Impact of the Hawthorne effect in a longitudinal clinical study: the case of anesthesia

Clinical research can be influenced by many factors that are capable of invalidating results, and one of these factors is known as the Hawthorne effect: the mere awareness of being under observation can alter the way in which a person behaves. In experimental research this effect can be the undesired effect of the experiments themselves, and the stronger its presence, the greater it can influence the results. In anesthesia practice, owing to the particular emotional condition of a patient facing a surgical operation, the Hawthorne effect could be especially strong. The aim of our study was to show the impact that the knowledge of being included in a study has (Hawthorne effect), by comparing the postoperative changes in psychological well-being in two groups of patients undergoing knee arthroscopy and receiving different information about the study from the anesthetist during the preoperative interview. Other signs and symptoms such as postoperative knee pain, nausea, vomiting (the most feared occurrences), headache, return of spontaneous diuresis, analgesic request, anesthesia complications, as well as the intensity of anxiety were also assessed as secondary endpoints.Our results show that subjects who were aware that they were part of a study scored significantly better on postoperative measures of psychological well-being and postoperative knee pain, compared to subjects who were unaware. The size of the effect, as measured by the odds ratio, remains unchanged when controlling for potential confounding factors. The study has enabled us to demonstrate the presence of the Hawthorne effect in clinical research. Therefore, the Hawthorne effect should be acknowledged and accounted for in the design of a study and in the interpretation of results.     

Simultaneous curative resection of double colorectal carcinoma with synchronous bilobar liver metastases

Synchronous colorectal carcinoma (SCRC) indicates more than one primary colorectal carcinoma (CRC) discovered at the time of initial presentation, accounts for 3.1%-3.9% of CRC, and may occur either in the same or in different colorectal segments. The accurate preoperative diagnosis of SCRC is difficult and diagnostic failures may lead to inappropriate treatment and poorer prognosis. SCRC requires colorectal resections tailored to individual patients, based on the number, location, and stage of the tumours, from conventional or extended hemicolectomies to total colectomy or proctocolectomy, when established predisposing conditions exist. The overall perioperative risks of surgery for SCRC seem to be higher than for solitary CRC. Simultaneous colorectal and liver resection represents an appealing surgical strategy in selected patients with CRC and synchronous liver metastases (CRLM), even though the cumulative risks of the two procedures need to be adequately evaluated. Simultaneous resections have the noticeable advantage of avoiding a second laparotomy, give the opportunity of an earlier initiation of adjuvant therapy, and may significantly reduce the hospital costs. Because an increasing number of recent studies have shown good results, with morbidity, perioperative hospitalization, and mortality rates comparable to staged resections, simultaneous procedures can be selectively proposed even in case of complex colorectal resections, including those for SCRC and rectal cancer. However, in patients with multiple bilobar CRLM, major hepatectomies performed simultaneously with colorectal resection have been associated with significant perioperative risks. Conservative or parenchymal-sparing hepatectomies reduce the extent of hepatectomy while preserving oncological radicality, and may represent the best option for selected patients with multiple CRLM involving both liver lobes. Parenchymal-sparing liver resection, instead of major or two-stage hepatectomy for bilobar disease, seemingly reduces the overall operative risk of candidates to simultaneous colorectal and liver resection, and may represent the most appropriate surgical strategy whenever possible, also for patients with advanced SCRC and multiple bilobar liver metastases.     

An update on topical haemostatic agents in liver surgery: systematic review and meta analysis

Mortality and morbidity in hepatic surgery are affected by blood loss and transfusion. Topical haemostatic agents (THA) are composed by a matrix and/or fibrin sealants, and their association known as “carrier‐bound fibrin sealant” (CBFS): despite widely used for secondary haemostasis, the level of evidence remains low. To realize a meta‐analysis on the results of CBFS on haemostasis and postoperative complications. Searches in PubMed, PubMed Central, Cochrane and Google Scholar using keywords: “topical_haemostasis” OR “haemostatic_agents” OR “sealant_patch” OR “fibrin_sealant” OR “collagen_sealant” AND “liver_surgery” OR “hepatic_surgery” OR “liver_transplantation”. Randomized clinical trials, large retrospective cohort studies, case control studies evaluating THA on open/laparoscopic liver surgery and transplantation. From 1993 to 2016 were found 22 studies for qualitative synthesis and 13 for quantitative meta‐analysis. The time to haemostasis was lower in the CBFS group (mean difference ?2.33 min; P = 0.00001). The risk of receiving blood transfusion, developing collections and bile leak was not influenced by the use of CBFS (OR 0.75; P = 0.25), (OR 0.72; P = 0.52), (OR 0.74; P = 0.30) respectively. The use of CBFS in liver surgery significantly reduce the time to haemostasis, but does not decrease transfusion, postoperative collection and bile leak.     

Acute Guillain-Barré syndrome associated with asymptomatic HIV infection.

A 25-year-old male drug addict presented with a rapidly progressive ascending tetraplegia, requiring assisted ventilation. One month earlier he had fever (40 degrees C) and asthenia. Cerebrospinal fluid (CSF) examination showed elevated albumin level and albuminocytologic dissociation. HIV testing was positive in both serum and CSF. Plasma exchange therapy only partially improved the symptomatology. After five months the patient remained with a moderate tetraparesis. Differences between this and other cases of Guillain-Barré syndrome in HIV-seropositive patients reported in the literature are discussed.