Monitoring during mechanical ventilation

Approximately half of the patients admitted to an ICU are admitted for the purposes of monitoring rather than interventional therapy. In the last decade, significant technologic advances have enhanced monitoring capacities, and the understanding of the pathophysiology of respiratory failure has improved pari passu, allowing clinicians to employ monitors in a more intelligent manner. This article deals with new developments in arterial blood gas monitoring, pulse oximetry, capnometry, and monitoring of neuromuscular function and pulmonary mechanics, emphasizing issues most relevant to mechanical ventilation.     

A tube in the pharynx for emergency ventilation

BACKGROUND: If the endotracheal placement of a nasal advanced tube fails, ventilation via this tube could bridge the time until a fibreoptic bronchoscope is available. This study investigates the efficiency of ventilation via a tube resting with its tip in the pharynx near the glottis. METHODS: In 20 patients respiratory data during ventilation via a pharyngeally placed tube were recorded by means of pulse oximetry, capnometry and side-stream spirometry. Results were compared with those measured previously in the same patients during conventional facemask ventilation. RESULTS: Oxygen saturation and end-tidal carbon dioxide concentration remained unchanged using ventilation via facemask (SO2 98.5 +/- 0.9%, FECO2 4.5 +/- 0.7 vol%) or pharyngeal tube (SO2 98.6 +/- 0.7%, FECO2 4.8 +/- 0.4 vol%). No significant differences were found between the two groups with regard to peak airway pressure, tidal volume leakage, compliance and resistance of the respiratory system. CONCLUSIONS: Our results suggest an effective ventilation and oxygenation via a tube placed with its tip in the pharynx. This technique may be helpful during difficult and prolonged nasal intubation.     

PSA screening--current controversy

OBJECTIVE: To evaluate treatment with noninvasive ventilation (NIV) by nasal mask as an alternative to endotracheal intubation and conventional mechanical ventilation in patients with hematologic malignancies complicated by acute respiratory failure to decrease the risk of hemorrhagic complications and increase clinical tolerance. DESIGN: Prospective clinical study. SETTING: Hematologic and general intensive care unit (ICU), University of Rome "La Sapienza". PATIENTS: 16 consecutive patients with acute respiratory failure complicating hematologic malignancies. INTERVENTIONS: NIV was delivered via nasal mask by means of a BiPAP ventilator (Respironics, USA); we evaluated the effects on blood gases, respiratory rate, and hemodynamics along with tolerance, complications, and outcome. MEASUREMENTS AND RESULTS: 15 of the 16 patients showed a significant improvement in blood gases and respiratory rate within the first 24 h of treatment. Arterial oxygen tension (PaO2), PaO2/FIO2 (fractional inspired oxygen) ratio, and arterial oxygen saturation significantly improved after 1 h of treatment (43+/-10 vs 88+/-37 mmHg; 87+/-22 vs 175+/-64; 81+/-9 vs 95+/-4%, respectively) and continued to improve in the following 24 h (p < 0.01). Five patients died in the ICU following complications independent of the respiratory failure, while 11 were discharged from the ICU in stable condition after a mean stay of 4.3+/-2.4 days and were discharged in good condition from the hospital. CONCLUSIONS: NIV by nasal mask proved to be feasible and appropriate for the treatment of respiratory failure in hematologic patients who were at high risk of intubation-related complications.     

Tracheostomy: acute and long-term mortality and morbidity in very low birth weight premature infants

Thirty-six very low birth weight premature infants (VLBW-PT) born at 24 to 32 weeks gestation and with birth weights 635 to 1,360 g who had tracheostomies performed for acquired subglottic stenosis or for prolonged mechanical ventilation were followed in relation to acute and long-term mortality and morbidity. Mortality due to the tracheostomy occurred in 4 patients (11%); mortality from all other causes was 25%. Death after hospital discharge was associated with the nonuse of prescribed cardiorespiratory monitors. Complications < 1 week postsurgery occurred in 31% of infants and complications > or = 1 week postsurgery occurred in 64% of infants. Fifty percent of infants required tracheostomy for > 2 years and/or extensive reconstructive surgery of the airway. Parents should be counselled that VLBW-PT infants with a tracheostomy may require extended medical and home care. An effective home care program requires parental training in tracheostomy care, the use of ancillary equipment, and infant cardiopulmonary resuscitation.     

