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Biomedical subjects

N Powell

Publications and source records attributed to N Powell.

53 records · Page 3Linked to original sources
PubMed1985

Palatopharyngoplasty failure, cephalometric roentgenograms, and obstructive sleep apnea.

Nine patients with obstructive sleep apnea who underwent unsuccessful palatopharyngoplasty (PPP) as documented by polygraphic monitoring had abnormal cephalometric roentgenogram measurements. Findings indicated a small posterior airway space and inferiorly placed hyoid bone. Cephalometry performed with appropriate techniques to investigate soft tissue location should be obtained systematically in obstructive sleep apneic patients before any surgery is performed. The roentgenogram finding is a helpful guide in deciding whether PPP alone or PPP in combination with other surgical procedures would be more efficacious.

Adult↗
PubMed1985

Sleep apnea in normal subjects following mandibular osteotomy with retrusion.

Two women, 43 and 46 years old, weighing respectively 51 kg and 49 kg, underwent mandibular osteotomy with retrusion, after which they began to snore heavily at night. The initial events were central; obstructive apneic and hypopneic events, documented by polysomnography, developed over time. When patient 2 was on her back, she frequently had central apneas (identified by esophageal pressure monitoring) preceded by increasing swings in pressure, indicative of increased airway resistance without oxygen desaturation.

Adult↗
PubMed1984

Obstructive sleep apnea and abnormal cephalometric measurements. Implications for treatment.

The position of the hyoid bone, which anchors much of the tongue musculature, is often abnormally low in patients with obstructive sleep apnea syndrome (OSAS). Cephalometric measurements, frequently used to measure SNA and SNB angles, can also provide information on the posterior airway space (PAS), the mandibular plane, and the hyoid bone. This information is useful in determining the appropriate surgical treatment for OSAS patients.

Adult↗
PubMed1983

Cephalometric analyses and flow-volume loops in obstructive sleep apnea patients.

Fifteen patients with obstructive sleep apnea syndrome (OSAS) and 10 controls were studied. Polygraphic monitoring during sleep confirmed the presence or absence of OSAS. Ten OSAS patients and five controls had cephalometric analysis and 12 OSAS patients and five controls had a flow-volume loop study during wakefulness. Seven OSAS patients were submitted to both analyses. Flow-volume loops were unable to detect extrathoracic airway obstruction in six out of 12 OSAS patients. One control was found with positive results. Six out of seven subjects with positive flow-volume loops were overweight (greater than or equal to 30% ideal weight). Cephalograms were very useful in demonstrating mandibular deficiencies in OSAS patients. The length of the soft palate and the position of the hyoid bone, together with the measurement of the posterior airway space, are criteria of great interest in OSAS patients. Cephalometric analysis is recommended in all OSAS patients scheduled for surgical procedure. None of these tests, however, whether alone or in combination, is capable of identifying all cases of OSAS.

Adolescent↗
PubMed1976

131I Rose Bengal scanning and clearance ratios in the investigation of jaundiced patients.

It may be difficult to distinguish between obstructive and non-obstructive jaundice despite the use of clinical, biochemical and radiographic tests. Endoscopic cannulation tests promise to be the most accurate means of separating the two groups, but they are not yet widely available, and are not entirely safe. In contrast, the 131I-Rose Bengal test is simple, safe and comparatively widely available. Its accuracy in 70 jaundiced patients is reviewed to determine whether it still has a place in the investigation of jaundiced patients. Blood clearance traces, intestinal radioactivity traces and serial abdominal scans were done during a period of 3 h. The blood clearance ratios were not helpful discriminators, and the most helpful information was the timing of intestinal radioactivity. Its rapid appearance excluded mechanical obstruction. A delay of up to 3 h in its appearance was characteristic of cholestasis. A delay of more than 3 h was found in all cases of mechanical obstruction, but also in ten cases of severe cholestasis which could not be distinguished from those with mechanical obstruction. A follow-up examination within another ten days was of diagnostic value in two of these cases and the overall accuracy of the test was 86%. The potential value of prolonging the test to 24 h is discussed. It is concluded that the 131I-Rose Bengal test is a helpful diagnostic discriminator in the great majority of patients with jaundice. It is offered as a screening procedure for specialised techniques.

Biliary Tract Diseases↗
PubMed1975

Platelet 5-hydroxy-tryptamine in thrombotic and non-thrombotic diseases.

It is generally accepted that platelets from the main constituent of a thrombus. Experimental work has shown that 5-hydroxy-tryptamine (5 HT) in a concentration of 0.06 mg/ml produces clumping of the platelets. In view of this it was decided to estimate platelet 5 HT in thrombotic and non-thrombotic diseases. Thirty-five patients were investigated. Estimations of 5 HT were made on washed platelets rather than platelet-rich plasma which has been used in previous studies. Three groups were recognized on the basis of platelet 5 HT values. The first group consisted of five subjects who were clinically asymptomatic at the time of investigation but died 24 to 48 hours later and were shown at autopsy to have deep-vein thrombosis and pulmonary embolism; they had the highest level of platelet 5 HT. The second group comprised eight patients with cerebral thrombosis whose platelet 5 HT ranged between 1529 and 2183 ng/10-9. There were 22 subjects in the third group (11 apparently normal and 11 with different pathologies). Their platelet 5 HT ranged from 611 to 877 ng/10-9 and did not vary in the different pathological conditions studied. Since the highest level of platelet 5 HT was observed in patients prior to the formation or embolization of a thrombus, it is suggested that this may have some role in initiating thrombus formation.

