Summary

Sepsis is associated with a profound intravascular fluid deficit due to vasodilatation, venous pooling and capillary leakage. Fluid therapy is aimed at restoration of intravascular volume status, haemodynamic stability and organ perfusion. Circulatory stability following fluid resuscitation is usually achieved in the septic patient at the expense of tissue oedema formation that may significantly influence vital organ function. The type of fluid therapy, crystalloid or colloid, in sepsis with capillary leakage remains an area of intensive and controversial discussion. The current understanding of the physiology of increased microvascular permeability in health and sepsis is incomplete. Furthermore, there is a lack of appropriate clinical study end-points for fluid resuscitation. This review considers critically the clinical and experimental data analysing the assessment of capillary leakage in sepsis and investigating the effects of different fluid types on increased microvascular permeability in sepsis.

Summary

Background and objective: A variable incidence rate of renal dysfunction (3–35%) after cardiac surgery with cardiopulmonary bypass has been reported. The aim was to define the typical pattern of renal dysfunction that follows coronary surgery with cardiopulmonary bypass using albumin, immunoglobulin (IgG), α1-microglobulin and β-glucosaminidase (β-NAG) excretion as indicators.

Methods: Twenty patients with preoperative normal renal function, defined by plasma creatinine, creatinine clearance, fractional excretion of sodium and renal excretion of proteins, undergoing elective myocardial revascularization surgery with cardiopulmonary bypass, were prospectively studied. Variables recorded were demographic and haemodynamic variables, duration of cardiopulmonary bypass and aortic clamping, intra- and postoperative urine output, plasma creatinine concentration, creatinine clearance and excretion of sodium, albumin, IgG, β-glucosaminidase (β-NAG), and β-microglobulin. Measurements were made preoperatively, immediately before and then during and immediately after cardiopulmonary bypass, and again at 1, 24, 72 h, 7 and 40 days following surgery.

Results: Albumin and IgG excretion rose significantly during cardiopulmonary bypass (P < 0.05), remaining at these levels at 24 h postoperatively. An increase of α1-microglobulin and β-NAG concentrations was observed during cardiopulmonary bypass (P < 0.05), which were maintained until the seventh postoperative day and remained elevated in some patients at the 40th postoperative day. This correlated with preoperative diabetes mellitus (P < 0.001), low cardiac output after cardiopulmonary bypass (P < 0.001) and the duration of stay in the intensive care unit (P < 0.001).

Conclusions: The pattern of renal dysfunction after cardiopulmonary bypass for myocardial revascularization is characterized by temporary renal dysfunction at both glomerular and tubular levels with an onset within 24 h of surgery and which lasts between 24 h and 40 days, respectively, following surgery.

Summary

Background and objective: Monitoring the depth of anaesthesia by the bispectral index facilitates the titration of anaesthetic drugs during operation as well as assisting in early recovery. We planned to use this index to control the administration of anaesthetic agents in order to stabilize haemodynamics and promote recovery from anaesthesia in patients undergoing cardiac surgery with cardiopulmonary bypass.

Methods: Thirty adult patients undergoing valve replacement or coronary artery grafting under cardiopulmonary bypass were studied in a prospective, randomized, controlled study. Bispectral index monitoring was used in all patients. Patients received isoflurane anaesthesia and boluses of morphine: in the study group, anaesthetic depth was controlled using the bispectral index and clinical variables. In the control group, the bispectral index monitor could not be viewed by the anaesthesiologist. Bispectral index, mean arterial pressure and heart rate were noted every 5 min, and the incidence of hypotension, hypertension, tachycardia and bradycardia also noted. The time to recovery, when patients started obeying commands, was also recorded.

Results: Patients in the study group had significantly less hypertension and tachycardia (P < 0.05) than those in the control group. The time to recovery of consciousness was less in the study group than in the control group (n.s., P > 0.05). The bispectral index rose significantly in the control group at the time of institution and termination of cardiopulmonary bypass (P < 0.05).

