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Introduction: Red cabin lighting is often used for nighttime patient transports in helicopters. This study was conducted to determine if red lighting results in impairment of color-dependent tasks., Methods: An emergency medical services pilot adjusted red lighting in a BO-105 cabin to maximum acceptable intensity. Thirteen emergency room residents were shown positive and negative CO2 detectors and skin-colored and cyan-tinted rubber masks; percentages of correctly identified masks and detectors were noted. Subjects also read drug name and amount from 12 medication labels. Wilcoxon analysis (p = 0.05) was used to compare label reading accuracy between two groups: control (black/white lettering/background) and red (red lettering or background)., Results: Percentages of accurately identified masks and detectors in the red light setting were as follows: normal mask 61.5%, cyanotic mask 30.8%, negative and positive CO2 detectors 46.2%. Ability to correctly read medication labeling was significantly (p = 0.003) greater in control (76.9 +/- 10.9%) as compared to red groups (16.3 +/- 13.4%)., Conclusion: Red cabin lighting appears to impair performance of certain critical tasks requiring color discernment. Consideration of this by medical crews working under red light conditions could reduce risk for patient-care errors.

Previous research at the Division of Air Medical Services at East Carolina University School of Medicine has demonstrated impairment of chest compression efficacy in the setting of an airborne BO-105 helicopter. This study was undertaken to determine whether in-flight compression efficacy could be improved with utilization of a pressure-sensing monitor providing real-time feedback during cardiopulmonary resuscitation (CPR). Ten flight nurses each performed two minutes of in-flight chest compressions on a mannequin that electronically assessed compression depth and hand placement. The session was then repeated using the pressure-sensing device. The mean proportion of correct compressions (95.7 +/- 3.2%) achieved with utilization of the pressure-sensing monitor was significantly higher (P < .01) than the corresponding proportion for the control group (33.4 +/- 12.1%). This study demonstrated that the difficulties of performing effective in-flight chest compressions are largely overcome with utilization of a pressure-sensing device providing real-time feedback on compression efficacy.

To evaluate the effects of verapamil intoxication and glucagon treatment on blood glucose levels in an intact canine model, 15 mg/kg verapamil was administered intravenously over a 30-minute period to mongrel dogs under pentobarbital anesthesia. Animals in the experimental group subsequently were administered 2.5 mg glucagon followed by an infusion of 2.5 mg per hour; control group animals were administered an equal volume of saline. Blood glucose was assessed before verapamil administration (baseline), and at 10 minutes (time 10) and 60 minutes (time 60) after completion of the verapamil infusion. Glucose values were compared between control and experimental groups using Dunnett's method (P = .05). At baseline, no animals were hyperglycemic and there was no difference in glucose levels. Animals in both groups became hyperglycemic after verapamil infusion. At time 10, the experimental group had significantly higher glucose levels (265 +/- 17.1 mg/dL) than the control group (209 +/- 18.3 mg/dL). By time 60, there was no significant difference between glucose values in the control (262 +/- 31.4) and experimental (246 +/- 24.8) groups. It was concluded that verapamil intoxication consistently resulted in hyperglycemia in this model. Glucagon therapy was associated with an early but nonsustained exacerbation of verapamil-induced hyperglycemia.

Background: Several factors have been identified which improve nebulised aerosol delivery in vitro. One of these is the addition of a spacer to the ventilator circuit which improves aerosol delivery from a jet nebuliser to a model lung by approximately 30%. The current study was designed to demonstrate whether similar improvements could be demonstrated in vivo., Methods: Ten patients (seven men) were studied during mechanical ventilation (Siemens Servo 900C) after open heart surgery. Aerosol was delivered using a Siemens Servo 945 nebuliser system (high setting) driving a System 22 Acorn jet nebuliser (Medic-Aid) containing 3 ml technetium-99m labelled human serum albumin (99mTc-HSA (50 micrograms); activity in the first nebulisation, 90 MBq; in the second nebulisation, 185 MBq). Central and peripheral lung aerosol deposition and the time to complete deposition were measured using a gamma camera and compared when the nebuliser was connected to the inspiratory limb using a simple T-piece or a 600 ml spacer., Results: The addition of the spacer increased total lung deposition (mean (SD) percentage initial nebuliser activity) from 2.2 (0.7)% to 3 (0.8)%. There was no difference in the time required to complete nebulisation (18.2 min v 18.3 min respectively for T-piece and spacer) or in the retention of activity in the nebuliser (46.2% v 47.1% respectively)., Conclusions: The combination of a spacer with a jet nebuliser increased lung deposition by 36% in mechanically ventilated patients and is a simple way of increasing drug deposition or reducing the amount of an expensive drug required for nebulisation.

