Supravalvular aortic stenosis is associated with the Williams–Beuren syndrome, but it also occurs in a non-syndromatic congenital form. An elastin gene mutation of chromosome 7q11.23 is responsible in both cases. The vascular features are identical. These patients have a higher risk of sudden death, particularly when undergoing diagnostic or surgical procedures. We report the account of a family with a new mutation in the elastin gene. Screening over three generations revealed eight affected individuals. The cardiac and vascular malformations ranged from mild asymptomatic supravalvular aortic stenosis and isolated dysplastic atrioventricular valves to diffuse arterial hypoplasia. Two infants presented arteries affected at multiple locations, including the left coronary artery. Both died of sudden cardiac death and myocardial ischaemia, one while under general anaesthesia for cardiac catheterisation, and the other perioperatively. We discuss the pathophysiological aspects in these patients that deserve consideration before any general anaesthesia is administered.

We aimed to investigate whether auditory brainstem response (ABR), assessed immediately after grommet insertion, was an accurate measure of hearing threshold.

Ten children were recruited (20 ears). Patients underwent transient evoked otoacoustic emission (TEOAE) and ABR tests before and after grommet insertion under general anaesthetic. A third assessment was conducted at a six-week review, without anaesthetic or sedation. The hearing threshold in dB and the presence of TEOAE were recorded by senior audiologists. The results of each investigation were compared. At review, only 15 ABR and 17 TEOAE tests, of a possible 20, were recorded.

Transient evoked otoacoustic emissions were recorded in 30 per cent of ears pre-operatively, 20 per cent of ears post-operatively and 82 per cent of ears at six-week review. The average ABR thresholds were 23.75 dB (range 10–45 dB) pre-operatively, 27.25 (range 15–40 dB) post-operatively and 15 dB (range 5–25 dB) at six-week review. Comparing pre- and post-operative assessment, decreased thresholds were seen in six ears and elevated thresholds in 11. Comparing the six-week review ABR with the post-operative ABR, 13 ears had decreased thresholds, by as much as 20 dB. Thresholds of 35 dB or greater were measured in six ears immediately after grommet insertion (maximum 40 dB). Threshold shifts of 15 dB or greater was observed in seven ears. The intra-subject variation was shown to be significant (p<0.001) when repeated measures analysis of variance was applied.

We conclude that there is evidence that ABR can be inaccurate after grommet insertion, overestimating hearing thresholds. We believe that the mechanism by which the error is realised is temporary threshold shift.

Summary

Background and objective: An alteration in production of both interleukin-10 (IL-10) and nitric oxide (NO) has been found following surgical/anaesthesia trauma. It is also suggested that IL-10 could be an important factor in regulating NO metabolism during the postoperative period. Furthermore, NO seems to play a crucial role in the anaesthetic state. The purpose of this study was to investigate plasma levels of IL-10 and NO following surgery, any possible correlation between these two variables and whether anaesthesia technique could influence NO and IL-10 circulating concentrations.

Methods: Thirty-two patients scheduled to undergo elective major surgery were enrolled in the study and allocated into two groups to receive two different techniques of anaesthesia, total intravenous (i.v.) anaesthesia (Group I) and inhalational anaesthesia (Group II). Blood samples were drawn before (t0), at the end (t1) of operation and after 24 h (t2). Plasma IL-10 and NO levels were measured by using an enzyme-linked-immunosorbent assay (ELISA) and a total NO assay kit, respectively.

