Facial mask noninvasive mechanical ventilation reduces the incidence of nosocomial pneumonia. A prospective epidemiological survey from a single ICU

OBJECTIVE: To evaluate the impact of noninvasive positive pressure mechanical ventilation (NPPV) on ventilator-associated pneumonia (VAP). DESIGN: Prospective observational study. SETTING: Medical intensive care unit (ICU) of a university teaching hospital. PATIENTS: Cohort of 320 consecutive patients staying in the ICU more than 2 days and mechanically ventilated for > or = 1 day. MEASUREMENTS AND RESULTS: VAP was diagnosed when, satisfying classical clinical and radiological criteria, fiberoptic bronchoalveolar lavage and/or protected specimen brush grew > or = 10(4) and > or = 10(3) CFU/ml, respectively, of at least one microorganism. Patients were classified into four subgroups according to the way in which mechanical ventilation was delivered: NPPV then tracheal intubation (TI) (n = 38), TI then NPPV (n = 23), TI only (n = 199), and NPPV only (n = 60). Occurrence of VAP was estimated by incidence rate and density of incidence. Risk factors for VAP were assessed by logistic regression analysis. Twenty-seven patients had 28 episodes of VAP. The incidence rates for patients with VAP were 18% in NPPV-TI, 22% in TI-NPPV, 8% in TI, and 0% in NPPV (p < 0.0001). The density of incidence of VAP was 0.85 per 100 days of TI and 0.16 per 100 days of NPPV (p = 0.04). Logistic regression showed that length of ICU stay and ventilatory support were associated with VAP. CONCLUSIONS: There is a significantly lower incidence of VAP associated with NPPV compared to tracheal intubation. This is mainly explained by differences in patient severity and risk exposure.     

Study of the use of noninvasive ventilation of the lungs in acute respiratory insufficiency due exacerbation of chronic obstructive pulmonary disease

Noninvasive positive pressure ventilation (NPPV) is a life-saving procedure in acute respiratory failure (ARF), but its technique is not yet in routine use in many respiratory centers. We carried out a prospective randomized study comparing the combination of NPPV with conventional therapy (oxygen, bronchodilators, steroids, and theophylline) with conventional therapy alone in patients with acute respiratory failure caused by exacerbation of chronic obstructive pulmonary disease (COPD). A total of 58 patients were recruited from a large group of patients admitted to our hospital between September 1995 and March 1997. Twenty-nine patients were randomly assigned to the NPPV group and 29 to the conventional (non-NPPV) group. The patients were matched for demographic and physiological norm values (mean age 63.4 +/- 5.5 vs. 66.2 +/- 7.1 years, mean FEV1 0.68 +/- 0.15 vs. 0.74 +/- 0.16 L, PaO2 51.4 +/- 6.8 vs. 52.3 +/- 6.5 mm Hg, PaCO2 63.4 +/- 10.9 vs. 64.9 +/- 9.7 mm Hg, and pH 7.28 +/- 0.07 vs. 7.26 +/- 0.06). The outcome end points were needed for endotracheal intubation, length of hospital stay, and incidence of complications. NPPV was administered using BiPAP ventilatory device (Respironics, Inc.) by spontaneous and spontaneous/timed modes via nasal and facial masks. The mean time of NPPV was 29 +/- 25 h. Three patients refused from NPPV because of intolerance of mask or ventilation procedure. Two of them were eventually intubated and one of them died. In patients administered NPPV, we observed a significant rise of pH and fall of PaCO2 after 1 h of ventilation, in contrast to the non-NPPV group (7.34 +/ 0.09 vs. 7.21 +/- 0.08, p < 0.05; 53.2 +/- 10.7 vs. 71.4 +/- 10.2 mm Hg, p < 0.01, respectively). The need in intubation was lower in the NPPV group as compared to the reference group (12 vs. 28%, p = 0.18), mortality rate was higher in the non-NPPV group (31 vs. 8%, p = 0.03), and hospital stay was shorter in NPPV patients (26 +/- 7 vs. 34 +/- 10 days). The incidence of complications was lower in the NPPV group, they were less significant, and did not involve discontinuation of ventilation. Hence, NPPV is a first-line therapy in patients with ARF caused by COPD exacerbation, due to obvious advantages over conventional methods of treatment.     

