PURPOSE: This study was conducted to compare effects of open and closed suctioning methods on lung dynamics (dynamic compliance, tidal volume, and airway resistance) and hypoxemia (oxygen saturation and heart rate) in mechanically ventilated patients. METHODS: This study was a cross-over repeated design. Participants were 21 adult patients being treated with endotracheal intubation using a pressure-controlled ventilator below Fraction of Inspired Oxygen (FiO2) 60% and PEEP 8 cmH2O. Data were collected at baseline and 1, 2, 3, 4, 5, and 10 minutes after suctioning. Data were analyzed using two-factor ANOVA with repeated measures on time and suctioning type. RESULTS: Effects of the interaction between suction type and time were significant for oxygen saturation and heart rate but not significant for dynamic compliance, tidal volume, or airway resistance. Prior to performance of suctioning, tidal volume and oxygen saturation were significantly lower, but airway pressure and heart rate were significantly higher using the closed suctioning method as compared with the open suctioning method. CONCLUSION: For patients on ventilator therapy below FiO2 60% and PEEP 8cmH2O, open suctioning performed after delivery of 100% FiO2 using a mechanical ventilator may not have as much negative impact on lung dynamics and hypoxemia as closed suctioning.
APACHE ; Adult ; Aged ; Aged, 80 and over ; Anoxia/*physiopathology/therapy ; Female ; Heart Rate/physiology ; Humans ; Intubation, Intratracheal ; Lung/*physiopathology ; Male ; Middle Aged ; Oxygen Consumption/physiology ; Respiration, Artificial/*instrumentation ; Suction

The risk analysis of clinical claims of mechanical ventilator can provide the useful information to the application of the availability and safety of mechanical ventilators. This paper classifies the clinical claims of two types of mechanical ventilations, and tries to find the distribution characteristics of the failure rate of the clinical claims by using the hazard analysis method. All of the distribution characteristics are related to the factors as ventilator design, environment human factors, etc. The method of risk analysis, combining with the classification of clinical claims, is useful for the clinical application and engineering services of mechanical ventilation.
Data Interpretation, Statistical ; Equipment Failure Analysis ; statistics & numerical data ; Humans ; Respiration, Artificial ; adverse effects ; instrumentation ; standards ; Risk Assessment ; Ventilators, Mechanical ; adverse effects ; standards

To improve success rates of noninvasive ventilation, a new type nasal-oral mask was designed with high comfort level, high security and less leakage, which overcame the weak points of intolerance and poor treatment effect of the conventional nasal-oral mask.
Equipment Design ; Masks ; Respiration, Artificial ; instrumentation

An impeller plays a significant role in the non-invasive ventilator. This paper shows a model of impeller for noninvasive ventilator established with the software Solidworks. The model was studied for feasibility based on ANSYS. Then stress and strain of the impeller were discussed under the external loads. The results of the analysis provided verification for the reliable design of impellers.
Equipment Design ; Humans ; Respiration, Artificial ; instrumentation ; Software ; Stress, Mechanical ; Ventilators, Mechanical

OBJECTIVE: To compare the diagnostic value of sterility sputum aspirating tube with bronchoalveolar lavage in mechanically ventilated patients with lower respiratory infection. METHODS: Sixty-four mechanically ventilated patients with lower respiratory infection were selected to collect respiratory passage secretion to analyze the etiology and to evaluate the diagnostic value by using sterility tube aspirate sputum and bronchoalveolar lavage. RESULTS: The positive rate of sterility tube aspirate sputum and bronchoalveolar lavage was 71.88% and 78.13%, respectively, with no statistical difference between the 2 groups (P>0.05). The consistency rate was 81.25% for the 2 methods. CONCLUSION Sterility sputum aspirating tube can not only acquire accurate pathogen, provide evidence to select sensitive antibiotics in clinical practice, but also is a simple practice, safe and economical method for patients with lower respiratory tract infection and mechanical ventilation.
Adult ; Aged ; Aged, 80 and over ; Bronchoalveolar Lavage Fluid ; microbiology ; Bronchoscopes ; Female ; Humans ; Male ; Middle Aged ; Pneumonia ; diagnosis ; etiology ; microbiology ; Respiration, Artificial ; adverse effects ; Sputum ; microbiology ; Suction ; instrumentation ; methods ; Young Adult

