Relationships between serum electrolyte concentrations and ileus: A joint clinical and mathematical modeling study

Pathophysiology and Management of Postoperative Ileus in Adults and Neonates: A Review

Postoperative ileus (POI) is caused by enteric neural dysfunction and inflammatory response to the stress of surgery as well as the effect of anesthetics and opioid pain medications. POI results in prolonged hospital stays, increased medical costs, and diminished enteral nutrition, rendering it a problem worth tackling. Many cellular pathways are implicated in this disease process, creating numerous opportunities for targeted management strategies. There is a gap in the literature in studies exploring neonatal POI pathophysiology and treatment options. It is well known that neonatal immune and enteric nervous systems are immature, and this results in gut physiology which is distinct from adults. Neonates undergoing abdominal surgery face similar surgical stressors and exposure to medications that cause POI in adults. In this review, we aim to summarize the existing adult and neonatal literature on POI pathophysiology and management and explore applications in the neonatal population.

Postoperative Ileus after Minimally Invasive Colorectal Surgery: A Summary of Current Strategies for Prevention and Management

BACKGROUND

Postoperative ileus (POI) is one of the most common postoperative complications after colorectal surgery and prolongs hospital stays. Minimally invasive surgery (MIS) has reduced POI, but it remains common. This review explores the current methods for preventing and managing POI after MIS.

SUMMARY

Preoperative interventions, including optimising nutrition, preoperative medicationn, and mechanical bowel preparation with oral antibiotics, may have a role in preventing POI. Transversus abdominis plane blocks and lidocaine could replace epidural analgesia in MIS. Fluid overload should be avoided; in some cases, goal-directed fluid therapy may aid in achieving this. Pharmacological agents, such as prucalopride and dexmedetomidine, could target mechanisms underlying POI. New strategies to stimulate vagal nerve activity may promote postoperative gastrointestinal motility. Preoperative bowel stimulation could potentially reduce POI following loop ileostomy closure. However, the evidence base for several interventions remains weak and requires further corroboration with robust studies.

KEY MESSAGES

Despite the increasing use of MIS, POI remains a major issue following colorectal surgery. Further strategies to prevent POI are rapidly emerging. Studies using standardised definitions and perioperative care will help validate these interventions and remove barriers to accurate meta-analysis. Future studies should focus on establishing the impact of these interventions on POI after MIS specifically.

Imaging findings of traumatic injuries in survivors of the 6 February 2023 earthquake in Turkey

In the southeastern part of Turkey, two earthquakes measuring 7.7 and 7.8 on the Richter scale occurred within 9 h on 6 February 2023, causing 120,000 injuries and over 50,000 deaths. Evacuees were transferred to various secondary and tertiary hospitals as the health system and hospitals in the affected region were affected by the earthquake. Injuries were mostly caused by blunt trauma and/or prolonged bruising under rubble. The severity and pattern of traumatic injuries in earthquake victims differed from other trauma patients who were not affected by an earthquake. In addition to traumatic injuries that affected multiple body regions and systems, patients who were trapped under debris for long periods of time were also frequently found to have crush syndrome. Pulmonary thromboembolism and hypoxic-ischaemic brain injury were observed in some patients. In this review, we present the imaging findings of traumatic injuries in earthquake victims, emphasising the earthquake-related distinct injury types.

Imaging in crush injury: a spectrum of findings in survivors of the twin earthquakes on February 6, 2023

On February 6, two major earthquakes with magnitudes of 7.8 and 7.7 on the Richter scale hit Turkey and Northern Syria causing more than 50,000 deaths. In the immediate aftermath of the earthquakes, our major tertiary medical referral center received dozens of cases of crush syndrome, presenting with a variety of imaging findings. Crush syndrome is characterized by hypovolemia, hyperkalemia, and myoglobinuria that can lead to rapid death of victims, despite their survival of staying under wreckage for days. The typical triad of crush syndrome consists of the acute tubular necrosis, paralytic ileus, and third-space edema. In this article, we focus primarily on characteristic imaging findings of earthquake-related crush syndrome and divided them into two distinct subsections: myonecrosis, rapid hypovolemia, excessive third-space edema, acute tubular necrosis, and paralytic ileus, which are directly related to crush syndrome, and typical accompanying findings of earthquake-related crush syndrome. Lower extremity compression in earthquake survivors results in the typical third-space edema. In addition to the lower extremities, other skeletal muscle regions are also affected, especially rotator muscles, trapezius, and pectoral muscles. Although it may be relatively easy to better detect myonecrosis with contrast-enhanced CT scans, changing the windowing of the images may be helpful.