Comparison of noninvasive positive pressure ventilation with standard medical therapy in hypercapnic acute respiratory failure

STUDY OBJECTIVE: To compare the efficacy of standard medical therapy (ST) and noninvasive mechanical ventilation additional to standard medical therapy in hypercapnic acute respiratory failure (HARF). DESIGN: Single center, prospective, randomized, controlled study. SETTING: Pulmonary medicine directed critical care unit in a university hospital. PATIENTS: Between March 1993 and November 1996, 30 HARF patients were randomized to receive ST or noninvasive positive pressure ventilation (NPPV) in addition to ST. INTERVENTIONS: NPPV was given with an air-cushioned face via a mechanical ventilator (Puritan Bennett 7200) with initial setting of 5 cm H2O continuous positive airway pressure and 15 cm H2O pressure support. RESULTS: At the time of randomization, patients in the ST group had (mean+/-SD) PaO2 of 54+/-13 mm Hg, PaCO2 of 67+/-11 mm Hg, pH of 7.28+/-0.02, and respiratory rate of 35.0+/-5.8 breaths/min. Patients in the NPPV group had PaO2 of 55+/-14, PaCO2 of 69+/-15, pH of 7.27+/-0.07, and respiratory rate of 34.0+/-8.1 breaths/min. With ST, there was significant improvement of only respiratory rate (p < 0.05). However, with NPPV, PaO2 (p < 0.001), PaCO2 (p < 0.001), pH (p < 0.001), and respiratory rate (p < 0.001) improved significantly compared with baseline. Six hours after randomization, pH (p < 0.01) and respiratory rate (p < 0.01) in NPPV patients were significantly better than with ST. Hospital stay for NPPV vs ST patients was, respectively, 11.7+/-3.5 and 14.6+/-4.7 days (p < 0.05). One patient in the NPPV group required invasive mechanical ventilation. The conditions of six patients in the ST group deteriorated and they were switched to NPPV; this was successful in four patients, two failures were invasively ventilated. CONCLUSION: This study suggests that early application of NPPV in HARF patients facilitates improvement, decreases need for invasive mechanical ventilation, and decreases the duration of hospitalization.     

The effect of positive pressure airway support on mortality and the need for intubation in cardiogenic pulmonary edema: a systematic review

OBJECTIVE: To critically appraise and summarize the trials examining the addition of continuous positive airway pressure (CPAP) or noninvasive positive pressure ventilation (NPPV) to standard therapy on hospital mortality, need for endotracheal intubation, and predischarge left ventricular function in patients admitted to the hospital with cardiogenic pulmonary edema with gas exchange abnormalities. DATA SOURCES: We searched MEDLINE (1983 to June 1997) and bibliographies of all selected articles and review articles. We also reviewed the abstracts from the proceedings of relevant meetings from 1985 to 1997. STUDY SELECTION: (1) Population: patients presenting to hospital with cardiogenic pulmonary edema; (2) intervention: one of the following three: (a) the use of CPAP and standard medical therapy vs standard medical therapy alone; (b) the use of NPPV and standard medical therapy vs standard medical therapy alone; and (c) the use of NPPV and standard therapy vs CPAP and standard therapy; (3) outcome: hospital survival, need for endotracheal intubation, or predischarge left ventricular dysfunction; and (4) study design: randomized controlled trial (RCT); if there were fewer than two RCTs, other study designs were included. DATA EXTRACTION: Two authors independently extracted data and evaluated the methodologic quality of the studies. DATA SYNTHESIS: CPAP was associated with a decrease in need for intubation (risk difference, -26%, 95% confidence intervals, -13 to -38%) and a trend to a decrease in hospital mortality (risk difference, -6.6%; +3 to -16%) compared with standard therapy alone. There was insufficient evidence to comment on the effectiveness of NPPV either compared with standard therapy or CPAP and standard therapy. Evidence was also lacking on the potential for either intervention to cause harm. CONCLUSIONS: A modest amount of favorable experimental evidence exists to support the use of CPAP in patients with cardiogenic pulmonary edema. CPAP appears to decrease intubation rates and data suggest a trend toward a decrease in mortality, although the potential for harm has not been excluded. The role of NPPV in this setting requires further study before it can be widely recommended.     

