Nine healthy volunteers were each exposed twice to a 7-h protocol consisting of 1 h breathing air, 4 h of eucapnic hypoxia (end-tidal Po₂, 50 mm Hg), and 2 h of eucapnic euoxia (end-tidal Po₂, 100 mm Hg). Volunteers received a 7-h i.v. infusion of ET-1 during one protocol (1.0–2.5 ng kg^–1 min^–1) and normal saline during the other. At intervals of 30–60 min, cardiac output and the maximum tricuspid pressure gradient during systole (P_max, an index of HPV) were measured using Doppler echocardiography, systemic arterial pressure was measured using sphygmomanometry, and plasma samples were obtained to determine ET-1 concentration.

During hypoxia, P_max increased for around 2 h before reaching a plateau. Compared with saline, ET-1 had no effect on P_max, either at baseline or during hypoxia. ET-1 infusion slightly increased diastolic arterial pressure and reduced cardiac output, but had no specific effect on the change in these variables during hypoxia. During the final 1 h of hypoxia, plasma ET-1 concentration was 1.7 (0.4) pg ml^–1 [mean (sd)] in the saline protocol and 21.9 (12.2) pg ml^–1 in the ET-1 protocol.

ET-1 infusion seems unlikely to represent a therapeutic strategy for enhancing HPV during acute (<4 h) hypoxia.

This randomized, double-blind controlled study investigated five different combining ratios of morphine and nalbuphine in 311 patients undergoing gynaecologic operations. The concentrations [morphine (mg ml^–1)]/[nalbuphine (mg ml^–1)] were 1/0 in Group 1, 0.75/0.25 (ratio 1:3) in Group 2, 0.5/0.5 (ratio 1:1) in Group 3, 0.25/0.75 (ratio 3:1) in Group 4, and 0/1 in Group 5. Patient-controlled analgesia (PCA) requirement, postoperative pain, and adverse events were evaluated throughout the postoperative 24 h period.

Twenty-four hour PCA requirements were similar among the five groups. Verbal rating scores for pain were statistically higher in Groups 2 and 4 than in Group 3. The incidences of pruritus were higher in Group 1 (15.6%) than in Group 2 (6.2%), Group 3 (3.4%), Group 4 (1.6%), and Group 5 (0%). The incidences and severity of dizziness, nausea, and vomiting were not significantly different.

The interaction between morphine and nalbuphine in PCA admixture on analgesia is additive. Combinations of morphine and nalbuphine in PCA can decrease the incidence of pruritus, and the antipruritus effect is ratio-dependent. This may provide a novel combination strategy of opioid agonist and agonist–antagonist for postoperative pain management after gynaecologic surgery.

Twenty-five patients were enrolled. Transoesophageal echocardiography was performed perioperatively before and after the correction of MR. We compared the impact of the MVR on the left ventricular FAC and the Tei index. FAC was calculated from the transgastric short-axis view and Tei index was determined from the four chambers and deep transgastric views.

Two patients were excluded because of poor acoustic windows. FAC significantly decreased after MVR from 53 (9)% to 42 (10)% (P<0.001), while Tei index was unaffected [0.46 (0.16) vs 0.47 (0.17), NS]. A significant relationship was found between the preoperative Tei index and the postoperative FAC (R=–0.64, P<0.001). Moreover, a significant and clinically relevant relationship was determined between the predicted (using preoperative Tei index) and the measured postoperative FAC (R=0.64, P<0.001).

FAC but not the Tei index is influenced by MVR. The preoperative determination of the Tei index allows predicting postoperative FAC and offers the opportunity to identify patients in whom a severe unsuspected systolic dysfunction could render difficult the weaning from cardiopulmonary bypass.

Neonates from an intensive care unit received 6-hourly prn i.v. acetaminophen dosed according to postmenstrual age (PMA): 28–32 weeks, 10 mg kg^–1; 32–36 weeks, 12.5 mg kg^–1; and ≥36 weeks, 15 mg kg^–1. A maximum of five blood samples for assay and liver function tests (LFTs) were collected. A one-compartment linear disposition model (zero-order input; first-order elimination) was used to describe time–concentration profiles using population modelling (NONMEM).

