Gastroesophageal reflux: a common exacerbating factor in adult asthma

There is a unique yet common relationship between gastroesophageal reflux (GER) and asthma. This paper's discussion covers the lower esophageal sphincter (LES) and other components that form the anti-reflux barrier and how the barrier can be breached. There are three predominant theories on the asthma/GER connection; (1) the inhalation of microaspirate into the lungs causes an inflammatory response, (2) a vagally mediated reflex pathway occurring when acid is present in the esophagus, and (3) a combination of the first two theories. Available diagnostic tests for GER include the "gold standard," the 24-hour ambulatory pH monitor. Adult asthmatic patients with GER can present with atypical symptoms such as worsening nocturnal asthma or hoarseness and not have a single classic symptom like heartburn. Treatment is implemented in a step-wise approach first using education to introduce conservative anti-reflux measures, progressing to pharmacotherapy (acid suppressive agents and promotility agents) and finally surgical correction like the Nissen fundoplication to create a competent anti-reflux barrier, thus achieving improved asthma management.

A pilot study of intravenous ondansetron for hyperemesis gravidarum

OBJECTIVE

We attempted to determine whether the antiemetic ondansetron would be more effective than promethazine in treating hyperemesis gravidarum.

STUDY DESIGN

Patients with hyperemesis gravidarum who required hospital admission were randomized to receive either intravenous ondansetron (n = 15) or intravenous promethazine (n = 15) in a double-blind manner. Severity of disease was determined by electrolyte status, weight loss, ketonuria, and prior use of outpatient antiemetics. Outcome variables included degree of nausea, weight gain during treatment, days of hospitalization, and number of medication doses.

RESULTS

In this preliminary investigation ondansetron offered no advantage when compared with promethazine in the relief of nausea, weight gain, days of hospitalization (4.5 +/- 2.3 vs 4.5 +/- 1.5), and total doses of medication per hospitalization (2.1 +/- 1.2 vs 1.9 +/- 1.3).

CONCLUSION

This preliminary trial of ondansetron demonstrated no benefit over promethazine in patients hospitalized for hyperemesis gravidarum.

Diabetic ketoacidosis complicating pregnancy

OBJECTIVE

This report describes the physiologic alterations that predispose pregnant women to diabetic ketoacidosis and the experience in a tertiary center after adoption of aggressive management of diabetics.

STUDY DESIGN

In 1982 a protocol for strict surveillance of glucose homeostasis for pregnant diabetic patients and the early recognition and aggressive treatment of patients who do have diabetic ketoacidosis was initiated and has resulted in improved maternal and neonatal outcomes.

RESULTS

From 1986 through 1991 the incidence of diabetic ketoacidosis was 3% compared with an incidence of 22% from 1976 to 1981. During this same time the incidence of fetal death associated with diabetic ketoacidosis decreased from 35% to 10%.

CONCLUSION

Diabetic ketoacidosis and fetal morbidity/mortality can be reduced by aggressive management during pregnancy.

Incidence of adverse cardiopulmonary effects with low-dose continuous terbutaline infusion

OBJECTIVE

Our purpose was to determine the incidence of adverse cardiovascular effects of terbutaline sulfate when administered as a continuous subcutaneous infusion in women with arrested preterm labor.

STUDY DESIGN

Over a 6-year period records from 8709 women prescribed this therapy for preterm labor that had previously been arrested with other intravenous tocolytics were reviewed. These women were assessed daily for cardiovascular complaints and tolerance of the medication, while either in the hospital or at the home (by telephone). The main outcomes studied were the occurrence of pulmonary edema, sustained cardiac arrhythmias, chest pain, or myocardial ischemia. Any maternal death regardless of cause was also reviewed.

