Objective To evaluate the efficiency and associated factors of noninvasive positive pressure ventilation( NPPV) in the treatment of acute lung injury( ALI) and acute respiratory distress syndrome( ARDS) .Methods Twenty-eight patients who fulfilled the criteria for ALI/ARDS were enrolled in the study. The patients were randomized to receive either noninvasive positive pressure ventilation( NPPV group) or oxygen therapy through a Venturi mask( control group) . All patients were closely observed and evaluated during observation period in order to determine if the patients meet the preset intubation criteria and the associated risk factors. Results The success rate in avoiding intubation in the NPPV group was 66. 7%( 10/15) , which was significantly lower than that in the control group ( 33. 3% vs. 86. 4% , P = 0. 009) . However, there was no significant difference in the mortality between two groups( 7. 7% vs.27. 3% , P =0. 300) . The incidence rates of pulmonary bacteria infection and multiple organ damage were significantly lower in the NPPV success subgroup as compared with the NPPV failure group( 2 /10 vs. 4/5, P =0. 01;1 /10 vs. 3/5, P = 0. 03) . Correlation analysis showed that failure of NPPV was significantly associated with pulmonary bacterial infection and multiple organ damage( r=0. 58, P lt;0. 05; r =0. 53, P lt;0. 05) . Logistic stepwise regression analysis showed that pulmonary bacterial infection was an independent risk factor associated with failure of NPPV( r2 =0. 33, P =0. 024) . In the success subgroup, respiratory rate significantly decreased( 29 ±4 breaths /min vs. 33 ±5 breaths /min, P lt; 0. 05) and PaO2 /FiO2 significantly increased ( 191 ±63 mmHg vs. 147 ±55 mmHg, P lt;0. 05) at the time of 24 hours after NPPV treatment as compared with baseline. There were no significant change after NPPV treatment in heart rate, APACHEⅡ score, pH and PaCO2 ( all P gt;0. 05) . On the other hand in the failure subgroup, after 24 hours NPPV treatment, respiratory rate significantly increased( 40 ±3 breaths /min vs. 33 ±3 breaths /min, P lt;0. 05) and PaO2 /FiO2 showed a tendency to decline( 98 ±16 mmHg vs. 123 ±34 mmHg, P gt; 0. 05) . Conclusions In selected patients, NPPV is an effective and safe intervention for ALI/ARDS with improvement of pulmonary oxygenation and decrease of intubation rate. The results of current study support the use of NPPV in ALI/ARDS as the firstline choice of early intervention with mechanical ventilation.
Objective To observe the survival rate of reversed-flow free flap after anastomosing one venous reverse flow and to explore the change of intravenous pressure and mechanism of venous reverse flow. Methods Thefree vascularized posterior tibial flap with reversed flow was successfully established in NewZealand white rabbits.Fifteen rabbits were randomly allocated into 3 groups of 30 flaps. In group A,two vena comitans were anastomosed.In groups B and C,only onevenae comitans was anastomosed. In groups A and B,intravenous pressure was measured immediately and 30,60 and 120 minutes after anastomosing the vascular pedicle.Flap survival rate of group B was measured after two weeks. In group C, radiography of one venae comitans was observed.The diameters of posterior tibial vessels was measured on all the rabbits before anastomosing the vascular pedicle. Results The diameters of posterior tibial artery was 8.0±0.3mm and of vena comitans was 11.0±0.5 mm。The intravenous pressure of group B increased rapidly and reached its top value after about 30 minutes (P＜0.05).It then decreased and approached normal level after about 60 minutes (Pgt;0.05).The intravenous pressure was not significantly different between groups A and B in each time interval (Pgt;0.05).Two flapsresulted in avulsion,infection and necrosis.The remaining 8 flaps survived completely.Most of the radiopaque in group C flew back to the proximal tibia one hourlater. Conclusion Venous retrograde return is abundant in reverseflow free flap of anatomosing one vena comitans.The main way of venous reflux in reverseflow free flap can be through “direct incompetent valve route”.
Objective To study the effect of noninvasive positive pressure ventilation (NPPV) in chronic obstructive pulmonary disease (COPD) patients with hypercapnic coma secondary to respiratory failure.Methods COPD patients with or without coma secondary to respiratory failure were both treated by bi-level positive airway pressure (BiPAP) ventilation on base of routine therapy.There were 32 cases in coma group and 42 cases in non-coma group.Such parameters as arterial blood gas (ABG)，Glasgow coma scale (GCS)，time of NPPV therapy，achievement ratio，and adverse effects were investigated.Results 30 patients in the coma group were improved after NPPV treatment (26 cases recovered consciousness treated by BiPAP in 2 hours，3 cases recovered between 3~8 hours，1 case recovered after 24 hours).The parameters of ABG，the tidal volume and the minute ventilation volume were improved after BiPAP.The time of effective therapy was (9±4) days in the coma group and (7±3) days in the non-coma group with no significant difference (Pgt;0.05).The achievement ratio was similar in two groups (93.75% vs 97.62%，Pgt;0.05).But the incidence of gastrointestinal tympanites reached to a higher level in the coma group (80.5%) than the non-coma group (10.6%).Conclusion COPD patients with hypercapnic coma secondary to respiratory failure isn’t the absolute contraindication of NPPV treatment.
