Undue Prolongation Research Articles

Abstract 193: Angiograms to assess brain death versus pentobarbital coma mimic in severe traumatic brain injury.

Introduction We hypothesized that computed tomography angiography and conventional catheter‐guided angiography (CTA & DSA) would be able to accurately distinguish prolonged total areflexic coma induced by pentobarbital (PTB) from true progression to death by neurologic criteria (DNC) in patients with traumatic brain injuries (TBI) undergoing aggressive intracranial pressure (ICP) management. We also hypothesized that despite CTA being an imperfect tool in other cases of traumatic brain injury mimicking brain death, CTA helps triage which patients would benefit from resource‐intensive DSA as a part of their DNC evaluation. Methods We present a retrospective case series of three patients with severe TBI, treated with PTB coma as part of refractory ICP treatment. Patients displayed clinical and electroencephalographic findings that mimicked DNC. These clinical cases highlight the contributions of adjunct therapies ‐ propofol, midazolam, fentanyl, paralytics and therapeutic temperature management (TTM) ‐ and their exacerbating effects of PTB resulting in brainstem areflexia. In these cases, transcranial doppler (TCD) was used in addition to CTA to determine DNC. We also present a retrospective case series of three false negative CTAs in open or closed skull injuries undergoing DNC evaluation. Results This case series highlights the challenge in clinical decision‐making when managing severe TBI with high‐dose PTB. These victims have prolonged sedation from PTB enhanced by adjunctive therapies on top of the TBI‐related coma, resulting in total areflexic coma. They are also at risk of truly progressing to DNC from herniation or brainstem ischemia despite neurocritical care. Our findings suggest that imaging is key to distinguish true progression to DNC versus areflexic mimic. We used TCD to screen for abolished perfusion which then suggested the need for CTA to demonstrate cerebral circulatory arrest (CCA). We escalated to DSA as a formally accepted BDAT per the 2023 AAN guidelines. Other options for BDAT such as SPECT and EEG are less well suited in this TBI population with PTB coma. Conclusions: This study reaffirms the limitations of TCD and CTAs, especially in open skull cases, but their useful role for stewardship towards the proper and judicious choice of a brain death ancillary test (BDAT). The differentiation of a PTB‐induced coma from DNC in TBI patients is intricate and CCA needs to be sought precisely and absolutely to guide care. This study underscores the importance of understanding progression on imaging and the role for screening with TCD and CTA. The 2023 AAN guidelines on DNC posit DSA as the sole acceptable BDAT in these cases. We recommend serial TCD monitoring and deliberate reassessment post‐PTB washout to navigate potential misdiagnosis of DNC. In cases with unrealistic waiting periods, CTA followed by DSA, both with a focus on the brainstem and with venous scrutiny using French scoring systems, seems most appropriate. Our insights seek to inform clinical practice and guard against premature cessation or undue prolongation of aggressive care. We propose to study the difference between CTA and DSA with a brainstem venous focus, as DSA remains resource‐intensive and more dangerous for fragile ICU patients.

CONVERSION TO OPEN CHOLECYSTECTOMY - A SAFE ALTERNATIVE, NOT A FAILURE!

Background: Understanding factors that predict conversion in laparoscopic cholecystectomy (LC) to an open procedure is important as it allows better patient selection, preparation, operating list planning, referral, counseling and lowers the threshold for a safe conversion, thereby minimizing undue prolongation of attempts at laparoscopic completion and inadvertent complications.Methods: Records of 1010 consecutive patients who were taken up for LC, at a tertiary care teaching institute in northern India, were reviewed retrospectively. Preoperative and intraoperative characteristics of patients who underwent a successful LC were compared with those who required conversion to open surgery.Results: The conversion rate was 7.5% (76 patients). The most common reason for conversion was the inability to define the ‘Critical view of safety’ in 48, (63%) of patients. Other reasons included dense peri-cholecystic 9 (12%) and intra-abdominal 8 (11%) adhesions, suspicion of bile duct injury 4 (5%) or malignancy 3 (4%). Prior upper abdominal surgery, intraoperative finding of a contracted and thick-walled gallbladder (GB), empyema GB, Mirizzi’s syndrome, cholecysto-enteric fistula, and a prior endoscopic common bile duct stone clearance were significant predictors of conversion. Xanthogranulomatous cholecystitis was found more commonly (43% vs 5%) in the conversion group.Conclusion: Conversion to an open procedure during LC should always be treated as an integral component of sound judgement to achieve the safest outcome in a particular patient. Due consideration of pre-operative and intra-operative factors predictive of a higher chance of conversion assists pre-operative patient preparation and counseling as well as surgical planning, conduct and mentoring of residents-in-training.

