Analgesic efficacy of rectal acetaminophen and ibuprofen alone or in combination for paediatric day-case adenoidectomy

Background. Acetaminophen and non-steroidal anti-inflammatorydrugs have different mechanisms of action. We investigated ifcombining rectal acetaminophen with ibuprofen would providebetter postoperative analgesia compared with either drug aloneafter adenoidectomy in children. Methods. 160 children, aged 1–6 yr, undergoing day-caseadenoidectomy, were randomized to receive either acetaminophen40 mg kg^–1, ibuprofen 15 mg kg^–1, their combination,or placebo rectally immediately after anaesthetic induction.A standard anaesthetic method was used and all children receivedalfentanil 10 µg kg^–1 i.v. during induction. Meperidine5–10 mg i.v. was used for rescue analgesia for a painscore (Objective Pain Scale) over 3. Recovery times, sedationscores and the need for rescue analgesia and adverse eventsduring the first 24 h after anaesthesia were recorded. Rescueanalgesic at home was ibuprofen 10 mg kg^–1. Results. Total meperidine requirements were significantly lessin the groups receiving acetaminophen, ibuprofen, or their combinationcompared with the group receiving placebo indicating an opioid-sparingeffect of 19–28% (P<0.05). Children given acetaminophenwere more sedated than those given ibuprofen (P<0.05). Dischargecriteria were fulfilled earlier in the ibuprofen group thanin all the other groups (P<0.05). At home, less children(49%) needed rescue analgesia in the combination group comparedwith the other groups (74–77%) (P<0.02). Conclusions. We conclude that prophylactically administeredrectal acetaminophen combined with ibuprofen does not improveanalgesia after adenoidectomy in the immediate postoperativeperiod compared with either drug alone but does decrease theneed for analgesia at home. Ibuprofen results in lesser sedationand faster discharge than when acetaminophen is used. Br J Anaesth 2003; 91: 363–7     

Parecoxib sodium has opioid-sparing effects in patients undergoing total knee arthroplasty under spinal anaesthesia

Background. This multicentre, double-blind, placebo-controlledstudy compared the opioid-sparing effectiveness and clinicalsafety of parecoxib sodium over 48 h, in 195 postoperativepatients after routine total knee replacement surgery. Methods. Elective total primary knee arthroplasty was performedunder spinal anaesthesia, with a single dose of spinal bupivacaine10–20 mg, and intraoperative sedation with midazolam0.5–1.0 mg i.v., or propofol <6 mg kg^–1h^–1. Patients were randomized to receive either parecoxibsodium 20 mg twice daily (bd) i.v. (n=65), parecoxib sodium40 mg bd i.v. (n=67), or placebo (n=63) at the completionof surgery, and after 12, 24, and 36 h. Morphine (1–2 mg)was taken by patient-controlled analgesia or by bolus dosesafter 30 min. Results. Patients receiving parecoxib sodium 20 mg bd and40 mg bd consumed 15.6% and 27.8% less morphine at 24 hthan patients taking placebo (both P<0.05). Both doses ofparecoxib sodium administered with morphine provided significantlygreater pain relief than morphine alone from 6 h (P<0.05).A global evaluation of study medication demonstrated a greaterlevel of satisfaction among patients taking parecoxib sodiumthan those taking placebo. Parecoxib sodium administered incombination with morphine was well tolerated. However, a reductionin opioid-type side-effects was not demonstrated in the parecoxibsodium groups. Conclusion. Parecoxib sodium provides opioid-sparing analgesiceffects in postoperative patients. Br J Anaesth 2003; 90: 166–72     

