Semi-Solid Dosage Forms Containing Pranoprofen-Loaded NLC as Topical Therapy for Local Inflammation: In Vitro, Ex Vivo and In Vivo Evaluation.

Pranoprofen (PRA)-loaded nanostructured lipid carriers (NLC) have been dispersed into blank gels composed of 1% of Carbomer 940 (PRA-NLC-Car) and 3% of Sepigel® 305 (PRA-NLC-Sep) as a novel strategy to refine the biopharmaceutical profile of PRA, for dermal administration in the treatment of skin inflammation that may be caused by possible skin abrasion. This stratagem intends to improve the joining of PRA with the skin, improving its retention and anti-inflammatory effect. Gels were evaluated for various parameters such as pH, morphology, rheology, and swelling. In vitro drug release research and ex vivo permeation through the skin were carried out on Franz diffusion cells. Additionally, in vivo assays were carried out to evaluate the anti-inflammatory effect, and tolerance studies were performed in humans by evaluating the biomechanical properties. Results showed a rheological profile common of semi-solid pharmaceutical forms for dermal application, with sustained release up to 24 h. In vivo studies using PRA-NLC-Car and PRA-NLC-Sep in Mus musculus mice and hairless rats histologically demonstrated their efficacy in an inflammatory animal model study. No signs of skin irritation or modifications of the skin's biophysical properties were identified and the gels were well tolerated. The results obtained from this investigation concluded that the developed semi-solid formulations represent a fitting drug delivery carrier for PRA's transdermal delivery, enhancing its dermal retention and suggesting that they can be utilized as an interesting and effective topical treatment for local skin inflammation caused by a possible abrasion.

COVID-19 infection rate after urgent versus elective total hip replacement among unvaccinated individuals: A multicenter prospective cohort amid the COVID-19 pandemic.

Background: Due to the COVID-19 pandemic, hospitals have become unsafe for patients as potential sources of virus transmission. This study aims to determine the COVID-19 infection rate after primary total hip arthroplasty (THA) among unvaccinated patients. THA patients undergoing elective or traumatic (urgent) THA were compared regarding COVID-19 contraction. Methods: Primary THA patients were prospectively followed from three hospitals in *two great cities* of the country between April 2020 to August 2021. If the patient had suspected COVID-19 symptoms, had a SARS-CoV-2 PCR test from nasopharyngeal and oropharyngeal swabs and/or chest CT scan. Results: Finally, information was received from 436 patients, including 345 (79.1%) elective and 91 (20.9%) traumatic THAs. Eight patients (1.8%) contracted COVID-19 within a month after THA discharge, and two died due to COVID-19. There was no statistical difference between COVID-19 disease and type of surgery (elective 1.4% versus traumatic 3.3%, P = 0.24). Women (Odds ratio (95% CI) = 8.5 (2.1-35.2), P = 0.01) and those who have heart disease (Odds ratio with Haldane-Anscombe correction ≈ 14.0, P = 0.01) were more likely to contract COVID-19 postoperatively. Conclusion: In both elective and urgent cases of THA, researchers found that there is not a high risk of contracting the virus during the peri-surgery period. Urgent THA surgeries are comparable to elective THA-with those strict pre-elective surgery protocols-in terms of COVID-19 risk of infection from the hospital stay if appropriate health protocols are followed.

Determining the accuracy of preoperative total hip replacement 2D templating using the mediCAD® software.