Tracheostomy in the young pediatric burn patient

OBJECTIVE: To evaluate the incidence of complications in comparison with the benefits of tracheostomy in young pediatric burn patients (newborn to 3 years old). DESIGN: Retrospective survey. SETTING: Tertiary care burn center. PATIENTS: A total of 1549 consecutive pediatric burn patients, of whom 180 were intubated. INTERVENTIONS: Tracheostomy was performed in 76 children. MAIN OUTCOME MEASURES: Duration of mechanical ventilation, mortality, respiratory complications, airway complications, and condition of the airway at discharge from the hospital. RESULTS: Seventy-six patients required tracheostomy. Their mean burn size was 34% total body surface area and mean length of stay in the hospital was 56 days. There were no perioperative complications. Eight patients (10%) could not be decannulated because of airway obstruction. Five of these outgrew their obstruction, 2 required surgery, and 1 continues to be evaluated for laryngeal reconstruction. CONCLUSION: Pediatric tracheostomy can be performed safely with no perioperative complications and acceptable chronic morbidity.     

Tracheostomy can make a difference in recurrent respiratory failure secondary to olivopontocerebellar atrophy

This article describes the case of a 55-year-old white male with olivopontocerebellar atrophy who was admitted to the ICU at Ohio Valley Medical Center because of recurrent respiratory failure. He had to remain in the ICU for 21 days on a ventilator even though he was hemodynamically stable with no evidence of pneumonia. A tracheostomy was then performed and within five days he was able to be weaned from the ventilator and transferred to a long-term care facility. This case suggests that early tracheostomy may play an important role in acute and long-term management in patients with olivopontocerebellar atrophy.     

Acute hormone responses to heavy resistance lower and upper extremity exercise in young versus old men

In the final stage of amyotrophic lateral sclerosis (ALS) the majority of patients develop chronic respiratory failure due to respiratory muscle weakness. The interaction between the patient with ALS and the physician should be characterized by continuous communication, especially with respect to the prospect of ventilatory failure and for support. The patient and his family must be informed thoroughly about the natural history and the prognosis of ALS, depending on the individual disease process. Already in the early stage of the disease coping strategies should be discussed so that imminent respiratory emergencies can be handled. If ALS patients are not informed about the acute respiratory insufficiency they run the risk of having to be intubated and mechanically ventilated over a long term. If dyspnea and hypersecretion dominate the final stage of ALS, the therapeutic strategy consists of the administration of morphine, insufflation of oxygen and bronchoscopic suction. Mechanical ventilation should only be initiated in the exceptional case. However, if dyspnea occurs in the early stage of the disease, when there is no bulbar paralysis and peripheral muscle function is intact, then noninvasive mechanical ventilation via mask may improve the quality of life substantially. Nevertheless, invasive mechanical ventilation via a tracheostomy should be avoided.     