A comparative study to evaluate the optimum intubating dose of rocuronium bromide versus succinylcholine chloride as an ideal intubating muscle-relaxing agent

Background: Rocuronium bromide is a new amino steroidal neuromuscular blocking agent which is structurally related to vecuronium and its onset time and intubating conditions are comparable with succinylcholine and without the undesirable side effects. Aims and Objectives: This study was planned to evaluate the ideal intubating dose of rocuronium bromide by comparing intubating conditions achieved by its different doses of rocuronium bromide and to consider rocuronium as an ideal intubating muscle relaxing agent, in place of succinylcholine chloride for elective long surgeries. Materials and Methods: This study was conducted on 120 patients who fulfilled the eligibility criteria. These patients were randomized into four groups of 30 each by block randomization technique. Each group received rocuronium bromide 0.6 mg/kg, 0.9 mg/kg, 1.2 mg/kg, and succinylcholine chloride 1 mg/kg, respectively. Results: Out of all the three doses of rocuronium bromide 0.9 mg/kg produced a similar intubating condition as succinylcholine chloride in the dose of 1 mg/kg without undue prolongation of the neuromuscular blockade. Conclusion: Rocuronium bromide can be used as an alternative to succinylcholine as an ideal intubating muscle relaxing agent.

Clinical Experience of a Smart Articulating Digital Device for Transanal Minimally Invasive Surgery.

The constrained access associated with transanal minimally invasive surgery has led surgeons to deploy robotic-assisted platforms to offset inherent maneuverability limitations and, perhaps, skills deficits. A handheld, powered 5-mm lightweighted laparoendoscopic electromechanical digital device (HandX, HumanXtensions, Israel) with hardware and software components that convert surgical hand movements precisely to the instrument's articulating tip and enable robotic transanal minimally invasive surgery with full tip roticulation for hook diathermy and suturing. After bench and biomedical model training, HandX was used in 3 transanal minimally invasive surgery procedures (2 male patients and 1 female patient, mean age 66.3 years). The rectal lesions averaged 30 mm in maximum dimension and were located posteriorly (n = 2) and laterally (n = 1) a mean of 3 cm from the anal verge. Standard transanal minimally invasive surgery setup and instrumentation (Gelport Path, Applied Medical with Airseal, and Conmed) were used, adding the HandX device for circumferential lesion marking and hemostatic full-thickness excision as well as defect suturing where appropriate. All procedures were completed without undue prolongation (operating times <1 hour) despite nuisance hemorrhoidal bleeding in 1 patient. All lesions were fully excised, with 2 being T1 cancers and 1 tubulovillous adenoma with high-grade dysplasia. All patients were discharged within 48 hours postoperatively (1 experienced secondary hemorrhage on postoperative day 5). HandX capably facilitated endoscopic robot-like instrument movement for transanal minimally invasive surgery without disrupting workflows. With time dedicated to instrument understanding and training, HandX increased dexterity with a small operating room footprint and may offer greater cost-effectiveness than other platforms.

Medical aid in dying: A foreseen decisive role for the specialized nurse practitioner in Quebec

