol, delivered via MDI into a spacer device, in four puffs actuated in rapid succession (100 μg per actuation) at 10-minute intervals. The nebulized group was treated with nebulized salbutamol, 1.5 mg, via nebulizer at 15-minute intervals. The final mean dose was 5.61 mg for the MDI-spacer group and 11.8 mg for the nebulized group (2:1 dose ratio). Hospitalization was mandatory if the total treatment time exceeded 6 hours. The spirometric values in both groups improved in a similar manner. There were no differences between groups for any variable at any point studied. The duration of emergency room treatment was 2.17 ± 1.69 hours in the MDI-spacer group and 1.94 ± 1.49 hours in the nebulized group ( P = 0.68). The hospital admission rate was similar in both groups (10.2% and 8.33%, respectively; P = 0.95). There were no differences between groups when patients admitted or discharged were examined separately. Similar patterns were seen in patients with severe airway obstruction (forced expiratory volume in 1 second

High-dose MDI salbutamol treatment of asthma in the ED

Beta-adrenergics have long been under special scrutiny because of their potential for cardiotoxicity. To assess the safety of high doses of salbutamol delivered by metered dose inhaler (MDI) with spacer in the emergency department (ED) setting, 11 patients (mean age 33 +/- 12.2 years) with severe acute asthma were studied. All patients were treated with 400 micrograms of salbutamol at 10-minute intervals for 3 hours (1,200 micrograms each 30 minutes or 7,200 micrograms at 180 minutes. There were dose-related significant increases in forced expiratory volume in the first second (FEV1) and peak expiratory flow (PEF) (P < .01), with a net mean increase of 90.4% and 80.1%, respectively. A significant (P < .01) reduction of heart rate was observed with treatment. At the end of protocol, reductions ranged from 7 beats/min to 35 beats/min (mean decrease 10.6 +/- 10.5 beats/min). There was no prolongation in the QTc interval. Mean baseline serum potassium was 4.23 +/- 0.53 mmol/L and decreased nonsignificantly after treatment to 3.99 +/- 0.62 mmol/L. Only 4 patients showed net decreases. There were no significant changes in oxygen saturation and plasma glucose. The mean end-treatment salbutamol level was 10.0 +/- 1.67 ng/mL. These data support the notion that treatment of acute asthma patients in the ED with 2.4 mg salbutamol per hour delivered by MDI and spacer produce satisfactory bronchodilation, low serum concentration, and minimal extrapulmonary effects.

Aerosol and inhaled therapy in treatment of acute adult airway obstruction in the emergency department.

This article reviews the aerosol therapy and inhalotherapy in the nonintubated adult patient with acute severe asthma in the emergency department. Factors influencing lower respiratory deposition of aerosols are summarized. The use of inhaled beta2-adrenergic agonists, anticholinergic drugs, corticosteroids, and heliox are discussed.