Home treatment for chronic respiratory failure in children: a prospective study

Home treatment for children with chronic respiratory failure (CRF) is increasing. However, the causes of CRF in children and the details of their home treatment are not well-known. The aim of this study was to describe the causes of CRF in the paediatric population and the treatments that the patients received at home. We surveyed all children (aged < or = 18 yrs) entering the Association Nationale pour le Traitement à Domicile de l'Insuffisance Respiratoire chronique (ANTADIR) for home treatment of CRF between March 1992 and March 1993. Two hundred and eighty seven children (178 boys, 62%) started home treatment for CRF during the year. One hundred and eleven patients had obstructive respiratory disease: cystic fibrosis (CF) (n = 24); bronchopulmonary dysplasia (BPD) (n = 79); other obstructive respiratory disease (n = 8). One hundred and seventy six patients had restrictive lung disease: neuromuscular disease (n = 87); kyphoscoliosis (n = 21); pulmonary fibrosis (n = 6); cardiac disease (n = 14); stomatological disease (n = 10); other restrictive respiratory disease (n = 9); and 29 miscellaneous causes. One hundred and thirteen patients received oxygen therapy, with a mean daily use of 17.7 h (20 h.day-1 for BPD patients and 12.3 h.day-1 for CF patients). Oxygen was delivered by a concentrator in 88% of cases. One hundred and fifty eight children received mechanical ventilation (MV). Five children received nasal continuous positive airway pressure ventilation for sleep apnoea, four had pneumatic belt ventilation, and 12 had a tracheostomy without MV. Treatment was stopped in 21 children, because of death in nine and improvement in the other 12. Home treatment for children with CRF is well developed in France via the ANTADIR network. Causes of CRF in children are heterogeneous, with a relatively good prognosis.     

Current status of long term ventilation of children in the United Kingdom: questionnaire survey

OBJECTIVES: To identify the number and current location of children, aged 0 to 16 years, requiring long term ventilation in the United Kingdom, and to establish their underlying diagnoses and ventilatory needs. DESIGN: Postal questionnaires sent to consultant respiratory paediatricians and all lead clinicians of intensive care and special care baby units in the United Kingdom. SUBJECTS: All children in the United Kingdom who, when medically stable, continue to need a mechanical aid for breathing. RESULTS: 141 children requiring long term ventilation were identified from the initial questionnaire. Detailed information was then obtained on 136 children from 30 units. Thirty three children (24%) required continuous positive pressure ventilation by tracheostomy over 24 hours, and 103 received ventilation when asleep by a non-invasive mask (n=62; 46%), tracheostomy (n=32; 24%), or negative pressure ventilation (n=9; 7%). Underlying conditions included neuromuscular disease (n=62; 46%), congenital central hypoventilation syndrome (n=18; 13%), spinal injury (n=16; 12%), craniofacial syndromes (n=9; 7%), bronchopulmonary dysplasia (n=6; 4%), and others (n=25; 18%). 93 children were cared for at home. 43 children remained in hospital because of home circumstances, inadequate funding, or lack of provision of home carers. 96 children were of school age and 43 were attending mainstream school. CONCLUSIONS: A significant increase in the number of children requiring long term ventilation in the United Kingdom has occurred over the past decade. Contributing factors include improved technology, developments in paediatric non-invasive ventilatory support, and a change in attitude towards home care. Successful discharge home and return to school is occurring even for severely disabled patients. Funding and home carers are common obstacles to discharge.     

Long-term outcome when major complications follow coronary artery bypass graft surgery. Recovery after complicated coronary artery bypass graft surgery

OBJECTIVE: To determine whether information available 1 week after surgery correlates with long-term function in patients who suffer major complications after coronary artery bypass graft (CABG) surgery. DESIGN: An inception cohort study. SETTING: A 526-bed community teaching hospital. PATIENTS: All 67 patients who required at least 7 days of CT-ICU care following 2,751 consecutive CABG operations. MAIN OUTCOMES: Hospital survival, long-term survival, and functional ability at long-term follow-up. RESULTS: Forty-three patients survived hospitalization (64%), while 24 died 37 +/- 45 days (range, 7 to 190 days) after surgery. When 42 patients were surveyed 22 +/- 9 months after surgery, 21 of the survivors enjoyed excellent, independent function, 7 were moderately impaired but living at home, 6 were institutionalized with severe limitations, and 8 had died. Patients with very severe cardiac or neurologic dysfunction 1 week after surgery had an extremely poor outcome. When mechanical ventilation was required for causes other than primary failure of the respiratory system, long-term function and hospital survival were poor. Twelve of 14 patients with pulmonary complications survived hospitalization, and all 12 were alive at long-term follow-up. CONCLUSION: More than half of patients requiring 7 days or more of ICU treatment after CABG surgery survive, and many enjoy excellent long-term function. However, those with very severe cardiac or neurologic dysfunction 1 week after surgery have little chance for independent recovery.     