Fifty neonates, median (range) PMA 38.6 (32–45) weeks, mean (sd) weight 2.9 (0.7) kg, received a mean of 15 doses over a median 4 days with 189 serum acetaminophen and 231 LFT measurements. Standardized population parameter estimates for a term neonate were clearance (CL) 5.24 (CV 30.5%) litre h^–1 70 kg^–1 and volume of distribution (V) 76 (29.6%) litre 70 kg^–1. CL increased with PMA from 4.4 litre h^–1 70 kg^–1 at 34 weeks to 6.3 litre h^–1 70 kg^–1 at 46 weeks. The presence of unconjugated hyperbilirubinaemia was associated with reduced CL: 150 µmol litre^–1 associated with 40% CL reduction. Acetaminophen concentrations between 10 and 23 mg litre^–1 at steady state are predicted after 15 mg kg^–1 6-hourly for a neonate of PMA 40 weeks. Hepatic enzyme analysis of daily samples changed significantly for one patient whose alanine aminotransferase concentration tripled.

The parameter estimates are similar to those described for propacetamol. There was no evidence of hepatotoxicity. Unconjugated hyperbilirubinaemia impacts upon CL, dictating dose reduction.

In this controlled trial, 22 anaesthetized patients, aged 4–17 yr, undergoing strabismus surgery were randomized into two groups, Group LL and Group BSS. Patients in Group LL received topical conjunctival anaesthesia with a 1:1 mixture of lidocaine 2% and levobupivacaine 0.75%, and patients in Group BSS received balanced salt solution.

Endotracheal intubation (n=22) increased median (range) SSI from 39.2 (22.6–55.6) to 53.6 (35.8–63.3) (P<0.001), decreased PPGA from 5.62 (2.79–9.69) to 5.27 (2.59–7.54)% (P=0.001), and increased the difference of response entropy (RE) and state entropy (SE) of frontal biopotentials (RE–SE) from 3.1 (0.06–9.1) to 5.7 (0.6–9.4) (P=0.01). Conventional haemodynamic variables also increased, median (range) HR from 72.9 (56.7–113.8) to 84.2 (60.4–124.8) beats min^–1 (P<0.001), and systolic non-invasive arterial pressure (S-NIBP) from 87 (78–143) to 103 (79–125) (P=0.007). When 3 min baseline before surgery was compared with 12 min of surgery, median (range) SSI increased from 43.3 (31.2–58.0) to 49.9 (39.3–57.2) (P=0.042) vs from 46.6 (26.8–57.8) to 52.1 (31.7–60.1) (P=0.024) and PPGA decreased from 6.60 (3.10–8.24) to 5.80 (3.03–7.65)% (P<0.001) vs from 5.51 (3.25–9.84) to 5.06 (3.08–8.99)% (P=0.042), in Groups LL and BSS, respectively, but SSI or other indicators did not differ significantly between the groups.

SSI, PPGA, HR, NIBP, RE, and RE–SE detect autonomic responses to nociceptive stimuli in anaesthetized children undergoing strabismus surgery.

In this double-blind study, 120 ASA I and II patients undergoing orthopaedic surgery were included. Subarachnoid anaesthesia was performed in all patients with bupivacaine 15 mg. The patients were randomly allocated to receive saline (Group C), ketamine 0.5 mg (Group K), midazolam 75 µg kg^–1 (Group M), or ketamine 0.25 mg+midazolam 37.5 µg kg^–1 (Group KM). During surgery, a shivering score was recorded at 5 min intervals. Tympanic and axillary temperature were recorded at 10 min intervals during the perioperative period.

After 15 min, the incidences of shivering in Groups C, M, K, and KM were 60%, 50%, 23.3%, 3.3%, respectively (P=0.000). The differences between Group KM and Groups M, K, and C were statistically significant (P=0.000, P=0.026, P<0.001, respectively). The number of patients with a shivering score of ≥3 was significantly higher in Group C compared with Groups M, K, and KM (8 vs 4, 1, and 0, respectively, P=0.040).

Prophylactic use of ketamine 0.25 mg kg^–1+midazolam 37.5 µg kg^–1 i.v. was more effective than ketamine 0.5 mg kg^–1 i.v. or midazolam 75 µg kg^–1 i.v. in preventing shivering developed during regional anaesthesia.

One hundred and fifty-four adult patients admitted to the recovery room during regular working hours were included. A screening assessment for delirium was performed in the recovery room by a trained research team at the time when the patient was judged to be ‘ready for discharge’. Delirium monitoring was performed with the Confusion Assessment Method (CAM), the Delirium Detection Score (DDS), and the Nursing Delirium Screening Scale (Nu-DESC). The Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV criteria were used as the gold standard.