RESULTS

Of the 8709 subjects, 47 (0.54%) had one or more cardiopulmonary problems. Pulmonary edema developed in 28 patients (0.32%) while receiving continuous subcutaneous infusion of terbutaline, 5 at home and 23 in the hospital. Of the total, 17 women were being treated concurrently with large amounts of intravenous fluids and one to three other tocolytic agents. In the 11 remaining subjects, 4 were diagnosed with pregnancy-induced hypertension and/or multiple gestation. Nineteen patients experienced other adverse cardiovascular effects, including electrocardiogram changes, irregular heart rate, chest pain, or shortness of breath.

CONCLUSIONS

Continuous terbutaline infusion for women with stabilized preterm labor is associated with much fewer adverse effects than previous literature regarding intravenous beta-adrenergic agonist therapy would suggest.

Management of the obstetric patient with thrombocytopenia

Thrombocytopenia that complicates pregnancy can occur secondary to known maternal disease processes or may arise again during, and as a result of, gestation. A combination of maternal history, clinical presentation, and laboratory investigation usually leads the obstetrician to the proper diagnosis of the condition and, when necessary, dictates appropriate fetal intervention. Although the differential diagnosis of thrombocytopenia can be a frustrating and difficult exercise, especially in an emergent intrapartum environment, clinical persistence coupled with hematology consultation when appropriate usually will reward the provider and patient with the best chance to achieve optimal maternal-fetal outcome.

Emergent management of the patient in preterm labor

Clinicians who treat PTL should realize that side effects rarely occur when tocolytic medications are properly used. The beneficial effects of tocolytic therapy vastly outweigh the risks associated with their use for the prolongation of gestation. Even a short extension of in utero life for a few days or weeks can significantly and positively affect neonatal survival and long-term outcome. Although the opponents of tocolytic therapy argue that no reduction in the PTB rate has occurred since their introduction, this argument does not consider that the large majority of PTBs are not eligible for tocolytic intervention. If patients with clear indications for tocolysis could be compared with those that were not treated (which most studies have not done), a substantial beneficial effect of tocolytic administration probably would be demonstrated. Based on available data, we consider MgSO4 and terbutaline to be first-line tocolytics. Magnesium is used more often because of its lower side-effect profile. Indomethacin and nifedipine should be reserved for difficult or refractory preterm labor, and should only be used for intervals of < or = 48 hours. We have attempted to present a method of decision analysis which should be followed for every patient who is admitted to the obstetric care unit for a presumptive diagnosis of premature labor. We realize that many of the issues included here are controversial, however, we hope that by developing a decision tree (see Fig. 1), a more complete management scheme will be created and lead to improved care of the patient undergoing premature labor.

Parous patients' estimate of birth weight in postterm pregnancy

Our objective was to determine among postterm gestations (gestational age > or = 41 weeks) the accuracy of a parous patient's (n = 70) estimate of her newborn's birth weight and to compare the accuracy of clinical prediction with the assessment by the parturient (n = 40). During early labor 70 postterm parous subjects were asked to predict the birth weight of their neonate on the basis of their prior obstetric experiences. For comparison, a concurrent clinical estimate of the birth weight by the provider was also obtained in 40 of these patients. The incidence of macrosomia (birth weight > or = 4000 gm) among postterm parous mothers was 25.7%. The mean standardized error of the maternal estimate of birth weight was 85 +/- 76 gm/kg and 71.4% of their estimates were within +/- 10% of actual birth weight. Maternal estimate of birth weight > or = 4000 gm had a 94% specificity and 77% positive predictive value for a macrosomic fetus. Among 40 postterm parous women the clinical estimate had a mean standardized error (75 +/- 71 gm/kg) comparable to that of the maternal prediction (92 +/- 81 gm/kg) of birth weight (p = not significant). The mean standardized error among estimates for 11 macrosomic newborn infants who underwent both methods of estimation of birth weight was not significantly different. In conclusion, postterm parous women are at risk for delivery of a macrosomic fetus. Among these parturients, an estimate of birth weight by parous women is comparable to the clinical prediction of newborn weight by their providers.