Design, testing, and results of an outcomes-managed approach to patients requiring prolonged mechanical ventilation

BACKGROUND: Outcomes management that uses critical pathways may decrease costs while improving outcomes for patients who require prolonged mechanical ventilation. OBJECTIVE: To study the efficacy of an outcomes-managed approach to weaning patients from prolonged (more than 3 days) mechanical ventilation. METHODS: A method of multidisciplinary care delivery was designed that included an outcomes manager, a care pathway for patients receiving mechanical ventilation, and weaning protocols. Data collection consisted of three parts: a retrospective review of 124 patients who required prolonged ventilation during a 1-year period before implementation of the care model, a 6-month prospective study in which 91 patients were alternately assigned by month to an outcomes-managed approach or a non-outcomes-managed approach, and a 6-month prospective study of 90 patients in which an outcomes-managed approach without alternate-month assignment was used. RESULTS: Outcomes management had no significant effect on total duration of mechanical ventilation or length of stay in the hospital, days of mechanical ventilation without tracheostomy, days of mechanical ventilation with tracheostomy, or outcome (weaned, withdrawal from mechanical ventilation, death, or transfer without weaning). However, duration of mechanical ventilation was 1.3 days shorter, length of stay in the hospital was 2.1 days shorter, and the cost per case was $ 3341 less for patients in the outcomes-managed group than for patients in the non-outcomes-managed group. CONCLUSION: Outcomes-managed care did not have a significant effect on duration of ventilation, length of stay in the hospital, or outcome in patients receiving long-term mechanical ventilation.     

Comparison of oxygen cost of breathing with pressure-support ventilation and biphasic intermittent positive airway pressure ventilation

OBJECTIVE: To assess the oxygen cost of breathing with either pressure-support ventilation (PSV) or biphasic intermittent positive airway pressure ventilation (BIPAP). DESIGN: Prospective, randomized, crossover study. SETTING: Medical intensive care unit of a university hospital. PATIENTS: Twenty clinically stable and spontaneously breathing patients after long-term mechanical ventilation. INTERVENTIONS: Patients were randomized to start on either PSV or BIPAP, and measurements were performed after an adaptation period of 30 mins. Immediately after, the ventilatory mode was changed and after another 30-min adaptation period, the same measurements were performed. MEASUREMENTS AND MAIN RESULTS: Indirect calorimetry was performed during each ventilatory mode for a period of 30 mins. Oxygen consumption, energy expenditure, CO2 production, and respiratory quotient did not differ significantly between the two ventilatory modes, regardless of the patients' randomization. There were no statistically significant differences with regard to respiratory rate, minute volume, and blood gas analysis. All patients tolerated both ventilatory modes without any signs of discomfort. CONCLUSIONS: Pressure support ventilation and BIPAP are both used for weaning patients gradually from the ventilator. BIPAP may be advantageous in patients not breathing sufficiently with PSV, since no patient effort is necessary with use of this ventilatory mode.     

Predicting the duration of mechanical ventilation. The importance of disease and patient characteristics

STUDY OBJECTIVE: To analyze the determinants of an individual patient's duration of mechanical ventilation and assess interhospital variations for average durations of ventilation. DESIGN: Prospective, multicenter, inception, cohort study. SETTING: Forty-two ICUs at 40 US hospitals. PATIENTS: A total of 5,915 patients undergoing mechanical ventilation on ICU day 1 selected from the acute physiology and chronic health evaluation (APACHE) III database of 17,440 admissions. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Utilizing APACHE III data collected on the 5,915 patients, multivariate regression analysis was performed on selected patients and disease characteristics to determine which variables were significantly associated with the duration of mechanical ventilation. An equation predicting duration of ventilation was then developed using the significant predictor variables and its accuracy was evaluated. Variables significantly associated with duration of ventilation included primary reason for ICU admission, day 1 acute physiology score (APS) of APACHE III, age, prior patient location and hospital length of stay, activity limits due to respiratory disease, serum albumin, respiratory rate, and PaO2/FIo2 measurements. Using an equation derived from these variables, predicted durations of ventilation were then calculated and compared with actual observed durations for each of the 42 ICUs. Average duration of ventilation for the 42 ICUs ranged from 2.6 to 7.9 days, but 60% of this variation was accounted for by differences in patient characteristics. CONCLUSIONS: For patients admitted to the ICU and ventilated on day 1, total duration of ventilation is primarily determined by admitting diagnosis and degree of physiologic derangement as measured by APS. An equation developed using multivariate regression techniques can accurately predict average duration of ventilation for groups of ICU patients, and we believe this equation will be useful for comparing ventilator practices between ICUs, controlling for patient differences in clinical trials of new therapies or weaning techniques, and as a quality improvement mechanism.     

