Inflammatory Biomarkers and Clinical Judgment in the Emergency Diagnosis of Urgent Abdominal Pain

Pathology of pain and its implications for therapeutic interventions

Pain is estimated to affect more than 20% of the global population, imposing incalculable health and economic burdens. Effective pain management is crucial for individuals suffering from pain. However, the current methods for pain assessment and treatment fall short of clinical needs. Benefiting from advances in neuroscience and biotechnology, the neuronal circuits and molecular mechanisms critically involved in pain modulation have been elucidated. These research achievements have incited progress in identifying new diagnostic and therapeutic targets. In this review, we first introduce fundamental knowledge about pain, setting the stage for the subsequent contents. The review next delves into the molecular mechanisms underlying pain disorders, including gene mutation, epigenetic modification, posttranslational modification, inflammasome, signaling pathways and microbiota. To better present a comprehensive view of pain research, two prominent issues, sexual dimorphism and pain comorbidities, are discussed in detail based on current findings. The status quo of pain evaluation and manipulation is summarized. A series of improved and innovative pain management strategies, such as gene therapy, monoclonal antibody, brain-computer interface and microbial intervention, are making strides towards clinical application. We highlight existing limitations and future directions for enhancing the quality of preclinical and clinical research. Efforts to decipher the complexities of pain pathology will be instrumental in translating scientific discoveries into clinical practice, thereby improving pain management from bench to bedside.

Diagnostic accuracy of novel mRNA blood biomarkers of infection to predict outcomes in emergency department patients with undifferentiated abdominal pain

Abdominal pain represents greater than 20% of US Emergency Department (ED) visits due to a wide range of illnesses. There are currently no reliable blood biomarkers to predict serious outcomes in patients with abdominal pain. Our previous studies have identified three mRNA transcripts related to innate immune activation: alkaline phosphatase (ALPL), interleukin-8 receptor-β (IL8RB), and defensin-1 (DEFA1) as promising candidates to detect an intra-abdominal infection. The objective of this study was to evaluate the accuracy of these mRNA biomarkers to predict likely infection, hospitalization and surgery in Emergency Department patients with undifferentiated abdominal pain. We prospectively enrolled Emergency Department patients with undifferentiated abdominal pain who received an abdominal CT scan as part of their evaluation. Clinical outcomes were abstracted from the CT scan and medical records. mRNA biomarker levels were calculated independent of the clinical outcomes and their accuracy was assessed to predict infectious diagnoses, surgery and hospital admission. 89 patients were enrolled; 21 underwent surgery; 47 underwent hospital admission; and, no deaths were observed within 30 days. In identifying which cases were likely infectious, mRNA biomarkers' AUC values were: ALPL, 0.83; DEFA1 0.51; IL8RB, 0.74; and ALPL + IL8RB, 0.79. In predicting which Emergency Department patients would receive surgery, the AUC values were: ALPL, 0.75; DEFA1, 0.58; IL8RB, 0.75; and ALPL + IL8RB, 0.76. In predicting hospital admission, the AUC values were: ALPL, 0.78; DEFA1, 0.52; IL8RB, 0.74; and, ALPL + IL8RB, 0.77. For predicting surgery, ALPL + IL8RB's positive likelihood ratio (LR) was 3.97; negative LR (NLR) was 0.70. For predicting hospital admission, the same marker's positive LR was 2.80 with an NLR of 0.45. Where the primary cause for admission was a potentially infectious disorder, 33 of 34 cases (97%) had positive RNA scores. In a pragmatic, prospective diagnostic accuracy trial in Emergency Department patients with undifferentiated abdominal pain, mRNA biomarkers showed good accuracy to identify patients with potential infection, as well as those needing surgery or hospital admission.

Quantifying inflammation using interleukin-6 for improved phenotyping and risk stratification in acute heart failure

AIMS

Systemic inflammation may be central in the pathophysiology of acute heart failure (AHF). We aimed to assess the possible role of systemic inflammation in the pathophysiology, phenotyping, and risk stratification of patients with AHF.

