Nausea: a review of pathophysiology and therapeutics

Clinical Response to Celiac Plexus Block Confirms the Neurogenic Etiology of Median Arcuate Ligament Syndrome

PURPOSE

To evaluate the response of median arcuate ligament syndrome (MALS) symptoms, including postprandial pain, nausea, and vomiting, to celiac plexus block (CPB) and correlate the response with arterial anatomy.

MATERIALS AND METHODS

In a single-institution, retrospective cohort of clinically diagnosed MALS patients, 96 patients (female, 75; male, 21; mean age, 27 years) underwent 103 computed tomography‒guided percutaneous CPB procedures. Imaging, procedural, and clinical reports were reviewed. Primary outcomes evaluated were technical success, change in self-reported pain score, and change in nausea and vomiting.

RESULTS

Computed tomography imaging before the procedure was available for 81 of 96 patients and demonstrated findings of celiac artery compression in 22 of 81 (27%) patients. Technical success was achieved in 102 of 103 cases. No major adverse events and 1 moderate adverse event were reported. The postprandial pain score decreased in 86 (84%) patients, and the mean score decreased from 6.3 to 0.9 points (P < .001). The prevalence of postprandial nausea decreased from 37.9% to 11.6% (P < .001) and that of vomiting decreased from 15.5% to 4.9% (P = .019). No differences were noted in pain relief after CPB between patients with and without celiac artery compression (P = .745).

CONCLUSIONS

In patients with a clinical diagnosis of MALS, a large majority reported pain relief and decreased gastrointestinal symptoms after CPB. Pain relief did not correlate with the presence of celiac arterial abnormalities. This supports neuropathy as the primary etiology of MALS and suggests that the absence of celiac stenosis should not be used as an exclusion criterion.

Meal-Induced Symptoms in Children with Dyspepsia-Relationships to Sex and the Presence of Gastroparesis

OBJECTIVES

To test the hypothesis that in children with dyspepsia, prospective symptom severity following ingestion of a meal would correlate with percent gastric retention, and those ultimately diagnosed with gastroparesis would report worse symptoms.

STUDY DESIGN

Prospective, single-center study with 104 children with dyspepsia completing a prospective dyspepsia symptom questionnaire before and after eating a standardized Tougas meal during gastric emptying scintigraphy. Main outcomes included correlation between gastric retention and symptoms and comparison of symptom severity between those with and without gastroparesis.

RESULTS

Fifty-two children (50%) had gastroparesis (gastroparesis: 12.5 ± 2.9 years, 65% female; nongastroparesis: 13.0 ± 2.9 years, 60% female; all P > .05). Bloating was the only symptom significantly worse in youth with gastroparesis. For the entire cohort, bloating and fullness correlated with percent retention. However, in those with gastroparesis, only nausea correlated with retention (4 hours.; r_s = 0.275, P < .05). Girls with gastroparesis had significantly worse symptoms (except satiety) when compared with boys with gastroparesis (P < .05).

CONCLUSIONS

Overall in children, there is little difference in symptom severity between children with gastroparesis vs normal emptying based on current standards. However, girls with gastroparesis have worse symptoms vs boys with gastroparesis, underscoring a need for further studies into the role of sex in gastroparesis symptoms. In all children, both bloating and fullness correlated modestly with gastric retention, and nausea correlated in those with gastroparesis.

Nausea and Vomiting in 2021: A Comprehensive Update

GOAL

A comprehensive review of treatments for nausea and vomiting (N/V).

BACKGROUND

N/V are common symptoms encountered in medicine. While most cases of acute N/V related to a specific cause can be straightforward to manage, other cases of acute N/V such as chemotherapy-induced N/V and especially chronic unexplained N/V can be difficult to control, leading to a significant decline in the patient's quality of life and increased cost of medical care from repeated hospitalizations.

STUDY

Traditional management has relied on pharmacotherapy which may be inadequate in a certain proportion of these patients. Many of the medications used in the management of N/V have significant side effect profiles making the need for new and improved interventions of great importance.

RESULTS

This review covers a broad review of the pathophysiology of N/V, pharmacotherapy, including safety concerns and controversies with established pharmaceuticals, newer immunotherapies, bioelectrical neuromodulation (including gastric electrical stimulation), behavioral and surgical therapies, and complementary medicine.

CONCLUSION

On the basis of emerging understandings of the pathophysiology of N/V, improved therapies are becoming available.

[Update nausea and vomiting amongst the elderly]

Nausea (like vomiting) is a symptom and not an independent disease pattern. This makes it difficult to give an accurate number of the incidences in the elderly population. Approximately every 2^nd to 3^rd elderly person is affected.There are many possible causes of nausea (cerebrally caused, cerebrally controlled or caused by gastrointestinal disease). The physiological aging of the gastrointestinal tract on its own does not cause nausea.The diagnosis is based on a detailed medical history and an in-depth physical examination. Further diagnostic steps have to be customized to each patient. An official guidelines for diagnostics is not established.Initially the therapy aims to treat the cause (underlying disease or polypharmacy). Symptom-oriented medication should only be considered as secondary meassure. However, numerous possible drugs are inadequate for elderly people.

Clinical features and gastric myoelectrical activity in patients with idiopathic and post-surgical rapid gastric emptying who present with unexplained chronic nausea

BACKGROUND

The cause of chronic nausea can be difficult to diagnose. Idiopathic rapid gastric emptying (iRGE) can cause nausea, but limited literature exists on clinical and pathophysiological features. In contrast, dumping syndrome or post-surgical rapid gastric emptying (psRGE) is well-known and may present with early phase vasomotor symptoms, diarrhea, and late phase reactive hypoglycemia. Our aim is to compare clinical and gastric motility characteristics in patients with iRGE and psRGE and unexplained chronic nausea.

METHODS

A retrospective study was conducted on patients with unexplained chronic nausea and RGE (<30% retention of a standard isotope-labeled solid meal at 1-h). Gastric myoelectrical activity (GMA) was recorded during water load satiety tests (WLST) using validated electrogastrogram (EGG) recording methods.

KEY RESULTS

Thirty iRGE and sixteen psRGE patients with unexplained chronic nausea were identified; average 1-hour meal retention was 18.6% and 16.2%, respectively. Nausea, bloating, early satiety, and bowel function were similar in the two groups; fewer iRGE patients had abdominal pain and none had vasomotor symptoms. Normal 3 cpm GMA was recorded in 44% of iRGE vs 29% of psRGE, tachygastria in 13% vs 43%, bradygastria in 25% vs 14%, and mixed in 19% vs 14% (p values >0.05). Abnormal WLST volume (<300 ml) was found in 69% of iRGE and 43% of psRGE (p = 0.36).

CONCLUSIONS & INFERENCES

(a) iRGE and psRGE patients may present with unexplained chronic nausea rather than classic vasomotor symptoms and diarrhea. (b) iRGE and psRGE patients had similar gastric dysrhythmias and accommodation dysfunction, which may contribute to RGE.

