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K Rees

Publications and source records attributed to K Rees.

30 records · Page 2Linked to original sources
PubMed1995

Systemic arterial blood pressure during obstructive sleep apnoea.

The cardiovascular changes that accompany obstructive apnoeic events are now well recognized, but their relationship to other processes during the apnoea, whether mechanical, chemical or neurophysiological remains unclear. These relationships have been examined by focusing on arterial blood pressure measured non-invasively using the Finapres device, gas tensions (SaO2, ETCO2), intrathoracic effort (Ppl) and the median EEG frequency (derived from off-line FFT analysis). Eighteen patients with OSA were studied (mean age 43.7 y, BMI 31.2, A + HI 41.2) during stable NREM sleep. However, not all variables were measured for each patient. Data were analysed for the breath before, at the start, mid and end of the apnoea and immediately afterwards. Mean blood pressure initially fell with the onset of apnoea, remained stable until mid-apnoea but rose acutely with apnoea termination. The mean systolic and diastolic pressures were greater during inspiration for the initial and mid-apnoeic efforts, but this difference was reversed at apnoea termination, possibly reflecting the onset of the arousal response. The change in blood pressure over the apnoea was unrelated to apnoea duration and only weakly associated with the intensity of the peak pleural pressure. The rise in blood pressure at end apnoea was related to the fall in SaO2, but not to changes in ETCO2. There was no correlation between the change in EEG frequency and blood pressure over the apnoea as a whole but the increase in blood pressure from the final effort to the first breath correlated with the change in EEG frequency. These data suggest that the change in arterial pressure during an obstructive apnoea are only weakly dependent on the intensity of inspiratory effort made, but are modified by chemical factors and especially changes in sleep state. The close relationship between arousal and change in blood pressure in NREM events confirms the usefulness of cardiovascular markers of arousal responses in OSA.

Journal Article↗
PubMed1995

Arousal responses from apneic events during non-rapid-eye-movement sleep.

Patients with obstructive sleep apnea (OSA) experience severe sleep disruption and consequent daytime sleepiness. Current arousal scoring criteria show that some obstructive apneic events do not end in a recognizable cortical electroencephalographic (EEG) arousal. It is not known whether events that end in an obvious EEG arousal differ from those that do not, in terms of EEG frequency changes during the apneic event, the respiratory effort developed prior to apnea termination, the degree of the postapneic increase in blood pressure, or changes in CO2 tensions. We studied 15 patients with OSA in early Stage 2 sleep and analyzed obstructive apneic events with and without typical EEG arousals, defining an arousal as a frequency shift to waking alpha rhythm of 1 s or longer. EEG signals were digitized and analyzed by fast Fourier transform during and immediately after each apnea. The median EEG frequency and mean pleural pressure of the first and second halves of the apneic episode were compared with that of the first breath. Peak pleural pressure was measured just before the end of the apneic episode. Systolic and diastolic blood pressures and CO2 tensions were measured at the onset and termination of apnea. For each patient, 10 events that ended in EEG arousal were compared with 10 events that did not. Mean apnea duration did not differ for the two groups of events. Median EEG frequency and pleural pressure increased significantly from 8.14 to 9.25 Hz and 15.4 to 22.1 cm H2O, respectively, as the apnea progressed, but there was no difference between the groups nor any difference in the peak pleural pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Does cold air affect exercise capacity and dyspnea in stable chronic obstructive pulmonary disease?

Cold air may worsen asthmatic bronchoconstriction but can lessen breathlessness in normal individuals. Patients with COPD sometimes report improvement in their dyspnea in cold weather. We examined the effect of breathing cold air on exercise tolerance and the perception of breathlessness in 19 patients with stable COPD (age [+/- SD], 63 +/- 6 years; FEV1, 0.99 +/- 0.28 L) in a randomized open study. Patients exercised on a cycle ergometer breathing either room or cold air (-13 degrees C), breathlessness being assessed by Borg scaling. Peak exercise performance improved when breathing cold air (mean +/- SE), 46 +/- 6 W compared with 37 +/- 7 W (p < 0.05) while end-exercise breathlessness fell from 4.6 +/- 0.4 compared with 4.1 +/- 0.5 (p < 0.05) when breathing cold air. End-exercise ETCO2 was higher breathing cold air (6.1 +/- 0.3 kPa compared with 5.5 +/- 0.3 kPa) (p < 0.005). There was no difference in breathlessness at equivalent levels of ventilation. Cold air reduces breathlessness in COPD, probably by inducing relative hypoventilation.

Aged↗
PubMed1987

"I want to be a daddy!": meanings of masculine identifications in girls.

This paper suggests revisions in our understanding of feminine identity formation, the girl's negative oedipus complex, and masculine identifications in girls. Analytic material from the cases of three girls is used to explore the various origins and intrapsychic functions of masculine identifications at each phase of the girl's development. Accounts of feminine development based on such concepts as castration shock, primary femininity, primary identification with mother, or core gender identity are seen as oversimplified. Feminine and masculine identifications are neither primary nor secondary, but the product of a long line of development, of ongoing conflict resolution, and of defensive transformations.

Child↗
PubMedDate not supplied

The somnogenic T lymphocyte suppressor prostaglandin D2 is selectively elevated in cerebrospinal fluid of advanced sleeping sickness patients.

To help to elucidate the changes induced by Trypanosoma brucei gambiense in the central nervous system (CNS) in advanced sleeping sickness patients, levels of interleukin-1 (IL-1) and prostaglandins D2 (PGD2) and E2 (PGE2) were measured by radioimmunoassay in the cerebrospinal fluid (CSF) from 24 patients diagnosed on the criteria of CSF protein, leucocyte count and parasite presence as having CNS (i.e. late stage) involvement, and from 12 patients without CNS involvement. PGD2 concentrations were selectively and markedly elevated in the late stage patients. The increased PGD2 may in part account for the increased somnolence and the immunosuppression within the CNS. Measurement of PGD2 levels in CSF may be a useful criterion for CNS involvement.

Adolescent↗
PubMedDate not supplied

Caring for people who are dying on renal wards: a retrospective study.

Unfortunately, there is still a high mortality rate among patients with end-stage renal disease (ESRD). If the decision is made to activate non-dialytic management of the patient with ESRD, it should be made jointly by the patient and responsible consultant nephrologist after consultation with relatives, the family doctor and other relevant members of the caring team. This paper discusses the establishment of a new renal supportive care service for patients opting not to have dialysis and focuses on the results of a 'death audit' carried out on this patient population. Recommendations for practice resulting from analysis of the audit results include, the use of advance directives, identification and prompt treatment of symptoms, increased staff education, timely referral to the palliative care team and expansion and further integration of the renal supportive care team.

Adult↗