Prediction of postoperative pain from assessment of pain induced by venous cannulation and propofol infusion.

BACKGROUND: Postoperative pain may lead to delayed mobilization, persisting pain, and psychosocial distress. There are no simple and reliable techniques for prediction of postoperative pain. This study was designed to evaluate if pain induced by venous cannulation or propofol injection can be used to predict postoperative pain. METHODS: This prospective study included 180 patients scheduled for laparoscopic cholecystectomy. Pain intensity associated with peripheral venous cannulation and administration of propofol preoperatively and pain intensity, and use of opioid postoperatively was recorded. RESULTS: Patients scoring cannulation-induced pain intensity > 2.0 VAS units were given postoperative opioid more often (65% vs. 36%; P < 0.001), earlier (12 min vs. 90 min; P < 0.001), and in higher doses (4.8 mg vs. 0 mg; P < 0.001), and also reported higher levels of postoperative pain intensity (5.8 vs. 2.9 VAS units; P < 0.001). There were also significant (P < 0.01) correlations with postoperative pain intensity (rs = 0.24), time to opioid administration (rs = -0.26), and total dose of opioid (rs = 0.25). Propofol-induced pain intensity correlated significantly (P < 0.05) with postoperative pain intensity (rs = 0.19). CONCLUSION: Pain intensity associated with venous cannulation and propofol infusion can easily be evaluated at bedside before surgery without specific equipment or training. Patients scoring > 2.0 VAS units on venous cannulation were found to have 3.4 times higher risk of postoperative pain after laparoscopic cholecystectomy. Low pain intensity associated with venous cannulation and propofol infusion indicate lower risk of postoperative pain.

Outcome and complications after intra-arterial thrombolysis for lower limb ischaemia with or without continuous heparin infusion.

BACKGROUND: Thrombolysis is a common treatment for acute leg ischaemia. The purpose of this study was to evaluate different thrombolytic treatment strategies, and risk factors for complications. METHODS: This was a retrospective analysis of prospective databases from two vascular centres. One centre used a higher dose of heparin and recombinant tissue plasminogen activator (rtPA). RESULTS: Some 749 procedures in 644 patients of median age 73 years were studied; 353 (47·1 per cent) of the procedures were done in women. The aetiology of ischaemia was graft occlusion in 38·8 per cent, acute arterial thrombosis in 32·2 per cent, embolus in 22·3 per cent and popliteal aneurysm in 6·7 per cent. Concomitant heparin infusion was used in 63·2 per cent. The mean dose of rtPA administered was 21·0 mg, with a mean duration of 25·2 h. Technical success was achieved in 80·2 per cent. Major amputation and death within 30 days occurred in 13·1 and 4·4 per cent respectively. Bleeding complications occurred in 227 treatments (30·3 per cent). Blood transfusion was needed in 104 (13·9 per cent). Three patients (0·4 per cent of procedures) had intracranial bleeding; all were fatal. Amputation-free survival was 83·6 per cent at 30 days at both centres. In multivariable analysis, preoperative severe ischaemia with motor deficit was the only independent risk factor for major bleeding (odds ratio (OR) 2·98; P <0·001). Independent risk factors for fasciotomy were severe ischaemia (OR 2·94) and centre (OR 6·50). Embolic occlusion was protective for major amputation at less than 30 days (OR 0·30; P = 0·003). Independent risk factors for death within 30 days were cerebrovascular disease (OR 3·82) and renal insufficiency (OR 3·86). CONCLUSION: Both treatment strategies were successful in achieving revascularization with acceptable complication rates. Continuous heparin infusion during intra-arterial thrombolysis appeared to offer no advantage.

Clinical guidelines on central venous catheterisation. Swedish Society of Anaesthesiology and Intensive Care Medicine.