Conclusions: Anaesthesia controlled by bispectral index monitoring decreases the incidence of haemodynamic disturbances and facilitates titration of anaesthetic agents during cardiopulmonary bypass and thus may assist recovery from anaesthesia.

Summary

Background and objective: In clinical trials, autoregulation and carbon dioxide reactivity are preserved during propofol anaesthesia. Paradoxical increases of blood flow velocity during induction of anaesthesia could be demonstrated in patients with brain tumours. This study evaluates the effects of propofol on cerebral blood flow velocity in patients undergoing surgery for brain tumours and vascular malformations.

Methods: Changes in cerebral blood flow velocity after the administration of propofol were assessed using bilateral 2 MHz transcranial Doppler probes in 47 patients undergoing surgery for brain tumours and in 22 patients undergoing surgery for aneurysms and angiomas.

Results: Flow reduction after propofol was slightly less pronounced on the side of the tumour; in patients with cerebrovascular lesions, no difference between the two sides was detectable. After the administration of propofol a flow increase was present on the side of the tumour in 2 patients. In 3 patients with angiomas, the flow decrease after the administration of propofol was less pronounced on the side of the angioma. Neither observation gave statistical proof of abnormality.

Conclusions: The flow changes after propofol may give a hint of cerebrovascular reactivity. Further investigations should focus on combined measurements of cerebral autoregulation and carbon dioxide reactivity and should focus on patients with impaired consciousness to test for reliability.

Summary

Background and objective: We conducted an open, prospective, randomized study to compare the efficacy, safety and recovery characteristics of remifentanil or propofol during monitored anaesthesia care in patients undergoing colonoscopy.

Methods: Forty patients were randomly assigned to receive either propofol (1 mg kg−1 followed by 10 mg kg−1 h−1, n = 20) or remifentanil (0.5 μg kg−1 followed by 0.2 μg kg−1 min−1, n = 20). The infusion rate was subsequently adapted to clinical needs.

Results: In the propofol group, arterial pressure and heart rate decreased significantly from the baseline. These variables remained unchanged in the remifentanil group, but hypoventilation occurred in 55% of patients. Early recovery was delayed in the propofol group (P < 0.002). Recovery of cognitive and psychomotor functions was faster in the remifentanil group. Fifteen minutes after anaesthesia, the Digit Symbol Substitution Test score was 28.6 ± 12.8 versus 36.2 ± 9.4 and the Trieger Dot Test score was 25.6 ± 8.1 versus 18.7 ± 4.1 in the propofol and remifentanil groups, respectively (both P < 0.05). Patient satisfaction, using a visual analogue scale, was higher in the propofol group (96 ± 7 versus 77 ± 21, P < 0.001).

Conclusions: Remifentanil proved efficient in reducing pain during colonoscopy. Emergence times were shorter and the recovery of cognitive function was faster with remifentanil compared with propofol. Remifentanil provided a smoother haemodynamic profile than propofol; however, the frequent occurrence of remifentanil-induced hypoventilation requires the cautious administration of this agent.

Summary

Background and objective: The Datex-Ohmeda neuromuscular transmission module (M-NMT)® is a new monitor that is part of the AS/3® anaesthesia monitor. It incorporates a mechanosensor, which is a piezoelectric polymer attached to the hand. The module was compared with a force transducer in 30 patients requiring neuromuscular blockade.

Methods: Anaesthesia was induced with fentanyl and propofol, and tracheal intubation was performed without muscle relaxants. Neuromuscular blockade was assessed by the test module on one arm and the force transducer on the other arm. When the response to train-of-four stimulation had been stable in both arms for 3 min, rocuronium 0.2 mg kg−1 was injected intravenously. During recovery from blockade, the train-of-four ratio was measured in 15 patients, and the ratio of response to double-burst stimulation in the other 15 patients. Data analysis was by difference plots.