Pulse oximetry in severe carbon monoxide poisoning

STUDY OBJECTIVES: To evaluate the accuracy and quantitate the error of pulse oximetry measurements of arterial oxygenation in patients with severe carbon monoxide (CO) poisoning. DESIGN: Retrospective review of patient clinical records. SETTING: Regional referral center for hyperbaric oxygen therapy. PATIENTS: Thirty patients referred for treatment of acute severe CO poisoning who demonstrated carboxyhemoglobin (COHb) levels >25%, with simultaneous determinations of arterial hemoglobin oxygen saturation by pulse oximetry (SpO2) and arterial blood gas (ABG) techniques. MEASUREMENTS AND RESULTS: COHb levels and measurements of arterial oxygenation from pulse oximetry, ABG analysis, and laboratory CO oximetry were compared. SpO2 did not correlate with COHb levels. SpO2 consistently overestimated the fractional arterial oxygen saturation. The difference between arterial hemoglobin oxygen saturation (SaO2) calculated from ABG analysis and SpO2 increased with increasing COHb level. CONCLUSIONS: Presently available pulse oximeters overestimate arterial oxygenation in patients with severe CO poisoning. An elevated COHb level falsely elevates the SaO2 measurements from pulse oximetry, usually by an amount less than the COHb level, confirming a prior observation in an animal model. Accurate assessment of arterial oxygen content in patients with CO poisoning can currently be performed only by analysis of arterial blood with a laboratory CO-oximetry.     

Impact on the immune system of undetectable plasma HIV-1 RNA for more than 2 years

The role of ICU support in BMT patients is controversial. In an era of constrained resources, the use of prognostic factors predicting outcome may be helpful in identifying patients who are most likely (or unlikely) to benefit from this intervention. We attempted to define the survival of patients admitted to ICU following autologous or allogeneic BMT and to identify those factors important in determining patient outcome. A retrospective study of all adult BMT recipients admitted to intensive care over a 6 year study period was performed to determine overall and prognostic indicators of poor outcome. Pre-treatment, pre-ICU admission and ICU admission data were analyzed to identify factors predicting long-term survival. 116 patients were admitted to ICU on 135 separate occasions with the primary reasons for admission being respiratory failure (66%), sepsis associated with hypotension (10%), and cardiorespiratory failure (8%). No pre-ICU characteristics were predictive of survival. Univariate analysis identified the number of support measures required, the need for ventilation or hemodynamic support, the APACHE II score, the year of ICU admission and the serum bilirubin as significant predictors of post-discharge survival. On multivariate analysis the year of ICU admission, the need for hemodynamic support and the serum bilirubin remained significant. The APACHE II score significantly underestimated survival in the 46% of patients with scores less than 35, and could only be used to predict 100% mortality when it exceeded 45. Twenty-three percent of all BMT patients admitted to the ICU and 17% of ventilated patients survived to hospital discharge. Of the 27 patients surviving to leave hospital, 16 remain alive with a median follow-up of 4.2 years and a mean Karnofsky performance status of 90. Although mortality in BMT recipients admitted to ICU is high our results indicate that intensive care support can be lifesaving and that the outcome in patients requiring ventilation and ICU support may not be as poor as has been previously reported. No single variable was identified which could be used to predict futility but patients requiring both hemodynamic support and mechanical ventilation, and those with an APACHE II score greater than 45 have a very poor prognosis and are unlikely to benefit from lengthy ICU support.     

