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1.
Respir Med ; 88(9): 665-8, 1994 Oct.
Article in English | MEDLINE | ID: mdl-7809438

ABSTRACT

Patients who smoke heavily and those with pre-existing airflow obstruction are at particular risk of postoperative respiratory infection following upper abdominal surgery. This invariably prolongs hospital stay and increases morbidity. In order to determine whether high dose bronchodilator therapy in the perioperative period reduced the risk of infection, all patients undergoing elective upper abdominal surgery were assessed for risk of developing postoperative infection. Fifty-three patients were identified as high risk according to previously published criteria and were randomly allocated to receive nebulized salbutamol (5 mg) or saline placebo 6 hourly for 48 h beginning 1 h preoperatively. There was no difference in rates of postoperative chest infection in the two groups and this study, therefore, provides no support for the routine preoperative use of bronchodilators in these patients.


Subject(s)
Albuterol/administration & dosage , Lung Diseases/prevention & control , Postoperative Complications/prevention & control , Respiratory Tract Infections/prevention & control , Aged , Double-Blind Method , Female , Humans , Male , Middle Aged , Nebulizers and Vaporizers , Premedication
2.
Clin Sci (Lond) ; 78(3): 311-3, 1990 Mar.
Article in English | MEDLINE | ID: mdl-2156651

ABSTRACT

1. After a run-in period, six healthy, recumbent, water-loaded male subjects breathed through an inspiratory threshold load for 90 min. To correct for prolonged recumbency, a similar protocol was followed on a separate control day, but without an inspiratory load. 2. A negative intrathoracic pressure of at least 30 cmH2O was required to overcome the threshold load. 3. Urine was collected every 30 min and analysed for sodium concentration. 4. Plasma samples were collected every 30 min and analysed for atrial natriuretic peptide concentration. 5. The inspiratory load had no effect on urine volume, urinary sodium excretion or plasma atrial natriuretic peptide levels.


Subject(s)
Atrial Natriuretic Factor/blood , Respiration/physiology , Adult , Humans , Inspiratory Capacity/physiology , Male , Sodium/urine , Time Factors
3.
Lancet ; 335(8684): 249-53, 1990 Feb 03.
Article in English | MEDLINE | ID: mdl-1967719

ABSTRACT

61 snoring children selected for adenotonsillectomy, mainly for recurrent tonsillitis, were compared with a matched group of 31 healthy children for symptoms of sleep apnoea, extent of sleep hypoxaemia, and amount of sleep disturbance. The studies were repeated six months postoperatively, and after six months in the healthy children. Preoperatively, 61% of the children had degrees of sleep hypoxaemia above normal and 65% had abnormally disturbed sleep. A questionnaire administered to the parents about their children showed abnormal patterns of answers about sleep problems daytime sleepiness, hyperactivity, aggression, learning difficulties, restless sleep, and odd sleeping positions. After adenotonsillectomy, the abnormal hypoxaemia, excessive sleep disturbance, and multiple symptoms almost resolved; a growth spurt also occurred.


Subject(s)
Adenoidectomy , Hypoxia/complications , Sleep Apnea Syndromes/surgery , Tonsillectomy , Adolescent , Body Weight , Child , Child, Preschool , Circadian Rhythm , Evaluation Studies as Topic , Female , Follow-Up Studies , Growth , Humans , Hypoxia/physiopathology , Male , Oximetry , Prospective Studies , Pulse , Recurrence , Sleep Apnea Syndromes/complications , Sleep Apnea Syndromes/physiopathology , Snoring/physiopathology , Surveys and Questionnaires , Tonsillitis/complications , Tonsillitis/surgery , Video Recording
4.
Q J Med ; 68(256): 637-44, 1988 Aug.
Article in English | MEDLINE | ID: mdl-3255985

ABSTRACT

Thirty men (aged 35-65) with untreated essential hypertension (BP greater than or equal to 140/90), confirmed by 24-h ambulatory monitoring, had overnight recordings of arterial oxygen saturation (SaO2) in their own homes. The overnight saturation records were compared with those from a group of 30 normotensive control subjects matched for age, height and weight. The groups did not exhibit significant differences in any of the following parameters of overnight oxygenation: median SaO2, lowest SaO2 or frequency of 3 or 4 per cent dips in SaO2. We conclude that essential hypertension is not associated with excessive arterial hypoxaemia such as might be due to a sleep apnoea syndrome.