Noninvasive positive pressure ventilation via face mask. First-line intervention in patients with acute hypercapnic and hypoxemic respiratory failure

OBJECTIVES: We have previously reported our experience with noninvasive positive pressure ventilation (NPPV) via face mask in a small group of selected patients with acute respiratory failure (ARF). NPPV was frequently effective (70% success rate) in correcting gas exchange abnormalities and in avoiding endotracheal intubation (ETI); NPPV also had a low rate of complications. We have evaluated the clinical application of NPPV as first-line intervention in patients with hypercapnic and short-term hypoxemic ARF. A dedicated respiratory therapist conducted an educational program with physicians-in-training rotating through the medical ICUs of a university medical center and supervised implementation of a simplified management protocol. Over 24 months, 164 patients with heterogeneous forms of ARF received NPPV. We report on the effectiveness of NPPV in correcting gas exchange abnormalities, in avoiding ETI, and associated complications, in different conditions precipitating ARF. PATIENT POPULATION: One hundred fifty-eight patients completed the study. Forty-one had hypoxemic ARF, 52 had hypercapnic ARF, 22 had hypercapnic acute respiratory insufficiency (ARI), 17 had other forms of ARF, and 26 with advanced illness had ARF and refused intubation. Twenty-five percent of the patients developed ARF after extubation. INTERVENTION: Mechanical ventilation was delivered via a face mask. Initial ventilatory settings were continuous positive airway pressure (CPAP) mode, 5 cm H2O, with pressure support ventilation of 10 to 20 cm H2O titrated to achieve a respiratory rate less than 25 breaths/min and an exhaled tidal volume of 7 mL/kg or more. Ventilator settings were adjusted following arterial blood gases (ABG) results. RESULTS: The mean duration of NPPV was 25 +/- 24 h. When the 26 patients with advanced illness are excluded, NPPV was effective in improving or correcting gas exchange abnormalities in 105 patients (80%) and avoiding ETI in 86 (65%). Failure to improve ABG values was the reason for ETI in 20 of 46 (43%). The overall average predicted and actual mortality were 32% and 16%, respectively. Survival was 93% in non-intubated patients and 79% in intubated patients. NPPV was effective in lessening dyspnea throughout treatment in all but seven patients. Complications developed in 24 patients (16%). In patients with hypercapnic ARF, nonresponders had a higher PaCO2 at entrance (91.5 +/- 4.2 vs 80 +/- 1.5; p < 0.01). In patients with hypercapnic ARF and ARI, arterial blood gases response (pH and PaCO2) within 2 h of NPPV predicted success (p < 0.0001). None of the entrance parameters predicted need for ETI. CONCLUSIONS: We conclude that application of NPPV in clinical practice is an effective and safe alternative to ETI in many hemodynamically stable patients with hypercapnic ARF and in those with hypoxemic ARF in whom the clinical condition can be readily reversed in 48 to 72 h. An educational and supervision program is essential to successfully implement this form of therapy.     

Effects of support pressure ventilation with facial mask in patients with chronic respiratory failure in acute decompensation

BACKGROUND: In previous nonrandomized studies the efficacy of ventilation with back up pressure with face mask (BUPM) in the treatment of patients with chronic obstructive pulmonary disease (COPD) in acute decompensation has been demonstrated. This study analyzes the acute effects and the clinical efficacy of BUPM in a group of patients with COPD in acute respiratory failure comparing the same with conventional therapy (CONV). METHODS: A prospective randomized study including patients with COPD in acute decompensation was carried out comparing treatment with BUPM (n = 9) with CONV treatment (n = 9). Back up pressure was fixed at 20 cmH2O. Acute gasometric effects were analyzed as well as the need for intratracheal intubation, mortality and hospital stay. RESULTS: No clinical or gasometric differences were found between either group of patients upon admission. Only the patients of the BUPM group presented a significant improvement from gaseous exchange and respiratory frequency from the first hour of treatment. Three of the nine patients (33%) of the BUPM group and nine of the CONV group of patients (100%) required intubation and mechanical ventilation (p = 0.001). CONCLUSIONS: Back up pressure face mask is the technique of choice in patients with chronic obstructive pulmonary disease in acute decompensation given that this technique leads to a rapid and significant improvement of gaseous exchange and avoids the need for intubation and mechanical ventilation in most of these patients.     