Effect of obesity and thoracic epidural analgesia on perioperative spirometry

Background. Lung volumes in obese patients are reduced significantlyin the postoperative period. As the effect of different analgesicregimes on perioperative spirometric tests in obese patientshas not yet been studied, we investigated the effect of thoracicepidural analgesia and conventional opioid-based analgesia onperioperative lung volumes measured by spirometry. Methods. Eighty-four patients having midline laparotomy forgynaecological procedures successfully completed the study.Premedication, anaesthesia and analgesia were standardized.The patients were given a free choice between epidural analgesia(EDA) (n=42) or opioids (n=42) for postoperative analgesia.We performed spirometry to measure vital capacity (VC), forcedvital capacity, peak expiratory flow, mid-expiratory flow andforced expiratory volume in 1 s at preoperative assessment,30–60 min after premedication and 20 min, 1 h, 3 h and6 h after extubation. Results. Baseline values were all within the normal range. Allperioperative spirometric values decreased significantly withincreasing body mass index (BMI). The greatest reduction inVC occurred directly after extubation, but was less in the EDAgroup than in the opioid group: mean of –23(SD 8)% versus–30(12)% (P<0.001). In obese patients (BMI>30) thedifference in VC was significantly more pronounced than in patientsof normal weight (BMI<25): –45(10)% versus –33(4)%(P<0.001). Recovery of spirometric values was significantlyquicker in patients receiving EDA, particularly in obese patients. Conclusion. We conclude that EDA should be considered in obesepatients undergoing midline laparotomy to improve postoperativespirometry.     

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     

Low-dose droperidol reduces postoperative vomiting in paediatric day surgery

In a prospective, randomized, blind study, we assessed the effectivenessof droperidol 20 µg kg^–1 i.v., given at inductionof anaesthesia, in preventing postoperative vomiting in paediatricday-case patients. We studied 270 children, aged 1–15yr. undergoing body surface surgery. There was a significantreduction in the incidence of vomiting in the recovery room(1.4% vs 9.2%, P < 0.005) and in the day ward (9.4% vs 18.3%,P < 0.05) in patients receiving droperidol. There was nosignificant difference on the journey home (9.5% vs 17.83%,ns) or at home (16.7% vs 10.3%, ns). There was also a reductionin the severity of vomiting in the droperidol group. There wereno adverse side effects. (Br. J. Anaesth. 1995; 74: 509–511)     

A registry of haemodialysis patients and the progress of haemodialysis services in Lithuania.

Background. Until 1990, haemodialysis (HD) in Lithuania wasunderdeveloped, but after independence, development of HD started.Until 1996, no precise data about HD patients in Lithuania wereavailable. In order to create a registry of HD, we started tocollect data about dialysis services and HD patients in 1996.Every collection of data was followed by distribution and discussionof the results within the nephrological community. This studydescribes the changes of Lithuanian HD between 1996–2002. Methods. Between 1996 till 2002 all HD centres in Lithuaniawere annually visited and data were collected about all HD patients(response rate of 100%). The evaluation of the results duringour observational study was made according to the European BestPractice Guidelines. During annual conferences for nephrologists,the guidelines and data of our HD registry were presented. Results. There was an increase in the number of HD stations(from 25 p.m.p. to 75 p.m.p., P<0.001), in HD patients (from60 p.m.p. to 237 p.m.p., P<0.001) and in the incidence ofnew HD patients (from 54.3 p.m.p. to 103 p.m.p., P<0.01).The mean age of HD patients increased from 47.2±16.1years in 1996 to 56.0±14.9 in 2002 (P<0.001). Themain underlying cause of ESRD was chronic glomerulonephritis,but its rate decreased from 54.5% in 1996 to 27.5% in 2002 (P<0.001).The percentage of diabetics increased from 7.1% to 16.4%, P<0.05,and in hypertensive nephropathy from 3.1% to 10.9%, P<0.05.We observed improvement of the quality of HD in Lithuania duringthese 5 years. The percentage of patients on bicarbonate HDincreased from 7.1% in 1996 to 100% in 2002 (P<0.001). Thepercentage of patients receiving more than 12 h HD/week increasedfrom 30.8% in 1996 to 53.5% in 2002 (P<0.001). The mean Kt/Vin 1999 was 0.81±0.53, but it increased in 2002 to 1.22±0.27,P<0.001. In 2002, 84.6% of all HD patients were examinedfor HB_sAg, 82.3% for anti–HCV, 31.2% for anti-HB_s and57.1% for anti-HB_c. The percentage of patients receiving phosphatebinders increased from 65.2% in 1996 to 84.4% in 1997 and 90.5%in 2002. Serum parathyroid hormone (PTH) levels were measuredin 27.3% of HD patients in 1999 but in 85.2% of patients in2002. The mean haemoglobin (Hb) concentration increased from92±15.4 g/l to 105±14.7 g/l; the percentage ofpatients with Hb>100 g/l increased from 27.5% to 64% in 2001.The percentage of HD patients receiving epoetin was 94.6% in2001 as compared with 78% in 1997. There was a marked increasein the use of intravenous iron (from 7.5% patients in 1997 to70.8% in 2000). The mean weekly dose of Epo was lower in HDpatients receiving intravenous iron than in patients receivingoral iron. Conclusions. Over the period of 1996–2002 the HD servicessignificantly expanded in Lithuania. The introduction of EuropeanBest Practice Guidelines and the establishment of a HD registrywith feedback of the results stimulated the significant progressin the quality of HD and in the management of the patients.     