Delirium in the recovery room was seen in 21 patients (14%) with the DSM-IV criteria, in 11 patients (7%) with the CAM, in four patients (3%) with the DDS, and in 37 patients (24%) with the Nu-DESC. Sensitivity and specificity were 0.43 and 0.98 for the CAM, 0.14 and 0.99 for the DDS, and 0.95 and 0.87 for the Nu-DESC, respectively.

All scores used were very specific, but the CAM and the DDS were less sensitive compared with the gold standard. Overall, the Nu-DESC was the most sensitive test in the recovery room to detect delirium.

Loss of consciousness (LOC) was repetitively induced by bolus injections of propofol in 24 patients undergoing elective surgery in spinal anaesthesia. SSEP and the BIS were recorded during LOC and recovery of consciousness (ROC). The level of consciousness was clinically assessed by the observer’s assessment of alertness/sedation scale. Propofol venous plasma concentrations were measured simultaneously.

At LOC, all SSEPs latency components were prolonged (P<0.001), whereas amplitudes of the components ≥45 ms were smaller (P=0.008) and the BIS values were lower (P<0.001). None of the EEG variables regained baseline levels during ROC. Regression analyses revealed that the SSEP components (five latencies and five amplitudes) explained 33% of the variance when predicting ROC; the BIS explained 12%. The combination of SSEP and BIS explained 37% of variance in this patient sample. Propofol venous plasma concentration was 1.2 (0.8) µg ml^–1 during LOC and 0.4 (0.5) µg ml^–1 during ROC.

The present results indicate the usefulness of combining variables of the evoked and spontaneous EEG to measure different levels of consciousness, because the SSEP provide additional information beyond the BIS. Inter-individual variability of all the EEG variables limits their predictive potency of ROC after propofol infusion.

Primary cultures of rat cortical neurones were exposed in concentration– and time–response experiments to 0.02, 0.2, 2, and 20 µM propofol or lipid vehicle. Neurones were pretreated with the GABA_A receptor (GABA_AR) antagonist, bicuculline, the myosin II ATPase activity inhibitor, blebbistatin, and the F-actin stabilizing agent, phalloidin, followed by administration of propofol (20 µM). Changes in neurite retraction were evaluated using time-lapse light microscopy.

Propofol caused a concentration- and time-dependent reversible retraction of cultured cortical neurone neurites. Bicuculline, blebbistatin, and phalloidin completely inhibited propofol-induced neurite retraction. Images of retracted neurites were characterized by a retraction bulb and a thin trailing membrane remnant.

Cultured cortical rat neurones retract their neurites after exposure to propofol in a concentration- and time-dependent manner. This retraction is GABA_AR mediated, reversible, and dependent on actin and myosin II. Furthermore, the concentrations and times to full retraction and recovery correspond to those observed during propofol anaesthesia.

Records of 30 patients with laryngotracheal stenosis, but not with a tracheostomy, undergoing lumen-restoring surgery were prospectively reviewed. Awake spirometry and flow-volume loops were recorded before the procedure. Patients received i.v. anaesthesia induction, muscle paralysis, and positive-pressure ventilation through a laryngeal mask airway (LMA). Anaesthetized tidal volume (TV) and flow-volume loop measurements were obtained.

We studied 19 males and 11 females [mean age 47 (sd 19) yr], ASA Grade III or IV, with lesions at 31 (10) mm below the vocal cords. Peak inspiratory flow (PIF) and peak expiratory flow (PEF) rates were 2.0 (1.2) litre s^–1 and 3.2 (1.7) litre s^–1 when awake. Tidal volumes were 657 (193) ml [9.2 (3.6) ml kg^–1] and 586 (158) ml [8.3 (3.1) ml kg^–1], respectively, when anaesthetized. There was a significant reduction in the PEF/PIF ratio, from a mean of 2.4 (1.3) awake to 1.0 (0.1) when anaesthetized (P<0.0001). A significant correlation was noted between awake PEF and anaesthetized expiratory TV (r=0.57; P<0.001) but not between awake PIF and anaesthetized inspiratory TV.

Positive-pressure ventilation through an LMA is an effective method of ventilating patients with laryngotracheal stenosis. Spontaneous ventilation creates negative inspiratory intratracheal pressure that exacerbates an extrathoracic lesion, whereas positive-pressure ventilation generates positive intratracheal pressure that improves ventilation. This helps explain the apparent resolution of airway obstruction after positive-pressure ventilation.

