Silent myocardial ischaemia and haemoglobin concentration: a randomized controlled trial of transfusion strategy in lower limb arthroplasty

BACKGROUND AND OBJECTIVES

Red cell transfusion is commonly used in orthopaedic surgery. Evidence suggests that a restrictive transfusion strategy may be safe for most patients. However, concern has been raised over the risks of anaemia in those with ischaemic cardiac disease. Perioperative silent myocardial ischaemia (SMI) has a relatively high incidence in the elderly population undergoing elective surgery. This study used Holter monitoring to compare the effect of a restrictive and a liberal red cell transfusion strategy on the incidence of SMI in patients without signs or symptoms of ischaemic heart disease who were undergoing lower limb arthroplasty.

MATERIALS AND METHODS

We performed a multicentre, controlled trial in which 260 patients undergoing elective hip and knee replacement surgery were enrolled and randomized to transfusion triggers that were either restrictive (8 g/dl) or liberal (10 g/dl). Participants were monitored with continuous ambulatory electrocardiogram (ECG) (Holter monitoring), preoperatively for 12 h and postoperatively for 72 h. The tapes were analysed for new ischaemia by technicians blinded to treatment. The total ischaemia time in minutes was divided by the recording time in hours and an ischaemic load in min/h was calculated. Haemoglobin levels were measured preoperatively, postoperatively in the recovery room, and on days one, three and five after surgery.

RESULTS

The mean postoperative haemoglobin concentration was 9.87 g/dl in the restrictive group and 11.09 g/dl in the liberal group. In the restrictive group, 34% were transfused a total of 89 red cell units, and in the liberal group 43% were given a total of 119 red cell units. A postoperative episode of silent ischaemia was experienced by 21/109 (19%) patients in the restrictive group and by 26/109 (24%) patients in the liberal group [mean difference -4.6%; 95% confidence interval (CI): -15.5% to 6%, P = 0.41). There was no significant difference (P = 0.53) between the overall ischaemic load in the restrictive group (median 0 min/h, range 0-4.18) and the liberal group (median 0 min/h, range 0-19.48). In those patients who did experience postoperative SMI, the mean ischaemic load was 0.48 min/h in the restrictive group and 1.51 min/h in the liberal group (ratio 0.32, 95% CI: 0.14-0.76, P = 0.011). The median postoperative length of hospital stay in the restrictive group was 7.3 days [range 5-11; interquartile range (IQR) 6-8] compared with 7.5 days (range 5-13; IQR 7-8) in the liberal group. The numbers were not large enough to conclude equivalence.

CONCLUSIONS

In patients without preoperative evidence of myocardial ischaemia undergoing elective hip and knee replacement surgery, a restrictive transfusion strategy seems unlikely to be associated with an increased incidence of SMI. A proportion of these patients experience moderate SMI, regardless of the transfusion trigger. Use of a restrictive transfusion strategy did not increase length of hospital stay, and use of this strategy would lead to a significant reduction in red cell transfusion in orthopaedic surgery. Our data did not indicate any potential for harm in employing such a strategy in patients with no prior evidence of cardiac ischaemia who were undergoing elective orthopaedic surgery.

Cirugía laparoscópica en el tratamiento de enfermedades adrenales: experiencia en 200 casos

OBJECTIVE

We report our experience in laparoscopic adrenalectomy, after adopting the laparoscopic technique for 10 years as a primary option for suprarenal surgery.

METHODS

We included 200 laparoscopic adrenal surgeries performed consecutively in 183 patients with surgical adrenal pathology between November 1994 and November 2005. Sixty-seven (36.6%) patients were male and 116 (63.4%) were female, with an average age of 49.1 years (age range 8 months to 78 years).

RESULTS

The most frequents clinical diagnosis were hyperaldosteronism (17.5%), metastatic cancer (15.8%), pheochromocytoma (15.3%), Cushing syndrome (7.1%), adrenal cyst (4.9%) and myelolipoma (2.7%). A total of 164 total adrenalectomies, 29 partial adrenalectomies and 7 marsupializations of adrenal cysts were performed. Mean surgical time was 82.6 minutes (range 25 to 240 minutes) and mean hospitalization time was 2.5 days (range 1-10 days). The size of the suprarenal gland and/or tumor varied between 1 and 14 cm (average 5.6 cm). The rate of complication was 6%. In 8 of the patients, there was another laparoscopic procedure besides the adrenal surgery: cholecystectomies (2), marsupialization of a renal cyst (2), block nephrectomy (2), partial nephrectomy for a tumor (1) and pancreatic cystectomy (1). One patient underwent a right laparoscopic adrenalectomy and an ipsilateral percutaneous nephrolithotomy.

CONCLUSION

The accumulated experience with 200 laparoscopic adrenal procedures has allowed the management of endocrine pathologies, such as, aldosteroma, pheochromocytoma, Cushing syndrome and rare entities, such as, cysts, myelolipomas in a suitable manner. Additionally, it has permitted us to extend the benefits of a minimally invasive procedure for large adrenal masses and selected oncology cases.

