Simulation of the human biological lung is a crucial method for medical professionals to learn and practice the use of new pulmonary interventional diagnostic and therapeutic devices. The study on ventilation effects of the simulation under positive pressure ventilation mode provide valuable guidance for clinical ventilation treatment. This study focused on establishing an electrical simulation ventilation model, which aims to address the complexities in parameter configuration and slow display of air pressure and airflow waveforms in simulating the human biological lung under positive pressure ventilation mode. A simulated ventilation experiment was conducted under pressure-regulated volume control (PRVC) positive pressure ventilation mode, and the resulting ventilation waveform was compared with that of normal adults. The experimental findings indicated that the average error of the main reference index moisture value was 9.8% under PRVC positive pressure ventilation mode, effectively simulating the ventilatory effect observed in normal adults. So the established electrical simulation ventilation model is feasible, and provides a foundation for further research on the simulation of human biological lung positive pressure ventilation experimental platform.
ObjectiveTo investigate the operation and effect of pressure ulcers group (PUG) on the procedure of clinical management of pressure ulcers. MethodsThe in-hospital patients with high-risk pressure ulcers and patients with pressure ulcers from outside of the hospital (n=145) before the founding of PUG in 2011 were regarded as group A, and patients in this group were treated by traditional therapies. After PUG was founded in our hospital in January 2012, 192 patients with high-risk pressure ulcers and from outside of the hospital in 2012 were considered as group B. In addition, group C contained 380 patients treated in 2013. Group B and C were both treated by PUG that developed a management system of pressure ulcers and took active measures to control and prevent pressure ulcers. PUG trained 30 clinical nurse supervisors, who were recommended from relevant clinical departments. The incidence of inevitable pressure ulcer of hospitalized patients, the cure rate of patients with pressure ulcers from outside of the hospital, pressure ulcer knowledge level of clinical nurse supervisors were comparatively analyzed between group A and B, and between group A and C, respectively. ResultsAfter the establishment of PUG, the incidence of inevitable pressure ulcer of hospitalized patients in group A, B, and C was 76.20%, 17.02%, and 14.61%, respectively. The cure rate of patients from outside of the hospital was 54.84%, 86.84%, and 87.97%, respectively. Differences between group A and B, and between group A and C both were significant (P<0.01). The pressure ulcer knowledge level of all nurse supervisors improved significantly (P<0.001). ConclusionThe establishment of PUG makes the clinical pressure ulcer management more scientific and objective. Furthermore, it can effectively reduce the incidence of pressure ulcers, and also improve the quality of medical care and ensure the safety of patients.
ObjectiveTo explore the preventive role of maintaining constant pressure of the endotracheal catheter cuff on ventilator-associated pneumonia (VAP). MethodsFrom January to December 2015, 96 patients of type Ⅱ respiratory failure were selected as the trial group who underwent intubation and mechanical ventilation more than 48 hours in the Intensive Care Unit (ICU). We used pressure gauges to measure the endotracheal catheter cuff pressure regularly and maintained a constant pressure in addition to the application of artificial airway cluster management. We recorded the initial pressure value which was estimated by pinching with finger and set initial pressure to 30 cm H2O (1 cm H2O=0.098 kPa). We measured endotracheal catheter cuff pressure and recorded it during different intervals. We reviewed 88 patients with the same disease as the control group who only accepted artificial airway cluster management between January and December 2014. Mechanical ventilation time, VAP occurrence time, ICU admission time, the incidence of VAP were recorded and analyzed for both the two groups of patients. ResultsIn the trial group, the initial pressure of endotracheal catheter cuff which was estimated by pinching with finger showed that only 11.46% of pressure was between 25 and 30 cm H2O and 82.29% of the pressure was higher than 30 cm H2O. We collected endotracheal catheter cuff pressure values during different interval time by using pressure gauges to maintain a constant management. The ratio at the pressure between 25 and 30 cm H2O was respectively 41.32%, 43.75%, 64.20%, 76.54%, 91.13%, and 91.85%. ICU admission time, mechanical ventilation time in patients of the trial group decreased more, compared with the control group, and the differences were statistically significant (t=4.171, P<0.001; t=4.061, P<0.001). The VAP occurrence time in patients of the trial group was later than the control group (t=2.247, P<0.001). ConclusionThe endotracheal catheter cuff pressure estimated by pinching with finger has errors. We recommend using pressure gauges to detect pressure every four hours, which utilizes minimal time to maintain effective pressure. The method of artificial airway of cluster management combined with the pattern of maintaining constant endotracheal catheter cuff pressure can shorten ICU admission time, mechanical ventilation time and delay the occurrence of VAP.
