Efficacy of temporomandibular joint arthroplasty and insertion of a Matthews device as treatment for ankylosis of the joint: a case series

Temporomandibular joint (TMJ) ankylosis is a condition in which bony or fibrous adhesion of the anatomical joint components results in loss of function. This is particularly distressing and debilitating for patients who struggle to maintain good oral hygiene, which results in additional pain, oral disease, and ultimately, a poor aesthetic profile. A retrospective chart review was carried out to document the cases of three patients who attended a single centre for the management of ankylosis of the TMJ. Consent for chart review and use of photographs was gained from each one. Charts were obtained, records reviewed, and each of the cases written up for presentation in a case series. All three underwent arthroplasty of the TMJ and insertion of Matthews devices (two patients unilateral, one bilateral). All were followed up postoperatively. They experienced significant improvements in vertical mouth opening which have been maintained to the present. The Matthews device allows movement and physiotherapy postoperatively whilst maintaining the surgically created space. This prevents impingement on the tissues placed between the glenoid fossa and mandible, and appears to prevent relapse and further ankylosis. To our knowledge, few studies to date have documented the use of the Matthews device following interpositional arthroplasty of the TMJ.

Very early lineage-specific chimerism after reduced intensity stem cell transplantation is highly predictive of clinical outcome for patients with myeloid disease

BACKGROUND

The importance of chimerism status in the very early period after hematopoietic stem cell transplantation is unclear. We determined PBMC and T-cell donor chimerism 50 days after transplantation and related this to disease relapse and overall survival.

METHODS

144 sequential patients underwent transplantation of which 90 had AML/MDS and 54 had lymphoma. 'Full donor chimerism' was defined as ≥99% donor cells and three patient groups were defined: 40% with full donor chimerism (FC) in both PBMC and T-cells; 25% with mixed chimerism (MC) within both compartments and 35% with 'split' chimerism (SC) characterised by full donor chimerism within PBMC and mixed chimerism within T-cells.

RESULTS

In patients with myeloid disease a pattern of mixed chimerism (MC) was associated with a one year relapse rate of 45% and a five year overall survival of 40% compared to values of 8% and 75%, and 17% and 60%, for those with SC or FC respectively. The pattern of chimerism had no impact on clinical outcome for lymphoma.

CONCLUSION

The pattern of lineage-specific chimerism at 50 days after transplantation is highly predictive of clinical outcome for patients with myeloid malignancy and may help to guide subsequent clinical management.

A Review Of Referral Patterns For Sagittal Synostosis In Ireland: 2008-2013

Sagittal synostosis (SS) is the commonest form of craniosynostosis. Children with sagittal synostosis in Ireland are treated in the National Paediatric Craniofacial Centre (NPCC) in Temple Street Children's University Hospital. This retrospective study analysed the correlation between referral patterns to the unit and age at operation. The notes of 81 patients referred over a 5-year period (April 2008 - April 2013) to the NPCC with non-syndromic SS were reviewed and demographics and referral information were recorded. Of 81 patients reviewed, 60 (74%) were referred before 6 months of age, while 21 (26%) had late referrals. Neonatologists referred 100% of infants before 6 months, paediatricians referred 71%, and GPs 64%. Later referral was associated with a more complex referral pathway, including multiple-steps of referral and unnecessary investigations. Improved clinician knowledge and emphasis on the importance of early referral may lead to a reduction in late referrals.

Cranial fasciitis located at the temporal region in a 2-year-old girl

INTRODUCTION

Cranial fasciitis is an exceedingly rare, benign, fibroblastic tumour of the skull of young children. It was first described in 1980 by Lauer and Enzinger as a subset of nodular fasciitis. There are fewer than 55 cases described in the literature.

CASE REPORT

We describe the presentation of a 2-year-old girl with a rapidly growing left temporal lesion, initially treated as an intramuscular haemangioma with propanolol. Following failure of response to this management, radiological and histological investigations indicated cranial fasciitis, and multidisciplinary surgery was undertaken via a bicoronal incision. Gross total resection was carried out, and the lesion was found to be adherent to but not infiltrating the dura. The petrous bone and zygomatic arch appeared destroyed, leaving a large temporal bony defect. This was repaired with a split calvarial graft from the outer table of the right parietal bone.

DISCUSSION

Histology confirmed a diagnosis of cranial fasciitis. She had an uneventful post-operative course and was discharged home well. A CT scan 8 months post-operatively showed no residual lesion and it was noted that the reconstruction had fully integrated and the zygomatic arch had reformed.

Current trends in simulation training in anesthesia: a review

Anesthesiology as a specialty has made numerous prescient commitments to better patient care. Physicians entering residency are reaching the zenith of their educational odyssey and primarily acquire knowledge and skill through active involvement. Simulation training and associated assessment offers a chance for active involvement to the learner. The goal of the training is to accelerate skill acquisition, improve skill retention and reduce the extinction of skills. Simulation training programs have been shown to increase the skill of anesthesiologists. This increase in skill is expected to translate to evidence of improved patient care. Direct evidence that simulation directly improves patient care continues to be difficult to establish. In the future, the intuitive benefit of simulation as a means to improve the safety and quality of patient care is likely to become established by clinical research.

Charpentier (1891) on the size-weight illusion

This paper offers background for an English translation of an article originally published in 1891 by Augustin Charpentier (1852-1916), as well as a summary of it. The article is frequently described as providing the first experimental evidence for the size-weight illusion. A comparison of experiments on the judged heaviness of lifted weights carried out by Weber (1834) and by Charpentier (1891) supports the view that Charpentier's work deserves priority; review of other experimental studies on the size-weight illusion in the 1890s suggests that the idea that the illusion depended on "disappointed expectations," especially with respect to speed of lift, became dominant almost immediately following the publication of Charpentier's paper. The fate of this and other ideas, including "motor energy," in 20th-century research on the illusion is briefly described.