Supportive Care: Low Cost, High Value

Supportive care aims to prevent and manage adverse effects of cancer and its treatment across the entire disease continuum. Research and clinical experience in dedicated centers have demonstrated that early appropriate supportive care interventions improve symptoms, quality of life, and overall survival in a cost-effective manner. The challenge is to assess symptoms and needs with validated tools regularly and, ideally, between clinic appointments; electronic patient-reported outcome measures and dedicated easily accessible supportive care units can help. As management of certain problems improves, others come to the fore. Cancer-related fatigue and malnutrition are very frequent and need regular screening, assessment of treatable causes, and early intervention to improve. Pharmacologic agents and phytopharmaceuticals are of little use, but other interventions are valuable: physical exercise, counseling on fatigue, and cognitive behavioral therapy/mind-body interventions (e.g., for fatigue). Nutrition should be oral, rich in proteins, and accompanied by muscle training adapted to the patient's condition. Psychological and societal counseling is often useful; nausea or other problems such as gastrointestinal dysmotility or metabolic derangements must be tackled. Chemotherapy-induced peripheral neuropathy frequently worsens quality of life and has no established prevention strategy (notwithstanding current interest in cryotherapy and compression therapy) and thus requires careful assessment of patient predisposition to develop it with the consideration of feasible dose and treatment alternatives. When painful, duloxetine helps. Nonpharmacologic strategies, including acupuncture, physical exercise, cryotherapy/compression, and scrambler therapy, are promising but require large phase III trials to become the accepted standard. Personalization of chemotherapy, dependent on realistic goals, is key.

Prior transfusion of umbilical cord mesenchymal stem cells can effectively alleviate symptoms of motion sickness in mice through interleukin 10 secretion

BACKGROUND

Motion sickness (MS) is a disease that occurs during unbalanced movement, characterized by gastrointestinal symptoms and autonomic nervous system activation. Current clinical treatments for MS are limited. Recent evidence indicates that the levels of pro-inflammatory cytokines increase during MS and are associated with an inner ear immune imbalance. In the present study, mesenchymal stem cells (MSCs) have been shown to exert strong immuno-suppressive effects.

AIM

To explore whether umbilical cord-derived mesenchymal stem cells (UC-MSCs) can prevent the occurrence of MS, and the underlying mechanism regulated by MSCs in a mouse model of MS.

METHODS

A total of 144 (equal numbers of males and females) 5wkold BALB/c mice were randomly divided into five groups: Normal group (n = 16), MS group (n = 32), MSCs group (n = 32), MS + MSCs group (n = 32), and MS + AS101/MSCs group (n = 32). The MSCs group (n = 32), MS + MSCs group (n = 32), and MS + AS101/MSCs group (n = 32) were preventively transplanted with UC-MSCs or AS101-treated UC-MSCs (1 × 10⁶ cells/mouse). Mice in the MS (n = 32), MS + MSCs, and MS + AS101/MSCs groups were subjected to rotation on a centrifuge for 10 min at 8 × g/min for MS model establishment on days 3, 5, 8, and 10 after UC-MSCs injection. The Morris water maze (MWM) test was used to observe the symptom of dizziness. Enzyme-linked immunosorbent assay (ELISA) and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were used to detect the levels of inflammatory cytokines in mice peripheral blood and the petrous part of the temporal bone samples. Western blot analysis was performed to analyze the JAK2/STAT3 signaling pathway in the cochlear tissues. Histological examination was performed by hematoxylin and eosin (HE) staining for conventional morphological evaluation in the petrous part of temporal bone samples.

RESULTS

The MWM test demonstrated that UC-MSCs improved the symptoms of MS. The MS + MSCs group was faster than the MS group on days 3 and 5 (P = 0.036 and P = 0.002, respectively). ELISA and RT-qPCR showed that the serum and mRNA levels of interleukin-10 (IL-10) in the cochlear tissues were increased after transplantation with UC-MSCs (MS + MSCs group vs MS group at 3 and 5 d, P = 0.002 and ^cP < 0.001, respectively). RT-qPCR results confirmed a significant increase in IL-10 levels at four time points (MS + MSCs group vs MS group, P = 0.009, P = 0.009, P = 0.048, and P = 0.049, respectively). This suggested that UC-MSCs reduced the sensitivity of the vestibular microenvironment by secreting IL-10. Moreover, Western blot analysis showed that the MSCs activated the JAK2/STAT3 signaling pathway in the cochlear tissues. The levels of IL-10, IL-10RA, JAK2, STAT3, and phosphorylated JAK2 and STAT3 in the MS + MSCs group were increased compared to those of the MS group (P < 0.05). The morphological changes in the four groups showed no significant differences. The role of IL-10 secretion on the ability of UC-MSCs to successfully improve the symptoms of MS was confirmed by the diminished therapeutic effects associated with treatment with the IL-10 inhibitor ammonium trichloro (dioxoethylene-o,o′) tellurate (AS101).

CONCLUSION

Prophylactic transplantation of UC-MSCs can alleviate the clinical symptoms of MS in mice, particularly at 3-5 d after preventive transplantation. The mechanism for UC-MSCs to reduce the sensitivity of vestibular cortex imbalance may be the secretion of IL-10. The next step is to demonstrate the possibility of curing MS in the vestibular environment by intermittent transplantation of MSCs. Above all, MSCs are expected to become a new method for the clinical prevention and treatment of MS.

Risk factors associated with antineoplastic chemotherapy-induced nausea and vomiting

OBJECTIVE

To estimate the incidence and to evaluate risk factors for antineoplastic nausea and vomiting with high and moderate emetogenic chemotherapy in adult patients in the first treatment cycle.

METHODS

Prospective cohort study with follow-up of 269 adults during the first cycle of antineoplastic chemotherapy. The incidence of nausea and vomiting was evaluated in the acute phase (0-24 hours), in the late phase (24 hours-5th day) and in the total phase (0-5th day).

RESULTS

In total, 152 patients underwent high emetogenic chemotherapy and 117 moderate emetogenic chemotherapy. The relative frequency of nausea was higher when compared with vomiting in the acute phase (p < 0.001) and in the late phase (p < 0.001). The risk factors identified were: age group ≤ 49 years (odds ratio = 0.47; 95%CI 0.23-0.95) and 50-64 years (odds ratio = 0.45; 95%CI 0.23-0.87), tobacco use (odds ratio = 0.35; 95%CI 0.14-0.88), and high emetogenic chemotherapy (odds ratio 0.55; 95%CI 0.31-0.95).

CONCLUSION

The incidence of nausea was higher than that of vomiting, and adverse effects were more frequent in the late phase. The results suggest the risk factors for chemotherapy-induced nausea and vomiting are tobacco, age (young adults), and high emetogenic chemotherapy.

Marijuana, Ondansetron, and Promethazine Are Perceived as Most Effective Treatments for Gastrointestinal Nausea

BACKGROUND

Many anti-nausea treatments are available for chronic gastrointestinal syndromes, but data on efficacy and comparative effectiveness are sparse.

AIMS

To conduct a sectional survey study of patients with chronic nausea to assess comparative effectiveness of commonly used anti-nausea treatments.

METHODS

Outpatients at a single center presenting for gastroenterology evaluation were asked to rate anti-nausea efficacy on a scale of 0 (no efficacy) to 5 (very effective) of 29 commonly used anti-nausea treatments and provide other information about their symptoms. Additional information was collected from the patients' chart. The primary outcome was to determine which treatments were better or worse than average using a t test. The secondary outcome was to assess differential response by individual patient characteristics using multiple linear regression.

RESULTS

One hundred and fifty-three patients completed the survey. The mean efficacy score of all anti-nausea treatments evaluated was 1.73. After adjustment, three treatments had scores statically higher than the mean, including marijuana (2.75, p < 0.0001), ondansetron (2.64, p < 0.0001), and promethazine (2.46, p < 0.0001). Several treatments, including many neuromodulators, complementary and alternative treatments, erythromycin, and diphenhydramine had scores statistically below average. Patients with more severe nausea responded better to marijuana (p = 0.036) and diphenhydramine (p < 0.001) and less so to metoclopramide (p = 0.020). There was otherwise no significant differential response by age, gender, nausea localization, underlying gastrointestinal cause of nausea, and GCSI.

