Dopexamine reverses colonic but not gastric mucosal perfusion defects in lethal endotoxin shock

Background. Whilst dopexamine appears to increase overall splanchnicblood flow in postoperative and septic patients, the effectson gastric mucosal perfusion are controversial and based onconcomitantly increasing mucosal to arterial PCO₂ gradients(PdCO₂). We hypothesized that dopexamine alters splanchnic bloodflow distribution and metabolism during experimental endotoxinshock and modifies the inflammatory response induced by endotoxin. Methods. In an experiment with anaesthetized normovolaemic,normoventilated pigs, 21 animals were randomized into: (i) subacutelethal endotoxin shock for 14 h (n=7 at baseline); (ii)endotoxin shock with dopexamine infusion (aiming to exceed baselinecardiac output, n=7); or (iii) controls (n=7). Regional bloodflow and metabolism were monitored. Results. Endotoxin produced a hypodynamic phase followed bya normo/hyperdynamic, hypotensive phase. Despite increasingsystemic blood flow in response to dopexamine, proportionalsplanchnic blood flow decreased during the hypodynamic phase.Dopexamine gradually decreased fractional coeliac trunk flow,while fractional superior mesenteric arterial flow increased.Dopexamine induced early arterial hyperlactataemia and augmentedthe gastric PdCO₂ gradient while colonic luminal lactate releaseand colonic PdCO₂ gradient were reversed. Dopexamine did notmodify the inflammatory response as evaluated by arterial IL-1ßand IL-6 concentrations. Conclusions. Dopexamine protects colonic, but not gastric mucosalepithelium in experimental endotoxin shock. This may be relatedto redistribution of blood flow within the splanchnic circulation. Br J Anaesth 2003; 91: 878–85     

Genotype and interleukin-10 responses after cardiopulmonary bypass

Background. The pro- and anti-inflammatory cytokine balancehas been implicated in outcome from inflammatory conditions,and cardiopulmonary bypass is associated with a marked inflammatoryresponse. Interleukin-10 (IL-10) is an anti-inflammatory cytokineand levels have been shown to be highest in those patients whodevelop sepsis after trauma or surgery. IL-10 levels vary betweenindividuals and genotype may dictate the IL-10 response. Wetherefore investigated IL-10 genotype, circulating IL-10 concentrationsand outcome in terms of organ dysfunction 24 h after cardiopulmonarybypass. Methods. Blood samples were obtained from 150 patients before,and 3, and 24 h after cardiopulmonary bypass. IL-10 wasmeasured by enzyme immunoassay. The single nucleotide polymorphismat –1082 base pairs was detected by restriction fragmentlength polymorphism analysis. Post-bypass organ system dysfunctionwas defined prospectively. Results. IL-10 concentrations were increased 3 h afterbypass (P<0.0001) and were still increased at 24 h (P<0.0001).Homozygosity for the G allele was associated with lower median(range) maximal IL-10 levels at 3 h (44 (13–136)pg ml^–1) compared with the A allele (118 (39–472)pg ml^–1; P=0.042). Those patients who developed atleast one organ dysfunction (n=33) had higher IL-10 levels 3 hafter surgery (242 (18–694) pg ml^–1) comparedwith those without organ dysfunction (77 (7–586) pg ml^–1;P=0.001, n=117). Conclusions. The G allele of the –1082 base pair singlenucleotide polymorphism in the IL-10 gene is associated withlower IL-10 release after cardiopulmonary bypass. High levelsof IL-10 secretion are associated with organ dysfunction 24 hafter surgery. Br J Anaesth 2003; 91: 424–6     

Platelet function point-of-care tests in post-bypass cardiac surgery: are they relevant?

