Current anaesthesia and critical care最新文献

Transfusion triggers are increasingly accepted in surgery and in the critically ill. There is very little evidence to suggest a restrictive policy is harmful although higher levels might be sensible in those with cardiovascular disease. A considerable tranche of literature shows that blood is bad for a patient but to date no clear mechanism has emerged and there is an argument that needing blood, a surrogate for illness may be as relevant. The impact of anaemia in the postoperative phase has not been evaluated adequately. The triggers lend themselves to non-acute elective situations but where there is acute blood loss and haemodynamic instability a slightly higher threshold, nearer 10 g/dl, allows a margin of safety.

Platelets aggregate at the site of ruptured atherosclerotic plaques and have a key role in the pathophysiology of occlusive vascular events. Antiplatelet agents (APA) have proven efficacy in the primary and secondary prevention of ischaemic heart and cerebrovascular disease. The peri-operative management of patients taking such drugs is increasingly challenging and necessitates consideration of the risk of thrombosis following cessation of APA versus that of haemorrhage through continuation. We discuss the current and future role of platelet function tests in optimising clinical management of patients taking APA at the time of surgery.

Nasogastric gastric tubes (NGT) are placed blindly at the bedside in critical care although the procedure is associated with occasional serious pleuro-pulmonary complications. Various factors have been reported to predispose to the feeding tube malposition. We report a 60-year male in whom the attempted NGT insertion led to a near fatal complication. He was admitted to the medical intensive care-unit of our institute with dysphagia, cough with expectoration and breathlessness. In an un-cooperative patient with ineffective cough, the administration of sedation and multiple attempts to place the NGT resulted in an impacted tooth in the upper esophagus, and misplacement of the NGT. An urgent chest radiograph showed that the NGT had entered into the airway and its tip lay in the left main bronchus. A brief review of the complications associated with NGT insertion is presented.

Recipients of successful renal transplants experience a markedly improved quality of life and almost certainly improved survival compared to patients treated with dialysis. Haemodialysis treatment in the immediate period prior to transplantation is associated with a poorer outcome including a higher rate of delayed graft function (DGF). Individuals undergoing renal transplantation require close intra-operative monitoring with optimisation of intravascular fluid volume to maximise renal transplant perfusion. Whether mannitol, loop diuretics, dopamine or other therapies influence the rate of DGF is not possible to decide. For renal transplant recipients admitted immediately post-procedure to intensive care unit (ICU) the prognosis is good. This is in contrast to those admitted usually with overwhelming sepsis and concomitant acute kidney injury (AKI) late post-transplantation. An aggressive diagnostic strategy to ensure that co-infection is not missed is appropriate. The areas where consideration needs to be focused when managing renal transplant recipients on ICU include the fact that patients will have chronic kidney disease (CKD), the graft is more “sensitive” to the usual causes of AKI, central and peripheral venous access is often more problematic and immunosuppressive drug dosing often needs adjustment not only in the amount given but also the route of administration.

Renal replacement can be defined as “An extracorporeal system or attachment to supplement, support or replace some or all functions of the kidney”. The kidney is uniquely sensitive, because of its microvasculature and permeability, to injury, either as a result of direct damage by toxins, oxygen free radicals or filtered inflammatory mediators, or microvascular failure in states of shock and sepsis. The resulting renal injury and failure is a particular problem in the Intensive Care setting, leading to a greatly increased mortality.

This article explores the techniques available for renal replacement and support in the intensive care unit, discussing vascular access, choice of technique, choice of membrane, choice of dialysis buffer and strategies for maintaining circuit patency. It examines the techniques in common use in the United Kingdom and the outcome following renal replacement therapy, discussing some of the controversies surrounding renal replacement in terms of timing and dose. It also discusses some future development in technologies for renal replacement.