Sediment-bound metals as indicators of anthropogenic change in estuarine environments

Sedimentary metal indicators were used to assess the environmental 'health' of 38 estuaries on the central Australian east coast. Unlike many environmental indicators, the mean enrichment quotient (MEQ) provides the pristine condition and magnitude of anthropogenic change in estuarine condition, not confounded by natural spatial and temporal variation. MEQ is the mean normalised surficial concentration of Cu, Pb and Zn divided by their normalised background concentration. MEQs, identified from an extensive sedimentary database (n=2269), were used to derive a Metal Enrichment Index (MEI) comprising five impact categories. Population density and proportion of urbanised catchment were consistent with increased sedimentary metal concentrations, whereas estuarine sensitivity and metal enrichment were poorly correlated. No correlation was established between metal enrichment and estuary type or sedimentary facies. MEI can be used as a tool to meet the needs of policy-makers and estuarine managers by providing a tool by which human-induced change may be measured.

Systematic review and meta-analysis of observational studies on the prevalence of fractures in coeliac disease

BACKGROUND/AIMS

Evidence of an increased bone fracture risk in coeliac disease is on debate. Our aim was to review systematically the current published information on fractures in coeliac disease and to perform a meta-analysis.

METHODS

Case-control and cohort designs were identified by searching MEDLINE (1966-April 2007) and LILACS (1982-April 2007). Participants were adult coeliac disease patients of any sex and the outcome measure was the presence of any fracture. Studies were screened for inclusion by two authors who independently extracted the data. Methodological quality was assessed using the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology Statement) recommendations. Data were analysed using the RevMan Analyses statistical package in Review Manager (version 4.2.8) and reported as pooled odds ratio using a random effect model. Heterogeneity was investigated (standard chi(2) test) and sensitivity analysis was performed based on the reported quality and design type.

RESULTS

While 60 of 405 studies met the initial screening criteria, only 8 met inclusion criteria after detailed review. These studies evaluated a total of 20,955 coeliac disease patients having 1819 (8.7%) fractures and 96,777 controls with 5955 (6.1%) fractures (pooled odds ratio=1.43; 95% confidence interval 1.15-1.78) with considerable heterogeneity among studies (p<0.00001).

CONCLUSIONS

Our meta-analysis confirms a significant association between bone fractures and coeliac disease. However, qualitative and quantitative differences among studies were evident. Further research is necessary to investigate the relevance of this heterogeneity.

Decision analysis: an aid to the diagnosis of Whipple's disease

BACKGROUND

Diagnosis of Whipple's disease, a rare systemic infection affecting predominantly the small bowel, is based on the identification of the bacterium Tropheryma whipplei.

AIMS

To make explicit diagnostic uncertainties in Whipple's disease through a decision analysis, considering two different clinical scenarios at presentation.

METHODS

Using appropriate software, a decision tree estimated the consequences after testing different strategies for diagnosis of Whipple's disease. Probabilities and outcomes to determine the optimum expected value were based on MEDLINE search.

RESULTS

In patients with clinically-predominant intestinal involvement, diagnostic strategies considering intestinal biopsy for histology (including appropriate staining) and the polymerase chain reaction testing for bacterial DNA were similarly effective. In case of failure of one procedure, the best sequential choice was a polymerase chain reaction analysis after a negative histology. Of the five strategies tested for cases with predominant focal neurological involvement, the stereotaxis cerebral biopsy evidenced the highest expected value. However, using quality-adjusted life-years considering the morbidity of methods, intestinal biopsy for PCR determination was the best choice.

CONCLUSIONS

In patients with Whipple's disease having predominant digestive involvement, intestinal biopsies for histology should be indicated first and, if negative, a bacterial polymerase chain reaction determination should be the next option. Although the molecular polymerase chain reaction assessment of cerebral biopsies has the highest diagnostic yield in neurological Whipple's disease, its associated morbidity means that analyses of intestinal samples are more appropriate.

