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W E Spoerel

Publications and source records attributed to W E Spoerel.

17 recordsLinked to original sources
PubMed1990

Re-evaluation of the Farman entrainer in a low-pressure system for field anaesthesia.

The aim of this project was to develop a portable anaesthesia system that was compatible with modern anaesthesia practice under field conditions, when compressed gas supplies are limited. We assembled and evaluated a low-pressure plenum system, based upon the Farman entrainer, which was adaptable to spontaneous, assisted or intermittent positive pressure ventilation (IPPV). The entrainer was tested using a low flow of compressed gas, O2 at 1-3 L.min-1. We measured the fresh gas flow (FGF) and O2 concentrations (F1O2) delivered at various source gas flow rates (O2 flow), and with various breathing circuits. Entrainment ratio, FGF, and F1O2 were highly dependent upon resistance to flow in the different breathing circuits. With a wide bore T-piece the air/O2 entrainment ratio was 6:1, and the F1O2 was 0.3. When circuit resistance was higher, e.g., with the Bain circuit, air entrainment and FGF were reduced, but F1O2 was higher. Because it offered the lowest resistance, the T-piece circuit was selected for a clinical trial.

Anesthesia, Inhalation↗
PubMed1990

A low-pressure portable anaesthesia system for field use: clinical trials.

This is a report of our experience with a portable anaesthesia system that was developed for use under field conditions, when compressed gas supplies are limited. We first assembled and bench-tested a low-pressure plenum system, based upon the Farman entrainer. The entrainer required a low flow of compressed gas, O2 at 1-2 L.min-1, and generated a low-pressure mixture of O2 and air which was directed through an Oxford miniature vaporizer, a non-return valve, and a widebore T-piece circuit. With this system we anaesthetized 24 patients with intermittent positive pressure ventilation (IPPV) and nine patients breathing spontaneously. During IPPV, the circuit resembled a T-piece and provided effective gas exchange with a FGF of 1.2 times minute ventilation. Inspiratory and expiratory valves were arranged so that the spontaneous mode was non-rebreathing, and FGF was adjusted to equal minute ventilation. The system was very economical, using 1-2 L.min-1 O2 and 20-25 ml.hr-1 liquid halothane to produce a FGF of 6-10 L.min-1, an FIO2 of 0.33, and FIhal of 1-1.5 per cent. We have demonstrated that this is a versatile, safe, and economical system, compatible with the practice of modern inhalational anaesthesia under field conditions. It can be readily assembled from commercially available components.

Adult↗
PubMed1979

A proximal system for positive end-expiratory pressure (PEEP) and continuous positive airway pressure (CPAP).

A proximal positive end-expiratory pressure (PEEP) and continuous positive airway pressure (CPAP) system was constructed by the simple addition of a venturi T-piece proximal to the exhalation limb of a breathing circuit. The level of PEEP or CPAP was determined by the amount of flow powering the venturi. This system can provide positive pressure in excess of 40 cm H2O without the need for check valves, dump valves or additional nebuliers and flowmeters.

Humans↗
PubMed1979

Bain circuit.

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Anesthesia↗
PubMed1977

Carbon dioxide output and elimination in children under anaesthesia.

The requirements for fresh gas inflow with the Bain breathing circuit in children was examined by determining the PaCO2 in 46 children during controlled ventilation with a total fresh gas inflow of 3.5 l/min and by measuring the carbon dioxide output in 83 children under anaesthesia. It could be shown that all children below 40 kg body weight had a PaCO2 below 40 torr (5.32 kPa) and the PaCO2 paralleled the body weight, i.e., the lowest carbon dioxide tension was seen in children under 10 kg. As expected, the highest carbon dioxide output was found in children below 5 kg body weight; the carbon dioxide output per kilogram decreased with increasing body weight up to 30-35 kg and remained at that level in larger children. Children in their teens, although they may have attained adult body weight, had a higher carbon dioxide output than adults. Based on these findings, our recommendation of a total fresh gas inflow of 3.5 1/min for all children would appear adequate for a body weight up to 35 kg on controlled ventilation. In children under 10 kg body weight, a reduction of the total fresh gas flow to two litres per minute will avoid marked respiratory alkalosis. For children over 35 kg, a fresh gas flow of 100 ml/kg/min should be satisfactory during controlled ventilation.

