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1.
The criteria for an oxygen fail-safe device are designed toprevent a hypoxic gas mixture being administered to the patientshould the oxygen supply fail, be disconnected, or be turnedoff. A fail-safe device which fulfils these criteria is described.  相似文献   

2.
Weaning patients from mechanical ventilation in the intensive care unit can be difficult. In patients requiring prolonged ventilatory support it has been demonstrated that conventional weaning criteria are frequently incorrect. In this group measurement of respiratory work may be of benefit. Until recently, estimation of the work of breathing in patients receiving mechanical ventilation was logistically difficult. The availability of a computerized bedside monitoring device potentially allows easier estimation of the work of breathing at the bedside. The results of preliminary studies utilizing such monitoring are provocative: they highlight the phenomenon of nosocomial respiratory failure and challenge our clinical ability to determine patient workloads and timing of extubation. The potential benefits of work of breathing measurement, in particular the avoidance of respiratory muscle fatigue, earlier extubation, reduced duration of mechanical ventilation, reduction in ICU and hospital length of stay, and most importantly, a reduction in patient morbidity are yet to be demonstrated and concerns still exist about the monitor's accuracy.  相似文献   

3.
Difficulties were experienced in weaning a patient from a ventilatorby means of intermittent mandatory ventilation (IMV). The difficultywas overcome by installing an alternative IMV system (Hudson"disposable IMV valve") through which the patient drew her spontaneousbreaths. Laboratory measurements showed that the resistanceof the ventilator breathing system was much higher than thatof the alternative system, mainly as a result of the resistanceof the humidifier. It was calculated from measurements witha preset pattern of simulated breathing that the extra, external,work of breathing through the ventilator breathing system wasapproximately 1.5 times the normal internal mechanical workof breathing for a normal patient; with the alternative system,the extra work was only 0.5 times the normal. It is stressedthat the breathing systems of IMV ventilators should be judgedwith the same rigour as other systems through which the patientis required to breathespontaneously. It is recommended thatmanufacturers should pro vide the necessary information.  相似文献   

4.
Over the last 10 years, the Laryngeal Mask Airway (LMA) has gained widespread acceptance as a general purpose airway for routine anaesthesia. Published data from large studies and reports have confirmed the safety and efficacy of the device for spontaneous and controlled ventilation during routine use. The initial experience with the LMA should ideally be confined to short cases requiring the patient to remain spontaneously ventilating. With experience, it will be found that less anesthetic agent is required during anesthesia with the LMA and patient recovery should be improved as a result. Spontaneous breathing is the chosen mode of ventilation in approximately 60% of LMA uses in the UK. During spontaneous breathing a minimal inspiratory pressure support will help with higher endtidal carbon dioxide levels. The anaesthetist should be experienced with using the LMA in spontaneously ventilating patients before using it with positive pressure ventilation. Several large scale studies have failed to show any link between positive pressure ventilation and pulmonary aspiration or gastric insufflation. The main disadvantage of the LMA is that it does not protect against aspiration. From a practical point of view, most fasted patients with normal lung compliance may be mechanically ventilated through the LMA to airway pressures of approximately 20 cmH2O. The low pressure seal implies that tidal volumes should be approximately 6-8 ml*kg-1 and the inspiratory flow rates should be reduced to achieve adequate and safe ventilation.  相似文献   

5.
A 43-year-old ASA PS II male patient developed a pneumothorax while breathing pontaneously through a supraglottic airway device during a general anaesthetic. Unexplained hypoxaemia occurred after an episode of coughing. Clinical examination appeared to be normal apart from the persistent oxygen desaturation. A pneumothorax was diagnosed in the post anaesthesia care unit by chest X-ray. The pneumothorax responded to conventional management and the patient made an uneventful recovery. We recommend a high index of suspicion in any patient who coughs and later has unexplained hypoxaemia during general anaesthesia, even if a supraglottic airway device has been inserted.  相似文献   