Safe and reliable venous access is mandatory in modern health care, but central venous catheters (CVCs) are associated with significant morbidity and mortality, This paper describes current Swedish guidelines for clinical management of CVCs The guidelines supply updated recommendations that may be useful in other countries as well. Literature retrieval in the Cochrane and Pubmed databases, of papers written in English or Swedish and pertaining to CVC management, was done by members of a task force of the Swedish Society of Anaesthesiology and Intensive Care Medicine. Consensus meetings were held throughout the review process to allow all parts of the guidelines to be embraced by all contributors. All of the content was carefully scored according to criteria by the Oxford Centre for Evidence-Based Medicine. We aimed at producing useful and reliable guidelines on bleeding diathesis, vascular approach, ultrasonic guidance, catheter tip positioning, prevention and management of associated trauma and infection, and specific training and follow-up. A structured patient history focused on bleeding should be taken prior to insertion of a CVCs. The right internal jugular vein should primarily be chosen for insertion of a wide-bore CVC. Catheter tip positioning in the right atrium or lower third of the superior caval vein should be verified for long-term use. Ultrasonic guidance should be used for catheterisation by the internal jugular or femoral veins and may also be used for insertion via the subclavian veins or the veins of the upper limb. The operator inserting a CVC should wear cap, mask, and sterile gown and gloves. For long-term intravenous access, tunnelled CVC or subcutaneous venous ports are preferred. Intravenous position of the catheter tip should be verified by clinical or radiological methods after insertion and before each use. Simulator-assisted training of CVC insertion should precede bedside training in patients. Units inserting and managing CVC should have quality assertion programmes for implementation and follow-up of routines, teaching, training and clinical outcome. Clinical guidelines on a wide range of relevant topics have been introduced, based on extensive literature retrieval, to facilitate effective and safe management of CVCs.

Survey of central venous catheterisation practice in Sweden.

BACKGROUND: Clinical guidelines on central venous catheterisation were introduced by the Swedish Society of Anaesthesiology and Intensive Care Medicine in 2011. The purpose of this study was to investigate current national practice and assess to what extent these guidelines influence clinical routines in Swedish operating wards and intensive care units. METHODS: An invitation to participate in an online survey regarding central venous catheterisation was sent to 65 departments of anaesthesiology and intensive care medicine in Sweden. The survey aimed at investigating routine standards (part 1) and 24-h clinical practice (part 2). RESULTS: Forty-seven (72%) and 49 (75%) of 65 departments took part in parts 1 and 2, respectively, and 73% adhered to the national guidelines. Many units monitored mechanical (42%) and infectious (69%) complications. Ultrasound was used by more than 50%. Checklists for insertion were used by 22%. Physicians inserted most catheters. No serious complications were reported during the 24-h study period. Ninety-seven non-tunnelled, 17 venous ports, 9 tunnelled and 8 peripheral central venous catheters were inserted. Ninety-three (71%) catheters were inserted in operating rooms, and 31 (24%) in intensive care units. Catheterisations were followed up by chest X-ray in most departments. CONCLUSION: Knowledge of the Swedish guidelines was adequate, and most participating departments had local catheterisation routines. We could identify some variation in practice, but overall adherence to the guidelines was good. Nevertheless, monitoring of procedures and complications of cannulation and maintenance could be in need of improvement.

Morning conferences for anaesthesiologists - to be or not to be?

BACKGROUND: The main objectives of this study were to clarify the contents of and attitudes to morning conferences for physicians at Swedish departments of anaesthesiology and intensive care medicine. METHODS: A prospective cross-sectional three-part study was carried out. Heads of departments responded to a national survey on the structure and content of morning conferences. A questionnaire on attitudes to and general contents of morning conferences was filled out by anaesthesiologists in the Scania region in southern Sweden. Furthermore, telephone interviews were made with anaesthesiologists on primary night call in the Scania region to obtain information on whether their needs to report had been met and on how the conferences had actually been carried out and attended by the physicians. RESULTS: Information was obtained from 52 departmental heads (80%), 113 anaesthesiologists (53%), and 83 physicians on primary call (92%). Issues most frequently brought up were reports from physicians on night call, discussions of clinical matters, issues of staffing, and organizational matters. Daily morning conferences were strongly favoured for intercollegial solidarity and contacts, and were mainly and regularly used for reports from physicians on night call. At 95% of them, physicians on night call considered themselves to have been allowed to report what they wanted or needed to. CONCLUSIONS: Daily morning conferences enable regular exchange of information and professional experience, and are considered by Swedish anaesthesiologists to be most valuable for intercollegial solidarity and contacts. Before changes are being made in frequency or duration of morning conferences, their actual structure and content should be carefully evaluated and critically challenged to fit specific needs of that individual department.

