Climate change sensitivity index for Pacific salmon habitat in southeast Alaska.

Global climate change may become one of the most pressing challenges to Pacific Salmon conservation and management for southeast Alaska in the 21st Century. Predicted hydrologic change associated with climate change will likely challenge the ability of specific stocks to adapt to new flow regimes and resulting shifts in spawning and rearing habitats. Current research suggests egg-to-fry survival may be one of the most important freshwater limiting factors in Pacific Salmon's northern range due to more frequent flooding events predicted to scour eggs from mobile spawning substrates. A watershed-scale hydroclimatic sensitivity index was developed to map this hypothesis with an historical stream gauge station dataset and monthly multiple regression-based discharge models. The relative change from present to future watershed conditions predicted for the spawning and incubation period (September to March) was quantified using an ensemble global climate model average (ECHAM5, HadCM3, and CGCM3.1) and three global greenhouse gas emission scenarios (B1, A1B, and A2) projected to the year 2080. The models showed the region's diverse physiography and climatology resulted in a relatively predictable pattern of change: northern mainland and steeper, snow-fed mountainous watersheds exhibited the greatest increases in discharge, an earlier spring melt, and a transition into rain-fed hydrologic patterns. Predicted streamflow increases for all watersheds ranged from approximately 1-fold to 3-fold for the spawning and incubation period, with increased peak flows in the spring and fall. The hydroclimatic sensitivity index was then combined with an index of currently mapped salmon habitat and species diversity to develop a research and conservation priority matrix, highlighting potentially vulnerable to resilient high-value watersheds. The resulting matrix and observed trends are put forth as a framework to prioritize long-term monitoring plans, mitigation experiments, and finer-scale climate impact and adaptation studies.

Management of manifestations of epidermolysis bullosa.

PURPOSE OF REVIEW: Children with epidermolysis bullosa can present with disease(s) of the ears, nose, and throat, often related directly to the pathophysiology of their epidermolysis bullosa. Otolaryngologic diseases in children with epidermolysis bullosa have to be managed having a proper understanding of the diagnosis and pathophysiology of epidermolysis bullosa. The purpose of this review is to describe the current nomenclature and diagnostic algorithms for epidermolysis bullosa, and methods for the management of cutaneous and mucosal lesions. RECENT FINDINGS: Characterization of the gene defects leading to epidermolysis bullosa has allowed the utilization of immunofluorescent techniques as the primary method for epidermolysis bullosa diagnosis. Recognizing the difficulty in managing patients with epidermolysis bullosa, several multidisciplinary groups have developed guidelines using meta-analysis of the published literature, or expert panels. Though there are currently no effective treatment modalities for epidermolysis bullosa, techniques for gene and protein replacement show promising results for future use. SUMMARY: Currently, the management of cutaneous and mucosal disease in epidermolysis bullosa is based on the principles of prevention and wound care. Understanding the cause of epidermolysis bullosa types and subtypes, characteristics of skin and mucosal involvement, and prognosis will guide in the development of individualized treatment plans.

Use of historical logging patterns to identify disproportionately logged ecosystems within temperate rainforests of southeastern Alaska.

The forests of southeastern Alaska remain largely intact and contain a substantial proportion of Earth's remaining old-growth temperate rainforest. Nonetheless, industrial-scale logging has occurred since the 1950s within a relatively narrow range of forest types that has never been quantified at a regional scale. We analyzed historical patterns of logging from 1954 through 2004 and compared the relative rates of change among forest types, landform associations, and biogeographic provinces. We found a consistent pattern of disproportionate logging at multiple scales, including large-tree stands and landscapes with contiguous productive old-growth forests. The highest rates of change were among landform associations and biogeographic provinces that originally contained the largest concentrations of productive old growth (i.e., timber volume >46.6 m³/ha). Although only 11.9% of productive old-growth forests have been logged region wide, large-tree stands have been reduced by at least 28.1%, karst forests by 37%, and landscapes with the highest volume of contiguous old growth by 66.5%. Within some island biogeographic provinces, loss of rare forest types may place local viability of species dependent on old growth at risk of extirpation. Examination of historical patterns of change among ecological forest types can facilitate planning for conservation of biodiversity and sustainable use of forest resources.

Single-stage and multistage pediatric laryngotracheal reconstruction.

Acquired pediatric laryngotracheal stenosis almost always results from prolonged intubation for prematurity. An understanding of the process by which this occurs helps in prevention and treatment. Before deciding to perform cartilage augmentation procedures, more limited techniques such as medical therapy or endoscopic surgery need to be considered. Careful assessment of the patient and the stenosis aid the decision-making process for the right operation at the right time. Despite this assessment, patients with a severe or complete stenosis have a poorer prognosis, and cricotracheal resection may be a better option.