Background. Platelet dysfunction is an important cause of excessivebleeding after cardiac surgery. We assessed two platelet functionpoint-of-care tests: the platelet function analyser (PFA-100)and the Hemostatus^TM in patients with and without excessivebleeding after cardiac surgery with cardiopulmonary bypass. Methods. Mediastinal chest tube drainage (MCTD) was measuredfor the first 6 h in the intensive care unit (ICU). Haematologyand coagulation tests were done on arrival in the ICU, and whenexcessive bleeding occurred (MCTD >1 ml kg^–1 h^–1)or after 3 h. Results. Eighteen patients bled excessively and 27 had normalMCTD. Hemostatus measurements were prolonged in those with excessivebleeding compared with the normal group. The times for PFA-100adenosine diphosphate (ADP) and epinephrine were 91 vs 71 s(P=0.004) and 155 vs 114 s (P=0.02) in the bleeding and normalgroup s, respectively. None of the Hemostatus or PFA-100 valuescorrelated with total MCTD. Depending on the agonist used, maximumaggregation was 33–81% and 52–86% in bleeding andnormal groups, respectively. Only poor correlations were foundbetween PFA-100 epinephrine and maximum aggregation in responseto ADP (r=–0.52, P=0.03) or to collagen (r=–0.48,P=0.04). Conclusion. Patients bleeding excessively in the ICU had abnormalmeasurements in point-of-care tests without a dramatic decreasein aggregation. Except for patients with increased risk of postbypassbleeding, point-of-care tests are not useful for routine useafter cardiac surgery. Br J Anaesth 2002; 89: 715–21     

Predictive perioperative factors for developing severe sepsis after major surgery

Background. Early identification of high-risk patients undergoingmajor surgery can result in an aggressive management affectingthe outcome. Methods. We designed a prospective cohort study of 93 adultpatients undergoing major oncological surgery to identify thepredictive risk factors for developing postoperative severesepsis. Results. Nineteen of 93 patients developed a severe sepsis aftersurgery; seven of the septic patients died in intensive careunit. Multivariate analysis discriminated preoperative and postoperative(first and second day after surgery) predictive risk factors.The postoperative severe sepsis was independently associatedwith preoperative factors like male gender (OR 4.7, 95% CI between1.5 and 15.5, P<0.01) and Charlson co-morbidity index (OR1.3, 95% CI between 1.07 and 1.6, P<0.01). After the surgery,the presence of systemic inflammatory response syndrome (OR4.0, 95% CI between 1.02 and 15.7, P<0.05) and a logisticorgan dysfunction score on day 2 (OR 3.3, 95% CI between 1.9and 5.7, P<0.001) were found as independent predictive factors. Conclusion. We have shown that some of the markers that canbe easily collected in the preoperative or postoperative visitscan be used to screen the patients at high risk for developingsevere sepsis after major surgery.     

Propofol and halothane versus sevoflurane in paediatric day-case surgery: induction and recovery characteristics

Background. The aim of this study was to compare the inductionand recovery characteristics associated with propofol inductionand halothane maintenance with sevoflurane anaesthesia in paediatricday surgery. Methods. In total, 322 children were assigned randomly to i.v.propofol induction and halothane/nitrous oxide maintenance orsevoflurane/nitrous oxide alone. The patients’ age, sex,and type of surgery were recorded, as were the times requiredfor anaesthetic induction, maintenance, recovery and time todischarge home. Postoperative nausea and vomiting, and the incidenceof adverse events during induction and recovery were also noted. Results. No significant differences were detected in age, sex,type of surgery performed or intraoperative opioid administration.Excitatory movement was more common during induction with sevoflurane.The mean time required for induction with propofol was 3.1 mincompared with 5 min in the sevoflurane group (P<0.001). Therecovery time was shorter in the sevoflurane group comparedwith propofol/halothane (23.2 vs 26.4 min, P<0.002). Theincidence of delirium in recovery was greater in the sevofluranegroup (P<0.001). There was no difference between groups inthe time spent on the postoperative ward before discharge home.On the postoperative ward the incidence of both nausea and vomitingwas significantly higher in the sevoflurane group (P=0.034).Five children were admitted to hospital overnight, none foranaesthetic reasons. Conclusions. The increased incidence of adverse events duringinduction, postoperative nausea and vomiting and postoperativedelirium in the sevoflurane group suggests that sevofluraneis not ideal as a sole agent for paediatric day case anaesthesia. Br J Anaesth 2003; 90: 461–6     