The free gingival graft combined with the frenectomy: a clinical review

Abnormal labial frena are capable of retracting gingival margins, creating diastemas, and limiting lip movement. When these frena are present, the traditional frenectomy alone generally is successful. However, when the frenulum is extensive, the possibility of coronal reformation exists. Several procedures have combined the frenectomy with either a lateral pedicle flap, free papilla graft, or free gingival (mucosal) graft taken from the palate. Three case reports demonstrate the continued efficacy of the traditional palatal free gingival graft when the patient has an extensive frenulum or an area of minimal esthetic concern is involved.

Herbart's mathematical psychology

J.F. Herbart (1824/1890b) provided a mathematical theory about how mental ideas (Vorstellungen) in consciousness at Time 1 (T1) could compete, possibly driving 1 or more Vorstellungen below a threshold of consciousness. At T1 a Vorstellung A could also fuse with another, B. If at a later T2, A resurfaced into consciousness, it could help B to re-resurface into consciousness. This article describes the historical and mathematical background of Herbart's theory, outlines the mathematical theory itself with the aid of computer graphics, and argues that the theory can be applied to the modern problem of predicting recognition latencies in short-term memory (Sternberg's task; Sternberg, 1966)

A grouping interpretation of the modality effect in immediate probed recognition

In a series of experiments on immediate probed recognition for eight 3-digit numbers, it was shown that if the target modality involved auditory components and the effect of the similarity of the modality of the probe to that of the targets was controlled, unequivocal evidence was obtained for an auditory superiority effect (modality effect) for hit rates for the final items of the list. Moreover, false-alarm rates were significantly lower following targets with an auditory component than they were following silently seen targets. It is argued that this pattern of hits and false alarms is consistent with the idea that targets that have an auditory component yield memory representations that are better grouped as units than are those for targets that are only silently seen; in particular, if a new probe has a first digit that accidentally matches the first digit of a target item, it is more likely that the subject will mistakenly identify this new probe as old (give a false alarm) if the target has only been partially encoded because it was only silently seen.

A partial matching theory of the mirror effect in immediate probed recognition

A set of experiments on immediate probed recognition of digit triples is reported in which the variables were list length (five, six, seven, or eight triples), the probability that a probe was old (.33, .5, or .67), and whether the digit triples were presented with an auditory component or articulatory suppression. Previous work had suggested that the false alarm (FA) rate in this paradigm was lower when auditory information was available than when it was not; this observation had led to the development of the partial matching theory of immediate probed recognition, according to which FAs could arise not only as a result of unlucky guesses but also when new probes shared a first digit in common with a partially retained target triple. It was argued that partial memory representations were less likely following auditory presentation than following articulatory suppression. Partial matching theory is contrasted with the rational response theory, according to which all FAs are unlucky guesses; partial matching theory gave a better account of the present experimental data than did rational response theory. However, a logical relationship between the two theories was suggested, a consequence of which was that rational response theory could be modified to include partial matching in such a way as to account for mirror effects, not only in unusually difficult immediate probed recognition tasks, but also in the more commonly studied mixed test list paradigm involving words of high or low frequency.

The psychophysics of J-R-L Delboeuf (1831-1896)

Delboeuf's writings on psychophysics are little known nowadays. The object of this paper is to describe the psychological contributions of this eminent Belgian psychologist of the second half of the 19th century. A true pioneer of experimental psychology, his work on psychophysics began in 1865 at the University of Gand (Ghent) but was not published until 1873 and following years. His work in this area is characterised on the one hand by the adoption of a logarithmic law relating sensation strength to stimulus strength, but which differed from that of Fechner; and on the other hand by the utilisation of a psychophysical technique based on brightness contrast (now called the 'bisection method'). Even though, Delboeuf was classified by Fechner in his later writings as an opponent of his beliefs. Delboeuf was nevertheless one of his least-virulent critics and the only psychologist of that era to have adopted a logarithmic law. Delboeuf's work is not only of historic interest; his original ideas possess sufficient interest for present-day psychophysicists to reexamine them.

Transfusion management in pediatric and adolescent scoliosis surgery. Efficacy of autologous blood

STUDY DESIGN

A retrospective review of consecutive pediatric and adolescent patients who required posterior spinal fusion to correct scoliosis.

OBJECTIVES

To 1) measure the participation of pediatric patients in predeposit programs for autologous and directed blood donation 2) to assess the success of autologous predonation in preventing allogeneic blood use, 3) to determine whether transfusion indications differed between patients who received allogeneic blood and those who received autologous blood, and 4) to assess factors that predict transfusion requirements during scoliosis surgery.

SUMMARY OF BACKGROUND DATA

Authors of recent studies in adults have questioned whether transfusion of autologous blood is a cost-effective therapy when compared with the less-expensive alternative--transfusion of allogeneic blood. In children, the efficacy of autologous blood has not been assessed in a large population of surgical patients. In adults, the frequency of patient participation, the success of autologous donors in avoiding allogeneic transfusion, and the proportion of collected autologous units used during the perioperative period are measures used to establish the efficacy of autologous predonation programs.

METHODS

Hospital and clinic records for each patient who underwent posterior spinal fusion from September 1, 1989 through September 1, 1994 were reviewed. Blood bank consultation, autologous donation records, anesthesia records, surgical reports, and hospital records were reviewed. Seventy percent of patients (164 of 243) participated in autologous donation.