6.
Assessment of the performance of modern ventilators that combine spontaneous breathing and mechanical ventilation is orientated not only towards the assessment of the inspiratory and expiratory resistance within the system, but also towards the functional criteria for the inspiratory and expiratory valves. This conclusion is particularly valid for CPAP procedures, as in this case patients must perform the entire work of breathing by themselves. As it has proved to be extremely problematic to carry out comparative testing of ventilators on patients in the intensive care unit, a breathing simulator has been developed, the use of which has enabled us to have a "patient" at our disposal who can tolerate the procedures for measuring the performance of ventilators with IMV and with CPAP without injury. The pressure-flow characteristics and the work of breathing can thus be measured under constant conditions and with various ventilation systems. Exact analysis of the pressure curve pattern under standardized conditions proved to be of value for assessing the suitability of CPAP in the case of both demand-valve systems and continuous flow systems. Appropriate assessment criteria have been worked out; the course of the test and the results for two ventilators are discussed as an example, using these criteria.  相似文献   

7.
BACKGROUND: Stereotactic procedures employing frame-based systems and utilizing pre-operative MR or CT have several shortcomings such as long procedure time, patient discomfort and transport, poor fail-safe capabilities and targeting inaccuracies due to brain shift. Conducting all procedural steps in an interventional MRI has the potential of alleviating some of these deficiencies. METHODS: A stereotactic system consisting of a skull-mounted mechanical positioning device and customized navigation software has been developed. The accuracy of this system was tested within an interventional MRI employing a skull phantom. RESULTS: The mean distance between the targets hit and the planned target coordinates was 0.70 mm +/- 0.3 mm with a maximum distance of 1.3 mm. INTERPRETATION: The results indicate that the proposed stereotactic system can be used for stereotactic procedures in the interventional MRI.  相似文献   

8.
The cuffed oropharyngeal airway is a new disposable airway based on the Guedel oral airway. It has an asymmetrical cuff which provides a seal as well as lifting the base of the tongue forwards, and a 15-mm connector allowing attachment to an anaesthetic breathing system. The device does not extend beyond the vallecula, so that the laryngeal inlet can be visualised with a fibreoptic laryngoscope passed between the cuff of the device and the pharyngeal wall. The advantage is that ventilation is maintained throughout the intubating sequence. We describe its use in a patient with oropharyngeal carcinoma.  相似文献   

9.
The non-zero basal flow (BF) of oxygen in anesthesia machines has been set to supply the basal metabolic requirement of oxygen. However, there is no scientific evidence of its necessity. In this study we sought to clarify whether non-zero BF affects leak detection during preanesthetic inspections. Twenty-five participants performed leak tests on anesthesia machines to detect breathing circuit leaks. Artificial leak-producing devices were used to create leaks from 0 to 1.0 L/min. The investigator randomly chose the leak device and connected it into the breathing circuit. Participants, blinded as to the presence or the type of leak producing device, then tested the breathing circuit for leaks. The conventional breathing system leak test was performed with and without BF. The results of leak detection in each leak procedure were analyzed statistically. The leak detection rate of leak test with BF was less than without BF (P < 0.01). We demonstrated that non-zero BF of oxygen decreases the leak detection rate and is an obstacle for leak detection, especially for small leaks. Therefore, we recommend that breathing circuit leak tests should be performed in the absence of BF of oxygen.  相似文献   

10.
Heat and moisture exchangers (HMEs) humidify, warm and filter inspired gas, protecting patients and apparatus during anaesthesia. Their incorporation into paediatric anaesthetic breathing systems is recommended. We experienced delays in inhalational induction whilst using a Mapleson F breathing system with an HME. We have demonstrated that the HME significantly alters gas flow within the breathing system. Approximately half of the fresh gas flow is delivered to the patient, the remainder being wasted into the expiratory limb of the breathing system. We suggest that the HME should be removed from the Mapleson F breathing system until inhalational induction is complete, or that the reservoir bag is completely occluded until an effective seal is obtained with the mask.  相似文献   