Differential modulation of interleukin-6 and interleukin-10 by diclofenac in patients undergoing major surgery

Background. Prostaglandins modulate cytokine release thoughincreases in cAMP, regulating interleukin (IL) 6 and IL-10.Diclofenac inhibits cyclo-oxygenase activity and hence prostaglandinproduction. We hypothesized that diclofenac would affect releaseof IL-6 and IL-10 and modulate the immune response. Methods. In a randomized, double-blind, placebo-controlled study,we investigated the effect of diclofenac in patients undergoingmajor urological surgery. Patients were randomized to receiveeither diclofenac (50 mg orally every 8 h the daybefore surgery and 75 mg i.m. every 12 h on the dayof surgery, n=23) or placebo (n=23). Standardized combined generalanaesthesia and epidural analgesia was administered. Serum IL-6,IL-10 and cortisol were measured before surgery and 30 minand 2, 6, 12 and 24 h after skin incision. Temperature,leucocyte count and C-reactive protein concentration were measuredbefore surgery and after 24 h. Results. IL-6 and IL-10 concentrations increased, reaching peaklevels at 12 and 6 h respectively in both groups. At 12 h,the IL-6 concentration was significantly lower in patients receivingdiclofenac than in those receiving placebo (P=0.003). In contrast,IL-10 concentration at 6 h was higher in diclofenac-treatedpatients (P=0.008), and this was associated with less pyrexia(P=0.03), a lower leucocyte count (P=0.0002) and a lower C-reactiveprotein concentration (P=0.0039). Serum cortisol concentrationwas similar in the two groups of patients until 24 h, whenthe concentration was lower in patients who received diclofenac(P=0.002). Cortisol concentration correlated with IL-6 concentrationat 24 h. Conclusions. Administration of diclofenac was associated withlower IL-6 and higher IL-10 concentrations, and lower leucocytecount, C-reactive protein concentration and temperature. Diclofenacmay have an anti-inflammatory role in major surgery. Br J Anaesth 2002; 88: 797–802     

Assessment of preoperative fluid depletion using bioimpedance analysis

Background. Fluid depletion during the perioperative periodis associated with poorer outcome. Non-invasive measurementof total body water by bioimpedance may enable preoperativefluid depletion and its influence on perioperative outcome tobe assessed. Methods. Weight and foot bioimpedance were recorded under standardizedconditions in patients undergoing bowel preparation (n=43) orday surgery (n=44). Fifteen volunteers also followed standardnil-by-mouth instructions on two separate occasions to assessthe variabilities of weight and bioimpedance over time. Results. Body weight fell by 1.27 kg (95% CI 1.03–1.50kg; P<0.0001) and foot bioimpedance increased by 51 ohm afterbowel preparation (95% CI 36–66; P<0.0001). Weightchange after the nil-by-mouth period in day-surgery patients(mean –0.22 kg, 95% CI –0.05 to –0.47 kg;P=0.07) correlated (r=–0.46; P=0.005) with an increasein bioimpedance (16 ohms, 95% CI 5–27 ohms; P=0.01). Nodifference between two separate bioimpedance measurements wasseen in the volunteer group. Conclusions. Further work is warranted to determine if bioimpedancechanges may serve as a useful indicator of perioperative fluiddepletion. Br J Anaesth 2004; 92: 134–6     

Intraoperative oesophageal Doppler guided fluid management shortens postoperative hospital stay after major bowel surgery