Results: Both devices had acceptable coefficients of repeatability. The M-NMT® module was biased by +1.3% (upper limit of agreement 14.2%, lower limit −12.9%) for the recovery of the train-of-four ratio, and by +1.09% (17%, −16%) for the recovery of double-burst stimulation ratio.

Conclusions: The Datex-Ohmeda M-NMT® gives measurements that are repeatable and gives good enough correspondence with a force transducer that it can be used clinically to assess recovery of neuromuscular blockade, but the limits of agreement rule out research applications.

Summary

Background and objective: When the endotracheal tube cuff is repeatedly aspirated to avoid excessive cuff pressure during nitrous oxide anaesthesia, a stable cuff pressure is eventually achieved. We assessed the time required to achieve a stable cuff pressure after repeated cuff deflation.

Methods: During 67% nitrous oxide and oxygen anaesthesia, air-filled cuffs of a standard tracheal tube (Mallinckrodt Hi-Contour®) were repeatedly deflated every 30 min for the first 3 or 4 h to inhibit excessive pressure (Groups Def-3 or Def-4, respectively, n = 10 for each); the cuff pressure was monitored for an additional 3 h. In some patients, the study was terminated at 1, 2, 3 and 4 h (n = 6 for each).

Results: Cuff pressure in Group Def-3, but not in Group Def-4, >22 mmHg after stopping cuff aspiration. Intracuff nitrous oxide concentrations increased during repeated cuff deflation and increased further in Group Def-3 during an additional 3 h (from 39.8 ± 4.7% to 44.3 ± 3.8%; P < 0.05), whereas intracuff nitrous oxide concentrations at 4 h were not different from those in Group Def-4 at the end of the study (43.7 ± 4.5% versus 42.3 ± 4.8%; P = 0.579).

Conclusions: When the air-filled cuff of the standard endotracheal tube is repeatedly deflated every 30 min for 4 h, but not for only 3 h, during nitrous oxide anaesthesia, a stable cuff pressure can be achieved without further deflation of the cuff. Our data also suggest that achieving an equilibrating nitrous oxide concentration in the cuff provides a subsequent stable cuff pressure.

Summary

Background and objective: Advancing an uncut endotracheal tube into the right main bronchus produces unilateral breath sounds. We wanted to test the validity of using this method to distinguish oesophageal from tracheal intubation.

Methods: Forty-two patients were randomized into two groups. The first group was randomized to receive an endotracheal tube that was advanced into the right main bronchus. The second group of patients had their tracheas intubated as normal and then a second endotracheal tube was placed in the oesophagus. Blinded observers were then asked to decide by auscultation if the patients had unilateral breath sounds or not and if they were bronchial and therefore to decide if endotracheal intubation had occurred.

Results: Ninety-one per cent of patients (95% CI 0.71–0.99) intubated in the right main bronchus were correctly identified by unilateral breath sounds confirming the usefulness of this test.

Conclusions: Advancing an endotracheal tube into the right main bronchus and auscultation of unilateral breath sounds is a useful way of confirming tracheal intubation.

Summary

Background and objective: Regional anaesthesia has not been recommended as an anaesthetic method for penetrating eye injuries because it is suspected to aggravate the injury already present. After having successfully managed the treatment of a penetrating eye injury under combined peri- and retrobulbar block in an ASA IV patient, it was decided to evaluate this anaesthetic method further in the treatment of such emergency cases.

Methods: Twenty adult patients with penetrating eye injuries with a maximum wound length of 8 mm extending up to 4 mm posteriorly from the limbus were operated on under combined peri- and retrobulbar anaesthesia. Eighteen patients receiving general anaesthesia served as controls.

Results: The mean (range) volume injected for a satisfactory peribulbar retrobulbar block was 7.4 (6.5–8.0) mL, six patients needed an additional retrobulbar injection before surgery (2.9, range 2–4, mL). All patients receiving regional anaesthesia were satisfied with the anaesthetic method and the surgeons considered the surgical conditions as good. No problems relating to local anaesthesia were observed or reported by any of the patients.