CONCLUSIONS

When treating nausea in patients with chronic gastrointestinal syndromes, clinicians may consider trying higher performing treatments first, and forgoing lower performing treatments. Further prospective research is needed, particularly with respect to highly effective treatments.

Recent advances with 5-HT3 modulators for neuropsychiatric and gastrointestinal disorders

Serotonin (5-hydroxytryptophan [5-HT]) is a biologically active amine expressed in platelets, in gastrointestinal (GI) cells and, to a lesser extent, in the central nervous system (CNS). This biogenic compound acts through the activation of seven 5-HT receptors (5-HT_1-7 Rs). The 5-HT₃ R is a ligand-gated ion channel belonging to the Cys-loop receptor family. There is a wide variety of 5-HT₃ R modulators, but only receptor antagonists (known as setrons) have been used clinically for chemotherapy-induced nausea and vomiting and irritable bowel syndrome treatment. However, since the discovery of the setrons in the mid-1980s, a large number of studies have been published exploring new potential applications due their potency in the CNS and mild side effects. The results of these studies have revealed new potential applications, including the treatment of neuropsychiatric disorders such as schizophrenia, depression, anxiety, and drug abuse. In this review, we provide information related to therapeutic potential of 5-HT₃ R antagonists on GI and neuropsychiatric disorders. The major attention is paid to the structure, function, and pharmacology of novel 5-HT₃ R modulators developed over the past 10 years.

The effect of prophylactic rewarming on postoperative nausea and vomiting among patients undergoing laparoscopic hysterectomy: a prospective randomized clinical study

BACKGROUND

Postoperative nausea and vomiting (PONV) is a common complication from general anesthesia that impacts on postoperative recovery.

OBJECTIVE

To evaluate prophylactic rewarming following general anesthesia, so as to decrease the incidence of PONV among patients undergoing laparoscopic hysterectomy.

DESIGN AND SETTING

Prospective randomized clinical study at a hospital in China.

METHODS

Sixty-two patients were randomly assigned into two groups. The forced air warming (FAW) group received pre-warmed Ringer's solution with FAW until the end of surgery. The control group received Ringer's solution without FAW. The pre-warmed Ringer's solution was stored in a cabinet set at 40 °C. The FAW tube was placed beside the patient's shoulder with a temperature of 43 °C.

RESULTS

Sixty patients completed the study. The FAW group showed significant differences versus the controls regarding temperature. At 6, 24 and 48 hours postoperatively, the incidences of PONV were 53.3%, 6.7% and 3.3% in the FAW group versus 63.3%, 30% and 3.3% in the controls. VAS scores were significantly lower in the FAW group than in the controls at 24 hours (P= 0.035). Forty-item questionnaire total scores in the FAW group were significantly higher than in the controls. The physical independence and pain scores at 24 hours and emotional support and pain scores at 48 hours in the FAW group were higher than in the controls (P < 0.05). There was no difference in hemodynamics or demographics between the two groups (P > 0.05).

CONCLUSIONS

Prophylactic rewarming relieved PONV and improved the quality of postoperative recovery.

CHINESE CLINICAL TRIAL REGISTER (CHICTR)

ChiCTR-IOR-17012901.

Management strategies for the treatment and prevention of postoperative/postdischarge nausea and vomiting: an updated review

Postoperative nausea and vomiting (PONV) and postdischarge nausea and vomiting (PDNV) remain common and distressing complications following surgery. The routine use of opioid analgesics for perioperative pain management is a major contributing factor to both PONV and PDNV after surgery. PONV and PDNV can delay discharge from the hospital or surgicenter, delay the return to normal activities of daily living after discharge home, and increase medical costs. The high incidence of PONV and PDNV has persisted despite the introduction of many new antiemetic drugs (and more aggressive use of antiemetic prophylaxis) over the last two decades as a result of growth in minimally invasive ambulatory surgery and the increased emphasis on earlier mobilization and discharge after both minor and major surgical procedures (e.g. enhanced recovery protocols). Pharmacologic management of PONV should be tailored to the patient’s risk level using the validated PONV and PDNV risk-scoring systems to encourage cost-effective practices and minimize the potential for adverse side effects due to drug interactions in the perioperative period. A combination of prophylactic antiemetic drugs with different mechanisms of action should be administered to patients with moderate to high risk of developing PONV. In addition to utilizing prophylactic antiemetic drugs, the management of perioperative pain using opioid-sparing multimodal analgesic techniques is critically important for achieving an enhanced recovery after surgery. In conclusion, the utilization of strategies to reduce the baseline risk of PONV (e.g. adequate hydration and the use of nonpharmacologic antiemetic and opioid-sparing analgesic techniques) and implementing multimodal antiemetic and analgesic regimens will reduce the likelihood of patients developing PONV and PDNV after surgery.

Metoclopramide, Dexamethasone, or Palonosetron for Prevention of Delayed Chemotherapy-Induced Nausea and Vomiting After Moderately Emetogenic Chemotherapy (MEDEA): A Randomized, Phase III, Noninferiority Trial

BACKGROUND

For the prevention of chemotherapy-induced nausea and vomiting (CINV) during the delayed phase (24-120 hours) after moderately emetogenic chemotherapy (MEC), the use of 3-day dexamethasone (DEX) is often recommended. This study compared the efficacy and safety of two DEX-sparing regimens with 3-day DEX, focusing on delayed nausea.

PATIENTS AND METHODS

This open-label, randomized, phase III study was designed to demonstrate noninferiority of two DEX-sparing regimens: ondansetron + DEX on day 1 + metoclopramide on days 2-3 (MCP arm), and palonosetron + DEX on day 1 (PAL arm) versus ondansetron on day 1 + DEX on days 1-3 (DEX arm) in chemotherapy-naïve patients receiving MEC. Primary efficacy endpoint was total control (TC; no emetic episodes, no use of rescue medication, no nausea) in the delayed phase. Noninferiority was defined as a lower 95% CI greater than the noninferiority margin set at -20%. Secondary endpoints included no vomiting, no rescue medication, no (significant) nausea, impact of CINV on quality of life, and antiemetics-associated side effects.

RESULTS

Treatment arms were comparable for 189 patients analyzed: predominantly male (55.7%), median age 65.0 years, colorectal cancer (85.7%), and oxaliplatin-based chemotherapy (81.5%). MCP demonstrated noninferiority to DEX for delayed TC (MCP 56.1% vs. DEX 50.0%; 95% CI, -11.3%, 23.5%). PAL also demonstrated noninferiority to DEX (PAL 55.6% vs. DEX 50.0%; 95% CI, -12.0%, 23.2%). There were no statistically significant differences for all secondary endpoints between treatment arms.

CONCLUSION

This study showed that DEX-sparing regimens are noninferior to multiple-day DEX in terms of delayed TC rate in patients undergoing MEC. ClinicalTrials.gov identifier. NCT02135510.

IMPLICATIONS FOR PRACTICE

Chemotherapy-induced nausea and vomiting (CINV) in the delayed phase (24-120 hours after chemotherapy) remains one of the most troublesome adverse effects associated with cancer treatment. In particular, delayed nausea is often poorly controlled. The role of dexamethasone (DEX) in the prevention of delayed nausea after moderately emetogenic chemotherapy (MEC) is controversial. This study is the first to include nausea assessment as a part of the primary study outcome to better gauge the effectiveness of CINV control and patients' experience. Results show that a DEX-sparing strategy does not result in any significant loss of overall antiemetic control: DEX-sparing strategies incorporating palonosetron or multiple-day metoclopramide are safe and at least as effective as standard treatment with a 3-day DEX regimen with ondansetron in controlling delayed CINV-and nausea in particular-following MEC.

