The pediatric use of bilevel positive airway pressure therapy for obstructive sleep apnea syndrome: a retrospective review with analysis of respiratory parameters

The purpose of this study was objective documentation of clinical benefits of bilevel positive airway pressure in pediatric patients with obstructive sleep apnea. We performed a retrospective chart review and data collection/analysis in a suburban tertiary care children's hospital. The study consisted of 10 pediatric patients (age range: 3 to 18 years); 3 patients had craniofacial abnormalities, 1 patient had neuromuscular disease, and 6 patients were obese. Eleven-channel polysomnography and support with bilevel positive airway pressure were used. We measured obstructive sleep apnea indices, lowest oxygen saturation rate, and average breath lengths before and after bilevel positive airway pressure use. We found that the apnea index decreased from 19.7 +/- 26.46 to 0.82 +/- 1.01, the lowest oxygen saturation increased from 75.60% +/- 14.93% to 89.50% +/- 5.50%, and breath length increased from 3.22 +/- 0.95 to 3.68 +/- 0.82. Bilevel positive airway pressure may be considered as a treatment modality for pediatric patients with obstructive sleep apnea.     

Use of allogenic dermis for radial forearm free flap donor site coverage

OBJECTIVE: The radial forearm free flap has become the method of choice for reconstruction of head and neck defects following oncologic ablation. Harvesting of a radial forearm free flap leaves a donor site defect. This is most commonly closed with a split-thickness skin graft. Morbidity, most commonly owing to a lack of graft take over the tendons, can be quite high. Recently, an acellular matrix (Alloderm) has been advocated to decrease complications at the radial forearm donor site, as well as obviate taking a split-thickness skin graft from the thigh. MATERIAL AND METHODS: Tertiary referral academic centre. Retrospective chart review of 15 patients. Five patients received allogenic dermis, 10 patients received split-thickness skin grafting to the radial forearm donor site. RESULTS: Patients with allogenic dermis took between 12 and 16 weeks to heal completely. Patients undergoing split-thickness skin graft were completely healed within 4 to 6 weeks. Cosmesis was judged to be marginally better in the allogenic dermis group. Allogenic dermis placement had a greater impact on hand function owing to prolonged healing, whereas patients with split-thickness skin graft required wound care at the thigh for a 2- to 3-week period owing to the harvesting of the skin graft. CONCLUSIONS: Allogenic dermis may be a viable alternative to split-thickness skin grafting and radial forearm free flap donor sites. Prolonged healing with subsequent increased health care services use needs to be addressed.     

Preoperative fasting: old habits die hard

OVERVIEW: Prolonged preoperative fasting is a time-honored tradition. The typical order of "npo after midnight" (or no liquid or food after 12 am on the day of surgery) has been challenged in recent years-so much so that in 1999 the American Society of Anesthesiology (ASA) revised its practice guidelines for preoperative fasting in healthy patients undergoing elective procedures. The newer, more liberal recommendations, based on studies showing that pulmonary aspiration occurs only rarely as a complication of modern anesthesia, allow the consumption of clear liquids up to two hours before elective surgery, a light breakfast (tea and toast, for example) six hours before the procedure, and a heavier meal eight hours beforehand.There is a well-known lag between the dissemination and implementation of practice guidelines, so the authors sought to determine whether the publication of the revised ASA recommendations had changed preoperative fasting practices. They interviewed 155 patients in one hospital about their preoperative fasting, comparing instructed, actual, and ASA-recommended fasting durations for liquids and solids. Their findings demonstrate that the majority of patients continued to receive instructions of npo after midnight for both liquids and solids, whether they were scheduled for early or late surgery. On average, the patients fasted from liquids and solids for 12 and 14 hours, respectively, with some patients fasting as long as 20 hours from liquids and 37 hours from solids. These fasts were significantly longer than those recommended by the ASA, indicating that inappropriate preoperative fasting is an issue that demands attention.The authors conclude that more collaboration between nurses and physicians is needed to assure that fasting instructions are consistent with the ASA guidelines and that patients understand these directives.     