Adolescent↗
PubMed1976

Carbon dioxide output in anaesthesia.

In a Mapleson D circuit the carbon dioxide content of gases, sampled at the breathing bag or near the bellows of the ventilator, is virtually constant throughout the phases of respiration. Assuming that after induction of anaesthesia the fresh gas inflow, if kept constant, is essentially equal in volume to the gas vented at the expiratory valve, CO2 output can be calculated by multiplying the fresh gas inflow by the CO2 content of the vented gas measured with a suitable CO2 analyzer. Anaesthesia with nitrous oxide-oxygen, supplemented with low doses of alphaprodine or halothane was compared in two groups of young patients who underwent dental surgery and who were breathing spontaneously. While the CO2 output in the group supplemented with alphaprodine increased from about 100 to 130 ml/m2/min, the halothane group showed a constant CO2 output of about 90 ml/m2/min followed by a significant rise within 5 minutes after halothane was discontinued. In 42 patients on controlled ventilation, no significant difference was found in the CO2 output estimated one hour after induction of anaesthesia in nitrous oxide-oxygen anaesthesia supplemented by halothane, ethrane or alphaprodine. The values obtained were 87 +/- 11 ml/m2/min for halothane (11 patients), 98 +/- 19 ml/m2/min for ethrane (14) and 93 +/- 13 ml/m2/min for the narcotic supplemented anaesthesia (17). The mean CO2 output for all 42 patients was 93 +/- 14 ml/m2/min. Six markedly obese patients under the same anaesthetic technique had a CO2 output of 114 +/- 17 ml/m2/min; however, their CO2 output was similar to normal patients when calculated on the basis of body weight. A marked increase in CO2 output to a mean of 160 +/- 25 ml/m2/min was found in eight patients undergoing operation while on hyperalimentation. The technique described appears suitable to monitor CO2 output under anaesthesia. In order to avoid hypercarbia when using a partial rebreathing system, the fresh gas inflow must be increased above recommended values in cases with increased metabolic activity (e.g. patients receiving hyperalimentation). In obese patients the fresh gas inflow should be calculated on the basis of body weight.

Adult↗
PubMed1976

Acupuncture in chronic pain.

A course of 10 daily acupuncture treatments was given to 200 patients who suffered from chronic pain syndromes of at least one year duration and the result assessed at the end of the course of treatment and after an interval of at least 2 months. Treatments were individualized using needling of body loci distally and near the site of pain, and ear acupuncture. In 38 patients suffering from chronic headaches, including 13 cases of migraine-type headache, 81% reported an improvement in their condition, but only one patient was pain free for the 2-month observation period. In 162 patients with other chronic pain problems, 99 or 61% were improved or pain free at the end of treatment; in 69 of these a worthwhile degree of improvement persisted over the observation period of 2 months. Thirteen percent of all patients did not respond to acupuncture and in 26% the response was considered as transient only. Daily treatments are not more effective than weekly or biweekly treatments. Pain in the neck and shoulder region, in the knee and low back pain responded to acupuncture with prolonged improvement in over 50% of the patients treated. Facial pain syndromes and pain in the region of the trunk were least responsive and only 3 of 11 patients with post-herpetic neuralgia reported still having less pain after 2 months. Needling of effective loci and particularly ear needling often causes an instantaneous reduction or disappearance of pain; the speed of this response can only be explained by a mechanism within the nervous system. Based on our experience acupuncture represents a useful therapeutic modality in the management of pain.

Abdomen↗
PubMed1976

[Acupuncture analgesia in China (author's transl)].