Field trials were conducted during 1986, 1988, 1989, and 1991 to compare the effects of 1,3-dichloropropene, fenamiphos, and carbofuran on yield and quality of chile peppers (Capsicum annuum) in soil infested with Meloidogyne incognita. When compared with untreated plots, numbers of M. incognita juveniles recovered from soil 60 and(or) 90 days after chile pepper emergence were reduced (P = 0.05) following 1,3-D treatment every year except 1986. Nematode numbers were also reduced (P = 0.05) by fenamiphos in 1989. Chile pepper yields were significantly higher than those in untreated control plots (P = 0.05) all 4 years in plots treated with 1,3-D and in 1989 in plots treated with fenamiphos. Use of carbofuran did not significantly reduce nematode numbers or enhance yields in these experiments. Green chile pepper fruit quality was enhanced (P = 0.05) following 1,3-D treatments in 1988 and 1989 but was unaffected by fenamiphos or carbofuran application. Increasing placement depth of 1,3-D from 28 to 48 cm increased (P = 0.05) red chile pepper yield compared with that obtained with conventional placement in 1988 only, and did not affect green chile pepper yield.

Recent demonstration of the dangers of hyperglycemia in the setting of cerebral hypoperfusion has resulted in recommendations to abandon the long-standing practice of empiric administration of dextrose to patients with altered mental status. Patients receiving basic cardiopulmonary resuscitation (CPR) have been identified as being at particular risk from inappropriate administration of dextrose. We conducted a prospective trial to determine whether the blood glucose of 50 patients receiving CPR could be accurately assessed using a portable rapid-reagent device in the emergency department (ED). We analyzed both capillary and venous blood samples in the rapid-reagent system, using laboratory analysis of venous blood to define the patient's true blood glucose level. Capillary blood analysis identified 8 patients as hypoglycemic; only 3 of these patients were truly hypoglycemic, and 2 patients identified as hypoglycemic by fingerstick were actually hyperglycemic on laboratory analysis. The only instance in which a patient was classified differently by venous rapid-reagent and laboratory analysis occurred when a patient assessed as normoglycemic (169 mg/dL) by the laboratory had a venous rapid-reagent glucose reading of 182 mg/dL (hyperglycemic). We recommend that venous (rather than capillary) blood be used to analyze blood glucose in all patients receiving CPR before dextrose administration is considered.

Study Objective: To compare the effectiveness of i.v. and PR prochlorperazine for treatment of acute benign vascular or tension headache., Design: Prospective, randomized, double-blind trial., Setting: University emergency department with 50,000 annual census., Participants: Forty-five adult patients enrolled on 46 visits., Interventions: Patients received 10 mg prochlorperazine i.v. and placebo suppository or 25 mg prochlorperazine PR and placebo injection. Pain assessment was made using a 10-cm visual-analog scale; scores were analyzed using Wilcoxon/Kruskal-Wallis rank-sum tests (alpha of .01)., Results: Mean 60-minute pain scores for i.v. and PR groups were 0.6 and 3.5, respectively (P = .0002). Two patients (8.7%) in the i.v. group and six patients (26.1%) in the PR group required rescue analgesia (P = .12)., Conclusion: i.v. prochlorperazine appears to provide more effective relief than PR prochlorperazine for benign vascular or tension headaches.

The complaint of headache is frequently encountered in the emergency department, but most patients with cephalalgia have a benign etiology for their pain. At least 90% of patients presenting with headache are diagnosed as suffering from benign vascular or muscle-tension (for example, migraine, tension, or mixed-type) headache. There is no consensus on the ideal therapeutic approach to these patients. Classically utilized narcotic therapy suffers from problems with efficacy, relapse, and potential for abuse and addiction. However, other agents have successively proved to be imperfect as well, despite the many therapeutic approaches that have been suggested in the medical literature. While no one drug has emerged as clearly superior for treatment of acute benign headache, recent investigations have clarified the role of certain therapies. This review is intended to familiarize emergency physicians with the latest information on most recommended therapeutic approaches to the patient with headache.

Introduction: Patients transported by helicopter often require advanced airway management. The purpose of this study was to determine whether or not the in-flight environment of air medical transport in a BO-105 helicopter impairs the ability of flight nurses to perform oral endotracheal intubation., Setting: The study was conducted in an MBB BO-105 helicopter., Methods: Flight nurses performed three manikin intubations in each of the two study environments: on an emergency department stretcher and in-flight in the BO-105 helicopter., Results: The mean time required for in-flight intubation (25.9 +/- 10.9 seconds) was significantly longer than the corresponding time (13.2 +/- 2.8 seconds) required for intubation in the control setting (ANOVA, F = 38.7, p < .001). All intubations performed in the control setting were placed correctly in the trachea; there were two (6.7%) esophageal intubations in the in-flight setting. The difference in appropriate endotracheal intubation between the two settings was not significant (chi 2 = 0.3; p > 0.05)., Conclusion: Oral endotracheal intubation in the in-flight setting of the BO-105 helicopter takes approximately twice as long as intubation in a ground setting. The results support pre-flight intubation of patients who appear likely to require urgent intubation during air medical transport in the BO-105 helicopter.

Epidural empyema is an unusual cause of headache that may be encountered in the emergency department. The collection of suppurative fluid usually results from local spread of sinusitis, although many other predisposing factors have also been described. Patients with epidural empyema usually present with nonspecific cephalalgia that may be accompanied by fever and leukocytosis but is unlikely to be associated with focal neurological findings. The case of an adolescent who presented to our emergency department twice in 6 days with persistent headache is reported; cranial computed tomography performed on the second visit demonstrated bilateral epidural empyema. This entity is uncommon, but may certainly be encountered by the emergency physician.

