Effects of Rapid Palatal Expansion on Chewing Biomechanics in Children with Malocclusion: A Surface Electromyography Study.

Malocclusion during childhood may affect both morphology and masticatory function and could greatly affect the subsequent growth and development of the jaws and face. The purpose of this study was to evaluate the efficiency of surface electromyography in describing the effects of the rapid palatal expansion (RPE) on Masseter (M) and Temporalis Anterior (T) muscles' activity in 53 children with different types of malocclusion: bilateral posterior crossbite (BPcb), underdeveloped maxillary complex without crossbite (NOcb) and unilateral posterior crossbite on the right (UPCBr) and on the left (UPCBl). The muscular activities during chewing tasks were assessed bilaterally before and after RPE application and three months after removal. Both the envelope's peak (µV) and its occurrence (% of chewing task) were extracted from the surface electromyography signal. Our results showed the presence of statistically significant differences (p < 0.05) on temporomandibular joint muscles, across different assessments, in all the tested populations of subjects. Surface electromyography demonstrated a relationship between the correction of a maxillary transverse discrepancy and the restoration of a muscle's activation patterns comparable to healthy subjects for both T and M.

Usefulness of the STOP-Bang Questionnaire in a Cardiac Surgical Population.

OBJECTIVE: The aim of this study was to assess the predictive accuracy of the STOP-Bang questionnaire in relation to obstructive sleep apnea (OSA) detected by nocturnal oximetry, as well as postoperative outcomes, in a population undergoing cardiac surgery. DESIGN: A prospective observational cohort study. SETTING: The specialist cardiothoracic center at the Royal Papworth Hospital, Cambridge University Health Partners, United Kingdom. PARTICIPANTS: All adult patients, undergoing elective coronary artery bypass grafting with or without cardiac valve surgery between March 2013 and July 2014 were included. The authors excluded patients participating in other interventional studies, those who had a tracheostomy before surgery, and those who required emergency surgery or were due to be admitted on the day of surgery. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Cardiac surgical patients were screened for the risk of OSA with the use of STOP-Bang questionnaire. The presence of OSA prior to surgery was assessed with overnight oximetry. The predictive performance of the STOP-Bang questionnaire was assessed by calculating sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve (AUC)-receiver operating characteristic curve (ROC). Multiple-logistic regression models were used to assess for associations between the STOP-Bang scores and postoperative outcomes. The STOP-Bang questionnaire discriminated poorly between mild OSA (AUC-ROC 0.57 [95% confidence interval (CI) 0.47-0.67]) and moderate/severe OSA (AUC-ROC 0.82 (95% CI 0.69-0.95)]. Accuracy was increased by modifying the cut-off value to 6 or greater, with sensitivity and specificity of 75% and 77%, respectively. A STOP-Bang score indicating the possibility of OSA was not significantly associated with prolonged intensive care unit lengths of stay (hazard ratio [HR] 1.1; 95% CI 0.99-1.19; p = 0.08) or postoperative complications (odds ratio [OR] 1.0; 95% CI 0.59-1.72; p = 0.98). CONCLUSIONS: In the study population, a STOP-Bang questionnaire score of 3 or greater had limited predictive value for identifying cardiac surgical patients at high risk of OSA. STOP-Bang scores were not significantly associated with worse postoperative outcomes. A STOP-Bang score of 6 or greater could help identify patients in need of a sleep study to confirm the presence of OSA as such patients may be at increased risk of postoperative complications.

Effects of opioid, hypnotic and sedating medications on sleep-disordered breathing in adults with obstructive sleep apnoea.