ObjectiveTo explore the reason of failure in noninvasive positive pressure ventilation (NPPV) for treatment of postoperative hypoxemia, in order to better guide use of NPPV after cardiac surgery. MethodsWe retrospectively analyzed the clinical data of 64 patients after heart surgery with undergoing NPPV treatment due to hypoxemia in our hospital between January 2012 and December 2013 year.There were 49 males and 15 females at age of 28 to 87 years. There were 17 patients with NPPV failure. The related factors for failure of NPPV were analyzed. ResultsFactors associated with failure of NPPV included smoking history, preoperative pulmonary function abnormalities, blood transfusion amount > 1 000 ml, simplified acute physiology score Ⅱ(SAPS Ⅱ) before NPPV > 35 points, oxygenation index (PaO2/FiO2) < 100 mm Hg before NPPV, PaO2/FiO2 < 150 mm Hg after NPPV treatment for 1 h, mechanical ventilation time > 72 h at the first time, and pneumonia (P < 0.05). The SAPS Ⅱ > 35 points before NPPV and pneumonia were the independent risk factors for NPPV treatment failure for postoperative hypoxemia. ConclusionPostoperative NPPV for heart disease should be according to the cause of low oxygen and severity. For patients with SAPS less than 35 points before NPPV or patients with pneumonia, NPPV should not be used. In the process of NPPV, if clinical effect is not satisfied, it should be converted to invasive ventilation immediately.
Objective To investigate the characteristics of blood pressure and coronary artery impairment in patients with essential hypertension (EH) combining coronary heart disease (CHD). Methods A total of 358 patients with EH combining CHD and other 144 patients with CHD were measured with ambulatory blood pressure monitoring (ABPM), and the parameters of ambulatory blood pressure were analyzed. All the patients underwent coronary angiography. The severity of coronary artery stenosis was evaluated in accordance with the number of impaired arteries. Results Compared to the patients with simplex CHD, those with EH combining CHD had much heavier artery stenosis and more diffuse lesions, with significant differences (χ2=6.03, P=0.019). The 24h systolic blood pressure (SBP), day SBP, night SBP, 24h pulse pressure (PP), day PP and night PP were higher in the patients with EH combining CHD compared to those of the patients with simplex CHD (The t values were 2.580, 2.045, 2.675, 2.037, 2.601, and 1.995, respectively, while the P values were 0.015, 0.037, 0.009, 0.041, 0.017, and 0.047, respectively). Conclusion Compared to the patients with simplex CHD, the patients with EH combining CHD suffer from much severe coronary artery impairment, so a good controlling of blood pressure is advisable to improve the coronary artery impairment for the patients with EH combining CHD.
Objective To compare the effect of two types of intermittent pressure on formation of pressure ulcer in rabbit hind l imbs and to investigate the mechanism of gradually changed intermittent pressure produced by waves bed in the prevention of pressure ulcer. Methods Gracil is (3 cm2) in both hind l imbs of 12 adult Japanese white rabbits were randomlyloaded with gradually changed intermittent pressure (50-160 mm Hg, 1 mm Hg=0.133 kPa) and sustained pressure (100 mmHg) serving as the experimental group and the control group, respectively. The experiment was terminated after 4 cycles, and a single cycle included 2 hours of compression and 30 minutes of compression-release. Blood velocity of hind l imbs and blood perfusion of wound were detected by bidirectional doppler blood flow detector and laser doppler perfusion imaging detection system before compression and at every 10 minutes in compression-release period of each cycle (0, 10, 20 and 30 minutes). After the termination, gross observation of the wound was conducted, pathomorphological changes of tissues from compressed area were observed by HE staining, and contents of NO, malondialdehyde (MDA), and superoxide dismutase (SOD) in muscle tissue were measured using colorimetry method. Results No significant difference was evident between two groups in terms of blood flow velocity before compression (P gt; 0.05); the blood flow velocity of two groups decreased significantly at 0 minute in every compressionrelease period of each cycle, and no significant differences were noted between two groups (P gt; 0.05); the blood flow velocity of theexperimental group was higher than that of the control group at 10, 20 and 30 minutes (P lt; 0.05). No significant difference was noted between two groups in terms of wound blood perfusion before compression (P gt; 0.05); the wound blood perfusion of two groups decreased significantly at 0 minute in every compression-release period of each cycle, and no significant differences were noted between two groups (P gt; 0.05); the difference between two groups was not significant at 10 minutes in the first cycle (P gt; 0.05), and the experimental group was higher than the control group at 20 and 30 minutes in the first cycle (P lt; 0.05). In the following 3 cycles, the recovery of perfusion in the experimental group was faster than that of the control group (P lt; 0.05). Gross observation showed the experimental group had less effusion than the control group. The experimental group had intact cutaneous appendage, less inflammatory cell infiltration, and no obvious ulcer formation, whereas the control group had obvious skin ulcer, depletion of cutaneous appendage, and more inflammatory cells infiltration. Significant differences were noted between two groups in terms of NO, MDA, and SOD content (P lt; 0.05). Conclusion Gradually changed intermittent pressure can maintain the blood perfusion of tissue, reduce ischemia-reperfusion injury and cell apoptosis, and prevent the formation of pressure ulcer.