Corticosteroid-induced arrest of HELLP syndrome progression in a marginally-viable pregnancy

Corticosteroid therapy in preterm pregnancy complicated by severe pre-eclampsia as HELLP syndrome temporarily stabilizes the HELLP syndrome. One such patient complicated by extreme prematurity was treated with long-term high-dose corticosteroid therapy. The HELLP syndrome was temporarily stabilized and additional in utero fetal maturation was gained.

The recurrence risk of the syndrome of hemolysis, elevated liver enzymes, and low platelets (HELLP) in subsequent gestations

OBJECTIVE

Although it is an important clinical issue, accurate prediction of recurrence risk for the syndrome of hemolysis, elevated liver enzymes, and low platelets (HELLP) has been problematic because of limited patient experience. This study was undertaken to determine the likelihood that this form of severe preeclampsia-eclampsia or any other hypertensive disorder would occur in a subsequent pregnancy.

STUDY DESIGN

An extensive retrospective analysis of medical records and patient follow-up regarding subsequent pregnancy outcome were undertaken for the 481 patients with HELLP syndrome managed at this tertiary medical center between Jan. 1, 1980, and Oct. 30, 1991. The Mississippi three-class system was used to define severity of disease on the basis of the lowest observed perinatal platelet count (class 1 < or = 50,000/microliters, class 2 > 50,000/microliters to < or = 100,000/microliters, and class 3 > 100,000/microliters to < or = 150,000/microliters).

RESULTS

Subsequent gestations (n = 195) occurred in 122 of 481 patients. Evaluable data were available for analysis in 161 of 195 possible pregnancies. Seventy-eight (48%) pregnancies were complicated by some type of hypertensive disorder, 44 (27%) of which had class 1, 2, or 3 HELLP syndrome. Non-HELLP preeclampsia-eclampsia was detected in 25 subsequent gestations (15%). Thus the total frequency of preeclampsia was 69 in 161 (43%). If the data for class 3 HELLP are completely excluded from the analysis, 81 subsequent evaluable and viable gestations were identified, 19 pregnancies with preeclampsia-eclampsia (23%) and 15 patients with HELLP syndrome (19%), for a total recurrence rate of 42%. Subsequent HELLP gestations were frequently delivered abdominally (64%) on average 2 weeks later than the index pregnancy (32.6 +/- 5.0 weeks versus 34.7 +/- 5.3 weeks). Delivery at < 32 weeks conferred a high risk (61%) for a similar preterm delivery in a subsequent gestation.

CONCLUSION

The risk of recurrence of the HELLP syndrome in our population is 19% to 27%. When data from all pregnancies with all forms of preeclampsia are considered, the risk of recurrence for any type of preeclampsia-eclampsia is 42% to 43%. A previous preterm delivery is a very high risk factor for recurrence of prematurity with preeclampsia-eclampsia.

Competency assessment and performance improvement for healthcare providers

This article discusses the implications of designing a comprehensive competency assessment program for healthcare providers. Increased liability for providers, institutions, and liability carriers is providing the impetus for change. Current methods to evaluate competency are limited; most methods include requirements that simply validate licensure and credentials. This article discusses the literature that supports methods for evaluating competency by assessing skills and proctoring. The author proposes a three-part model to ensure that competency assessment and performance improvement is the mainstay of an organization's quality management program. The model includes (a) a skills assessment inventory, (b) a standards review to promote compliance, and (c) a peer review program. Included are samples from two comprehensive skills inventories designed for orientations for physicians and nurses.