Which groups of patients are transfused? A study of red cell usage in London and southeast England

BACKGROUND AND OBJECTIVES

There are few published data on the use of red blood cells (RBC) by specialty in the United Kingdom. The aim of this survey was to identify major specialty users of blood to target for audit of transfusion practice with a view to minimizing inappropriate use and to support planning of blood supply needs for the future.

MATERIALS AND METHODS

Data were collected retrospectively of RBC units transfused at 62 hospitals/trusts in London and southeast England between April 1997 and March 1998.

RESULTS

A total of 594 810 transfused RBC units were successfully traced to their respective clinical specialties, representing 91.9% of all RBC units issued to the study hospitals. Of the RBC units transfused, 51.2% were transfused in surgical, 36.0% in medical and 12.8% in "combined" specialties.

CONCLUSIONS

This large study has accurately documented the clinical disciplines that are significant users of RBCs in our service area. It has heightened general understanding of RBC usage within hospitals. It has also raised questions on future strategies for reducing allogeneic blood transfusion that will be important if anticipated major reductions in blood supply occur in the near future.

A survey of physicians' attitudes to transfusion practice in critically ill patients in the UK

This study aimed to examine the attitudes of intensivists and haematologists to the use of blood and blood products using a scenario-based postal questionnaire. One hundred and sixty-two intensivists and 77 haematologists responded to the survey. In four scenarios, the baseline haemoglobin thresholds for red cell transfusion ranged from 6 to 12 g.dl(-1). There was significant variation between scenarios (p <0.005). Increasing age, high Acute Physiology and Chronic Health Status II score, surgery, acute respiratory distress syndrome, septic shock and lactic acidosis significantly (p <0.005) modified the transfusion threshold. There were greater variations in the baseline threshold for platelet transfusion. The majority of respondents (72.3%) selected a baseline haemoglobin threshold between 9 and 10 g.dl(-1). The thresholds for platelet transfusion were far less consistent.

Blood component use in critically ill patients

This prospective observational study was conducted to assess the current transfusion practice in critically ill patients. One thousand two hundred and forty-seven consecutive critically ill patients admitted between February 1999 and October 1999 were included in the study. Overall 666 (53%) patients were administered red cells. Transfused patients had significantly higher intensive care unit mortality but also had higher Acute Physiology and Chronic Health Evaluation II scores and longer durations of stay. The average pretransfusion haemoglobin concentration was < 9 g.dl(-1) in 75% of transfusion episodes. The common indications for transfusion were low haemoglobin (72%) and haemorrhage (25%). Overall, 202 (16%) and 281 (22%) of the patients were transfused platelets and fresh frozen plasma, respectively. The indications for transfusion were haemorrhage, low platelet counts, prolonged prothrombin time or to provide cover for invasive interventions. Most platelet transfusions were given at values in the order of 50-100 x 10(9).l(-1). The pretransfusion platelet count varied according to the indications for transfusion. This study showed that transfusion practice is consistent and that in general there does not seem to be an excessive use of blood components in critically ill patients.

Laparoscopic cholecystectomy

BACKGROUND

This study was undertaken to determine if patients undergoing laparoscopic cholecystectomy may be discharged home 4 h postoperatively with similar outcomes as patients admitted overnight.

METHODS

Patients were randomized to an outpatient group (OP), consisting of patients who were discharged after a 4-h stay in the Post Anesthesia Care Unit (PACU), or to an inpatient group. Variables compared between the two groups included patient demographics; degree of postoperative pain, nausea, vomiting, and patient satisfaction; amount of pain and nausea medication taken; and number of phone calls, readmissions, or complications. Statistical analysis was performed with students t-test, Fisher's exact test, and Wilcoxon's signed rank and rank sums tests as appropriate.

RESULTS

Eighty patients were initially enrolled. Two were converted and 4 required admission after being randomized to the OP group. Patients in the OP group received more oral pain medication prior to PACU discharge. Degree of pain, number of phone calls, readmission and complication rates, and patient satisfaction were similar between both groups. Of the 4 unexpected admissions, all were identified within the 4-h PACU stay.

CONCLUSIONS

Patients undergoing laparoscopic cholecystectomy who are discharged home 4 h postoperatively will experience the same satisfaction with no increase in complications as patients admitted overnight.

Effectiveness of a protocol to improve transfusion practice in knee replacement surgery

BACKGROUND AND OBJECTIVES

The available guidelines on red cell transfusion are not clearly defined and therefore have had only a modest impact on transfusion practice. The aims of this study were to assess the rate of compliance with a transfusion algorithm and its effect on transfusion practice.

MATERIALS AND METHODS

A prospective observational study was carried out on 101 patients who underwent primary elective total knee replacement surgery.

RESULTS

Only 30% of the patients were transfused. An overall compliance rate of 77% was achieved with the transfusion algorithm.

CONCLUSION

A transfusion algorithm, together with staff education, is effective in reducing both the number of patients transfused and inappropriate transfusions.

