Objective To report data about “real-life” treatments with non-invasive ventilation for acute respiratory failure (ARF), managed outside intensive care units by anaesthesiologists acting as a medical emergency team. Design Observational study; prospectively collected data over a 6-month period in a single centre. Setting Non-intensive wards in a University Hospital with 1,100 beds. Patients Consecutive patients with ARF for whom a ventilatory support was indicated but tracheal intubation was not appropriated or immediately needed. Interventions None. Measurements and results Patient’s characteristics, safety data, short-term outcome and organizational aspects of 129 consecutive treatments were collected. The overall success rate was 77.5%, while 10.1% were intubated and 12.4% died (all of them were “do not attempt resuscitation” patients). The incidence of treatment failure varied greatly among different diseases. Complications were limited to nasal decubitus (5%), failure to accomplish the prescribed ventilatory program (12%), malfunction of the ventilator (2%) and excessive air leaks from face mask (2%) with no consequences for patients. Three patients became intolerant to NIV. The work-load for the MET was high but sustainable: on average NIV was applied to a new case every 34 h and more than three patients were simultaneously treated. Conclusions Under the supervision of a MET, in our institution NIV could be applied in a wide variety of settings, outside the ICU, with a high success rate and with few complications.

INTRODUCTION:We describe and quantify the wide range of activities that a mature Medical Emergency Team can progressively perform.METHODS:The activities performed by a Medical Emergency Team 20 years after its introduction were prospectively collected during 105 consecutive days.RESULTS:The main activity was focused on the follow-up visits to previously treated critically ill patients (mean 7.5 visits/die in working days, 5.1 in the others). A large amount of other scheduled or unscheduled activities (like sedation or analgesia for diagnostic procedures, central venous line placement, phone consultation regarding critical care aspects of treatments) were performed: on average, 7.3 side-activities/die in working days and 5.2 in the others. First consultations in patients not previously seen were on average 3.1/die on working days, 2.4 in the others. Cardiac arrest accounted for 27 (9%) of first time visits.CONCLUSIONS:A Medical Emergency Team can progressively perform many kinds of activities. An evaluation limited to the reduction of in-hospital cardiac arrests or a too early assessment may underestimate its beneficial effects on the Hospital complexity.

This article reports two cases of dilatative percutaneous tracheostomy performed on patients treated with double antiplatelet therapy. Both patients had cardiac arrest following myocardial infarction. After primary angioplasty with stent placement, a double antiplatelet therapy was started. Due to poor neurological outcome, dilatative percutaneous tracheostomy was performed on both patients. Antiplatelet therapy was not discontinued because of the unacceptable risk of stent thrombosis. No immediate or late hemorrhagic complications occurred. In our experience, dilatative percutaneous tracheostomy during double antiplatelet therapy can be safely performed in selected patients without other risk factors.

Bergonzi, P. C.; Ruggieri, F.; Garozzo, A. F.; Martani, C.; Valeri, R. Author Information

Aim. The aim of this paper was to compare wash-in and wash-out curves of desflurane in morbidly obese and nonobese patients.Methods. Fourteen patients (7 obese and 7 nonobese) were studied. In the nonobese patients, anaesthesia was started by administering 2 mg/kg propofol bolus and a target controlled effect site concentration of remifentanil set at 2.5 ng/mL. Obese patients were intubated using a flexible fiberoptic bronchoscopic technique facilitated by a target controlled effect site concentration of remifentanil set at 2.5 ng/mL. After endotracheal intubation, general anaesthesia was started by administering a 1.5 mg/kg propofol bolus dose. Ten minutes after induction of anaesthesia, 4% desflurane was administered for 30 min. Desflurane kinetics was determined by collecting end-tidal samples from first breaths at 1, 5, 10, 15, 20, 25 and 30 min. At last skin suture, the end-tidal concentration of desflurane was recorded from 5 consecutive breaths before their discontinuation, then the end-tidal samples of the inhalational agent were collected at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 and 5 min after terminating its administration. The period of time from discontinuation of desflurane to opening eyes, squeezing the observer's hand, extubation, stating the patients' name and providing date of birth was also recorded.Results. The FA/FI ratio was higher in the nonobese group from the 10th to the 15th min. Wash-out curves of desflurane and recovery times were similar.Conclusion. Our results show that desflurane provides similar kinetic and recovery profiles in obese and nonobese patients.