Critically ill patients are often transported by air ambulances. Although these patients are likely to require cardiopulmonary resuscitation (CPR) during transport, the effects of the air medical transport environment on CPR efficacy have never been studied. A manikin model was used to assess the ability of flight nurses to perform effective chest compressions while in flight and when stationery on the helipad. The results demonstrate that flight nurses were able to perform chest compressions as effectively in the in-flight setting as in the stationary setting. Chest c compressions performed in the BK-117 helicopter were as effective as those performed in the control environment, but compressions performed in the BO-105 were significantly less effective than controls. In conclusion, in a manikin model, chest compressions are substandard in the BO-105 helicopter because of the limited space available in the aircraft.

Introduction: The purpose of this study was to compare the outcome of interhospital transported cardiac patients for whom bias in selecting transport mode was removed due to helicopter unavailability., Methods: Patients with the diagnosis of unstable angina or myocardial infarction who underwent transport by ground only because helicopter transport was not available, were compared to patients transported by helicopter. Patients were matched by gender and referring hospital. Ninety-six patients were studied and both groups were comparable in age, diagnosis, Killip classification, treatment with thrombolytics and post-transport procedures., Results: There were no statistically significant differences between the groups for mean ICU days (5.3 air vs. 3.5 ground) and mean hospital days (9.9 vs. 8.2, respectively). No differences were detected in the proportions of deaths within 72 hours of arriving at the receiving institution (1/48 air vs. 0/48 ground), but air transportation was associated with more total deaths (9/48 vs. 1/48, respectively)., Conclusion: It appears that the interhospital transport of cardiac patients by air offers no outcome advantage over ground transport.

We report the case of a 23-year-old male who presented to the emergency department with severe upper airway obstruction resulting from infection of the palatine tonsils. Manifestations of tonsillar infection and airway obstruction included hoarseness and extreme difficulty breathing, severe sore throat and inability to swallow liquids or solids. Urgent otolaryngologic consultation was obtained, and the patient was taken directly to the operating suite for nasotracheal intubation with tracheostomy standby. The patient was maintained on broad-spectrum antibiotics and was discharged after a hospital course complicated by pulmonary oedema, tracheitis and difficulty weaning from the ventilator, requiring temporary tracheostomy. The Monospot test was negative for infection with the Epstein-Barr virus (EBV). We could find no previously reported cases of adults with severe palatine tonsillar-induced airway obstruction which was not due to infection with EBV (mononucleosis). The airway management of obstruction due to palatine tonsillar hypertrophy is discussed.

Introduction: The advent of air medical transport has pushed the delivery of critical care medicine into the prehospital arena. As a result, a wide variety of pharmacologic agents must be available in the air medical setting., Purpose: The purpose of this study was to conduct a retrospective review of drugs used during air medical transport to allow a streamlining of the air ambulance formulary., Methods: All flights completed since the inception of the study's helicopter air ambulance program in 1985 through September 1991 were analyzed to determine which medications were used in flight. Drugs were counted if they were administered while in flight for either a scene or interhospital transport., Results: Review of 2,694 flights showed that 45 individual drugs had been routinely carried during the study period. Many of these agents were administered fewer than five times during the six years, and 10 drugs were not used at all., Conclusion: As a result of this investigation, the formulary for our air medical transport service was modified. The authors recommend similar critical audits of drugs carried in flight be performed by other air ambulance services.

Sodium bicarbonate is an extremely well-known agent that historically has been used for a variety of medical conditions. Despite the widespread use of oral bicarbonate, little documented toxicity has occurred, and the emergency medicine literature contains no reports of toxicity caused by the ingestion of baking soda. Risks of acute and chronic oral bicarbonate ingestion include metabolic alkalosis, hypernatremia, hypertension, gastric rupture, hyporeninemia, hypokalemia, hypochloremia, intravascular volume depletion, and urinary alkalinization. Abrupt cessation of chronic excessive bicarbonate ingestion may result in hyperkalemia, hypoaldosteronism, volume contraction, and disruption of calcium and phosphorus metabolism. The case of a patient with three hospital admissions in 4 months, all the result of excessive oral intake of bicarbonate for symptomatic relief of dyspepsia is reported. Evaluation and treatment of patients with acute bicarbonate ingestion is discussed.

Introduction: In critically ill patients (e.g., trauma victims) prevention of hypothermia is an important goal. Infusion of warm fluids has been addressed in the hospital setting, but not in the air medical transport setting., Purpose: The purpose of this study was to test the efficacy of an intravenous (IV) fluid warming device that is well-suited for the air medical transport environment., Method: The warmer studied was used with IV fluid heated to approximately 38 degrees C (100 degrees F) and evaluated in environmental temperatures of -16 degrees C (3 degrees F), 2 degrees C (36 degrees F), and 22 degrees C (72 degrees F). The warmer group was compared to a control group of similarly treated IV fluids without a warming device. Temperatures were measured at baseline, 15, 30 and 60 minutes., Results: The 30- and 60-minute fluid temperatures were higher in the warmer than in the control group for all three environmental temperature settings. At 15 minutes, fluid temperatures were higher in the warmer group for the 2 degrees C and -16 degrees C, but not the 22 degrees C, environments. There was no significant drop in temperature in the warmer group in the 22 degrees C and 2 degrees C settings, but a decrease was noted in the -16 degrees C environment. There was a significant drop in the control group at all temperatures tested., Conclusion: The IV fluid warmer tested effectively maintains the temperature of warmed IV fluids in temperatures above 2 degrees C. At -16 degrees C there was significant heat loss, but the loss was significantly less when compared to the control group.