A 1D point-prevalence study was performed to describe the characteristics of conventional mechanical ventilation in intensive care units (ICUs). In addition, a survey was conducted to determine the characteristics of ICUs. A prospective, multicenter study was performed in ICUs at 24 university hospitals. The study population consisted of 223 patients who were receiving mechanical ventilation or had been weaned off mechanical ventilation within the past 24 hr. Common indications for the initiation of mechanical ventilation included acute respiratory failure (66%), acute exacerbation of chronic respiratory failure (15%) (including tuberculosis-destroyed lung [5%]), coma (13%), and neuromuscular disorders (6%). Mechanical ventilation was delivered via an endotracheal tube in 68% of the patients, tracheostomy in 28% and facial mask with noninvasive ventilation (NIV) in 4%. NIV was used in 2 centers. In patients who had undergone tracheostomy, the procedure had been performed 16.9+/-8.1 days after intubation. Intensivists treated 29% of the patients. A need for additional educational programs regarding clinical practice in the ICU was expressed by 62% of the staff and 42% of the nurses. Tuberculosis-destroyed lung is a common indication for mechanical ventilation in acute exacerbation of chronic respiratory failure, and noninvasive ventilation was used in a limited number of ICUs.
APACHE ; Acute Disease ; Aged ; Data Collection ; Education, Professional, Retraining ; Female ; Hospitals, University ; Humans ; *Intensive Care Units ; Intubation, Intratracheal ; Male ; Middle Aged ; Prospective Studies ; *Respiration, Artificial/instrumentation ; Respiratory Insufficiency/therapy ; Tracheostomy

The design principles of a noninvasive ventilator's turbine are studied and discussed in this paper. The design is completed from its several aspects and in combination of related theories, using SolidWorks tools. Abundant experimental results prove that this design's technical specifications meet all the requirements.
Equipment Design ; Respiration, Artificial ; instrumentation ; methods ; Ventilators, Mechanical

The CobraPLA(TM) (CPLA) is a relatively new supraglottic airway device that has not been sufficiently investigated. Here, we performed a prospective observational study to evaluate the efficacy of the CPLA during controlled ventilation. In 50 anesthetized and paralyzed patients undergoing elective surgery a CPLA was inserted and inflated to an intracuff pressure of 60 cm H2O. The success rate of insertion upon the first attempt was 82% (41/50), with a mean insertion time of 16.3 +/- 4.5 seconds. The adequacy of ventilation was assessed by observing the end tidal CO2 waveform, movement of the chest wall, peak airway pressure (13.5 cm H2O), and leak fraction (4%). We documented the airway sealing pressure (22.5 cm H2O) and noted that the the site of gas leaks at that pressure were either at the neck (52%), the abdomen (46%), or both (2%). In 44 (88%) patients, the vocal cords were visible in the fiberoptic view through the CPLA. There was no gastric insufflation during the anesthesia. Respiratory and hemodynamic parameters remained stable during CPLA insertion. Postoperative blood staining of CPLA was minimal, occurring in 22% (11/50) of patients. Mild and moderate throat soreness was reported in 44% (22/50) and 4% (2/50) of patients, respectively. Lastly, mild dysphonia was observed in 6% (3/50) of patients and mild dysphagia in 10% (5/50) of patients. Our results indicated that the CPLA is both easy to place and allows adequate ventilation during controlled ventilation.
Respiration, Artificial/adverse effects/*instrumentation ; Middle Aged ; Male ; Intubation/adverse effects/*instrumentation ; Hypopharynx ; Humans ; Female ; Anesthesia/*methods ; Adult