BACKGROUNDThe aim of this study was to assess the predictive performance of 'Servin's formula' for bispectral index (BIS)-guided propofol-remifentanil target-controlled infusion (TCI) in morbidly obese patients.METHODSTwenty patients (ASA physical status II-III, age 32-64 yr) undergoing bilio-intestinal bypass surgery, were recruited. Anaesthesia was induced by using a TCI of propofol with an initial target plasma concentration of 6 microg ml(-1), then adapted to maintain stable BIS values ranging between 40 and 50. A TCI of remifentanil was added to achieve pain control and haemodynamic stability. For propofol, weight was corrected as suggested by Servin and colleagues. With ideal body weight (IBW) corrected according to formula suggested by Lemmens and colleagues. For remifentanil, weight was corrected according to IBW. Arterial blood samples for the determination of blood propofol concentrations were collected at different surgical times. The predictive performance of propofol TCI was evaluated by examining performance accuracy.RESULTSMedian prediction error and median absolute prediction error were -32.6% (range -53.4%; -2.5%) and 33.1% (10.8%; 53.4%), respectively. Wobble median value was 5.9% (2.5%; 25.2%) while divergence median value was -1.5% h(-1) (-7.7; 33.8% h(-1)).CONCLUSIONSignificant bias between predicted and measured plasma propofol concentrations was found while the low wobble values suggest that propofol TCI system is able to maintain stable drug concentrations over time. As already suggested before, a computer simulation confirmed that the TCI system performance could be significantly improved when total body weight is used.

Turi, S.; Gemma, M.; Albertin, A.; Poli, D.; Bergonzi, P C.; Dedola, E. Author Information

La Colla, L.; Albertin, A.; Dedola, E.; Bergonzi, P. C.; Poli, D.; Salaris, D. Author Information

Dedola, E.; Poli, D.; Albertin, A.; Bergonzi, P. C.; Pasculli, N.; Turi, S. Author Information

Background and objectives: The aim of this prospective, randomized, double-blind study was to determine the effects of adding two different target-controlled concentrations of remifentanil (1 and 3 ng mL(-1)) on the desflurane requirement for blunting sympathetic responses after surgical incision (minimum anaesthetic concentration (MAC(BAR))). Methods: 67 patients, aged 20-50 yr, ASA I, undergoing general anaesthesia for elective abdominal surgery were enrolled and randomly allocated to receive no remifentanil infusion (n = 21) or a target-controlled effect-site concentrationof 1 ng mL(-1) (n = 24)or 3 ng mL(-1) remifentanil (n = 22). All patients were anaesthetized with propofol, cisatracurium and desflurane with a mixture of 60% nitrous oxide in oxygen. Sympathetic responses to surgical incision were determined after a 20-min period of stable end-tidal desflurane and target-controlled remifentanil concentrations. Predetermined end-tidal desflurane concentrations and the MACBAR for each group were determined using an up-and-down sequential-allocation technique. Results: The MACBAR of desflurane was higher in the group receiving no remifentanil (6.25% [95% confidence interval: 5.9-6.5%]) as compared with patients of the groups receiving 1 ng mL(-1) (2.7% [2.6-2.8%]; P < 0.001) and 3 ng mL(-1) remifentanil (2% [1.9-2.2%]; P < 0.01). When considering a MAC value in this age population and the contribution of 60,76 nitrous oxide (0.55 MAC), the combined MACBAR values, expressed as multiples of the MAC, were 1.9, 0.8 and 0.6 MAC, in the three groups, respectively. Conclusion: A target-controlled concentration of 1 ng mL(-1) remifentanil results in a 57% decrease in the MACBAR of desflurane combined with 60% nitrous oxide. Increasing the target concentration of remifentanil to 3 ng mL(-1) produces a further 26% decrease in the MACBAR values of desflurane.

Cristallo, E.; Poli, D.; Elisa, D.; Albertin, A.; Bergonzi, P. C.; Turi, S. Author Information

AIM:The aim of this prospective study was to determine the effect site concentrations of remifentanil maintaining cardiovascular homeostasis in response to surgical stimuli during bispectral index (BIS) guided propofol anesthesia in seriously obese patients.METHODS:Twenty-two patients, female/male 15/7, ASA physical status II - III, aged 29-69 years, body mass index (BMI) 54.5+/-12, undergoing major open bariatric surgery, were enrolled to receive a propofol-remifentanil total intravenous anesthesia. All patients were intubated by using a flexible fiberoptic bronchoscopic technique facilitated by a target controlled effect site concentration of remifentanil set at 2.5 ng/mL. After endotracheal intubation, anesthesia was started with a target controlled infusion of propofol initially set at 6 microg/mL, then adjusted to maintain a BIS value between 40 and 50. The mean effect site concentration of remifentanil was recorded at different intervals time during surgery: skin incision-opening of peritoneum (T1), bowel resection (T2), cholecystojejunal anastomosis (T3), ileojejunal anastomosis (T4), closing of peritoneum (T5).RESULTS:The mean plasma concentrations of propofol required to maintain a BIS value between 40 and 50 were 4+/-0.55, 3.8+/-0.64, 3.8+/- 0.63, 3.8+/-0.65 and 3.8+/-0.63 microg/mL at T1, T2, T3, T4 and T5 interval time, respectively. The mean values of remifentanil target effect site concentration were 5.2+/-1.3, 7.7+/-1.7, 9.1+/-1.8, 9.7+/- 2.2 and 9.9+/-2.5 ng/mL at T1, T2, T3, T4 and T5 interval time.CONCLUSIONS:This study suggests that tolerance to remifentanil infusion is profound and develops very rapidly in morbidly obese patients submitted to open bariatric surgery during BIS guided propofol anesthesia. The administration of opiates during anesthesia based on target-controlled infusion should include corrections for the development of tolerance.

La Colla, L.; Albertin, A.; Bergonzi, P C.; Poli, D.; Dedola, E.; Rotta, S. Author Information

AIM Reoperative coronary artery bypass grafting is associated with significant morbidity and a difficult perioperative management; in particular, important bleeding is observed. Off pump technique may give specific advantages in redo coronary operations since it is associated to decreased interactions of blood with foreign surfaces. We investigated our 5-year database to evaluate the role of off pump technique in reducing transfusion needs. METHODS The present single centre case control study was carried out in a university tertiary care hospital on 132 consecutive patients undergoing reoperative coronary artery bypass grafting off pump (OP group, 41 patients) or with cardiopulmonary bypass (CPB group, 91 patients). Univariate and multivariate analysis were performed. RESULTS There was no preoperative difference between the 2 groups; mean number of grafts per patient differed between groups (OP: 1.4+/-0.7, CPB: 2.5+/-1.0). The frequency of patients transfused with blood products was significantly (P=0.004) higher in the CPB group (47.3%) than in the OP group (19.5%). The only independent predictors of transfusions, determined by stepwise multivariate logistic regression analysis, was the use of cardiopulmonary bypass (OR: 4.1, CI: 1.6 - 10.1), and female gender (OR: 7.0, CI: 2.1 - 16.1). CONCLUSION In our centre, off pump coronary surgery is associated with reduced transfusion of blood products.

BACKGROUND AND OBJECTIVE:The aim of this prospective, randomized, double-blind study was to determine the effects of adding nitrous oxide on sevoflurane requirement for blunting sympathetic responses after surgical incision combined with two different target-controlled concentrations of remifentanil (1 and 3 ng mL(-1)) in female.METHODS:102 female patients, aged 20-50 yr, ASA I, undergoing general anaesthesia for elective abdominal surgery were enrolled and randomly allocated to receive sevoflurane anaesthesia alone (Group A, n=53), or with the addition of 60% nitrous oxide (Group N, n=49). Patients of both groups were further assigned to receive a target-controlled remifentanil infusion with an effect-site concentration of either 1 ng mL(-1) (Group N1, n=27; Group A1, n=30), or 3 ng mL(-1) (Group N3, n=22; Group A3, n=23). Sympathetic responses to surgical incision were determined after a 20-min period of stable end-tidal sevoflurane and target-controlled remifentanil concentrations. Predetermined end-tidal sevoflurane concentrations and minimum alveolar concentration (MAC) for each group were determined using an up-and-down sequential allocation technique.RESULTS:The MAC of sevoflurane was 3.96% (95% confidence interval, CI95: 3.69-4.23%) in Group A1 and 1.2% (CI95: 0.9-1.3%) in Group N1 (P < 0.01), while in Groups A3 and N3 the MAC of sevoflurane was 0.36% (CI95: 0.24-0.47%) and 0.18% (CI95: 0.1-0.3%), respectively (P < 0.05).CONCLUSION:Adding 60% nitrous oxide reduces the MAC of sevoflurane by 70% when using a remifentanil concentration of 1 ng mL(-1) and 50% when using a remifentanil concentration of 3 ng mL(-1).

Aim. Opioid and N 2 O reduce the minimum alveolar concentration of inhalation agents preventing cardiovascular response to skin incision (MAC-BAR) 1 . This prospective, randomised, blind study evaluate the effect of 2 concentrations of remifentanil on the MAC-BAR of sevoflurane without nitrous. Methods. The MAC-BAR of sevoflurane was measured with an up-and-down sequential allocation technique 2 in 49, 20 and 50 years-old female patients, ASA I, undergoing general anesthesia for elective abdomen surgery and randomly assigned to receive 1 ng/ml remifentanil (group 1, n=28) or 3 ng/ml (group 3, n=21) as effect site concentration by a target concentration infusion device (Rugloop software).The response was considered positive when the HR or MAP increased 15% or more compared to preincisional values. Results. The MAC-BAR of sevoflurane was 3.96%′0.17% in Group 1 and 0.36%′0.09% in Group 3 (P<0,01). Figure 1 shows the relationships between MAC-BAR and remifentanil plasma concentration. Conclusion. According to the definition of MAC-BAR all points of the relationships shown in Figure 1 represent similar equipotent levels of surgical anesthesia. To prevent awareness a value of sevoflurane alveolar concentration may be chosen between 1 and 1,5%, When these values are used a remifentanil concentration ranging between 2, 4 and 2.65 ng/ml should be used. This study indicate the correct approach to the clinical use of this drug combination providing an adeguate level of surgical anesthesia when N 2 O is omitted and preventing awareness because MAC-BAR is higher than MACawake.