Introduction: Patients transported by air ambulance are often critically ill and, thus, have a relatively high likelihood of requiring advanced life support (ALS) measures during transport. Despite this fact, the ability of the air medical crew to perform ALS interventions efficiently while in flight has not been investigated., Setting: The study was conducted with BO 105 and BK 117 helicopters and a ground transport unit at a university hospital-based air ambulance service., Methods: Ten flight nurses were timed performing various ALS tasks while in flight in each aircraft and in the ground ambulance. Mean times for performance of each task in the aircraft and in the ground unit were analyzed using Dunnett's method for analysis of multiple means; alpha was set at 0.01., Results: Times required to perform all ALS tasks were significantly increased in the BO 105 setting compared to the setting of the BK 117 or the ground ambulance (p < 0.01). Times for performance of interventions in the BK 117 did not differ significantly from corresponding times in the ground setting., Conclusion: It appears that the environment of the BO 105 may impose limitations on the timely performance of certain ALS interventions.

Field trials were conducted during 1990 to evaluate the effects of preplant soil fumigation with 1,3-dichloropropene (1,3-D) on yield and fiber quality of furrow-irrigated cotton cultivars subjected to high population densities of Meloidogyne incognita. We measured the responses of eight upland cotton cultivars with different levels of root-knot nematode resistance and compared the responses of upland and Pima cottons. Reductions in lint weight ranged from 10 to 52% among cultivars grown in soil without 1,3-D fumigation compared with those grown in treated soil. Meloidogyne incognita reduced yields primarily by reducing the number of bolls on each plant, rather than by decreasing boll size. Cotton fiber quality varied among cultivars but was unaffected by M. incognita in either study. Upland cotton cultivar Acala 1517-88 and M-315/240 sustained less than half the yield reductions observed with M. incognita-susceptible cultivars Deltapine 41 and Paymaster 145. Sixty days after cotton emergence, fewer M. incognita second-stage juveniles were recovered from M-315/240 than all other cultivars.

Ultrasonic nebulizers may be particularly suitable for the administration of therapeutic aerosols to patients undergoing mechanical ventilation, but the amount of aerosol that reaches the patients' respiratory tract during ultrasonic nebulization has not been adequately studied. The delivery through an endotracheal tube of nebulized aerosols labeled with 99mTechnetium human serum albumin was therefore measured for five commercially available ultrasonic nebulizers using an in vitro model representing mechanical ventilation of an adult patient. Delivery of aerosol through the endotracheal tube ranged from 3.1 +/- 0.3% for Samsonic to 10.1 +/- 2.0% for Portasonic using 3 ml nebulizer solution. Increasing the volume of nebulizer solution to 18 ml (not possible for the Portasonic) increased delivery to 11.5 +/- 2.0 for the DP 100, 8.7 +/- 3.1 for Ultraneb, and 15.9 +/- 1.8% for Samsonic. Addition of a 600 ml aerosol storage chamber to the ventilator circuit increased delivery for the Samsonic (18 ml solution) to 22.3 +/- 5.0%. Aerosol delivery was also increased by reducing the respiratory rate and minute volume and by increasing the inspiratory time settings on the ventilator. These results confirm the potential value of ultrasonic nebulizers during mechanical ventilation and indicate that clinical trials in ventilated patients are warranted.

The use and variety of drugs administered to children as inhaled aerosols is increasing, but little is known about how much drug reaches the lung and how it is distributed there in different age groups. In this article the reasons for measuring aerosol deposition in children are discussed and the potential methods for doing this described. Of the methods available, only the use of radiolabelled aerosols gives accurate information on total lung deposition and distribution. The potential risk of the radiation exposure required for these measurements varies with the age of the child but seems to be small. Properly designed studies are expected to clarify the factors affecting lung deposition in children and identify methods of inhalation associated with efficient and predictable delivery of the drug. Measurements of radioaerosol deposition may therefore be justified in children when this information is expected to lead to improvements in the effectiveness or safety of their treatment.

The use of thrombolytic agents for both coronary and noncoronary indications is a rapidly progressing field. There has been substantial debate over which disease processes ultimately benefit from the use of thrombolytic agents. In addition, many recent studies have focused on comparing different thrombolytic agents and dosing regimens in an attempt to gain optimal therapeutic benefit with minimal risk. This paper discusses the current status of thrombolytic therapy for coronary artery disease, pulmonary embolus, peripheral vascular thrombosis, and cerebrovascular infarction.