Background. Occult hypovolaemia is a key factor in the aetiologyof postoperative morbidity and may not be detected by routineheart rate and arterial pressure measurements. Intraoperativegut hypoperfusion during major surgery is associated with increasedmorbidity and postoperative hospital stay. We assessed whetherusing intraoperative oesophageal Doppler guided fluid managementto minimize hypovolaemia would reduce postoperative hospitalstay and the time before return of gut function after colorectalsurgery. Methods. This single centre, blinded, prospective controlledtrial randomized 128 consecutive consenting patients undergoingcolorectal resection to oesophageal Doppler guided or centralvenous pressure (CVP)-based (conventional) intraoperative fluidmanagement. The intervention group patients followed a dynamicoesophageal Doppler guided fluid protocol whereas control patientswere managed using routine cardiovascular monitoring aimingfor a CVP between 12 and 15 mm Hg. Results. The median postoperative stay in the Doppler guidedfluid group was 10 vs 11.5 days in the control group P<0.05.The median time to resuming full diet in the Doppler guidedfluid group was 6 vs 7 for controls P<0.001. Doppler patientsachieved significantly higher cardiac output, stroke volume,and oxygen delivery. Twenty-nine (45.3%) control patients sufferedgastrointestinal morbidity compared with nine (14.1%) in theDoppler guided fluid group P<0.001, overall morbidity wasalso significantly higher in the control group P=0.05. Conclusions. Intraoperative oesophageal Doppler guided fluidmanagement was associated with a 1.5-day median reduction inpostoperative hospital stay. Patients recovered gut functionsignificantly faster and suffered significantly less gastrointestinaland overall morbidity.     

Lack of renoprotective effect of i.v. N-acetylcysteine in patients with chronic renal failure undergoing cardiac surgery

Background. Pre-existing chronic renal failure is a significantrisk factor for acute renal failure (ARF) after cardiac surgery.N-acetylcysteine (NAC) has been shown to prevent contrast media-inducedARF. Our objective was to evaluate whether i.v. NAC has renoprotectiveeffects in patients with mild renal failure undergoing cardiacsurgery. Methods. In this prospective, randomized, double-blind study,80 patients with mild to moderate renal failure undergoing electiveheart surgery with cardiopulmonary bypass were recruited. Allreceived either i.v. NAC (n=38) or placebo (n=39) at inductionof anaesthesia and then up to 20 h. Urine N-acetyl-ß-D-glucosaminidase(NAG) and urine creatinine ratio, plasma creatinine, and serumcystatin C levels indicated renal function. Results. Levels of urinary NAG/creatinine ratio, plasma creatinineand serum cystatin C did not significantly differ between NACand placebo groups during five postoperative days. Urine NAG/creatinineratio increased over 30% in 100% of patients in the NAC groupvs 92.3% in the placebo group (P=0.081). Plasma creatinine increasedby 25% from baseline or over 44 µmol litre^–1 in42.1% in NAC group vs 48.7% in placebo group (P=0.560). Serumcystatin C exceeded 1.4 mg litre^–1 in 78.9% in NAC groupvs 61.5% in placebo group (P=0.096). Conclusions. Prophylactic treatment with i.v. N-acetylcysteinehad no renoprotective effect in patients with pre-existing renalfailure undergoing cardiac surgery.     

Prediction of the distance from skin to epidural space for low-thoracic epidural catheter insertion by computed tomography

Background. It may be clinically useful to predict the depthof the epidural space. Methods. To investigate the accuracy of preoperative abdominalcomputed tomography (CT) in prediction of the distance for low-thoracicepidural insertion, a single group observational study was conductedin 30 male patients undergoing elective major abdominal surgeryrequiring epidural analgesia for postoperative pain relief.Using the paramedian approach, low-thoracic epidural insertionat T10–11 interspace was performed with a standardizedprocedure to obtain an actual insertion length (AIL). Accordingto the principles of trigonometry, an estimated insertion length(EIL) was calculated as 1.26 times the distance from skin toepidural space measured from the preoperative abdominal CT. Results. The mean (SD) EIL and AIL were 5.5 (0.7) and 5.1 (0.6)cm, respectively, with a significant correlation (r=0.899, P<0.01).The EIL tended to have a higher value than the AIL (0.4 (0.3)cm). There were significant correlations of both EIL and AILwith weight (P<0.01), BMI (P<0.01), and body fat percentage(P<0.01), but not with height (P>0.05). Conclusions. We conclude that the preoperative abdominal CTis helpful in prediction of the distance for low-thoracic epiduralinsertion using the paramedian approach. Br J Anaesth 2004; 92: 271–3     