RESULTS

More than 90% of autologous donors successfully avoided receiving allogeneic blood. Patients with idiopathic scoliosis (n = 168) were more likely to participate in autologous donation (n = 144) and to avoid allogeneic blood (n = 135). Patients with neurologic causes of scoliosis more commonly used allogeneic or directed donation (56 of 75 patients). Nineteen patients with neuromuscular causes of scoliosis participated in autologous donation, but more than one half of this group (10 of 19 patients) required allogeneic blood in addition to autologous units.

CONCLUSIONS

Using measures of efficacy similar to those reported in studies of adults, autologous blood was found to be more effective in meeting the transfusion needs of pediatric patients who required posterior spinal fusion than in meeting those needs in adult surgical patients in previous studies.

Heparin detection by the activated coagulation time: a comparison of the sensitivity of coagulation tests and heparin assays

OBJECTIVE

Laboratory and point-of-care coagulation tests are frequently obtained to determine the presence of heparin after surgical procedures. The objective of this study was (1) to compare the sensitivity of the activated coagulation time (ACT), activated partial thromboplastin time (aPTT), protamine titration (Hepcon; HMS Medtronic, Hemotec, Englewood, CO), and thromboelastography (TEG) with heparin anticoagulation and (2) to determine how frequently residual heparin is present in the 24-hour period after heparin neutralization in cardiopulmonary bypass (CPB) patients.

DESIGN

A prospective study.

SETTING

A tertiary care university teaching center that performs more than 15,000 surgical procedures per year.

PARTICIPANTS

Vascular surgical (n = 17) and CPB (n = 29).

INTERVENTIONS

In vascular surgical patients, coagulation tests (ACT, protamine titration [Hepcon], and TEG) were obtained before and 90 minutes after heparin (50 to 60 U/kg IV) and compared with heparin concentration determined by factor Xa inhibition assay. In cardiac surgical patients, ACT and heparin concentrations were measured after anesthesia induction, during CPB, after protamine neutralization, and 3 as well as 6 hours after CPB. In addition to heparin concentrations and ACT measures, platelet counts, fibrinogen levels, and bleeding times were determined before and 3 and 24 hours after CPB.

MEASUREMENTS AND MAIN RESULTS

Ninety minutes after heparin, significant heparin concentrations were present in all vascular surgical patients, but ACT was elevated in only 4 of 17 patients. Protamine titration (Hepcon) correlated with the factor Xa inhibitory assay for heparin (r2 = 0.76). All 17 patients had an abnormal TEG (mean "R" time = 81 +/- 39 minutes) and a marked elevation of aPTT (135 +/- 35 sec [normal 22 to 33 seconds]) 90 minutes after heparin. In CPB patients, ACT did not correlate with heparin assays. After protamine neutralization of heparin in CPB patients, ACT returned to baseline despite the presence of heparin in 3 of 29 patients (0.22, 0.18, and 0.33 U/mL).

CONCLUSIONS

ACT was less sensitive to residual heparin anticoagulation than aPTT, TEG, and whole blood heparin assay. The whole blood heparin assay (Hepcon) provided sensitive and specific data about the presence of residual heparin. Despite the limitation of ACT in detecting heparin, the investigators found that residual heparin was not common in the period after uncomplicated CPB.

Postoperative care following single-stage laryngotracheoplasty

Single-stage laryngotracheoplasty (SSLTP) provides a method of correcting mild-to-moderate laryngotracheal stenosis while avoiding the risks of prolonged laryngeal stenting. Pediatric patients are orally intubated for 5 to 7 days postoperatively to ensure an adequate airway while edema resolves and healing begins. During this period, continuous neuromuscular blockade has been advocated in infants and young children to avoid endotracheal tube trauma to the fresh graft and potentially life-threatening accidental decannulation. Pulmonary atelectasis is the most common morbidity associated with prolonged neuromuscular blockade. Neuromuscular weakness also may follow prolonged paralysis and prolong hospitalization. This paper compares the postoperative course of 17 patients who underwent 18 SSLTP procedures by the senior author. The first 8 patients received continuous neuromuscular blockade in the early postoperative period. To reduce perceived morbidity, the last 9 patients were managed with a protocol that incorporated daily 4- to 8-hour "interruptions" of paralysis. Seven patients tolerated this protocol modification. As a group, these patients had less postoperative pulmonary atelectasis prior to extubation (p < .05) and were extubated sooner than patients receiving continuous neuromuscular blockade (p<.05) without compromising the surgical success of the procedure. Intermittent paralysis permitted for more accurate assessment of pain control and protected against accidental drug accumulation. Although self-extubation did not occur, diligent nursing care with adequate sedation and analgesia is necessary to avoid the risk of accidental extubation.

Analysis of changes in coagulation factors after postoperative blood loss in burn and non-burn patients

A prospective study of the postoperative kinetics of coagulation factors was undertaken in 23 burn patients and in six non-burn patients. All procedures resulted in a large volume blood loss. Fibrinogen, platelets and factors V, VIII and IX were measured serially. Burn patients returned all parameters to preoperative levels by 48 h postoperation, while non-burn patients showed a slower rate of return of platelets and factor V. This study suggests that burn patients may safely undergo re-operation at 48 h intervals for successive wound debridements if clinically necessary.

Anesthesia for magnetic resonance imaging in children: a low incidence of protracted post-procedure vomiting

STUDY OBJECTIVE

To determine the incidence and severity of vomiting in pediatric patients who have had inhalation anesthesia for magnetic resonance imaging (MRI).

DESIGN

A retrospective study of consecutive pediatric patients who had anesthesia for MRI.

SETTING

A large university hospital with an integrated clinic facility.

PATIENTS

234 children who required an MRI under general anesthesia over a 30 month period (July 1989 to February 1992).