Extreme value theory applied to postoperative breathing patterns

Background. There has been little published work on the statisticalfeatures of breath times in postoperative patients. We appliedextreme value theory (a statistical method) to the variationin the timing of postoperative breathing. Methods. We observed 49 patients 3–6 h after a varietyof surgical procedures, once they had achieved a stable breathingpattern. The breathing patterns could be one of the three typespredicted by the extreme value model. ‘Finite’ breathingpatterns (n=30) have a finite upper limit of duration for anyapnoea. Patients that displayed one of the other two patterns(‘standard’ and ‘extended’) have, potentially,no limit in duration of apnoea. Results. The type of breathing pattern observed in each patientwas not reliably identified by most of the commonly used riskfactors (age, type of surgery, opioid type, dose, and routeof administration). A finite pattern was observed in 13 of 26patients receiving epidural (vs 17 of 23 parenteral analgesia:P=0.15), and 15 of 19 receiving morphine (vs 15 of 30 otheropioids: P=0.05). The patients with ‘finite’ patternswere also significantly less drowsy (score 1.04 (0.92) vs 1.62(0.62), P<0.05). Conclusions. The breathing pattern was not related to mean breathtimes, suggesting that the prevalence of apnoeas cannot be reliablypredicted by measurement of the respiratory rate alone. Br J Anaesth 2002; 88: 61–4     

Effects of remifentanil and alfentanil on the cardiovascular responses to induction of anaesthesia and tracheal intubation in the elderly

Background. We compared the effects of remifentanil and alfentanilon arterial pressure and heart rate at induction of anaesthesiaand tracheal intubation in 40 ASA I–III patients agedgreater than 65 yr, in a randomized double-blind study. Methods. Patients received either remifentanil 0.5 µgkg^–1 over 30 s, followed by an infusion of 0.1 µgkg min^–1 (group R) or alfentanil 10 µg kg^–1over 30 s, followed by an infusion of saline (group A). Anaesthesiawas then induced with propofol, rocuronium, and 1% isofluranewith 66% nitrous oxide in oxygen. Results. Systolic arterial pressure (SAP) and mean arterialpressure (MAP) decreased after the induction of anaesthesia(P<0.05) and increased for 3 min after intubation in bothgroups (P<0.05), but remained below baseline values throughout.Heart rate remained stable after induction of anaesthesia butincreased significantly from baseline after intubation for 1and 4 min in groups R and A, respectively (P<0.05). Therewere no significant between-group differences in SAP, MAP, andheart rate. Diastolic pressure was significantly higher in groupA than group R at 4 and 5 min after intubation (P<0.05).Hypotension (SAP <100 mm Hg) occurred in four patients ingroup R and three patients in group A. Conclusions. Remifentanil and alfentanil similarly attenuatethe pressor response to laryngoscopy and intubation, but theincidence of hypotension confirms that both drugs should beused with caution in elderly patients. Br J Anaesth 2002; 88: 430–3     

Optimizing fluid therapy in mechanically ventilated patients after cardiac surgery by on-line monitoring of left ventricular stroke volume variations. Comparison with aortic systolic pressure variations