Articaine versus lidocaine plus bupivacaine for peribulbar anaesthesia in cataract surgery

Background. We compared the efficacy and safety of articaine2% with a mixture of lidocaine 2% and bupivacaine 0.5% withouthyaluronidase for peribulbar anaesthesia in cataract surgery. Method. In this double-blind randomized clinical study, 58 cataractpatients were allocated to receive either articaine 2% withepinephrine 1:200 000 or a mixture of equal parts of lidocaine2% with epinephrine 1.25:100 000 and bupivacaine 0.5%. Ocularand eyelid movement scores, the number of supplementary injections,total volume of solution used and pain and complications duringinjection and surgery were used as clinical end-points. Results. Articaine produced greater akinesia after 5 min (P=0.03).Eighteen patients (60%) in the articaine group and 26 (93%)in the lidocaine/bupivacaine group required a second injection(P=0.003). A third injection was needed by two patients (7%)in the articaine group and 12 (43%) in the lidocaine/bupivacainegroup (P=0.001). The total mean volume of local anaestheticrequired to achieve akinesia was mean 9.4 (SD 1.7) ml in thearticaine group and 11.28 (1.86) ml in the lidocaine/bupivacainegroup (P<0.001). Median pain score was lower in the articainegroup than in lidocaine/bupivacaine group during injection (P=0.004)and surgery (P=0.014). There was no difference between the groupsfor the incidence of complications. Conclusion. Articaine 2% without hyaluronidase is more advantageousthan a mixture of lidocaine 2% and bupivacaine 0.5% withouthyaluronidase for peribulbar anaesthesia in cataract surgery. Br J Anaesth 2004; 92: 231–4     

Spread of subarachnoid block, intraoperative local anaesthetic requirements and postoperative analgesic requirements in Caesarean section and total abdominal hysterectomy

Background. Pregnancy is associated with a higher spread ofsubarachnoid anaesthesia and increased pain threshold. The studywas designed to assess the spread of subarachnoid block andthe intra- and postoperative analgesic requirements in pregnantvs non-pregnant women. Methods. We assessed the level of subarachnoid anaesthesia after1.8 ml of hyperbaric lidocaine 5% and the postoperative analgesicrequirements in women undergoing Caesarean section and undergoingabdominal hysterectomy (30 each group). Intraoperatively epiduralropivacaine was given as required. All patients received 10ml of ropivacaine 0.2% epidurally 2, 10, and 24 h after operationand the VAS pain score was assessed. They also had access topatient controlled analgesia i.v. morphine. Results. Duration of surgery was 64 (13.7) vs 127 (33.8) min(P<0.0001) in the pregnant and non-pregnant groups. Ten minutesafter subarachnoid injection, sensory block was higher by threedermatomes in the pregnant group (P<0.0001). Time to firstropivacaine dose was 37 (19.7) vs 19 (12.2) min (P<0.001)and the ropivacaine normalized for the duration of anaesthesiawas 0.8 (0.6) vs 1.3 (0.5) mg^–1 (P=0.001) in the pregnantand non-pregnant groups, respectively. The time between thefirst and second ropivacaine dose was similar in the two groups(P=0.070). Fewer pregnant women (81 vs 100%) required ropivacaineintraoperatively (P=0.017). The VAS scores were similar butparturients consumed more i.v. morphine (33 (14) vs 24 (12)mg, P=0.016) during the first 24 h after operation. Conclusions. Pregnant patients exhibited a higher level of subarachnoidsensory block and required more i.v. morphine after operation.     