Sixty patients undergoing arthroscopic knee surgery were randomly assigned into three groups in a double-blind placebo controlled study. The control group received i.v. and intra-articular saline, the intra-articular group received i.v. saline and intra-articular dexmedetomidine, and the i.v. group received i.v. dexmedetomidine and intra-articular saline. Haemodynamic changes, pain visual analogue scale (VAS), sedation score, the time to first postoperative analgesic request, and the total postoperative analgesic use during the first 24 h were evaluated.

Dexmedetomidine administration resulted in a significant reduction in pain scores for 6 h after operation in the intra-articular group but only for 1 h in the i.v. group. The time to first postoperative analgesic request was longer in the intra-articular group [312.0 (sd 120.7) min] compared with the control group [71.0 (50.1) min] and the i.v. group [102.1 (54.4) min] (P<0.001). Total diclofenac requirement was significantly lower in the intra-articular group [90.0 (46.2) mg] than in the control group [165.0 (52.2) mg] and in the i.v. group [129.3 (54.3) mg] (P<0.05).

Intra-articular dexmedetomidine enhanced postoperative analgesia after arthroscopic knee surgery, with an increased time to first analgesic request and a decreased need for postoperative analgesia.

We present the static and dynamic validation of a novel computational model of gas exchange in acute respiratory distress syndrome (ARDS) based upon the Nottingham Physiology Simulator. Arterial gas tension predictions were compared with data derived from ARDS patients. The subsequent study examined the indices' susceptibility to variation induced by independent changes in Fi_o2 (0.3–1.0), haemoglobin concentration (Hb: 6–14 g dl^–1), oxygen consumption (Vo₂: 250–350 ml min^–1), and Pa_co2 (4–8 kPa).

Static validation produced a mean error of –0.3%, a 10-fold improvement over previous models. Dynamic validation produced a mean prediction error of –0.05 kPa for Pa_o2 and 0.09 kPa for Pa_co2. Every parameter, especially Fi_o2, induced variation in all indices. The least Fi_o2-dependent index was Qs/Qt (variation: 5.1%). In contrast, Pa_o2/Fi_o2 varied by 77% through the range of Fi_o2.

We have improved simulation of gas exchange in ARDS by using a sophisticated respiratory model. Using the validated model, we have demonstrated that the current indices of oxygenation vary with alteration in Hb, Pa_co2, and Vo₂ in addition to their previously well-documented dependence on Fi_o2.

A total of 160 ASA I–III children were randomly assigned to receive lct–propofol or mct/lct–propofol, 5 mg kg^–1, with lidocaine 10 mg ml^–1 or saline. The site and size of venous cannulation and restlessness before injection were recorded in each patient. A pain score graded 0–6 was established based on spontaneous verbal and motor reaction during injection, each graded 0–3. Kruskall–Wallis and Mann–Whitney tests were used for statistical analysis.

Median pain scores decreased in all groups compared with lct–propofol–saline (P<0.001) and were least in the lct/mct–propofol–lidocaine group (P<0.001). Painless injection (score, 0–2) occurred in 92.5% of patients in the mct/lct–propofol–lidocaine group compared with 41–77% in the others (P<0.001).

Mct/lct–propofol caused significantly less pain than lct–propofol in preschool children. Mixing of lidocaine with mct/lct–propofol resulted in a further significant decrease, virtually eliminating the pain on injection.

Clot formation was measured by thromboelastography (TEG) using blood from healthy volunteers. In vitro effects of rFVIIa with haemodilution, acidosis, and hypothermia were examined. Conditions were induced by dilution with NaCl (0.9%), lactated Ringer's solution, albumin 5%, or hydroxyethyl starch (HES) solutions [MW (molecular weight) 130–670 kDa]; by adjusting pH to 6.8 with 1 M HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulphonic acid) buffer; or by reducing temperature to 32°C. We also studied the effect of low vs high MW HES (MW 200 vs 600 kDa) and rFVIIa on in vivo bleeding time (BT) in rabbits.

Haemodilution progressively altered TEG parameters. rFVIIa improved TEG parameters in the presence of acidosis, hypothermia or 20% haemodilution (P<0.05). At 40% haemodilution, the rFVIIa effect was diminished particularly with high MW HES. In vivo, rFVIIa shortened the BT (P<0.05) with low but not high MW HES.

Efficacy of rFVIIa was affected by the degree of haemodilution and type of volume expander, but not by acidosis or hypothermia.