Risk factors of psychosis: identifying vulnerable populations premorbidly

Most patients with primarily ventilation impairment can use noninvasive alternatives to tracheostomy for long-term ventilatory support and airway secretion management. The most important and versatile method of noninvasive ventilatory support is mouthpiece intermittent positive pressure ventilation. Mouthpiece intermittent positive pressure ventilation also can be used via a Lipseal for nocturnal support. The intermittent abdominal pressure ventilator is an option for daytime aid, and nasal intermittent positive pressure ventilation is usually preferred for nocturnal support. Manually assisted coughing and mechanical insufflation-exsufflation can be critical for airway secretion elimination.     

Long-term effects of selective decontamination on antimicrobial resistance

OBJECTIVE: To determine whether selective decontamination of the digestive tract exerts any long-term effects on antimicrobial resistance patterns. DESIGN: A surveillance and interventional study comparing the antimicrobial sensitivity patterns of clinically important bacterial isolates the year before a 2-yr, double-blind, randomized, controlled study of selective decontamination of the digestive tract, and for the year thereafter when no use of the regimen was made. SETTING: A ten-bed respiratory intensive care unit (ICU) in a 1,200-bed teaching hospital. PATIENTS: All 1,528 patients admitted to the ICU over the 4-yr study period were included. There were 406 patients admitted in the year before the study of decontamination of the digestive tract (65% medical, 23% surgical, and 12% trauma), of whom 76% required mechanical ventilation. There were 719 patients admitted during the 2-yr study of selective decontamination (55% medical, 28% surgical, and 17% trauma), of whom 79.6% required mechanical ventilation. There were 403 patients admitted in the subsequent year (61% medical, 25% surgical, and 14% trauma), of whom 76.9% required mechanical ventilation. INTERVENTIONS: We performed daily clinical monitoring to detect nosocomial infection, with microbiological investigation when clinically indicated, as well as twice-weekly routine microbiological surveillance sampling. Antimicrobial susceptibility testing using standard laboratory methods was also performed. Selective decontamination of the digestive tract included parenteral cefotaxime and oral and enteral polymyxin E, amphotericin B, and tobramycin. MEASUREMENTS AND MAIN RESULTS: The occurrence rate of nosocomial infection was 20.6%, 16.6%, and 25.3%, respectively, in the three study periods. In the year after selective decontamination, there was an increase in the occurrence rate of infection (p = .005), with an-associated increase in infections caused by the Enterobacteriaceae, while a reduction in the level of resistance to the third-generation cephalosporins were found (p = .07). There was a progressive increase in the occurrence rate of infections caused by Acinetobacter species (p = .05). Only 11 infections over the 4 yrs were caused by Enterococcus species. Staphylococcal infections were uncommon (5.7% of admissions), and the level of methicillin resistance did not change. No increase in aminoglycoside resistance occurred. CONCLUSION: No long-term effects on antimicrobial resistance or the spectrum of nosocomial pathogens could be attributed to the use of selective decontamination of the digestive tract over a 2-yr period in a respiratory ICU admitting all categories of patients.     

Neuromuscular ventilatory insufficiency: effect of home mechanical ventilator use v oxygen therapy on pneumonia and hospitalization rates