BACKGROUND: Templating is a preoperative planning procedure that improves the efficiency of the surgical process and reduces postoperative complications of total hip arthroplasty (THA) by improving the precision of prediction of prosthetic implant size. This study aimed to evaluate the accuracy of the preoperative cup and stem size digital 2D templating of THA with mediCAD® software and find the factors that influence the accuracy, such as indication for surgery, patients' demographics, implant brand, and the assessors' grade of education. METHODS: We retrospectively retrieved 420 patient template images of all patients who underwent THA between March 2018 and March 2021. Templating of all included images was processed using mediCAD® software a day before surgery by a newcomer physician to hip arthroplasty course (PGY-2 orthopedic resident or hip surgery fellow). Preoperative templating cup and stem sizes were compared with the actual inserted implant sizes. RESULT: After excluding ineligible patients, this study included 391 patients, 193 (49.4%) males and 198 (50.6%) females with a mean age of 43.3 ± 14.9. The average cup sizes predicted before and after surgery were 52.12 ± 14.28 and 52.21 ± 15.05 respectively, and the mean delta cup size (before and after surgery) was 2.79 ± 2.94. The delta stem size before and after surgery has a mean value of 1.53 ± 1.49. The acetabular cup components, measured within ± 0, ± 1, and ± 2 sizes, were 28.9%, 63.9%, 83.1% accurate, respectively. The femoral stem design component measured within ± 0, ± 1, and ± 2 sizes were 27.2%, 61.0%, 78.6% accurate, respectively. Wagner Cone® stem brand, DDH patients, and females showed significantly higher accuracy of stem size templating. Revision THA has the lowest accuracy in terms of cup size templating. The compression of accuracy rate between resident and fellow revealed no significant differences. Also, no significant difference was detected between the accuracy of templating performed in the first months with the second months of the arthroplasty course period. CONCLUSION: Our study showed that under mentioned condition, templating using mediCAD® has acceptable accuracy in predicting the sizes of femoral and acetabular components in THA patients. Digital software like mediCAD® remains favorable because of the short learning curve, user-friendly features, and low-cost maintenance, leading to level-up patient care and THA efficacy. Further studies are necessary for clarifying the role of the assessor's experience and expertise in THA preoperative templating. LEVEL OF EVIDENCE: Level III (retrospective observational study).

Paraesophageal hernia repair in elderly patients: outcomes from a 10-year retrospective study.

BACKGROUND: Laparoscopic surgery has become the preferred management for paraesophageal hernias (PEH); however surgical management versus watchful waiting remains controversial in older patients. METHODS: This retrospective study analyzed the outcomes of PEH repair in elderly patients surgically managed at The Ottawa Hospital over a 10-year period. Patients older than 60 years who underwent PEH repair were examined with respect to presentation, technique and associated complications. RESULTS: Despite similar demographics, our study groups showed significantly different characteristics of surgical techniques. Most surgeries were performed laparoscopically; however, patients aged 70 years or older underwent more open and emergency surgeries than the younger group. Despite a 30-day postoperative complication rate of 45 % and 13 % in the older (≥ 70 yr) and younger (60-69 yr) groups, respectively, the rates during elective repair were similar. There were no deaths in the younger group, whereas the 30-day mortality rate was 5 % in patients aged 70 years and older, including a 2-fold increase with emergency repair (4 v. 2 patients). CONCLUSION: Management of PEH in older adults remains controversial in relation to a surgical versus watchful waiting approach. We found that in patients aged 70 years and older who undergo surgical management of PEH experience more open and emergency procedures, which are associated with higher complication rates. However, in the elective setting older patients had increased laparoscopic repairs and comparable complication rates to younger patients. We found the greatest outcomes with early, elective laparoscopic repair, irrespective of age.

The effect of peer mentoring on motivation and self-regulated learning in medical students during transition.

BACKGROUND: Self-regulated learning (SRL) is a critical skill for medical students to reach their learning goals in the bedside clinical rotations. This study was performed with the aim of comparing SRL and motivation of 4th year medical students who are in their educational transition between students with mentors and those without mentors. MATERIALS AND METHODS: This study was cross-sectional. A total of 196 medical students were invited to complete a form consisting the motivation and SRL questionnaire through Google form during their 1st year of clinical clerkship, while some of them had participated in the mentoring program beforehand. data correlation and regression analysis were employed. RESULTS: Comparing SRL and motivational beliefs scores between students with mentors and without mentors indicated that motivational beliefs mean score in students with mentors (87.5 ± 8.44) was significantly higher compared to the others (83.49 ± 7.36) (P = 0.005). Among SRL subscales, planning and examination stress were significantly different between two groups with higher scores for mentees (P = 0.033 and 0.021). Having a mentor predicted motivational beliefs with OR = 7.974 (1.391-45.719) and P = 0.020. CONCLUSION: Considering a significant correlation between mentor possession and the scale of motivation beliefs, future longitudinal and interventional research besides the customized mentoring program is required to understand the role of mentoring programs on SRL as a cause-and-effect relationship to recommend the peer mentoring program to enhance SRL skills in the medical students especially during their transition to the new clinical environment.