Assessment of the haemolytic activity of 2-butoxyethanol and its major metabolite, butoxyacetic acid, in various mammals including humans

2-Butoxyethanol (BE) is a glycol ether produced in volumes exceeding 335 million pounds/year for industrial and domestic uses. BE causes acute haemolytic anaemia in rats and some other mammals. While BE is inactive in vitro, 2-butoxyacetic acid (BAA) is a potent haemolytic agent in vivo and in vitro. This finding suggests that metabolic activation of BE to BAA is required for haemolysis of erythrocytes to occur in vivo. Haemolysis of red blood cells (RBC) by BAA is preceded by swelling (increased mean cell volume [MCV] and haematocrit [HCT]). In an attempt to assess the potential risk to humans exposed to BE, studies were designed to determine the in vitro effect of BAA on RBCs from 10 mammalian species including humans. Blood samples from each mammalian species (n = 3-5) were incubated with BAA at a final concentration of 0 (vehicle), 1 or 2 mM and kept at 37 degrees C in a gently shaking water bath. Complete blood counts (CBCs) were measured at 0, 1, 2 and 4 h, BAA caused a time- and concentration-dependent increase in MCV and HCT of blood from rats, mice and hamsters (rodents), rabbits (lagomorphs), and baboons (primates). In contrast, blood from pigs (artiodactyls), dogs and cats (carnivores), guinea pigs (rodents/marsupials), and humans (primates), was minimally affected by BAA. These results were confirmed in guinea pigs and rats in vivo. Gavage administration of BE (250 mg kg-1) to rats resulted in increased MCV and HCT followed by haemolysis (decreased RBCs). Identical treatment with BE resulted in no significant change in these parameters in guinea pigs.(ABSTRACT TRUNCATED AT 250 WORDS)

Control of proximal gastric bleeding: combined laparoscopic and endoscopic approach

Dieulafoy's lesion (exulceratio simplex) of the proximal gastric corpus is a more frequent cause of massive upper gastrointestinal hemorrhage than previously appreciated. Recent management has focused on interventional endoscopic and radiologic techniques, but these have been plagued by high rebleeding rates. The traditional surgical approach of suture control of the bleeding or wedge resection is effective but entails significant morbidity and mortality. This article describes endoscopically guided laparoscopic ligation of the feeding vessels in a patient with massive hemorrhage from a Dieulafoy's ulcer.

A prospective randomized study comparing surgical and percutaneous removal of intraaortic balloon pump

This prospective randomized study of 50 patients compares the prevalence of complications between surgical and percutaneous methods of removal of intraaortic balloons. All patients who had percutaneous placement of a 9.5F intraaortic balloon during a 6-month period were eligible for the study. Patients were excluded if the intraaortic balloon was placed surgically, if a coagulopathy was present, or if acute leg ischemia developed at any time after insertion. After informed consent, 25 patients were randomized to each method of removal. Two complications occurred in the surgical group, including a wound infection and a lymph fistula. In one patient in the percutaneous group, a false aneurysm of the femoral artery developed. There was no significant difference between the mean of 59 minutes for percutaneous removal and 47 minutes for operative removal of the balloon (p = 0.74). The percutaneous method is therefore more cost-effective, because it does not require the use of operating room personnel or equipment necessary for surgical removal. The results of this study indicate that the majority of percutaneously placed intraaortic balloons may be safely removed percutaneously. Surgical removal of 9.5F intraaortic balloons is recommended for patients with bleeding diatheses, hemorrhagic or ischemic complications, or for those in whom the intraaortic balloon was inserted with a surgical procedure.

Clinical management of the symptomatic but unruptured abdominal aortic aneurysm

Pain or tenderness of an abdominal aortic aneurysm is widely believed to signify acute expansion and imminent rupture. To assess the potential benefit of emergency operation for the group of patients with an acutely expanding aneurysm, the clinical course of 19 patients with a symptomatic but unruptured expanding abdominal aortic aneurysm was compared with 117 patients undergoing elective abdominal aortic aneurysm resection, and 69 patients having operation for a ruptured abdominal aortic aneurysm. Postoperative morbidity was high in the patients with an expanding abdominal aortic aneurysm, and included a 21% incidence of myocardial infarction, a 10% incidence of stroke, a 37% risk of ventilatory failure, and a 31% incidence of acute renal failure, which was not statistically different from the results in patients having ruptured abdominal aortic aneurysm resection. Patients undergoing elective abdominal aortic aneurysm resection had only an 8% risk of myocardial infarction, and only a 2% risk of stroke, ventilatory failure, or renal failure. The mortality rate for expanding abdominal aortic aneurysm resection was 26% compared to 35% for ruptured abdominal aortic aneurysm (p = 0.31). Both emergency operations had a mortality rate more than five times greater than the 5.1% after elective procedures (p = 0.008). Our findings emphasize the need for early and aggressive treatment of abdominal aortic aneurysm in the elective setting, even in the patient at high risk, and suggest that the preoperative assessment and modification of risk factors is important to prevent the cardiac, cerebrovascular, pulmonary, and renal complications seen accompanying an emergency operation of this magnitude.