A prospective, randomized, cross-over study of LMA-Proseal^TM (PLMA) and SLMA in 36 fasted, adult, female patients with general anaesthesia, neuromuscular block (NMB) and positive pressure ventilation (PPV) is presented.

First attempt insertion in 35/36 patients in each group (two attempts in one PLMA and three in one SLMA patient) with successful PPV in all. Median insertion time (15 s) and glottic seal pressure (28 cm H₂O) were similar in both groups. Median volume of air for cuff inflation to 60 cm H₂O was 22.4 ml (PLMA) and 21.9 ml (SLMA). Median age and BMI: 50 yr (range 25–74), 51 yr (23–72) and 29 kg m^–2 (range 21–46), 30 kg m^–2 (20–42) in PLMA and SLMA groups, respectively. Mallampati score mean arterial pressures after induction, and 1 min after induction and insertion of the first device were similar. A lubricated gastric tube (16Fr) was passed at the first attempt in both devices: median gastric content 15 ml (5–75), 17.5 (5–124) and a median pH of 3 (1–6), 1.5 (1–6) in the PLMA and SLMA groups, respectively. Fibreoptic laryngoscopic scores of 1–2 were recorded in 29/36 in both groups.

Insertion success, glottic seal pressure and gastric access were similar in SLMA and PLMA.

Regional ventilation was studied by EIT in 40 patients requiring insertion of left-sided DLTs for OLV during thoracic surgery. EIT was recorded during two-lung ventilation before induction of anaesthesia and after DLT placement, and during OLV in the supine and subsequently in the lateral position. EIT measurements were made before and after verification of correct DLT placement by fibreoptic bronchoscopy (FOB).

EIT accurately displayed distribution of ventilation between left and right lung online. All cases (n=5) of initially misplaced DLTs in the contralateral right main bronchus were detected by EIT. However, EIT did not allow prediction of FOB-detected endobronchial cuff misplacement requiring DLT repositioning. Furthermore, after DLT repositioning, distribution of ventilation, as assessed by EIT, did not change significantly (all P>0.5).

This study demonstrates that EIT enables accurate display of left and right lung ventilation and, thus, non-invasive online recognition of misplacement of left-sided DLTs in the contralateral main bronchus. However, as distribution of ventilation did not correlate with endobronchial cuff placement, EIT cannot replace FOB in the routine control of DLT position.

Fifty-one adult male rats were anaesthetized with isoflurane, tracheostomized, and a femoral artery and vein were cannulated. First, we compared the efficacy of sugammadex 15 mg kg^–1 and neostigmine 0.06 mg kg^–1 to reverse respiratory effects of rocuronium-induced partial paralysis [train-of-four ratio (T4/T1)=0.5]. Subsequently, we compared the safety of sugammadex and neostigmine given after recovery of the T4/T1 to 1, by measuring phasic genioglossus activity and breathing.

During partial paralysis (T4/T1=0.5), time to recovery of minute volume to baseline values was 10.9 (2), 75.8 (18), and 153 (54) s with sugammadex, neostigmine, and placebo, respectively (sugammadex was significantly faster than neostigmine and placebo, P<0.05). Recovery of T4/T1 was also faster for sugammadex than neostigmine and placebo. Neostigmine administration after complete recovery of T4/T1 decreased upper airway dilator muscle activity to 64 (30)% of baseline and decreased tidal volume (P<0.05 for both variables), whereas sugammadex had no effect on either variable.

In contrast to neostigmine, which significantly impairs upper airway dilator muscle activity when given after recovery from neuromuscular block, a reversal dose of sugammadex given under the same conditions does not affect genioglossus muscle activity and normal breathing. Human studies will be required to evaluate the clinical relevance of our findings.

We conducted a national postal survey of the policies and protocols used by acute pain services for investigating clinical signs suggestive of epidural haematoma, and the availability of urgent MRI scans. This was a repeat of a survey that was carried out in 2001, but not published.

The response rate was 84%. Of the acute pain services that responded, 99% have a written protocol for running epidural infusions, 91% include regular assessment of sensory and motor function, and 55% have a written protocol for the investigation of abnormal motor block. On-site 24 h access to MRI scanning facilities was available to 57%, 33% have arrangements with another hospital, and 10% do not have 24 h access to MRI. Thirty per cent of respondents knew of an epidural haematoma related to epidural analgesia in their hospital, one-third of which were not diagnosed and treated within 24 h.