The pulmonary deposition of nebulized pentamidine (300 mg, Respirgard II nebulizer) was measured in seven human immunodeficiency virus (HIV)-positive men using a new radiopharmaceutical, 123I-iodopentamidine. Mean total pulmonary deposition was 15.3 mg or 5.1% of the initial nebulizer dose. Further studies in two of the patients showed that at 24 h, 87% of deposited 123I was retained in the lungs. Small amounts of activity (expressed as a percentage of the initial nebulizer activity) were also detected over the thyroid (0.4%), bladder (1%) and gut (0.7%). The ratio of 123I activity to pentamidine concentration was similar in the nebulizer solution and urine. These results suggest that 123I-pentamidine may be sufficiently stable in vivo to be used to study the biodistribution of inhaled and parenteral pentamidine in humans.

The pharmacokinetics and metabolism of an intravenous dose (500 mg) of paracetamol were studied in a group of non-insulin dependent diabetic patients (n = 10) and in a group of healthy control subjects (n = 9). Paracetamol clearance, half-life and the partial clearance to paracetamol glucuronide were not significantly different, but the partial clearance to paracetamol sulphate was significantly reduced (62 +/- 18 vs 86 +/- 17 ml h-1 kg-1 (mean +/- s.d.)) and the renal clearance of paracetamol was significantly increased (56 +/- 20 vs 22 +/- 6 ml h-1 kg-1 (mean +/- s.d.)) in the non-insulin dependent diabetic patients, compared with the control group.

Several factors may affect the delivery of a nebulized aerosol to the lung through an endotracheal tube during mechanical ventilation. To study these factors in vitro, a model representing ventilation of an adult patient was constructed by linking a Servo 900C ventilator to a standard humidified circuit and an endotracheal (ET) tube positioned within a pipe representing the trachea. This was connected via a filter to a lung simulator. Nebulizers filled with 99mTc human serum albumin were positioned in the circuit, and the delivery of nebulized aerosol through the ET tube into the filter was measured using a gamma camera. With the use of an inspiratory phase-activated System 22 Acorn jet nebulizer, typical adult ventilator settings, and a 3-ml nebulizer solution volume, 5.4% of the nebulizer dose reached beyond the end of the ET tube. This was increased by increasing the inspiratory time, reducing the respiratory rate or respiratory minute volume, and by repositioning the nebulizer on the inspiratory limb of the Y-piece and was reduced by slowing the driving gas flow to the nebulizer. Under the same conditions, delivery was 3.1 and 4.4% using the Samsonic and Fisoneb ultrasonic nebulizers, respectively. Increasing the fill volume and the addition of an aerosol storage chamber increased delivery with all three nebulizers. These experiments suggest some simple ways of improving aerosol delivery during mechanical ventilation, including increasing the volume of nebulizer fill, repositioning the nebulizer in the ventilator circuit, adding an aerosol storage chamber, and adjusting ventilator settings to maximize delivery.

The haemodynamic effects of the venesection of one unit (450 ml) of blood over 9 min were measured using non-invasive techniques, in 14 healthy controls and 18 patients with coronary heart disease or hypertension. Venesection was associated with significant reductions in supine and standing systolic and diastolic blood pressure, stroke volume index and cardiac index, and increases in standing heart rate, in both patient groups. No significant differences were observed between the responses of subjects with and without cardiovascular disease. The authors conclude that, in contrast to established teaching, blood loss can be detected in its early stages by careful haemodynamic monitoring and that venesection can be performed safely without volume replacement in patients with stable cardiovascular disease.

We have evaluated Sramek's method of impedance cardiography as a non-invasive way of detecting the cardiovascular effects of drugs. We made cardiovascular measurements using the method during passive tilting and exercise 2 h after the oral administration of atenolol (50 and 100 mg), propranolol (40 and 80 mg), pindolol (5 and 10 mg), and placebo in seven separate studies involving eight healthy male volunteers. Equivalent doses of the pure antagonists atenolol (beta 1) and propranolol (beta 1, beta 2) produced similar reductions in heart rate, systolic blood pressure, and cardiac index, and increases in stroke volume and total peripheral resistance, particularly during exercise. In contrast the partial agonist pindolol produced increases in heart rate and cardiac index, and reductions in peripheral resistance at rest. During passive tilting and exercise pindolol reduced heart rate, but cardiac output and total peripheral resistance were unchanged except at the highest levels of exercise. The similar cardiovascular effects of atenolol and propranolol, but differing effects of pindolol, are consistent with reports using other methods of measurement. This suggests that impedance cardiography may have a place in the non-invasive assessment of the cardiovascular effects of drugs.