Objective To systematically evaluate the effectiveness and safety of Resina Draconis for pressure ulcer. Methods Such databases as The Cochrane Library (Issue 4, 2013), PubMed, Elsevier SDOL, Web of Knowledge, CBM, CNKI, VIP and WanFang Data were searched from inception to May 2013 to collect randomized controlled trials (RCTs) about Resina Draconis for pressure ulcer. Two reviewers were assigned to independently screen the literature according to inclusion and exclusion criteria, extract data, and appraise the methodological quality. Then, meta-analysis was conducted using RevMan 5.2.4 software. Results A total of 14 RCTs were included, involving 610 patients. The results of meta-analysis showed that, Resina Draconis treatment were associated with a higher effective rate for pressure ulcer (RR=1.17, 95%CI 1.08 to 1.26, Plt;0.000 1). The results of descriptive analysis showed that, compared with the control group, Resina Draconis treatment shortened healing time. As for safety, adverse reactions had not been reported. Conclusion Resina Draconis can improve the effective rate for pressure ulcer and shorten the healing time, compared with other drug treatments. However, due to limited quality and quantity of the included studies, this conclusion needs to be proved by more high quality studies.
ObjectiveTo investigate the physiologic effects of different pressure assist (PA) on ventilatory status,oxygenation and work of breathing (WOB) when a new generation of proportional assist ventilation (PAV) is applied in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). MethodsA prospective,crossover randomized physiologic study was performed.80%PA,60%PA and 40%PA was sequentially randomized to be applied with the duration of 30 minutes,and pressure support ventilation (PSV) with the duration of 30 minutes was applied before each PA.Ventilatory status, oxygenation,dyspnea indexes in PSV and different PA were compared,and WOB of patients and ventilator were compared in different PA. ResultsTwenty-eight patients were recruited into the study.With the decrease of PA,peak inspiratory pressure (PIP),mean airway pressure (Pm),and tidal volume (VT) decreased gradually (P>0.05),respiratory rate (RR) increased gradually (P<0.05),while minute volume (MV),heart rate (HR),systolic blood pressure (SBP),mean arterial pressure (MAP),pH,arterial carbon dioxide tension (PaCO2),and arterial oxygen tension/inspired oxygen fraction (PaO2/FiO2) did not change significantly (P>0.05).Compared with PSV mode,PIP increased significantly in 80%PA (P<0.05),decreased significantly in 60%PA and 40%PA (P<0.05).Pm did not change significantly in 80%PA (P>0.05),decreased significantly in 60%PA and 40%PA (P<0.05).VT increased significantly in 80%PA (P<0.05),decreased significantly in 60%PA and 40%PA (P<0.05).RR did not change significantly in 80%PA (P>0.05),increased significantly in 60%PA and 40%PA (P<0.05).MV did not change significantly in 80%PA (P>0.05),decreased significantly in 60%PA and 40%PA (P<0.05).With the decrease of PA,Borg score and scale for accessory muscle use increased gradually (P<0.05).Compared with PSV mode,Borg score and scale for accessory muscle use did not change significantly in 80%PA (P>0.05),increased significantly in 60%PA and 40%PA (P<0.05).WOB of patients in 40%PA was significantly higher than that in 60%PA (P=0.000) and that in 80%PA (P=0.000),while which in 60%PA was significantly higher than that in 80%PA (P=0.000).On the contrary,WOB of ventilator in 40%PA was significantly lower than that in 60%PA (P=0.004) and that in 80%PA (P=0.000),while which in 60%PA was significantly lower than that in 80%PA (P=0.000). ConclusionThe new generation of PAV can safely and effectively provide respiratory support to patients with AECOPD.Respiratory pattern,levels of dyspnea and accessory muscle use in 80%PA are similar with those in PSV.With the decrease of PA,levels of spontaneous breathing and WOB increase and dyspnea worsens.PAV can promote spontaneous breathing and prevent respiratory muscle disuse atrophy even more, but easily lead to respiratory muscle fatigue with inappropriate use.