The legalisation of the practice of euthanasia is gaining momentum worldwide. This paper dresses the evolution of the legalisation and development of the practice of euthanasia – medical aid in dying (MAiD) – in Canada and especially in the province of Quebec to provide understanding and guidance for health care practitioners, administrators and a larger audience. This literature review explores the phenomenon of the increasing practice of MAiD in the province of Quebec (Canada) and its possible extension into practice by specialised nurse practitioners (SNPs), it also addresses the history and issues of the practice of MAiD in this context. The analysis made it possible to define three themes that make up this phenomenon, namely a) MAiD in Canada: Implementation of the Role of NPs; b) Growing demand for MAiD in Quebec’s province; c) Issues Related to a Possible Practice of MAiD by SPNs in Quebec. Results show the rising of MAiD practised in Canada and, in Quebec, especially for an aging population and those struggling with terminal illness in order to avoid undue prolongation of suffering at the end of life. However, access to end-of-life care (EoLC) and MAiD is undermined by a shortage of doctors, bureaucratic debacles, a lack of interdisciplinary cohesion and practice and, the geographical remoteness of patients. This study also highlights the modest field of research and investigation in this specific area of practice and the need for explicit teaching about the topic of the practice of MAiD for health professionals. Finally, results show that in order to remedy this problems, the governments of Canada and Quebec and various professional orders, namely those of nurses, physicians and pharmacists, have come together to promote access to MAiD by proposing a practice project for SNPs duly trained at Master degree.

EVALUATION OF INTRANASAL MIDAZOLAM AS PREANESTHETIC MEDICATION FOR BRIEF PEDIATRIC SURGICAL PROCEDURES

Background: Operation theatres environment, surgery and anesthesia causes stress and anxiety. This can cause psychological disturbances especially in children. Sedative and anxiolytic premedication have been used to prevent such outcomes.Intranasal route is least traumatic and easily accepted.Intranasal midazolam has been used for premedication in children. Objectives:The study was undertaken to evaluate the efcacy of intranasal midazolam as premedication with regard to degree of sedation,ease of parental separation, response to venepuncture,response to induction,post anesthesia recovery charecteristics and side effects if any. Methods: A prospective comparative study was conducted in the Department of anesthesia viswabharathi medical college penchikalapadu, kurnool from November 2021 to may 2022 children aged between 3 - 6 years, of either sex belonging to ASA Grade I &amp; II posted for elective surgeries were selected randomly and prospective study was done by dividing them into 3 groups. Group NS: Children received 4.mI/kg of Normal Saline ,Group M1:Children received 0.2mg/kg of intranasal midazolam, Group M2: Children received 0.3mg/kg of intranasal midazolam. The statistical software, namely SPSS 16.0 and WINKS SDA 6 were used for the analysis of the data and Microsoft Word and Excel have been used to generate graphs, tables etc. : All the groups were comparable in age,sex,weight and ASA distribution.In midazolamResults M1 group 24(80%),in M2 group 22(65%) the children were dated.In midazolam M1 group,at 10minutes,parental separation in 27(90%).In M2 group,parental separation in 25(75%) children was much easier compared to 4(13.3%) in NS group.Response to venepuncture was more satisfactory in both midazolam groups than normal saline. Response to mask placement was also good in midazolam groups. There was no undue prolongation of recovery time in all the groups. : The study shows that intranasal midazolam 0.2mg/kg administered 15min prior toConclusion induction in children of 3-6years of age produces satisfactory level of sedation,ease of separation from parents, decreased discomfort associated with venepuncture with better mask acceptance. No signicant hemodynamic changes throughout the procedure.

Communication with relatives on prognosis of critically ill patients

Most patients admitted to the intensive care unit are unable to participate in decisions relating to their care. Therefore, physicians have to inform relatives on the condition of the patient, his evolution and the estimated prognosis. Numerous studies have shown that relatives commonly have inaccurate expectations of the patient’s prognosis, due to either misunderstanding of oral information by the physicians and/or overly optimistic beliefs. This may lead to undue prolongation of an ICU stay in the case of a poor prognosis. Several methods have been proposed in order to align relatives with the estimation of the patient’s prognosis by the physicians. The use of visual tools, added to oral information seems beneficial. Moreover, communication with relatives on the prognosis has to convey support and empathy.