As part of an agreement between the Governments of the People's Republic of China and Canada, 10 Canadian Anaesthetists visited China for six weeks during April and May 1974. The delegation observed 87 surgical operations and 19 dental procedures conducted under acupuncture analgesia in 17 large hospital in Peking, Schichiachuang, Nanking, Shanghai and Canton. In this report, observations on acupuncture analgesia made during this visit are presented as well as information obtained in group discussions with Chinese physicians. In the author's opinion, the technique was successful in about 80% of the cases seen; these patients were awake during surgery without visible distress and exhibited a remarkable degree of analgesia immediately after surgery. However, in China, acupuncture analgesia is still considered in the experimental stage and only used in a limited number of standardized, elective surgical procedures, where confidence and the success of this technique have been established. For the successful use of this technique, patient and surgeon must co-operate fully. Acupuncture analgesia poses considerable limitations on the surgeon and requires careful surgical technique; the patient's co-operation must be assured by a suitable preparation. It appears, that acupuncture analgesia should be seen as an alternative to local anaesthesia rather than general anaesthesia; the latter is only used to a limited extent in China. In our present anaesthetic practice, acupuncture would appear to be of only very limited use, however, a further study of this phenomenon should contribute to our knowledge of the function of the nervous system.

Acupuncture Therapy↗
PubMed1975

Prediction of arterial carbon dioxide tension during controlled ventilation with a modified Mapleson D system.

Based on measurements of arterial CO2 tension in 132 adult patients, a curve was constructed relating fresh gas inflow and arterial CO2 tension for a modified Mapleson D system. In patients on controlled ventilation using a ventilating volume greater than the predicted respiratory minute volume, it was found that the arterial Pco2 can be predicted from the fresh gas inflow with an accuracy sufficient to be clinically useful.

Adult↗
PubMed1975

Direct arterial pressure monitoring from the dorsalis pedis artery.

The arteria dorsalis pedis, when clearly palpable, is a suitable artery for direct arterial blood pressure monitoring. The systolic pressure and the pulse pressure are likely higher in the dorsalis pedis artery when compared to the radial artery but there is no clinically significant difference in mean pressures. In plethysmographic studies it was found that in 16 per cent of the patients examined the pulse in the second toe disappeared after occlusion of the dorsalis pedis artery indicating that it carried the main blood supply to the toes. Although no complications have resulted from cannulation of the dorsalis pedis artery in our practise, some caution is in order and preliminary testing may be advisable even if the posterior tibial artery is distinctly palpable.

Adult↗
PubMed1975

Acupuncture analgesia in China.

A delegation of ten Canadian anaesthetists visited the People's Republic of China in April and May 1974 and observed 87 surgical and 19 dental operations under acupuncture analgesia. In 80% of the cases observed the analgesia appeared adequate for the conduct of the planned surgery. The utilization of acupuncture analgesia varied from hospital to hospital; surgeons and anaesthetists appeared to have confidence in using it in a limited number of planned surgical operations. The technique of induction varied from hospital to hospital, but a certain pattern became apparent; body needling was related to the site of operation and also based on ancient theories; using loci unrelated to the operative site, para-incisional needles were used to produce skin analgesia; ear needling alone was used in 19 cases and nose needling in one. No premedication was given for short cases and dental extractions. Most hospitals used electrical stimulation; in one institution needles were left in place during induction and throughout surgery without stimulation with equal results. A considerable degree of analgesia appeared to be present immediately post-operative and patients moved without concern for the operative site. It was felt that acupuncture analgesia represents n China an alternative to regional anaesthesia and that surgeons adapt their technique to the conscious patient in the operating room. It is essential that the patient cooperate and is prepared and motivated to withstand the emotional stress and unpleasant sensations associated with the surgery. Problems include inadequate suppression of visceral pain, lack of muscle relaxation and inadequate analgesia. In the author's opinion acupuncture analgesia has a very limited scope in our practice; it is time consuming and imposes considerable restrictions on the surgeon. However, the phenomenon is real and its investigation should contribute to a better understanding of the function of the nervous system.

Acupuncture Therapy↗