Effects of preoperative melatonin on postoperative pain following cesarean section: A randomized clinical trial.

BACKGROUND: Data regarding the analgesic effects of melatonin after the surgery is scare. So far, only one study has investigated the analgesic effect of melatonin during cesarean section. Objective: The present study was performed to investigate the effect of preoperative oral melatonin on pain intensity after cesarean section during spinal anesthesia. METHODS: In a double-blind randomized controlled clinical trial study, 204 patients undergoing elective cesarean section with class 1 and 2 anesthesia (ASA) were enrolled. Patients were randomly divided into 3 groups of 68 patients. Patients in group A were given 5 mg melatonin tablets, patients in group B were given 10 mg melatonin tablets, and group C was given placebo. All patients underwent spinal anesthesia with the same anesthesia protocol. Pain intensity, nausea, vomiting, pruritus and headache were assessed and recorded 2, 6, 12 and 24 h after surgery. The time of first dose of analgesia, the amount of opioid consumed within 24 h, and the time to resume physical activity was also recorded. Statistical analysis of data was performed using SPSS 20 software. RESULTS: Repeated measurements of pain intensity during the study showed that in all 3 groups pain intensity was significantly reduced during the study, p < 0.001, respectively. The intensity of pain was significantly different in groups B and C, groups B and A and groups A and C, P < 0.001, respectively. The pain reduction was greatest in group B, followed by group A and group C, respectively. The time interval between the end of surgery and the patient's need for analgesia was significant in group B compared to group A (P = 0.035) and C (P < 0.001) and also in group A compared to group C (P = 0.011). The mean dose of opioid was significantly least in group B, p < 0.001. The mean time to resume physical activity was also shortest in group B, p < 0.001 Headache and nausea/vomiting were observed in 7 patients (10.7%) group A and 7 patients (10.7%) in group C. None of the patients in group B developed complications. CONCLUSION: The results of the present study showed that the use of 10 mg of melatonin before cesarean section with spinal anesthesia is not only safe, but also reduces the severity of patients' pain, increases the duration of postoperative analgesia, reduces the need for analgesics after surgery and resumption of physical activity.

Impact of the integrated comprehensive care program post-thoracic surgery: A propensity score-matched study.

OBJECTIVE: Thoracic surgery is associated with significant rates of postoperative morbidity and postdischarge return to the hospital or emergency department (ED). This study aims to assess the impact of a novel integrated patient-centered, hospital-based multidisciplinary community program (Integrated Comprehensive Care [ICC]) on postdischarge outcomes in patients undergoing thoracic surgery compared to routine care. METHODS: This was a retrospective cohort study of patients who underwent surgical resection for lung malignancies at a tertiary care center from 2010 to 2014. Patients were divided into 2 cohorts based on their enrollment in the ICC program (intervention cohort; 2012-2014) or routine postoperative care (control cohort; 2010-2012). Propensity score matching was performed to match the 2 cohorts. The impact of the ICC program on postoperative length of stay (LOS), rate of ED visits, readmissions, and mortality within the first 60 days was assessed. RESULTS: Of the 1288 patients included in this study, 658 (51.1%) were male patients with mean age of 64 years (standard deviation 14.1 years). After propensity score matching, 478 patients were enrolled in the ICC cohort and 592 were enrolled as controls. The ICC cohort had significantly shorter LOS (4 days, vs 5 days in controls, P = .001), lower rate of 60-day ED visits (9.8% vs 28.4% in controls, P < .001), and readmissions (6.9% vs 8.6% in controls, P < .001). The 60-day mortality was also significantly lower in the ICC cohort compared with the control group (0.6% vs 0.8% in controls, P < .001). CONCLUSIONS: The ICC program is associated with shorter LOS, fewer ED visits and readmissions after discharge, and ultimately may decrease postoperative mortality.