Fluid balance monitoring by cuff-occluded rate of rise of peripheral venous pressure in haemodialysis patients.

Cuff-occluded rate of rise of peripheral venous pressure has been proposed to reflect volume changes in experimental studies. The aim of this study was to evaluate changes in cuff-occluded rate of rise of peripheral venous pressure associated with fluid removal by haemodialysis in six adult patients with chronic renal failure on intermittent haemodialysis. Measurements were carried out before and after each haemodialysis session. The volume of fluid removed (indexed to body surface area) linearly correlated with changes in cuff-occluded rate of rise of peripheral venous pressure (r = 0.84; r(2) = 0.70; p = 0.037). Cuff-occluded rate of rise of peripheral venous pressure may be feasible for future clinical monitoring of individual fluid balance.

Complications associated with peripheral or central routes for central venous cannulation.

We undertook a review of studies comparing complications of centrally or peripherally inserted central venous catheters. Twelve studies were included. Catheter tip malpositioning (9.3% vs 3.4%, p = 0.0007), thrombophlebitis (78 vs 7.5 per 10,000 indwelling days, p = 0.0001) and catheter dysfunction (78 vs 14 per 10,000 indwelling days, p = 0.04) were more common with peripherally inserted catheters than with central catheter placement, respectively. There was no difference in infection rates. We found that the risks of tip malpositioning, thrombophlebitis and catheter dysfunction favour clinical use of centrally placed catheters instead of peripherally inserted central catheters, and that the two catheter types do not differ with respect to catheter-related infection rates.

Risk factors for haemorrhage during local intra-arterial thrombolysis for lower limb ischaemia.

Assessment of clinical risk factors for haemorrhagic complications in patients undergoing intra-arterial thrombolysis for lower limb ischaemia. Retrospective reviews of consecutive patients subjected to intra-arterial thrombolysis due to lower limb ischemia at the Vascular Center, Malmö University Hospital, during a 5-year period from 2001 to 2005. Two hundred and twenty intra-arterial thrombolytic procedures were carried out in 195 patients (46% women), median age 73 years. Haemorrhagic complications were recorded in 72 procedures (33%), of which 13 were discontinued. Haemorrhage at the introducer and distant sites occurred in 53 and 32 procedures, respectively. Thrombolysis for occluded synthetic grafts was associated with higher risk of haemorrhage (P = 0.043). The platelet count was lower (P = 0.017) and the dose of alteplas higher (P = 0.041) in bleeders than in non-bleeders. Age was not associated with haemorrhage (P = 0.30). Two patients died during thrombolysis, one of them due to intracerebral haemorrhage. The grade of thrombolysis was an independent predictor of both in-hospital amputation (P < 0.001; OR 3.5 [95% CI 2.1-5.8]) and mortality (P = 0.021; OR 3.0 [95% CI 1.2-7.9]). The in-hospital amputation-free survival rate was 85% (188/220). Haemorrhage associated with thrombolysis is common, but does seldom require discontinuation of treatment. Insertion of introducers for local thrombolysis through synthetic grafts, lower platelet count and higher alteplas dose were found to be risk factors for haemorrhage. An algorithm for clinical management of haemorrhage has been proposed.

Management of inadvertent arterial catheterisation associated with central venous access procedures.