BACKGROUND: Obstructive sleep apnoea (OSA) is a common sleep disorder characterised by partial or complete upper airway occlusion during sleep, leading to intermittent cessation (apnoea) or reduction (hypopnoea) of airflow and dips in arterial oxygen saturation during sleep. Many patients with recognised and unrecognised OSA receive hypnotics, sedatives and opiates/opioids to treat conditions including pain, anxiety and difficulty sleeping. Concerns have been expressed that administration of these drugs to people with co-existing OSA may worsen OSA. OBJECTIVES: To investigate whether administration of sedative and hypnotic drugs exacerbates the severity of OSA (as measured by the apnoea-hypopnoea index (AHI) or the 4% oxygen desaturation index (ODI)) in people with known OSA. SEARCH METHODS: We searched the Cochrane Airways Group Specialised Register (CAGR) of trials. The search was current as of March 2015. SELECTION CRITERIA: Randomised, placebo-controlled trials including adult participants with confirmed OSA, where participants were randomly assigned to use opiates or opioids, sedatives, hypnotics or placebo. We included participants already using continuous positive airway pressure (CPAP) or a mandibular advancement device. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures as recommended by The Cochrane Collaboration. MAIN RESULTS: Fourteen studies examining the effects of 10 drugs and including a total of 293 participants contributed to this review. Trials were small, with only two trials, which used sodium oxybate, recruiting more than 40 participants, and all but three trials were of only one to three nights in duration. Most participants had mild to moderate OSA with a mean AHI of 11 to 25 events/h, and only two trials recruited patients with severe OSA. Two trials investigating the effects of ramelteon, a treatment option for insomnia, recruited adults over 60 years of age with OSA and concomitant insomnia.The drugs studied in this review included remifentanil (infusion) 0.75 mcg/kg/h, eszopiclone 3 mg, zolpidem 10 and 20 mg, brotizolam 0.25 mg, flurazepam 30 mg, nitrazepam 10 mg to 15 mg, temazepam 10 mg, triazolam 0.25 mg, ramelteon 8 mg and 16 mg and sodium oxybate 4.5 g and 9 g. We were unable to pool most of the data, with the exception of data for eszopiclone and ramelteon.None of the drugs in this review produced a significant increase in AHI or ODI. Two trials have shown a beneficial effect on OSA. One study showed that a single administration of eszopiclone 3 mg significantly decreased AHI compared with placebo (24 ± 4 vs 31 ± 5; P value < 0.05), and a second study of sodium oxybate 4.5 g showed a significant decrease in AHI compared with placebo (mean difference (MD) -7.41, 95% confidence interval (CI) -14.17 to -0.65; N = 48).Only four trials reported outcome data on ODI. No significant increase, in comparison with placebo, was shown with eszopiclone (21 (22 to 37) vs 28.0 (15 to 36); P value = NS), zolpidem (0.81 ± 0.29 vs 1.46 ± 0.53; P value = NS), flurazepam (18.6 ± 19 vs 19.6 ± 15.9; P value = NS) and temazepam (6.53 ± 9.4 vs 6.56 ± 8.3; P value = 0.98).A significant decrease in minimum nocturnal peripheral capillary oxygen saturation (SpO2) was observed with zolpidem 20 mg (76.8 vs 85.2; P value = 0.002), flurazepam 30 mg (81.7 vs 85.2; P value = 0.002), remifentanil infusion (MD -7.00, 95% CI -11.95 to -2.05) and triazolam 0.25 mg in both rapid eye movement (REM) and non-REM (NREM) sleep (MD -14.00, 95% CI -21.84 to -6.16; MD -10.20, 95% CI -16.08 to -4.32, respectively.One study investigated the effect of an opiate (remifentanil) on patients with moderate OSA. Remifentanil infusion did not significantly change AHI (MD 10.00, 95% CI -9.83 to 29.83); however it did significantly decrease the number of obstructive apnoeas (MD -9.00, 95% CI -17.40 to -0.60) and significantly increased the number of central apnoeas (MD 16.00, 95% CI -2.21 to 34.21). Similarly, although without significant effect on obstructive apnoeas, central apnoeas were increased in the sodium oxybate 9 g treatment group (MD 7.3 (18); P value = 0.005) in a cross-over trial.Drugs studied in this review were generally well tolerated, apart from adverse events reported in 19 study participants prescribed remifentanil (n = 1), eszopiclone (n = 6), sodium oxybate (n = 9) or ramelteon (n = 3). AUTHORS' CONCLUSIONS: The findings of this review show that currently no evidence suggests that the pharmacological compounds assessed have a deleterious effect on the severity of OSA as measured by change in AHI or ODI. Significant clinical and statistical decreases in minimum overnight SpO2 were observed with remifentanil, zolpidem 20 mg and triazolam 0.25 mg. Eszopiclone 3 mg and sodium oxybate 4.5 g showed a beneficial effect on the severity of OSA with a reduction in AHI and may merit further assessment as a potential therapeutic option for a subgroup of patients with OSA. Only one trial assessed the effect of an opioid (remifentanil); some studies included CPAP treatment, whilst in a significant number of participants, previous treatment with CPAP was not stated and thus a residual treatment effect of CPAP could not be excluded. Most studies were small and of short duration, with indiscernible methodological quality.Caution is therefore required when such agents are prescribed for patients with OSA, especially outside the severity of the OSA cohorts and the corresponding dose of compounds given in the particular studies. Larger, longer trials involving patients across a broader spectrum of OSA severity are needed to clarify these results.

