Tolerance: is it worth the risk?

BACKGROUND: The success of orthotopic liver transplantation (OLT) has been limited by the adverse effects of immunosuppression. The purpose of this study was to determine the safety and feasibility of withdrawing immunosuppression in OLT recipients to achieve tolerance. METHODS: Eighteen adult OLT recipients in our steroid-free protocol without rejection were selected for this protocol. All patients chosen for this trial were on tacrolimus monotherapy with normal liver function tests (LFTs). Tacrolimus was weaned as long as LFTs remained stable. Weaning was halted for elevations of liver enzymes and tacrolimus was increased to the last dosage at which the patients had normal LFTs. Rejection was treated by increasing tacrolimus to levels of 10-15 ng/ml. Mycophenolate mofetil (MMF) or sirolimus was added if there was severe rejection by biopsy. Steroids were used if there was no improvement. RESULTS: One patient has been weaned off immunosuppression. Three additional patients were weaned completely off but had tacrolimus resumed because of mild elevations in LFTs. Eleven of 18 (61%) patients had rejection. Two patients required steroid therapy and one required rabbit antithymocyte globulin in addition to MMF and steroids. One of the patients with rejection developed diabetes and one patient had renal failure, which subsequently resolved. One patient died following a stroke. CONCLUSIONS: Clinical tolerance can be achieved in a minority of patients, even when being maintained on minimum immunosuppression. The potential benefit of achieving tolerance must be weighed against the risks of rejection therapy in patients doing well on low-dose immunosuppression.     

Who is at increased risk of aspiration?

Editor—We read with interest Asai's editorial about therisks of pulmonary aspiration,¹ which was precipitated by ourreport of three cases of pulmonary aspiration occurring withthe laryngeal mask airway (LMA®).² Asai commented on thesix factors leading to aspiration (predisposing, patient, operation,anaesthesia, device and variability in the material aspirated)and concluded that we lack sufficient data to make evidence-baseddecisions and need to conduct further research to reduce theseuncertainties. While agreeing with Asai's conclusions, we feelthat his comments about device factors,     

Acute compartment syndrome. Who is at risk?

We have analysed associated factors in 164 patients with acute compartment syndrome whom we treated over an eight-year period. In 69% there was an associated fracture, about half of which were of the tibial shaft. Most patients were men, usually under 35 years of age. Acute compartment syndrome of the forearm, with associated fracture of the distal end of the radius, was again seen most commonly in young men. Injury to soft tissues, without fracture, was the second most common cause of the syndrome and one-tenth of the patients had a bleeding disorder or were taking anticoagulant drugs. We found that young patients, especially men, were at risk of acute compartment syndrome after injury. When treating such injured patients, the diagnosis should be made early, utilising measurements of tissue pressure.     

The clinical risk in heart transplantation: is it evaluable?

At the moment, there is no score to evaluate clinical risk in heart transplantation. There is a need for such an instrument due to the extended criteria for donations and for recipient evaluation for transplantation. We divided the 203 consecutive patients who underwent heart transplantation (HTx). Between January 1999 and December 2007 into two groups: high and low risk based on several common well-defined variables. Donors were also divided into high- and low-risk groups. We matched the four groups to obtain risk cohorts: GA (high risk), GB and GC (intermediate risk) versus GD (low risk). We analyzed the 30 day-mortality showing a significant difference between GD and the other groups (P = .05) in contrast to no significant difference in 1- and 3-year survival rates among GA, GB, GC, and GD. Although the development of a specific score for heart transplantation is desirable and would be useful, a careful, case-by-case evaluation is indispensable.     

Pacemaker placement and shoulder surgery: is there a risk?

INTRODUCTION

Surgery to the anterior aspect of the shoulder is performed by many surgical specialties but the techniques used by our cardiology colleagues for insertion of cardiac pacemaker wires are often not appreciated by the surgical community. The deltopectoral approach has been used for open pacemaker wire insertion for many years by cardiologists. METHODS We surveyed a group of subspecialty shoulder surgeons as well as orthopaedic trainees to see if this approach for pacemakers is well recognised. We tried to assess what level of knowledge exists regarding pacemaker placement in general as well as specific risks.