OBJECTIVE: This study aims to describe the clinical management of inadvertent arterial catheterisation after attempted central venous catheterisation. METHODS: Patients referred for surgical or endovascular management for inadvertent arterial catheterisation during a 5-year period were identified from an endovascular database, providing prospective information on techniques and outcome. The corresponding patient records and radiographic reports were analysed retrospectively. RESULTS: Eleven inadvertent arterial (four common carotid, six subclavian and one femoral) catheterisations had been carried out in 10 patients. Risk factors were obesity (n=2), short neck (n=1) and emergency procedure (n=4). All central venous access procedures but one had been made using external landmark techniques. The techniques used were stent-graft placement (n=6), percutaneous suture device (n=2), external compression after angiography (n=1), balloon occlusion and open repair (n=1) and open repair after failure of percutaneous suture device (n=1). There were no procedure-related complications within a median follow-up period of 16 months. CONCLUSIONS: Inadvertent arterial catheterisation during central venous cannulation is associated with obesity, emergency puncture and lack of ultrasonic guidance and should be suspected on retrograde/pulsatile catheter flow or local haematoma. If arterial catheterisation is recognised, the catheter should be left in place and the patient be referred for percutaneous/endovascular or surgical management.

Routine chest X-ray is not required after a low-risk central venous cannulation.

BACKGROUND: Knowledge of the radiographic catheter tip position after central venous cannulation is normally not required for short-term catheter use. Detection of a possible iatrogenic pneumothorax may nevertheless justify routine post-procedure chest X-ray. Our aim was to design a clinical decision rule to select patients for radiographic evaluation after central venous cannulation. METHODS: A total of 2230 catheterizations performed using external jugular, internal jugular or subclavian venous approaches during a 4-year period were included consecutively. Information on patient data and corresponding procedures was recorded prospectively. A post-procedure chest X-ray was obtained after each cannulation. RESULTS: Thirteen cases (0.58%) of cannulation-associated pneumothorax were identified. The risk of pneumothorax after a technically difficult (1.8%) or subclavian (1.6%) cannulation was significantly higher than after cannulation not considered as difficult (0.37%) or performed using other routes (0.33%). Clinical signs of pneumothorax within 8 h of cannulation were found in all seven patients with pneumothorax requiring specific treatment. A new clinical decision rule for radiographic evaluation after central venous cannulation based on the results of the present study shows that 48% of the post-procedure chest X-rays performed in our patients were clinically redundant. CONCLUSION: Clinical symptoms were reported in all patients with pneumothorax requiring specific treatment. Approximately half of the post-procedure chest X-ray controls could be avoided using the proposed clinical decision rule to select patients for radiographic evaluation after central venous cannulation. A large prospective multi-centre study should be carried out to further evaluate this decision rule.

Racemic, S(+)- and R(-)-ketamine do not increase elevated intracranial pressure.

BACKGROUND: There is controversy regarding the influence of ketamine and its enantiomers on cerebral haemodynamics at increased intracranial pressure (ICP). This study was designed to compare cerebrovascular responses, with particular respect to ICP, to bolus injections of racemic, S(+)- and R(-)-ketamine in an experimental model of intracranial hypertension. METHODS: Nine pigs were anaesthetised with fentanyl and vecuronium during mechanical normoventilation. The ICP was raised with extradural balloon catheters to 23 mmHg. The intra-arterial xenon clearance technique was used to determine cerebral blood flow (CBF). Three 60-s bolus injections of racemic ketamine (10 mg/kg), S-ketamine (5 mg/kg) and R-ketamine (20 mg/kg) were given in a randomised sequence. Cerebral and systemic haemodynamic responses were evaluated before and at 1, 5, 10, 15, 30 and 45 min after each injection. RESULTS: Racemic ketamine decreased ICP (P=0.026) by maximally 10.8%, whereas there was no effect on ICP of S- (P=0.178) or R-ketamine (P=0.15). All study drugs had similar biphasic effects on CBF, with maximal initial decreases by 25-29%, followed by transient increases by 7-15%, and a reduction of mean arterial pressure by maximally 22-37%. CONCLUSIONS: A decrease or a lack of an increase in ICP in response to intravenous bolus injections of racemic, S- or R-ketamine suggests that the administration of racemic or S-ketamine might be safe in patients with intracranial hypertension due to a space-occupying lesion. The ICP-lowering effect indicates that racemic ketamine might offer a therapeutic advantage over S-ketamine.

