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At least 235 records · Page 13Linked to original sources
PubMed1995

Relation of spinal and thoracic cage deformities and their flexibilities with altered pulmonary functions in adolescent idiopathic scoliosis.

STUDY DESIGN: Seventy patients (average age, 13.8 years) with adolescent idiopathic right thoracic scoliosis had full assessment of pulmonary functions and radiographic evaluation of spinal and thoracic cage deformities and their flexibilities. OBJECTIVES: To determine how measurements of spinal and thoracic cage deformities related to pulmonary function. SUMMARY OF BACKGROUND DATA: Pulmonary functions have been evaluated in relation to lateral curvature of the spine in most of the published studies. Scoliosis is a three-dimensional deformity. There is a need to evaluate these changes in pulmonary functions, reflecting not only spinal curvature but also rotational deformity, thoracic cage deformity, and their flexibilities. METHODS: Radiographic measurements obtained from anteroposterior and lateral standing and anteroposterior supine bending radiographs included lateral curvature, vertebral rotation, kyphosis, maximum sternovertebral distance, and apical rib-vertebral angles. Using previous measurements, the flexibility of the curve, vertebral rotation, and rib-vertebral angle were calculated. A pulmonary function assessment was performed using a computerized pulmonary function system (5000V; Gould, Dayton, Ohio). We analyzed pulmonary functions in relation to deformity. RESULTS: Measurements reflecting spinal deformities obtained from anteroposterior radiographs, such as Cobb angle, vertebral rotation, and vertebral rotation flexibility, were significantly correlated with the percent of predicted values of vital capacity and forced vital capacity, whereas kyphosis measured from lateral radiographs was significantly correlated with absolute values of residual volume, total lung capacity, functional residual capacity, and forced expiratory flow from 25-75% of the forced vital capacity (FEF25-75). Of the measurements reflecting thoracic cage deformity obtained from anteroposterior radiographs, rib-vertebral angle asymmetry (measured from supine bending radiographs) showed significant correlation with the percent of predicted values of vital capacity, forced vital capacity, and functional residual capacity, whereas the sternovertebral distance that was measured from lateral radiographs correlated significantly with absolute values of vital capacity, total lung capacity, forced vital capacity, and FEF25-75. CONCLUSIONS: Deformities in coronal and transverse plane influence changes in pulmonary functions expressed as the percent of predicted values, whereas sagittal plane deformities influence mainly those absolute volumes in which residual volume is a component. It is suggested that rotational flexibility combined with other deformities could be evaluated in future studies on prediction of pulmonary function from the measurements of the deformity.

Adolescent↗
PubMed1979

[Oscillatory determination of functional residual capacity (FRC)].

The washing-in of a low density gas (80% He, 20% O2) into the lung is being eased by greater diffusibility and diminished work of breathing. Helium analysis was performed by means of the oscillation method with an equipment suitable for the assessment of resistance to breathing. The density of helium gas mixture is being compared to the density of ambient air.

Functional Residual Capacity↗
PubMed1987

Continuous positive airway pressure effect on functional residual capacity, vital capacity and its subdivisions.

Thirty-four otherwise healthy patients having to undergo elective upper abdominal surgery were randomly assigned to two equal groups. In the treatment group, constant positive airway pressure (CPAP) with an expiratory pressure of 12 cm H2O was applied at one hour following extubation, and at daily intervals for the first five days following surgery for a continuous period of three hours. The control group received no CPAP treatment. All patients were given postoperative physiotherapy. In patients who received postoperative CPAP with an end-expiratory pressure of 12 cm H2O, marked normalization of pulmonary function was noted.

Abdomen↗
PubMed1978

Functional residual capacity and body position in the dog.

Resting lung volumes in the supine position (FRCs) were determined by N2 washout method in 67 dogs under pentobarbital anesthesia and computed in ml/kg body weight (BW). In 21 other dogs, FRCs and the change in FRC from the supine to upright positions (deltaFRC) were determined; these lung volumes were expressed in ml/kg BW and in percentage of TLC40 (lung volume at 40 cmH2O positive-pressure inflation). It was found that a) FRCs averaged 38.6 plus or minus 8.2 and 42 plus or minus 5.9 ml/kg BW in the two groups of dogs; b) deltaFRC averaged 23 plus or minus 4 ml/kg BW resulted in large data dispersion, a large coefficient of variation (CV) and a poor correlation (r) of lung volume to BW; D) on the contrary, marked uniformity of FRCs and FRCu (upright FRC) was obtained by expressing the resting lung volumes in %TLC40, allowing an accurate prediction of FRC from the inspiratory capacity (IC). Relationship of FRCu to TLC was comparable to human data reported in the literature. FRCs (%TLC40) was smaller than values previously reported for awake human subjects, probably due to the FRCs reduction in our dogs by anesthesia.

Animals↗
PubMed1982

Measurement of functional residual capacity and pulmonary carbon monoxide diffusing capacity during mechanical ventilation with PEEP.

First, our new simplified method to measure FRC and DLCO simultaneously during mechanical ventilation was described in detail. Secondly, we applied the method to ARDS patients and observed the effects of PEEP on arterial blood gases (ABGs), FRC and DLCO of these patients. As reported hitherto, FRC was consistently increased by PEEP, whereas ABGs in some cases were not necessarily improved with increase in FRC. DLCO/FRC remained unchanged, although DLCO increased with PEEP. We concluded that the dissociation of FRC and ABG data in a group of patients could be caused by wasted ventilation which might be attributed to VA/Q unevenness.

Adult↗
PubMed1991

Perioperative functional residual capacity.

The literature dealing with the magnitude, mechanism and effects of reduced FRC in the perioperative period is reviewed. During general anaesthesia FRC is reduced by approximately 20%. The reduction is greater in the obese and in patients with COPD. The most likely mechanism is the loss of inspiratory muscle tone of the muscles acting on the rib cage. Gas trapping is an additional mechanism. Lung compliance decreases and airways resistance increases, in large part, due to decreased FRC. The larynx is displaced anteriorly and elongated, making laryngoscopy and intubation more difficult. The change in FRC creates or increases intrapulmonary shunt and areas of low ventilation to perfusion. This is due to the occurrence of compression atelectasis, and to regional changes in mechanics and airway closure which tend to reduce ventilation to dependent lung zones which are still well perfused. Abdominal and thoracic operations tend to increase shunting further. Large tidal volume but not PEEP will improve oxygenation, although both increase FRC. Both FRC and vital capacity are reduced following abdominal and thoracic surgery in a predictable pattern. The mechanism is the combined effect of incisional pain and reflex dysfunction of the diaphragm. Additional effects of thoracic surgery include pleural effusion, cooling of the phrenic nerve and mediastinal widening. Postoperative hypoxaemia is a function of reduced FRC and airway closure. There is no real difference among the various methods of active lung expansion in terms of the speed of restoration of lung function, or in preventing postoperative atelectasis/pneumonia. Epidural analgesia does not influence the rate of recovery of lung function, nor does it prevent atelectasis/pneumonia.

Anesthesia, General↗