Background. Mechanical ventilation causes changes in left ventricularpreload leading to distinct variations in left ventricular strokevolume and systolic arterial pressure. Retrospective off-linequantification of systolic arterial pressure variations (SPV)has been validated as a sensitive method of predicting leftventricular response to volume administration. We report thereal-time measurement of left ventricular stroke volume variations(SVV) by continuous arterial pulse contour analysis and compareit with off-line measurements of SPV in patients after cardiacsurgery. Methods. SVV and SPV were determined before and after volumeloading with colloids in 20 mechanically ventilated patients. Results. SVV and SPV decreased significantly after volume loadingand were correlated (r=0.89; P<0.001). Changes in SVV andchanges in SPV as a result of volume loading were also significantlycorrelated (r=0.85; P<0.005). Changes in SVV correlated significantlywith changes in stroke volume index (SVI) (r=0.67; P<0.005)as did changes in SPV (r=0.56; P<0.05). SVV determined beforevolume loading correlated significantly with changes in SVI(R=0.67; P <0.005). Using receiver operating characteristicscurves, the area under the curve was statistically greater forSVV (0.824; 95% confidence interval: [CI] 0.64–1.0) andSPV (0.81; CI: 0.62–1.0) than for central venous pressure(0.451; CI: 0.17–0.74). Conclusions. Monitoring of SVV enables real-time predictionand monitoring of the left ventricular response to preload enhancementin patients after cardiac surgery and is helpful for guidingvolume therapy. Br J Anaesth 2002; 88: 124–6     

Comparison of ropivacaine 0.5% (in glucose 5%) with bupivacaine 0.5% (in glucose 8%) for spinal anaesthesia for elective surgery

Background. Hyperbaric solutions of ropivacaine have been usedsuccessfully to provide spinal anaesthesia. This study was designedto compare the clinical efficacy of hyperbaric ropivacaine withthat of the commercially available hyperbaric preparation ofbupivacaine. Methods. Forty ASA grade I–II patients undergoing lower-abdominal,perineal or lower-limb surgery under spinal anaesthesia wererecruited and randomized to receive ropivacaine 5 mg ml^–1(with glucose 50 mg ml^–1), 3 ml or bupivacaine 5 mg ml^–1(with glucose 80 mg ml^–1), 3 ml. The level and durationof sensory block, intensity and duration of motor block, andtime to mobilize and micturate were recorded. Patients wereinterviewed at 24 h and at 1 week to identify any residual problems. Results. All blocks were adequate for the proposed surgery,but there were significant differences between the two groupsin mean time to onset of sensory block at T10 (ropivacaine 5min; bupivacaine 2 min; P<0.005), median maximum extent (ropivacaineT7; bupivacaine T5; P<0.005) and mean duration of sensoryblock at T10 (ropivacaine 56.5 min; bupivacaine 118 min; P=0.001).Patients receiving ropivacaine mobilized sooner (ropivacainemean 253.5 min; bupivacaine 331 min; P=0.002) and passed urinesooner (ropivacaine mean 276 min; bupivacaine 340.5 min; P=0.01)than those receiving bupivacaine. More patients in the bupivacainegroup required treatment for hypotension (>30% decrease insystolic pressure; P=0.001). Conclusions. Ropivacaine 15 mg in glucose 50 mg ml^–1 providesreliable spinal anaesthesia of shorter duration and with lesshypotension than bupivacaine. The recovery profile for ropivacainemay be of interest given that more surgery is being performedin the day-case setting. Br J Anaesth 2003; 90: 304–8     

Comparison of phenylephrine infusion regimens for maintaining maternal blood pressure during spinal anaesthesia for Caesarean section

