Femoral nerve blockade versus local infiltration analgesia for primary knee arthroplasty. Randomised controlled trial.

INTRODUCTION: Total knee arthroplasty (TKA) is associated with severe postoperative pain and significant chronification. The lengthy debate is on-going regarding the best balance between pain management, safety, and functional rehabilitation. MATERIAL AND METHODS: Fifty adult patients scheduled for primary unilateral TKA were randomly divided into 2 groups: continuous femoral nerve blockade (FNB; n = 25) and local infiltration analgesia (LIA; n = 25). We compared FNB and LIA in terms of function (primary outcome; number of steps, recorded using a step-tracking watch), pain scores using the visual analogue scale (VAS), opioid consumption (morphine equivalents), muscle strength (Janda Score), side effects, and complications until postoperative day 5. The results are presented as (mean ± SD). RESULTS: After excluding one patient, 49 were analysed (25 FNB, 24 LIA). There were no differences between the groups in the primary outcome. The VAS score (day 0: 23 ± 17.7 vs. 32.8 ± 21.5; P = 0.101; day 1: 31.0 ± 22.3 vs. 41.7 ± 25.3; P = 0.112) and mean opioid consumption (day 0: 0.39 ± 0.17 vs. 0.50 ± 0.38; P = 0.655; day 1: 0.60 ± 0.27 vs. 0.71 ± 0.38; P = 0.406) did not differ significantly between the groups. Muscle strength was significantly lower in the FNB group on days 0 (3.05 ± 1.67 vs. 4.35 ± 0.91; P = 0.009) and 1 (2.71 ± 1.57 vs. 3.67 ± 1.18; P = 0.030). Side effects and complications had a similarly low incidence in both groups, and except for constipation (FNB < LIA) no difference was seen. CONCLUSIONS: Based on the results of this study, both FNB and LIA are associated with similar outcomes, and one cannot be recommended over the other.

Pre- and intraoperative cerebral near-infrared spectroscopy and postoperative delirium: Results of a prospective cross-sectional trial.

Postoperative delirium (PODE) is a serious complication that can occur during the first few days after surgery. A number of causes can make delirium more likely; one factor to consider is hypoxia during anesthesia. In this study, the pre- and intraoperative cerebral regional oxygen saturation (rSO2) as measured by near-infrared spectroscopy (NIRS) was to be examined with regard to an association with the occurrence of PODE in patients undergoing major abdominal procedures. Data from 80 patients (33 women, 47 men) was examined. The mean age was 66.31 ± 10.55 years (between 42 and 84 years). Thirteen patients developed PODE. The preoperative rSO2 values (P = .10) and the rSO2 values during the steady state of anesthesia (P = .06) tended to be lower in the delirium group than in the non-delirium group. There was a significant correlation between the preoperative rSO2 and the preoperative hemoglobin values (P < .001). The variance of rSO2 during the steady state of anesthesia was significantly greater in the delirium group compared to the non-delirium group (P = .03). In two patients from the delirium group, rSO2 dropped below 50%; they also had a minimum mean arterial pressure below 50 mm Hg, which could have disturbed cerebral autoregulation. The duration of rSO2 decreases (>10%, >15%, >20%) and increases (>10%) compared to the preoperative values was not significantly different between patients with and without PODE. The results suggest that NIRS could be a useful monitoring method for patients undergoing abdominal surgical procedures, on the one hand to recognize patients with low pre- or intraoperative rSO2 values, and on the other hand to detect changes in rSO2 values during anesthesia.

Intraoperative monitoring parameters and postoperative delirium: Results of a prospective cross-sectional trial.

ABSTRACT: Postoperative delirium (PODE) can be associated with severe clinical complications; therefore, preventive measures are important. The objective of this trial was to elucidate whether haemodynamic or electroencephalographic (EEG) monitoring parameters during general anaesthesia or sevoflurane dosage correlate with the incidence of PODE. In addition, sevoflurane dosages and EEG stages during the steady state of anaesthesia were analyzed in patients of different ages.Eighty adult patients undergoing elective abdominal surgery received anaesthesia with sevoflurane and sufentanil according to the clinical routine. Anaesthesiologists were blinded to the EEG. Haemodynamic parameters, EEG parameters, sevoflurane dosage, and occurrence of PODE were analyzed.Thirteen patients (4 out of 33 women, 9 out of 47 men) developed PODE. Patients with PODE had a greater mean arterial pressure (MAP) variance (267.26 (139.40) vs 192.56 (99.64) mmHg2, P = .04), had a longer duration of EEG burst suppression or suppression (27.09 (45.32) vs 5.23 (10.80) minutes, P = .03), and received higher minimum alveolar sevoflurane concentrations (MAC) (1.22 (0.22) vs 1.09 (0.17), P = .03) than patients without PODE. MAC values were associated with wide ranges of EEG index values representing different levels of hypnosis.The results suggest that, in order to prevent PODE, a great variance of MAP, higher doses of sevoflurane, and deep levels of anaesthesia should be avoided. Titrating sevoflurane according to end-tidal gas monitoring and vital signs can lead to unnecessarily deep or light hypnosis. Intraoperative EEG monitoring may help to prevent PODE.