RESULTS

There appears to be a paucity of knowledge regarding pacemaker placement and related patient safety issues in both surveyed groups. There was no difference between the two groups, suggesting that the level of knowledge does not increase with experience and specialisation.

CONCLUSIONS

There is the potential to cause harm to patients if the insertion site and type of device is not identified before commencing surgery in this region and steps must be taken to minimise any intra-operative risk. There is a risk from direct injury to the pacemaker and/or leads as well as the hazards of using diathermy in close proximity to a pacemaker. There must be more widespread dissemination of this information in order to minimise risks to patients with pacemakers in situ.     

Starting dialysis is dangerous: how do we balance the risk?

Recent studies of timing of dialysis initiation have challenged the recent trend to earlier initiation of therapy. The observed outcomes though are a consequence of the balance between the risks of advanced uremia versus the inherent dangers relating to dialysis therapy itself. Many of these risks are inherent in how dialysis treatment is currently carried out, and may indeed be amenable to mitigation, through refinement of clinical practice (and potentially modality choice). This article aims to lay out a discussion relating to patient outcomes being the composite result of this balance, pivoting on the vulnerability of a particular patient to these attendant risks.     

Sodium is neither a risk nor a protective factor in urolithiasis?

Summary the effect of changes in urinary sodium, induced by dietary manipulation in normal subjects (NS) and in stone formers (SF) was studied by observing crytalluria qualitatively and by determining calcium, oxalate and phosphate crystallization quantitatively in an experimental model. In SF the calcium crystallization was significantly higher than in NS at all the three levels of urinary sodium studied. However, no difference was observed in oxalate and phosphate crystallization rates between these two groups. Calcium and oxalate (p< 0.05) and oxalate and phosphate (p< 0.001) were found to be correlated in NS but were non-significant in SF. The wide changes in the urinary sodium induced by dietary changes did not influence the crystallization rate of calcium, nor of oxalate and phosphate in NS as well as in SF. The results suggested that a sodium intake with lower and upper limits of 124 mg and 6,009 mg respectively did not act as inhibitor of crystallization rate nor did it induce hypercalciuria severe enough to pose a risk of stone formation. The results did not suggest that a high urinary sodium increases the solubility of calcium phosphate.     

Mercury in dental restoration: is there a risk of nephrotoxicity?

BACKGROUND: Concern has been voiced about exposure to mercury (Hg) from dental amalgam fillings, and there is a need to assess whether this leads to signs of nephrotoxicity. METHODS: A total of 101 healthy adults (80 males and 21 females) were included in this study. The population as grouped into those having amalgam fillings (39 males and 10 females) and those without (41 males and 11 females). Hg was determined in blood, urine, hair and nails to assess exposure. Urinary excretion of beta2-microglobulin (beta2M), N-acetyl-beta-D-glucosaminidase (NAG), gamma-glutamyltransferase (gammaGT) and alkaline phosphatase (ALP) were determined as markers of tubular damage. Albuminuria was assayed as an early indicator of glomerular dysfunction. Serum creatinine, beta2M and blood urea nitrogen (BUN) were determined to assess glomerular filtration. RESULTS: Hg levels in blood and urine were significantly higher in persons with dental amalgam than those without; in the dental amalgam group, blood and urine levels of Hg significantly correlated with the number of amalgams. Urinary excretion of NAG, gammaGT and albumin was significantly higher in persons with dental amalgam than those without. In the amalgam group, urinary excretion of NAG and albumin significantly correlated with the number of fillings. Albuminuria significantly correlated with blood and urine Hg. CONCLUSION: From the nephrotoxicity point of view, dental amalgam is an unsuitable filling material, as it may give rise to Hg toxicity. Hg levels in blood and urine are good markers of such toxicity. In these exposure conditions, renal damage is possible and may be assessed by urinary excretions of albumin, NAG, and gamma-GT.