The expression and purification of human rhinovirus protease 3C

Human rhinovirus type 14 protease 3C was expressed as a soluble and active protein in Escherichia coli. The protease was purified by a cationic-exchange step followed by gel filtration on a TSK 3000 column. The final yield of purified protease was in the range 0.5-1.0 mg/l culture grown to A550 = 1.0. Sequence analysis revealed that greater than 90% of the N-terminal residues were methionine. The enzyme activity of the purified protease was measured by cleavage of a synthetic peptide representing a predicted Gln/Gly viral polyprotein cleavage site. A mutant protease (Cys146----Ser) was produced and purified in the same way. The yield of mutant protease 3C was approximately 150 micrograms/l from a culture grown to A550 = 1.0. This mutant protease 3C did not cleave the synthetic peptide substrate.

The isolation and characterisation of human atrial natriuretic factor produced as a fusion protein in Escherichia coli

Human atrial natriuretic factor [ANF(1-28)] has been isolated from a fusion protein produced in Escherichia coli. ANF(1-28) was linked to a naturally occurring E. coli protein, chloramphenicol acetyltransferase, via unique cleavage sequences susceptible to either human thrombin digestion, or the chemical action of 2-(2-nitrophenylsulphenyl)-3-methyl-3'-bromoindolenine (BNPS-skatole). The linker sequences were Gly-Val-Arg-Gly-Pro-Arg and Trp respectively. The liberated ANF was purified by reversed-phase HPLC. Optimised cleavage conditions released 5-10% (by mass) of the maximal yield of ANF(1-28) from the fusion protein with the thrombin-susceptible linker, whilst a 2-5% (by mass) yield was observed from the fusion protein with the tryptophan linker after BNPS-skatole treatment. The purified cleavage products were biologically active and shown to comprise intact ANF(1-28). Fast-atom-bombardment mass spectrometry confirmed [MH]+ of 3079 m/z, consistent with ANF(1-28).

The establishment of polarity by hippocampal neurons in culture

By the end of the first week in culture, hippocampal neurons have established a single axon and several dendrites. These 2 classes of processes differ in their morphology, in their molecular composition, and in their synaptic polarity (Bartlett and Banker, 1984a, b; Caceres et al., 1984). We examined the events during the first week in culture that lead to the establishment of this characteristic form. Hippocampal cells were obtained from 18 d fetal rats, plated onto polylysine-treated coverslips, and maintained in a serum-free medium. The development of individual cells was followed by sequential photography at daily intervals until both axons and dendrites had been established; identification of the processes was confirmed by immunostaining for MAP2, a dendritic marker. Time-lapse video recording was used to follow the early stages of process formation. Hippocampal neurons acquired their characteristic form by a stereotyped sequence of developmental events. The cells first established several, apparently identical, short processes. After several hours, one of the short processes began to grow very rapidly; it became the axon. The remaining processes began to elongate a few days later and grew at a much slower rate. They became the cell's dendrites. Neurons that arose following mitosis in culture underwent this same sequence of developmental events. In a few instances, 2 processes from a cell exhibited the rapid growth typical of axons, but only one maintained this growth; the other retracted and became a dendrite. Axons branched primarily by the formation of collaterals, not by bifurcation of growth cones. As judged by light microscopy, processes are not specified as axons or dendrites when they arise. The first manifestation of neuronal polarity is the acquisition of axonal characteristics by one of the initial processes; subsequently the remaining processes become dendrites.