Treatment of Trypanosoma cruzi-infected children with nifurtimox: a 3 year follow-up by PCR

Patients suffering from Chagas' disease, as determined by positive serological results, were tested for further evidence of Trypanosoma cruzi infection by xenodiagnosis and PCR. The patients included 67 children aged from 0 to 10 years and 75 adults. All children were positive by PCR on their pre-therapy sample, while only 69% of the seropositive adults and none of the 78 seronegative control adults were PCR positive. Xenodiagnosis was positive in 79% of the children, but only in 21% of the adults. A group of 66 children was treated with nifurtimox, and followed up every 3 months during the first year and every 6 months during the second and third year post-therapy, by PCR, xenodiagnosis and serology. We concluded that PCR was the most effective test to monitor children for 3 years post-chemotherapy, when all the cases converted from positive to negative. Conventional serology, however, remained positive after that period in most cases. In contrast, conversion to negative xenodiagnosis occurred very early after treatment.

Retrospective study on red cell usage in primary total knee replacement surgery

BACKGROUND AND OBJECTIVES

There is wide variation in the use of red cell transfusions for the same clinical indication. The purpose of the study was to comment on preoperative and discharge haemoglobin (Hb) levels and perioperative blood loss, and to project the Hb level if transfusions were not administered.

MATERIALS AND METHODS

The case notes of 187 patients who underwent primary total knee replacement were reviewed retrospectively.

RESULTS

More than 90% of the transfusions were given in the immediate postoperative period as a matter of routine and a significant number of transfusions appeared to be unnecessary.

CONCLUSION

For surgical procedures involving moderate blood loss, transfusions should not be given as a routine and the decision to transfuse should take into consideration the clinical state of the patient, blood loss and pre- and postoperative Hb levels.

An international survey of unrelated umbilical cord blood banking

OBJECTIVES

To investigate operational and technical practices within the field of cord blood banking.

MATERIALS AND METHODS

Cord blood banks world-wide were invited to participate in a survey of collection, processing and testing. The survey covered a 12-month period up to August 1998.

RESULTS

Replies were received from 18 cord blood banks. Analysis of the survey responses demonstrated wide variations in many aspects of cord blood banking.

CONCLUSION

There is a need for standardization to ensure adoption of best practice.

Endotoxin-induced alterations of lipid and fatty acid compositions in rat liver peroxisomes

The structure/function of peroxisomal lipids in rat liver treated with a sublethal dose of endotoxin, a lipopolysaccharide (LPS), was investigated. Peroxisomes isolated from LPS-treated rat liver had remarkable alterations in lipid content compared with saline treated control liver peroxisomes. Cholesterol and phospholipids (PL) decreased significantly by 28.7% and 50.8%, respectively, leading to the change in the ratio of cholesterol/phospholipids (control 0.081 versus LPS 0.118, P < 0.001). A quantitative analysis from LPS-treated rat liver peroxisomes showed a general decrease in all classes of PL. No such alterations were observed in lipid content of other subcellular organelles. The peroxisomal fatty acid composition in LPS-treated animals was also altered. An analysis of fatty acid composition in PL and phosphatidylcholine from LPS-treated peroxisomes showed an increase in arachidonic acid (C20:4) and docosahexaenoic acid (C22:6). Very long chain (VLC) fatty acids (> C22:0) were also found increased in all classes of lipids in LPS-treated peroxisomes. Gadolinium chloride (GAD) mediated inactivation of Kupffer cells (KC) normalized cholesterol/PL ratio in LPS-treated peroxisomes. Collectively, the results indicate that the peroxisome metabolism of lipids and fatty acids is specifically altered in endotoxin-treated rat liver and at least part of the alterations may be mediated by factors released by KC.

Gas chromatographic determination of pesticides in vegetable samples by sequential positive and negative chemical ionization and tandem mass spectrometric fragmentation using an ion trap analyser

A selective and sensitive chromatographic method is described for the determination of nine organochlorine and organophosphorus pesticides in vegetable samples by gas chromatography-mass spectrometry. The proposed method combines the use of positive and negative chemical ionisation and tandem mass spectrometric fragmentation, resulting in a significant increase in selectivity and allowing the simultaneous confirmation and quantification of trace levels of pesticides in complex vegetable matrices. Parameters relative to ionisation and fragmentation processes were optimised to obtain maximum sensitivity. Repeatability and reproducibility studies yielded relative standard deviations lower than 25% in all cases. Identification criteria, such as retention time and relative abundance of characteristic product ions, were also evaluated in order to guarantee the correct identification of the target compounds. The method was applied to real vegetable samples to demonstrate its use in routine analysis.

Hospital control and multidrug-resistant pulmonary tuberculosis in female patients, Lima, Peru

We examined the prevalence of tuberculosis (TB), rate of multidrug-resistant (MDR) TB, and characteristics of TB on a female general medicine ward in Peru. Of 250 patients, 40 (16%) were positive by sputum culture and 27 (11%) by smear, and 8 (3%) had MDRTB. Thirteen (33%) of 40 culture-positive patients had not been suspected of having TB on admission. Six (46%) of 13 patients whose TB was unsuspected on admission had MDRTB, compared with 2 (7%) of 27 suspected cases (p = 0.009). Five (63%) of 8 MDRTB patients were smear positive and therefore highly infective. In developing countries, hospital control, a simple method of reducing the spread of MDRTB, is neglected.