Non-invasive nasal ventilation in a a case of hypercapnic coma

Noninvasive positive pressure ventilation (NPPV) via nasal mask is well known to be effective in the treatment of acute respiratory failure (ARF) secondary to chronic obstructive pulmonary disease (COPD). A case of ARF with hypercapnic coma due to exacerbation of COPD is described. Six hours of conservative therapy with oxygen and medical treatment did not show any result. As endotracheal intubation (ET) was avoided on the basis of advanced age, poor life expectancy of the patient and family wish, NPPV was set up using a pressure triggered ventilator. After 61 hours of uninterrupted NPPV, the acid-base alteration and the lethargic status was fully reversed. The conclusions is drawn that NPPV may be useful also in the treatment of patients affected by severe decompensated hypercapnic respiratory failure in whom ET is not indicated.     

A comparison of noninvasive positive-pressure ventilation and conventional mechanical ventilation in patients with acute respiratory failure

BACKGROUND AND METHODS: The role of noninvasive positive-pressure ventilation delivered through a face mask in patients with acute respiratory failure is uncertain. We conducted a prospective, randomized trial of noninvasive positive-pressure ventilation as compared with endotracheal intubation with conventional mechanical ventilation in 64 patients with hypoxemic acute respiratory failure who required mechanical ventilation. RESULTS: Within the first hour of ventilation, 20 of 32 patients (62 percent) in the noninvasive-ventilation group and 15 of 32 (47 percent) in the conventional-ventilation group had an improved ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO2:FiO2) (P=0.21). Ten patients in the noninvasive-ventilation group subsequently required endotracheal intubation. Seventeen patients in the conventional-ventilation group (53 percent) and 23 in the noninvasive-ventilation group (72 percent) survived their stay in the intensive care unit (odds ratio, 0.4; 95 percent confidence interval, 0.1 to 1.4; P=0.19); 16 patients in the conventional-ventilation group and 22 patients in the noninvasive-ventilation group were discharged from the hospital. More patients in the conventional-ventilation group had serious complications (66 percent vs. 38 percent, P=0.02) and had pneumonia or sinusitis related to the endotracheal tube (31 percent vs. 3 percent, P=0.003). Among the survivors, patients in the noninvasive-ventilation group had shorter periods of ventilation (P=0.006) and shorter stays in the intensive care unit (P=0.002). CONCLUSIONS: In patients with acute respiratory failure, noninvasive ventilation was as effective as conventional ventilation in improving gas exchange and was associated with fewer serious complications and shorter stays in the intensive care unit.     

Respiratory failure based on pulmonary tuberculosis sequelae and its management

According to the complexity of pathological change of pulmonary tuberculosis sequelae (TB seq), on which respiratory failure based shows the higher incidence of marked degree of hypoxemia and hypercapnia than that based on chronic pulmonary emphysema (CPE). In TB seq, pulmonary artery mean pressure is higher, nocturnal oxyhemoglobin desaturation is much lower than in CPE. Also hypoxemia on exercise is lower, and oxygen inhalation for this hypoxemia is more effective than in CPE. The most effective therapy is continuous oxygen therapy. Home oxygen therapy has improved the prognosis and quality of life (QOL) of patients with respiratory failure based on TB seq. Artificial positive pressure ventilation (TIPPV) with intubation or tracheotomy is carried out for patients with severe hypercapnia and respiratory acidosis. Recently, early application of nasal mask ventilation (NPPV) on patients with TB seq has prohibited acute exacerbation of chronic respiratory failure. And also for patients with severe hypercapnia, NPPV with BIPAP method is effective for their QOL. Comprehensive respiratory rehabilitation is also successfully applied for their management.     

