Research Critique, Part 2: Critique of Quantitative Research Article The population who are diagnosed with obstructive sleep apnea (OSA) often experience daytime drowsiness and are at risk for ischemic heart disease, arrhythmias, hypertension, and other vascular related problems (Hsu et al., 2007). There are several treatment options for people with OSA, which are weight loss, continuous positive airway pressure (CPAP), dental appliances, and surgical procedure. This study evaluates patients who have undergone uvulopalatopharyngoplasty (UPPP) to determine improvement and changes in surgical parameters of their upper airway using quantitative videoendoscopic computer-assisted measurement (CAM) in hopes of showing improvement in the apnea-hypopnea index (AHI).
Protection of Human Participants
The authors describe this study as prospective in design. The study was conducted to evaluate the efficacy of UPPP, a surgical procedure for OSA, on patients who had surgery six months prior (Hsu et al., 2007). It is presumed every patient gave consent for the surgical procedure. An assumption may be made that subjects were voluntary for the post surgical study because there was no mention of further consents. It is not stated that this study had approval from an institutional review board from the agency. The 19 male patients participated in overnight pre and postoperative non-invasive polysomnnographic studies (PSG).
These tests include the Epworth sleepiness scale recording, CAM of upper airway, and bio-data recording. PSG entails electroencephalogram (EEG), submental electromyogram (EMG), anterior tibialis EMG, electrocardiogram (ECG), thoraco-abdominal motion, oronasal airflow (expired CO2), arterial oxygen saturation with pulse oximetry, and electrooculography (EOG). Images were recorded for comparison evaluation postoperatively. The mean age of the subjects was 40.6 years with a mean body mass index (BMI) of 29.4, all who had UPPP after failing the CPAP trial and other medical methods.
Data Collection and Analysis
The major variables were labeled in association with the endoscopic photographs from the computer-assisted measurement (CAM) airway analysis at the retropalatal level with calibrator in regards to showing airway dimensions in both pre and postoperative images (Hsu et al., 2007). There was no sign of manipulation of these variables other than from the postoperative images. The research team compiled the data to show the regression data of UPPP surgery were considerably correlated with postoperative improvement. This method of data collection was used to analyze the correlation between modifications in surgical parameters and the postoperative status of OSA patients. The six-month postoperative, patients again underwent PSG, Epworth sleepiness scale recording, CAM of upper airway, and bio-data analysis.
A total of eight videoendoscopic images were taken of all 19 subjects. Patients were analyzed during quiet respiration and Mueller’s maneuver in both supine and erect positions at the retropalatal and retrolingual levels. The Mueller’s maneuver is a non-invasive procedure using fiber optic endoscopic evaluation that measures both size, shape, and collapsibility of the upper airway (Friedman, 2009). Images were captured using a videocapture card, which was installed into the computer along with digital imaging software. Transverse and longitudinal dimensions, as well as surface areas were measured using digital software to calculate the collapsibility of obstructive sites of the upper airway. Comparison was made between pre and postoperative images, which show significant improvement of the retropalatal area by 70% (Hsu et al., 2007).
Data Management and Analysis
The author indicates that the researcher who performed the upper airway measurements was not privy to patient information whether they were of preoperative or postoperative status (Hsu et al., 2007). Following UPPP, the importance (p<0.05) of change in parameters was tested using the Wilcoxon’s signed-rank test. The Wilcoxon’s signed-ranked test was used because there are two nominal variables (before and after) and one measurable variable (the subject) (McDonald, 2009). It was not conveyed if statistical software was utilized but simple regression was used to correlate the pre and postoperative differences in surgical limitations with the AHI to detect the parameters that would considerably improve the results of OSA surgery. Analysis of the data was straight forward in that it compared measurements of pre and postoperative images taken.
Findings/Interpretation of Findings
According to the results of the data, the researchers found there was significant improvement of the AHI in level one palatal surgery (Hsu et al., 2007). The UPPP procedure increased the retropalatal area significantly by 70%, transverse and longitudinal diameters approximately 40% and 31%, and palatal collapsibility decreased by about 60%. These findings are purposeful for physicians who would be able to foster more effective, specific upper airway treatment choices for patients with OSA. This study shows that UPPP significantly benefits patients with OSA, which decreases daytime drowsiness by allowing them to experience better nocturnal rest.
The findings could be considered an invalid reflection of reality considering the fact that the study was conducted in a sleep lab and out of the patients’ regular sleeping environment. By removing the patients from their usual sleeping environment, this can alter results due the possibility of comfortableness of sleeping in a new or different place. Limitations to the study were that only male patients were involved in the study because the number of female patients was to small to show any statistical significance (Hsu et al., 2007). The findings were coherent but it was often necessary to refer to the terminology index to understand their relationship to the images given in the article.
In regards to nursing practice, this information is valuable in the perioperative area as well as in the overweight population. The knowledge from this study greatly helps physicians and surgeons in devising more effectual, specific upper airway treatment options for patients with OSA (Hsu et al., 2007). Understanding OSA helps anesthesiologists and nursing staff in all phases of the perioperative care to ensure proper airway management. Patients could be advised to seek evaluation and treatment to improve their quality of life and avoid further health risks.
Friedman, M. (2009). Sleep apnea and snoring: Surgical and non-surgical therapy. Elsevier Health Sciences. Hsu, P., Tan, A., Tan, B., Gan, E., Chan, Y., Blair, R., & Lu, P. (2007). Uvulopalatopharyngoplasty outcome assessment with quantitative computer-assisted videoendoscopic airway analysis. Act Oto-Laryngologica, 127, 65-70. McDonald, J. H. (2009). Handbook of Biological Statistics (2nd ed.). Baltimore, Maryland: Sparky House Publishing.