Application of software design principles and debugging methods to an analgesia prescription reduces risk of severe injury from medical use of opioids.

A prescription is a health-care program implemented by a physician or other qualified practitioner in the form of instructions that govern the plan of care for an individual patient. Although the algorithmic nature of prescriptions is axiomatic, this insight has not been applied systematically to medication safety. We used software design principles and debugging methods to create a "Patient-oriented Prescription for Analgesia" (POPA), assessed the rate and extent of adoption of POPA by physicians, and conducted a statistical process control clinical trial and a subsidiary cohort analysis to evaluate whether POPA would reduce the rate of severe and fatal opioid-associated adverse drug events (ADEs). We conducted the study in a population of 153,260 hospitalized adults, 50,576 (33%) of whom received parenteral opioids. Hospitalwide, the use of POPA increased to 62% of opioid prescriptions (diffusion half-life = 98 days), while opioid-associated severe/fatal ADEs fell from an initial peak of seven per month to zero per month during the final 6 months (P < 0.0016) of the study. In the nested orthopedics subcohort, the use of POPA increased the practice of recording pain scores (94% vs. 72%, P < 0.00001) and the use of adjuvant analgesics (95% vs. 40%, P < 0.00001) and resulted in fewer opioid-associated severe ADEs than routine patient-controlled analgesia (PCA) (0% vs. 2.7%, number needed to treat (NNT) = 35, P < 0.015). The widespread diffusion of POPA was associated with a substantial hospitalwide decline in opioid-associated severe/fatal ADEs.

The incidence and risk of central venous catheter malpositioning: a prospective cohort study in 1619 patients.

Central venous catheters are used in various hospital wards. An anterior-posterior chest X-ray is usually obtained soon after cannulation to assess the location of the catheter tip. This prospective clinical study was designed to determine the radiographic catheter tip position after central venous cannulation by various routes, to identify clinical problems possibly associated with the use of malpositioned catheters and to make a cost-benefit analysis of routine chest X-ray with respect to catheter malposition. A total 1619 central venous cannulations were recorded during a three-year period with respect to patient data, information about the cannulation procedures, the radiographic catheter positions and complications during clinical use. The total incidence of radiographic catheter tip malposition, defined as extrathoracic or ventricular positioning, was 3.3% (confidence interval 25 to 4.3%). Cannulation by the right subclavian vein was associated with the highest risk of malposition, 9.1%, compared with 1.4% by the right internal jugular vein. Six of the 53 malpositioned catheters were removed or adjusted. No case of malposition was associated with vascular perforation, local venous thrombosis or cerebral symptoms. We conclude that the radiographic incidence of central venous catheter malpositioning is low and that clinical use of malpositioned catheters is associated with few complications. However, determination of the catheter position by chest X-ray should be considered when mechanical complications cannot be excluded, aspiration of venous blood is not possible, or the catheter is intended for central venous pressure monitoring, high flow use or infusion of local irritant drugs.

Sustained intravascular exposure to propofol does not prolong pain at the site of injection.

BACKGROUND: Pain at the site of intravenous injection of propofol is a common clinical finding. This double-blind, randomized cross-over study was designed to evaluate whether venous occlusion applied during injection of a low dose of propofol reduces the intensity of pain at the site of injection compared with no occlusion. METHODS: Bilateral 0.5-ml injections of an emulsion containing 10 mg/ml of propofol were given over 30 s in 75 adult surgical patients. Each patient was given one injection with and one without 60-s occlusion of the cannulated vein with a 10-min interval, and asked to score the maximal pain intensity on a visual analogue scale (VAS). RESULTS: The maximal pain intensity [median (25th percentile; 75th percentile), range] at the site of injection was 0.5 (0; 3.5), 0-8.0 VAS units with venous occlusion and 0.5 (0; 1.4), 0-6.0 VAS units without occlusion (P= 0.042). Pain was first reported within 20 s regardless of the study regimen and was not prolonged by local venous occlusion. CONCLUSION: Venous occlusion augments pain intensity at the site of propofol injection without prolonging pain, implying that propofol-induced pain is determined more by the blood concentration than by the duration of intravascular exposure. The low intensity of pain induced by low-dose propofol and the fading of pain despite sustained exposure suggest that initial low-dose administration of propofol should be evaluated for the attenuation of local pain induced by higher intravenous doses of propofol.

