Airway surface pH in subjects with cystic fibrosis.

The cystic fibrosis (CF) transmembrane conductance regulator protein can transport bicarbonate and may therefore regulate airway surface (AS) pH. Disturbances of AS pH could contribute to the pathophysiology of CF lung disease. Five studies were carried out including the following: study 1) nasal pH measurements were made in 25 CF and 10 non-CF adults using an antimony pH probe. Mean nasal pH was significantly lower in the CF group. Nasal potential difference may have been a confounding factor; study 2) in a fresh cohort of CF and non-CF subjects, no significant difference was found between the two groups using a gold pH probe; study 3) simultaneous nasal pH measurements were made in 15 CF and 15 non-CF adults using both probes. In the CF group, there was a trend for the antimony probe to read lower than the gold probe. In the non-CF group, the antimony probe read higher. The pH difference noted in study 1 related to technical factors; study 4) the effect of acute changes in serum acid/base balance on nasal pH was assessed in five non-CF adults. Nasal pH was not altered by either acute respiratory acidosis or alkalosis; study 5) nasal and lower airway pH was measured in five CF and six non-CF children. No difference was found between the groups. There was a correlation between nasal and lower airway pH. The authors conclude that airway surface pH does not differ between cystic fibrosis and noncystic fibrosis subjects and therefore, cystic fibrosis transmembrane conductance regulator may not play a major role in airway surface pH in vivo.     

Platelet alpha granule secretion in cerebral ischemia: effect of short and long term low dose aspirin treatment

The effect of short and long-term therapy with aspirin (50 mg/day) on platelet alpha granule secretion was studied in 11 healthy controls and 57 patients suffering from transient cerebral ischemic attacks (TIA) with and without accompanying diabetes and hypertension. Plasma levels of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF 4) were measured as indicators of platelet alpha granule secretion. beta-TG and PF 4 levels were increased following cerebral ischemia. Aspirin treatment failed to suppress plasma levels of both proteins when measured a month and then a year after initiation of treatment. Therefore, these proteins may be poor indicators of platelet inhibition by aspirin.     

Systemic-pulmonary polytetrafluoroethylene shunts in palliative operations for congenital heart disease. Revival of the central shunt

The concept of central shunting in smaller children with the Waterston shunt was initially well accepted. It has been abandoned because of the difficult estimation of lumen size, preferential flow to the right side, and difficulty in the take-down of the shunt. We have replaced the Waterston shunt with a short segment of polytetrafluoroethylene between the ascending aorta and the main pulmonary artery. From January 1979 to December 1986, 190 shunt operations were performed in 157 patients, with the use of 26 classic Blalock-Taussig shunts (13.7%), six Waterston shunts (3.1%), nine Glenn shunts (4.7%), 80 central aortopulmonary polytetrafluoroethylene shunts (42.2%), and 69 modified Blalock-Taussig shunts (36.3%). Polytetrafluoroethylene grafts were used for 149 of the 190 (78.4%) shunts. Overall mortality was 15.2%, with nine early deaths (4.7%) and 20 late deaths (10.5%). Deaths were due to the complex nature of the congenital anomaly or definitive surgical repair. The patients weighed from 1.6 to 48 kg and ages ranged from 1 day to 22 years. We have modified our technique so that (1) graft length is less than 0.5 cm and both ends are beveled, (2) the aortotomy is fashioned with a punch, (3) the center of the polytetrafluoroethylene graft is never clamped, (4) heparin is given during the construction of the shunt, and (5) aspirin (10 mg/kg/day) is administered daily. Patency ranges from 1 to 4 years. We conclude that the polytetrafluoroethylene shunt provides excellent palliation and that the central shunt, in the smaller child and infant, offers the benefits of shunting without distortion of the peripheral pulmonary arteries.     

Anesthesia and/or Sedation for Pulsed Dye Laser Therapy

One of the most exciting developments in pediatric dermatology has been the use of the flashlamp-pumped, 585-nm, pulsed dye laser for treatment of vascular birthmarks. In many cases the results are miraculous. The increase in self-esteem and happiness of many children and adolescents has been overwhelming; for some, depression has been lifted, stuttering has ceased, social involvement has increased, and antidepressants have been discontinued. There are many success stories to tell.
Despite the remarkable effects of the pulsed dye laser and the medical and psychosocial indications for its use, the issue of pain control remains significant. We have no perfect outpatient pediatric anesthetic. Most methods carry either some risk or, if not hazardous, often are not very effective for controlling pain. Needless to say, a diversity of opinions exist on how to manage discomfort from this treatment modality. Therefore, we thought it would be useful to share the experiences and opinions of several dermatologists who have extensive experience with the pulsed dye laser.     

Correlation and comparison of body mass index on hemodynamics in hypertensive and normotensive patients undergoing intravenous sedation.

PURPOSE: The purpose of this project was to retrospectively compare and correlate body mass index (BMI) and hemodynamics in hypertensive and normotensive patients undergoing intravenous sedation for dentoalveolar surgery. PATIENTS AND METHODS: A retrospective chart analysis of 263 consecutive male patients undergoing intravenous (IV) sedation for dentoalveolar surgery was divided into 5 BMI groups: underweight, normal weight, overweight, obese, extremely obese. Data recorded were noninvasive baseline and intraoperative hemodynamic measurements at 5-minute intervals for systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse pressure (PP), and pulse (P). Statistical analysis of mean values between groups was carried out using multivariate linear regression analysis, Pearson's correlation coefficient, and Student's t test and found significant for P < .05. RESULTS: Average hemodynamic values for normotensive patients were significantly lower for all groups except for pulse in the normal group, pulse in the obese group, and DBP in the extremely obese group. For normotensive patients, there were statistically significant strong positive correlation for elevated BMI and increased baseline changes in SBP and PP. For the hypertensive group, there was a statistically significant moderate positive correlation for elevated BMI and increased baseline changes in PP and statistically significant strong positive correlation for baseline changes in MAP. Baseline changes were significant for greater increases in SBP and decreases in DBP and MAP in the underweight hypertensive group. Significant increases from baseline in the normotensive group were for PP in the normal BMI group and for pulse in the obese group. All baseline changes, with the exception of normotensive underweight SBP (+26.7%) and hypertensive PP (+23.9%), were within +/-20% of baseline (range, -12.2% to +17.4%). CONCLUSION: In general, normotensive patients in this study had lower average hemodynamic values than hypertensive patients in all BMI groups. Great variability was seen in baseline changes for all BMI groups, but a substantial majority of changes were within +/-20% of baseline. There were statistically significant moderate and positive correlations in BMI for changes from baseline for several hemodynamic measurements. Intravenous sedation for oral and maxillofacial surgery procedures maintains a stable hemodynamic state in hypertensive and normotensive patients regardless of BMI.