Practice environments that attract and retain nurses

Research shows that there is a direct correlation between the quality of nurses' work environments and the quality of client care. RNABC's newest policy statement, Nursing Practice Environments for Safe and Appropriate Care, identifies the key elements in an organization that are associated with improved client outcomes through attraction and retention of nurses.     

MP4, a new nonvasoactive PEG-Hb conjugate

BACKGROUND: Vasoconstriction has been an obstacle to clinical development of Hb-based O2 carriers. It is proposed that this limitation can be overcome by increasing molecular size and oxygen affinity. STUDY DESIGN AND METHODS: Surface-modified Hb (MP4) was designed, whose properties are consistent with the theory that cell-free Hb engages autoregulatory vasoconstrictive responses to Hb diffusion in the plasma space ("facilitated diffusion"). Human Hb was modified by reaction first with 2-iminothiolane to add sulfhydryl groups and then with monofunctional maleimide- activated 5-kDa PEG. RESULTS: MP4 was found to have a molecular weight of 90 kDa, a molecular radius increased relative to native Hb (9.3 +/- 1.4 vs. 3.2 nm), high oxygen affinity (p50 approximately 5-6 mmHg), and a Bohr effect approximately half that of native human Hb (-0.24Deltalogp50/DeltapH). At 4.2 g per dL in Ringer's lactate, its viscosity was 2.5 cP, and its oncotic pressure was 50 mmHg. The t50 of 14C-MP4 in rats was approximately 24 hours. No significant elevation in mean arterial pressure was observed. CONCLUSION: MP4 appears to be free of a pressor effect, a major limitation to the development of a safe and effective RBC substitutes in the past.     

Osteomyelitis of the temporomandibular joint

Osteomyelitis of the temporomandibular joint is very uncommon, and osteomyelitis as a result of Aspergillus niger infection has not previously been reported. A case report of skull base and condylar osteomyelitis is presented. Previously reported cases of temporomandibular joint osteomyelitis are reviewed, and management is discussed. Because of the significant morbidity possible with infections in this region, otolaryngologists should be familiar with the anatomy, diagnostic modalities, and therapeutic options. [Editorial comment: This unusual case presents unique aspects of the pathophysiology of osteomyelitis of the skull base.]     

Statistical analysis of QT interval as a function of changes in RR interval in the conscious dog

INTRODUCTION: The duration of cardiac ventricular depolarization and repolarization is represented as the QT interval. QT prolongation has been associated with the occurrence of arrhythmias. Both cardiovascular as well as noncardiovascular agents have caused QT prolongation and sudden death in humans. Changes in heart rate (HR) play a major, though not exclusive, role in QT variation. Considerable debate has centered on how to normalize QT for variations in HR (QTc). METHODS: The most common approaches use Bazett's (QTc = QT/(square root)RR) or Fridericia's (QTc = QT/(cube root)) formulas to fit the data and establish a single coefficient to analyze QT with respect to its relationship to RR, where RR= 60/HR. These single-coefficient models do not adequately describe the QT functional relationship with RR for the dog. Therefore, any calculation of QTc for the dog is misleading and can result in a false-positive indication or mask the potential hazards of a high QT. Other investigators have proposed multicoefficient exponential regression analyses to best fit the QT-RR relationship. RESULTS AND DISCUSSION: Data presented here from dogs under resting conditions and during pharmacological maneuvers (E-4031 or cisapride intravenous infusion) support the use of such a model. In order to fully characterize drug-induced changes in the QT-RR relationship, our approach includes a statistical comparison of the regression curves for an overall effect, and quantitates the incidence and magnitude of points exceeding the upper 95% confidence interval ('outliers') to assess the degree of heterogeneity of ventricular repolarization.