Results: In both patient groups there was a significant decrease of plasma NO levels at the end of surgery (30.35 ± 2.70 mmol L−1 at t0 to 13.76 ± 1.51 mmol L−1 at t1 in Group I, P < 0.0001; 28.23 ± 2.50 mmol L−1 at t0 to 11.38 ± 0.95 mmol L−1 at t1 in Group II, P < 0.0001). This reduction remained at 24 h postoperatively (14.33 ± 1.52 mmol L−1 in Group I, P < 0.0001; 12.52 ± 1.11 mmol L−1 in Group II, P < 0.0001, both vs. t0). There was an increase in IL-10 concentrations (26.35 ± 3.42 pg mL−1 and 75.39 ± 8.33 pg mL−1 at t1 and t2, respectively, vs. 4.93 ± 0.31 pg mL−1 at t0, P = 0.03 and P < 0.0001, respectively, in Group I; 26.18 ± 3.22 pg mL−1 and 69.91 ± 7.33 pg mL−1 at t1 and t2, respectively, vs. 5.50 ± 0.33 pg mL−1 at t0, P = 0.02 and P < 0.0001, respectively, in Group II). No relationship was found between circulating IL-10 and NO.

Conclusions: During the postoperative period, IL-10 overproduction does not correlate with the decrease in systemic NO concentration.

Summary

Background and objective: The exact change in circulating blood volume (BV) during general anaesthesia is still unknown because there is no standard method of evaluating BV. We evaluated the changes in BV by general anaesthesia using simple and easy estimation methods.

Methods: Fourteen patients scheduled for minor surgery under general anaesthesia were enrolled. Propofol and vecuronium bromide were used for the induction of anaesthesia, and anaesthesia was maintained with sevoflurane and nitrous oxide. Haematocrit (Hct), total protein concentration (TP), as well as colloid osmotic pressure (COP) measured using a colloid osmometer, were determined before anaesthesia, and 30, 60 and 90 min after the induction of general anaesthesia. BV was calculated using Allen's formula and the changes in Hct, TP and COP. The estimated BV was compared with directly measured BV using indocyanine green dilution method (BVICG).

Results: Hct, TP and COP significantly decreased after the induction of anaesthesia (Hct: 42.1–39.4%; TP: 7.3–6.9 g dL−1; COP: 23–19 mmHg). The calculated BV as well as BVICG significantly increased after induction of anaesthesia (calculated by COP: 4.13–5.03 L; BVICG: 4.54–5.56 L). The change rate in BV calculated by the change of COP was larger than other calculated BVs, and was approximated to the change rate in BVICG. After emergence from anaesthesia, all values tended to return to baseline.

Conclusions: General anaesthesia increases BV. The value of BV calculated from the change in COP was most changeable.

Summary

Background and objective: One of the complications of laparoscopic surgery is carbon monoxide production during electrocautery. The aim of our study was to ascertain the relationship between intraperitoneal and alveolar concentrations of carbon monoxide and systemic carboxyhaemoglobin in patients undergoing laparoscopic cholecystectomy and anaesthetized with a closed system, where the carbon monoxide excreted through the lungs is accumulated in the circuit and thus re-inhaled.

Methods: Nine consecutive patients undergoing laparoscopic cholecystectomy were studied. Patients' lungs were ventilated with a closed anaesthesia breathing system (Physioflex®). Measurements were taken after establishing pneumoperitoneum (baseline) and at 5, 15 and 30 min after starting electrocautery.

Results: Mean duration of pneumoperitoneum was 42 ± 13 min with cumulative electrocautery time of 2.4 ± 1.8 min. Intraperitoneal carbon monoxide concentrations increased significantly at 5, 15 and 30 min reaching peak values of 481 ± 151 ppm at 15 min. No significant differences were found in alveolar carbon monoxide and carboxyhaemoglobin concentrations with respect to baseline.

Conclusions: No significant increase in carboxyhaemoglobin is produced during laparoscopic surgery, even under closed-system anaesthesia without pulmonary carbon monoxide elimination. This is most likely due to a low peritoneal absorption of carbon monoxide. We conclude that in adult patients, no carbon monoxide intoxication is caused if reasonable periods of electrocautery are used and the intraperitoneal gas is regularly renewed.

