Analysis on the volume control of red blood cells in additive solution produced by Chongqing blood services / 中国输血杂志

【Objective】 To investigate the current situation concerning volume control of red blood cells in additive solution produced by blood service in Chongqing, and to lay a foundation for promoting the homogenization of preparation process of red blood cells in additive solution. 【Methods】 A questionnaire was designed to investigate the factors related to the preparation of red blood cells in additive solution. The questionnaire was sent by Chongqing Association of Blood Transfusion via E-mail to 18 blood services in the city, and the collected data was sorted, revised and analyzed by research team. 【Results】 A total of 18 blood services(including 1 blood center + 1 sub-center, 6 central blood stations and 11 central blood banks) returned the questionnaires. The results showed that there were differences among blood services across Chongqing, regarding the centrifugal parameters during preparation, the operation mode and monitoring situation of the capacity control during preparation, and the formulation of the capacity standard of red blood cells in additive solution etc. 【Conclusion】 The preparation process of red blood cells in additive solution, produced by Chongqing blood services, should be further standardized, and the capacity control method of this product in Chongqing should be gradually unified to achieve regional homogeneity and to ensure blood safety.

A analysis on the effect of PRVC mode of ventilator for mechanical ventilation efficiency / 中国医学装备

Objective:To analyze the advantages of the pressure-regulated volume control (PRVC) mode compared with the traditional continuous mandatory ventilation (CMV) mode about mechanical ventilation efficiency of ventilator.Methods: For the mechanical ventilation situations, the parameters of PRVC mode, V-CMV mode and P-CMV mode under same detecting conditions were tested by using gas analyzer, which based on the ventilation principle of PRVC mode. And then the differences between PRVC mode and CMV modes were analyzed. Results: PRVC mode can supply the almost same tidal volume, and provide lower pressure and higher compliance compare with the V–CMV mode under the same conditions. On the other hand, PRVC mode can supply more tidal volume and slightly higher compliance compare with the P–CMV mode under the same pressure.Conclusion: PRVC mode has combined with the advantages of CMV mode, and it can make sure the target tidal volume, at the same time, reduce the pressure of airway, and improve the compliance for circuit. It also can make the mechanical ventilation to got more efficiency and more safety.

Volume Control by Using the Body Composition Monitor in a Puerperal Patient on Hemodialysis

Accurate measurement of the volume status in hemodialysis patients is important as it can affect mortality. However, no studies have been conducted regarding volume management in cases where a sudden change of body fluid occurs, such as during puerperium in hemodialysis patients. This report presents a case in which the patient was monitored for her body composition and her volume status was controlled using a body composition monitor (BCM) during the puerperal period. This case suggests that using a BCM for volume management may help maintain hemodynamic stability in patients with a rapidly changing volume status for a short term period, such as during puerperium.

Comparative study on effects of volume-controlled ventilation and pressure-limited ventilation for neonatal respiratory distress syndrome / 소아과

PURPOSE: In contrast with traditional time-cycled, pressure-limited ventilation, during volume-controlled ventilation, a nearly constant tidal volume is delivered with reducing volutrauma and the episodes of hypoxemia. The aim of this study was to compare the efficacy of pressure-regulated, volume controlled ventilation (PRVC) to Synchronized intermittent mandatory ventilation (SIMV) in VLBW infants with respiratory distress syndrome (RDS). METHODS: 34 very low birth weight (VLBW) infants who had RDS were randomized to receive either PRVC or SIMV with surfactant administration : PRVC group (n=14) and SIMV group (n=20). We compared peak inspiratory pressure (PIP), duration of mechanical ventilation, and complications associated with ventilation, respectively with medical records. RESULTS: There were no statistical differences in clinical characteristics between the groups. After surfactant administration, PIP was significantly lower during PRVC ventilation for 48hrs and accumulatevive value of decreased PIP was higher during PRVC ventilation for 24hrs (P <0.05). Duration of ventilation and incidence of complications was no significant difference. CONCLUSION: PRVC is the mode in which the smallest level of PIP required to deliver the preset tidal volume in VLBW infants with RDS, adaptively responding to compliance change in lung after surfactant replacement.

Comparison of volume-control and pressure-control ventilation during one-lung ventilation / 대한마취과학회지

BACKGROUND: We hypothesized that pressure control ventilation allows a more even distribution in the lung and better maintenance of the mean airway pressure than is achieved with volume control ventilation. We try to compare the effect of pressure control ventilation (PC) with that of volume control ventilation without an end-inspiratory pause (VC) during one-lung ventilation (OLV) in an anesthetized, paralyzed patient for performing thoracopic bullectomy of the lung. METHODS: We ventilated 20 patients with VC and PC after the insertion of a thoracoscope in continual order for, at least for 15 minutes, for each, VC and PC procedure. At the end of VC and PC, the respiratory mechanics, gasometrics, and hemodynamic parameters were measured and collected. RESULTS: We found no significant differences between VC and PC except for the peak inspiratory airway pressure (PIP), the mean airway pressure and the arterial oxygen partial pressure (PaO2). The PIP was significantly decreased from 27.0 +/- 6.0 cmH2O (VC) to 21.8 +/- 5.4 cmH2O (PC). The mean airway pressure was significantly increased from 8.6 +/- 1.6 cmH2O (VC) to 9.4 +/- 2.0 cmH2O (PC), and the PaO2 was significantly increased from 252.9 +/- 97.3 mmHg (VC) to 285.2 +/- 103.8 mmHg (PC). CONCLUSIONS: If PC allows mechanical ventilation with the same tidal volume and respiratory rate as VC during OLV, then PC significantly increases the PaO2 but this is not clinically significant, and the PC significantly decreases the PIP, which induces barotrauma or volutrauma when the PIP is excessively high.

Control method for biosafety cabinet / 医疗卫生装备

Biosafety cabinets(BSC)is the primary containment barrier.It is very important to choose suitable control method for the protection ability of biosafety cabinet.This paper briefly introduces the key points and several control methods as well as the different characteristics of BSC control.

Changes of Vital Signs, Expired Volume and Maximal Pressure by Mode of Ventilation during a Nuss Operation in Patients with Pectus Excavatum / 대한마취과학회지

BACKGROUND: This study was undertaken in order to investigate any cardiopulmonary changes caused by the surgical procedure during a Nuss operation in patients with pectus excavatum. METHODS: Thirty patients undergoing the Nuss operation were divided into two groups. The patients were randomly assigned to either Group-V (n = 15) which volume controlled ventilation was applied, or to Group-P (n = 15) where pressure controlled ventilation was applied. Mechanical ventilation provided a tidal volume to be set at approximately 10 ml/kg and a frequency set to keep ETCO2 in range, between 32 mmHg and 38 mmHg. During the surgical procedure, we recorded expired volume (VE) and inspired maximal pressure (Pmax) changes according to the ventilator mode, and then also recorded changes in vital signs. RESULTS: Heart rate and blood pressure had no significant changes in either groups. In Group-V, during rotation of the metal bar, there was a significant decrease in expired volume (P< 0.001), changes of inspired maximal pressure gradually increased with the operation (P< 0.001). In Group-P, rotation of the metal bar caused a significant decrease in expired volume (P< 0.001). CONCLUSIONS: During the Nuss operation, there should be careful observation of changes in the vital signs, expired volume and maximal pressure during insertion and rotation of the metal bar.

The Usefulness of Pressure-regulated Volume Control(PRVC) Mode in Mechanically Ventilated Patients with Unstable Respiratory Mechanics / 결핵

BACKGROUND: Since the late 1960s, mechanical ventilation has been accomplished primarily using volume controlled ventilation(VCV). While VCV allows a set tidal volume to be guaranteed, VCV could bring about excessive airway pressures that may be lead to barotrauma in the patients with acute lung injury. With the increment of knowledge related to ventilator-induced lung injury, pressure controlled ventilation(PCV) has been frequenfly applied to these patients. But, PCV has a disadvantage of variable tidal volume delivery as pulinonary impedance changes. Since the concept of combining the positive attributes of VCV and PCV(dual control ventilation, DCV) was described firstly in 1992, a few DCV modes were introduced. Pressure-regulated volume control(PRVC) mode, a kind of DCV, is pressure-limited, time-cycled ventilation that uses tidal volume as a feedback control for continuously adjusting the pressure limit. However, no clinical studies were published on the efficacy of PRVC until now. This investigation studied the efficacy of PRVC in the patients with unstable respiratory mechanics. METHODS: The subjects were 8 mechanically ventilated patients(M: F= 6 : 2, 56+/-26 years) who showed unstable respiratory mechanics, which was defined by the coefficients of variation of peak inspiratory pressure for 15 minutes greater than 10% under VCV, or the coefficients of variation of tidal volume greater than 10% under PCV. The study was consisited of 3 modes application with VCV, PCV and PRVC for 15 minutes by random order. To obtain same tidal volume, inspiratory pressure setting was adjusted in PCV. Respiratory parameters were measured by pulmonary monitor(CP-100 pulmonary monitor, Bicore, Irvine, CA, USA). RESULTS: 1) Mean tidal volumes(VT) in each mode were not different(VCV, 431+/-102ml ; PCV, 417+/-99ml; PRVC, 414+/-97ml) 2) The coefficient of variation(CV) of VT were 5.2+/-3.9% in VCV, 15.2+/-7.5% in PCV and 19.3+/-10.0% in PRVC. The CV of VT in PCV and PRVC were significantly greater than that in VCV(p<0.01). 3) Mean peak inspiratory pressure(PIP) in VCV(31.0+/-6.9cm HD) was higher than PIP in PCV(26.0+/-6.5cm H20) or PRVC(27.0+/-6.4cm HD)(p<0.05). 4) The CV of PIP were 13.9+/-3.7% in VCV, 4.9+/-2.6% in PVC and 12.2+/-7.0% in PRVC. The CV of PIP in VCV and PRVC were greater than that in PCV(p<0.01). CONCLUSIONS: Because of wide fluctuations of VT and PIP, PRVC mode did not seem to have advantages compared to VCV or PCV in the patients with unstable respiratory mechanics.