Effect of side chain location in (2-aminoethyl)-aminomethyl-2-phenylquinolines as antitumor agents

New equipment facilitating the use of spontaneous ventilation with positive expiratory pressure (PEP) has become available in France since January 1996. This technique was applied in 38 patients with severe cardiogenic pulmonary oedema and persistent respiratory distress despite high flow classical oxygen therapy and standard treatment. After 1 hour of ventilation with a flow of 220 l/min of 100% oxygen with an average PEP of 7.7 cm H20, a significant improvement of clinical (heart and respiratory rate) and biological parameters (arterial gases) was observed. There were no side effects. Four patients died during the hospital period and only 1 was intubated. Spontaneous ventilation with PEP is a simple technique for coronary care units and, compared with conventional oxygen therapy, it rapidly improves arterial oxygenation, reduces respiratory work and improves conditions of cardiac load. Acute severe cardiogenic pulmonary oedema seems to be an indication of choice, especially in the elderly, where it may help avoid an often controversial intubation.     

Noninvasive mechanical ventilation in a patient with respiratory failure after hematopoietic progenitor transplantation

Respiratory failure requiring orotracheal intubation (OTI) and mechanical ventilation (MV) is almost always a fatal complication in patients who undergo hematopoietic progenitor transplantation (HPT). We present the case of a woman who suffered respiratory failure with bilateral infiltrates on a chest X-ray taken on day +14 following autologous bone marrow transplantation. We managed the patient satisfactorily with noninvasive ventilation, avoiding OTI. We believe that patients with non-progressive pulmonary lesions and without multiple system organ failure, may be correctly managed with noninvasive positive-pressure ventilation (NPPV).     

Non-invasive modalities of positive pressure ventilation improve the outcome of acute exacerbations in COLD patients

OBJECTIVE: 1) To compare the clinical usefulness of both non-invasive pressure support ventilation (NPSV) and non-invasive intermittent positive pressure ventilation in assist-control (A/C) mode (NIPPV) in chronic obstructive lung disease (COLD) patients with acute hypercapnic respiratory failure: 2) to compare retrospectively the usefulness of non-invasive mechanical ventilation (NMV) with standard medical therapy alone. DESIGN: Prospective randomized retrospective study. SETTING: 2 Respiratory intermediate intensive units. PATIENTS: 29 COLD patients (age: 62 +/- 8 years) with chronic respiratory failure were hospitalized in a department for rehabilitation during acute relapses of their disease. They were transferred to our intermediate intensive care unit (IICU) and submitted randomly to either NPSV (16 patients) or NIPPV (13 patients). MEASUREMENTS AND RESULTS: Blood gas analysis, dynamic flows, clinical variables, success rate, time of ventilation, side effects and subjective score of compliance to therapy. Therapy was considered successful when endotracheal intubation was avoided and patients were returned to their condition prior to exacerbation. No statistically significant difference was found between NPSV and NIPPV in success rate (NPSV 87.5%; NIPPV 77%) or in time of ventilation (NPSV: 69 +/- 49; NIPPV: 57 +/- 49 h). A better compliance to non-invasive mechanical ventilation (NMV) was found in NPSV patients than in NIPPV patients; side effects were observed less frequently in the NPSV group. Comparison of the success rate of NMV was retrospectively performed with 35 control COLD patients with chronic respiratory insufficiency who had undergone an acute relapse of their disease in the 2 years preceding the institution of the IICU and had been treated with oxygen and medical therapy alone. Patients submitted to NMV showed a greater success rate than control (82 versus 54%) after a period of ventilation ranging from 4-216 h. CONCLUSION: Non-invasive mechanical ventilation performed either by NPSV or NIPPV may improve the outcome of acute exacerbations of COLD, as compared to medical therapy alone. NPSV seems to be more acceptable to patients in comparison with NIPPV.     

