摘要:

Urinary excretion of catecholamines was determined separately during the first stage of labour and during the period from the beginning of the second stage until 1/2 h after delivery in 16 healthy mothers, whose labours were induced at term. Seven mothers were given segmental epidural analgesia, at the height of Th10–12, to achieve complete pain relief during the first stage of labour. The remaining parturients served as controls. During the first stage of labour the urinary excretion rate of catecholamines was at the normal nongravid rest level in both groups. During the second stage, and 1/2 h after the delivery, the amount of urinary catecholamines increased significantly in both groups. The latter values corresponded to the amounts of catecholamines excreted during heavy physical wor

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1977.tb01193.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The respiratory centre is a multi‐input system and positive‐pressure ventilation is known to interfere with respiratory control mechanisms. Further, in intermittent positive‐pressure ventilation (IPPV) the ventilatory pattern produced by the ventilator and the lung systems is known to influence pulmonary and cardiovascular functions. High‐frequency positive‐pressure ventilation (HFPPV) has been shown to eliminate respiration‐synchronous variations in blood pressure and blood flow, and at frequencies of 60 per min or more spontaneous breathing ceases almost instantaneously if adequate alveolar ventilation and arterial oxygenation are achieved. However, activation of other inputs to the respiratory centre, e.g. chemo‐receptor inputs, can induce spontaneous respiration during HFPPV. Consequently the balance between excitatory and inhibitory afferents is decisive for the patient's spontaneous respiratory efforts (discoordination) during artificial ventilation.The balance between excitatory and inhibitory mechanisms during artificial ventilation is illustrated in two patients with pulmonary insufficiency. Both patients exhibited spontaneous respiratory efforts (discoordination) during ventilation with a “conventional” type of respirator (ventilatory frequency 20 per min) despite adequate alveolar ventilation, adequate arterial oxygenation and administration of sedatives and respiratory depressants. During HFPPV, at ventilatory frequencies of 60 per min or more, there was an inhibitory effect on spontaneous respiration, and with adequate alveolar ventilation and adequate arterial oxygenation (obtained at lower inspiratory airway pressures than with a “conventional” type of ventilation) it was possible to discontinue sedatives and respiratory depressants without discoordination occurring between the patient and the ventilator. However, in one of the patients, with decreasing pulmonary compliance and diminishing arterial oxygenation (due to increasing intrapulmonary shunting and cardiac decompensation), spontaneous respiratory efforts were present despite high ventilatory frequencies and administration of sedatives and respiratory depressants.From experimental investigations reported elsewhere, this study in two patients and similar experience in other patients, it seems that it is easier to adapt a patient to a ventilator which has a negligible compression volume and which is se

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1977.tb01262.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The necessity of providing alkalizing therapy after re‐establishment of the local circulation was studied in 10 otherwise healthy patients with intermittent claudication. No such necessity was found in providing stable peroperative circulation, normo‐ to slight hypothermia, adequate infusions, and normal acid‐base values prior to arterial clamping.It is pointed out that alkalosis can cause circulatory problems that are just as serious as those occurring with acidosis; therefore the routine use of alkalizing agents during vascular surgery is inadvisable. Should unstable circulatory parameters occur and hypoperfusion be suspected, then repeated control of the acid‐base values is in

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1977.tb01195.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Caesarean section was performed in 10 patients under general anaesthesia and in 10 other patients under epidural block. The foetal heart rate was monitored continuously during anaesthesia and operation with a scalp electrode and a cardio‐tocograph. There was no major difference between the two anaesthetic techniques in their effect on the foetal heart rate. The most common finding was a reduction of the beat‐to‐beat variation. The operative time was longer in the epidural group than in the general anaesthesia group, due to a higher frequency of Pfannenstiel incisions and repeat caesarean sections in the epidural group. Clinically, all newborns seemed to be unaffected, with normal Apgar scores. Epidural block seems to be a good alternative to general anaesthesia for caesarean section, particularly when a long operative time is exp