[Incidental diagnosis of an ostium-secundum-type interatrial communication during coronary surgery]

Preoperative assessment of a 73-year-old woman scheduled for coronary revascularization revealed signs of severe disease in three coronary vessels, mild mitral valve insufficiency, moderate tricuspid insufficiency and moderate-to-severe pulmonary hypertension, with preserved left ventricular function. During surgery pulmonary artery catheter measurements confirmed pulmonary hypertension and the presence of very high cardiac output, leading to suspicion of atrial septal defect. Peripheral vein and right atrial blood samples revealed a sudden increase of 23 mm Hg in PO2 and of 22% in oxygen saturation. Finding the opening in the wall of the right atrium gave diagnostic confirmation of an ostium secundum defect 3 cm in diameter. The defect was closed and the coronary vessel bypasses were created. Upon weaning from extracorporeal circulation, the sudden oximetric increase was seen to have disappeared and pulmonary artery pressures had decreased. Postoperative course was satisfactory, with normal sinus rhythms alternating with episodes of atrial fibrillation. We stress the importance of invasive hemodynamic monitoring and transesophageal echography during heart surgery to confirm diagnoses that have not been established during preoperative assessment.

[Efficacy of a single dose of urapidil for preventing arterial hypertension during the pre-bypass period in coronary surgery]

OBJECTIVES

To assess the effect of a single prophylactic dose of urapidil for arterial hypertension during the period before start of extracorporeal circulation.

PATIENTS AND METHODS

Forty-four patients with good ventricular function (ejection fraction < 40%) scheduled for coronary surgery were enrolled for prospective study. The patients were randomly assigned to receive 0.5 mg/kg of urapidil (group U, n = 22) or nothing (group N, n = 22) 3 min before skin incision. If hypertension developed sodium nitroprusside was administered, starting with a dose of 0.5 microgram/kg/min. Monitoring of arterial pressure, heart rate and ST segment (DII and V5) was continuous. The study ended with cannulation of the aorta.

RESULTS

The demographic features, cardiovascular history, medication and duration of surgery were comparable in the two groups. Six patients in group U (27%) and 19 in group N (86%) developed arterial hypertension (p < 0.001), the duration of which was 2.23 +/- 4.49 min in group U and 9.64 +/- 9.7 min in group N (p < 0.05). Arterial hypotension was observed in 13 group U patients and 7 group N patients (NS). No significant differences in duration of tachycardia, bradycardia or myocardial ischemia were found.

CONCLUSIONS

The administration of a single dose of urapidil prevents arterial hypertension during the phase before extracorporeal circulation for coronary surgery and reduces the need for nitroprusside. No clinically relevant side effects are evident.

The combined effect of age and premedication on the propofol requirements for induction by target-controlled infusion

In this prospective study, we evaluated the combined influence of age and premedication on propofol requirements for the induction of anesthesia and their hemodynamic effects using a target-controlled infusion. We studied 180 patients separated into three age groups: 20-39 yr, 40-59 yr, and more than 59 yr. In each age group, patients were randomly allocated to receive either no premedication (n = 20), fentanyl (2 microg/kg) (n = 20), or midazolam (0.03 mg/kg) plus fentanyl (2 microg/kg) (n = 20). The concentration of propofol targeted for the induction was 5 microg/mL, to be reached in 2 min. The dose, time, and predicted plasma concentration of propofol at hypnosis were measured. Baseline and postinduction heart rate and arterial blood pressure were registered. Computer simulation was used to calculate the effect site propofol concentration at hypnosis. The concentration of propofol, effect site propofol concentration, time, and induction dose and their hemodynamic effect were significantly different among groups with respect to age and premedication. The combined effect of the two factors was additive, but without significant interaction. The propofol requirements were significantly less in the midazolam-fentanyl groups, regardless of age, and among the premedicated patients older than 60 yr compared with the other age groups. We conclude that the combined effect of age and premedication on the requirements of propofol for the induction of anesthesia should be considered when the concentration is targeted with a target-controlled infusion system.

[Endoscopic cholangiography in biliary tract diseases in HIV+ patients]

Biliary tract involvement in the course of the infection by HIV was first described in 1983. Since then, various opportunistic infections have been responsible of different biliary lesions, coming to a new entity called "cholangiopathy associated to HIV". Our aim was to determined the use of ERCP in the management of HIV patients with cholestasis. From August 1994 to October 1997, 11 HIV patients (8 men, 3 women, mean age 35 y.) were submitted to ERCP because of jaundice (n = 8), upper right abdominal pain (n = 8), fever (n = 6), pruritus (n = 5) and elevated alkaline phosphatase (n-10). In 7 the diagnosis of AIDS had already be made. All had hepatobiliary ultrasound and endoscopic periampullar duodenal mucosa biopsy was taken in 7. According to Cello, 4 types of radiologic lesions were considered: 1) Papillary stenosis with dilated extrahepatic biliary tract. 2) Sclerosing cholangitis (focal intra or extrahepatic stenosis and dilatations). 3) Association of types 1 and 2.4) Choledocal long stenosis in the absence of previous biliary surgery or chronic pancreatitis. Five patients (45%) had biliary abnormalities; in 3 related to HIV infection: sclerosing cholangitis (n = 2) and papillary stenosis (n = 1). Two had choledocal stones. Four had upper right abdominal pain and dilated bile ducts at ultrasound. Cryptosporidium was found in duodenal mucosa in one patient with sclerosing cholangitis and in the patient with papillary stenosis. Biliary stents were placed without sphincterotomy in 2, with relief of pain and improving of cholestasis in only one. The choledocal stones were removed endoscopically in one patient and by surgery in the other.