A comparison of awake versus paralyzed tracheal intubation for infants with pyloric stenosis

This prospective, nonrandomized, observational study of 76 infants with pyloric stenosis was conducted at an academic children's hospital and compared awake versus paralyzed tracheal intubation in terms of successful first attempt rate, intubation time, heart rate (HR) and arterial hemoglobin oxygen saturation (SpO2) changes, and complications. Three groups were determined by intubation method: awake (A) with an oxygen-insufflating laryngoscope, after rapid-sequence induction (R), or after modified rapid-sequence induction (M) including ventilation through cricoid pressure. Successful first attempt intubation rate was 64% for Group A versus 87% for paralyzed Groups R and M (P = 0.028). Median intubation time was 63 s in Group A versus 34 s in Groups R and M (P = 0.004). Transient, mild decreases in mean HR and SpO2 and incidences of significant bradycardia and decreased SpO2 did not vary by group. Complications, including bronchial or esophageal intubation, emesis, and oropharyngeal trauma, were few. Senior anesthesiologists intervened in four tracheal intubations. We advocate anesthetized, paralyzed tracheal intubation because struggling with conscious infants takes longer, often requires multiple attempts, and prevents neither bradycardia nor decreased SpO2. After induction, additional mask ventilation with O2 confers no advantage over immediate tracheal intubation in preserving SpO2. Implications: In our children's hospital, awake tracheal intubation was not superior to anesthetized, paralyzed intubation in maintaining adequate oxygenation and heart rate or in reducing complications, and should be abandoned in favor of the latter technique for routine anesthetic management of otherwise healthy infants with pyloric stenosis.     

The use of continuous i.v. sedation is associated with prolongation of mechanical ventilation

STUDY OBJECTIVE: To determine whether the use of continuous i.v. sedation is associated with prolongation of the duration of mechanical ventilation. DESIGN: Prospective observational cohort study. SETTING: The medical ICU of Barnes-Jewish Hospital, a university-affiliated urban teaching hospital. PATIENTS: Two hundred forty-two consecutive ICU patients requiring mechanical ventilation. INTERVENTIONS: Patient surveillance and data collection. MEASUREMENTS AND RESULTS: The primary outcome measure was the duration of mechanical ventilation. Secondary outcome measures included ICU and hospital lengths of stay, hospital mortality, and acquired organ system derangements. A total of 93 (38.4%) mechanically ventilated patients received continuous i.v. sedation while 149 (61.6%) patients received either bolus administration of i.v. sedation (n=64) or no i.v. sedation (n=85) following intubation. The duration of mechanical ventilation was significantly longer for patients receiving continuous i.v. sedation compared with patients not receiving continuous i.v. sedation (185+/-190 h vs 55.6+/-75.6 h; p<0.001). Similarly, the lengths of intensive care (13.5+/-33.7 days vs 4.8+/-4.1 days; p<0.001) and hospitalization (21.0+/-25.1 days vs 12.8+/-14.1 days; p<0.001) were statistically longer among patients receiving continuous i.v. sedation. Multiple linear regression analysis, adjusting for age, gender, severity of illness, mortality, indication for mechanical ventilation, use of chemical paralysis, presence of a tracheostomy, and the number of acquired organ system derangements, found the adjusted duration of mechanical ventilation to be significantly longer for patients receiving continuous i.v. sedation compared with patients who did not receive continuous i.v. sedation (148 h [95% confidence interval: 121, 175 h] vs 78.7 h [95% confidence interval: 68.9, 88.6 h]; p<0.001). CONCLUSION: We conclude from these preliminary observational data that the use of continuous i.v. sedation may be associated with the prolongation of mechanical ventilation. This study suggests that strategies targeted at reducing the use of continuous i.v. sedation could shorten the duration of mechanical ventilation for some patients. Prospective randomized clinical trials, using well-designed sedation guidelines and protocols, are required to determine whether patient-specific outcomes (eg, duration of mechanical ventilation, patient comfort) can be improved compared with conventional sedation practices.     