Study on Menorrhagia: Correlation with Fibroids

Background: Excessive menstrual bleeding called menorrhagia is a common presentation of females seeking medical attention. Normally there is considerable variation in menstrual cycle length, duration and flow.&#x0D; Objective: To find out the assocation of fibroids in patients presenting with menorrhagia.&#x0D; Materials and Methods: This cross-sectional prospective study was done from January to June 2013 among the female patients admitted in the department of Gynaecology &amp; Obstetrics in Dhaka Medical College &amp; Hospital. Patients presented with the complaints of menorrhagia and treated by surgical management were included.&#x0D; Results: Total 96 patients were included. The age range was 28–49 years with mean age 41.08 ± 5.174 years. In 92 (46.5%) patients excessive per vaginal bleeding was noted. Pain during menstruation was another major complaint (45, 46.5%). Lower abdominal heaviness was reported in 32 patients (16.2%). In about half of the patients (49%) uterine fibroid was diagnosed. In 29 patients (30.2%) adenomyosis was the finding. Out of 47 fibroid cases 39 (83%) had per vaginal bleeding history. Only 10 patients without fibroid experienced pervaginal bleeding. Chi-squared test was done to see whether there was any association between these two variables and the result was highly significant (p&lt;0.001).&#x0D; Conclusion: As medical treatment is disappointing and surgery is the mainstay of treatment of menorrhagia caused by fibroids, diagnosis should be confirmed by different imaging techniques. Advancement in the field of imaging like saline infusion sonohysterography and hysteroscopy helps greatly to diagnose submucous fibroids and save patients from undue prolongation of medical treatment.&#x0D; J Enam Med Col 2020; 10(2): 99-103

Effect of laparoscopy on liver enzymes

Background: Laparoscopic procedures have gained popularity in recent days because of advantages like small incision, less postoperative pain and discomfort, short hospital stay, early ambulation and early discharge. Very few studies are available to correlate Laparoscopic Surgeries and liver enzyme elevation. This effect may be due to either CO2 pneumoperitoneum, diathermy extruding liver, injury to branch of the hepatic artery or general anesthesia. This study was done to evaluate the changes in liver enzymes pre-operatively and post-operatively following laparoscopy.Methods: This prospective study included 103 patients who underwent various laparoscopic surgeries over a period of 2 years in Bharati Hospital &amp; Research Centre, Pune, India. Serum AST, ALT and bilirubin levels were measured preoperatively and on post-operative day 1 and post-operative day 3. Patients with coexisting liver disease, Patients on long term use of hepatotoxic drugs, patients who developed complications such as CBD injury, obstruction, infection, leakage and high grade fever during surgery and in the post-operative period were excluded.Results: All laparoscopic procedures cause a transient elevation of serum bilirubin and liver enzymes. Elevation in the liver enzymes correlated directly with the duration of pneumoperitoneum. Elevation in the serum bilirubin but doesn’t correlates with the duration of pneumoperitoneum. These elevations do not have clinical significance in patients with normal hepatic function preoperatively.Conclusions: Duration of laparoscopic procedure should be kept to minimum and undue prolongation should be avoided. Decision to convert the operation to open surgery from a laparoscopic surgery should be prompt.

Ethical Issues concerning Legislation in Late-Term Abortions in India.

Late-term abortions (after 20 weeks of gestation) are an issue of immense debate in India, where the Medical Termination of Pregnancy Act, 1971 permits abortions only up to 20 weeks of gestation. In special situations, such as pregnancy arising out of rape especially in the case of minors and the late diagnosis of congenital anomalies, there are no clear guidelines on the legal protocol that is to be followed, often resulting in a lack of consistency in terms of legal decision-making, as well as undue prolongation of legal procedures. The Medical Termination of Pregnancy Act prohibits late-term abortions on the basis of personhood and viability of the foetus, to reduce sex-selective abortions and as it considers such abortions to be unsafe. However, a legal prohibition of late-term abortions does not prevent them, and this has led to a surge in the number of illegal, unsafe abortions that are detrimental to the health of women. There is also physical, mental and financial distress to women who are forced to continue their pregnancy, coupled with a lack of governmental support for the same. In comparison of India's abortion laws with Singapore's, which are more liberal, and Philippines, which are more restrictive, liberalisation of abortion laws appears to have a better outcome in reducing the incidence of unsafe abortions. This paper argues that the way forward is to liberalise the laws in terms of not only extending the gestational limit to at least 24 weeks but also making exceptions allowing no gestational limit in special cases that warrant them, such as rape victims and late foetal anomalies. The laws, drafted and implemented in consultation with medical professionals in the field, must also be lucid and not leave any room for misinterpretation by courts and health care providers.

Foeto-placental parameters in normal pregnancy and factors affecting them.