Subject(s)
Hypertension/complications , Hypoxia/complications , Adult , Aged , Humans , Male , Middle Aged
5.
J Appl Physiol (1985) ; 64(4): 1584-90, 1988 Apr.
Article in English | MEDLINE | ID: mdl-3378994

ABSTRACT

It has been proposed that an increase in the affinity of hemoglobin for O2 may be beneficial in severe hypoxemia. To test this hypothesis, we compared the response to progressive hypoxemia in dogs with normal hemoglobin affinity (P50 = 32.4 +/- 0.7 Torr) to dogs with a left shift of the oxyhemoglobin dissociation curve (P50 = 21.9 +/- 0.5 Torr) induced by chronic oral administration of sodium cyanate. Animals were anesthetized, paralyzed, and mechanically ventilated. The inspired O2 fraction was progressively lowered by increasing the inspired fraction of N2. The lowest level of O2 transport required to maintain base-line O2 consumption (VO2) was 9.3 +/- 0.8 ml.min-1.kg-1 for control and 16.5 +/- 1.1 ml.min-1.kg-1 for the sodium cyanate-treated dogs (P less than 0.01). Other measured parameters at this level of O2 transport were, for experimental vs. control: arterial PO2 19.3 +/- 2.4 (SE) Torr vs. 21.8 +/- 1.6 Torr (NS); arterial O2 content 10.0 +/- 1.2 ml/dl vs. 4.9 +/- 0.4 ml/dl (P less than 0.01); mixed venous PO2 14.0 +/- 1.5 Torr vs. 13.8 +/- 1.0 Torr (NS); mixed venous O2 content 6.8 +/- 1.0 ml/dl vs. 2.3 +/- 0.2 ml/dl (P less than 0.01); and O2 extraction ratio 32.7 +/- 2.8% vs. 51.2 +/- 3.8% (P less than 0.01). We conclude that chronic administration of sodium cyanate appears to be detrimental to O2 transport, since the experimental dogs were unable to increase their O2 extraction ratios to the same level as control, thus requiring a higher level of O2 transport to maintain their base-line VO2 values.


Subject(s)
Cyanates/pharmacology , Oxygen Consumption/drug effects , Oxygen/blood , Oxyhemoglobins/metabolism , Animals , Dogs , Kinetics , Male , Reference Values
6.
Clin Sci (Lond) ; 74(2): 183-5, 1988 Feb.
Article in English | MEDLINE | ID: mdl-3276443

ABSTRACT

1. In healthy individuals, sleep is associated with a fall in urine and sodium output. 2. Seven male patients with obstructive sleep apnoea exhibited a paradoxical rise in both urine and sodium output during the hours of sleep. 3. Continuous positive airway pressure applied via the nose abolished both the apnoea and the nocturnal rise in urine and sodium output, thereby restoring the diurnal pattern towards normal.


Subject(s)
Circadian Rhythm , Sleep Apnea Syndromes/urine , Sodium/urine , Adult , Humans , Intermittent Positive-Pressure Ventilation , Male , Middle Aged , Sleep Apnea Syndromes/physiopathology , Sleep Apnea Syndromes/therapy
8.
Thorax ; 42(11): 892-6, 1987 Nov.
Article in English | MEDLINE | ID: mdl-3424271

