No abstract available.
Laparoscopy ; Respiratory Mechanics

No abstract available.
Respiration, Artificial* ; Respiratory Mechanics*

No abstract available.
Humans ; Prone Position* ; Respiratory Mechanics*

No abstract available.
Humans ; Prone Position* ; Respiratory Mechanics*

PURPOSETo make the capacity model of SMART new-type multi-functional ventilator achieve the capability that the flow can be stable and adjusted accurately.

METHODSTo analysis the problems in the course of development with fluid mechanics principle, find the deficiencies of original design and improve it.

RESULTSThe inspiratory phase waveform of IPPV. SIMV,etc, breathing pattern presented square wave, achieved the goal of adjustable flow.

CONCLUSIONSUsing the fluid mechanics principle guiding the design of ventilator gas circuit can get twice the result with half the effort.

To learn reading respiratory waveform and ring is a key step to good use of respirator, which will help clinicians to analyze the status of the use of respirator and real time changes in patient's lung mechanics from the changes of respiratory wave and ring, for making use of respirator reasonably, scientifically and objectively to provide advanced methods. This article only explains the physical basis of respiratory wave and ring.
Respiration ; Respiration, Artificial ; methods ; Respiratory Mechanics

The main stream of intraabdominal surgery has changed from laparotomy to laparoscopy, but anesthetic care for laparoscopic surgery is challenging for clinicians, because pneumoperitoneum might aggravate respiratory mechanics and arterial oxygenation. The authors reviewed the literature regarding ventilation strategies that reduce deleterious pulmonary physiologic changes during pneumoperitoneum for laparoscopic surgery under general anesthesia and make appropriate recommendations.
Anesthesia, General ; Laparoscopy* ; Laparotomy ; Oxygen ; Pneumoperitoneum ; Respiratory Mechanics ; Rivers ; Ventilation*

BACKGROUND: The creation of pneumoperitoneum and Trendelenburg positioning during laparoscopic surgery are associated with respiratory changes. We aimed to compare respiratory mechanics while using intravenous propofol and remifentanil vs. sevoflurane during laparoscopic colectomy. METHODS: Sixty patients undergoing laparoscopic colectomy were randomly allocated to one of the two groups: group PR (propofol-remifentanil group; n = 30), and group S (sevoflurane group; n = 30). Peak inspiratory pressure (PIP), dynamic lung compliance (Cdyn), and respiratory resistance (Rrs) values at five different time points: 5 minutes after induction of anesthesia (supine position, T1), 3 minutes after pneumoperitoneum (lithotomy position, T2), 3 minutes after pneumoperitoneum while in the lithotomy-Trendelenburg position (T3), 30 minutes after pneumoperitoneum (T4), and 3 minutes after deflation of pneumoperitoneum (T5). RESULTS: In both groups, there were significant increases in PIP and Rrs while Cdyn decreased at times T2, T3, and T4 compared to T1 (P < 0.001). The Rrs of group PR for T2, T3, and T4 were significantly higher than those measured in group S for the corresponding time points (P < 0.05). CONCLUSIONS: Respiratory mechanics can be adversely affected during laparoscopic colectomy. Respiratory resistance was significantly higher during propofol-remifentanil anesthesia than sevoflurane anesthesia.
Anesthesia* ; Colectomy* ; Humans ; Laparoscopy ; Lung Compliance ; Pneumoperitoneum ; Propofol ; Respiratory Mechanics*

The forced oscillation technique (FOT) is a noninvasive method for respiratory mechanics measurement. For the FOT, external signals (e.g. forced oscillations around 4-40 Hz) are used to drive the respiratory system, and the mechanical characteristic of the respiratory system can be determined with the linear system identification theory. Thus, respiratory mechanical properties and components at different frequency and location of the airway can be explored by specifically developed forcing waveforms. In this paper, the theory, methodology and clinical application of the FOT is reviewed, including measure ment theory, driving signals, models of respiratory system, algorithm for impedance identification, and requirement on apparatus. Finally, the future development of this technique is also discussed.
Algorithms ; Electric Impedance ; Oscillometry ; Physical Therapy Modalities ; Respiratory Mechanics

BACKGROUND: The advantage of a laparoscopic cholecystectomy has led to a trend toward performing it in the elderly. It is well recognised that this can cause changes in respiratory mechanics. However, few studies have measured the effects of abdominal insufflation with CO2 in the elderly. This study was done to evaluate changes in respiratory compliance and peak airway pressure during a laparoscopic cholecystectomy. METHODS: Thirty patients undergoing a laparoscopic cholecystectomy were divided into two groups; aged 65 years or more (elderly group) and under 60 years (control group). A pneumoperitoneum up to an intraabdominal pressure of 12 mmHg was created with CO2 insufflation. Respiratory and peak airway pressure were measured with a continuous spirometry. Measurements were obtained pre-insufflation, just after CO2 insufflation, at 15, 30, 45 and 60 minutes and after abdominal deflation. RESULTS: In both groups, respiratory compliance decreased significantly (P < 0.05) and equally by about 40% after CO2 insufflation. The decrement continued during the pneumoperitoneum, the changes were not significant between the groups. Each group showed an equal improvement immediately after abdominal deflation. No differences between the peak airway pressure during a laparoscopic cholecystectomy was seen in either group. CONCLUSIONS: We have demonstrated that during a laparoscopic cholecystectomy in the elderly the respiratory compliance decreased and peak airway pressure significantly increased as in the control group.
Aged* ; Cholecystectomy, Laparoscopic* ; Compliance* ; Humans ; Insufflation ; Pneumoperitoneum ; Respiratory Mechanics ; Spirometry