Ova fecundity in Scottish Atlantic salmon Salmo salar: predictions, selective forces and causal mechanisms.

Ova fecundities of Scottish Atlantic salmon Salmo salar, predicted from log(10) regression of ova numbers and female fork length (L(F)), differed widely between upland and lowland stocks within the same river, whereas sea-age, river and year factors had insignificant effects on fecundity once L(F) was accounted for. For upland fish, the relationship between log(10)L(F) and log(10) ova mass (M(O)) was stable between two datasets collected 40 years apart. Although upland and lowland females both produced comparable log(10)M(O) (log(10)L(F))(-1), lowland females partitioned this into 45% more, but smaller ova, whereas upland females produced fewer, but larger, eggs. The possible causes and implications of this are discussed for evolutionary perspectives (lifetime production), population structure (local tributary v. large catchments; environmental effects), population dynamics and stability (density-dependent control mechanisms) and fisheries management (stock-recruitment; short and long-term stock sustainability).

Rapid traction for reduction of cervical spine dislocations.

There is still some controversy about the reduction of unilateral and bilateral facet dislocations in the cervical spine. We have reviewed the notes and radiographs of 210 such patients; reduction was attempted by manipulation under anaesthesia (MUA) in 91, and by rapid traction under sedation in 119, using weights up to 150 lb (68 kg). Our results suggest that early reduction in patients with neurological deficit gives the best chance of neurological recovery, that rapid traction is more often successful than MUA, and that traction is safer than MUA. We found that the use of heavy weights with close monitoring was safe and brought about reduction in an average time of 21 minutes. We recommend this technique for the reduction of all cervical facet dislocations.

Dysphagia in the patient with a tracheostomy: six cases of inappropriate cuff deflation or removal.

Patients with tracheostomy tubes have altered motor and sensory functions that may decrease their swallowing efficiency. Failure to recognize disorders in deglutition may result in dangerous complications including aspiration and death. Assessment of dysphagia is especially important in the patient transferred from the intensive care unit to the ward--where resources are less abundant. We present six cases in which cuff deflation or change of tracheostomy tube were undertaken without documented swallowing assessment. In these cases each patient was found to be aspirating and required the cuff to be reinflated, or a cuffed tube to be reinstated when assessed by the multidisciplinary team. Dysphagia management in the patient with a tracheostomy should be approached from a multidisciplinary point of view so that appropriate decisions can be made regarding changes in management and the decannulation process.

Upregulation of the esophago-UES relaxation response: a possible pathophysiological mechanism in suspected reflux laryngitis.

BACKGROUND: Inappropriate or excessive, non-swallow related, reflexive relaxation of the upper esophageal sphincter (UES) in response to esophageal distension may be the principal mechanism permitting retrograde trans-sphincteric flow during acid regurgitation. The neural pathways mediating reflexive UES relaxation in the human have received little attention. Patients with laryngitis demonstrate an increased acid reflux in the proximal esophagus. Such events, combined with an increased tendency for UES relaxation, might precipitate regurgitation into the pharynx. The aim was to determine whether the esophago-UES relaxation reflex induced by rapid esophageal distension is upregulated in patients with posterior laryngitis. METHODS: In 21 healthy volunteers and 14 patients with posterior laryngitis, UES responses to rapid air insufflation were examined. UES responses were monitored with perfused manometry catheter with a oval sleeve sensor. KEY RESULTS: The probability of triggering UES relaxation in response to the rapid esophageal air distension, for all volumes of insufflation, was higher in laryngitis (45%) than in health (17%). The minimum distension volume required to elicit an UES relaxation response was significantly lower in laryngitis patients when compared with controls. Patients who demonstrated a laryngoscopic response to a trial of omeprazole, were less likely to generate a distension-induced UES contractile response (5%) than patients who did not respond (23%). CONCLUSIONS & INFERENCES: The threshold for esophageal distension-induced UES relaxation is reduced in patients with laryngitis when compared with controls. This finding supports the hypothesis that in this population, a hypersensitive belch-like response may be one contributory mechanism of regurgitation when triggered by an abrupt spontaneous gastro-esophageal reflux event.

Predictors of outcome in an open label, therapeutic trial of high-dose omeprazole in laryngitis.

BACKGROUND: Gastroesophageal reflux is implicated in some cases of laryngitis. There are no established predictors of response to acid suppression therapy in suspected reflux laryngitis. AIM: In a population with laryngitis, the aim is to determine whether (a) omeprazole 20 mg tds (3 months) improves symptoms and laryngitis, and (b) the outcome in response to potent acid suppression can be predicted by esophageal and/or pharyngeal parameters during ambulatory pH monitoring or by other pretreatment variables. METHODS: From the 70 consecutive patients with laryngitis screened, 20 patients met the inclusion criteria (dysphonia >3 months; laryngoscopically demonstrated laryngitis); and 50 patients were excluded because of one or more criteria indicating alternative causes for laryngeal injury. The primary outcome measure was improvement of at least one level in a 4-point laryngitis grading at 3 months. Twenty-four-hour dual, pharyngo-esophageal pH monitoring was performed at baseline. Secondary outcomes (symptom questionnaire; computerized voice analysis) were measured at baseline, and at 6 and 12 wk. RESULTS: Response rates at 6 and 12 wk were 47% and 63%, respectively. GERD symptoms (heartburn (p= 0.03) and regurgitation (p= 0.0001)) improved. However, neither baseline GERD symptoms nor endoscopic findings predicted laryngoscopic or symptomatic response. Neither baseline laryngitis grade (p= 0.46) nor esophageal acid exposure on pH testing (p= 0.3) predicted outcome. Four of 20 patients demonstrated pharyngeal regurgitation on pH testing, all four of whom responded to potent acid suppression (p= 0.2). Computerized voice measures were not predictive of outcome, although fundamental frequency (Fo) was inversely related to baseline laryngoscopic grade. CONCLUSION: In a carefully defined population of patients with laryngitis (a) 63% have a laryngoscopic response to 3 months of potent acid suppression without significant improvement in laryngeal symptoms; (b) neither voice measures, esophageal acid exposure time, symptoms nor severity of laryngitis predict outcome; and (c) although numbers were small, all patients with a positive pharyngeal pH study responded to therapy and pharyngeal pH-metry may prove useful; (4) available evidence supports an empiric trial of high-dose proton pump inhibitors (PPI), for at least 12 wk, as the initial diagnostic step for suspected reflux laryngitis.