Comparison of stroke volume (SV) and stroke volume respiratory variation (SVV) measured by the axillary artery pulse-contour method and by aortic Doppler echocardiography in patients undergoing aortic surgery

Background. The goal of the study was to compare stroke volume(SV) and respiratory stroke volume variation (SVV) measuredby pulse-contour analysis and aortic Doppler. Methods. These were measured by pulse-contour analysis and thermodilution(PiCCO) and by aortic pulsed wave Doppler with transoesophagealechocardiography in patients undergoing abdominal aortic surgery.Simultaneous measurements were done at different times of surgery.All data were recorded on PiCCOwin software and videotape andanalysed off-line by a blinded investigator. Results. A total of 114 measurements were achieved in 20 patients.There was a good correlation and small bias between the PiCCOand the echo-Doppler values of the mean SV [r=0.885; bias=0.2(8) ml], and between the minimum [r=0.842; bias=1 (9) ml] andmaximum SV [r=0.840; bias=2 (10) ml] values. Conclusions. There is a fair correlation between pulse-contouranalysis and aortic Doppler for beat-by-beat measurement ofSV but not for calculation of SV respiratory ventilation.     

Effect of intrathecal tramadol administration on postoperative pain after transurethral resection of prostate

Background. Tramadol administered epidurally has been demonstratedto decrease postoperative analgesic requirements. However, itseffect on postoperative analgesia after intrathecal administrationhas not yet been studied. In this double-blind, placebo-controlledstudy, the effect of intrathecal tramadol administration onpain control after transurethral resection of the prostate (TURP)was studied. Methods. Sixty-four patients undergoing TURP were randomizedto receive bupivacaine 0.5% 3 ml intrathecally premixed witheither tramadol 25 mg or saline 0.5 ml. After operation, morphine5 mg i.m. every 3 h was administered as needed for analgesia.Postoperative morphine requirements, visual analogue scale forpain at rest (VAS) and sedation scores, times to first analgesicand hospital lengths of stay were recorded by a blinded observer. Results. There were no differences between the groups with regardto postoperative morphine requirements (mean (SD): 10.6 (7.9)vs 9.1 (5.5) mg, P=0.38), VAS (1.6 (1.2) vs 1.2 (0.8), P=0.18)and sedation scores (1.2 (0.3) vs 1.2 (0.2), P=0.89). Timesto first analgesic (6.3 (6.3) vs 7.6 (6.2) h, P=0.42) and lengthof hospital stay (4.7 (2.8) vs 4.4 (2.2) days, P=0.66) weresimilar in the two groups. Conclusion. Intrathecal tramadol was not different from salinein its effect on postoperative morphine requirements after TURP. Br J Anaesth 2003; 91: 536–40     

Gabapentin attenuates the pressor response to direct laryngoscopy and tracheal intubation

Background. Laryngoscopy and tracheal intubation increase bloodpressure and heart rate (HR). The aim of the present study wasto investigate the effect of gabapentin when given before operationon the haemodynamic responses to laryngoscopy and intubation. Methods. Forty-six patients undergoing abdominal hysterectomyfor benign disease were randomly allocated to receive gabapentin1600 mg or placebo capsules at 6 hourly intervals starting theday (noon) before surgery. Anaesthesia was induced with propofoland cis-atracurium. Systolic, diastolic arterial blood pressures(SAP, DAP) and heart rate (HR) were recorded before and afterthe anaesthetic and 0, 1, 3, 5 and 10 min after tracheal intubation. Results. SAP was significantly lower in the gabapentin vs thecontrol group 0, 1, 3, 5 and 10 min after intubation [128 (27)vs 165 (41), P=0.001, 121 (14) vs 148 (29), P=0.0001, 115 (13)vs 134 (24), P=0.002, 111 (12) vs 126 (19), P=0.004 and 108(12) vs 124 (17), P=0.001 respectively]. DAP also was lowerin the gabapentin group 0, 1, 3, and 10 min after intubation[81 (18) vs 104 (19), P=0.0001, 77 (9) vs 91 (16), P=0.001,71 (10) vs 84 (13), P=0.001 and 67 (10) vs 79 (12), P=0.004].HR did not differ between the two groups at any time [82 (11)vs 83 (15), 79 (10) vs 80 (12), 86 (17) vs 92 (10), 82 (11)vs 88 (10), 81 (12) vs 81 (11), 77 (13) vs 79 (13), and 75 (15)vs 78 (12)]. Conclusion. Gabapentin, under the present study design attenuatesthe pressor response but not the tachycardia associated withlaryngoscopy and tracheal intubation.     