Cardiac tamponade in a newborn: a complication of hyperalimentation

Perforation of the heart by central venous catheters is an uncommon but life-threatening complication in the neonatal age group. Prevention requires an open insertion technique, the use of soft Silastic catheters, and the maintenance of the catheter tip above the right atrium. Rapid clinical deterioration with signs of tamponade suggests the diagnosis. Catheter withdrawal, early pericardiocentesis, and pericardiotomy with myocardial repair in selected cases contribute to survival.

Epidermoid cyst of the spleen successfully treated by marsupialization

Nonparasitic splenic cysts, although rare, should be considered in the differential diagnosis of persistent vague upper abdominal pain in children and young adults. These cysts, which are less common than traumatic pseudocysts, include hemangiomas, dermoids, lymphangiomas, and, as in the present case, epidermoid variants. Ultrasound is diagnostic. The pathogenesis of these lesions remains obscure. While some continue to advocate splenectomy as definitive treatment, an operation with splenic salvage should be possible, even in centrally located lesions.

Superior laryngeal nerve block: an aid to intubating the patient with fractured mandible

Awake nasotracheal intubation in the patient with a fractured mandible may be facilitated by combining bilateral superior laryngeal nerve block with topical application of local anesthetic to the nose, mouth, and trachea. Successful use of this technique is described in two such patients.

A murine monoclonal antibody that completely blocks the binding of fibrinogen to platelets produces a thrombasthenic-like state in normal platelets and binds to glycoproteins IIb and/or IIIa

To define better the role of the fibrinogen receptor in platelet physiology and to characterize it biochemically, a murine monoclonal antibody that completely blocks the binding of fibrinogen to the platelet surface was produced by the hybridoma technique with the aid of a functional screening assay. Purified F(ab')2 fragments and/or intact antibody completely blocked aggregation induced by ADP, thrombin, or epinephrine and the binding of radiolabeled fibrinogen to platelets induced by ADP. The antibody did not block agglutination of formaldehyde-fixed platelets by ristocetin or shape change induced by either ADP or thrombin. ADP- and epinephrine-induced release of ATP was completely inhibited by the antibody, but inhibition of release induced by collagen and thrombin was dose dependent and partial. The antibody also dramatically inhibited platelet retention in glass-bead columns, platelet adhesion to glass, and clot retraction. Thus, the antibody induced a thrombasthenic-like state. Immunofluorescent studies confirmed the specificity of the antibody for normal platelets and megakaryocytes and suggested that there is a marked decrease in detectable antigen in thrombasthenic platelets. Radiolabeled antibody bound to an average of approximately 40,000 sites on normal platelets but it bound to less than 2,000 sites on the platelets of a patient with thrombasthenia. The antibody immunoprecipitated both glycoproteins IIb and IIIa, and both glycoproteins bound to an affinity column of the antibody. These studies indicate that there is probably a single anatomic site that is crucial to the binding of all fibrinogen molecules and that this site is most likely on the glycoprotein IIb/IIIa complex. It also suggests that the thrombasthenic phenotype can be completely accounted for on the basis of the inhibition of fibrinogen binding to platelets.

Studies with a murine monoclonal antibody that abolishes ristocetin-induced binding of von Willebrand factor to platelets: additional evidence in support of GPIb as a platelet receptor for von Willebrand factor

A murine monoclonal antibody directed at or near a platelet membrane receptor for the von Willebrand factor was produced by the hybridoma technique. Purified F(ab')2 fragments and/or intact antibody completely blocked the agglutination of platelets induced by both ristocetin and bovine von Willebrand factor and the binding of von Willebrand factor antigen to platelets. The antibody also decreased platelet retention, prevented the reduction in platelet electrophoretic mobility caused by bovine von Willebrand factor, and decreased the serum prothrombin time. Radiolabeled F(ab')2 fragments bound to or approximately 2.5 X 10(4) sites on normal platelets with high affinity (KD or approximately 1.5 X 10(-8) M); there was no binding to platelets from 2 patients with the Bernard-Soulier syndrome. Immunoprecipitation and affinity chromatography studies indicated that the antibody binds to glycoprotein lb at a site contained on the externally oriented portion of the GPIb alpha chain (glycocalicin). An unidentified mol wt or approximately 20,000 molecule labeled by periodate/NaB3H4 coprecipitated and copurified with GPIb.