We prospectively evaluated the effects of pneumoperitoneum and reverse Trendelenburg position on cardiopulmonary function in 20 ASA physical status II–III morbidly obese patients (body mass index > 35 kg m−2) undergoing laparoscopic gastric banding. After general anaesthesia was induced, patients' lungs were ventilated using intermittent positive pressure ventilation (at measurement times, the following parameters were used: tidal volume 12 mL kg−1 ideal body weight, respiratory rate of 12 bpm, an inspiratory to expiratory time ratio of 1 : 2). Haemodynamic variables, blood gas parameters, and lung/chest compliance were recorded: in the supine position, after induction of general anaesthesia (T0, baseline) and induction of pneumoperitoneum (T1); after placing the patient in a 25° reverse Trendelenburg position (T2); during the surgical time (T3); before deflating the abdomen (T4); after pneumoperitoneum resolution (T5), and before the end of anaesthesia, with the patient supine (T6). The PaO2, PaO2/FiO2 ratio, and lung/chest compliance decreased during the study. After the pneumoperitoneum had been resolved, lung/chest compliance but not oxygenation parameters returned to baseline values. The arterial to end-tidal CO2 tension difference progressively increased from 0.38 ± 0.3 kPa (2.85 ± 2.25 mmHg) (T0) to 0.63 ± 0.3 kPa (4.73 ± 2.25 mmHg) (T6). In morbidly obese patients, undergoing laparoscopic gastric banding, a CO2 pneumoperitoneum markedly affected gas exchange and lung/chest compliance, while positioning the patient in a 25° reverse Trendelenburg position had no beneficial effects.

To compare ease of maintenance and recovery characteristics of sevoflurane and propofol plus fentanyl in day-care anaesthesia, 60 outpatients undergoing elective surgery of up to 3 h duration were randomized to receive sevoflurane or propofol as their primary anaesthetic. Induction was always carried out with propofol, but a fentanyl bolus 5 μg kg−1 was added in the propofol group. Anaesthesia was supplemented with up to 70% N2O. Significantly shorter times to extubation (10.03 min ± 3.2 SD vs. 17.2 ± 7.3; P<0.001) and emergence (10.4 ± 3.1 vs. 16.8 ± 6.4; P<0.001) were observed in the sevoflurane group. Patients treated with sevoflurane felt less confused, showed better performances in the digit symbol substitution test and achieved higher modified Aldrete scores sooner in the post-operative course. Maintenance of anaesthesia with sevoflurane produces faster emergence and recovery than propofol plus fentanyl after anaesthesia of short to intermediate duration.

A case of recurarization in the recovery room is reported. Accumulation of atracurium in the intravenous line led to recurarization after flushing the line in the recovery room. A respiratory arrest with severe desaturation and bradycardia occurred. Circumstances leading to this event and the mechanisms enabling a neuromuscular blockade to occur, following the administration of a small dose of relaxant, are discussed.

The cuffed oropharyngeal airway (COPA) was compared with the laryngeal mask airway (LMA) with respect to airway quality and respiratory adverse events in 140 spontaneously breathing patients undergoing procedures of duration more than 1 h. Patients were allocated randomly to receive either a COPA (n=72) or a LMA (n=68) for airway management during anaesthesia induced with propofol and maintained with sevoflurane, nitrous oxide and oxygen. Groups were similar when comparing the first-time successful insertion rates (COPA: 94.5%, LMA: 95.6%), but airway manipulations (head tilt, chin lift, jaw thrust) were reported more frequently in the COPA group, 27.8% vs. LMA, 4.4%; P=0.0005. During the post-induction apnoeic period, all patients were ventilated manually and although, mean (SD) leak pressure was lower in the COPA group (18 (4) cm H2O vs. LMA, 22 (3) cm H2O; P< 0.0001), the tidal volumes achieved did not differ in both groups: COPA, 9.5 (4) mL kg−1 vs. LMA, 10.5 (4.5) mL kg−1. The incidences of intra-operative coughing, gagging, laryngospasm, oxygen desaturation and hypercarbia were similar in both groups. Although both devices are equivalent with respect to the overall respiratory problems during spontaneous breathing anaesthesia of intermediate or prolonged duration, the LMA was associated with fewer airway quality problems, suggesting that it is more efficacious in securing the airway.