IS THERE A SPECIFIC LINKAGE BETWEEN OBSTRUCTIVE SLEEP APNEA SYNDROME AND GASTROESOPHAGEAL REFLUX DISEASE?

Obstructive sleep apnea syndrome (OSAS) is a common condition characterized by repetitive sleep‐induced collapse of the upper airways. It is associated with increased risk for hypertension, ischemic heart disease, cerebral stroke, and traffic accidents. In contrast, gastroesophageal reflux disease (GERD) is a very common disorder defined as various symptoms or esophageal mucosal damage generated by the abnormal reflux of gastric contents into the esophagus. Patients with OSAS have been reported to have a high prevalence of gastroesophageal reflux (GER) symptoms. The increase of transdiaphragmatic pressure in parallel with the large negative intrathoracic pressure produced during apnea events may directly lead to GER. In addition, some studies have demonstrated improvement in GERD with the application of continuous positive airway pressure, most consistently effective treatment for OSAS. However, GER dose not occur with every apnea. Moreover, the common conditions observed in patients with OSAS, including obesity or alcohol ingestion, are also predisposing factors for GER. A more recent investigation in over 1000 subjects failed to show a causal link between both diseases. Thus, the potential relationship between OSAS and GERD remains controversial. Inconsistencies in definitions of both diseases or sampling biases may contribute to the confusing results.     

The HGAR1 familial hypercholesterolemia pedigree

Data on 232 members of a single pedigree, descended from two pairs of original parents, were made available to the participants of Genetic Analysis Workshop 8 (GAW8). In addition to information concerning age and sex, measurements for 10 quantitative traits and genotypes at 22 polymorphic marker loci were also provided for a subset of 193 of these family members. © 1993 Wiley-Liss, Inc.     

Pediatric intracranial pressure monitoring in hypoxic and nonhypoxic brain injury

We reviewed the results of all pediatric patients undergoing intracranial pressure (ICP) monitoring in a 2-year period at our institution. The outcome of patients suffering hypoxia or ischemic injuries (HII) is compared to those suffering non-hypoxic or non-ischemic injuries (NHII). Thirty-four patients had ICP monitors placed during the study period. Inconplete patient information led to the exclusion of 5 patients. An additional 5 patients were excluded because no measures to control ICP were taken after the monitor was placed. Twenty-four patients required treatment for raised ICP (hyperventilation, 24; mannitol, 19; barbiturate coma, 6). Admission Glasgow Coma Score in patients suffering HII (median score 5) and NHII (median score 6) were not significantly different (Mann-Whitney U Test). Only 2 of 8 patients with HII were near-drowning vietims. The remaining 6 had HII from other causes (5 survivors of various forms of asphyxia and 1 of cardiac arrest). All 8 patients had poor outcomes (1 severely disabled; 7 died). The 16 patients with NHII had a variety of diagnoses (6 trauma, 5 encephalitis, 4 bacterial meningitis, 1 diabetic ketoacidosis). Among these, 6 had good outcomes and 10 poor outcomes (2 severely disabled, 2 vegetative, and 6 died). The difference in outcome between patients with NHII and HII is significant at P=0.059 (Fischer Exact test). Patients with NHII may benefit from ICP monitoring. Patients with HII from near-drowning and other causes did not appear to benefit from ICP monitoring and interventions directed at controlling ICP.     

Monitoring pressure ulcer healing in persons with disabilities.

Pressure ulcers are a high-risk, high-volume, and high-cost problem for persons with disabilities. This article describes four tools published in the literature and reports the validity, reliability, strengths, and limitations of each. These tools include the Pressure Ulcer Scale for Healing (PUSH), the Pressure Sore Status Tool (PSST), the Sussman Wound Healing Tool (SWHT), and the Sessing Scale. Rehabilitation nurses should use a consistent framework with accurate quantification to assess, document, and monitor changes in pressure ulcers over time. Such a measurement tool must prove valid for the disabled population in which the tool is used. This will enable healthcare providers to communicate more effectively and evaluate the therapeutic plan of care.     

Sutureless bowel anastomosis using Nd:YAG laser

Small bowel anastomoses were performed without sutures by using the Nd:YAG laser to produce welded enterotomies. Optimal energy levels for contact and noncontact laser were determined. Anastomoses produced using five target energy levels between 100 and 500 J were examined. Short-term anastomotic strength of these enterotomies was measured 1 min after the welding. Bursting pressure of the laser welded enterotomies was compared to the bursting pressure of traditional two-layer, inverting, interrupted sutured bowel anastomoses. The overall mean bursting pressure of non-contact-welded enterotomies was 50.6 mmHg. Optimal laser settings determined in this initial phase were then used to produce anastomoses in rabbits which are recovered postoperatively for 1 or 2 weeks in order to examine long-term viability and integrity of the anastomoses. All chronic rabbit preparations recovered without complication. The mean bursting pressure was 200 mmHg, not significantly different from that of uncut bowel or two-layer sutured anastomosis.     