1. The cardiovascular effects of the proprietary cold remedies, Mu-cron and Boots Cold Relief tablets were compared with 'placebo' Boots Pain Relief tablets in a double-blind study involving 16 healthy volunteers. Measurements (impedance cardiography, forearm plethysmography) were made over 4 h after oral drug administration. 2. Two Mu-cron tablets (containing phenylpropanolamine [(1R,2S)- plus (1S,2R)-norephedrine] 50 mg) increased blood pressure (maximal effect 18 +/- 1/8 +/- 1 mm Hg (mean +/- s.e. mean), P less than 0.001), stroke volume (4.9 +/- 0.8 ml m-2, P less than 0.05), total peripheral resistance (243 +/- 27 dyn s cm-5 m2, P less than 0.001) and forearm vascular resistance (1.3 +/- 0.3 mm Hg ml-1 min, P less than 0.01) and reduced the ratio of pre-ejection period to ventricular ejection time (-0.031 +/- 0.003, P less than 0.05) and forearm blood flow (-2.6 +/- 0.5 ml min-1, P less than 0.05) but did not affect heart rate or cardiac index. 3. Two Boots Cold Relief tablets (containing phenylephrine 10 mg and caffeine 60 mg) caused a small and short-lived increase in total peripheral resistance but did not have consistent effects on other measurements. Two Boots Pain Relief tablets (containing caffeine 60 mg) did not have important cardiovascular effects. 4. The cardiovascular effects of phenylpropanolamine, including vasoconstriction and an increase in cardiac performance, are consistent with its alpha- and beta 1-adrenoceptor agonist action. While it may help the symptoms of rhinitis, its use in patients with heart disease or hypertension is hazardous.(ABSTRACT TRUNCATED AT 250 WORDS)

Previous studies from our laboratory suggest that humoral factors, namely glucagon, can account for approximately 30% of the splanchnic vasodilation in rats with prehepatic portal hypertension. A reduced vascular sensitivity to norepinephrine, vasopressin, and angiotensin II may contribute to the splanchnic vasodilation. However, neither glucagon nor an altered vasoconstrictor sensitivity can fully account for the splanchnic vasodilation observed in portal hypertensive subjects. Therefore, the present study was designed to examine the role of bile acids in the splanchnic hyperemia of portal hypertension since (1) serum bile acids are elevated in portal hypertensive subjects and (2) bile acids are potent intestinal vasodilators. Prehepatic portal hypertension was induced in Sprague-Dawley rats by surgical constriction of the portal vein. Ten to 14 days after the induction of portal hypertension, the enterohepatic circulation of control and portal hypertensive rats was surgically interrupted. The animals were placed in Bollman restraint cages and allowed to recover. Eighteen to 24 hr later, the rats were anesthetized with sodium pentobarbital and regional blood flow measured with radiolabeled microspheres. Normal and portal hypertensive animals without bile fistula served as controls. Plasma bile acid levels measured by radioimmunoassay were approximately 3.8 times higher in portal hypertensive animals than in control. Bile duct cannulation effectively depleted both normal and portal hypertensive animals of their circulating bile acid pool and significantly reduced portal venous inflow in portal hypertensive but not in control rats. A role for bile acids as partial mediators of the splanchnic hyperemia of portal hypertension is suggested since bile acid depletion did not completely abolish the gastrointestinal hyperemia.

Aerosolised pentamidine 300 mg in 5 or 6 ml solution was administered via 8 different nebuliser systems to 12 patients with acquired immunodeficiency syndrome. Using 99mTc human serum albumin as an indirect marker for pentamidine, pulmonary, extrapulmonary (gastric and oropharyngeal) and alveolar deposition of pentamidine were measured using a gamma camera. Side effects (visual analogue scales) and changes in lung function associated with each treatment were also quantified. Deposition was completed more rapidly with the ultrasonic than the jet nebulisers. Mean total pulmonary depositions (mg +/- SEM) were Respirgard II, 6.1 +/- 0.5; Centimist, 7.3 +/- 1.0, System 22 Mizer, 14.3 +/- 2.1; System 22 Mizer with particle separator; 4.5 +/- 0.4; System 22 Mizer with Optimist 2, 6.3 +/- 0.9; Fisoneb, 6.0 +/- 1.2; Pentasonic (Portasonic); 4.6 +/- 0.9; Samsonic, 2.9 +/- 0.4. Differences between the nebulisers for peripheral lung and alveolar deposition reflected this pattern. Side effects scores were largest with System 22 Mizer, Pentasonic (Portasonic), and Fisoneb, and these produced the greatest oropharyngeal and gastric deposition. The largest reductions in lung function were associated with System 22 Mizer. A 300 mg dose of pentamidine nebulised via Respirgard II is known to be effective prophylaxis for Pneumocystis carinii pneumonia when given once monthly. Our results show that equivalent pulmonary deposition can be produced by other nebulisers. System 22 Mizer gives over twice the deposition associated with Respirgard II, and used with a pentamidine dose of 150 mg is likely to produce an adequate lung dose for prophylaxis. This nebuliser, however, is associated with more marked side effects.