Drug therapy for obstructive sleep apnoea in adults.

BACKGROUND: The treatment of choice for moderate to severe obstructive sleep apnoea (OSA) is continuous positive airways pressure (CPAP) applied via a mask during sleep. However, this is not tolerated by all individuals and its role in mild OSA is not proven. Drug therapy has been proposed as an alternative to CPAP in some patients with mild to moderate sleep apnoea and could be of value in patients intolerant of CPAP. A number of mechanisms have been proposed by which drugs could reduce the severity of OSA. These include an increase in tone in the upper airway dilator muscles, an increase in ventilatory drive, a reduction in the proportion of rapid eye movement (REM) sleep, an increase in cholinergic tone during sleep, an increase in arousal threshold, a reduction in airway resistance and a reduction in surface tension in the upper airway. OBJECTIVES: To determine the efficacy of drug therapies in the specific treatment of sleep apnoea. SEARCH METHODS: We searched the Cochrane Airways Group Specialised Register of trials. Searches were current as of July 2012. SELECTION CRITERIA: Randomised, placebo controlled trials involving adult patients with confirmed OSA. We excluded trials if continuous positive airways pressure, mandibular devices or oxygen therapy were used. We excluded studies investigating treatment of associated conditions such as excessive sleepiness, hypertension, gastro-oesophageal reflux disease and obesity. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures recommended by The Cochrane Collaboration. MAIN RESULTS: Thirty trials of 25 drugs, involving 516 participants, contributed data to the review. Drugs had several different proposed modes of action and the results were grouped accordingly in the review. Each of the studies stated that the participants had OSA but diagnostic criteria were not always explicit and it was possible that some patients with central apnoeas may have been recruited.Acetazolamide, eszopiclone, naltrexone, nasal lubricant (phosphocholinamine) and physiostigmine were administered for one to two nights only. Donepezil in patients with and without Alzheimer's disease, fluticasone in patients with allergic rhinitis, combinations of ondansetrone and fluoxetine and paroxetine were trials of one to three months duration, however most of the studies were small and had methodological limitations. The overall quality of the available evidence was low.The primary outcomes for the systematic review were the apnoea hypopnoea index (AHI) and the level of sleepiness associated with OSA, estimated by the Epworth Sleepiness Scale (ESS). AHI was reported in 25 studies and of these 10 showed statistically significant reductions in AHI.Fluticasone in patients with allergic rhinitis was well tolerated and reduced the severity of sleep apnoea compared with placebo (AHI 23.3 versus 30.3; P < 0.05) and improved subjective daytime alertness. Excessive sleepiness was reported to be altered in four studies, however the only clinically and statistically significant change in ESS of -2.9 (SD 2.9; P = 0.04) along with a small but statistically significant reduction in AHI of -9.4 (SD 17.2; P = 0.03) was seen in patients without Alzheimer's disease receiving donepezil for one month. In 23 patients with mild to moderate Alzheimer's disease donepezil led to a significant reduction in AHI (donepezil 20 (SD 15) to 9.9 (SD 11.5) versus placebo 23.2 (SD 26.4) to 22.9 (SD 28.8); P = 0.035) after three months of treatment but no reduction in sleepiness was reported. High dose combined treatment with ondansetron 24 mg and fluoxetine 10 mg showed a 40.5% decrease in AHI from the baseline at treatment day 28. Paroxetine was shown to reduce AHI compared to placebo (-6.10 events/hour; 95% CI -11.00 to -1.20) but failed to improve daytime symptoms.Promising results from the preliminary mirtazapine study failed to be reproduced in the two more recent multicentre trials and, moreover, the use of mirtazapine was associated with significant weight gain and sleepiness. Few data were presented on the long-term tolerability of any of the compounds used. AUTHORS' CONCLUSIONS: There is insufficient evidence to recommend the use of drug therapy in the treatment of OSA. Small studies have reported positive effects of certain agents on short-term outcomes. Certain agents have been shown to reduce the AHI in largely unselected populations with OSA by between 24% and 45%. For donepezil and fluticasone, studies of longer duration with a larger population and better matching of groups are required to establish whether the change in AHI and impact on daytime symptoms are reproducible. Individual patients had more complete responses to particular drugs. It is possible that better matching of drugs to patients according to the dominant mechanism of their OSA will lead to better results and this also needs further study.