The aim of this study was to evaluate foeto-placental (F/P) parameters, namely foetal birth weight, placental weight (PW) and F/P weight ratio, in normal pregnancy and factors affecting them. A retrospective study was conducted on labour ward data obtained over a period of 3 years (2015-2017). Only deliveries above 28-week gestational age which met other selection criteria were included in the study. Their sociodemographic parameters, PW, foetal birth weight, foetal outcome and Apgar scores were extracted from the delivery registers. The F/P weight ratio was calculated from the values obtained. All data collected were subjected to statistical analysis using SPSS version 20. The mean age ± standard error of mean of parturient was 31.84 ± 0.18 years. A larger proportion, 1455 (80.7%) of the women were booked. The mean gestational age ± standard deviation at delivery was 37.81 ± 2.72 weeks. Foetal weight (FW), PW and F/P weight ratio rise progressively with advancing gestational age in normal pregnancy, the FW rising faster than the placenta which gains weight slowly. The F/P ratio rises steadily initially and then abruptly from 42-week gestational age as the foetus outgrows the placenta, after which there is a sharp decline from 43-week gestational age. FW, PW and F/P ratio are significantly affected by gestational age and booking status (P = 0.000). Parity and foetal sex were found to have significant influence on FW alone (P = 0.026 and P = 0.000, respectively). This study clarifies the need to avoid undue prolongation of pregnancy beyond 42 weeks to avert adverse consequences which may be related to the differential growth in the foetus and placenta.

Intraoperative and Postoperative Administration of Dexmedetomidine Reduces Anesthetic and Postoperative Analgesic Requirements in Patients Undergoing Cervical Spine Surgeries.

Early recovery from anesthesia and avoidance of analgesics with respiratory depressant properties are vital for maintenance of extubated airway in cervical spine surgeries. The current study investigated the role of dexmedetomidine as an anesthetic sparing agent and as a sole postoperative analgesic in these cases. Sixty adult patients undergoing cervical spine surgeries were randomized into 2 groups. Group D received intravenous dexmedetomidine infusion 0.5 μg/kg/h throughout the surgery after a loading dose of 1 μg/kg over 10 minutes. Postoperatively, dexmedetomidine infusion was continued at 0.2 μg/kg/h for 24 hours. Group C received a volume-matched bolus and infusion of 0.9% saline. Intraoperative anesthetic requirement, time to recovery, and discharge were recorded. Patients were observed for rescue analgesic requirements for 24 hours after surgery. Hemodynamic stability, sedation scores, and pain scores were assessed for 48 hours after surgery. There was significant reduction in intraoperative anesthetic requirement in group D (P<0.001). Although sedation scores and recovery criteria were comparable, pain scores were significantly lower in group D compared with group C for first 24 hours postoperatively at all corresponding times. The mean pain-free period after surgery was significantly longer in group D (1460.67±517.16 min) with significantly less rescue analgesic requirement during 24-hour postoperative period (P=0.018) compared with group C (98.17±81.20 min). Hemodynamic parameters were maintained within clinically normal range during study period. Dexmedetomidine lowered the anesthetic requirement with clinically permissible hemodynamic variations without undue prolongation of recovery time. Postoperative dexmedetomidine infusion provided effective analgesia without excessive sedation in patients undergoing cervical spine surgeries.

English

English

Beliefs, Values and Morals: The Philosophical Underpinnings of Dysthanasia

In medical practice, the treatment and prognosis in the end of life has associated to ethical dilemmas, which are established in conformity with individual or collective beliefs and values. Dysthanasia from Greek, means to make death difficult, and it is currently an ethical problem with significant consequences. Considering that death itself has two moments, the process of death and the moment of death, dysthanasia is the undue prolongation of the process of death with the help of technological devices that allows the life sustaining procedures. Although it is through the technological advances that the moment of death can be delayed, it is the beliefs and values that are deep rooted in the sub conscience of the physicians that are responsible for the demeanor of end of life ethical dilemmas. Beliefs and values when encompassed in areas like phenomenology of knowledge, dialectic of technology, conflict of values and existentialism and metaphysics, can somehow explain this issue that is current, emerging and compelling.