"My Body Hates Me": A Qualitative Analysis of the Experience of Functional Nausea in Adolescent Girls and Their Mothers

Nausea is a somatic sensation typically associated with the need to vomit in order to remove a toxin from the body. When nausea occurs in the absence of a specific structural cause or toxin, it is classified as a functional gastrointestinal disorder (FGID). Functional nausea was newly recognized in 2016 as a FGID in children and little is known about its prevalence, course or patient experiences. Nausea co-occurring with functional abdominal pain in childhood has been associated with long-term risk for anxiety and ongoing somatic symptoms into young adulthood. However, few studies have focused uniquely on the experience and impact of nausea on youth. The present study aimed to qualitatively understand the experiences of adolescent girls with functional nausea and their parents. Five mother-daughter dyads were recruited from a specialized pediatric gastroenterology clinic focused on nausea and completed semi-structured interviews. Interviews were transcribed and coded using interpretive phenomenological analysis (IPA). Four main themes emerged: nausea interference, body frustration, misunderstanding of symptoms, and maternal helplessness and guilt. These themes were similar to prior studies on the experiences of youth with chronic pain but also indicated unique challenges due to nausea, such as significant food restriction and subsequent weight loss.

Cannabis use is associated with a small increase in the risk of postoperative nausea and vomiting: a retrospective machine-learning causal analysis

BACKGROUND

Cannabis legalization may contribute to an increased frequency of chronic use among patients presenting for surgery. At present, it is unknown whether chronic cannabis use modifies the risk of postoperative nausea and vomiting (PONV).

METHODS

This study was a retrospective cohort study conducted at 2 academic medical centers. Twenty-seven thousand three hundred eighty-eight adult ASA 1-3 patients having general anesthesia for non-obstetric, non-cardiac procedures and receiving postoperative care in the Post Anesthesia Care Unit (PACU) were analyzed in the main dataset, and 16,245 patients in the external validation dataset. The main predictor was patient reported use of cannabis in any form collected during pre-anesthesia evaluation and recorded in the chart. The primary outcome was documented PONV of any severity prior to PACU discharge, including administration of rescue medications in PACU. Relevant clinical covariates (risk factors for PONV, surgical characteristics, administered prophylactic antiemetic drugs) were also recorded.

RESULTS

10.0% of patients in the analytic dataset endorsed chronic cannabis use. Using Bayesian Additive Regression Trees (BART), we estimated that the relative risk for PONV associated with daily cannabis use was 1.19 (95 CI% 1.00-1.45). The absolute marginal increase in risk of PONV associated with daily cannabis use was 3.3% (95% CI 0.4-6.4%). We observed a lesser association between current, non-daily use of cannabis (RR 1.07, 95% CI 0.94-1.21). An internal validation analysis conducted using propensity score adjustment and Bayesian logistic modeling indicated a similar size and magnitude of the association between cannabis use and PONV (OR 1.15, 90% CI 0.98-1.33). As an external validation, we used data from another hospital in our care system to create an independent model that demonstrated essentially identical associations between cannabis use and PONV.

CONCLUSIONS

Cannabis use is associated with an increased relative risk and a small increase in the marginal probability of PONV.

Antiemetics: types, actions and uses

Nausea and vomiting are common symptoms in the hospital setting, with numerous causes. Common precipitants leading to or complicating inpatient hospital admissions include nausea and vomiting secondary to drugs, gastrointestinal disturbances, metabolic aberrancies, and vestibular pathologies. Appropriate selection and prescribing of antiemetic drugs is therefore important for healthcare professionals. There are numerous antiemetics available to physicians, ranging from muscarinic, dopaminergic and serotoninergic drugs, each acting on a different part of the nausea-vomiting cascade. This review describes the main pathophysiological processes involved in the development of symptomatic nausea and vomiting, and gives an overview of how common antiemetic drugs function to alleviate symptoms, alongside cautions and contraindications in their usage.

Management of Gastrointestinal Symptoms (Nausea, Anorexia and Cachexia, Constipation) in Advanced Illness

Anorexia and cachexia, nausea and vomiting, and constipation are gastrointestinal symptoms that commonly accompany serious illness. Basic science and clinical research continue to improve the understanding of their pathophysiology. Thorough assessment necessitates history, physical examination, and laboratory and diagnostic testing. Pharmacologic management attempts to counteract or reverse the underlying pathophysiologic mechanisms that accompany each symptom, which may benefit from a multimodal approach to achieve adequate control. Future improvements in management require investments in clinical research to determine the efficacy of novel agents along with comparator studies to better understand which treatments should be used in what sequence or combination.

Transversus Abdominis Plane Block versus Wound Infiltration with Conventional Local Anesthetics in Adult Patients Underwent Surgery: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Background

How to effectively control the postoperative pain of patients is extremely important to clinicians. Transversus abdominis plane (TAP) block is a novel analgesic method reported to greatly decrease postoperative pain. However, in many areas, there still exists a phenomenon of surgeons using wound infiltration (WI) with conventional local anesthetics (not liposome anesthetics) as the main means to decrease postoperative pain because of traditional wisdom or convenience. Here, we compared the analgesic effectiveness of the two different methods to determine which method is more suitable for adult patients. Materials and methods. A systematic review and meta-analysis of randomized controlled trials (RCTs) comparing TAP block and WI without liposome anesthetics in adult patients were performed. Frequently used databases were extensively searched. The main outcomes were postoperative pain scores in different situations (at rest or during movement) and the time until the first use of rescue analgesics. The secondary outcomes were postoperative nausea and vomiting (PONV) incidence and patient satisfaction scores.

Results

Fifteen studies with 983 participants met the inclusion criteria and were included in the present study. The heterogeneity in the final analysis regarding the pain score was low to moderate. The major results of the sensitivity analysis were stable. WI had the same analgesic effect as TAP block only at the one-hour postoperative time point (mean difference = -0.32, 95% confidence interval (-0.87, 0.24), P = 0.26) and was associated with a shorter time until the first rescue analgesic and poorer patient satisfaction.

Conclusion

TAP block results in a more effective and steady analgesic effect than WI with conventional local anesthetics in adult patients from the early postoperative period and obtains higher patient satisfaction.

Status of Brain Imaging in Gastroparesis

The pathophysiology of nausea and vomiting in gastroparesis is complicated and multifaceted involving the collaboration of both the peripheral and central nervous systems. Most treatment strategies and studies performed in gastroparesis have focused largely on the peripheral effects of this disease, while our understanding of the central nervous system mechanisms of nausea in this entity is still evolving. The ability to view the brain with different neuroimaging techniques has enabled significant advances in our understanding of the central emetic reflex response. However, not enough studies have been performed to further explore the brain–gut mechanisms involved in nausea and vomiting in patients with gastroparesis. The purpose of this review article is to assess the current status of brain imaging and summarize the theories about our present understanding on the central mechanisms involved in nausea and vomiting (N/V) in patients with gastroparesis. Gaining a better understanding of the complex brain circuits involved in the pathogenesis of gastroparesis will allow for the development of better antiemetic prophylactic and treatment strategies.

