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Biomedical subjects

B Karlsen

Publications and source records attributed to B Karlsen.

9 recordsLinked to original sources
PubMed2004

EEG background activity described by a large computerized database.

OBJECTIVE: To show how our newly developed software for classification and storage of visually routinely assessed EEGs are used to evaluate the general background activity (GBA) and the alpha rhythm (AR) in a large number of prospective EEGs. METHODS: EEGs from 4651 consecutive patients were visually assessed using a computerized description system connected to an EEG database. The AR and the GBA apart from the AR were described separately for frequency and amplitude. RESULTS: AR frequencies declined from the age of 45 years and slowed with increasing age independently of non-AR pathology and gender. Females had higher AR frequencies than males. EEGs with non-GBA pathology had lower GBA frequencies and higher GBA amplitudes. Higher GBA amplitudes were associated with lower GBA frequencies in normal EEGs for all age groups. EEG interpretations by 4 independent electroencephalographers showed the same trends, but differed in exact assessment of frequencies and amplitudes. CONCLUSIONS: EEG interpretations stored in a categorized database with easy access to data have successfully been used to evaluate interobserver variation and other quality control measurements. Statistical analysis of the data has at the same time produced new information regarding the development of AR and GBA throughout life.

Adolescent↗
PubMed2002

In-line versus pistol-grip handles in a laparoscopic simulators. A randomized controlled crossover trial.

BACKGROUND: Needleholders with in-line handles (ILH) and those with pistol-grip handles (PGH) were compared in terms of operative end-product quality (OEPQ), procedure effectiveness (PE), and surgeon forearm workload (SFWL) during suturing in a laparoscopic simulator. METHODS: A 90% power crossover design at alpha 0.05 required 46 surgeons. Block randomization generated ILH-PGH or PGH-ILH sequence allocation. The task involved suturing a perforated ulcer on a foam stomach in a simulator. In this study, OEPQ was measured by tissue damage, accuracy error, water leak; PE by operating time and motion analysis including goal-directed actions (GDA) and non-goal-directed actions (NGDA); and SFWL by electromyogram (EMG) of six forearm and thumb muscles. RESULTS: The 46 surgeons performed the tasks as allocated. All the variables but two were significantly different between the first and second tasks, ignoring the handle type. There was no evidence of an unequal carryover effect when the comparison was stratified by ILH-PGH or PGH-ILH sequence. As compared with ILH, PGH tissue damage (0.1 vs 0.2 mm; p = 0.06) and NGDA (1 vs 1 p = 0.09) were different, whereas accuracy error, leak rates, operating time, GDA, and EMG were not. CONCLUSIONS: As compared with ILH needleholders, the use of PGH needleholders led to increased tissue damage and non-goal-directed actions during a suturing task in a simulator.

Computer Simulation↗
PubMed2001

[Neuromuscular complications of sepsis].

BACKGROUND: Neuromuscular complications are common in patients treated for sepsis and multiple organ dysfunction in critical care units. Failure to wean from the ventilator, due to involvement of the respiratory system, and severe muscular weakness are typical symptoms. Electrophysiological examination demonstrates fibrillation potentials and reduction of compound muscular action potential amplitudes. MATERIAL AND METHODS: We report three patients with severe muscular weakness during treatment of critical illness. RESULTS: Critical illness polyneuropathy was the main cause of weakness in two patients, with a presumed superimposed myopathy in one. A third patient had critical illness myopathy. INTERPRETATION: Critical illness polyneuropathy and myopathy--either as separate or combined entities--are common causes of muscular weakness during treatment of critical illness. These disorders are often difficult to distinguish from each other, as the clinical and electrophysiological findings may overlap. Sepsis and multiple organ dysfunction are the main aetiological factors, but certain drugs may contribute in the pathogenesis. No specific treatment exists. In the most severe cases long-lasting physiotherapy and rehabilitation is needed.