Low-dose propofol reduces the incidence of moderate to severe local pain induced by the main dose.

BACKGROUND: Local pain on injection of propofol remains a considerable problem in clinical anaesthesiology. As slow infusion of a low dose of propofol induces little or no pain at the site of injection, and as propofol-induced pain fades during prolonged exposure, this randomized, double-blind, clinical cross-over study was designed to test whether pain on injection of propofol is attenuated by initial slow injection of a low dose of propofol by the same intravenous line. METHODS: Seventy-seven adult surgical patients were cannulated in a dorsal vein on each hand. In each cannula, a 0.5-ml priming dose of either propofol 10 mg/ml dissolved in an emulsion of medium- and long-chain triglycerides or aqueous sodium chloride 9.0 mg/ml was injected over 30 s, and followed 120 s later by a main dose of 2.0 ml of the same propofol formula over 6 s. After each injection, the patients were asked by a blind investigator to score the maximal pain intensity on a visual analogue scale (VAS). RESULTS: Although the decrease in maximal pain intensity did not reach statistical significance (P= 0.070), significantly fewer patients reported moderate or severe pain intensity (corresponding to 3.0 VAS units or more) after the main dose of propofol was preceded by a priming dose of propofol than by sodium chloride (P= 0.041). CONCLUSIONS: The incidence of moderate to severe local pain induced by intravenous propofol can be decreased by a readily applicable technique in which a low dose of propofol emulsion is slowly administered by the same intravenous route 2 min in advance.

Cerebral physiological responses to bolus injection of racemic, S(+)- or R(-)-ketamine in the pig.

BACKGROUND: Little is known about the influence of ketamine and its enantiomers on cerebral haemodynamics, and there are no direct comparison reports. This study was designed to evaluate cerebrovascular responses to bolus injections of racemic, S(+)- and R(-)-ketamine in an established experimental model. METHODS: Anaesthesia was induced with propofol in 14 pigs and maintained with fentanyl and vecuronium. The intra-arterial xenon clearance technique was used to calculate the cerebral blood flow (CBF). Eight pigs (part I) were given three consecutive 60-s intravenous (i.v.) bolus injections of 10 mg/kg of racemic ketamine (Ketalar, Pfizer), and cerebral and systemic physiological responses were studied for 30 min after each injection. Following the determination of equipotent doses of the racemate and its enantiomers by recumbency tests, bolus injections of racemic ketamine (10 mg/kg), S-ketamine (5 mg/kg) and R-ketamine (20 mg/kg) were given in randomized sequence to another six pigs (part II) and evaluated at 1, 5, 10, 15, 25 and 40 min. RESULTS: No statistically significant acute tolerance in the CBF response to racemic ketamine was found in part I of the study. In part II, the decreases in the mean arterial pressure (MAP) and CBF by S-ketamine were significantly smaller than those by racemic and R-ketamine (both P < 0.001). No study drug had any significant effect on the cerebral arteriovenous oxygen content difference (C(av)O(2)) over time, but S-ketamine was associated with lower C(av)O(2) than racemic ketamine (P = 0.008) and R-ketamine (P = 0.016). CONCLUSIONS: Bolus injection of S-ketamine was associated with less cerebral and systemic haemodynamic depression than racemic or R-ketamine in equipotent doses in this experimental model. These findings indicate possible advantages of S-ketamine over racemic ketamine.

Desflurane induces more cerebral vasodilation than isoflurane at the same A-line autoregressive index level.