Chemistry and Effects of Brainstem Acting Drugs

BACKGROUND

Brain is the most sensitive organ, whereas brainstem is the most important part of Central Nervous System (CNS). It connects the brain and the spinal cord. However, a myriad of drugs and chemicals affects CNS with severe resultant effects on the brainstem.

METHODS

In view of this, a number of literature were assessed for information on the most sensitive part of brain, drugs and chemicals that act on the brainstem and clinical benefit and risk assessment of such drugs and chemicals.

RESULTS

Findings have shown that brainstem regulates heartbeat, respiration and because it connects the brain and spinal cord, all the drugs that act on the spinal cord may overall affect the systems controlled by the spinal cord and brain. The message is sent and received by temporal lobe, occipital lobe, frontal lobe, parietal lobe and cerebellum.

CONCLUSION

Hence, the chemical functional groups of the brainstem and drugs acting on brainstem are complementary, and may produce either stimulation or depression of CNS.

Antiemetic drugs: what to prescribe and when

Nausea and vomiting are common symptoms with many possible causes, including the adverse effects of drugs. If a drug is indicated, the cause guides the choice of antiemetic drug The main antiemetic classes include antagonists of the serotonin, dopamine, histamine, muscarinic and neurokinin systems, corticosteroids and benzodiazepines. Some antiemetics appear more effective for specific indications Serotonin and neurokinin antagonists, such as ondansetron and aprepitant, are highly effective in treating chemotherapy-induced nausea and vomiting. Metoclopramide and antihistamines are first-line options for nausea and vomiting in pregnancy Serotonin antagonists and some dopamine antagonists, such as metoclopramide, can prolong the QT interval on the ECG. Dopamine antagonists can cause extrapyramidal adverse effects, particularly in children

Longitudinal gray matter changes of the pain matrix in patients with carbon monoxide intoxication: A voxel-based morphometry study

PURPOSE

Carbon monoxide (CO) intoxication causes gray matter (GM) changes and headache symptom in patients with CO intoxication, but the headache-associated GM changes are not well understood. The purpose of this study was to perform a voxel-based morphometry (VBM) analysis to investigate longitudinal GM changes of brain pain matrix in patients with CO intoxication.

METHODS

This prospective study enrolled 24 patients with CO intoxication and 20 healthy controls. Whole brain high-resolution T1-weighted images were acquired in both groups and were repeated in patients at 1 week, and 1, 3, and 9 months after CO exposure. VBM was performed to detect global GM changes in patients with CO intoxication, and the automated anatomical labeling template was utilized to estimate the distribution of significant GM clusters in the brain.

RESULTS

GM volumes were significantly decreased mainly in the frontal and occipital lobes, including several pain-matrix regions 1 week after CO intoxication. The regions with significant GM changes further involved the central GM structures and the periaqueductal gray (pain-modulating center) at 1 and 3 months after CO intoxication, but the alterations were partially normalized in the frontal lobe and cerebellum 9 months after CO intoxication. Significant negative correlations were revealed between GM volume and duration of coma in the pain matrix regions. Moreover, five patients exhibited delayed neuropsychiatric sequelae (DNS) and had greater GM volume changes than non-DNS patients.

CONCLUSION

VBM analysis is helpful to understand the longitudinal GM changes of the pain matrix in patients with CO intoxication.

Nausea and Vomiting: a Palliative Care Imperative

PURPOSE OF REVIEW

This review was undertaken to survey recent literature for research reports and comprehensive clinical reviews addressing the pharmacologic management of nausea and vomiting (N&V) in advanced cancer. The goal was to integrate findings in a comprehensive article that incorporates palliative care concepts into antiemetic treatment.

RECENT FINDINGS

There are few published studies of N&V in advanced cancer; such research may be limited by the multicausal nature of N&V and participant burden to patients with life-limiting disease. Most articles are written by oncologists who also specialize in palliative care, and those addressing adverse effects of drugs used as antiemetics are found in other literature. Articles addressing more novel therapies, like cannabinoids and medical marijuana, are uncommon in the oncology literature. N&V in patients with progressive or advanced cancer is often multicausal. Nausea is more common and persistent, and even mild nausea is bothersome and may cause anxiety or depression. The mechanisms of nausea and vomiting overlap, but different neural pathways constitute the final pathway for each-the brainstem for vomiting and higher brain regions for nausea. Common causes of N&V in advanced cancer include constipation, opioids, and malignant bowel obstruction. About 40% have undetermined causes and may be exacerbated by impaired gastric emptying, chemical imbalances, or other factors. Several drugs that have antiemetic effects and act at different receptors are used to palliate N&V. There is a paucity of research that supports palliative antiemetic choices, and other research is needed to define potential therapeutic strategies that capitalize on differences between nausea and vomiting.

Do Asian and North American patients with bipolar disorder have similar efficacy, tolerability, and safety profile during clinical trials with atypical antipsychotics?

BACKGROUND

The approvals of psychotropics for bipolar disorder (BD) are mainly based on randomized, double-blind, placebo-controlled trials (RCTs) from North America. It remains unknown whether approved psychotropics have similar efficacy, tolerability, and safety for Asians with BD. The aim of this systematic review was to compare those differences of psychotropics between Asians and North Americans with BD.

METHODS

MEDLINE, EMBASE, and PsycINFO were searched for RCTs studied in two regions. The effect size, remission/response rate, and risk for discontinuation due to adverse events (AEs), weight gain (WG), nervous systems and gastrointestinal AEs were assessed and compared between two regions with Cohen's d or number needed to treat/harm.

RESULTS

Eleven studies of aripiprazole, olanzapine, risperidone, and quetiapine in BD were included. Similar efficacy and relatively benign tolerability of atypical antipsychotics (AAPs) between Asians and Americans with BD were observed in most studies. The risk for AAP-related WG was similar between two regions. Asians with mania or bipolar depression were more vulnerable to akathisia/tremor or constipation. Japanese and Chinese with bipolar depression were more sensitive to somnolence and dizziness, respectively. Americans were more likely to have dry mouth, nausea, and vomiting.

LIMITATIONS

The number of included psychotropics and papers was small.

CONCLUSIONS

Differences in AAP-related efficacy and tolerability were minimal between the two regions, but some AEs appeared to be different. Clinicians should pay attention to these differences to optimize treatment strategies in different races/ethnicities with BD.

Adding dexmedetomidine to morphine-based analgesia reduces early postoperative nausea in patients undergoing gynecological laparoscopic surgery: a randomized controlled trial

BACKGROUND

Few studies have investigated the effect of dexmedetomidine on postoperative nausea and vomiting (PONV) in patients underwent gynecological laparoscopic surgery. We investigated if adding dexmedetomidine to a morphine-based patient-controlled analgesia (PCA) could decrease the incidence of PONV in this high-risk patient population.

METHODS

In this prospective, randomized, double-blind and placebo-controlled study, 122 patients underwent gynecological laparoscopic surgery were assigned into two groups. Patients in the dexmedetomidine group (Group Dex) received a loading dose of dexmedetomidine 0.4 μg/kg before the end of surgery, followed by morphine 0.5 mg/ml plus dexmedetomidine 1 μg/ml for postoperative i.v. PCA. Patients in the control group (Group Ctrl) received normal saline before the end of surgery, followed by morphine 0.5 mg/ml alone for postoperative i.v. PCA. PCA pump was programmed as followed: bolus dose 2 ml, lockout interval 8 min and background infusion at a rate of 1 ml/h. The primary outcome was the incidence of nausea and vomiting within the first postoperative 24 h.