ABSTRACT

Arterial oxygen saturation values (Sao2) from 60% to 98% were measured by the Ohmeda 3700 pulse oximeter with the three types of probe available and compared with values of oxygen saturation estimated from direct arterial sampling (arterial oxygen and carbon dioxide tensions and pH) on 65 occasions. The response time of the oximeter was measured after a sudden rise in inspired oxygen concentration. Artefact rejection was assessed by arterial compression proximal to the probe site, and by simultaneous recordings of overnight Sao2 on opposite hands. The ability to recreate patterns of oscillating Sao2 from the data stored in the oximeter was also investigated. With the best probe system the oximeter measured Sao2, relative to arterial values estimated from Pao2, with a mean (SD) difference of -0.4% (1.8%). The response time was comparable with those of previous oximeters. It was not possible to generate artefactual dips in excess of 2% Sao2, and the dual overnight recordings rarely showed even small dips on one tracing alone. The stored data can recreate oscillating Sao2 signals with wavelengths down to about 35 seconds, but not below. The Ohmeda 3700 pulse oximeter appears to be suitable for unattended overnight recordings of Sao2.


Subject(s)
Oximetry/instrumentation , Evaluation Studies as Topic , Humans , Oxygen/blood , Time Factors
9.
Br J Dis Chest ; 81(4): 349-55, 1987 Oct.
Article in English | MEDLINE | ID: mdl-3449121

ABSTRACT

A five-point dyspnoea scale (modified MRC questionnaire) and 12-minute walking test were used to compare the relationship between subjective assessment of dyspnoea and objective measurement of disability in patients with chronic airflow limitation, cardiac disease, and normal subjects. There was no overall difference in exercise performance between the cardiac and respiratory groups. There was a significant correlation between vital capacity and exercise performance, and the slope of the regression line was similar in the two groups. There was no correlation between vital capacity and exercise performance in the group of normal subjects. The five-point dyspnoea scale predicts similar levels of performance in the 12-minute walking test whether the dyspnoea is a result of cardiac or respiratory disease.


Subject(s)
Dyspnea/classification , Heart Diseases/complications , Lung Diseases, Obstructive/complications , Physical Exertion , Adult , Aged , Aged, 80 and over , Disability Evaluation , Dyspnea/etiology , Dyspnea/physiopathology , Forced Expiratory Volume , Heart Diseases/physiopathology , Humans , Lung Diseases, Obstructive/physiopathology , Middle Aged , Vital Capacity
10.
J Appl Physiol (1985) ; 60(3): 751-7, 1986 Mar.
Article in English | MEDLINE | ID: mdl-3957827

ABSTRACT

Hypothermia produces a decrease in metabolic rate that may be beneficial under conditions of reduced O2 delivery (Do2). Another effect of hypothermia is to increase the affinity of hemoglobin for O2, which can adversely affect the release of O2 to the tissues. To determine the overall effect of hypothermia on the ability of the peripheral tissues to extract O2 from blood, we compared the response to hypoxemia of hypothermic dogs (n = 8) and of normothermic controls (n = 8). The animals were anesthetized, mechanically ventilated, and paralyzed to prevent shivering. The inspired concentration of O2 was progressively reduced until the dogs died. The core temperatures of the control and hypothermic dogs were 37.7 +/- 0.3 and 30.5 +/- 0.1 degree C, respectively (P less than 0.01). The O2 consumption (VO2) of the control dogs was significantly greater than that of the hypothermic dogs (P less than 0.05), being 4.7 +/- 0.4 and 3.2 +/- 0.3 ml X min-1 X kg-1, respectively. Hypothermia produced a left shift of the oxyhemoglobin dissociation curve (ODC) to a PO2 at which hemoglobin is half-saturated with O2 of 19.8 +/- 0.7 Torr (control = 32.4 +/- 0.7 Torr, P less than 0.01). The O2 delivery at which the VO2 becomes supply dependent (DO2crit) was 8.5 ml X min-1 X kg-1 for control and 6.2 ml X min-1 X kg-1 for hypothermia. The hypothermic dogs maintained their base-line VO2's at lower arterial PO2's than control.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Hypothermia/metabolism , Oxygen Consumption , Oxygen/blood , Animals , Dogs , Hemodynamics , Hypothermia/blood , Hypothermia/physiopathology
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