Editorial IV: physical and pharmacological restraint of critically ill patients: clinical facts and ethical considerations

Background. Leucocyte-depleting arterial line filters have notdramatically improved lung function after cardiopulmonary bypass(CPB), but patients with pre-existing lung dysfunction may benefitfrom their use. Methods. We randomized 32 patients with mild lung dysfunctionhaving elective first-time coronary revascularization to eithera leucocyte depleting or a standard 40-mm arterial line filterduring CPB. The alveolar arterial oxygenation index was calculatedbefore and 5 min after CPB, then at 1, 2, 4, 8, and 18 h aftersurgery. Time to extubation on the ITU was recorded. Preoperative,immediate postoperative, and 24 h postoperative chest x-rayswere scored for extravascular lung water. Results. Postoperative alveolar–arterial oxygenation indiceswere better in the patients who received leucocyte depletionduring CPB (1.65±0.96 in the study group vs 2.90±1.72in the control group, P<0.05). The duration of postoperativemechanical ventilation was less in the leucocyte-depleted group(4.8±2.1 vs 8.3±4.7 h in the control group, P<0.05).The extravascular lung water scores immediately postoperativelywere 13.0±8.6 in the study group vs 19.6±10.8in the control group (P=0.04), and at 24 h postoperatively,9.7±7.7 vs 15.2±9.9 for controls. Conclusions. For patients with mild lung dysfunction, a leucocyte-depletingarterial line filter improves postoperative oxygenation, reducesextravascular lung water accumulation, and reduces time on artificialventilator after CPB. There may be an economic argument forthe routine use of leucocyte-depleting filters for every patientduring CPB.     

Randomized double-blind clinical trial comparing topical and sub-Tenon's anaesthesia in routine cataract surgery

Background. Several local anaesthetic techniques are availablefor cataract surgery. Recently, topical anaesthesia has gainedin popularity. A randomized trial was designed to compare patientdiscomfort and intraoperative complications following routinecataract surgery under topical or sub-Tenon's anaesthesia. Methods. A randomized double-blinded placebo-controlled clinicaltrial of 210 patients assigned to either a sub-Tenon's group(sub-Tenon's anaesthesia with placebo topical balanced saltsolution, n=140) or a topical anaesthesia group (topical anaesthesiawith placebo sub-Tenon's injection of balanced salt solution,n=70) was carried out. All patients underwent phacoemulsificationwith intraocular lens implantation. Patients in the sub-Tenon'sgroup received a single injection (3 ml) of a combination oflidocaine 2% (2 ml) and bupivacaine 0.75% (1 ml), and four dosesof topical placebo (balanced salt solution). Patients in thetopical anaesthesia group received four doses of topical proxymethocaine0.5% and a placebo sub-Tenon's injection (3 ml) of balancedsalt solution. No intracameral injection of local anaestheticwas given. A 10-point visual analogue pain scale was used preoperativelyand for postoperative pain assessment immediately after theoperation and 30 min postoperatively. The intraoperative complicationsin the two groups were recorded. Results. The mean pain score immediately after surgery was 2.42(SD 2.2) in the sub-Tenon's group and 3.44 (2.3) in the topicalanaesthesia group (P=0.0043). The mean pain score 30 min aftersurgery was 1.24 (1.7) in the sub-Tenon's group and 2.25 (2.2)in the topical anaesthesia group (P=0.0009). Conclusions. Patients undergoing cataract surgery under topicalanaesthesia experience more postoperative discomfort than patientsreceiving sub-Tenon's anaesthesia. Surgery-related complicationswere similar in both groups.      

