Peri-operative management of the obese surgical patient 2015: Association of Anaesthetists of Great Britain and Ireland Society for Obesity and Bariatric Anaesthesia.

Guidelines are presented for the organisational and clinical peri-operative management of anaesthesia and surgery for patients who are obese, along with a summary of the problems that obesity may cause peri-operatively. The advice presented is based on previously published advice, clinical studies and expert opinion.

Changes in serum albumin concentration and volume expanding effects following a bolus of albumin 20% in septic patients.

BACKGROUND: Patients with systemic sepsis develop a capillary leak syndrome, and serum -albumin concentration decreases. Hyperoncotic albumin infusion can be used for volume expansion in these patients, but the degree and duration of effect are not well described. We assessed volume expansion by albumin 20% infusion and compared the retention of infused albumin in septic patients and healthy controls. METHODS: We gave albumin 20%, 200 ml as a rapid infusion to 70 patients with septic shock and 26 controls. Blood samples were taken before and 1, 5, 15, 30, 60, 120 and 240 min after the infusion for measurement of serum albumin concentration and haematocrit. Haemodilution and the percentage of administered albumin remaining intravascularly at each time were calculated. RESULTS: The mean proportion of the increase in albumin remaining at 4 h was 68.5 (sd 10)% in septic patients and 79 (5)% in controls (P<0.001). The albumin 20%, 200 ml caused a secondary fluid resorption and volume expansion maximal at 30 min, equivalent to a 430 ml infusion in septic patients and 500 ml in controls. CONCLUSIONS: After giving albumin, serum albumin concentrations decrease significantly faster in septic patients than in healthy controls.

Serum albumin: touchstone or totem?

A decrease in serum albumin concentrations is an almost inevitable finding in disease states, and is primarily mediated in the acute phase by alterations in vascular permeability and redistribution. This change is not disease specific but marked changes that persist are generally associated with a poorer prognosis. Critical appraisal of long-standing practices and the availability of alternative colloid solutions have led to a reduction in albumin replacement therapy, and a widespread tolerance of lower albumin concentrations in patients. The factors determining serum albumin concentrations, their measurement and the implications of hypoalbuminaemia are reviewed. The clinical value of serum albumin measurement is discussed.

Administration of albumin to patients with sepsis syndrome: a possible beneficial role in plasma thiol repletion.

1. Albumin is often administered intravenously to critically ill patients as a volume expander, to combat hypoalbuminaemia, and to decrease hyperbilirubinaemia. There is, however, an ongoing debate concerning the therapeutic benefit of the former which is an expensive form of treatment.2. Albumin has several biological functions, in particular as a ligand binder. It also acts as an extracellular transition metal ion-binding and radical-scavenging antioxidant. These functions are influenced by the presence of an exposed thiol group (cys 34) on the surface of the albumin molecule. 3. The ability of infused albumin to influence the plasma thiol pool, and hence antioxidant potential, was investigated in patients with sepsis syndrome.4. Plasma thiol levels rose rapidly after albumin infusion and remained elevated even after plasma albumin levels had declined significantly, due to interstitial leakage. Data are suggestive of some form of thiol exchange in the plasma of these patients between albumin and molecules containing oxidized thiol groups.5. Administration of albumin to patients with sepsis syndrome leads to a sustained increase in plasma thiols. Thiols have several important antioxidant functions, and thiol repletion in these patients, who are known to suffer from oxidative stress, may have beneficial antioxidant effects. Antioxidant repletion may represent an important facet of clinically administered albumin.

Tracheal intubation conditions after one minute: rocuronium and vecuronium, alone and in combination.

Rocuronium is a recently introduced nondepolarising neuromuscular blocking agent with a rapid onset and intermediate duration of action. Experimental observations have suggested that during onset it acts synergistically with other nondepolarising agents, but that at a steady state the combined action is additive. In order to investigate whether synergism during onset produces a clinical benefit we performed the following study of tracheal intubation conditions. Consenting patients presenting for elective surgery which required tracheal intubation were randomly allocated to receive a standard anaesthetic and either a twice ED95 dose of rocuronium, or vecuronium, or an equipotent mixture of both drugs. Tracheal intubation conditions were assessed after 60 s and scored as excellent, good, poor or impossible. The conditions produced in the rocuronium and the mixture groups were similar and both were significantly better than those of vecuronium. Excellent intubation conditions were achieved in 57% of the rocuronium group, 70% of the mixture group and 27% of the vecuronium group. We conclude that a mixture of rocuronium and vecuronium acts synergistically during the early part of their action and a mixture containing one ED95 of both agents provides comparable conditions for tracheal intubation as an equipotent dose of rocuronium.

Delayed amniotic fluid embolism following caesarean section under spinal anaesthesia.

A case of amniotic fluid embolus is described with an acute onset occurring 90 min after surgical delivery in a mildly pre-eclamptic primigravida undergoing Caesarean section for a breech presentation. Severe disseminated intravascular coagulation and massive postpartum haemorrhage were corrected and she went on to make a full recovery. The pathophysiology of amniotic fluid embolism is discussed and new diagnostic tests are reviewed. It is suggested that in this patient an amniotic fluid collection in dilated uterine veins was mobilised as venous tone returned following the offset of spinal anaesthesia and sympathetic blockade.