ObjectiveTo analyze the pressure change and distribution of the intervertebral disc of upper thoracic spine in vertical pressure and 5° flexion, extension, or lateral bending. MethodsTwelve thoracolumbar spinal specimens were harvested from mini pigs and were divided into 2 groups (n=6). T1, 2, T3, 4, T5, 6, and T7, 8 segments were included in one group, and T2, 3, T4, 5, T6, 7, and T8, 9 segments were included in the other group. The data from both groups represented the complete upper thoracic vertebra data. Biomechanical machine and pressure sensitive film were used to measure the pressure on the vertebral columns under loadings of 100, 150, and 200 N in vertical pressures and 5° flexion, extension, or lateral bending. The pressure change of each intervertebral disc under different loads and in different movement conditions was analyzed. ResultsIn flexion, the anterior annulus pressure of the upper thoracic vertebra increased (P < 0.05), whereas the posterior annulus pressure showed no significant change (P > 0.05) or an increasing trend (P < 0.05). In extension, the anterior annulus pressure of the upper thoracic vertebra decreased (P < 0.05), whereas the posterior annulus pressure decreased (P < 0.05) or had no obvious change (P > 0.05). In lateral bending, the pressure on the concave side of the annulus increased significantly (P < 0.05). ConclusionThe upper thoracic vertebra has unique biomechanical characteristics under different loadings; moreover, the posterior vertebral structure plays an important role in the movement of the upper thoracic vertebral segment and pressure distribution. In lateral bending of the upper thoracic vertebra, the concave side pressure will increase significantly, which suggests that asymmetrical force is an important cause of scoliosis progression. Gravity plays an important role in the progression of scoliosis.
ObjectiveTo evaluate the association of intraoperative ventilation modes with postoperative pulmonary complications (PPCs) in adult patients undergoing selective cardiac surgery under cardiopulmonary bypass (CPB).MethodsThe clinical data of 604 patients who underwent selective cardiac surgical procedures under CPB in the West China Hospital, Sichuan University from June to December 2020 were retrospectively analyzed. There were 293 males and 311 females with an average age of 52.0±13.0 years. The patients were divided into 3 groups according to the ventilation modes, including a pressure-controlled ventilation-volume guarantee (PCV-VG) group (n=201), a pressure-controlled ventilation (PCV) group (n=200) and a volume-controlled ventilation (VCV) group (n=203). The association between intraoperative ventilation modes and PPCs (defined as composite of pneumonia, respiratory failure, atelectasis, pleural effusion and pneumothorax within 7 days after surgery) was analyzed using modified poisson regression. ResultsThe PPCs were found in a total of 246 (40.7%) patients, including 86 (42.8%) in the PCV-VG group, 75 (37.5%) in the PCV group and 85 (41.9%) in the VCV group. In the multivariable analysis, there was no statistical difference in PPCs risk associated with the use of either PCV-VG mode (aRR=0.951, 95%CI 0.749-1.209, P=0.683) or PCV mode (aRR= 0.827, 95%CI 0.645-1.060, P=0.133) compared with VCV mode. ConclusionAmong adults receiving selective cardiac surgery, PPCs risk does not differ significantly by using different intraoperative ventilation modes.
Objective To evaluate the prel iminary cl inical outcomes of percutaneous endoscopic lumbar discectomy (PELD) for patient with discogenic chronic low back pain (CLBP) and fail ing to respond to conservative treatment. Methods From June 2007 to May 2008, 52 patients with CLBP and fail ing to respond to conservative treatment were treated, including 15 males and 37 females aged 29-46 years old (average 38.2 years old). Those patients were diagnosed ith discogenic pain by low pressure discography. Duration of CLBP was 6-110 months with an average of 32.1 months. MRI exam revealed 108 “black intervertebral discs” low in signal on T2 image, including 3 discs of L2,3, 17 of L3,4, 48 of L4,5 and 40 of L5-S1. Pressure-controlled discography showed positive response, fluoroscopy or intraoperative CT confirmed annulus fibrosus tears of posterior intervertebral disc in 79 discs. PELD was performed. Visual analogue scale (VAS) was evaluated before operation, 1 month after operation and at the final follow-up. The cl inical outcome was determined by modified Macnab criteria at the final follow-up. Results The average operation time of each disc was 30.7 minutes (range 21-36 minutes), and the mean length of postoperative hospital stay was 3.7 days (range 2-5 days). No compl ications such as infection and the injury of blood vessels and nerves occurred. Transient paralysis of nerve occurred in 5 cases on operation day, and those symptoms were disappeared at the final follow-up visit without special treatment. Fifty-two cases were followed up for 3-15 months (average 7.3 months). VAS score before operation, 1 month after operation and at the final follow-up was (7.34 ± 1.52), (3.62 ± 0.92) and (1.57 ± 0.48) points, respectively, indicating there were significant differences compared with preoperative score (P lt; 0.01). According to the modified Macnab criteria, 11 cases were graded as excellent, 23 as good, 13 as fair, 5 as bad, and the excellent and good rate was 65.38%. Conclusion Prel iminary study suggests that PELD is safe and effective in treating patient with discogenic CLBP and fail ing to respond to conservative treatment.