METHODS AND RESULTS

Using a novel Interleukin-6 immunoassay with unprecedented sensitivity (limit of detection 0.01 ng/L), we quantified systemic inflammation in unselected patients presenting with acute dyspnoea to the emergency department in a multicentre study. One-year mortality was the primary prognostic endpoint. Among 2042 patients, 1026 (50.2%) had an adjudicated diagnosis of AHF, 83.7% of whom had elevated interleukin-6 concentrations (>4.45 ng/L). Interleukin-6 was significantly higher in AHF patients compared to patients with other causes of dyspnoea (11.2 [6.1-26.5] ng/L vs. 9.0 [3.2-32.3] ng/L, p < 0.0005). Elevated interleukin-6 concentrations were independently predicted by increasing N-terminal pro-B-type natriuretic peptide and high-sensitivity cardiac troponin T, as well as the clinical diagnosis of infection. Among the different AHF phenotypes, interleukin-6 concentrations were highest in patients with cardiogenic shock (25.7 [14.0-164.2] ng/L) and lowest in patients with hypertensive AHF (9.3 [4.8-21.6] ng/L, p = 0.001). Inflammation as quantified by interleukin-6 was a strong and independent predictor of 1-year mortality both in all AHF patients, as well as those without clinically overt infection at presentation (adjusted hazard ratio [95% confidence interval] 1.45 [1.15-1.83] vs. 1.48 [1.09-2.00]). The addition of interleukin-6 significantly improved the discrimination of the BIOSTAT-CHF risk score.

CONCLUSION

An unexpectedly high percentage of patients with AHF have subclinical systemic inflammation as quantified by interleukin-6, which seems to contribute to AHF phenotype and to the risk of death.

Efficacy of electroacupuncture combined with intravenous patient-controlled analgesia after cesarean delivery: a randomized clinical trial

BACKGROUND

Electroacupuncture is a nonpharmacologic intervention for analgesia that is widely recognized as therapy for pain. However, the clinical efficacy of electroacupuncture combined with patient-controlled intravenous analgesia for postoperative analgesia after cesarean delivery remains unclear.

OBJECTIVE

This study aimed to assess the efficacy of electroacupuncture + patient-controlled intravenous analgesia for postoperative analgesia after cesarean delivery, determine the optimal frequency for the best analgesic effect, and explore the underlying mechanism of action.

STUDY DESIGN

This single-center, randomized, single-blinded, sham acupuncture controlled clinical trial was conducted at a tertiary university hospital in China. Female patients who underwent cesarean delivery and received fentanyl as patient-controlled intravenous analgesia for postoperative analgesia were enrolled. Patients were after surgery randomized to receive 2 Hz electroacupuncture treatment (n=53), 20/100 Hz electroacupuncture treatment (n=53), or sham electroacupuncture treatment (n=52) (controls). The 2 electroacupuncture groups received electroacupuncture treatment at 2 or 20/100 Hz at the ST36 and SP6 points, whereas, in the sham electroacupuncture group, sham electroacupuncture was performed at nonmeridian points with nonenergized electroacupuncture instruments. Of note, 4 electroacupuncture treatments were performed in all groups at 6, 12, 24, and 48 hours after surgery. The primary outcome was the number of analgesic pump compressions at 48 hours after surgery. The secondary outcomes included number of analgesic pump compressions at 6, 12, and 24 hours after surgery; pain scores at 6, 12, 24, and 48 hours after surgery; fentanyl consumption at 48 hours after surgery; interleukin 6 and procalcitonin levels at 12 and 48 hours after surgery; and time to first exhaust.

RESULTS

Overall, 174 primigravida women were included in the intention-to-treat analysis. The number of analgesic pump compressions and pain scores at all 4 time points and fentanyl consumption at 48 hours after surgery were significantly lower in the electroacupuncture treatment groups than in the sham electroacupuncture group (P<.001).