Association of the Controlling Nutritional Status Score with the Development of Postoperative Paralytic Ileus After Radical Cystectomy: Retrospective Cohort Study

OBJECTIVE

Postoperative paralytic ileus is a major adverse event of radical cystectomy, causing prolonged hospitalization. The controlling nutritional status score, consisting of serum albumin, total lymphocyte count, and total cholesterol, indicates the nutritional status and may evaluate gastrointestinal status. This study aimed to clarify the association between the controlling nutritional status score and the development of postoperative paralytic ileus in patients who underwent radical cystectomy with ileal conduit or ileal neobladder.

MATERIALS AND METHODS

We retrospectively analyzed the clinical features of patients who underwent open radical cystectomy or robotic assisted laparoscopic radical cystectomy with ileal conduit or ileal neobladder for bladder cancer between April 2011 and May 2021. The association between clinical variables, including the controlling nutritional status score and the development of postoperative paralytic ileus, was examined.

RESULTS

Out of 133 patients, 34 (26%) developed postoperative paralytic ileus. The patients who developed postoperative paralytic ileus were likely to have a higher controlling nutritional status score (P = .055) compared to those who did not develop postoperative paralytic ileus. Multivariate analysis revealed that a preoperative controlling nutritional status score of ≥1 (odds ratio: 2.90, 95% CI: 1.08-7.80, P = .034) and longer operating time (odds ratio: 3.02, 95% CI: 1.13-8.11, P = .027) were significant independent factors for postoperative paralytic ileus development.

CONCLUSION

A high controlling nutritional status score and long operating time may be risk factors for developing postoperative paralytic ileus in patients who underwent radical cystectomy with ileal conduit or ileal neobladder for bladder cancer. Preoperative controlling nutritional status may be able to predict postoperative paralytic ileus development.

Recording and analysis of slow waves of the small intestine of mice with heart failure

BACKGROUND

Gastrointestinal (GI) symptoms in heart failure (HF) patients are associated with increased morbidity and mortality. We hypothesized that HF reduces bioelectrical activity underlying peristalsis. In this study, we aimed to establish a method to capture and analyze slow waves (SW) in the small intestine in mice with HF.

METHODS

We established a model of HF secondary to coronary artery disease in mice overexpressing tissue-nonspecific alkaline phosphatase (TNAP) in endothelial cells. The myoelectric activity was recorded from the small intestine in live animals under anesthesia. The low- and high-frequency components of SW were isolated in MATLAB and compared between the control (n = 12) and eTNAP groups (n = 8). C-kit-positive interstitial cells of Cajal (ICC) and Pgp9.5-positive myenteric neurons were detected by immunofluorescence. Myenteric ganglia were assessed by hematoxylin and eosin (H&E) staining.

RESULTS

SW activity was successfully captured in vivo, with both high- and low-frequency components. Low-frequency component of SW was not different between endothelial TNAP (eTNAP) and control mice (mean[95% CI]: 0.032[0.025-0.039] vs. 0.040[0.028-0.052]). High-frequency component of SW showed a reduction eTNAP mice relative to controls (0.221[0.140-0.302] vs. 0.394[0.295-0.489], p < 0.01). Dysrhythmia was also apparent upon visual review of signals. The density of ICC and neuronal networks remained the same between the two groups. No significant reduction in the size of myenteric ganglia of eTNAP mice was observed.

CONCLUSIONS

A method to acquire SW activity from small intestines in vivo and isolate low- and high-frequency components was established. The results indicate that HF might be associated with reduced high-frequency SW activity.

The gastric conduction system in health and disease: a translational review

Gastric peristalsis is critically dependent on an underlying electrical conduction system. Recent years have witnessed substantial progress in clarifying the operations of this system, including its pacemaking units, its cellular architecture, and slow-wave propagation patterns. Advanced techniques have been developed for assessing its functions at high spatiotemporal resolutions. This review synthesizes and evaluates this progress, with a focus on human and translational physiology. A current conception of the initiation and conduction of slow-wave activity in the human stomach is provided first, followed by a detailed discussion of its organization at the cellular and tissue level. Particular emphasis is then given to how gastric electrical disorders may contribute to disease states. Gastric dysfunction continues to grow in their prevalence and impact, and while gastric dysrhythmia is established as a clear and pervasive feature in several major gastric disorders, its role in explaining pathophysiology and informing therapy is still emerging. New insights from high-resolution gastric mapping are evaluated, together with historical data from electrogastrography, and the physiological relevance of emerging biomarkers from body surface mapping such as retrograde propagating slow waves. Knowledge gaps requiring further physiological research are highlighted.