RESULTS

Although there were no significant differences in regard to the total incidence of PONV (41.0% vs 52.5%, P = 0.204), PONV score, time to first onset of PONV, or the need for rescue antiemetics within the first postoperative 24 h between the two groups, the incidence of nausea and total PONV during the first 2 h period was significantly lower in the Group Dex than in the Group Ctrl (9.8% vs 24.6%, P = 0.031 and 0.031, respectively). More patients in Group Dex were over sedated or had bradycardia during the PACU compared with Group Ctrl (P = 0.040 and 0.036, respectively).

CONCLUSION

Our protocol in which dexmedetomidine was administered postoperatively - after a loading dose - to intravenous PCA morphine in patients undergoing gynecological laparoscopic surgery, had only early antiemetic effects, while no clinically meaningful antiemetic effect could be evidenced within the first 24 h after surgery.

TRIAL REGISTRATION

Current control trial registered at Chictr.org.cn: ChiCTR1800017172. Date registered: 07/16/2018.

Role of lactic acidosis as a mediator of sprint-mediated nausea

This study aims to determine whether there is a relationship between nausea level and lactic acidosis during recovery from sprinting. In all, 13 recreationally active males completed a 60 s bout of maximal intensity cycling. Prior to and for 45 min following exercise, blood pH, pCO2 , and lactate levels were measured together with nausea. In response to sprinting, nausea, lactate, and H+ concentrations increased and remained elevated for at least 10 min (p < .001), whereas pCO2 increased only transiently (p < .001) before falling below pre-exercise levels (p < .001), with all these variables returning toward pre-exercise levels during recovery. Both measures of nausea adopted for analyses (nausea profile, NP; visual analogue scale, VAS), demonstrated significant repeated measures correlation (rmcorr) post-exercise between nausea and plasma lactate (VAS and NPrrm > 0.595, p < .0001) and H+ concentrations (VAS and NPrrm > 0.689, p < .0001), but an inconsistent relationship with pCO2 (VAS rrm  = 0.250, p = .040; NP rrm  = 0.144, p = .248) and bicarbonate levels (VAS rrm  = -0.252, p = .095; NP rrm  = -0.397, p = .008). Linear mixed modeling was used to predict the trajectory of nausea over time, with both lactate and H+ concentrations found to be key predictors of nausea (p < .0001). In conclusion, this study reveals a strong positive relationship between nausea and both H+ and lactate concentrations during recovery from sprinting, a finding consistent with H+ and lactate being potential mediators of nausea post-sprinting. However, as the timing of the recovery of both H+ and lactate was delayed, compared to that of nausea, further research is required to confirm these findings and investigate other potential mechanisms.

Revisiting the physiology of nausea and vomiting-challenging the paradigm

PURPOSE

The predominant neurotransmitters and receptors for acute and delayed chemotherapy-induced nausea and vomiting (CINV) are represented in the current paradigm, which reflects successful control of emesis. However, control of nausea (N) lags behind management of vomiting (V). This review aims to re-examine and incorporate new information about the mechanisms of V and N.

METHODS

The initial literature search focused on CINV. Keywords in articles led to subsequent discovery of publications focused on N&V in other medical and scientific fields (e.g., gastroenterology, neurology, cannabinoid science, neuropharmacology, and motion sickness). Using keywords to identify other sources continued until no further recent, meaningful publications were found.

RESULTS

More than 86% of references were from recent non-oncology journals and books, suggesting there are many areas for cross-fertilization research into mechanisms and management of N&V-particularly of N, which involves overlapping and dissimilar CNS areas from V. Information from cited articles was incorporated into visual representation of N&V, which is certainly not exhaustive but supports highly complex processes in the stomach and gut, the vagus nerve and spinal cord neurons, the nucleus tractus solitarii, and the anterior insular cortex and anterior cingulate cortex with input from the amygdala.

CONCLUSIONS

These data support the idea that mechanisms for N, whatever the cause, must be highly similar. Continued research into nausea, including patient-reported evaluation and outcomes, is important; interventions for nausea could be considered adjuvants to current standard of care antiemetics and be individualized, depending on patient-reported efficacy and adverse effects and preferences.

Comparison of common side effects from mood stabilizers and antipsychotics between pediatric and adult patients with bipolar disorder: a systematic review of randomized, double-blind, placebo-controlled trials

INTRODUCTION

To compare common side effects of mood stabilizers (MSs) and antipsychotics in pediatric and adult bipolar disorder (BD).

AREAS COVERED

MEDLINE, EMBASE, PsycINFO was searched for randomized, double-blind, placebo-controlled trials (RCTs) in the treatment of pediatric and adult BD. Twelve RCTs for pediatric patients and 30 for adult patients were included. The risk for the discontinuation due to adverse events, ≥7% weight gain, somnolence, akathisia, nausea and vomiting from a medication relative to placebo was estimated with absolute risk increase and the number needed to harm. The relative risk of these measures in pediatric and adult patients was compared.

EXPERT OPINION

Overall, the relative risk for ≥7% weight gain, somnolence, nausea, or vomiting was higher, and akathisia was lower in pediatric patients than in adults. The magnitude of difference among MSs and antipsychotics and between pediatrics and adults varied widely. The risk for pediatric patients could be underestimated because in most pediatric studies, doses of studied medications were lower and flexibly dosed, and titration speeds were slower than in adult studies. Clinicians should pay attention to differences in study designs to understand the risk for common side effects when prescribing a medication for BD.

Risk factors for chemotherapy-induced nausea in pediatric patients receiving highly emetogenic chemotherapy

BACKGROUND

Little is known regarding risk factors for chemotherapy-induced nausea (CIN) in pediatric patients.

PROCEDURE

A secondary analysis was conducted of a previously published multicenter, prospective, randomized, single-blind, sham-controlled trial assessing the efficacy of acupressure in preventing CIN in pediatric patients receiving highly emetogenic chemotherapy. The primary outcome was nausea severity, self-reported using the Pediatric Nausea Assessment Tool. The relationships between acute and delayed nausea severity and patient- (sex, race, age, and cancer diagnosis) and treatment-related (chemotherapy, antiemetic prophylaxis, CIN, and vomiting control) factors were analyzed by a proportional odds generalized estimating equation approach. The acute phase started with administration of the first and continued for 24 hours after the last chemotherapy dose. The delayed phase started at the end of the acute phase and continued until the next chemotherapy block (maximum seven days).

RESULTS

In the acute and delayed phases, 165 and 144 patients provided data for analysis, respectively. Nonwhite race was significantly associated with higher acute phase nausea severity (OR, 1.7; 95% CI, 1.1-2.6). Poor CIN control in the acute phase (OR, 16; 95% CI, 4.0-64.6), diagnosis of a cancer other than a central nervous system (CNS) tumor (OR, 2.5; 95% CI, 1.2-5.3), and cisplatin administration (OR, 3.7; 95% CI, 2.1-6.0) were significantly associated with higher delayed phase nausea severity.

CONCLUSION

Acute phase CIN was associated with nonwhite race. Delayed phase CIN was associated with poor acute phase CIN control, diagnosis of non-CNS cancer, and receipt of cisplatin. These findings will inform future antiemetic trial design.

Functional brain networks and neuroanatomy underpinning nausea severity can predict nausea susceptibility using machine learning

KEY POINTS

Nausea is an adverse experience characterised by alterations in autonomic and cerebral function. Susceptibility to nausea is difficult to predict, but machine learning has yet to be applied to this field of study. The severity of nausea that individuals experience is related to the underlying morphology (shape) of the subcortex, namely of the amygdala, caudate and putamen; a functional brain network related to nausea severity was identified, which included the thalamus, cingulate cortices (anterior, mid- and posterior), caudate nucleus and nucleus accumbens. Sympathetic nervous system function and sympathovagal balance, by heart rate variability, was closely related to both this nausea-associated anatomical variation and the functional connectivity network, and machine learning accurately predicted susceptibility or resistance to nausea. These novel anatomical and functional brain biomarkers for nausea severity may permit objective identification of individuals susceptible to nausea, using artificial intelligence/machine learning; brain data may be useful to identify individuals more susceptible to nausea.

ABSTRACT

Nausea is a highly individual and variable experience. The central processing of nausea remains poorly understood, although numerous influential factors have been proposed, including brain structure and function, as well as autonomic nervous system (ANS) activity. We investigated the role of these factors in nausea severity and if susceptibility to nausea could be predicted using machine learning. Twenty-eight healthy participants (15 males; mean age 24 years) underwent quantification of resting sympathetic and parasympathetic nervous system activity by heart rate variability. All were exposed to a 10-min motion-sickness video during fMRI. Neuroanatomical shape differences of the subcortex and functional brain networks associated with the severity of nausea were investigated. A machine learning neural network was trained to predict nausea susceptibility, or resistance, using resting ANS data and detected brain features. Increasing nausea scores positively correlated with shape variation of the left amygdala, right caudate and bilateral putamen (corrected P = 0.05). A functional brain network linked to increasing nausea severity was identified implicating the thalamus, anterior, middle and posterior cingulate cortices, caudate nucleus and nucleus accumbens (corrected P = 0.043). Both neuroanatomical differences and the functional nausea-brain network were closely related to sympathetic nervous system activity. Using these data, a machine learning model predicted susceptibility to nausea with an overall accuracy of 82.1%. Nausea severity relates to underlying subcortical morphology and a functional brain network; both measures are potential biomarkers in trials of anti-nausea therapies. The use of machine learning should be further investigated as an objective means to develop models predicting nausea susceptibility.

Practical Perspectives in the Treatment of Nausea and Vomiting

Nausea and vomiting result from complex interactions between afferent and efferent pathways of the gastrointestinal tract, central nervous system, and autonomic nervous system. Afferent pathways from the vagus nerve, vestibular system, and chemoreceptor trigger zone project to nucleus tractus solitarius, which in turn relays signals to the central pattern generator to initiate multiple downstream pathways resulting in symptoms of nausea and vomiting. There is increasing evidence that the central pathway of chronic nausea is different from that of acute nausea and vomiting-and closely resembles that of neuropathic pain. This improved understanding of chronic nausea has resulted in a paradigm shift with regard to management strategy. Although conventional therapies such as antiemetics and prokinetics are commonly used to manage acute nausea and vomiting, they are historically not as effective in treating chronic nausea. Recently, neuromodulator agents, such as tricyclic antidepressants, gabapentin, olanzapine, mirtazapine, and benzodiazepines, and cannabinoids have been shown to be efficacious in the treatment of nausea and vomiting, and may be useful in the treatment of chronic symptoms. There is a need to study these agents, especially in the management of chronic functional nausea. Improved understanding of the central and peripheral circuitry of nausea and vomiting symptoms will allow for enhanced utilization of the currently available medications, and the development of novel therapeutic options.

Molecular mechanisms for nicotine intoxication

Nicotine, one of the more than 4700 ingredients in tobacco smoke, is a neurotoxin and once used as pesticides in agriculture. Although its use in agriculture is prohibited in many countries, nicotine intoxication is still a problem among the workers in tobacco farms, and young children as well as adults due to the accidental or suicidal ingestions of nicotine products. Understanding the mechanism of nicotine intoxication is important not only for the prevention and treatment but also for the appropriate regulatory approaches. Here, we review pharmacokinetics of nicotine and the molecular mechanisms for acute and chronic intoxication from nicotine that might be relevant to the central and the peripheral nervous system. We include green tobacco sickness, acute intoxication from popular nicotine products, circadian rhythm changes, chronic intoxication from nicotine through prenatal nicotine exposure, newborn behaviors, and sudden infant death syndrome.

Pharmacological treatments for functional nausea and functional dyspepsia in children: a systematic review

INTRODUCTION

Chronic idiopathic nausea (CIN) and functional dyspepsia (FD) cause considerable strain on many children's lives and their families. Areas covered: This study aims to systematically assess the evidence on efficacy and safety of pharmacological treatments for CIN or FD in children. CENTRAL, EMBASE, and Medline were searched for Randomized Controlled Trials (RCTs) investigating pharmacological treatments of CIN and FD in children (4-18 years). Cochrane risk of bias tool was used to assess methodological quality of the included articles. Expert commentary: Three RCTs (256 children with FD, 2-16 years) were included. No studies were found for CIN. All studies showed considerable risk of bias, therefore results should be interpreted with caution. Compared with baseline, successful relief of dyspeptic symptoms was found for omeprazole (53.8%), famotidine (44.4%), ranitidine (43.2%) and cimetidine (21.6%) (p = 0.024). Compared with placebo, famotidine showed benefit in global symptom improvement (OR 11.0; 95% CI 1.6-75.5; p = 0.02). Compared with baseline, mosapride versus pantoprazole reduced global symptoms (p = 0.011; p = 0.009). One study reported no occurrence of adverse events. This systematic review found no evidence to support the use of pharmacological drugs to treat CIN or FD in children. More high-quality clinical trials are needed.

ABBREVIATIONS

AP-FGID: Abdominal Pain Related Functional Gastrointestinal Disorders; BART: Biofeedback-Assisted Relaxation Training; CIN: Chronic Idiopathic Nausea; COS: Core Outcomes Sets; EPS: Epigastric Pain Syndrome; ESPGHAN: European Society for Pediatric Gastroenterology Hepatology and Nutrition; FAP: Functional Abdominal Pain; FD: Functional Dyspepsia; GERD: Gastroesophageal Reflux Disease; GES: Gastric Electrical Stimulation; H2RAs: H2 Receptor Antagonists; IBS: irritable bowel syndrome; NASPGHAN: North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition; PDS: Postprandial Distress Syndrome; PPIs: Proton Pump Inhibitor; PROMs: Patient Reported Outcome Measures; RCTs: Randomized Controlled Trials; SSRIs: selective serotonin reuptake inhibitors; TCAs: tricyclic antidepressants.

The Neurophysiology and Treatment of Motion Sickness

BACKGROUND

Seasickness and travel sickness are classic types of motion illness. Modern simulation systems and virtual reality representations can also induce comparable symptoms. Such manifestations can be alleviated or prevented by various measures.

METHODS

This review is based on pertinent publications retrieved by a PubMed search, with special attention to clinical trials and review articles.

RESULTS

Individuals vary in their susceptibility to autonomic symptoms, ranging from fatigue to massive vomiting, induced by passive movement at relatively low frequencies (0.2 to 0.4 Hz) in situations without any visual reference to the horizontal plane. Younger persons and women are considered more susceptible, and twin studies have revealed a genetic component as well. The various types of motion sickness are adequately explained by the intersensory conflict model, incorporating the vestibular, visual, and proprioceptive systems and extended to include consideration of postural instability and asymmetry of the otolith organs. Scopolamine and H1-antihistamines, such as dimenhydrinate and cinnarizine, can be used as pharmacotherapy. The symptoms can also be alleviated by habituation through long exposure or by the diminution of vestibular stimuli.

CONCLUSION

The various types of motion sickness can be treated with general measures to lessen the intersensory conflict, behavioral changes, and drugs.

Endocannabinoids in Body Weight Control

Maintenance of body weight is fundamental to maintain one's health and to promote longevity. Nevertheless, it appears that the global obesity epidemic is still constantly increasing. Endocannabinoids (eCBs) are lipid messengers that are involved in overall body weight control by interfering with manifold central and peripheral regulatory circuits that orchestrate energy homeostasis. Initially, blocking of eCB signaling by first generation cannabinoid type 1 receptor (CB1) inverse agonists such as rimonabant revealed body weight-reducing effects in laboratory animals and men. Unfortunately, rimonabant also induced severe psychiatric side effects. At this point, it became clear that future cannabinoid research has to decipher more precisely the underlying central and peripheral mechanisms behind eCB-driven control of feeding behavior and whole body energy metabolism. Here, we will summarize the most recent advances in understanding how central eCBs interfere with circuits in the brain that control food intake and energy expenditure. Next, we will focus on how peripheral eCBs affect food digestion, nutrient transformation and energy expenditure by interfering with signaling cascades in the gastrointestinal tract, liver, pancreas, fat depots and endocrine glands. To finally outline the safe future potential of cannabinoids as medicines, our overall goal is to address the molecular, cellular and pharmacological logic behind central and peripheral eCB-mediated body weight control, and to figure out how these precise mechanistic insights are currently transferred into the development of next generation cannabinoid medicines displaying clearly improved safety profiles, such as significantly reduced side effects.

Hyperirritable stomach as a cause of obstructive symptoms after sleeve gastrectomy: clinical and radiographic findings

PURPOSE

To characterize clinical and radiographic features of a hyperirritable stomach after sleeve gastrectomy.

MATERIALS/METHODS

Radiology reports revealed that 10/76 patients (13%) with obstructive symptoms after sleeve gastrectomy had a hyperirritable stomach.

RESULTS

All 10 patients presented with nausea, vomiting, and/or regurgitation. All 10 had emesis on barium studies in the absence of gastric outlet obstruction, gastroparesis, or small bowel obstruction/ileus. Five had extraintestinal causes of nausea/vomiting. Eight had improvement/resolution of symptoms on medical treatment.

CONCLUSION

In 13% of patients with nausea/vomiting after sleeve gastrectomy, barium studies revealed a hyperirritable stomach, which likely is multifactorial and self-limited in most patients.

Antiemetic Use in the Emergency Department

Nausea and vomiting are 2 of the most common complaints of patients presenting to the emergency department (ED). In addition, antiemetics are the most commonly prescribed medications in the ED behind analgesics. Treating these conditions can be complex, especially as one considers that nausea and/or vomiting could be the primary presenting illness or simply a symptom of a more complex etiology. Although there is a wide variety of pharmacotherapeutic options in the armamentarium to treat these conditions, very few consensus recommendations exist to help guide the use of antiemetic agents in the ED, leading to wide variability in medication use. Contributing to these variations in practice is the extended spectrum of etiologies and potential physiological factors that contribute to the development of nausea or vomiting. A thorough understanding of the pharmacology and administration of these agents can help practitioners devise tailored antiemetic regimens based upon the underlying etiology.

The Role and Treatment Implications of Peripheral and Central Processing of Pain, Pruritus, and Nausea in Heightened Somatic Awareness: A Review

Pain, pruritus, and nausea are complex sensory and emotional physiological symptoms that can vary widely between people and even within an individual, depending on the context and meaning of the symptom and the psychological state of the person. This article reviews the acute neural transmission of pain, pruritus, and nausea symptoms, which can begin in the periphery and/or viscera. The subsequent multiple pathways in the central nervous system that become involved in the processing of these symptoms are also discussed. The authors describe human brain imaging studies that have revealed consistent cortical and subcortical networks activated by these symptoms, including sensory, limbic, and associative regions. In particular, the authors discuss information revealed by the studies regarding the primary somatosensory cortex, secondary somatosensory cortex, anterior cingulate cortex, insula, prefrontal cortex and thalamus, are the brain areas most commonly activated by noxious stimuli. Finally, the authors describe treatment options for chronic presentations of these symptoms, which are, in part, based on central nervous processing of these sensations.

Central Aspects of Nausea and Vomiting in GI Disorders

OPINION STATEMENT

Nausea and vomiting result from continuous interactions among gastrointestinal, central nervous system, and autonomic nervous system. Despite being closely associated, central pathways of nausea and vomiting appear to be at least partly different and nausea is no longer considered only a penultimate step of vomiting. Although our understanding of central pathways of nausea has improved over the last one decade, it is still very basic. Afferent pathways from gastrointestinal tract via vagus, vestibular system, and chemoreceptor trigger zone project to nucleus tractus solitarius which, in turn, relays the signal to central pattern generator initiating multiple downstream pathways. This central nausea pathway appears to be under constant modulation by autonomic nervous system and cerebral cortex. There is also some evidence that central pathway of chronic nausea is different from that of acute nausea and closely resembles that of neuropathic pain. This improved understanding has modified the way we can approach the treatment of acute and chronic nausea. While conventional therapies such as antiemetics (antiserotoninergic, antihistaminic, antidopaminergic) and prokinetics are commonly used to manage acute nausea, they are not as effective in improving chronic nausea. Recently, neuromodulators such as tricyclic antidepressants, gabapentin, olanzapine, benzodiazepines, and cannabinoids have been shown to have antinausea effect. There is a need to study the utility of these drugs in managing chronic functional nausea. Improving our understanding of central and peripheral circuitry of nausea will allow us to better utilize the currently available drugs and develop new therapeutic options.

A novel treatment for "morning sickness": Nausea of pregnancy could be induced by excess sulfite which molybdenum can help alleviate

Nausea and vomiting of pregnancy (NVP) remains difficult to treat. Last century, thalidomide was used to alleviate NVP, but it caused teratogenesis by interfering with angiogenesis. The gasotransmitters hydrogen sulfide (H2S) and nitric oxide are mutually dependent on each other for their angiogenesis-related functions. Pregnancy-related requirements for increased endogenous H2S could create a temporary excess of sulfite, an H2S catabolite, which is toxic and can induce nausea. Sulfite oxidase, a molybdenum-containing enzyme, catalyzes oxidation of sulfite to sulfate, which can then be excreted or reused by the body. Supplementation with molybdenum should facilitate enhanced sulfite oxidase activity, thus lowering gestationally-elevated sulfite levels in the gastrointestinal tract and easing NVP.

What is nausea? A historical analysis of changing views

The connotation of "nausea" has changed across several millennia. The medical term 'nausea' is derived from the classical Greek terms ναυτια and ναυσια, which designated the signs and symptoms of seasickness. In classical texts, nausea referred to a wide range of perceptions and actions, including lethargy and disengagement, headache (migraine), and anorexia, with an awareness that vomiting was imminent only when the condition was severe. However, some recent articles have limited the definition to the sensations that immediately precede emesis. Defining nausea is complicated by the fact that it has many triggers, and can build-up slowly or rapidly, such that the prodromal signs and symptoms can vary. In particular, disengagement responses referred to as the "sopite syndrome" are typically present only when emetic stimuli are moderately provocative, and do not quickly culminate in vomiting or withdrawing from the triggering event. This review considers how the definition of "nausea" has evolved over time, and summarizes the physiological changes that occur prior to vomiting that may be indicative of nausea. Also described are differences in the perception of nausea, as well as the accompanying physiological responses, that occur with varying stimuli. This information is synthesized to provide an operational definition of nausea.