Using complexity theory to build interventions that improve health care delivery in primary care

Previous observational research confirms abundant variation in primary care practice. While variation is sometimes viewed as problematic, its presence may also be highly informative in uncovering ways to enhance health care delivery when it represents unique adaptations to the values and needs of people within the practice and interactions with the local community and health care system. We describe a theoretical perspective for use in developing interventions to improve care that acknowledges the uniqueness of primary care practices and encourages flexibility in the form of intervention implementation, while maintaining fidelity to its essential functions.     

Increased (L+)-lactic acid production in lysozyme-inactivated suspensions of human dental plaque

The effect of lysozyme-inactivation on L(+)-lactic acid (LA) production in dental plaque suspensions was evaluated. From 10 children 24-h plaque was collected and lysozyme activity inhibited by addition of goat antiserum to human lysozyme. Acid production was stimulated by addition of glucose. The results showed significantly increased LA levels (50-150%) in lysozyme-inactivated plaque suspensions from 8 of the subjects compared to untreated controls. The increase in acid production activity was not related to plaque lysozyme levels. The findings indicate that the presence of lysozyme may be limiting on acid production in the early dental plaque.     

Does antenatal identification of small-for-gestational age fetuses significantly improve their outcome?

OBJECTIVES: Most obstetric clinics have a program for the identification of small-for-gestational age (SGA) fetuses because of the increased risk of fetal complications that they present. We have a structured model for the identification and follow-up of SGA pregnancies. We aimed to determine whether the recognition of SGA antepartum improves fetal outcome. METHODS: All pregnancies at Malm? University Hospital from 1990 to 1998 (n = 26 968) were reviewed. SGA fetuses identified prior to delivery (n = 681) were compared with those not identified (n = 573). Also, all pregnancies with SGA fetuses were compared with those appropriate-for-gestational age (AGA) (n = 24 585). The risk of serious fetal complications (hypoxic encephalopathy grade 2 or 3, intracranial hemorrhage, Apgar score <4 at 5 min, neonatal convulsions, umbilical pH <7.0, cerebral palsy, mental retardation, stillbirth, intrapartum or infant death) was assessed with cross-tabulation and logistic regression analysis, adjusted for gestational age and degree of SGA. RESULTS: When compared with SGA fetuses identified before delivery (54%), SGA fetuses not identified before delivery were characterized by a four-fold increased risk of adverse fetal outcome (odds ratio, 4.1; 95% CI, 2.5-6.8). Similarly, compared with AGA fetuses, SGA fetuses were associated with a four-fold increased risk of serious fetal complications. CONCLUSIONS: A structured antenatal surveillance program for fetuses identified as SGA results in a lower risk of adverse fetal outcome, compared with cases of SGA fetuses not identified antepartum.     

Mobile intraventricular cyst of the third ventricle treated with stereotactic puncture. Report of a case

A case of a pedunculated arachnoid cyst within the third ventricle is presented. The cyst was small so as not to appear as a significant expanding lesion on CT. The clinical history, however, suggested intermittent increase of the intracranial pressure. On CT there was some widening of the lateral and third ventricles, while the fourth ventricle had normal width. This finding in combination with the clinical history prompted further neuroradiologic examinations, including pneumoencephalography and ventriculography. The presence of a pedunculated mobile cystic lesion within the third ventricle was shown and its nature further elucidated by stereotactic puncture combined with contrast injection into the cyst. After emptying of the cyst, the patient has been free of symptoms during an observation time of 2 years. The diagnostic and differential diagnostic aspects are discussed and the value of traditional neuroradiologic methods emphasized.     

Effect of clavulanic acid, sulbactam and tazobactam on three different beta-lactamases from Bacteroides uniformis, Clostridium butyricum and Fusobacterium nucleatum.

The effect of three beta-lactamase inhibitors, clavulanic acid, sulbactam and tazobactam used in clinical practice were compared for their activity against purified beta-lactamases from Bacteroides uniformis, Clostridium butyricum and Fusobacterium nucleatum. The enzymes from B. uniformis and C. butyricum were produced in fermenters under controlled growth conditions and the enzyme from F. nucleatum was produced in batch cultures. Purification of the beta-lactamases was achieved by anion-exchange chromatography, gel filtration and FPLC-technique. The degree of inactivation of beta-lactamase activity was determined spectrophotometrically with nitrocefin as the substrate. The inhibitors in various concentrations were preincubated at 30 degrees C together with the enzyme for different time periods (0.5-120 min) before determination of the remaining beta-lactamase activity. The inhibitors all decreased the activity of the beta-lactamases investigated. Clavulanic acid and sulbactam were capable of reducing the enzyme activity of the B. uniformis beta-lactamase more effectively than the C. butyricum and F. nucleatum beta-lactamases. All beta-lactamases tested were more susceptible to tazobactam than to clavulanic acid and sulbactam.     

Extrapleural hematoma: emergency diagnostic pitfall. Value of computerized x-ray tomography]

A case of extrapleural haematoma consecutive to a chest injury is reported. This is a rare site of blood effusion since such injuries usually result in haemothorax. These two diagnosis can be distinguished not only by exploratory thoracotomy but also by computerized tomography which shows a characteristic subpleural fat-like ribbon.     

Rigid internal fixation of mandibular fractures. An analysis of 270 fractures treated using the AO/ASIF method.

The results are reported on 214 patients treated for 270 mandibular fractures, using rigid internal fixation. Of these, 172 fractures (63.7%) in 131 patients had been re-evaluated at final follow-up in connection with plate and screw removal, on average 15.2 months, postoperatively. Although one-third of the patients had a history of alcohol abuse, and 86% were treated with a delay of more than 24 h (mean 3.2 days), good primary bone healing was observed in 93.9% of the patients. Infections, seen in 6.1% of the patients, were related exclusively to inadequate stability of the fracture. Malocclusion, observed in 18.2% of 159 dentate patients, was caused by incorrect plate bending and insufficient fracture reduction. Immediate postoperative dysfunction of the inferior alveolar nerve in 58.1% of the cases, and of the mandibular branch of the facial nerve in 12.7%, was followed by almost total recovery 1 year after operation. It is concluded that rigid internal fixation is a reliable method of treatment, especially indicated for patients with reduced healing capacity and poor co-operation.