MEASUREMENTS AND MAIN RESULTS

The duration of inhalation anesthesia was 105 +/- 33 minutes. Following anesthesia, the time to oral intake was 92 +/- 69 minutes. Eighteen patients (9%) experienced one or more episodes or emesis. In 14 of the 18 patients, vomiting occurred once and did not delay the intake of oral fluids or the discharge time from clinic when compared with the rest of the patients. Only one patient had frequent vomiting (more than three episodes), and all vomiting resolved spontaneously without anti-emetic therapy in less than eight hours following anesthesia.

CONCLUSIONS

Protracted post-procedure vomiting is an infrequent complication of inhalation anesthesia for MRI. Inhalation anesthesia may be a less important cause of postoperative vomiting than factors such as the type of operative procedure, use of opioids, or presence of postoperative pain.

Ligation of CD38 suppresses human B lymphopoiesis

CD38 is a transmembrane glycoprotein expressed in many cell types, including lymphoid progenitors and activated lymphocytes. High levels of CD38 expression on immature lymphoid cells suggest its role in the regulation of cell growth and differentiation, but there is no evidence demonstrating a functional activity of CD38 on these cells. We used stroma-supported cultures of B cell progenitors and anti-CD38 monoclonal antibodies (T16 and IB4) to study CD38 function. In cultures of normal bone marrow CD19+ cells (n = 5), addition of anti-CD38 markedly reduced the number of cells recovered after 7 d. Cell loss was greatest among CD19+ sIg- B cell progenitors (mean cell recovery +/- SD = 7.2 +/- 11.7% of recovery in control cultures) and extended to CD19+CD34+ B cells (the most immature subset; 7.6 +/- 2.2%). In contrast, CD38 ligation did not substantially affect cell numbers in cultures of normal peripheral blood or tonsillar B cells. In stroma-supported cultures of 22 B-lineage acute lymphoblastic leukemia cases, anti-CD38 suppressed recovery of CD19+ sIg- leukemic cells. CD38 ligation also suppressed the growth of immature lymphoid cell lines cultured on stroma and, in some cases, in the presence of stroma-derived cytokines (interleukin [IL] 7, IL-3, and/or stem cell factor), but did not inhibit growth in stroma- or cytokine-free cultures. DNA content and DNA fragmentation studies showed that CD38 ligation of stroma-supported cells resulted in both inhibition of DNA synthesis and induction of apoptosis. It is known that CD38 catalyzes nicotinamide adenine dinucleotide (NAD+) hydrolysis into cyclic ADP-ribose (cADPR) and ADPR. However, no changes in NAD+ hydrolysis or cADPR and ADPR production after CD38 ligation were found by high-performance liquid chromatography; addition of NAD+, ADPR, or cADPR to cultures of lymphoid progenitors did not offset the inhibitory effects of anti-CD38. Thus, anti-CD38 does not suppress B lymphopoiesis by altering the enzymatic function of the molecule. In conclusion, these data show that CD38 ligation inhibits the growth of immature B lymphoid cells in the bone marrow microenvironment, and suggest that CD38 interaction with a putative ligand represents a novel regulatory mechanism of B lymphopoiesis.

Packed red cells in acute blood loss: dilutional coagulopathy as a cause of surgical bleeding

The purpose of this study was: 1) to define coagulation abnormalities in patients who receive red cell concentrates rather than whole blood for large volume blood loss (greater than 0.5 blood volume); and 2) to determine when coagulation abnormalities lead to increased bleeding in the massively transfused surgical patient. We studied 32 ASA physical status I or II patients (mean age 15.6 +/- 2.3 yr) who lost more than 50% of their blood volume during elective posterior spinal stabilization. Crystalloid solutions and packed red cell concentrates were used to replace blood and fluid losses. Invasive hemodynamic measures, urinary output, and serial hematocrit determinations were used to help maintain a constant intravascular volume and confirm the estimates of blood loss. The quality of hemostasis was assessed during operation. In 15 of the 32 patients, surgical hemostasis remained effective throughout posterior spinal fusion. A coagulation profile (prothrombin time [PT] and activated partial thromboplastin time [aPTT], platelet count, and fibrinogen) was measured at the conclusion of operation in these patients. In 17 patients, increased surgical bleeding as a result of decreased clot formation and increased bleeding from the wound was present. In these 17 patients at the time increased bleeding was diagnosed, hemostatic tests (PT, aPTT, fibrinogen, platelet count, and coagulation factor assays V, VIII, and IX) were obtained.(ABSTRACT TRUNCATED AT 250 WORDS)

Pancreatic duct obstruction treated with percutaneous antegrade insertion of a metal stent: report of two cases

Expanding metal stents were used to treat symptomatic pancreatic duct obstruction in two patients with chronic pancreatitis. Both patients initially underwent percutaneous external pancreatic duct drainage and then had metal stents inserted for internal drainage. Both patients remained asymptomatic, and the stents were patent during short-term follow-up periods of 6 and 9 months, respectively. Percutaneous insertion of metal stents, which can be performed to treat pancreatic duct obstruction after a trial of external drainage has been shown to relieve the patient's symptoms, should be considered as an alternative to endoscopic stent placement or surgical drainage.

