In experimental trials, ketamine has been shown to reduce hyperalgesia, prevent opioid tolerance, and lower morphine consumption. Clinical trials have found contradictory results. We performed a review of randomized, double-blinded clinical trials of ketamine added to opioid in i.v. patient-controlled analgesia (PCA) for postoperative pain in order to clarify this controversy. Our primary aim was to compare the effectiveness and safety of postoperative administered ketamine in addition to opioid for i.v. PCA compared with i.v. PCA with opioid alone. Studies were identified from the Cochrane Library 2003, MEDLINE (1966-2009), and EMBASE (1980-2009) and by hand-searching reference lists from review articles and trials. Eleven studies were identified with a total of 887 patients. Quality and validity assessment was performed on all trials included using the Oxford Quality Scale with an average quality score of 4.5. Pain was assessed using visual analogue scales or verbal rating scales. Six studies showed significant improved postoperative analgesia with the addition of ketamine to opioids. Five studies showed no significant clinical improvement. For thoracic surgery, the addition of ketamine to opioid for i.v. PCA was superior to i.v. PCA opioid alone. The combination allows a significant reduction in pain score, cumulative morphine consumption, and postoperative desaturation. The benefit of adding ketamine to morphine in i.v. PCA for orthopaedic or abdominal surgery remains unclear. Owing to huge heterogeneity of studies and small sample sizes, larger double-blinded randomized studies showing greater degree of homogeneity are required to confirm these findings.

Sentinel lymph node (SN) biopsy is part of the staging procedure in breast cancer patients. In this study, we compared an intraoperative tool named one-step nucleic acid amplification (OSNA) to our routine histological investigation. OSNA consists of a short homogenization step followed by amplification of cytokeratin (CK) 19 mRNA directly from the lysate. To evaluate the performance of OSNA in comparison to histology, analysis of 343 axillary lymph nodes (ALN) from 93 breast cancer patients was performed with both methods. Discordant samples were subjected to other methods. If these tests supported the OSNA results, these samples were excluded from the study. The concordance rate was 91.8%, sensitivity 98.1%, and specificity 90.8% before and 95.5%, 100%, and 95.6%, respectively, after discordant case investigation. Our results show that OSNA is an excellent method for the detection of metastases in lymph nodes and can be applied as an intraoperative diagnostic approach.

There was a trend in favor of HD-CT with respect to event-free survival, but without statistical significance. Further follow-up and a meta-analysis of all randomized studies will reveal the effect of HD-CT as compared with SD-CT as adjuvant treatment in high-risk primary breast cancer.