Aged↗
PubMed2000

[Non-convulsive status epilepticus--confusion and cognitive failure during seizures].

BACKGROUND: Non-convulsive status epilepticus is characterized by confusion and impaired consciousness, lasting at least half an hour. Seizure activity in the EEG confirms the diagnosis, but ictal discharges can be heterogeneous and difficult to classify. There is controversy regarding evidence of morbidity in humans. MATERIAL AND METHODS: We report three patients with non-convulsive status epilepticus. RESULTS: In two patients, the clinical findings during seizures were subtle cognitive impairment. One patient was confused during seizures. Localisation of seizure activity in the EEG was mainly frontal in two patients, and generalised with focal predominance in one. There were no sign of neurologic sequelae after the seizures were terminated. INTERPRETATION: Complex partial status epilepticus of frontal origin is common, but differentiation between complex partial and generalised non-convulsive status can be difficult. The clinical symptoms may overlap, and generalised EEG seizure activity does not exclude initial focal ictal discharges. Presumably the reported sequelae after this condition are in most cases a consequence of underlying cerebral illness. Treatment response to diazepam can be variable, with high recurrence risk. Effective prophylactic treatment is most important.

Adult↗
PubMed1999

A new way of building a database of EEG findings.

Whereas computer-based electroencephalography (EEG) is widely applied, the EEG interpretations are usually not stored in a way that favours exploitation of modern computer technology. This paper reports an EEG description system facilitating categorization of EEG data in a computerized database. The system interactively communicates with the digital EEG system and also with the general patient administrative system. The main new quality of this system is the methods for data input and automatic data retrieval from several systems, rather than the establishment of a database of EEG data itself. The EEGs are visually analysed and categorized. Manually marked EEG events are automatically transferred to the database and such events as well as defined electrode positions within these epochs are directly linked to their corresponding descriptions. The database is updated without demand for filling in the events in the database in a second operation. Thereby, the EEG interpreter builds the database while analysing the EEG. This system provides an improved accessibility of EEG data for clinical, normative, educational and scientific use.

Brain↗
PubMed1997

Hospital nurses' perceptions of patient teaching.

Patient teaching in general hospitals is becoming increasingly important both due to higher patient turnover and the principles of self-care. This study focuses on how hospital nurses describe ideals and realities in teaching adult patients in a general hospital, and how they describe the factors affecting their teaching function. The study has a qualitative approach. Fourteen registered nurses, working in a general hospital, are interviewed. The interviews are semistructured. The four stages adapted from Glaser & Strauss' grounded theory approach are used as a support in the elaboration and the analysis of the data. The study shows that the ideals about patient teaching are rather weakly articulated. The realities are, however, more distinctly described. Empirical findings reveal two different 'teaching processes' articulated by the informants. Both processes are novel and different from the traditional teaching process mentioned in the literature. Which processes the nurses are applying in the clinic seem to depend on the objective and content of the patient teaching. This evidence has so far not been reported in previous studies. Regarding the factors affecting their patient teaching, the nurses emphasize the following three; The nurses' qualifications, training in the teaching function and the organizational setting.

Adult↗
PubMed1996

[Guillain-Barré syndrome. Variation on the theme].

Guillain-Barré syndrome, or acute inflammatory demyelinating polyneuropathy, is a frequent cause of acute onset of flaccid paresis and areflexia. Electrophysiological studies show demyelination, sometimes with varying degrees of axonal degeneration. In some cases axonal degeneration apparently develops rapidly, without signs of primary demyelination. However, it is still a matter of discussion whether a pure axonal form of Guillain-Barré syndrome exists, or whether the axonal degeneration is secondary to demyelination. We report on clinical and electrophysiological findings in three patients with variants of Guillain-Barré syndrome. These include pure demyelination, combined demyelination and axonal degeneration and possible primary axonal degeneration. Electrophysiological studies can differentiate between the variants of Guillain-Barré syndrome, and thus give indications of pathogenesis and prognosis.

Adult↗