CONCLUSION

Electroacupuncture + patient-controlled intravenous analgesia had a significantly better analgesic effect than sham electroacupuncture + patient-controlled intravenous analgesia within 48 hours after surgery. Thus, electroacupuncture can be considered safe and effective and may improve the efficacy of patient-controlled intravenous analgesia for pain management after cesarean delivery. Electroacupuncture can be recommended as a routine complementary therapy for pain control after cesarean delivery.

Acute Abdominal Pain: Missed Diagnoses, Extra-Abdominal Conditions, and Outcomes

Abdominal pain (AP) is a common reason for presentation to an emergency department (ED). With this prospective, observational all-comer study, we aimed to answer three questions: Which diagnoses are most often missed? What is the incidence of extra-abdominal causes? What is the prognosis of abdominal pain in a tertiary urban European ED? Participants were systematically interviewed for the presence of 35 predefined symptoms. For all patients with abdominal pain, the index visit diagnoses were recorded. Related representation was defined as any representation, investigation, or surgery related to the index visit (open time frame). If a diagnosis changed between index visit and representation, it was classified as missed diagnosis. Among 3960 screened presentations, 480 (12.1%) were due to AP. Among 63 (13.1%) related representations, the most prevalent causes were cholelithiasis, gastroenteritis, and urinary retention. A missed diagnosis was attributed to 27 (5.6%) presentations. Extra-abdominal causes were identified in 162 (43%) presentations. Thirty-day mortality was comparable to that of all other ED patients (2.2% vs. 2.1%). Patients with abdominal pain had a low risk of representation, and the majority of representations due to missed diagnoses were of benign origin. The high incidence of extra-abdominal causes is noteworthy, as this may induce change to differential diagnosis of abdominal pain.

Vitamin D Deficiency and Unclear Abdominal Pain in Patients from Low- and Middle-Income Countries

Background: Abdominal pain is one of the commonest symptoms in emergency departments (EDs). Diagnosis demands full attention and critical thinking, since many diseases manifest atypically and the consequences of overlooking the symptoms may be disastrous. Despite intensive diagnostic procedures, some cases remain elusive and unclear abdominal pain (UAP) is not infrequent. Emerging evidence supports the hypothesis that functional pain might be attributed to vitamin D deficiency (VDD). People with darker or covered skin are predisposed to developing VDD. Patients in Switzerland stemming from low- and middle-income countries (LMIC) are such a population. Aim: To identify cases with UAP in LMIC patients and to compare vitamin D status with a control group. Methods: A retrospective single-center case-control study was carried out from 1 January 2013 to 31 August 2016 in all adult patients (more than 16 years old) stemming from LMIC and presenting at the university ED of Bern with abdominal pain. Vitamin D status was retrieved from these cases when available. The control group consisted of patients without abdominal pain or metabolic diseases and was matched (1:1) to the cases for age, gender, body mass index, geographic distribution, and season of vitamin D estimation. Results: A total of 10,308 cases from LMIC were reported to the ED. In total, 223 cases were identified with UAP. The status of vitamin D was available for 27 patients; 27 matched individuals were subsequently retrieved for the control group. Women made up 56.7% of the UAP group and 43.3% of the control group. The most common origin of the LMIC subjects was southern Europe (20.4%), followed by southern Asia (16.7%) and Eastern Europe (13%). Fourteen UAP patients exhibited severe VDD (<25 nmol/L) versus one in the control group (p = 0.001). The difference remained significant if the patients were identified as having VDD (<50 nmol/L) or not (p = 0.024). Comparison of the means indicated that the UAP group had lower vitamin D levels than the control group (41.3 vs. 53.7 nmol/L, respectively), but this difference was marginal (p = 0.060) and not statistically significant. After adjustment for potential confounders, including gender, mean vitamin D levels remained non-significantly different between groups. In the sub-group analysis, vitamin D levels were lower in women than in men (p = 0.037), compared to the respective controls. Conclusion: This study showed for the first time that patients from LMIC who presented to ED with UAP displayed VDD. Validation from larger studies is warranted to evaluate the linkage of VDD with UAP.