Comparative hemodynamic depression of halothane versus isoflurane in neonates and infants: an echocardiographic study

The purpose of this study was to measure and compare the relationship of cardiovascular depression and dose during equal potent levels of halothane and isoflurane anesthesia in neonates (n = 19) (16.7 +/- 6.9 days) and infants (n = 54) (6.1 +/- 3.1 mo). Seventy-three children had heart rate, arterial blood pressure, and pulsed Doppler pulmonary blood flow velocity as well as two-dimensional echocardiographic assessments of left ventricular area and length recorded just before anesthesia induction. Anesthesia was induced by inhalation of increasing inspired concentrations of halothane or isoflurane in oxygen using a pediatric circle system and mask. During controlled ventilation, halothane and isoflurane concentrations were adjusted to maintain 1.0 MAC and then 1.5 MAC (corrected for age), and echocardiographic and hemodynamic measurements were repeated. A final cardiovascular measurement was recorded after intravenous administration of 0.02 mg/kg of atropine. All measurements were completed before tracheal intubation and the start of elective surgery. In neonates, 1.0 MAC concentrations of halothane and isoflurane decreased cardiac output (74% +/- 16%), stroke volume (75% +/- 15%), and ejection fraction (76% +/- 15%) similarly from awake levels. Decreases in cardiac output, stroke volume, and ejection fraction with halothane and isoflurane were significantly larger at 1.5 MAC (approximately 35% decreases from awake values) than at 1.0 MAC. Heart rate decreased significantly during 1.5 MAC halothane anesthesia (94% +/- 4%) but remained unchanged during isoflurane anesthesia. In infants, 1.0 MAC halothane and isoflurane decreased cardiac output (83% +/- 12%), stroke volume (78% +/- 12%), and ejection fraction (74% +/- 12%) when compared with awake measures.(ABSTRACT TRUNCATED AT 250 WORDS)

Application of digital signal processing to hearing aids: a critical survey

An audiologic rationale for the application of digital signal processing techniques to hearing aids is developed. These techniques enable complex processing beyond that possible in presently available analog aids. A critical survey of algorithms for filtering, nonlinear processing, noise reduction, speech enhancement, and feedback reduction is presented. The paper concludes with a discussion of practical considerations for implementation.

The additive contribution of nitrous oxide to isoflurane MAC in infants and children

The purpose of this study was to determine the contribution of nitrous oxide to isoflurane MAC in pediatric patients. MAC was determined in 47 infants and small children (mean ages 16.6 +/- 6.7 months) during isoflurane and oxygen anesthesia (n = 11) and isoflurane and nitrous oxide anesthesia (25% nitrous oxide [n = 12], 50% nitrous oxide [n = 12], and 75% nitrous oxide [n = 12]). After assigning patients to one of four groups, anesthesia was induced with increasing inspired concentrations of isoflurane in oxygen. After anesthetic induction and tracheal intubation, ventilation was controlled (carbon dioxide partial pressure = 32 +/- 5 mmHg), and nitrous oxide was added to the inspired gas mixture to achieve end-expired nitrous oxide concentrations of 0, 25, 50, or 75%. Inspired and expired gas samples were obtained from a distal sampling port in the tracheal tube. The response to skin incision in each patient was assessed at a previously selected end-tidal concentration of isoflurane. The MAC of isoflurane was determined in each group using the up-and-down method described for evaluating quantal responses. The mean duration of constant end-tidal concentrations prior to skin incision was 14 +/- 7 min (range 6-46 min). The ratio of expired to inspired nitrous oxide and isoflurane concentrations during the period of constant end-tidal concentrations was 0.96 +/- 0.01 and 0.93 +/- 0.03 respectively. The MAC of isoflurane in oxygen was 1.69 +/- 0.13 vol% (mean +/- standard deviation).(ABSTRACT TRUNCATED AT 250 WORDS)

Transrectal Ultrasound of Prostatic Carcinoma: A new way to evaluate benign and malignant conditions

The purpose of this paper is to review the indications for transrectal ultrasound; to briefly describe the sonographic technique; to describe the sonographic findings of prostatic carcinoma; to review the indications for transrectal sonographic-guided biopsy; and to discuss the controversles of routine screening and staging.

Hemodynamic responses to nitrous oxide during inhalation anesthesia in pediatric patients

STUDY OBJECTIVE

To measure the hemodynamic changes produced by nitrous oxide (N2O) during halothane and isoflurane anesthesia in infants and children.

DESIGN

A repeated measures design in two groups of infants and small children.

SETTING

Operating rooms at a university hospital.

PATIENTS

Nineteen healthy unmedicated infants and small children (mean age 12 months) who required elective surgery.

INTERVENTIONS

Prior to anesthesia induction, cardiovascular measurements were recorded using pulsed Doppler and two-dimensional echocardiography. Following anesthesia induction with halothane (n = 10) or isoflurane (n = 9) in oxygen (O2) and air, anesthetic measures were stabilized at 1.0 minimum alveolar concentration (MAC) and cardiovascular measures were repeated. After 30% N2O was added to the 1.0 MAC anesthetic concentration, a third set of cardiovascular measurements was recorded. A final cardiovascular data set was measured 5 minutes following an increase in N2O concentration to 60%.

MEASUREMENTS AND MAIN RESULTS

Mean arterial pressure (MAP), cardiac index (CI), stroke volume (SV), and ejection fraction (EF) decreased similarly and significantly at 1.0 MAC halothane and isoflurane. Heart rate (HR) increased during isoflurane anesthesia but decreased during halothane anesthesia. The addition of N2O resulted in a decrease in HR, CI, and MAP when compared to 1.0 MAC levels of halothane or isoflurane; however, SV and EF were not significantly changed from levels measured during 1.0 MAC halothane or isoflurane.

CONCLUSIONS

The addition of N2O to halothane and isoflurane anesthesia in infants and children decreased HR. This decrease led to a decrease in cardiac output (CO). Unlike with adults, N2O did not produce cardiovascular signs of sympathetic stimulation in infants and children.