Age Factors↗
PubMed1974

Assessment of potassium metabolism, using 42K, in cases of myxoedema before and after treatment with thyroxine.

Total Exchangeable Potassium (TEK) was measured in 31 elderly patients admitted to a geriatric assessment unit. The value in control cases ranged between 26 mEq/kg to 45.5 mEq/kg; the mean values for men and women were 35.5 mEq/kg and 28.4 mEq/kg, respectively. The test was repeated after one week in eight cases, the standard deviation between the two estimations ranged from 0.35 to 1.13 with the exception of one case which was 2.55. Estimations were made in six cases of myxoedema, the initial value was low and on treatment rose by 22.6 per cent to 36.4 per cent which coincided with the clinical improvement.

Age Factors↗
PubMed1971

Australia antigen and liver function tests following infectious hepatitis. A study of 111 patients in quest of aids in blood donor screening.

An epidemic of infectious hepatitis involving 99 patients and employees of a state mental hospital revealed Australia antigen Au(1) to be absent from the blood of all but one of the subjects when tested at six weeks, three months, nine months and 12 to 18 months after onset of jaundice. The single patient with Au(1) at 12 months had no enzyme abnormality to indicate residual liver disease. If Au(1) is the virus of hepatitis these data would support the concept that persistent or long standing viremia is not a feature of epidemic hepatitis. Moreover, results of this study suggest that the Au(1) test should not be used to establish the absence of a past history of hepatitis in blood donors. These data do not establish the value of the Au(1) test in blood donors with active viremia, but do suggest that of 111 patients with recent hepatitis 1 percent had persistent antigenemia and 4 percent probably had circulating antigen antibody complexes and constituted a potential risk to recipients of their blood. The degree of risk to recipients from transfused blood of post-hepatitis patients without demonstrable Au(1) cannot be assessed.

Blood Donors↗
PubMedDate not supplied

Ultrasound and neonatal hip screening: the five-year results of a prospective study in high-risk babies.

We present the 5-year results of an ongoing prospective study of static ultrasound scanning for developmental dysplasia of the hip (DDH) to enlarge on and update the findings after the first year of this screening programme. Between January 1988 and December 1992, there were 17,792 births, 2,683 of which had risk factors: 354 babies had abnormal scans. Screening failed in eight cases, two of which were preventable because they had risk factors but were not scanned; however, six cases came from the 85% of babies without risk factors. The incidence of late cases is therefore 0.45 per thousand births. These results indicate that static ultrasound scanning is effective in detecting abnormal hips, but if only the "at risk" group is screened in this way, then there will be an expected rate of late cases of approximately 0.34/1,000. We are concerned with the results of screening (i.e., detection) but not management. We conclude that simple static ultrasound is an effective screening test for DDH but that it should be applied to the whole population and not simply to the "at risk" group.

Cohort Studies↗
PubMedDate not supplied

Physiotherapy in Mount Hagen General Hospital: an audit of activity over a six-month period.

There is a lack of a sustainable physiotherapy service in most hospitals in Papua New Guinea. Many clinicians, managers and senior administrators appear unaware of the benefits that such a service can provide. This survey uses an audit tool, a modified Körner form, to evaluate the impact of a physiotherapy service within a provincial hospital during a six-month period. The audit measures number of patients seen, types of diagnosis, time spent with individual patients and number of treatment sessions provided. 571 patients were seen in the 6 months, of whom 308 were outpatients and 263 were inpatients. Inpatients received an average of 3 hours of treatment per patient, outpatients received 1 hour. Most patients seen were those who suffer disability as a result of their condition and who would traditionally have a poor prognosis without physiotherapy intervention. The most common conditions seen were neurological disability in adults and children, conditions requiring orthopaedic rehabilitation, burns, arthritic conditions and those requiring respiratory physiotherapy techniques. The physiotherapy department at the hospital was the only establishment in the district able to provide a rehabilitation service for these patients. Hence physiotherapy greatly improved the services available to the most sick and disabled patients within the community. The fact that outpatient follow-ups proved problematic for so many patients suggests that patients should be kept in hospital until their rehabilitation needs have been fully met.

Adolescent↗
PubMedDate not supplied

Mandibular advancement and obstructive sleep apnea syndrome.

A surgical procedure performed to advance the mandible in patients with retrognathia and obstructive sleep apnea is described. The case history of an obese patient with severe sleep apnea problems who underwent a number of treatments, responding only to mandibular advancement, is presented.

Adult↗