BACKGROUNDPulmonary surfactant dysfunction may contribute to the development of ventilator induced lung injury (VILI). Tracheal gas insufflation (TGI) is a technique in which fresh gas is introduced into the trachea and augment ventilation by reducing the dead space of ventilatory system, reducing ventilatory pressures and tidal volume (V(T)) while maintaining constant partial arterial CO2 pressure (PaCO(2)). We hypothesised that TGI limited peak inspiratory pressure (PIP) and V(T) and would minimize conventional mechanical ventilation (CMV) induced pulmonary surfactant dysfunction and thereby attenuate VILI in rabbits with acute lung injury (ALI).

METHODSALI was induced by intratracheal administration of lipopolysaccharide in anaesthetized, ventilated healthy adult rabbits randomly assigned to continuous TGI at 0.5 L/min (TGI group) or CMV group (n = 8 for each group), and subsequently ventilated with limited PIP and V(T) to maintain PaCO(2) within 35 to 45 mmHg for 4 hours. Physiological dead space to V(T) ratio (V(D)/V(T)), dynamic respiratory compliance (Cdyn) and partial arterial O(2) pressure (PaO(2)) were monitored. After ventilation, lungs were analysed for total phospholipids (TPL), total proteins (TP), pulmonary surfactant small to large aggregates ratio (SA/LA) in bronchoalveolar lavage fluid (BALF) and for determination of alveolar volume density (V(V)), myeloperoxidase and interleukin (IL)-8.

RESULTSTGI resulted in significant (P < 0.05 or P < 0.01) decrease in PIP [(22.4 +/- 1.8) cmH2O vs (29.5 +/- 1.1) cmH2O], V(T) [(6.9 +/- 1.3) ml/kg vs (9.8 +/- 1.11) ml/kg], V(D)/V(T) [(32 +/- 5)% vs (46 +/- 2)%], TP [(109 +/- 22) mg/kg vs (187 +/- 25) mg/kg], SA/LA (2.5 +/- 0.4 vs 5.4 +/- 0.7), myeloperoxidase [(6.2 +/- 0.5) U/g tissue vs (12.3 +/- 0.8) U/g tissue] and IL-8 [(987 +/- 106) ng/g tissue vs (24 +/- 3) mN/m] of BALF, and significant (P < 0.05) increase in Cdyn [(0.47 +/- 0.02) ml.cmH2O(-1).kg(-1) vs (0.31 +/- 0.02) ml.cmH2O(-1).kg(-1)], PaO(2) [(175 +/- 24) mmHg vs (135 +/- 26) mmHg], TPL/TP (52 +/- 8 vs 33 +/- 11) and Vv (0.65 +/- 0.05 vs 0.44 +/- 0.07) as compared with CMV.

CONCLUSIONSIn this animal model of ALI, TGI decreased ventilatory requirements (PIP, V(T) and V(D)/V(T)), resulted in more favourable alveolar pulmonary surfactant composition and function and less severity of lung injury than CMV. TGI in combination with pressure limited ventilation may be a lung protective strategy for ALI.

Animals ; Insufflation ; Intubation, Intratracheal ; instrumentation ; Lung ; pathology ; Pressure ; Pulmonary Surfactants ; analysis ; Rabbits ; Respiration, Artificial ; methods ; Respiratory Distress Syndrome, Adult ; therapy ; Tidal Volume ; Trachea ; physiopathology

Based on the structure and principle of transducers for medical ventilators, this paper analyzes the causes of transducers' failures, and introduces some corresponding calibration methods. Besides, some suggestions about how to reduce different kind of transducer failures are put forward.
Calibration ; Equipment Failure ; Equipment Failure Analysis ; methods ; standards ; Equipment Safety ; methods ; Maintenance ; Respiration, Artificial ; instrumentation ; Transducers ; Ventilators, Mechanical