Conclusions: In the hands of an experienced anaesthesiologist and under certain conditions, regional anaesthesia appears to be suitable for adult patients having penetrating eye injuries.

Summary

Background and objective: Although midazolam is commonly given orally to infants and small children for premedication, the taste is sometimes unacceptable even when mixed with syrup. We tested the efficacy and safety of oral fentanyl compared with oral midazolam in a randomized open-label study.

Methods: Fifty-one children, aged 12–107 months and weighing 10–25 kg, were randomly assigned to fentanyl or midazolam treatment groups. Midazolam (5 mg) or fentanyl (0.1 mg) was given orally from a small bottle with a small orifice 30 min before transfer to the preoperative holding room. The excitation–sedation conditions of the patients were assessed before and after general anaesthesia.

Results: The preoperative scores did not differ significantly between the two groups. No major complications were observed in either group. Postoperative vomiting occurred in 5 of 27 (18.5%) patients treated with oral fentanyl and in none of 24 of those treated with midazolam.

Conclusions: Oral administration of fentanyl 30 min before entrance to the holding room for an operation from a bottle with a small orifice is a premedication option for children between 1 and 8 yr of age.

Summary

Background and objective: Pain is often experienced when propofol is injected, and intravenous lidocaine is often effective in preventing such pain. We decided to determine whether metoprolol, given before the injection of propofol, is as effective as lidocaine in reducing the incidence and severity of the pain.

Methods: Ninety patients scheduled for elective surgery under general anaesthesia were randomly allocated to one of three groups to receive either metoprolol 2 mg, lidocaine 20 mg or saline 2 mL before any propofol was injected. Each patient was given one of these agents intravenously via a 20-G cannula on the dorsum of the hand whilst the venous drainage was occluded manually, at the middle of the forearm, for 45 s. After the occlusion was released, propofol 2.0–2.5 mg kg−1, at room temperature, was injected at 2 mL (20 mg) every 4 s. Pain was assessed verbally and scored as none (0), mild (1) or severe (2).

Results: The incidence of severe pain in the control group (56.7%) was significantly higher than in the metoprolol and lidocaine groups (16.6 and 10%, respectively). The number of patients who were free of pain was significantly higher in those who had been given either metoprolol or lidocaine.

Conclusions: Pretreatment with intravenous metoprolol was equally as effective as lidocaine in reducing the pain associated with propofol injection.

Summary

Background and objective: The study compared the analgesic efficacy and safety of two preoperatively administered cyclo-oxygenase-2 inhibitors, celecoxib and rofecoxib.

Methods: Ninety adult patients undergoing thyroid surgery were divided into three groups (each n = 30). They were given a single oral dose of placebo, celecoxib 200 mg or rofecoxib 50 mg 1 h before induction of anaesthesia. All patients received a standard anaesthetic. Intraoperative blood loss was measured. Pain scores, sedation scores, heart rate, mean arterial pressure and respiratory rate were noted at 0, 1, 2, 4, 6, 12 and 24 h postoperatively. Analgesic (meperidine) requirements and adverse effects were recorded during the first postoperative 24 h.

Results: Compared with placebo, pain scores were significantly lower with rofecoxib at all time points (P < 0.05) and were significantly lower with celecoxib (P < 0.05) during the first 4 h. Pain scores were significantly lower with rofecoxib compared with celecoxib at 6, 12 and 24 h (P < 0.05). The average cumulative 24 h meperidine dose was significantly lower with both celecoxib (54.9 ± 34.4 mg) and rofecoxib (42.8 ± 40.9 mg) compared with placebo (76.8 ± 6.2 mg) (P < 0.01 and P < 0.001, respectively). There were no differences in the intraoperative blood loss, heart rate, mean arterial pressure, respiratory rate, sedation scores and incidence of adverse effects among groups.

Conclusions: The preoperative administration of rofecoxib 50 mg and less so of celecoxib 200 mg provide a significant analgesic benefit with regard to postoperative pain relief and decrease in additional opioid requirements after thyroid surgery.