EEG-based classification of epilepsy and PNES: EEG microstate and functional brain network features.

Epilepsy and psychogenic non-epileptic seizures (PNES) often show over-lap in symptoms, especially at an early disease stage. During a PNES, the electrical activity of the brain remains normal but in case of an epileptic seizure the brain will show epileptiform discharges on the electroencephalogram (EEG). In many cases an accurate diagnosis can only be achieved after a long-term video monitoring combined with EEG recording which is quite expensive and time-consuming. In this paper using short-term EEG data, the classification of epilepsy and PNES subjects is analyzed based on signal, functional network and EEG microstate features. Our results showed that the beta-band is the most useful EEG frequency sub-band as it performs best for classifying subjects. Also the results depicted that when the coverage feature of the EEG microstate analysis is calculated in beta-band, the classification shows fairly high accuracy and precision. Hence, the beta-band and the coverage are the most important features for classification of epilepsy and PNES patients.

Development of a clinical score to distinguish malignant from benign esophageal disease in an undiagnosed patient population referred to an esophageal diagnostic assessment program.

BACKGROUND: Esophageal cancer is associated with poor prognosis. Diagnosis is often delayed, resulting in presentation with advanced disease. We developed a clinical score to predict the risk of a malignant diagnosis in symptomatic patients prior to any diagnostic tests. METHODS: We analyzed data from patients referred to a regional esophageal diagnostic assessment program between May 2013 and August 2016. Logistic regression was performed to identify predictors of malignancy based on patient characteristics and symptoms. Predicted probabilities were used to develop a score from 0 to 10 which was weighted according to beta coefficients for predictors in the model. Score accuracy was evaluated using a receiver operating characteristic (ROC) curve and internally validated using bootstrapping techniques. Patients were classified into low (0-2 points), medium (3-6 points), and high (7-10 points) risk groups based on their scores. Pathologic tissue diagnosis was used to assess the effectiveness of the developed score in predicting the risk of malignancy in each group. RESULTS: Of 530 patients, 363 (68%) were diagnosed with malignancy. Factors predictive of malignancy included male sex, family history of cancer and esophageal cancer, fatigue, chest/throat/back pain, melena and weight loss. These factors were allocated 1-2 points each for a total of 10 points. Low-risk patients had 70% lower chance of malignancy (RR =0.28, 95% CI: 0.21-0.38), medium-risk had 50% higher chance of malignancy (RR =1.5, 95% CI: 1.26-1.77), and high-risk patients were 8 times more likely to be diagnosed with malignancy (RR =8.2, 95% CI: 2.60-25.86). The area under the ROC curve for malignancy was 0.82 (95% CI: 0.77-0.87). CONCLUSIONS: A simple score using patient characteristics and symptoms reliably distinguished malignant from benign diagnoses in a population of patients with upper gastrointestinal symptoms. This score might be useful in expediting investigations, referrals and eventual diagnosis of malignancy.

Intraoperative extracorporeal membrane oxygenation and the possibility of postoperative prolongation improve survival in bilateral lung transplantation.