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1977.tb01196.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Techniques for ventilation in bronchoscopy under general anaesthesia using intermittent positive‐pressure ventilation directly via the fixed side‐arm of the open bronchoscope have recently been described by several authors. Our present technique utilizes a high pressure oxygen/nitrous oxide gas mixture which is obtained from a gas‐conditioning system. This gas is intermittently supplied at a high insufflation frequency to the side‐arm of the open bronchoscope.In lung model experiments and experiments in dogs the use of Storz bronchoscopes 4–9 mm in diameter was studied. With the volumes of delivered gas kept constant, the lung model studies showed that the “intrapulmonary pressure” increases with decreasing insufflation frequencies; in parallel the “pulmonary ventilation” decreases due to increasing gas loss through the outer opening of the open bronchoscope. In both the dog and the lung model experiments increasing frequencies resulted in reduced pulmonary ventilation. Both of these studies showed that when the relative insufflation time was shortened from 32 to 22 % of the period time ventilation increased. As demonstrated previously, the central venous pressure and the pulmonary arterial pressure were not affected by this type of high‐frequency positive‐pressure ventilation.It is concluded that this study favours an insufflation frequency (f) of 60 per min and a relative insufflation time (t%) of 22% to be used in the clinical situation.If f/t% is kept at 60/22 inbronchoscopic HFPPVthe driving gas pressure is the principal determinant of the total gas input and pneumatic valve function, which are the main factors in the generation of tidal volume and alveolar ventilation with this “open” ventilator system. Consequently, and as may be demonstrated clinically (Eriksson&Sjöstrand1977a), the ventilation of the patient is regulated by the driving gas pressure. As there is no air entrainment with bronchoscopic HFPPV the oxygenation is regulated by means of the oxygen concentration in the oxygen/ nitrous oxide mixture delivered intermittently to the si

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1977.tb01263.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The incidences of electrocardiographic (ECG) changes during microlaryngoscopy under halothane anaesthesia were compared by using Althesin® and thiopentone as induction agents.During the procedure the most common ECG change in both groups was junctional rhythm, which occurred in 37% of the patients in the Althesin group and in 29% of the patients in the thiopentone group. The next most common changes in the Althesin group were: ventricular ectopic beats (22%), ischaemic S‐T segment depression (14%), and T wave flattening or inversion (14%); those in the thiopentone group were ventricular ectopic beats (18%) and rapidly ascending S‐T segment depression (12%). As well as during the procedure, some ECG changes were registered in both groups during intubation. ECG changes disappeared without any special treatment after manipulation of the vocal cords or after intubation.There was no statistically significant difference in the total incidence of dysrhythmias between the Althesin and thiopentone groups, but the types of dysrhythmias were different in the two groups. There were more lower nodal rhythms, less serious ectopic beats and more ischaemic S‐T segment depression in the Althesin group than in the thiopentone group.The results suggest that Althesin is useful and superior to thiopentone in patients with a tendency to develop serious ventricular ectopic beats, whereas in patients with heart and coronary arterial disease, Althesin is inferior to thiopentone and should be used wit

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1977.tb01197.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

A technique for automatic ventilation in bronchoscopy under general anaesthesia was evaluated in two types of lung model and in 23 patients (29–70 y) submitted for routine bronchoscopy. The technique uses high‐frequency positive‐pressure ventilation (HFPPV) and functions with a pneumatic valve derived from the bronchoscope's side‐arm. This technique has been given the namebronchoscopic HFPPV.Based on earlier studies, an insufflation frequency (f) of 60 per min and a relative insufflation time (1%) of 22 % was used.In the lung models, the relationship between the total gas input (Vtot) delivered to the side‐arm of the bronchoscope and the pressure/gas flow pattern created at the different openings of the bronchoscope was studied. The force created by the pneumatic valve function is regulated by adjustment of Vtotand implies a great ventilatory reserve capacity. No air entrainment occurs through the proximal opening of the bronchoscope, which implies full control of the anaesthetic gas mixture delivered to the patient.Many of the patients were considered to be high anaesthetic risks and in the patient study it is shown that the alveolar ventilation can be fully controlled by adjustment of VTOTand arterial oxygenation by adjustment of the oxygen concentration of the oxygen/nitrous oxide mixture delivered to the side‐arm of the bronchoscope.Experimental and clinical evaluation shows that adequate oxygenation and ventilation can be achieved: —(a) over long periods of time,(b) in anaesthetic high risk patients,(c) with the bronchoscope in the main bronchus of the diseased lung, and(d) during instrumentation through the bronchoscope.A simple ventilation‐nomogram for clinical use is proposed. Adequately used, this nomogram guarantees safe ventilation during bronchoscopic HFPPV. An FIO2of 0.3–0.4 gives adeq

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1977.tb01264.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