Background. During spinal anaesthesia for Caesarean section,the optimal phenylephrine regimen and the optimal blood pressure(BP) to which it should be titrated are undetermined. The idealregimen would balance efficacy for maintaining uteroplacentalperfusion pressure against potential for uteroplacental vasoconstriction,both of which may affect fetal acid–base status. We comparedphenylephrine infusion regimens based on three different BPthresholds. Methods. After intrathecal injection, we infused phenylephrine100 µg min^–1 for 2 min. Then, until delivery,we infused phenylephrine whenever systolic BP (SBP), measuredevery 1 min, was below a randomly assigned percentage of baseline:100% (Group 100, n=25), 90% (Group 90, n=25) or 80% (Group 80,n=24). We compared umbilical blood gases, Apgar scores and maternalhaemodynamics and symptoms. Results. Patients in Group 100 had fewer episodes [median 0(range 0–8)] of hypotension (SBP <80% baseline) comparedwith Group 80 [5 (0–18)] and Group 90 [2 (0–7)](P<0.001 in each instance). Total dose of phenylephrine wasgreater in Group 100 [median 1520 µg (interquartile range1250–2130 µg)] compared with Group 90 [1070 (890–1360)µg] and Group 80 [790 (590–950) µg]. Umbilicalarterial pH was greater in Group 100 [mean 7.32 (95% confidenceinterval 7.31–7.34)] than in Group 80 [7.30 (7.28–7.31)](P=0.034). No patient had umbilical arterial pH <7.2. InGroup 100, 1/24 (4%) patients had nausea or vomiting comparedwith 4/25 (16%) in Group 90 and 10/25 (40%) in Group 80 (P=0.006). Conclusions. For optimal management, phenylephrine should betitrated to maintain maternal BP at near-baseline values. Br J Anaesth 2004; 92: 469–74     

Comparison of four strategies to reduce the pain associated with intravenous administration of rocuronium

Background. I.V. rocuronium produces intense discomfort at thesite of injection in conscious patients. Four strategies toreduce or prevent this discomfort were studied. Methods. Two hundred and fifty adult patients, ASA I–III,were randomized into five groups of 50 patients in a blinded,prospective study. The control group received rocuronium 10 mgalone. For the remaining four groups, rocuronium 10 mgwas mixed with sodium bicarbonate 8.4% 2 ml, fentanyl 100 µg,lidocaine 2% or normal saline. The pH and osmolality of allmixtures were measured. Patient data were analysed using ordinallogistic regression. Osmolality and pH data were analysed usingthe Kruskal–Wallis test with Dunn’s multiple comparisontest. Results. When compared with rocuronium alone, only the additionof saline failed to significantly reduce the pain reported bypatients. The addition of fentanyl reduced the complaint ofpain by 1.9 times (P<0.049) and the addition of lidocaine2% reduced it by 3.6 times (P<0.0001). Sodium bicarbonate8.4% reduced the reporting of pain by 18.4 times (P<0.0001). Conclusions. Sodium bicarbonate 8.4%, when added to rocuronium,markedly reduces the experience of pain during the i.v. administrationof a small dose of rocuronium. Br J Anaesth 2003; 90: 377–9     

Antiemetic and analgesic-sparing effects of diphenhydramine added to morphine intravenous patient-controlled analgesia

Background. This study was designed to examine the analgesicand dose-related antiemetic efficacy of diphenhydramine–morphinemixture for intravenous patient-controlled analgesia (PCA). Methods. Healthy women, undergoing abdominal total hysterectomywere recruited to this double-blinded randomized placebo-controlledstudy. Patients were randomly allocated to one of three groups(n=40 each). In group 1, patients received saline at inductionand morphine 1 mg ml^–1 alone for postoperative PCA. Patientsin groups 2 and 3 received diphenhydramine 30 mg i.v. at inductionand were given a 1.2:1 or a 4.8:1 ratio, respectively, of diphenhydramine–morphinemixture for postoperative PCA. Results. A total of 112 patients completed the study. The incidenceof postoperative nausea (31.6% vs 67.6%, P<0.01) and vomiting(15.8% vs 40.5%, <0.05) was significantly lower in group3 than in group 1. Furthermore, the incidence of severe nauseawas significantly lower in group 3 than in group1 (2.6% vs 24.3%,P<0.05). The rescue antiemetic requirements were also significantlyless in group 3 than in group 1 (5.3% vs 24.3%, P<0.05).However, there was no significant difference between group 2and group 1 in any of the comparisons. Pain intensity, 24-hmorphine consumption and diphenhydramine-related side-effects,such as sedation or dry mouth, did not differ among the threegroups. Conclusion. An initial bolus of diphenhydramine 30 mg at anaestheticinduction followed by postoperative PCA with a 4.8:1, but not1.2:1, diphenhydramine–morphine mixture provides an effectiveantiemetic efficacy without morphine-sparing effects.     