EFFECT OF CROSS-FOSTERING ON NEONATAL SODIUM BALANCE AND ADULT BLOOD PRESSURE IN THE SPONTANEOUSLY HYPERTENSIVE RAT

1. The aim of the present study was to compare electrolyte handling in naturally reared neonatal spontaneously hypertensive rats (SHR) with those reared by a Wistar-Kyoto (WKY) rat foster mother (denoted SHRX), as cross-fostering SHR pups to a WKY rat dam lowers adult blood pressure in the SHR. 2. The electrolyte content of WKY rat and SHR dams’ milk was determined and electrolyte intake and urinary excretion rates were calculated in both naturally reared and cross-fostered WKY rat and SHR pups. 3. The milk sodium concentration fell in both strains (WKY rat: 31.8 ± 2.0 to 15.2 ± 1.2 mmol/L; SHR 31.9 ± 2.5 to 18.2 ± 1.6 mmol/L; P < 0.001), as did potassium (P < 0.001), over lactation, but there were no differences between strains. Calcium and magnesium concentrations increased (P< 0.001), although SHR dam's milk contained less calcium (P < 0.001) than that of WKY rat dams during the third week of lactation. 4. Spontaneously hypertensive rat pups ingested less milk (P<0.05) than WKY rat pups; therefore, their cumulative sodium intake over postnatal days 4–15 was significantly lower than that of WKY rat pups (WKY rat vs SHR: 84.4 ± 3.6 vs 59.7 ± 2.6 μmol/g bodyweight, respectively; P < 0.05) and fostered SHRX pups (77.7 ± 7.0 μmol/g bodyweight; P < 0.05). Potassium and magnesium intakes were comparable between SHR, WKY rat and SHRX pups, but SHR pups ingested significantly less calcium than either WKY rat pups (136.1 ± 6.4 vs 200.1 ± 9.5p, mol/g bodyweight, respectively; P<0.05) or SHRX pups (200.0 ± 18.0 μmol/g bodyweight; P<0.05). 5. These data show that the neonatal SHR experiences a period of sodium deficiency during the developmental stage when cross-fostering is effective in lowering blood pressure. This is consistent with the reported up-regulation of the renin-angiotensin system observed in SHR at this time and may have a long-term influence on blood pressure.     

THE EFFECT OF HYPERTENSIVE EPISODES AND CARDIAC HYPERTROPHY ON THE CANINE CARDIAC BAROREFLEX

1. Left ventricular (LV) hypertrophy has been implicated in the reduction of baroreflex sensitivity present in hypertension. The aim of the current study was to investigate the mean arterial pressure-heart rate reflex (MAP-HR) in a model which induced left ventricular hypertrophy but no sustained blood pressure elevation. 2. Five mongrel dogs were exposed to transient blood pressure elevation of between 20 and 30 mmHg, through hindlimb compression using a pneumatic pressure suit, for 7 h per day, 6 days per week for 6 weeks. Resting blood pressure was not altered by the 6 week hindlimb compression intervention. 3. Echocardiographically determined LV mass (mean ± s.e.m.) was 116.0 ± 7.4 g prior to hindlimb compression (baseline) and elevated to 125.4 ± 8.1 g (P= 0.003) after 6 weeks of compression. A reduction in the early (E) to late (A) transmitral diastolic flow ratio (E/A) from 1.80 ± 0.06 at baseline to 1.54 ± 0.09 (P = 0.037) after the 6 week intervention suggested that cardiac compliance was reduced. 4. The maximum gain of the MAP-HR reflex, studied using the ‘steady-state’ drug technique, when blood pressure was normal, showed a trend for reduction from 3.85 ± 0.43 beats/min per mmHg at baseline to 3.10 ± 0.45 beats/min per mmHg (P= 0.067) after 6 weeks of compression. This gain reduction became significant after β-adrenoceptor blockade with propranolol (3.13 ± 0.55 vs 2.32 ± 0.25 beats/min per mmHg; P= 0.039). Covariant analysis showed a significant inverse correlation between LV mass and maximum gain (r= 0.96; P<0.001) during the 6 week compression period. 5. The MAP-HR reflex changes in this model mimic those present in hypertension and implicate cardiac hypertrophy as one possible mediator.     

Large volume injection and infiltration system

Summary A system which can be used for injection or infiltration of large volumes of fluid is described. This consists of a syringe which fills automatically from a reservoir through an inlet/outlet valve.     

Continuous recording of urethral activity in healthy female volunteers

The pressure variations at the maximal urethral closure pressure (MUCP) were continuously recorded in healthy female volunteers by means of a two-point microtip transducer catheter for one hour. Before the investigation a normal voiding was assured objectively and bladder instability was excluded. All women showed pressure variations both at the MUCP and more distally. The pressure variations, from 3 to 66 cm H₂O, showed rhythmicity and three frequency ranges could be identified. Slow pressure waves with a frequency of one in eight to 19 minutes were observed. Relatively fast-pressure waves were observed (one every one to four minutes) and relatively fast-frequency pressure waves were observed (rate: one to eight per minute). The pressure variations of the urethra seem to be an aspect of normal urethral physiology possibly contributing to continence and urinary tract infection prevention.