Additive contribution of nitrous oxide to halothane MAC in infants and children

Fifty-one infants and small children (14.7 +/- 7.2 mo) were studied to determine the MAC of halothane in O2 (n = 11) and in the presence of three different nitrous oxide (N2O) concentrations (25% [n = 13], 50% [n = 13], and 75% [n = 14]). In the three N2O groups, after randomly assigning patients to an N2O group, anesthesia was induced with halothane and N2O using a pediatric circle system. After endotracheal intubation, halothane and N2O end-expired concentrations were adjusted to predetermined concentrations. The initial halothane concentrations in each group were based on the assumption that each percent N2O reduced halothane concentrations by 0.01 vol % (assumed halothane MAC = 1.0 vol %). Based on the response of the preceding subject in each group, halothane concentrations were increased or decreased depending on whether the response was to move or not to move, respectively, in response to the surgical incision. The mean duration of constant end-tidal concentrations before skin incision was 10 min. End-tidal gases were sampled and measured from a separate distal sampling port of an endotracheal tube during controlled ventilation (Perkin-Elmer Mass Spectrometer). The MAC value for halothane in O2 was 0.94 +/- 0.08 vol % (mean +/- SD). The MAC values of halothane in the presence of 25%, 50%, and 75% N2O were 0.78 +/- 0.12 vol %, 0.44 +/- 0.10 vol %, and 0.29 +/- 0.06 vol %, respectively. All concentrations of N2O significantly reduced the MAC of halothane. A regression analysis through all four data points yielded a linear relationship (r2 = 0.87) with a predicted MAC for N2O of 105 vol %. Unlike halothane and isoflurane, the predicted MAC of N2O in infants and children is similar to that reported by others in adults. Similar to the results of clinical studies in adults, the contribution of N2O to halothane MAC in children is additive.

Neuromuscular and cardiovascular effects of mivacurium chloride in surgical patients receiving nitrous oxide-narcotic or nitrous oxide-isoflurane anaesthesia

The neuromuscular and cardiovascular effects of mivacurium chloride were studied during nitrous oxide-oxygen narcotic (fentanyl) (n = 90) and nitrous oxide-oxygen isoflurane (ISO) anaesthesia (n = 45). In addition, a separate group (n = 9) received succinylcholine during fentanyl anaesthesia to compare its neuromuscular effects with mivacurium. Mivacurium was initially administered as a single bolus in doses from 0.03 mg.kg-1 to 0.25 mg.kg-1 to study the dose-response relationships, as well as the cardiovascular effects of mivacurium. Neuromuscular block (NMB) was measured by recording the twitch response of the adductor pollicis muscle following ulnar nerve stimulation (0.15 Hz, 0.2 ms supramaximal voltage). The ED95 values for mivacurium were estimated to be 0.073 mg.kg-1 and 0.053 mg.kg-1 in the fentanyl and ISO groups respectively. The duration of block (time from injection to 95 per cent recovery) for a dose of 0.05 mg.kg-1 mivacurium was 15.3 +/- 1.0 min and 21.5 +/- 1.3 min for fentanyl and ISO anaesthesia, respectively. The recovery index (25-75 per cent) between initial bolus dose (6.1 +/- 0.5 min), repeat bolus doses (7.6 +/- 0.6 min), mivacurium infusion (6.7 +/- 0.7 min) and succinylcholine infusion (6.8 +/- 1.8 min) were not significantly different. There was minimal change in mean arterial pressure (MAP) or heart rate (HR) following bolus doses of mivacurium up to 0.15 mg.kg-1. Bolus administration of 0.20 mg.kg-1 or 0.25 mg.kg-1 of mivacurium decreased MAP from 78.2 +/- 2.5 to 64.0 +/- 3.2 mmHg (range 12-59 per cent of control) (P less than 0.05). The same doses when administered slowly over 30 sec produced minimal change in MAP or HR.

Changes in coagulation factors in patients with burns during acute blood loss

A prospective study was undertaken to determine the change in coagulation factors in patients undergoing tangential excisions of burn wounds when red blood cells preserved with ADSOL (adenine, dextrose, saline, and mannitol) and crystalloid solution were used for volume replacement. Nine patients with burns were studied, three on two separate occasions. No patient had a history of a bleeding disorder or had taken aspirin within 10 days of surgery. Results of preoperative coagulation studies were all within normal limits. The initial levels of coagulation factor and rates of removal were compared with those of 12 patients without burns who were undergoing elective surgery and who also had massive intraoperative blood loss. Coagulation factor levels measured included the platelet count, fibrinogen, factors V, VIII, and IX. These were determined before blood loss and each time loss and replacement of one third of a patient's calculated blood volume occurred during a tangential excision of a burn wound. The data showed that patients with burns have significantly higher baseline levels of platelets, fibrinogen, and factor VIII than patients without burns do. The removal rates of platelet and factor IX are significantly lower among patients with burns than among patients without burns. No patient in the study group developed a coagulopathy or received fresh frozen plasma or platelet supplementation. These findings suggest that the intraoperative blood losses that occurred during tangential excisions of burn wounds were made safe by the higher than normal preoperative levels of platelets, fibrinogen, and factor VIII and by the slow wash-out curve for platelets and factor IX. Prophylactic use of either fresh frozen plasma or platelet concentrates is not indicated unless a specific deficit or coagulopathy has been identified.

Haemodynamic effects of rectal methohexitone for induction of anaesthesia in children

Pulsed Doppler and two-dimensional echocardiography were used to determine the haemodynamic effects of rectal methohexitone in 12 children 32.4 +/- 3.8 months old and weighing 13.3 +/- 1.1 kg (mean +/- SEM). Heart rate, blood pressure and echocardiographic measurements of cardiac output, stroke volume and left ventricular end-diastolic and end-systolic volumes were obtained prior to the induction of anaesthesia. Anaesthesia was induced with 25 mg.kg-1 two per cent rectal methohexitone. Immediately following the onset of sleep all cardiovascular measurements were repeated. Following the induction of anaesthesia with rectal methohexitone there was a significant increase in heart rate. Blood pressure, cardiac index, stroke volume and ejection fraction were unchanged. It is concluded that rectal administration of two per cent methohexitone for the induction of anaesthesia in healthy paediatric patients has minimal haemodynamic effect.