Auditory evoked response during propofol anaesthesia after pre-induction with midazolam

Background. In clinical use, midazolam reduces the dose requirementfor propofol. We studied the effect of midazolam given beforeanaesthesia on the amount of propofol needed and the time taken,to achieve loss of consciousness (LOC) in 20 patients. Methods. We compared the auditory evoked responses (AER) inthese patients with those in a group of 20 patients who werenot given midazolam. Results. LOC, as defined by a loss of response to verbal commandand eyelash reflex, occurred after 113 (95% CI, 99–131)s in the control group and 75 (56–101) s in the midazolamgroup (P<0.05). In the control group 2.3 (2.0–2.6)mg kg^–1 propofol caused LOC compared with 1.3 (1.1–1.5)mg kg^–1 in the group pretreated with midazolam (P<0.001).Pa amplitude decreased by 60% in the control group and by 54%in the midazolam group while Nb latency increased by 24% inthe control group and by 32% in the midazolam group followingLOC. These differences were not significant. Conclusions. We confirmed that coinduction of anaesthesia withmidazolam and propofol reduces the requirement of propofol.We also demonstrated that the AER reflects anaesthetic depthrather than plasma concentrations of anaesthetic drugs. Br J Anaesth 2002; 89: 325–7     

Lactic acidosis in the rectal lumen of patients with septic shock measured by luminal equilibrium dialysis

Background. Gut ischaemia may contribute to morbidity in sepsis,but little is known about the metabolic state of the gut mucosain such patients. Methods. Nine patients with abdominal septic shock treated withnorepinephrine, and ten healthy subjects, were subjected toequilibrium dialysis with a rectal balloon. pH, PCO₂ and concentrationsof L-lactate were measured by auto-analyser. Results. In rectal dialysis fluid from patients with septicshock, acidosis was present (pH 7.23, 95% CI 7.11–7.36)and concentrations of L-lactate were approximately five timesgreater than controls (2.5–5.8 vs 0.5–1.2 mmollitre^–1). The lactate concentration was related to thedose of norepinephrine (P<0.001). In contrast, values ofdialysate PCO₂ did not differ significantly between patientsand controls (6.4–11.0 vs 8.9–13.8 kPa). Conclusions. The results suggest that, either lactic acidosisin rectal mucosa is related to shock severity, or that norepinephrinecauses mucosal ischaemia. In any case, metabolic dysfunctionis present in the rectal mucosa in patients with abdominal septicshock treated with norepinephrine. Br J Anaesth 2002; 89: 919–22     

Autoantibodies against N-homocysteinylated proteins in patients on long-term haemodialysis

Background. Autoantibodies against N-homocysteinylated (N-Hcy)proteins at high titres have been demonstrated in patients withpremature coronary artery disease (CAD) and stroke. Since recently,elevated N-Hcy-proteins levels have been reported in haemodialysispatients, we sought to investigate whether anti-N-Hcy-proteinantibodies occur in such subjects and if they are associatedwith cardiovascular risk. Methods. We studied 43 patients, aged 27–89 (mean 58.8)years, dialysed for, on average, 50 months and 31 age- and sex-matchedhealthy controls. IgG antibodies against N-Hcy-albumin and -haemoglobinwere determined using an in-house enzyme-linked immunosorbentassay. Results. Haemodialysis patients had higher plasma tHcy (23.18± 1.37 vs 13.51 ± 0.64; P < 0.0001), serumfolate (29.7 ± 6.9 vs 9.9 ± 3.8 nmol/l; P <0.0001) and anti-N-Hcy-albumin and -haemoglobin antibodies (absorbancyat 490 nm: 0.39 ± 0.22 vs 0.34 ± 0.12; P = 0.03and 0.60 ± 0.31 vs 0.42 ± 0.09; P < 0.0001,respectively) than controls. Levels of anti-N-Hcy-albumin antibodies,but not those against haemoglobin, correlated negatively withthe duration of haemodialysis (r = –0.39; P = 0.01). Thiscorrelation disappeared after a 6-month follow-up. Haemodialysispatients treated with folic acid on a long-term basis had similarlevels of anti-N-Hcy-albumin and -haemoglobin antibodies comparedwith the minority which denied taking this vitamin (absorbancyA490: 0.35 ± 0.22 vs 0.38 ± 0.05; P = 0.5 and0.63 ± 0.30 vs 0.51 ± 0.11; P = 0.4, respectively). Conclusions. Our study shows that an autoimmune response toanti-N-Hcy-proteins occurs in patients on maintenance haemodialysisand is more pronounced than in healthy subjects.     