Objective To investigate the effects of intermittent negative pressure on the mRNA expression of osteoprotegerin (OPG) and osteoprotegerin l igand (OPGL) in human BMSCs cultured in vitro. Methods BMSCs were isolated from adult marrow donated by 2 hip osteoarthritis patients with prosthetic replacement in January 2008 and cultured in vitro. The third passage cells were divided into experimental group and control group. The experimental group was induced by negative pressure intermittently for 2 weeks (pressure: 50 kPa, 30 minutes each time, twice per day) and the control groupwas routinely cultured. After 2 weeks of culture, cell morphology was observed by inverted phase contrast microscope, and the mRNA expressions of OPG and OPGL in BMSCs were analyzed by real-time PCR. Results The cell prol iferation speed of the experimental group was slower than that of the control group. The cell morph changed from shuttle to megagon with some prominences in experimental group and the cell morph kept shuttle in the control. The mRNA expression of OPG in experimental group increased significantly (P lt; 0.01) and the mRNA expression of OPGL in experimental group decreased significantly compared with control group (P lt; 0.01) 2 weeks later. Conclusion Intermittent negative pressure is capable of promoting the expression of OPG, while inhibiting the expression of OPGL in human BMSCs.
摘要:目的:研究老年患者动脉弹性功能与围术期血压变化的关系。方法:随机选择68例ASA分级Ⅰ－Ⅱ级行全麻手术的老年患者,根据检查所得动脉弹性的结果分为四组,分别是A组(C1、C2均正常),B组(C1异常,C2正常),C组(C1正常,C2异常),D组(C1、C2均异常)。测量其术前血压及全麻诱导8分钟后的血压水平。结果:〓动脉弹性功能不良的患者其术前MAP较高,且全麻诱导以后血压波动的比例较大。结论:高血压病的老年患者动脉弹性功能普遍降低;动脉弹性下降的老年病人全麻诱导后血压波动较大。Abstract: Objective:To investigate the relationship between the function of arterial elasticity and BP changes during perioperation in senile patients.Methods: 68 senile patients ASA class Ⅰor Ⅱ undergoing elective surgery under general anesthestia, were divided into four groups by evaluation of arterial elasticity (C1 was for large arterial elastic index and C2 for small. C1 and C2 were normal in group A, only C2 normal in group B, only C1 normal in group C, neither was normal in group D). Arterial blood pressure (BP) before operation and 8 min after induction were monitored and recorded. Results: Patients with dysfunction of arterial elasticity presented higher MAP during preoperation and significant BP changes after induction. Conclusion: Hypertension plays a key role in arterial elasticity.Arterial Blood Pressure of the senile patients with decreased arterial elasticity changes significantly after general anesthesia induction.
Blood pressure variability (BPV) is a novel predictor related to blood pressure level, and a large number of studies based on the hypertension cohort have shown that BPV is an independent predictor of target organ damages and cardiovascular adverse outcomes. Due to the significant hemodynamic changes, BPV in patients with chronic kidney disease (CKD) and hemodialysis is higher than the simple hypertension cohort, suggesting that BPV may be of great significance to patients with chronic kidney disease and hemodialysis. In recent years, studies based on CKD and hemodialysis cohort have published in succession whose results revealed that BPV of this cohort is of great prognostic significance for predicting target organ damages and cardiovascular disease risks. This article aims to provide an overview on these research, so as to survey and predict the clinical significance of BPV in CKD and hemodialytic patients.
Based on force sensing resistor(FSR) sensor, we designed insoles for pressure measurement, which were stable and reliable with a simple structure, and easy to wear and to do outdoor experiments with. So the insoles could be used for gait detection system. The hardware includes plantar pressure sensor array, signal conditioning unit and main circuit unit. The software has the function of data acquisition, signal processing, feature extraction and classification function. We collected 27 groups of gait data of a healthy person based on this system to analyze the data and study pressure distribution under various gait features, i.e. walking on the flat ground, uphill, downhill, up the stairs, and down the stairs. These five gait patterns for pattern recognition and classification by K-nearest neighbors (KNN) recognition algorithm reached up to 90% accuracy. This preliminarily verified the usefulness of the system.