Cidofovir: to use or not to use?

PURPOSE OF REVIEW: Cidofovir is an antiviral agent that has been used increasingly in the last decade as an adjuvant therapy for recurrent respiratory papillomatosis. It has been used in patients with moderate to severe recurrent respiratory papillomatosis requiring frequent surgical intervention or if there is evidence of distal spread. Intralesional administration after surgical debulking delivers the medication directly to the site of disease and is thought to have fewer systemic side effects than intravenous infusion. This review examines recent publications for evidence of safety and efficacy. RECENT FINDINGS: Despite its growing popularity, the potential risks related to cidofovir use in recurrent respiratory papillomatosis have not been well documented. It is known to be nephrotoxic when administered intravenously and there remains concern that cidofovir has carcinogenic potential based on animal studies (mammary adenocarcinoma in rats). A review of the literature reveals no randomized controlled trials, one case-control study, multiple case series and case reports only. Study populations are small, however complete response rates have consistently been reported in approximately 60%. SUMMARY: Based on current opinion and research, it is likely that intralesional cidofovir will continue to have a role in the management of moderate to severe recurrent respiratory papillomatosis. Further studies are required to assess long-term outcomes.

Refractory choanal atresia: what makes a child susceptible? The great Ormond Street Hospital experience.

OBJECTIVE: An outcome analysis of factors that predispose patients to require multiple surgical procedures for choanal atresia repair. DESIGN: Retrospective case note review of choanal atresia patients identified from a prospectively collected database at Great Ormond Street Hospital for Children, London, between 1992 and 2005. SETTING: Specialist centre in pediatric otolaryngology. METHODS: All patients underwent atresia correction by a transnasal approach under endoscopic guidance using a 120 degrees Hopkins rod telescope to visualize the posterior choanae from the nasopharynx. The atretic plate was first perforated using urethral sounds. The posterior choanal opening was subsequently enlarged using the microdebrider drill. Portex endotracheal tubes were used as stents in selected cases. RESULTS: Twenty children (9 male, 11 female) were identified who underwent multiple surgical procedures for restenosis following choanal atresia repair during the study period. The number of procedures per patient ranged from 6 to 42. Approximately half of the patients had other associated major anomalies. CONCLUSIONS: Following primary endoscopic transnasal repair, 9.8% of the patients were considered to have refractory choanal atresia, requiring six or more surgical procedures. Male gender, bilateral disease, associated congenital anomalies, low birth weight, and small stent size are potential risk factors for restenosis of choanal atresia. There was no obvious relationship between the duration of stent placement and restenosis.

Safe reliable atraumatic replacement of misplaced paediatric tracheostomy tubes.

OBJECTIVE: Displacement of tracheostomy tubes, especially soon after insertion has a high morbidity and mortality rate. We present a safe atraumatic reliable method of tracheostomy tube replacement. SETTING: Tertiary paediatric centre. MATERIALS AND METHODS: The method involves using a suction catheter placed in the trachea. Its position can be confirmed by suctioning tracheal secretions. The catheter can be used to employ the Seldinger technique for replacement of the tracheostomy tube and can be used to jet ventilate the patient if there is failure to site a tube. This buys time while a surgical airway is placed. We also outline the minimum contents of the emergency box, which should be carried at all times by the carers of a child with a tracheostomy. CONCLUSIONS: Use of a suction catheter is a safe reliable atraumatic way of replacing a tracheostomy tube.

Successful treatment of laryngeal stenosis in laryngo-onycho-cutaneous syndrome with topical mitomycin C.

Laryngo-onycho-cutaneous syndrome is a very rare entity found in Punjabi families. It affects the skin, nails, and larynx. Laryngeal involvement may cause lethal airway obstruction, and has in the past proved very difficult to treat. Mitomycin C is an antibiotic that acts as an alkylating agent, inhibiting DNA synthesis. It reduces fibroblast proliferation, and has previously been used to treat choanal atresia and laryngeal stenosis. We report an 18-year-old man with complete transglottic laryngeal stenosis secondary to laryngo-onycho-cutaneous syndrome. An airway was established by dissection with a bougie and sickle knife, and was initially maintained by the upper limb of a Montgomery T-tube. Laryngeal granulation tissue present on removal of the T-tube was treated with topical mitomycin C (2 mg/mL) applied for 4 minutes on two occasions with an interval of 1 month. A year later, the airway remained patent, with no granulation tissue.

The changing indications for paediatric tracheostomy.

