Nocturnal haemoglobin oxygen saturation variability is associated with vitamin C deficiency in Tanzanian children with sickle cell anaemia.

AIM: To compare pulse oximetry in children with sickle cell anaemia (SCA) and controls and test the hypothesis that vitamin C deficiency (VCD; <11.4 µmol/L) is associated with nocturnal haemoglobin oxygen desaturation in SCA. METHODS: We undertook nocturnal and daytime pulse oximetry in 23 children with SCA (median age 8 years) with known steady-state plasma vitamin C concentrations and 18 siblings (median 7 years). RESULTS: Median nocturnal delta 12 s index (delta12 s), a measure of haemoglobin oxygen saturation (SpO(2)) variability, was 0.38 (interquartile range 0.28-0.51) in SCA and 0.35 (0.23-0.48) in controls, with 9/23 and 6/18, respectively, having a delta12 s >0.4, compatible with obstructive sleep apnoea (OSA). Eleven of twenty-three with SCA had VCD; logged vitamin C concentrations showed a 66% decrease per 0.1 unit increase in delta12 s ([95% CI -86%, -15%]; p=0.023) and delta12 s >0.4 was associated with VCD (odds ratio 8.75 [1.24-61.7], p=0.029). Daytime and mean nocturnal SpO(2) were lower in SCA but there was no association with vitamin C. CONCLUSION: Obstructive sleep apnoea (OSA), detected from nocturnal haemoglobin oxygen saturation variability, is common in Tanzanian children and associated with vitamin C Deficiency in SCA. The direction of causality could be determined by comparing OSA treatment with vitamin C supplementation.

Nerve morbidity following wisdom tooth removal under local and general anaesthesia.

Two hundred and one patients had unilateral removal of the lower third molars under local anaesthesia and a further 234 patients had either bilateral or unilateral removal under general anaesthesia. A total of 634 lower third molars were extracted by four experienced surgeons (two consultants and two senior grade staff). All patients were reviewed independently 1-week postoperatively and any sensory disturbance and its location was recorded. Patients with sensory disturbance were subsequently reviewed at 1 month and again at 6 months if recovery was not complete. This study demonstrated little difference in the adverse event rate per tooth extracted between procedures under local and general anaesthesia. However, within the general anaesthetic group, the few unilateral procedures showed evidence of higher risk, but the number was too small for valid satisfactory analysis. The risk of nerve morbidity was also greater where the duration of the procedure was longer than 15 minutes in unilateral cases.

Salivary cortisol determinations and self-rating scales in the assessment of stress in patients undergoing the extraction of wisdom teeth.

OBJECTIVE: To investigate salivary cortisol levels in patients undergoing third molar removal under local and general anaesthesia. DESIGN: Random sampling of two independent groups. METHODS: Samples of saliva were collected from patients prior to and after surgery for the removal of impacted wisdom teeth. The samples were analysed to assess cortisol levels. Patients were also asked to complete a Hospital Anxiety and Depression questionnaire on the day of surgery. RESULTS: Patients receiving treatment under local anaesthesia showed lower levels of stress response than those having treatment under general anaesthesia on the actual day of surgery did (Fig. 1). No other significant differences were noted. CONCLUSION: Local anaesthesia is the preferred mode of pain control for patients who express no strong preference for type of anaesthetic.

Pregabalin in patients with postoperative dental pain.

Pregabalin is an analogue of the inhibitory neurotransmitter gamma-aminobutyric acid. In preclinical models, it has shown activity as an analgesic agent. A randomized, double-blind, placebo-controlled, parallel-group trial was undertaken to compare pregabalin to placebo and 400 mg of ibuprofen using a dental pain model. Study medication was administered postoperatively to patients who had undergone elective surgery to remove one or two third molars, at least one of which was mandibular and fully or partially impacted in bone. The study was conducted in the UK at a single centre and evaluated pregabalin at doses of 50 and 300 mg. Primary efficacy parameters included pain relief (PR), pain intensity difference (PID), pain relief intensity difference (PRID), time to onset of analgesia, and duration of analgesia. The patient's global impression of the study medication was used as a secondary efficacy parameter. Efficacy data were evaluated for the intent-to-treat (ITT) population, defined as all randomized patients who took study medication. Results showed that there were statistically significant differences in PR, PID, and PRID between the 300-mg pregabalin group and placebo. In addition, the 300-mg pregabalin group had a significantly longer duration of analgesia than the ibuprofen group and had the highest score on the patient global impression of study medication. Adverse events were reported more frequently in the pregabalin 300-mg group. Pregabalin appears to have significant analgesic properties in the third molar extraction model. Further research is needed to confirm these findings.

GnRH antagonist inhibition of luteinizing hormone secretion and ovulation in the pig.

A GnRH antagonist, Ac-D-p-Cl-Phe1,2, D-Trp3, D-Arg6, D-Ala10 GnRHb (Organon), was utilized to determine the effective dosage and duration to inhibit LH secretion in the pig. In a preliminary trial, barrows received either 10, 50, or 250 micrograms/kg BW of the GnRH antagonist. Secretion of LH was inhibited within 30 min for a duration of 12 h with the 100 micrograms/kg dose but persisted for greater than 48 h with the 250 micrograms/kg treatment. A second study determined effectiveness of the antagonist for inhibiting ovulation in cyclic gilts. At first detection of standing estrus, cyclic gilts were treated with either saline (control), 100, or 200 micrograms/kg BW of the GnRH antagonist (GnRH1). A second group of GnRH antagonist gilts received 200 micrograms/kg BW of the GnRH antagonist approximately 8 h prior to standing estrus (GnRH2). The GnRH1-treatment failed to inhibit or delay ovulation. Ovulation was inhibited and estrous cycles lengthened in GnRH2-treated gilts. These preliminary results suggest that ovulation in the gilt can be inhibited if the GnRH antagonist is administered prior to the LH surge.

Plasma lipid concentrations in children with cystic fibrosis: the value of a high-fat diet and pancreatic supplementation.

Impaired digestion of dietary fat is an almost universal feature of cystic fibrosis (CF) which results in low concentrations of essential fatty acids in plasma lipids. We have evaluated the effect of a high-lipid diet and pancreatic enzyme supplementation, using enteric-coated microsphere preparations, on plasma lipid concentrations in paediatric CF patients. Absorption of dietary lipid was comparable between control and CF subjects. This resulted in plasma cholesterol, triacylglycerol, total phosphatidylcholine and individual phosphatidylcholine molecular species concentrations in CF patients which were in the same range as those in controls. Normal values for these variables were also found in patients with clinically detectable liver disease. These results show that present dietary management of CF patients supports normal plasma lipid concentrations.