Preconditioning effects of levosimendan in coronary artery bypass grafting--a pilot study

Background. The calcium sensitizer levosimendan protects againstmyocardial ischaemia and reperfusion injury in animal models. Methods. The present pilot study investigated whether a shortinfusion before coronary artery bypass grafting (CABG) wouldprotect the myocardium and improve postoperative haemodynamics.Twenty-four patients with stable angina undergoing electiveCABG surgery were randomized to receive either placebo or levosimendan(24 µg kg^–1) infused i.v. over a 10 min period justbefore placing the patient on cardiopulmonary bypass. Results. Perioperative haemodynamic variables, concentrationsof cardiac troponin I over the 48 h postoperative period, andclinical outcomes were assessed. There were no adverse effectsrelated to levosimendan. Compared with control patients, levosimendan-treatedpatients had lower postoperative troponin I concentrations (P<0.05)and a higher cardiac index (P<0.05). Conclusion. Patients receiving a short infusion of levosimendanbefore CABG showed evidence of less myocardial damage, suggestiveof a preconditioning effect. Larger outcome studies are thusindicated to confirm benefit.      

Haemodynamic and renal effects of intravenous enalaprilat during coronary artery bypass graft surgery in patients with ischaemic heart dysfunction

Renal dysfunction occurring after open heart surgery is multifactorialin origin but activation of the renin–angiotensin systemmay have a prominent role. Fourteen patients with ischaemicheart dysfunction scheduled for elective coronary artery bypassgraft (CABG) surgery were allocated to a treatment group [enalaprilatfor 2 days; ACEI (angiotensin-converting enzyme inhibitor) group,n=7] or a control group (n=7). The cardiac index was significantlyhigher in ACEI-treated patients than in the controls beforeand after cardiopulmonary bypass (CPB) (P<0.05) and on postoperativeday 2 (P<0.05). The systemic vascular resistance wassignificantly lower in the ACEI-treated patients than in thecontrols before and after CPB (P<0.05). Renal plasma flow,measured as [¹³¹I]orthoiodohippuran clearance (Cl_H), was higherin the ACEI group than in the control group before CPB, as wasendogenous creatinine clearance after CPB (P<0.05). On post-operativeday 7, Cl_H was significantly higher in the ACEI group thanin the control group (P<0.05). Plasma renin activity andvasopressin concentration increased in both groups during CPB(P<0.05). The study demonstrates that administration of ani.v. ACEI, enalaprilat, improves cardiac output during CABGsurgery in patients with ischaemic heart dysfunction. Moreover,renal perfusion was better maintained during surgery, and thiseffect was sustained up to post-operative day 7. Br J Anaesth 2001; 86: 169–75     

Emergence delirium in adults in the post-anaesthesia care unit

Background. Emergence delirium in the post-anaesthesia careunit (PACU) is poorly understood. The goal of this prospectivestudy was to determine frequency and risk factors of emergencedelirium in adults after general anaesthesia. Methods. In this prospective study, 1359 consecutive patientswere included. Contextual risk factors and occurrence of deliriumaccording to the Riker sedation scale were documented. Groupswere defined for the analysis according to the occurrence ornot of agitation, then after exclusion of patients with preoperativeanxiety and neuroleptics, or both, and antidepressants or benzodiazepinestreatments. Results. Sixty-four (4.7%) patients developed delirium in thePACU, which can go from thrashing to violent behaviour and removalof tubes and catheters. Preoperative anxiety was not found tobe a risk factor. Preoperative medication by benzodiazepines(OR=1.910, 95% CI=1.101–3.315, P=0.021), breast surgery(OR=5.190, 95% CI=1.422–18.947, P=0.013), abdominal surgery(OR=3.206, 95% CI=1.262–8.143, P=0.014), and long durationof surgery increased the risk of delirium (OR=1.005, 95% CI=1.002–1.008,P=0.001), while a previous history of illness and long-termtreatment by antidepressants decreased the risk (respectively,OR=0.544, 95% CI=0.315–0.939, P=0.029 and OR=0.245, 95%CI=0.084–0.710, P=0.010). Conclusions. Preoperative benzodiazepines, breast and abdominalsurgery and surgery of long duration are risk factors for emergencedelirium.