Radiotherapy for Breast Cancer in Countries with Limited Resources: Program Implementation and Evidence-Based Recommendations

Radiotherapy is an essential part of the multimodality treatment of breast cancer. Applying safe and effective treatment requires appropriate facilities, staff, and equipment, as well as support systems, initiation of treatment without undue delay, geographic accessibility, and completion of radiotherapy without undue prolongation of the overall treatment time. Radiotherapy can be delivered with a cobalt-60 unit or a linear accelerator (linac). In early stage breast cancer, radiotherapy is an integral part of breast-conserving treatment. Standard treatment includes irradiation of the entire breast for several weeks, followed by a boost to the tumor bed in women age 50 years or younger or those with close surgical margins. Mastectomy is an appropriate treatment for many patients. Postmastectomy irradiation with proper techniques substantially decreases local recurrences and improves survival in patients with positive axillary lymph nodes. It is also considered for patients with negative nodes if they have multiple adverse features such as a primary tumor larger than 2 cm, unsatisfactory surgical margins, and lymphovascular invasion. Many patients present with locally advanced or inoperable breast cancer. Their initial treatment is by systemic therapy; after responding to systemic therapy, most will require a modified radical mastectomy followed by radiotherapy. For those patients in whom mastectomy is still not possible after initial systemic therapy, breast and regional irradiation is given, followed whenever possible by mastectomy. For patients with distant metastases, irradiation may provide relief of symptoms such as pain, bleeding, ulceration, and lymphedema. A single fraction of irradiation can effectively relieve pain from bone metastases. Radiotherapy is also effective in the palliation of symptoms secondary to metastases in the brain, lungs, and other sites. Radiotherapy is important in the treatment of women with breast cancer of all stages. In developing countries, it is required for almost all women with the disease and should therefore be available.

In-water resuscitation: a pilot evaluation

Introduction: The first and most important treatment for the apnoeic drowning victim is the rapid alleviation of hypoxia by artificial ventilation. Recent studies have suggested that commencing resuscitative efforts with the victim still in the water may be beneficial. The aim of this pilot study was to evaluate the feasibility and efficacy of in-water unsupported rescue breathing. Methods: Three lifeguards were taught how to perform in-water unsupported rescue breathing. Ventilation volume, inflation duration were recorded from a modified Laerdal resuscitation manikin. The rescue duration was recorded and compared to a rescue undertaken without in-water resuscitation. Results: The three lifeguards performed between seven and nine ventilations during each simulated rescue. This gave average inflation volumes for each lifeguard of 711 ml (S.D. 166), 750 ml (S.D. 108), 629 ml (S.D. 182) and average inflation duration of 0.8 s (S.D. 0.3), 0.9 s (S.D. 0.2) and 0.6 s (S.D. 0.1). The rescue duration was increased from an average time of 1 min 10 s to 1 min 24 s by performing in-water resuscitation. Conclusion: This study has demonstrated the feasibility and potential efficacy of in-water unsupported rescue breathing with a victim in deep water. Furthermore, the technique was not associated with an undue prolongation of the rescue duration over a 50 m rescue. In circumstances where the trained lifeguard finds themselves with an apnoeic victim in the water, with no buoyant rescue aid available, they may consider the application of in-water, unsupported rescue breathing, especially if recovery to dry land is likely to be delayed. The effectiveness of this technique, however, remains to be proven in the open water environment.

Avoiding premature closure in sequential diagnosis

An important aspect of diagnostic reasoning is the ability to recognise when there is sufficient evidence to enable a working diagnosis to be made and thus avoid the unnecessary risks and costs of further testing. On the other hand, the reasoner must be careful to avoid the error, known as premature closure, of accepting a diagnosis before it is fully verified. In the absence of a more rigorous approach to verification, a pragmatic approach adopted in many programs for sequential diagnosis is to discontinue testing when the probability of the leading hypothesis reaches an arbitrary threshold. Experimental results are presented to illustrate the potential unreliability of this approach. A more reliable way to avoid premature closure is to discontinue testing only when the lower bound for the probability of the leading hypothesis reaches an acceptably high level. For example, a lower bound of 70% means that its probability can never be less than 70% regardless of any evidence that further testing may reveal. Another reason to discontinue testing may be that further evidence can at best increase the probability of the leading hypothesis by a small amount. For example, if the probability of the leading hypothesis is 72%, with a lower bound of 65% and an upper bound of 75%, further testing may be difficult to justify. As these examples illustrate, a termination strategy informed by upper and lower bounds for the probability of the leading hypothesis may help to avoid both premature closure and undue prolongation of the testing process. Finding upper and lower bounds for the probability of a diagnostic hypothesis as each new piece of evidence is obtained is feasible by existing techniques only when the number of remaining tests is small. However, new techniques are presented which can often produce a dramatic reduction in the computational effort required to find the upper and lower bounds. Based on the independence Bayesian framework, the theory presented extends a probabilistic model of hypothetico-deductive reasoning designed to enable programs for sequential diagnosis in medicine to emulate the reasoning processes of human diagnosticians.