The purpose of this study was to determine rates of pneumonia and hospitalization for patients receiving oxygen therapy, patients having indwelling tracheostomy tubes, and those using tracheostomy or noninvasive methods of home mechanical ventilation. Six hundred eighty-four users of assisted ventilation for 13,751 patient-years or 19.8 years per patient were surveyed by mail and twice by telephone over a span of four years. Pneumonia and hospitalization rates were significantly higher for ventilator users with chronic obstructive pulmonary disease or with neuromuscular ventilatory insufficiency and gastrostomy tubes than for ventilator users with neuromuscular ventilatory insufficiency without gastrostomy tubes. Of the latter group, more than 90% of the pneumonias and hospitalizations were triggered by otherwise benign intercurrent upper respiratory tract infections. Oxygen therapy was associated with a significantly (P < 0.001) higher rate of pneumonias and hospitalizations than that seen for untreated patients after initial episodes of respiratory distress or during the use of either tracheostomy intermittent positive pressure ventilation or noninvasive ventilatory assistance methods. The lowest pneumonia and hospitalization rates (P < 0.001) were by full-time, noninvasive intermittent positive pressure ventilation users. We conclude that oxygen therapy is not an effective substitute for assisted ventilation for patients with primarily ventilatory insufficiency. Noninvasive ventilatory aids can be used effectively for up to full-time ventilatory support for patients with neuromuscular conditions whose bulbar muscle function is adequate to avert the need for gastrostomy tube placement.     

Successful treatment of severe dysrhythmias in infants with respiratory syncytial virus infections: two cases and a literature review

OBJECTIVES: To describe severe myocardial manifestations in two infants with respiratory syncytial virus infection and to review published literature reporting cardiac involvement in patients with respiratory syncytial virus disease. DESIGN: Case report and literature review. SETTING: Tertiary care pediatric intensive care unit (ICU). PATIENTS: Two infants admitted to the pediatric ICU for dysrhythmias and severe myocardial dysfunction and infected with respiratory syncytial virus. INTERVENTIONS: Conventional cardiovascular, antidysrhythmic, and respiratory support, as well as extracorporeal membrane oxygenation and high-frequency oscillatory ventilation. MEASUREMENTS AND MAIN RESULTS: Both patients had respiratory syncytial virus infections and clinical evidence of severe myocarditis, with dysrhythmias, cardiomegaly, and cardiogenic shock. Both infants survived their hospitalizations. To our knowledge, these two patients are the first reported cases of myocarditis in infants with respiratory syncytial virus infection. CONCLUSIONS: Severe myocardial dysfunction and dysrhythmias may accompany respiratory syncytial virus infection in some infants and may be reversible with aggressive supportive therapy.     

Sequential use of noninvasive pressure support ventilation for acute exacerbations of COPD

OBJECTIVES: To compare the efficacy of noninvasive pressure support ventilation (NIPSV) in acute decompensation in chronic obstructive pulmonary disease (COPD) by means of a bi-level positive airway pressure support system (BiPAP) in a sequential mode with medical therapy alone; to assess the short-term physiologic effects of the device on gas exchange; and to compare patients successfully ventilated with NIPSV with those in whom NIPSV failed. DESIGN: A prospective case series with historically matched control study. SETTING: A general intensive care unit (ICU) of a university hospital. PATIENTS: We evaluated the efficacy of administration of NIPSV in 42 COPD patients and compared this with standard treatment in 42 matched historical control COPD patients. INTERVENTIONS: NIPSV was performed in a sequential mode, i.e., BiPAP in the spontaneous mode was used for at least 30 min every 3 h. Between periods of ventilation, patients could be systematically returned to BiPAP when the arterial oxygen saturation was < 0.85 or when the respiratory rate was > 30 breaths/min. MEASUREMENTS AND RESULTS: Success rate, mortality, duration of ventilatory assistance, and length of ICU stay were recorded. Eleven of the 42 patients (26%) in the NIPSV group needed tracheal intubation compared with 30 of the 42 control patients (71%). The 31 patients in whom NIPSV was successful were ventilated for a mean of 6 +/- 3 days. In-hospital mortality was not significantly different in the treated versus the control group, but the duration of ventilatory assistance (7 +/- 4 days vs 15 +/- 10 days, p < 0.01) and the length of ICU stay (9 +/- 4 days vs 21 +/- 12, p < 0.01) were both shortened by NIPSV. BiPAP was effective in correcting gas exchange abnormalities. The pH values, measured after 45 min of BiPAP with optimal settings, in the success (7.38 +/- 0.04) and failure (7.28 +/- 0.04) patients were significantly different (p < 0.05). CONCLUSIONS: NIPSV, performed with a sequential mode, may be used in the management of patients with acute exacerbations of COPD.