Outcome of domiciliary nasal intermittent positive pressure ventilation in restrictive and obstructive disorders.

BACKGROUND--Nasal intermittent positive pressure ventilation (NIPPV) is a new technique which has rapidly supplanted other non-invasive methods of ventilation over the last 5-10 years. Data on its effectiveness are limited. METHODS--The outcome of long term domiciliary NIPPV has been analysed in 180 patients with hypercapnic respiratory failure predominantly due to chest wall restriction, neuromuscular disorders, or chronic obstructive lung disease. One hundred and thirty eight patients were started on NIPPV electively, and 42 following an acute hypercapnic exacerbation. Outcome measures were survival (five year probability of continuing NIPPV), pulmonary function, and health status. A crossover study from negative pressure ventilation to NIPPV was carried out in a subgroup of patients. RESULTS--Five year acturial probability of continuing NIPPV for individuals with early onset scoliosis (n = 47), previous poliomyelitis (n = 30), following tuberculous lung disease (n = 20), general neuromuscular disorders (n = 29), and chronic obstructive pulmonary disease (n = 33) was 79% (95% CI 66 to 92), 100%, 94% (95% CI 83 to 100), 81% (95% CI 61 to 100), 43% (95% CI 6 to 80), respectively. Most of the patients with bronchiectasis died within two years. One year after starting NIPPV electively the mean (SD) PaO2 compared with the pretreatment value was +1.8 (1.9) kPa, mean PaCO2 -1.4 (1.3) kPa in patients with extrapulmonary restrictive disorders, and PaO2 +0.8 (1.0) kPa, PaCO2 -0.9 (0.8) kPa in patients with obstructive lung disease. Arterial blood gas tensions improved in patients transferred from negative pressure ventilation to NIPPV. Health status was ranked highest in patients with early onset scoliosis, previous poliomyelitis, and following tuberculous lung disease. In the group as a whole health perception was comparable to outpatients with other chronic disorders. CONCLUSIONS--The long term outcome of domiciliary NIPPV in patients with chronic respiratory failure due to scoliosis, previous poliomyelitis, and chest wall and pulmonary disease secondary to tuberculosis is encouraging. The results of NIPPV in patients with COPD and progressive neuromuscular disorders show benefit in some subgroups. The outcome in end stage bronchiectasis is poor.     

Nasal mask positive pressure ventilation in paediatric patients with type II respiratory failure

We report our experience with nasal mask ventilation in children and adolescents with type II respiratory failure admitted to the paediatric intensive care unit (PICU) over an 18-month period. Seven patients were treated with nasal mask ventilation during part of their PICU stay. All showed significant improvement in arterial pH, Pa_CO2, and Pa_O2/FiO₂ from presentation to discharge, although at discharge Pa_CO2 and Pa_O2/FiO₂ fell outside of the normal range. Complications occurred in four patients. When compared to 11 patients with type II respiratory failure not treated with nasal mask ventilation, the nasal mask ventilation group had a similar PICU length of stay and incidence of complications. We conclude that nasal mask ventilation may be useful in maintaining near normal alveolar ventilation in selected children with type II respiratory failure and that a prospective study of this technique is indicated.     

Mechanics of ventilation with positive end-expiratory pressure.

The effect of graded increments in positive end-expiratory pressure (PEEP) on arterial oxygen partial pressure (PaO2) and shunt fraction (Qs/QT), oxygen delivery, and respiratory mechanics and work required to ventilate 8 critically ill patients is reported. The work required to ventilate the patients increases markedly with the application and progressive increase in the level of PEEP. However, improvement in lung mechanics lowers the net work of ventilating the lungs. At 20 cm H2O PEEP, the mean value for the work of ventilation in this group of patients is twice the mean value without PEEP. The increase in work of ventilation with PEEP is critical in the use of PEEP when patients are breathing spontaneously with or without intermittent mandatory ventilation.     

Nasal intermittent positive pressure ventilation in the treatment of respiratory failure in obstructive sleep apnoea

Severe respiratory failure in a patient with obstructive sleep apnoea was treated successfully with nasal intermittent positive pressure ventilation.     

Non-invasive positive pressure ventilation for severe thoracic trauma

A 35-year-old man was admitted to the intensive care unit (ICU)following a road traffic accident. He had sustained severe traumato the left side of his chest, as well as other musculoskeletalinjuries. After a short initial period of ventilation of thelungs via a tracheal tube, he was managed using a combinationof continuous positive airway pressure and non-invasive positivepressure ventilation. He avoided ventilator-associated pneumonia,and spent a large part of his time on the ICU without any invasivemonitoring lines, another potential focus of infection. He wasdischarged from the ICU after 25 days without having sufferedany septic complications. The role of non-invasive positivepressure ventilation in severe thoracic trauma is discussed. Br J Anaesth 2000; 85: 788–90 ^* Corresponding author     

Nasal continuous positive airway pressure: An alternative method for respiratory assistance

Study Objective: To examine the efficacy of a nasal continuous positive airway pressure (CPAP) system for respiratory support in patients who have respiratory insufficiency but are able to maintain spontaneous breathing without hypercapnia, respiratory acidosis, or deteriorated mental status.

Design: Prospective study.