Erythropoiesis in primary (idiopathic) osteomyelofibrosis: quantification, PCNA-reactivity, and prognostic impact.

In 64 patients with primary (idiopathic) osteomyelofibrosis (OMF), a morphometric analysis has been performed on bone marrow trephine biopsies following sequential double-immunostaining with monoclonal antibodies against proliferating cell nuclear antigen (PCNA) and erythroid precursor cells (glycophorin C). The purpose of this study was to quantify erythropoiesis and its PCNA-staining capacity and, further, to determine the impact of these parameters for the development of anemia and for prognosis. In comparison with a control group (15 patients), a significant reduction in the number of erythro-normoblasts could be demonstrated, associated with an increase in PCNA-labelling. Moreover, significant correlations between the amount of nucleated erythroid marrow cells and degree of anemia (hemoglobin level, hematocrit, erythrocyte count) and survival could be calculated. Adverse relationships were assessed between number of erythroid cells, thrombocyte count, and spleen size, and also argyrophilic (reticulin/collagen) fiber density. These interactions were thought to reflect the biological behaviour of the disease process, i.e., the progression or extent of myeloid metaplasia. Our findings support ferrokinetic studies suggesting erythroid hypoplasia as one of the major causes of anemia in OMF. The remarkable high PCNA-labelling index of the macrocytic-megaloblastoid appearing erythropoiesis is probably caused by an overexpression of this marker protein. A comparative evaluation of Ki-67 antigen immunostaining in splenic tissue (myeloid metaplasia) and of the PCNA-labelling in pernicious anemia lend support to the assumption of an undue prolongation of the S-phase generated by secondary folate (hematinic) deficiency.

Temporary AV-shunt for auxiliary microvascular anastomoses of the TRAM or VRAM flap in breast reconstruction ?the turbo-charged flap

Despite careful dissection of the inferior epigastric vessels, pedicle length is usually found to be uncomfortably short, often necessitating the interpositioning of vein grafts when an axillary anastomosis is to be performed. Creating a temporary cephalic vein loop to either the circumflex scapulae or the pectoral branch of the acromioclavicular artery greatly facilitates the microvascular anastomoses without undue prolongation of operating time. Auxiliary microvascular anastomoses of the more dominant inferior epigastric vessels is proposed as an additional safeguard in cases where a disturbed bloodflow pattern after transpositioning the pedicled island TRAM or VRAM flap is found.

Prolongation of Pancuronium-Induced Neuromuscular Blockade by Intravenous Infusion of Nitroglycerin

Based upon clinical observation of undue prolongation of pancuronium-induced blockade in the presence of intravenous infusion of nitroglycerin, neuromuscular blockades produced by pancuronium, succinylcholine and d-tubocurarine were studied in 51 cats using the sciatic-gastrocnemius nerve-muscle preparation. Pancuronium-induced blockade was found to be significantly prolonged (P less than 0.1) in the presence of a nitroglycerin infusion of 1 microgram/kg/min (65 vs. 127 min). Less, but still significant, prolongation occurred when nitroglycerin, 0.5 microgram/kg/min, was infused. The intravenous infusion of nitroglycerin must be started prior to the pancuronium injection for the block to be prolonged. Neuromuscular blocks produced by succinylcholine and d-tubocurarine were not altered by nitroglycerin. In experiments using the isolated rat diaphragm preparation, the depth of pancuronium-induced block was found not to be changed by nitroglycerin, suggesting an effect of nitroglycerin on the process of recovery from blockade. These findings indicate a selective pancuronium-nitroglycerin interaction.