Haemodynamic effects of atropine during halothane or isoflurane anaesthesia in infants and small children

In this study, two-dimensional and pulsed Doppler echocardiography were used to measure cardiovascular changes before and after IV atropine in 31 infants and small children during halothane (n = 15) or isoflurane (n = 16) anaesthesia. Prior to induction of anaesthesia heart rate (HR), mean blood pressure (MBP), and two-dimensional echocardiographic dimensions of the left ventricle and pulmonary artery blood flow velocity were measured by pulsed Doppler echocardiography. Cardiovascular measurements were repeated while anaesthesia was maintained at 1.5 MAC halothane (n = 15) or isoflurane (n = 16). Atropine 0.02 mg.kg-1 IV was then administered and two minutes later, a third set of cardiovascular data was obtained. Heart rate decreased during halothane anaesthesia but did not change significantly during isoflurane anaesthesia. Mean blood pressure, cardiac output (CO) and stroke volume (SV) decreased similarly during 1.5 MAC halothane or isoflurane anaesthesia. Ejection fraction (EF) decreased and left ventricular end-diastolic volume (LVEDV) increased significantly in both groups, but decreases in EF (32 +/- 5 per cent vs 18 +/- 5 per cent) and increases in LVEDV (18 +/- 7 per cent vs 7 +/- 5 per cent) were significantly greater during halothane than during isoflurane anaesthesia. Following atropine, HR increased more in the patients maintained with halothane (31 +/- 6 per cent), than during isoflurane anaesthesia (18 +/- 5 per cent). Atropine increased CO in both groups of patients, but SV and EF remained unchanged. When compared with awake values, HR increased similarly and significantly (18 +/- 4 per cent) following atropine in both groups, and CO returned to control levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of an animal model for teaching fibreoptic tracheal intubation

Twenty-seven anaesthesia faculty, fellows and residents compared a standard intubating mannequin and an anaesthetized pig as models for teaching fibreoptic tracheal intubation. When likened to the clinical situation, the anatomic characteristics of the pig airway were rated as significantly more realistic than the airway characteristics of the mannequin with the exception of the appearance of the epiglottis. In addition, the overall score for the pig model was significantly higher than the score for the mannequin and 26 of 27 evaluators rated the anaesthetized pig as the more effective teaching model. We conclude that an anaesthetized, spontaneously breathing pig is a valid model for teaching fibreoptic endotracheal intubation.

Pharmacokinetics of two per cent rectal methohexitone in children

Plasma methohexitone concentrations were determined in 60 children, aged one to six years, following administration of 15 mg.kg-1, 20 mg.kg-1, 25 mg.kg-1 or 30 mg.kg-1 two per cent rectal methohexitone. Time to the onset of sleep was determined by a blinded observer and venous blood samples obtained 15, 30, 45 and 120 minutes following drug administration. Fifty of 60 children were asleep within 15 minutes. Nine of the ten children that did not fall asleep were sedate and could be separated easily from their parents to undergo inhalational induction of anesthesia. Time to the onset of sleep was inversely related to the dose of rectal methohexitone administered. Sleep was achieved more reliably following the use of 25 to 30 mg.kg-1 rectal methohexitone. In addition, plasma methohexitone concentrations following 30 mg.kg-1 rectal methohexitone were significantly higher for up to 120 minutes following drug administration than the plasma concentrations achieved after 15 mg.kg-1 or 20 mg.kg-1 methohexitone. There was no difference in the incidence of complications. The authors recommend that clinical circumstances be carefully considered and the dose of rectal methohexitone administered be individualized to meet the specific anaesthetic requirements of each child.

Coagulation changes during packed red cell replacement of major blood loss

A greater proportion of blood replacement needs are being met by packed red cell concentrates rather than whole blood in situations of major blood loss. Twelve patients, who required major blood replacement during elective surgery, were studied to determine the changes in coagulation when packed red cells were used to replace major blood loss. In addition, the coagulation abnormalities present at the time an observer noted excessive bleeding were determined. Prior to blood product replacement and after the estimated loss of each 0.3 blood volume, coagulation tests were obtained including prothrombin time (PT), partial thromboplastin time (aPTT), platelet count, thrombin time (TT), fibrinogen levels, and assays of coagulation Factors V, VIII, and IX. Coagulation tests were repeated when clinical hemostasis was judged inadequate by the anesthesiologist and attending surgeon. Significant decreases in platelet count, fibrinogen levels, and Factor V, VIII, and IX levels occurred as increasing blood volumes were replaced. Increases in PT and aPTT above control occurred in nine of the 12 patients prior to replacement of 1 blood volume; none of the nine patients had increased clinical bleeding. In four of seven patients who had blood replacement of greater than 1 blood volume, increased clinical bleeding was noted by the observer. Platelet counts were less than 100,000/mm3 in each of these four patients, and a platelet concentrate obtained by pheresis of a single donor was administered. In two of the four patients platelet counts increased, but clinical bleeding did not resolve.(ABSTRACT TRUNCATED AT 250 WORDS)

The neuromuscular blocking and cardiovascular effects of doxacurium chloride in patients receiving nitrous oxide narcotic anesthesia