11.
The quality of life of patients after radical prostatectomy is mainly influenced by erectile dysfunction (ED) and incontinence. New criteria for treatment and patient selection give us the opportunity to restore sexual function in more patients.When ED is present, we should not wait for 24 months for natural restitution. PDE-5-inhibitors, intracavernosal self injection therapy and the vacuum constriction device are effective and conform to both patient and economic preference.Therefore, every urologists should be able to offer his patients an individual and successful approach to the therapy of ED after prostate cancer.  相似文献   

12.
This is an investigation of a technique for simultaneously measuring arterial oxygen tension (PaO2) and blood pressure continuously during and after surgical anesthesia. In 27 patients, a special T attachment was placed on the end of an indwelling arterial catheter so that pressurized dilute heparin could be flushed through continuously while blood pressure was being recorded by means of a transducer-oscilloscope system and PaO2 was being recorded through an indwelling polarograph oxygen tension (PO2) readout device. The electrode was left in the artery for an average of 16 hours; the average PaO2 during mechanical ventilation with the patient breathing 50 per cent oxygen was approximately 200 torr at the beginning of anesthesia; it dropped to 158 torr 6 hours later. The average PaO2 in the recovery room 1 hour postoperatively, with the patient spontaneously breathing approximately 30 per cent oxygen, was 122 torr. No significant complications were encountered during this investigation. We believe this dual technique to be a valuable monitoring tandem in the anesthetized and surgical intensive care patient.  相似文献   

13.
A new type of airway has been widely used for two years, throughout hospitals in the United Kingdom. Designed and created since 1983 by Dr AIJ Brain, the Laryngeal Mask Airway (LMA) is a compromise between the endotracheal tube and the face-mask. Blindly inserted in an anaesthetized patient, without either a laryngoscope or neuromuscular blockade, it provides a good airway in almost all cases. It is often able to offer an effective alternative to difficult intubation. The LMA can be used with either spontaneous or positive pressure ventilation. Because it doesn't provide a reliable protection of the airway from aspiration, it should never be used in the patient with a full stomach. The spontaneously breathing patient, undergoing elective surgery for 15 to 60 minutes, in supine position, who would ordinarily be managed with a face-mask is the more likely candidate for the LMA. But, longer procedures, in lateral or prone position, with controlled ventilation can usually be carried out using the Brain's device. More effective and less demanding than the facial-mask, much less hurtful than the endotracheal tube, the Laryngeal Mask is potentially an important and valuable addition to anaesthetic care.  相似文献   

14.
B. E. SMITH 《Anaesthesia》1985,40(8):790-796
The Penlon Bromsgrove is a new high frequency jet ventilator, suitable for use in both adults and children. The jet stream is humidified by means of an integral in-line Bernoulli nebuliser. The self-recharging nebuliser can also convey drugs directly to the airways in the form of an aerosol. Alarms and fail-safe systems are incorporated. A pressure gauge continuously displays the jet drive pressure. There are two digital LED displays; one shows jet frequency in breaths per minute; the other, the jet drive pressure, minimum, maximum and mean patient airway pressures. Two fail-safe systems ensure that these pressures do not become excessive. Both audible and visual alarms are provided. The prototype has proved to be quiet and completely reliable over more than 4000 hours use, with no bronchoscopic or histological evidence of ineffective humidification.  相似文献   

15.
We report an unexpected ventilation difficulty with an anesthetic breathing circuit in a pediatric patient receiving left herniorrhaphy. A manufacturing defect in a limb of the anesthetic breathing circuit caused this problem. This defect induced a high-pitched, wheezing-like sound, which was difficult to differentiate from a hyper-reactive airway, commonly seen in pediatric patients with recent upper respiratory tract infection. We recommend that the patency of the anesthetic breathing circuit should routinely be examined before connecting it to the anesthesia machine.  相似文献   

16.
M. KLAIN  R. B. SMITH 《Anaesthesia》1976,31(6):750-757
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17.
A cuffed oropharyngeal airway (COPA) was used in 20 adult patients for airway management under epidural and brachial plexus block supplemented with light general anesthesia. Insertion of a COPA was successful at first attempt in 17 of 20 patients (85%). Sore throat developed in one patient (5%). Aspiration regurgitation, or laryngospasm was not observed. We conclude that a COPA can be an efficient airway device is spontaneously breathing patients under anesthesia.  相似文献   