A technique for automatic ventilation during laryngoscopy under general anaesthesia was evaluated in a lung model and in 5 patients (3–57 y) submitted for routine laryngoscopy. This technique has been given the namelaryngoscopy HFPPVand utilizes an insufflation frequency (f) of 60 per min and a relative insufflation time (t%) of 22%. Ventilation is given via a nasotracheal insufflation catheter.Laryngoscopy HFPPV permits laryngeal surgery with a virtually unobstructed surgical field under complete muscular relaxation. The alveolar ventilation of the patient may be controlled by adjustment of the pressure of the anaesthetic gas mixture and there is no air entrainment through the larynx during insufflation. This makes possible use of O 2/N 2 O mixtures and the oxygenation of the patient may be controlled by adjustment of the oxygen concentration of the anaesthetic gas mixture. As there is a continuous upward gas flow through the larynx, blood or pieces of loose tissue are not sucked down into the trachea.A simple ventilation nomogram for clinical use is proposed. Adequately used, this nomogram guarantees safe ventilation during laryngoscopy HFPPV. An FIO2of 0.3–0.4 gives adequate arterial oxygenat

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1977.tb01265.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The low pulmonary compliance, the high airway resistance and the “rapid” breathing pattern of neonatal and paediatric patients make it necessary to design special ventilators to match the pulmonary physiology of infants.A ventilator system which also in small children has a negligible compression volume was evaluated in a lung model and during repair of cleft lip and palate in 16 patients under general anaesthesia and in two other infants during other operations. High‐frequency positive‐pressure ventilation (HFPPV) was given with an insufflation frequency (f) of 60 per min and a relative insufflation time (t%) of 32%. In addition, two neonates treated postoperatively with HFPPV are reported.Despite the “open” character of the ventilator system both intra‐ and postoperative ventilation were uneventful in all patients. The arterial oxygenation was good in all cases, as judged from clinical signs or blood gas analyses. Postoperative ventilation required conventional clinical observation and intermittent analyses of blood.HFPPV has been shown to depress, or abolish, spontaneous respiration via reflex mechanisms. In all patients in this investigation respiratory movements were absent at normo‐ or slight hyperventilati

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1977.tb01266.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Some respiratory, circulatory and clinical conditions are reviewed in connection with the use of ventilator systems for intermittent positive‐pressure ventilation at a normal frequency (IPPV‐nf). Intermittent positive‐pressure ventilation with considerably higher frequencies (IPPV‐hf) can, with an appropriate pressure and flow pattern (but at the cost of an increased dead space ventilation) provide adequate alveolar ventilation. The type of IPPV‐hf that has been given the namehigh‐frequency positive‐pressure ventilation (HFPPV)gives a ventilatory pressure/flow pattern that interferes less with circulatory function than IPPV‐nf. Furthermore, the ventilatory pattern of HFPPV has been found to have desirable respiratory and other systemic effects, making this form of artificial ventilation of clinical interest. However, before HFPPV could be considered sufficiently well developed for routine clinical use, further technical refinement and simplification were necessary and the technical, functional and clinical demands on systems for modern respiratory care are therefore discussed.The ventilatory and circulatory implications of the ventilatory pressure/flow patterns generated in HFPPV have been investigated with previously described ventilator systems for HFPPV, and this has been the subject of separate reports.Under conditions of high airway resistance and low compliance, volume‐controlled respirator systems are required for efficient artificial ventilation. Satisfactory volume‐controlled ventilation can, however, only be obtained by using systems with a small compressible volume and low internal compliance. Three ventilator systems satisfying these two criteria are described and with these prototype systems for volume‐controlled IPPV the ventilatory pressure/flow pattern of HFPPV may be obtained, i.e.volume‐controlled HFPPVis achieved. Further, these prototype systems are versatile in the respect that they are both able to give (a) volume‐controlled IPPV‐nf or IPPV‐hf (HFPPV), and (b) continuous positive‐pressure breathing in the neonate (CPAP) or in the adult (CPAP or CPPB).One of the prototype systems has been developed for neonatal intensive care. It has been studied experimentally in a lung model and is used routinely for clinical treatment of neonatal respiratory distress; preliminary clinical reports have been presented previously. The other prototype systems presented have been developed according to the same principles for intensive respiratory care of adults, but they have not yet been used clinically.The effects of the pressure/flow pattern of the ventilatory systems described in this communication—i.e. pressure/flow‐generated volume‐controlled HFPPV—has been studied in dog experiments and compared with the ventilatory pattern of a conventional respirator system and this wil

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1977.tb01267.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY