Placebo effects on nausea and motion sickness are resistant to experimentally-induced stress.

Nausea often occurs in stressful situations, such as chemotherapy or surgery. Clinically relevant placebo effects in nausea have been demonstrated, but it remains unclear whether stress has an impact on these effects. The aim of this experimental study was to investigate the interplay between acute stress and placebo effects in nausea. 80 healthy female volunteers susceptible to motion sickness were randomly assigned to either the Maastricht Acute Stress Test or a non-stress control condition, and to either placebo treatment or no treatment. Nausea was induced by a virtual vection drum and behavioral, psychophysiological as well as humoral parameters were repeatedly assessed. Manipulation checks confirmed increased cortisol levels and negative emotions in the stressed groups. In the non-stressed groups, the placebo intervention improved nausea, symptoms of motion sickness, and gastric myoelectrical activity (normo-to-tachy (NTT) ratio). In the stressed groups, the beneficial effects of the placebo intervention on nausea and motion sickness remained unchanged, whereas no improvement of the gastric NTT ratio was observed. Results suggest that placebo effects on symptoms of nausea and motion sickness are resistant to experimentally-induced stress. Stress most likely interfered with the validity of the gastric NTT ratio to measure nausea and thus the gastric placebo effect.

Malignant middle cerebral artery syndrome with thrombotic thrombocytopenia following vaccination against SARS-CoV-2.

Cases of thromboses at unusual sites with thrombocytopenia have been reported following vaccination against Sars-CoV-2. This new syndrome, christened vaccine-induced thrombotic thrombocytopenia (VITT), mainly results in venous thromboses. We report the case of a young woman with a right middle cerebral artery stroke following vaccination with ChAdOx1 nCoV-19. A diagnosis of VITT was made and platelet counts began to recover shortly after commencing treatment with argatroban, intravenous immunoglobulins and corticosteroids. On day 6 following admission, the patient deteriorated neurologically and decision made to proceed with decompressive hemicraniectomy. There were no perioperative complications and anticoagulation with argatroban was reinitiated on the first postoperative day. VITT is a rare condition resembling auto-immune heparin-induced thrombocytopenia. All critical care staff should be aware of the rare link between vaccination against SARS-CoV-2 and VITT and the need to rapidly commence both anticoagulation, using heparin alternatives, and immunomodulation.

Individual Factors Contributing to Nausea in First-Time Chemotherapy Patients: A Prospective Cohort Study.

OBJECTIVE: The expectation of developing side effects can enhance the likelihood to develop them - a phenomenon referred to as nocebo effect. Whether nocebo effects can be reduced by lowering negative expectancies, is not clear. The aim of this prospective study was to learn more about the factors contributing to nausea expectancy and their potential role in actual occurrence of nausea in patients undergoing chemotherapy for the first time in their life. METHODS: Patients scheduled for moderately emetogenic chemotherapeutic regimens filled in questionnaires to assess state anxiety and quality of life and to rate the expectancy of nausea as a side effect of chemotherapy. Patient diaries were used to monitor the severity of post-chemotherapy nausea in the 4 days following chemotherapy administration. Bivariate analyses complemented by multiple regression analyses were performed to identify the relationship between nausea expectation and nausea occurrence. RESULTS: 121 female patients (mean age 53 years) with completed questionnaires were included in the analyses. The majority of the patients had a diagnosis of breast cancer (86%). The two main sources for nausea expectancy were positive history of nausea in other situations and state anxiety. Patients with high expectancy levels (first quartile) experienced greater nausea than those with lower expectancy levels. Bivariate analyses revealed a weak but non-significant association between nausea expectation and post-chemotherapy nausea. When controlling for age, type of cancer, history of nausea, state and trait anxiety, and global quality of life, positive history of nausea (OR = 2.592; 95% CI, 1.0 to 6.67; p < 0.05), younger age (OR = 0.95; 95% CI, 0.92 to 0.99; p < 0.05), and a lower quality of life (OR = 0.97; 95% CI, 0.94 to 1.0; p < 0.05), but not nausea expectancy (OR = 1.014; 95% CI, 0.51 to 2.02; p = 0.969), predicted the occurrence of post-chemotherapy nausea. CONCLUSION: In this female cohort, younger patients with lower initial quality of life and a positive history of nausea were at higher risk to develop nausea after first time chemotherapy. These patients may benefit from psychological co-interventions that aim to enhance quality of life.