18.
The new anaesthetic conserving device (ACD) allows the use of isoflurane and sevoflurane without classical anaesthesia workstations. Volatile anaesthetic exhaled by the patient is absorbed by a reflector and released to the patient during the next inspiration. Liquid anaesthetic is delivered via a syringe pump. Currently the use of the ACD is spreading among European intensive care units (ICU). This article focuses on the functioning of the device and on particularities which are important to consider. The ACD constantly reflects 90% of the exhaled anaesthetic back to the patient, but if one exhaled breath contains more than 10 ml of anaesthetic vapour (e.g. >1 vol% in 1,000 ml), the capacity of the reflector will be exceeded and relatively more anaesthetic will be lost to the patient. This spill over decreases efficiency but it also contributes to safety as very high concentrations are averted. Compared to classical anaesthesia systems the ACD used in conjunction with ICU ventilators offers advantages in the ICU setting: investment costs are low, carbon dioxide absorbent is not needed, breathing comfort is higher, anaesthetic consumption is low (equal to an anaesthesia circuit with a fresh gas flow of approximately 1 l/min) and anaesthetic concentrations can be controlled very quickly (increased by small boluses and decreased by removal of the ACD). On the other hand, case costs are higher (single patient use) and a dead space of 100 ml is added. There are pitfalls: by a process called auto-pumping, expansion of bubbles inside the syringe may lead to uncontrolled anaesthetic delivery. Auto-pumping is provoked by high positioning of the syringe pump, heat and prior cooling of the liquid anaesthetic. Inherent to the device is an early inspiratory concentration peak and an end-inspiratory dip which may mislead commonly used gas monitors. Workplace concentrations can be minimized by proper handling, a sufficient turnover of room air is important and gas from the expiration port of the ventilator should be scavenged. Inhalational compared to intravenous ICU sedation offers the advantages of better control of the sedation level, online drug monitoring, no accumulation in patients with renal or hepatic insufficiency and bronchodilation. With a lowered opioid dose spontaneous breathing and intestinal motility are well preserved. A clinical algorithm for the care of patients with respiratory insufficiency including inhalational sedation is proposed. Inhalational sedation with isoflurane has been widely used for more than 20 years in many countries and even for periods of up to several weeks. In the German S3 guidelines for the management of analgesia, sedation and delirium in intensive care (Martin et al. 2010), inhalational sedation is mentioned as an alternative sedation method for patients ventilated via an endotracheal tube or a tracheal cannula. Nevertheless, isoflurane is not officially licensed for ICU sedation and its use is under the responsibility of the prescribing physician.  相似文献   

19.
A comprehensive anesthetic plan for managing patients undergoing "awake: intracranial surgery (AICS) must include a means of rescuing the patient if the airway becomes obstructed. Since access to the patient's airway is limited, mask ventilation can be challenging and laryngoscopy and tracheal intubation, impossible. The need exists for an alternative airway device that is easy to insert, would allow controlled ventilation, and would facilitate a smooth emergence with minimal coughing. The cuffed oropharyngeal airway (COPA) was introduced as a supraglottic airway device in spontaneously breathing patients. The authors report their preliminary experience of its use in AICS. The COPA was inserted in 20 patients on 31 occasions. Insertion of the COPA was accomplished easily at the first attempt in all cases irrespective of patient position. Airway maneuvers were required when patients were supine but not lateral. The COPA is a useful device to instrument the airway in patients undergoing AICS using the asleep-awake-asleep technique in the lateral position.  相似文献   

20.
Atrial septal defects can be closed surgically or percutaneously. We report a patient who underwent percutaneous closure of an atrial septal defect with an Amplatzer septal occluder device (AGA Medical Corp, Golden Valley, MN). The patient presented 4 months later with congestive heart failure secondary to an erosion of the Amplatzer septal occluder into the aortic root. The device was removed surgically, and the fistula was repaired. Amplatzer septal occluder indications, selection criteria, and complications are discussed.  相似文献   

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