OBJECTIVES: The value of intraoperative extracorporeal membrane oxygenation (ECMO) in lung transplantation remains controversial. In our department, ECMO has been used routinely for intraoperatively unstable patients for more than 15 years. Recently, we have extended its indication to a preemptive application in almost all cases. In addition, we prolong ECMO into the early postoperative period whenever graft function does not meet certain quality criteria or in patients with primary pulmonary hypertension. The objective of this study was to review the results of this strategy. METHODS: All standard bilateral lung transplantations performed between January 2010 and June 2016 were included in this single-center, retrospective analysis. Patients were divided into 3 groups: group I-no ECMO (n = 116), group II-intraoperative ECMO (n = 343), and group III-intraoperative and prolonged postoperative ECMO (n = 123). The impact of different ECMO strategies on primary graft function, short-term outcomes, and patient survival were analyzed. RESULTS: The use of intraoperative ECMO was associated with improved 1-, 3-, and 5-year survival compared with non-ECMO patients (91% vs 82%, 85% vs 76%, and 80% vs 74%; log-rank P = .041). This effect was still evident after propensity score matching of both cohorts. Despite the high number of complex patients in group III, outcome was excellent with higher survival rates than in the non-ECMO group at all time points. CONCLUSIONS: Intraoperative ECMO results in superior survival when compared with transplantation without any extracorporeal support. The concept of prophylactic postoperative ECMO prolongation is associated with excellent outcomes in recipients with pulmonary hypertension and in patients with questionable graft function at the end of implantation.

Impact of surgical approach on perioperative and long-term outcomes following esophagectomy for esophageal cancer.

BACKGROUND: Surgical resection remains a critical component of esophageal cancer treatment with curative-intent. The aim of this study was to compare open (OE) to minimally invasive Ivor Lewis esophagectomy (MIE) with respect to perioperative and oncologic outcomes. METHODS: Retrospective single-institution review of MIE and OE patients operated between 2001 and 2015 was conducted. Univariable and multivariable models were created using Cox regression. The Kaplan-Meier method was used to compare oncologic outcomes. Propensity score matching was used to compare oncological outcomes in MIE and OE patients. RESULTS: Of 210 esophageal resection patients, 47% had OE (137/291) and 25% had MIE (73/291). The MIE and OE groups were comparable with respect to patient factors and operative details. Fewer OE patients received neoadjuvant chemoradiation. MIE was associated with improved lymph node yield, (MIE = 30 [IQR:22-39]; OE = 14 [IQR:7-19], p < 0.001), less intraoperative blood loss (MIE = 312 mL [100-400]; OE = 657 mL [350-700], p < 0.001), and shorter median length of stay (MIE = 10 days [IQR = 8-14]; OE = 14 days [IQR = 11-22] p < 0.01). The OE group had significantly more adverse events resulting in reoperation or intensive care unit admission (MIE = 21%; OE = 34%; p < 0.01). On multivariable analysis, age and positive resection margins were associated with decreased odds of survival. The number of lymph nodes retrieved, positive resection margins, and pathologic stage were significant predictors of disease-free survival. Analysis of 69 matched pairs showed equivalent median overall survival (MIE = 49 months [18-67]; OE = 29 months [17-69]; p = 0.26) and disease-free survival (MIE = 9 [6-22]; OE = 13 [6-22]; p = 0.45) between the two groups. CONCLUSIONS: Although long-term oncologic outcomes appear to be similar, MIE is associated with significantly less intraoperative blood loss, improved lymph node yield, less risk of severe postoperative adverse events, and shorter length of stay.

Role of Evidence-Based Reviews in Surgery in teaching critical appraisal skills and in journal clubs.

BACKGROUND: Evidence-Based Reviews in Surgery (EBRS) is a program developed to teach critical appraisal skills to general surgeons and residents. The purpose of this study was to assess the use of EBRS by general surgery residents across Canada and to assess residents' opinions regarding EBRS and journal clubs. METHODS: We surveyed postgraduate year 2-5 residents from 15 general surgery programs. Data are presented as percentages and means. RESULTS: A total of 231 residents (58%, mean 56% per program, range 0%-100%) responded: 172 (75%) residents indicated that they know about EBRS and that it is used in their programs. More than 75% of residents who use EBRS agreed or strongly agreed that the EBRS clinical and methodological articles and reviews are relevant. Only 55 residents (24%) indicated that they used EBRS online. Most residents (198 [86%]) attend journal clubs. The most common format is a mandatory meeting held at a special time every month with faculty members with epidemiological and clinical expertise. Residents stated that EBRS articles were used exclusively (13%) or in conjunction with other articles (57%) in their journal clubs. Most respondents (176 of 193 [91%]) stated that journal clubs are very or somewhat valuable to their education. CONCLUSION: The EBRS program is widely used among general surgery residents across Canada. Although most residents who use EBRS rate it highly, a large proportion are unaware of EBRS online features. Thus, future efforts to increase awareness of EBRS online features and increase its accessibility are required.