BACKGROUND: Clinical use of desflurane in neuroanesthesia remains under debate. Comparison of dose-dependent vasodilatory properties between desflurane and isoflurane, the more traditional volatile agent for clinical neuroanesthesia, requires equianesthetic dosing of the agents. Reproducible neurophysiological measurements of the level of anesthesia in an individual, e.g. the A-line autoregressive index (AAI), can be used for an equipotent dosage of two volatile agents in the same individual. METHODS: Desflurane and isoflurane, in randomized order, were titrated to a stable AAI level of 15-20 in 18 ASA I or II patients. The mean flow velocity (Vmca) and pulsatility index (PI) in the middle cerebral artery were then measured with transcranial Doppler at an end-tidal CO(2) concentration of 4.4%. RESULTS: For desflurane Vmca was 11% higher [95% confidence interval (CI), 5-18%; P = 0.0020] and PI was 13% lower (95% CI, 3-23%; P = 0.0083) than for isoflurane. The mean arterial blood pressure did not differ between the agents. The fraction of MAC necessary for the intended AAI level was 35% lower (95% CI, 20-49%; P = 0.00016) with desflurane than with isoflurane. CONCLUSION: Desflurane was associated with more cerebral vasodilation than isoflurane at the same depth of anesthesia, as indicated by the AAI. This attributes further reason for caution in the use of desflurane in clinical neuroanesthesia. The difference between desflurane and isoflurane in the MAC fractions required for the same AAI level confirms the limitations of MAC in defining the level of anesthesia.

Intensive care treatment of severe mixed metabolic acidosis.

We report a case of severe metabolic acidosis associated with acute renal failure and septicaemia following treatment with maximal therapeutic doses of metformin and diclofenac. On the second day of intensive care the patient deteriorated with respiratory insufficiency and abdominal pain during continuous renal replacement therapy. A laparoscopy revealed a perforated cholecystitis with abscess formation. The patient regained renal function and recovered. Intake of diclofenac 5 days before this episode could have been the main cause of renal insufficiency and metabolic acidosis in this patient and could also have delayed surgical treatment by masking early clinical signs of perforated cholecystitis. The renal failure may also have caused metformin and lactate to accumulate, contributing to the mixed pattern of metabolic acidosis. This case report describes a mixed organic and non-organic metabolic acidosis associated with acute renal failure, presumably resulting from a combination of drugs and diseases often found in the elderly - metformin for diabetes mellitus and a non-steroidal anti-inflammatory drug for cholecystolithiasis. Acid-base balance and electrolyte changes were rapidly normalized by continuous renal replacement therapy.

Less local pain on intravenous infusion of a new propofol emulsion.

BACKGROUND: Local pain at the site of intravenous (iv) injection of propofol remains a considerable problem in clinical anaesthesiology, and particularly so in infants. The aim of the present study was to compare the influence of two different emulsions of propofol on local pain following iv administration. METHODS: Eighty adult patients (ASA I-II) scheduled for ear-nose-throat or plastic surgery were randomly allocated into two study groups: A and B. A 1.0-mm teflon cannula (BD, Helsingborg, Sweden) was inserted into a dorsal vein on each hand. Each patient was given two 3.0-ml iv bolus injections of two different propofol emulsions of 10 mg ml(-1) over 2 s, one in each cannula, at 5-min intervals. The first study drug administered was Diprivan (AstraZeneca, Södertälie, Sweden) in group A (n = 34) and Propofol-Lipuro (Braun, Melsungen, Germany) in group B (n = 39). Each patient was then asked by a blinded investigator to score maximal pain intensity on a visual analogue scale (VAS). RESULTS: The maximal intensity of propofol-induced local pain was significantly (P < 0.0001) lower after Propofol-Lipuro than after Diprivan--median 1 (25th percentile: 0; 75th percentile: 2) range 0-6 vs. 3 (0; 5) 0-9 VAS units. CONCLUSION: The considerably lower intensity of local pain found to be associated with iv administration of the new drug formula Propofol-Lipuro indicates that emulsions of propofol based on medium- and long-chain triglycerides have a clinical advantage over traditional ones for induction of anaesthesia.