CONCLUSION

The ERCP is a useful method in the diagnosis and treatment of the biliary tract abnormalities associated to HIV.

[Treatment of the hypertensive response during coronary surgery: comparison of high-dose propofol to propofol with nitroprusside]

OBJECTIVE

To determine the efficacy of high doses of propofol for controlling hypertension during coronary surgery and to compared cardiovascular stability with propofol to that observed under lower doses of propofol with nitroprusside.

PATIENTS AND METHODS

Forty patients were studied prospectively. The patients had good ventricular function and were scheduled for coronary surgery, randomized to two groups. Group P (n = 20) received 0.3 mg/kg propofol plus a 10 mg/kg/h perfusion. Hypertensive responses were treated with boluses of 0.3 mg/kg of propofol and progressive increases in the perfusion dose of 2.5 mg/kg/h at intervals of 2 minutes (maximum 15 mg/kg/h). If hypertension persisted it was treated with nitroprusside. Group N (n = 20) received propofol in perfusion at a dose of 8 mg/kg/h and hypertension was controlled directly with nitroprusside. During extracorporeal circulation, the propofol dose was reduced to 3 mg/kg/h in both groups and was adjusted in response to changes in arterial pressure, with nitroprusside added as needed. We recorded the number of patients becoming hypertensive during sternotomy and mediastinal dissection, the maximum doses of propofol and nitroprusside and the time taken to achieve control of hypertension. Arterial pressure and heart rate were recorded at intervals of one minute throughout the operation.

RESULTS

Eight patients in group P and eleven in group N suffered hypertension (NS). Increasing the dose of propofol in group P controlled arterial hypertension in one patient. We found no significant differences between groups in amount of nitroprusside needed or time taken to bring episodes under control. Differences between the two groups in rates of intraoperative hypertension (65% in group P and 85% in group N) and hypotension (75% in group P and 55% in group N) and in duration of episodes were not statistically significant.

CONCLUSIONS

Using high doses of propofol rather than moderate doses in combination with nitroprusside in coronary surgery does not improve control of either hypertension or hemodynamic stability.

[Is crystalloid cardioplegia still a valid technique for myocardial myocardial protection?]

OBJECTIVES

The routine use of a cardioplegic solution for myocardial protection during the ischemic phase of cardiac surgery represents a great therapeutic advance. Two cardioplegic solutions are currently in use: crystalloid and blood solutions. As blood cardioplegia has been shown to offer superior myocardial protection, its use at present is widespread. We did a retrospective study to assess whether crystalloid cardioplegia might nevertheless continue to be useful.

PATIENTS AND METHODS

Forty patients with heart disease underwent surgery between March 1994 and March 1995, with the use of crystalloid cardioplegia (group A). Blood cardioplegia was used in 72 patients during the same period (group B).

RESULTS

There were no significant differences in clinical (age, arterial hypertension, diabetes, chronic bronchial disease, severity of angina, severity of heart disease) or surgical (emergency, percent use of the internal thoracic artery, duration of extracorporeal circulation) variables. The percentage of patients with low ejection fraction was higher in group B as a result of preoperative selection. The mean number of grafts was higher in group B than in group A (3.5% and 2.5, respectively) (p < 0.01). Postoperative results (use of inotropics, counterpulsation balloon, creatine phosphokinase, perioperative myocardial infarction or hospital mortality) were not significantly different. The percent of supraventricular arrhythmias after surgery was higher in group A than in group B (20% and 5%, respectively) (p < 0.05) and lactic dehydrogenase level was lower in group A than in group B (472 and 572 mu/l, respectively) (p < 0.05).

CONCLUSIONS

We believe that crystalloid cardioplegia continues to be a valid and effective myocardial protection technique in heart patients with preserved left ventricular systolic function.