CONTEXTE: Le programme de revues factuelles en chirurgie EBRS (Evidence-Based Reviews in Surgery) a été mis au point pour enseigner aux chirurgiens et aux résidents en chirurgie générale les compétences nécessaires pour faire des évaluations critiques. Le but de cette étude était d'analyser l'utilisation des EBRS par les résidents en chirurgie générale au Canada et de leur demander leur opinion au sujet des EBRS et des clubs de lecture. MÉTHODES: Nous avons interrogé des résidents des années 2 à 5 rattachés à 15 programmes de chirurgie générale. Les données sont présentées sous forme de pourcentages et de moyennes. RÉSULTANTS: En tout, 231 résidents (58 %, moyenne de 56 % par programme, intervalle 0 %­100 %) ont répondu : 172 résidents (75 %) ont indiqué qu'ils connaissent les EBRS et que leur programme les utilise. Plus de 75 % des résidents qui utilisent les EBRS se sont dit d'accord ou tout à fait d'accord avec l'énoncé sur la pertinence des articles et revues cliniques et méthodologiques des EBRS. Seulement 55 résidents (24 %) ont dit utiliser les EBRS en ligne. La plupart des résidents (198 [86 %]) participaient à des clubs de lecture. Leur utilisation la plus courante prend la forme d'une réunion obligatoire tenue à un moment particulier tous les mois avec les enseignants de la faculté ayant une expertise épidémiologique et clinique. Les résidents ont indiqué que les EBRS étaient utilisés seuls (13 %) ou avec d'autres articles (57 %) dans leurs clubs de lecture. La plupart des répondants (176 sur 193 [91 %]) ont affirmé que leurs clubs de lecture sont très ou assez utiles pour leur formation. CONCLUSIONS: Le programme EBRS est largement utilisé par les résidents en chirurgie générale au Canada. Même si la plupart des résidents qui utilisent les EBRS leur accordent une cote élevée, une forte proportion ignore l'existence des possibilités web des EBRS. Il faudra donc travailler à mieux faire connaître les possibilités offertes par le programme EBRS sur le web et en faciliter l'accès.

Teaching evidence based medicine to surgery residents-is journal club the best format? A systematic review of the literature.

OBJECTIVE: Systematic reviews were performed to assess methods of teaching the evidence-based medicine (EBM) process and determine which format or what components of journal club appear to be most effective in teaching critical appraisal skills to surgical residents and have the highest user satisfaction. DESIGN: MEDLINE, Embase, Web of Science, AMED, PsychINFO, PubMed, Cochrane Library, and Google scholar were searched to identify relevant articles. To be included, studies had to provide details about the format of their EBM curriculum or journal club and report on the effectiveness or participant satisfaction. Potentially relevant articles were independently reviewed by 2 authors and data were extracted on separate data forms. RESULTS: Seven studies met the inclusion criteria for assessment of teaching EBM and 8 studies (including 3 in the EBM systematic review) met criteria for assessment of journal club format. Overall, study quality was poor. Only 2 studies were randomized controlled trials. Five were before-after studies, which showed significant improvement in critical appraisal skills or statistical knowledge following an EBM course or journal club. The 2 randomized controlled trials (RCTs) compared teaching EBM or critical appraisal skills in lecture format or journal club to online learning. There was no significant difference in mean scores in 1 study whereas the other reported significantly better scores in the journal club format. Four studies reported high participant satisfaction with the EBM course or journal club format. CONCLUSIONS: There is some evidence that courses with or without the addition of journal clubs lead to improved knowledge of the EBM process although the impact on patient care is unknown. Journal clubs seem to be the preferred way of teaching critical appraisal skills but while some components of journal clubs are favored by participants, it remains unclear which elements are most important for resident learning.