Anaesthesia of the upper airway using topical anaesthetic and superior laryngeal nerve block

Bilateral superior laryngeal nerve block was combined with topical application of local anaesthetic 140 times in 135 patients to anaesthetize the upper airway and facilitate tracheal intubation, laryngeal instrumentation, or to diminish the response to the endotracheal tube, in a patient already intubated. The technique was successful in 92% of attempts.

Anatomical dead space and airway resistance after glycopyrrolate or atropine premedication

The effects of atropine and glycopyrrolate on anatomical dead space, one and three second forced expiratory volume, maximal expiratory flow rate, and total forced expiratory volume were determined in ten healthy volunteers. Using Fowler's single breath nitrogen analyzing technique, atropine was found to increase dead space by 19.2 per cent at one hour, declining to 11.02 per cent at four hours. Glycopyrrolate increased dead space by 21.57 per cent at one hour, 29.28 per cent at two hours, and 26.65 per cent at four hours. When compared to the effects of saline control injection, the dead space increases are significant. The difference between glycopyrrolate and atropine is significant only at four hours. Increases in maximal expiratory flow rate induced by atropine and glycopyrrolate were significant at one-half hour, while atropine alone induced a significant increase in one second forced expiratory volume. Three second forced expiratory volume and total forced expiratory volume were not significantly altered.

Chromosome aberrations as a means to determine occupational exposure: an alternative

The biological basis, rationale, methodology, and results obtained from a laboratory test to identify chromosome aberrations has been described. The limited in vivo use of the method for measuring ionizing radiation exposure to patients, and the results obtained in these studies, have been presented and discussed. A protocol to use the method in an unique and specific application not yet fully explored, namely for the purpose of evaluating the biological effects of occupational radiation exposure of radiologic technologists, is proposed and advocated. The theory is advanced that this method of determining occupational radiation exposure may prove superior to personnel monitoring methods now employed.

The effect of enflurane and fentanyl anaesthesia on human platelet aggregation in vivo

In 30 patients undergoing major operations, and anaesthetized with either nitrous oxide, oxygen and enflurane, or nitrous oxide, oxygen and fentanyl, there was no significant alteration in platelet aggregation induced by either adenosine diphosphate or collagen. The absence of any significant effect on platelet function was confirmed by an unchanging thromboelastogram pattern during the study.

Aberrant conduction as a precursor to cardiac arrhythmias during anesthesia for oral surgery

In 109 patients, it was determined that halothane, when used to anesthetize patients for oral surgical procedures, causes an increased risk of serious cardiac arrhythmias when compared to methoxyflurane and fentanyl/droperidol. It is postulated that this is due to halothane's ability to decrease cardiac conduction and to facilitate the development of reentry phenomena. This decreased conduction may be accentuated by vagal efferent reflexes that have the same effect. The decrease in cardiac conduction was manifested by an ECG pattern of aberrant conduction. This phenomenon was not noted with either methoxyflurane or fentanyl/droperidol.

Post-operative renal failure caused by disseminated intravascular coagulation

A 22-year-old man suffered a stab wound of the femoral artery and vein. This was followed by disseminated intravascular coagulation. Renal failure then occurred presumably due to fibrin deposition in the small vessels of the kidney. The D.I.C. was successfully treated with heparin and the renal failure with peritoneal dialysis. It is suggested that D.I.C. and consequent alterations in regional blood flow following trauma are not uncommon, and search should be made for these phenomena in every case of major trauma.