The purpose of this study was to evaluate neuromuscular and cardiovascular effects of doxacurium chloride, a new long-acting neuromuscular blocking agent, during a stable state of nitrous oxide and narcotic anesthesia. Ninety-three ASA physical status I or II patients were studied after informed written consent had been obtained. Eighty-one patients (group A) received doxacurium. The 81 patients were divided into nine subgroups according to the dose of doxacurium administered (0.01-0.06 mg.kg-1). Patients in a control group (group B) (n = 12) received pancuronium. To assess neuromuscular responses, a force displacement transducer recorded the twitch response of the adductor pollicis muscle following ulnar nerve stimulation. The ED50 and ED95 for doxacurium were estimated to be 0.013 mg.kg-1 and 0.023 mg.kg-1, respectively. The time to maximum twitch suppression following a dose of 1.0 (ED95) and 1.7 (ED95) was 10.3 +/- 1.3 min and 7.6 +/- 0.8 min, respectively. After an ED95 dose of doxacurium the time to spontaneous recovery to 95% of control twitch height was 73.7 +/- 8.7 min. With larger doses of doxacurium, 0.04 mg.kg-1 (1.7 X ED95) and 0.05 mg.kg-1 (2.2 X ED95), the time to spontaneous recovery to 95% of control twitch height was 125.8 +/- 24.8 and 204.0 +/- 21.2 minutes, respectively. When 25% twitch height recovery or more was present the reversal of doxacurium induced neuromuscular blockade was prompt.(ABSTRACT TRUNCATED AT 250 WORDS)

Uptake and subcellular localisation of bismuth in the gastrointestinal mucosa of rats after short term administration of colloidal bismuth subcitrate

Despite the topical action of colloidal bismuth subcitrate in promoting the healing of peptic ulcers, slight absorption of bismuth from the gastrointestinal tract has been reported in colloidal bismuth subcitrate-treated animals and man. The uptake and subcellular distribution of bismuth by the gastrointestinal tract of rats after 24 hours of colloidal bismuth subcitrate administration was studied. Mucosal uptake of bismuth (mean +/- SEM nmol/g protein) by gastric fundus (8.85 +/- 1.0) and antrum (7.23 +/- 1.50) was similar, but was significantly less than duodenum (19.2 +/- 3.7, p less than 0.05), jejunum (26.9 +/- 2.4, p less than 0.001) or ileum (22.4 +/- 2.2, p less than 0.001). Bismuth concentrations in antral and duodenal mucosae fell progressively over 72 hours to approximately 10% of initial concentrations (p less than 0.02). Subcellular fractionation studies of colloidal bismuth subcitrate treated duodenal enterocytes showed a brush border membrane and cytosolic localisation. These data suggest that some gastrointestinal mucosal uptake of bismuth occurs in colloidal bismuth subcitrate treated rats.

Activities and subcellular localizations of enzymes implicated in gastroduodenal bicarbonate secretion

Analytical subcellular fractionation of tissue whole homogenates and microanalysis of organelle marker enzymes were used to study the activity and subcellular localization of enzymes implicated in HCO3 secretion in rat duodenal and gastric antral mucosae. The following organelles, characterized by their marker enzymes, were located in the density gradients: cytosol (lactate dehydrogenase), plasma membrane (5'-nucleotidase), peroxisomes (catalase), mitochondria (succinate dehydrogenase), endoplasmic reticulum (Tris-resistant alpha-glucosidase), lysosomes (N-beta-acetylglucosaminidase), and brush-border membrane (Zn2+-resistant alpha-glucosidase and alkaline phosphatase). Compared with gastric antrum, rat duodenal mucosa contained over twice the activity of HCO3-ATPase and of Na+-K+-ATPase but less than one-tenth the activity of carbonic anhydrase. Duodenal HCO3-ATPase activity was observed in both mitochondrial and brush-border membrane fractions, whereas antral HCO3-ATPase activity was confined to mitochondria. Na+-K+-ATPase activity was found largely in the basolateral membrane (duodenum) and plasma membrane (antrum). In both tissues carbonic anhydrase activity was localized to the cytosolic fraction. These observations offer further evidence that differing biochemical mechanisms underlie HCO3 secretion by gastric and duodenal epithelia.

Mucosal enzyme activities, with special reference to enzymes implicated in bicarbonate secretion, in the duodenum of rats with cysteamine-induced ulcers

1. Duodenal mucosa was collected from control rats and from animals which had received cysteamine, cysteamine plus cimetidine or pentagastrin. Animals which received cysteamine with or without cimetidine developed acute duodenal ulcers. Cysteamine treatment resulted in gastric acid hypersecretion, which was largely abolished by concurrent cimetidine administration. 2. Activities of enzymes implicated in bicarbonate secretion, HCO3--activated ATPase, carbonic anhydrase and Na+ + K+-activated ATPase, were measured in the duodenal mucosa of control rats and animals 24 h after subcutaneous administration of cysteamine. Assays of these enzymes in duodenal mucosal homogenates from animals with cysteamine-induced ulcers showed significant decreases in HCO3--activated ATPase and carbonic anhydrase activities compared with controls. 3. Alkaline phosphatase activity also fell significantly in the cysteamine-treated animals, and possibly reflects the HCO3---activated ATPase activity in the brush-border membrane. In contrast, activities of other marker enzymes from the brush-border membrane and from several intracellular organelles were unchanged, indicating an absence of gross organelle pathology in this experimental model. 4. Similar changes in enzyme activity were not caused by treatment with pentagastrin. Administration of cimetidine with the cysteamine did not protect the animals against ulceration, and the activity of HCO3--activated ATPase was persistently decreased. However, the carbonic anhydrase activity was unaltered in this latter group, compared with controls. 5. These findings suggest that in cysteamine-induced duodenal ulceration both gastric acid hypersecretion and impaired duodenal resistance occurs. It is suggested that decreased activities of key enzymes implicated in HCO3--secretion may reflect the biochemical basis for the decreased mucosal resistance.