Setting: Medical and surgical patients admitted to the intensive care unit (ICU) at the Hillel Yaffe Medical Center.

Patients: Nineteen patients with acute respiratory insufficiency and intact mental status who were able to maintain spontaneous breathing without hypercapnia or respiratory acidosis. Additional entry criteria were as follows: arterial oxygen tension (PaO₂) < 65 mmHg on inspired oxygen tension (FIO₂) ≥0.45, PaO₂/FIO₂ <150, respiratory rate >35 breaths/minute, and inability to tolerate mask CPAP.

Interventions: Nasal CPAP (10 cmH₂O) was applied to patients through two nasopharyngeal airways with an internal diameter (ID) of 8 mm each, inserted in both nostrils. During CPAP application, the patients were requested to breathe through their nose with their mouth closed. Even if they breathed through their open mouth, however, CPAP was maintained despite an observed pressure decrease of 4 cmH₂O.

Measurements and Main Results: All patients showed a constant improvement in arterial blood gases, PaO₂/FIO₂, and respiratory signs during nasal CPAP of 10 cmH₂O. PaO₂ increased from 52 ± 5.3 mmHg to 131 ± 20 mmHg with CPAP administration (p < 0.05), while arterial carbon dioxide tension (PaC02) increased from 32 ± 2 mmHg to 36 ± 2 mmHg (p < 0.05) and respiratory rate decreased from 39 ± 2.3 breaths/minute to 31 ± 1.6 breaths/minute (p < 0.05).

Conclusions: Nasal CPAP (10 cmH₂O) is a reliable alternative to support arterial oxygenation in patients with respiratory failure who are alert and vigorous enough to avoid hypercapnia and respiratory acidosis while breathing spontaneously. In addition, since the patients are able to speak and thus are capable of expressing their feelings, the anxiety observed during respiratory support can be reduced.     

间歇正压通气和呼气末正压通气对犬眼内压的影响

目的 探讨间歇正压通气(IPPV)和呼气末正压通气(PEEP)对犬眼内压(10P)的影响.方法 实验犬8只,麻醉后分别监测基础条件下和各种机械通气条件下的IOP、CVP、MAP.结果 实施20 ml/kg和30 ml/kg两种不同潮气量的IPPV时IOP差异无统计学意义.实施10、15、20cm H20三种不同压力值的PEEP时IOP均显著升高(P<0.01).结论 IPPV对IOP影响不大,PEEP可使IOP显著升高.     

Protocol-based noninvasive positive pressure ventilation for acute respiratory failure

Purpose  

Noninvasive positive pressure ventilation (NPPV) has been suggested to be associated with adverse outcomes in emergency patients with acute respiratory failure (ARF), possibly because of a delay in tracheal intubation (TI). We hypothesized that protocol-based NPPV (pNPPV) might improve the outcomes, compared with individual physician-directed NPPV (iNPPV).     

Anaesthesia for awake craniotomy with non-invasive positive pressure ventilation

Airway management during awake craniotomy is a crucial partof the anaesthetic technique, but it remains the subject ofdebate. We report two cases of anaesthesia for awake craniotomyusing non-invasive positive pressure ventilation; biphasic positiveairway pressure or proportional assist ventilation was employed.Both ventilatory techniques provided adequate lung ventilation,smooth transition between anaesthesia and arousal, and patientcomfort. Br J Anaesth 2003; 90: 382–5     

Cardiovascular effects of ventilation with positive expiratory airway pressure.

The broad clinical application of positive and expiratory pressure (PEEP) in the treatment of a variety of respiratory disorders has led to the observation that positive airway pressure can result in cardiac dysfunction. Recent attempts to integrate and extend the results of past research have led to diverse explanations of the overall cardiopulmonary effects of PEEP. This review summarizes previous work in the field and attempts to explain the basis of the divergent conclusions of previous investigators. Data are presented from several experimental models, as well as studies in postoperative patients to formulate an overall analysis of the influence of airway pressure on the central circulation. It appears that the effects of PEEP are primarily mechanical and are mediated through a combination of right ventricular preload limitation and outflow obstruction. Both effects are additive in limiting left ventricular preload and can be ameliorated by volume loading in the absence of significant right ventricular or pulmonary vascular disease. Neural, humoral and ventricular interactive forces appear to be insignificant under most circumstances. The clinical implications of these advances in the current understanding of PEEP are reviewed.     

Effect of positive end expiratory pressure ventilation on intracranial pressure in man.

THsi study was designed to define the effect of positive end expiratory pressure (PEEP) ventilation on intracranial pressure (ICP). In 25 patients with severe head trauma with and without associated pulmonary injury the following parameters were simultaneously monitored under mechanical ventilation with and without PEEP:ICP, arterial blood pressure, central venous pressure, arterial blood gases, and cardiac rate. In addition, the volume-pressure response (VPR) was evaluted in each patient to assess cerebral elastance. The results indicate a significant increase in ICP with the application of PEEP only in the 12 patients who manifested increased cerebral elastance by VPR. Half of this latter group manifested impairment of cerebral perfusion pressure to levels less than 60 mm Hg. Return to baseline CIP levels was observed with termination of PEEP. No significantly consistent changes in other parameters were noted.