OBJECTIVE: To investigate whether the incidence and indications for paediatric tracheostomy in this unit have changed over recent years. METHODS: All paediatric tracheostomies performed between 1993 and 2001 were identified from our departmental database. The indications for these were ascertained by retrospective case note review. RESULTS: Over the 9-year period studied 362 tracheostomies were performed, the number increased slightly between the first and second half of the period, with peaks in 1997 and 1999. The commonest indication was prolonged ventilation due to neuromuscular or respiratory problems. CONCLUSIONS: This large series shows that the increase in frequency of paediatric tracheostomy performed in this unit over the past decade has been due to conditions such as subglottic and tracheal stenosis, respiratory papillomatosis, caustic alkali ingestion and craniofacial syndromes. Conditions in which tracheostomy are now less common are subglottic haemangioma and laryngeal clefts. Prolonged ventilation remains the commonest indication overall.

The effect of aryepiglottoplasty for laryngomalacia on gastro-oesophageal reflux.

OBJECTIVE: to investigate whether relief of airway obstruction in laryngomalacia by aryepiglottoplasty affects gastro-oesophageal reflux. METHODS: a prospective study of consecutive infants and children with suspected laryngomalacia. Gastro-oesophageal reflux was measured before and after diagnostic microlaryngobronchoscopy and aryepiglottoplasty. RESULTS: of the six cases who underwent aryepiglottoplasty and completed the study, three had significant pre-operative reflux according to age. In this group the reflux improved significantly after aryepiglottoplasty. In the other three cases, reflux was not age-significant pre-operatively nor did it change significantly post-operatively. CONCLUSIONS: when partial airway obstruction due to laryngomalacia co-exists with gastro-oesophageal reflux, treatment of the airway problem improves respiratory symptoms in all cases and reduces gastro-oesophageal reflux in patients with age-significant reflux. This suggests that there are two clinical groups, those with severe, age-significant reflux, possibly caused by airway obstruction, whose gastro-oesophageal reflux benefits from aryepiglottoplasty; and those whose reflux is physiological and not influenced by aryepiglottoplasty. Therefore aryepiglottoplasty can be expected to reduce gastro-oesophageal reflux in those infants with laryngomalacia who have age-significant reflux.

Tuberculous mastoiditis: when is surgery indicated?

Mycobacterium tuberculosis is a rare cause of mastoiditis, but diagnosis is often delayed, with potentially serious results. We present the case of a 7-year-old child who failed to improve even once the diagnosis was made and appropriate medical treatment initiated. At mastoidectomy, a bony sequestrum was found which had not been evident on CT scanning. We review the diagnosis and management of this condition and suggest that failure to respond to drug therapy even in the absence of demonstrable complications be added to the list of indications for surgical intervention.

A review of the current management of infantile subglottic haemangioma, including a comparison of CO(2) laser therapy versus tracheostomy.

OBJECTIVES: We reassessed the current practice and treatment options used in the management of subglottic haemangiomas (SGHs), including the place for open submucosal surgical excision, and have compared the results of different therapeutic modalities used for SGHs. METHODS: The two studies were conducted as separate exercises; (1) a retrospective review of 36 patients collected over a recent 8-year period to assess the current practice and treatment options in use; (2) a retrospective comparative study of a previous cohort of 51 patients with SGHs treated in one of four groups: (a) tracheostomy alone, (b) tracheostomy and CO(2) laser, (c) systemic steroids and CO(2) laser (no tracheostomy) and (d) intralesional steroid injection, CO(2) laser therapy, or both, followed by intubation. RESULTS: Systemic steroids were the most commonly used modality of treatment. Resolution of the SGH was achieved in 89% of cases at a mean follow up duration of 34 months. However, tracheostomy was required in 58% of cases, with a mean time from diagnosis to decannulation of 30 months. The time to resolution of SGHs does not appear to be reduced by laser therapy compared with treatment by tracheostomy alone. Intralesional steroid injection or laser therapy together with intubation was associated with avoidance of a tracheostomy in 66% of cases. Single-stage open surgical excision in two cases resulted in successful resolution of the SGH and discharge after a mean follow up period of 3 months. CONCLUSIONS: Despite the more widespread use of steroids and other treatment modalities, the requirement for tracheostomy has remained unchanged over the last 20 years. The use of laser therapy does not appear to confer any additional therapeutic benefit over and above tracheostomy alone in bringing about resolution of SGHs. Systemic steroids may reduce the size of the haemangioma but are associated with multiple adverse effects. The decision to use the above techniques must, therefore, be made in the light of these observations. Our early experience of single-stage excision suggests that this technique represents an exciting and promising surgical alternative, and its more widespread adoption may be the only way of further improving the outcome of patients with SGHs.