Prospective randomized controlled trial of acute normovolaemic haemodilution in major gastrointestinal surgery

Background. The efficacy of acute normovolaemic haemodilution(ANH) remains uncertain because of a lack of well-designed prospectiverandomized controlled trials. The aim of this study was to assessthe effects of ANH on allogeneic transfusion, postoperativecomplications, and duration of stay. Methods. Consecutive patients undergoing major gastrointestinalsurgery were randomized to a planned 3-unit ANH, or no ANH.Both groups underwent identical management including adherenceto a transfusion protocol after surgery. Outcome measures includedthe number of patients receiving allogeneic blood, complications,and duration of stay. Results. 380 patients were screened of which 160 were includedin the study, median age was 62 yr (range 23–90), ‘ANH’n=78, ‘no ANH’ n=82. There was no significant differencebetween groups in the number of patients receiving allogeneicblood 22/78 (28%) vs 25/82 (30%), the total number of allogeneicunits transfused (90 vs 93), complication rate, or durationof stay. Haemodilution significantly increased anaesthetic time,median 55 (range 15–90) vs 40 min (range 17–80)(P<0.001). Significantly fewer patients in the ANH groupexperienced oliguria in the immediate postoperative period 37/78(47%) vs 55/82 (67%) (P=0.012). The most significant factorsaffecting transfusion were blood loss, starting haemoglobin,and age. When compared with ASA-matched historical controls,the introduction of a transfusion protocol reduced the transfusionrate in colorectal patients from 136/333 (41%) to 37/138 (27%),P=0.004. Conclusions. In this large pragmatic study, ANH did not affectallogeneic transfusion rate in major gastrointestinal surgery.Preoperative haemoglobin, blood loss, and transfusion protocolare the key factors influencing allogeneic transfusion.     

Assessing fluid responsiveness during open chest conditions

Background. Measurement of ventilation-induced left ventricularstroke volume variations (SVV) or pulse pressure variations(PPV) is useful to optimize preload in patients after cardiacsurgery. The aim of this study was to investigate the abilityof SVV and PPV measured by arterial pulse contour analysis toassess fluid responsiveness in patients undergoing coronaryartery bypass surgery during open-chest conditions. Methods. We studied 22 patients immediately after midline sternotomy.We determined SVV, PPV, left ventricular end-diastolic areaindex by transoesophageal echocardiography, global end-diastolicvolume index and cardiac index by thermodilution before andafter removal of blood 500 ml and after volume substitutionwith hydroxyethyl starch 6%, 500 ml. Results. Blood removal resulted in a significant increase inSVV from 6.7 (2.2) to 12.7 (3.8)%. PPV increased from 5.2 (2.5)to 11.9 (4.6)% (both P<0.001). Cardiac index decreased from2.9 (0.6) to 2.3 (0.5) litres min^–1 m^–2 and globalend-diastolic volume index decreased from 650 (98) to 565 (98)ml m^–2 (both P<0.025). Left ventricular end-diastolicarea index did not change significantly. After fluid loadingSVV decreased significantly to 6.8 (2.2)% and PPV decreasedto 5.4 (2.1)% (both P<0.001). Concomitantly, cardiac indexincreased significantly to 3.3 (0.5) litres min^–1 m^–2(P<0.001) and global end-diastolic volume index increasedsignificantly to 663 (104) ml m^–2 (P<0.005). Left ventricularend-diastolic area index did not change significantly. We founda significant correlation between the increase in cardiac indexcaused by fluid loading and SVV as well as PPV before fluidloading (SVV, R=0.74, P<0.001; PPV, R=0.61, P<0.005).No correlations were found between values of global end-diastolicvolume index or left ventricular end-diastolic area index beforefluid loading and the increase in cardiac index. Conclusion. Measurement of SVV or PPV allows assessment of fluidresponsiveness in hypovolaemic patients under open-chest andopen-pericardium conditions. Thus, measuring heart–lunginteractions may improve haemodynamic management during surgicalprocedures requiring mid-line sternotomy.     