Using pneumotonometry combined with a Langham ocular blood-flow system, measurements of pulsatile ocular blood flow (POBF) were performed in eight ocular normotensive patients with implanted cardiac pacemakers, with the subjects assuming both the erect and the supine postures. Sequential measurements of POBF were made at pre-set values of heart rate over the physiological range between 60 and 120 beats/min at intervals of 10 beats/min. With patients in the supine position, measurements of cardiac output and stroke volume indices were also recorded by impedance cardiography. The mean pulse amplitude of the intraocular pressure (the ocular pulse) decreased as heart rate increased, and this change was statistically significant in both postures according to repeated-measures analysis of variance (erect: f = 18.7, P less than 0.0001; supine: f = 18.8, P less than 0.0001). As measured in supine patients following an increase in heart rate, the pulse amplitude decreased in parallel with a decline in stroke volume index (f = 18.8, P less than 0.0001). Up to a level of 90 beats/min, the mean POBF increased with heart rate, but it declined above this rate in both erect and supine postures. At all heart rates, intraocular pressure was higher when subjects were supine than when they stood erect (f = 4.3, P less than 0.001). At lower heart rates of 70 and 80 beats/min, ocular pulse volume and POBF were significantly lower in supine patients than in erect subjects (70 beats/min: t = 3.89, P less than 0.01 vs; t = 3.87, P less than 0.01; 80 beats/min: t = 2.85, P less than 0.05 vs; t = 2.87, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

A placebo controlled double blind crossover study was performed in 12 healthy volunteers to compare the cardiovascular effects of single oral doses of nifedipine (5, 10 and 15 mg) and nicardipine (20 and 30 mg) in the presence of atenolol 100 mg. Haemodynamic measurements were made by transthoracic electrical bioimpedance cardiography (TEBC) 2 h following drug administration during passive tilting, graded bicycle exercise (30-150 W) and recovery from exercise. In the absence of calcium channel blockade, atenolol reduced mean blood pressure, heart rate, and cardiac index, and increased stroke volume, peripheral resistance, pre-ejection period, and ventricular ejection time, particularly during and after exercise. In comparison with atenolol alone, addition of nifedipine or nicardipine reduced peripheral resistance but did not produce significant changes in stroke volume, cardiac output, dZ/dt [max], pre-ejection period (PEP). Ventricular ejection time (VET), PEP/VET, or Heather index at any point in the experiment. Similar reductions in peripheral resistance were produced by nifedipine 10 mg and nicardipine 20 and 30 mg. These apparently equivalent doses of nifedipine and nicardipine had similar effects on stroke volume, cardiac index, PEP/VET and Heather index. Thus the increases in ventricular performance previously demonstrated in association with nifedipine and nicardipine therapy were not observed in the presence of beta-adrenoceptor blockade. Under these conditions no important differences have been observed in the cardiovascular effects of these two calcium channel blockers.

A retrospective audit of a thyroid clinic revealed that only 67% of clinical assessments of thyroid status in patients receiving thyroxine replacement therapy were correct. The identification of patients on excessive doses of thyroxine appears to be the most difficult by clinical assessment alone, only 10% of those patients with a suppressed TSH level being identified. This study emphasises the importance of thyroid function tests in the assessment of patients on thyroxine replacement.

To assess the effect of posture on the distribution of nebulized pentamidine isethionate deposition in the lung, ten patients with AIDS were studied. Two nebulizer systems, System 22 Mizer (MedicAid) and Respirgard II (Marquest) were modified by adding 40 cm of corrugated tubing (volume 150 ml) to allow the patients to be studied in both the sitting and supine posture. Modification of the nebulizers caused a reduction in lung deposition in the sitting position for the System 22 Mizer but increased deposition in the Respirgard II compared with the unmodified apparatus. The ratio of upper to lower zone deposition (corrected for 133Xe distribution) was increased in the supine position for both devices (p less than 0.01). The best upper zone deposition was achieved with the unmodified System 22 Mizer in the sitting position. Respirgard II had the lowest nonpulmonary deposition and the lowest incidence of adverse effects. The supine position was associated with a redistribution of deposition to the upper zones. To attempt to reduce upper zone recurrence of Pneumocystis carinii pneumonia, the supine posture is suggested for less efficient nebulizer devices, ie, the Respirgard II, but for more efficient systems, ie, System 22 Mizer, the sitting position is probably suitable. This postulate needs to be confirmed by a clinical trial.

The cardiovascular effects of single oral doses of nifedipine (5 and 10 mg) and nicardipine (20 and 30 mg) were compared in a placebo controlled double-blind crossover study involving 8 healthy male volunteers. Two hours following drug administration stroke volume and cardiac index were measured non-invasively using transthoracic electrical bioimpedance cardiography during passive tilting, graded bicycle exercise, and recovery from exercise. Two separate experiments were performed in the absence of active drug to allow the reproducibility of the measurements to be assessed. Coefficients of variation (within experiment/between experiments) for cardiac index were 7.0%/19.9% at rest and 11.5%/9.3% at 180 W exercise. Both nifedipine and nicardipine increased stroke volume and cardiac index and reduced total peripheral resistance (mean blood pressure/cardiac index) at all times in the experiment. Reductions in peripheral resistance were similar for nifedipine 10 mg and nicardipine 20 mg but in these doses slightly larger increases in heart rate were produced by nifedipine, and in stroke volume and cardiac index with nicardipine. The study shows that the cardiovascular effects of nifedipine and nicardipine can be detected using impedance cardiography which is a simple, safe, and inexpensive technique. The differences between the effects of the two drugs were small. Although some were of statistical significance and are consistent with a less marked cardiodepressant effect for nicardipine, the clinical importance of these observations is uncertain. Further studies to examine the effect of oral nifedipine and nicardipine in patients with impaired ventricular function may be helpful in clarifying this tissue.