Airway occlusion pressure at 0.1 s (P0.1) after extubation: an early indicator of postextubation hypercapnic respiratory insufficiency

OBJECTIVE: To examine variables associated with postextubation respiratory distress in chronic obstructive pulmonary disease (COPD) patients. DESIGN: Prospective, clinical investigation. SETTING: Intensive care unit of a university hospital. PATIENTS: Forty COPD patients, considered ready for extubation. MEASUREMENTS AND MAIN RESULTS: We recorded, from the digital display of a standard ventilator, breathing frequency (f), tidal volume (VT) and f/VT for the respiratory pattern, airway occlusion pressure at 0.1 s (P0.1) for the respiratory drive and measured blood gases: i) before extubation, following 30 min of a 6 cm H2O pressure support (PS) ventilation trial, ii) 1 h after extubation, at the 30th min of a face mask 4 cm H2O PS ventilation trial. According to the weaning outcome, the patients were divided into two groups: respiratory distress, and non-respiratory distress within 72 h of the discontinuation of mechanical ventilation. The respiratory distress was defined as the combination of f more than 25 breaths/min, an increase in PaCO2 of at least 20% compared with the value measured after extubation, and pH lower than 7.35. We determined whether those patients who developed respiratory distress after extubation differed from those who did not. Respiratory pattern data and arterial blood gases recorded, either before or after extubation, and P0.1 recorded before extubation, were inadequate to differentiate the two groups. Only P0.1 recorded 1 h after the discontinuation of mechanical ventilation differentiated the patients who developed respiratory distress from those who did not (4.2+/-0.9 vs 1.8+/-0.8, p < 0.01). CONCLUSIONS: P0.1 recorded after extubation may be a good indicator of postextubation respiratory distress. Measuring P0.1 and/or the analysis of the evolution of this parameter could facilitate decisions during the period following extubation.     

Noninvasive pressure support ventilation in COPD patients with postextubation hypercapnic respiratory insufficiency

Patients with chronic obstructive pulmonary disease (COPD) who have been intubated and mechanically ventilated may prove difficult to wean. Noninvasive ventilation may be used in an attempt to avoid new endotracheal intubation. The efficacy of administration of noninvasive pressure support ventilation was evaluated in 30 COPD patients with postextubation hypercapnic respiratory insufficiency, compared with 30 historically matched control patients who were treated conventionally. Patients were included in the study if, within 72 h postextubation, they presented with respiratory distress, defined as the combination of a respiratory frequency >25 breaths x min(-1), an increase in the arterial carbon dioxide tension (Pa,CO2) of at least 20% compared with the value measured after extubation, and a pH <7.35. Noninvasive pressure support ventilation was effective in correcting gas exchange abnormalities. The use of noninvasive ventilation significantly reduced the need for endotracheal intubation: 20 of the 30 patients (67%) in the control group required endotracheal intubation, compared with only six of the 30 patients (20%) in the noninvasive-ventilation group (p<0.001). In-hospital mortality was not significantly different between the two groups, but the mean duration of ventilatory assistance for the treatment of the postextubation distress, and the length of intensive care unit stay related to this event, were both significantly shortened by noninvasive ventilation (p<0.01). In conclusion, noninvasive ventilation may be used in the management of patients with chronic obstructive pulmonary disease and postextubation hypercapnic respiratory insufficiency.     

Wortmannin-sensitive activation of p70S6-kinase and MAP-kinase by the G protein-coupled receptor, G/CCKB