Respiratory response to skin incision during anaesthesia with infusions of propofol and alfentanil

Background. The ventilatory response to skin incision duringanaesthesia with enflurane is an increase in tidal volume withouta change in frequency. As opioids affect respiratory frequencyand also affect the processing of pain, we investigated if thebreathing response to a painful stimulus could be differentduring anaesthesia using opioids. Methods. We studied 12 patients during anaesthesia with target-controlledinfusions of propofol (plasma target concentration 4–6 µg ml^–1)and alfentanil (plasma target concentration 40–60 ng ml^–1),having varicose vein surgery. Results. After the initial skin incision, tidal volume increasedpromptly by 17 (4, 81)% (median, quartile values) (P<0.01).Respiratory frequency changed variably with no significant changeoverall [median change 2 (–8, +50)%]. The duration ofinspiration was virtually unaltered, and the duration of expirationdecreased gradually by 5 (–7, 32)%. Patients who showedmore response also showed more change in tidal volume, so thatthere was a significant relationship between increased inspiratoryflow rate and reduced expiratory time (P<0.05). Conclusions. During opioid anaesthesia, the mechanism of ventilatoryincrease after stimulation involves changes in both drive andtiming of breathing. This pattern of response does not resemblethe changes seen during anaesthesia with potent volatile agents. Br J Anaesth 2002; 88: 649–52     

Randomized study comparing the effects of hydroxyethyl starch solution with Gelofusine on pulmonary function in patients undergoing abdominal aortic aneurysm surgery

Background. Restoring blood flow to ischaemic tissue can causelung damage with pulmonary oedema. Hydroxyethyl starch (HES)solution, when used for volume replacement, may modify and reducethe degree of ischaemia–reperfusion injury. We comparedthe effects of HES solution with those of Gelofusine solutionon pulmonary function, microvascular permeability and neutrophilactivation in patients undergoing elective infrarenal abdominalaortic aneurysm surgery. Methods. Forty patients were randomized into two groups. Theanaesthetic technique was standardized. Lung function was assessedwith the PO₂/FI_O2 ratio, respiratory compliance, chest x-rayand a score for lung injury. Microvascular permeability wasdetermined by measuring microalbuminuria. Neutrophil activationwas determined by measurement of plasma elastase. Results. Four hours after surgery, the median (quartile values)PO₂/FI_O2 ratio was 40.3 (37.8, 53.1) kPa for the HES-treatedpatients compared with 33.9 (31.2, 40.9) kPa for the Gelofusine-treatedpatients (P<0.01, Mann–Whitney test). The respiratorycompliance was 80 (73.5, 80) ml cm^–1 H₂O inthe HES-treated patients compared with 60.1 (50.8, 73.3) mlcm^–1 H₂O in the Gelofusine-treated patients (P<0.01,Mann–Whitney test). The lung injury score 4 h after surgerywas less for the patients treated with HES compared with thepatients treated with Gelofusine (0.33 vs 0.71, P=0.01, Wilcoxonrank sum test). Mean (SD) plasma elastase was less in the HES-treatedpatients on the first postoperative day (1.96 (0.17) vs 2.08(0.24), P<0.05). The log mean microalbuminuria was less inthe HES-treated patients (0.41 vs 0.91 mg mmol^–1,P<0.05). This difference in microvascular permeability wasassociated with different volumes of colloid required to maintainstable cardiovascular measurements in the two groups of patientsstudied (3000 vs 3500 ml, P<0.01, Mann–Whitney test). Conclusion. Compared with Gelofusine, the perioperative pulmonaryfunction of patients treated with HES after abdominal aorticaneurysm surgery was better. Br J Anaesth 2004; 92: 61–6