Improvements in monitoring have occurred over the last 5 yr, but observations of neurological function are not routine in all units, and are not continued after removal of the epidural catheter in the majority. The authors suggest that acute pain services should be responsible for protocols for the investigation and treatment of epidural haematomas.

We carried out non-participant practice observation and in-depth interviews with practitioners working in the recovery room of an English hospital and used qualitative methods to analyse the resulting transcripts.

We observed 45 handovers taking place between 17 anaesthetists and 15 nurses in the recovery room of the operating theatre suite. These took place in an environment that is event-driven, time-pressured, and prone to concurrent distractions. Anaesthetists and nurses often had differing expectations of the content and timing of information transfer. The point at which transfer of responsibility for the patient occurred during the handover process was variable and depended not only on the condition of the patient but also on the professional relationship between the nurse and doctor concerned. Handover also provided an ‘audit point’ in care where the patient’s intraoperative progress was reviewed and plans were made for further management. Here, as in the transfer of responsibility, we found evidence that nurses play a greater role in defining the limits of anaesthetists’ practice than might be expected.

Patient handovers in the recovery room are largely informal, but nevertheless show many inherent tensions, both professional and organizational. Although formalized handover procedures are often advocated for the promotion of safety, we suggest that they are likely to work best when the informal elements, and the cultural factors underlying them, are acknowledged.

We studied 1000 patients [mean (range) age, 69 (22–95) yr; males 810] who underwent acute or elective abdominal or thoracoabdominal aortic aneurysm surgery between January 1999 and April 2007, at Semmelweis Medical University (Budapest, Hungary). Patients were evaluated for clinical risk factors, chronic medication use, and surgical characteristics. Propensity score analysis was used to adjust for the potential bias in dihydropiridine calcium-channel blocker use. Multivariable logistic regression analyses were applied to study the association between the likelihood of dihydropiridine calcium-channel blocker use and mortality occurring within 30 days of surgery.

Perioperative mortality occurred in 85 (8.5%) patients. Thirty-day mortality was significantly higher in dihydropiridine calcium-channel blocker users compared with non-users, 14.0% vs 6.0%; crude odds ratio (OR) 2.6, 95% confidence interval (CI): 1.6–4.0, P<0.0001. Even after correcting for other baseline covariates and propensity for these agents dihydropiridine calcium-channel blocker use was associated with increased 30-day mortality, OR (95% CI) 2.5(1.3–4.6), P=0.003.

Dihydropiridine calcium-channel blocker use in patients with acute or elective aortic aneurysm surgery is independently associated with an increased incidence of perioperative mortality.

The feasibility of lung isolation and one-lung ventilation (OLV) in human cadavers is examined, along with displacement of the bronchus blocker during head and neck movement.

Cadaveric endotracheal intubation with the Papworth BiVent tube was straightforward and comparable with intubation with a conventional single-lumen tube (SLT). Reliable lung isolation was achieved considerably faster using the Papworth BiVent tube than with a bronchoscopically guided bronchial blocker through an SLT (mean 7.75 s BiVent tube vs 128.2 s SLT). The Papworth BiVent tube also prevented displacement of the blocker from its position in the bronchus on head movement.

This study in human cadavers has shown that it is feasible to use the Papworth BiVent tube to attain rapid and secure lung isolation for OLV. Further work is required in clinical settings.

Twenty healthy male volunteers were studied. Forearm blood flow-flux was measured using laser Doppler flowmetry, and the magnitude of the hyperaemic response to brachial artery occlusion for 20 s was recorded. Control cream, EMLA^®, or Ametop^® were applied and covered with an occlusive dressing for 60 min. Blood flow-flux and the hyperaemic response measurements were then repeated, with the laser Doppler probes sited over the areas of skin to which the local anaesthetic creams had been applied. Measurements were made at 60, 90, and 120 min after the application of the creams. The THR ratio (THRR) was calculated at each time point, defined as the net hyperaemic flow-flux divided by the baseline flow-flux.

At 60 min, Ametop caused a significantly greater increase in blood flow and decrease in THRR over control than EMLA [net increase of mean blood flow (sd) over control 95 (61) vs 2 (17) AU (P<0.001), net mean THRR decrease over control 1.33 (1.85) vs –0.34 (1.33) (P<0.02)].

The application of topical Ametop decreases microvascular tone and vasoreactivity of the forearm skin in healthy volunteers.