Gait and posture analysis in patients with maxillary transverse discrepancy, before and after RPE.

AIM: The purpose of this study was to evaluate the effects of the rapid palatal expansion (RPE) on posture and gait analysis in subjects with maxillary transverse discrepancies. MATERIAL AND METHODS: Forty-one patients between 6 and 12 years were divided into 3 groups: 10 control subjects (Cs), 16 patients with unilateral posterior crossbite (CbMono), 15 patients with maxillary transverse discrepancy and no crossbite (Nocb). Every subject underwent gait analysis and posturographic examination in order to evaluate the presence of balance alterations before (T0) and after (T4) RPE application. The examinations were performed through a six-cameras stereophotogrammetric system (60-120Hz, BTS S.p.A.) synchronized with two force plates (FP4060, Bertec Corp.). Romberg test was performed on a force plate, and the statokinesiogram and joint kinematics were evaluated. One-way Anova was performed among the variables after evidence of normal distribution (Levene's test for equality of variances) and Kruskal-Wallis test (P<0.05), in order to compare the three groups of subjects. While paired t-test was performed, or Kruskal-Wallis test, instead when comparing pre- and post-RPE application within the same group of subjects (P<0.05). Tamane T2 or Bonferroni correction was applied where needed. RESULTS: The posturographic analysis reveal significant differences across the 3 population: 95% power frequency in medio-lateral and antero-posterior direction in T0, median frequency in medio-lateral direction in T0, mean power frequency in medio-lateral direction in T0. Significant differences were also registered in the three-dimensional joints kinematics variables, mainly between Cs and Cbmono in T0 and T4 and between Cbmono and Nocb in T4. CONCLUSIONS: A detectable correlation between dental occlusion and body posture is shown in this study that confirms another benefit of the RPE. This was mainly revealed in the dynamic posture where modifications at the mandibular level affect the whole body.

Association between severity of untreated sleep apnoea and postoperative complications following major cardiac surgery: a prospective observational cohort study.

OBJECTIVE: To examine whether untreated sleep apnoea is associated with prolonged Intensive Care Unit (ICU) stay and increased frequency of postoperative ICU complications, in patients undergoing major cardiac surgery. PATIENTS/METHODS: Adult patients, undergoing elective coronary artery bypass grafting with or without cardiac valve surgery, between March 2013 and July 2014, were considered. We excluded patients participating in other interventional studies, those who had a tracheostomy before surgery, required emergency surgery or were due to be admitted on the day of surgery. Patients underwent inpatient overnight oximetry on the night prior to their surgery to assess for the presence of sleep apnoea. Since oximetry alone cannot differentiate obstructive from central apnoea, the results are reported as sleep apnoea which was diagnosed in patients with an arterial oxygen desaturation index (ODI) ≥ 5/h. RESULTS: The primary outcome measure was length of stay (LoS) in ICU in days. The secondary outcome was a composite measure of postoperative complications in ICU. Multivariate models were developed to assess associations between ODI and the primary and secondary outcome measures, adjusting for preselected predictor variables, relative to primary and secondary outcomes. There was no significant association between ODI and ICU LoS, HR 1.0, 95% CI 0.99-1.02; p = 0.12. However we did find a significant association between ODI and postoperative complications in the ICU, OR = 1.1; 95% CI 1.02-1.17; p = 0.014. The probability of developing complications rose with higher ODI, reflecting sleep apnoea severity. CONCLUSIONS: Acknowledging the limitations of this prospective study, untreated sleep apnoea did not predict an increased length of stay in ICU but we do report an association with postoperative complications in patients undergoing major cardiac surgery.

A case of orthodeoxia platypnoea in a patient with adult polycystic kidney and liver disease with a patent foramen ovale.

We describe a case of a patient with polycystic kidney and liver disease presenting with a 4 year history of shortness of breath. This was caused by a liver cyst pressing on the inferior vena cava, right atrium and ventricle, leading to a right to left shunt across a patent foramen ovale. This is consistent with the condition Orthodeoxia Platypnoea, which occurs when desaturation and dyspnoea occur in the upright position in association with an intra atrial shunt.