Numbers of plant-parasitic nematodes on corn growing under seven tillage regimes were monitored. Differences among treatments occurred for Helicotylenchus pseudorobustus, Pratylenchus spp., Xiphinema americanum, dorylaimids, and total numbers of nematodes. Except with members of the Tylenchinae, highest densities occurred in no-till ridge plots and lowest numbers occurred in spring- and fall-plowed pots.

Corn yields were measured after application of nematicides in 16 experiments, mostly in medium-to-heavily textured soil, at 12 locations in Iowa during 1973-1976. The average maximum yield increase in plots treated with nematicides was 21% over yields in untreated plots. Yields were correlated negatively with nematode numbers or nematode biomass in nearly all comparisons. Correlations of nematode numbers in the soil with yield averaged -0.56 for Helicotylenchus pseudorobustus, -0.45 for Hoplolaimus galeatus, -0.51 for Pratylenchus spp., and -0.64 for Xiphinema americanum. Correlation coefficients for numbers of nematodes in the roots and yield averaged -0.63 for Pratylenchus spp. and -0.56 H. galeatus. Correlation coefficients for yield and total number of nematodes averaged -0.65 in roots and -0.55 in soils. Negative correlations also were greater for comparisons of yield with total parasitic-nematode biomass than with numbers of individual nematodes of a species or total numbers of parasitic nematodes.

Eleven patients with treated hypothyroidism were investigated to examine the effects of time on their thyroid function tests. Each patient was clinically and biochemically euthyroid on once daily thyroxine replacement therapy, taken in the morning. TSH followed a diurnal rhythm with a peak level at 23.30 h and a trough level at 14.30 h. Four subjects had TSH trough levels within the normal range, but with peak levels outside this range. FT4 and FT3 levels fell from their highest levels some three hours after ingestion to the lowest levels just prior to the next dose. This study shows that there are significant time-related variabilities in TSH and thyroid hormone levels in treated hypothyroid patients. This should be taken into account when interpreting results of their thyroid function tests.

Little information is available regarding the levels of Meloidogyne incognita race 3 resistance in Acala 1517 cotton cultivars compared with cultivars grown outside the southwestern United States. Levels of M. incognita egg production were compared among commercial Acala cultivars 1517-E2, 1517-SR1, 1517-75, 1517-77BR, and SJ-5, resistant and susceptible standards Auburn 634 and M-8 and breeding lines Acala 5701-W and N6072 grown for 45 days in the greenhouse. The Acala 1517 cultivars all performed similarly, demonstrating moderate nematode resistance. Egg production on the 1517 cultivars was less than on SJ-5 and less than one-fifth that on M-8. Auburn 634 was most resistant, followed by N6072. Total egg production per plant and egg production per gram dry root were not correlated but proved to be reliable indicators of relative resistance to M. incognita.

1. Oral high-frequency oscillation (OHFO) may have important effects on aerosol deposition in the lungs. In order to investigate these, a technique was devised to measure regional deposition rates of a nebulized radiolabelled aerosol in the lungs during normal tidal breathing. 2. The effect of three frequencies of OHFO on pulmonary aerosol deposition rate (PADR) in four normal subjects and five patients with chronic airways obstruction (CAO) were assessed using the technique. 3. In separate experiments employing three normal subjects, the effect of OHFO was studied on the deposition rate of aerosol on the oropharynx and delivery apparatus, and on the amount and characteristics of aerosol inhaled by the subjects. 4. Total PADR was significantly reduced by OHFO at 8 Hz and 16 Hz in the normal subjects, and by all three frequencies of OHFO in the CAO patients. In the normal subjects, the regional distribution of aerosol deposition was unchanged, but in the CAO patients a larger proportion of total aerosol deposition occurred in peripheral lung. 5. OHFO reduced the oropharyngeal aerosol deposition rate, increased the loss of aerosol to the atmosphere before inhalation, and increased the deposition of aerosol on the delivery apparatus. The end result was a reduction in the amount of aerosol inhaled, and in the particle sizes measured at the mouthpiece. 6. We conclude that OHFO reduces the amount of aerosol inhaled, but may improve peripheral deposition of inhaled aerosol in patients with CAO. This effect may be of value in the clinical administration of nebulized drugs.

In-situ optical scanning of fluorescamine derivatives on thin layer silica gel plates provides a rapid method for the determination of multiple sulfonamides at levels below 0.1 ppm. Sample preparation is minimal. Homogenized liver or muscle is extracted with ethyl acetate and then back-extracted into 0.2M glycine buffer. After pH adjustment, the extract is washed with hexane and extracted with methylene chloride. The organic phase is evaporated to dryness and reconstituted in methanol. Pre-adsorbent layer silica gel plates are used for chromatography. The method has been applied to residues of sulfamethazine, sulfadimethoxine, sulfathiazole, sulfaquinoxaline, and sulfabromomethazine in cattle, swine, turkey, and duck tissues.