Overview of obstructive sleep apnea in children: exploring the role of dentists in diagnosis and treatment.

Among the many factors important in children"s development is sleep. Sleep disorders can impair children"s sleep and lead to negative consequences. Obstructive sleep apnea (OSA), which involves blockage of the airway during sleep, can affect development and behaviour; thus, OSA in children should be diagnosed and treated at an early stage. One of the main causes of childhood OSA is enlargement of the tonsil tissues and, in most cases, their removal serves as an ultimate treatment of OSA. However, it remains unclear what proportion of children with enlarged tonsil tissue suffer from OSA. Dentists are becoming increasingly aware of the issue of OSA as they are sometimes involved in treatment of this condition using oral appliances. Moreover, as dentists often look into children"s mouths, they can play an active role in identifying those with enlarged tonsils and referring them for sleep assessment.

Clinical diagnosis of sleep apnea based on single night of polysomnography vs. two nights of polysomnography.

PURPOSE: The purpose of this study was to investigate apnea-hypopnea index (AHI) across two polysomnographies (PSGs) to examine AHI variability and impact on clinical diagnosis. MATERIALS AND METHODS: Two-night PSGs of 193 sleep clinic patients were reviewed, and the AHI variability was analyzed. Anonymized records from five patients with significant night-to-night AHI variability were used in this study: the two-night PSGs from two patients were represented as four individual PSGs; the two-night PSG for two others were represented as being obtained from two different sleep clinics; the last patient's PSG was shown as a two-night study. Twenty-two sleep experts attending the Associated Professional Sleep Societies meeting were recruited to make diagnoses based on the PSGs. They were told that the PSGs were from seven patients: four with single-night PSG; two with two PSGs, each one from a different clinic; and one patient with a two-night PSG. RESULTS: Twenty-one percent of the 193 sleep clinic patients had a nightly PSG AHI variability of greater than 5. Forty-eight percent of all patients had a significantly higher AHI on the first night, and 41% had a significantly higher AHI on the second night. Using an AHI > 15 diagnostic criteria, sleep apnea would have been undetected in 20% (n = 39) of patients due to low AHI on one night. Furthermore, 13% of all patients had a more severe sleep apnea classification based on the second night of PSG. For the seven cases, 27-36% of sleep experts failed to identify sleep apnea especially when presented with the PSG containing the lower AHI. Incidences of missed sleep apnea diagnoses were reduced to 15-18% when information from two PSGs was presented to the sleep experts. CONCLUSIONS: Utilizing a large patient population, this study supports the significant night-to-night variability in PSG respiratory variables. Identification of sleep apnea in some patients is reduced when sleep experts are provided with only one PSG recording. The clinical implication is that about 13% of sleep clinic patients might benefit from a second night of PSG.

The Berlin questionnaire for sleep apnea in a sleep clinic population: relationship to polysomnographic measurement of respiratory disturbance.

The Berlin questionnaire (BQ) has been used to help identify patients at high risk of having sleep apnea in primary care and atrial fibrillation patients. The BQ may be a useful adjunct in sleep medicine and research, but it has never been validated in a sleep clinic population. The aim of the study is to determine the specificity and sensitivity of the BQ compared to the respiratory disturbance index (RDI) values obtained from two nights of polysomnographic recording in a sleep clinic population. This is a retrospective chart review study of 130 sleep clinic patients. Patients' demographics, BQ scores, RDI measurements, and sleep study parameters were extracted from the patients' chart. Of the 130 charts reviewed, the BQ identified 76 (58.5%) as being at high-risk of having sleep apnea, but overnight polysomnography found only 34 of the 130 patients (26.2%) had an RDI > 10. The BQ performed with 0.62 sensitivity and 0.43 specificity at the RDI > 10 level. Due to the low sensitivity and specificity as well as the large number of false negatives and positives, the Berlin questionnaire is not an appropriate instrument for identifying patients with sleep apnea in a sleep clinic population.