[Diarrhea and AIDS: more complex diagnostic techniques; better therapeutic results]

During 17 months, 73 HIV-positive patients with diarrhea lasting at least for 14 days, were studied prospectively. The patients had stool specimen examinations negative for enteric pathogens, or positive for one of them, but with no response to specific treatment. All patients were subcomitted to digestive endoscopy and biopsies were taken for microbiological and histological studies. The etiology of the diarrhea could be established in 48 patients (66%). In 45, the cause was an enteric infection. There was association of 2 pathogens in 11 patients, and of 3 in 1 patient. The agents found were: Cryptosporidium (24%), MAI (16%), Giardia lambila (12%), isospora belli (5%), Shigella (5%), Salmonella (5%); Entamoeba histolytica (3%), HSV (3%), tuberculosis (2%), adherent bacteria (2%) and spirochetes (2%). In 3 patients the etiology was not infection, their diagnoses were coeliac disease, lymphoma and idiophatic colonic ulcers, respectively. In 51% of the cases only the examination of endoscopic biopsy specimens could identify the cause of the diarrhea. These results justify the use of these methods to improve diagnosis and therapeutic attempts in these patients.

Facial nerve paralysis after epidural blood patch

BACKGROUND. A 35-year-old parturient developed a unilateral facial nerve palsy after an epidural blood patch for treatment of subarachnoid-cutaneous fistula. CONCLUSIONS. Idiopathic facial paralysis and other pathogenic mechanisms are discussed. The course of the events support the suggestion that changes in subarachnoid and epidural pressures after an epidural blood patch could precipitate an injury to the 7th nerve.

[Intubation with propofol without neuromuscular blockade. Effect of premedication on fentanyl and lidocaine]

AIMS

Laryngotracheal reflexes, and possibilities of intubations following anaesthetic induction with propofol, with or without premedication and without neuromuscular blockade were evaluated. Hemodynamic parameters were also measured.

METHODS

Sixty ASA I-II patients were randomly allocated into 3 groups according to anaesthetic premedication. Group P: (placebo), 2 and 4 ml of saline 0.9%; group F, 4 micrograms/kg of fentanyl and 2 ml of saline 0.9%; group L, 4 micrograms/kg of fentanyl and 1.5 mg/kg of lidocaine 5%. Two point five mg/kg of propofol were administered and 45 seconds later intubation was attempted. Mandibular relaxation, visualization of the glottis, opening of the vocal chords, reflex reactions to laryngoscopy and intubation, time used, blood pressure and heart rate were evaluated.

RESULTS

Mandibular relaxation and visualization of the glottis were acceptable in all the patients. The aperture of the vocal chords was enough so as to carry out intubation in 65% (P), 100% (F) (p < 0.05) and 95% (L) (p < 0.05). Laryngeal reactivity significantly decreased (p < 0.001) from 40% (P) to 15% (F) and 10% (L). Tracheal reflexes decreased from 84.6% (P) to 55% (F) (p < 0.01) and 37% (L) (p < 0.001). Blood pressure and heart rate rose with intubation over the basal levels in group P and significantly decreased in groups F and L.

CONCLUSIONS

The use of propofol without neuromuscular blockade is inadequate for intubation since laryngotracheal reflexes are not suppressed. Besides, propofol does not prevent hemodynamic reactions. Premedication with fentanyl and/or lidocaine improves the responses not sufficiently to safely perform intubation.

[A bupivacaine-morphine combination by intrathecal route: correlation between pain relief and postoperative neuroendocrine response]

The purpose of the present study was to assess the repercussion of morphine injected in the intrathecal space on postoperative neuroendocrine response and the correlation with pain relief in the postop period. We studied 50 healthy patients (ASA I-II) submitted to orthopaedic surgery under general anaesthesia (N = 25) or spinal anaesthesia (N = 25). In the group under general anaesthesia we observed a hypersecretion of ADH, ACTH, cortisol and aldosterone during and after surgery. In the group un spinal anaesthesia, it was evident, on the contrary, a blockade of the neuroendocrine response during surgery, as well as an attenuation during postoperative period. Intraoperative and postoperative bleeding with spinal anaesthesia was significantly lower (p less than 0.01; p less than 0.05 respectively) than with general anaesthesia. Postoperative analgesia was excellent in group with spinal anaesthesia; the average duration of analgesia was 16.3 hours. We conclude that small intrathecal doses of morphine have beneficial effects and may be used usefulness in orthopaedic surgery.