Objective To explore the correlations between nutritional markers and pressure injury (PI) in elderly patients with chronic obstructive pulmonary disease (COPD). Methods Retrospective analysis was conducted on elderly patients with COPD and PI who were admitted to the geriatric department of West China Hospital of Sichuan University or Dujiangyan People’s Hospital between January 2020 and December 2021. The blood biochemical indicators mainly including nutritional markers were collected, and their correlations with PI risk factor index Braden score and PI severity index PI stage were analyzed. Results A total of 293 patients with COPD and PI were included. Among the five Braden score groups, the differences in the levels of albumin and prealbumin were statistically significant (P<0.05), and the Braden score was positively correlated with albumin (rs=0.241, P<0.001), prealbumin (rs=0.179, P=0.002), and hemoglobin (rs=0.199, P=0.001). Among the six PI stage groups, the differences in the levels of albumin, globulin, red blood cell count, serum sodium, blood chloride and C-reactive protein were statistically significant (P<0.05), and the PI stage was negatively correlated with albumin (rs=?0.192, P=0.001), and positively correlated with serum sodium (rs=0.139, P<0.001), blood chloride (rs=0.184, P<0.001), and C-reactive protein (rs=0.177, P=0.020). Conclusion When PI risk assessment and severity assessment are performed on elderly COPD patients, it is necessary to pay more attention to nutritional markers and assess whether the patients are at risk of protein malnutrition, which will help to improve the accuracy of PI risk assessment and severity prediction, and effectively improve the efficacy of PI prevention and treatment.
ObjectiveTo evaluate the accuracy of the new dynamic approach in the measurement of respiratory mechanics with different pressure support (PS) level during pressure support ventilation (PSV) via oral-nasal mask.MethodsThe Respironics V60 ventilator was connected to a ASL5000 lung simulator, which simulate lung mechanics in patients with chronic obstructive pulmonary disease ［system compliance (Crs)=50 mL/cm H2O, airway resistance (Raw)=20 cm H2O/(L·s), inspiratory time (TI)=1.6 s, breathing rate=15 beats per minute］. PSV were applied with different levels of PS ［positive end-expiratory pressure=5 cm H2O, PS=5/10/15/20/25 cm H2O) and back-up rate=10 beats per minute］. Measurements were conducted at system leaks with 25 – 28 L/min. The performance characteristics and patient-ventilator asynchrony were assessed, including flow, airway pressure, time and workload. Crs and Raw were calculated by using new dynamic approach.ResultsTidal volume (VT) was increased with increasing PS level ［(281.45±4.26)mL at PS 5 cm H2O vs. (456.81±1.91)mL at PS 10 cm H2O vs. (747.45±3.22)mL at PS 20 cm H2O, P<0.01］. Severe asynchronous was occurred frequently when PS is at 25 cm H2O. Inspiration cycling criterion (CC) was up-regulated accompanied by increasing PS level ［(15.62±3.11)% at 5 cm H2O, vs. (24.50±0.77)% at 20 cm H2O, P<0.01］. Premature cycling was always existed during PSV when PS < 20 cm H2O, which could be eliminated as PS level increasing. Delay cycling was found when PS was at 20 cm H2O, and cycling delay time was (33.60±15.91)ms (P<0.01). The measurement of Crs was (46.19±1.57)mL/cm H2O with PS at 10 cm H2O, which was closer to the preset values of simulated lung. The underestimate of Crs was observed during high level PS support. The calculation of inspiratory and expiratory resistance was approximate to 20 cm H2O/(L·s) when PS level was exceeded 15 cm H2O.ConclusionsThe new dynamic approach can continuously assess the respiratory mechanics during non-invasive ventilation, which is no need to interrupt the patient's spontaneous breathing. Higher inspiratory flow during PSV is beneficial for Raw measurement, whereas the accuracy of Crs was influenced by the value of actual VT.