OBJECTIVE: To determine whether emergency rigid bronchoscopic intervention, including Nd-YAG laser resection or stenting, immediately affected the need for continued mechanical ventilation or intensive care level of support in critically ill patients with acute respiratory failure from malignant or benign central airways obstruction. DESIGN: Retrospective review of medical records of all patients with acute respiratory failure and malignant or benign tracheobronchial obstruction necessitating intubation, mechanical ventilation, or hospitalization in the ICU prior to referral for therapeutic bronchoscopy. SETTING: University of California San Diego, a tertiary care institution specialized in airway management. PATIENTS: Medical records of 32 patients with malignant or benign central airways obstruction requiring admission to the ICU prior to rigid bronchoscopic intervention between January 1994 and April 1996. INTERVENTIONS: Emergent rigid bronchoscopy with dilatation, Nd-YAG laser resection, or silicone stent insertion performed in the operating room under general anesthesia. RESULTS: Thirty-two patients with central airways obstruction requiring emergent hospitalization in the ICU were referred for therapeutic rigid bronchoscopy. Airway strictures were caused by benign disease in 18 patients, and by primary bronchogenic lung cancer in 14. Of the 19 patients who were mechanically ventilated, bronchoscopic intervention allowed immediate discontinuation of mechanical ventilation in 10 (52.6%). Twenty-five patients had indwelling artificial airways (12 endotracheal tubes, 13 tracheotomy tubes). Two, however, were considered tracheotomy-dependent because of neuromuscular disease. Of the remaining 23 patients, immediate extubation or decannulation was possible in seven (30.4%). Of seven patients with no indwelling airway, five (71.4%) were immediately transferred to a lower level of care after intervention. Of the 32 total patients, 20 (62.5%) were immediately transferred to a lower level of care immediately after intervention. CONCLUSIONS: Emergency laser resection or stent insertion can favorably affect health-care utilization in patients with acute respiratory distress from central airways obstruction. Treatment may be lifesaving and allows successful withdrawal from mechanical ventilation, hospitalization in a lower level of care environment, relief of symptoms, and extended survival in critically ill patients. In patients with regionally advanced cancer, the palliative nature of this procedure postpones death by respiratory distress and may prompt consideration for institution of conservative comfort measures to reduce patient suffering.     

Noninvasive ventilation in intensive care

Non-invasive ventilation has been in use for many years to provide long-term home ventilatory support to patients with chronic respiratory failure. In recent years, it has emerged on the intensive care scene as a means of avoiding intubation in acute respiratory failure. The results of several studies indicate that such an approach can lead to a reduction in mortality and duration of hospital stay compared to conventional mechanical ventilation with endotracheal intubation. The purpose of this article is to explore the various ventilatory techniques available, the choice of respirator and ventilatory mode in various clinical conditions, and to discuss some of the logistics involved in the optimal use of this technique.     

Efficacy of dead-space washout in mechanically ventilated premature newborns

The prosthetic dead space makes a significant contribution to the total dead space in low-birth-weight premature newborns receiving artificial ventilation in response to respiratory distress. Use of an endotracheal tube with capillaries molded into the tube wall enables washout of the dead space without insertion of a tracheal catheter. In 10 premature newborns (mean gestational age, 27.5 +/- 2.2 wk; mean weight, 890 +/- 260 g) receiving continuous positive-pressure ventilation (Paw = 12.7 +/- 1.8 cm H2O; FIO2 = 39 +/- 17%), tracheal gas insufflation (TGI) for CO2 washout was conducted using this technique. The flow of tracheal insufflation (0.5 L/min) was derived from the inspiratory line of the ventilator circuit and blown into the trachea. Intratracheal pressures showed little or no TGI-related modification ( < 1 cm H2O). A control system enabled TGI discontinuation in the event of a pressure rise. At constant ventilation pressure, PaCO2 decreased by 12.1 +/- 5.9 mm Hg (delta PaCO2 = -26 +/- 12%) under TGI, whereas PaO2 remained unchanged. While maintaining PaCO2 constant, peak inspiratory pressure (PIP) was decreased by 5.4 +/- 1.7 cm H2O (delta PIP = -22.0 +/- 8.3%). TGI showed immediate efficacy (PCO2 reduction of at least 5 mm Hg) in nine of the 10 newborns who then received chronic TGI (14 to 138 h). TGI appears to be an effective method, suitable for long-term clinical application, enabling a reduction in the aggressive nature of conventional ventilation.     

Initial resuscitation of closed thoracic trauma

Blunt thoracic trauma are frequent and often severe. Their management is improved in the prehospital settings by the involvement of a medical team, and the admission in a specialized trauma center. Diagnostic and therapeutic steps are closely linked. They are based on the stabilization of life threatening problems and the appropriate use of recent advances in medical imaging. Endotracheal intubation and mechanical ventilation are indicated for respiratory distress. Immediate surgical management is mandatory for an hypovolemic shock related to massive hemothorax. On the contrary, multiple ribs fractures and flail chest without major pulmonary contusion are managed with regional analgesia allowing effective physiotherapy and avoiding the infectious complications related to prolonged mechanical ventilation.