The Cushing reflex and the vasopressin-mediated hemodynamic response to increased intracranial pressure during acute elevations in intraabdominal pressure

Validation of continuous intraabdominal pressure measurement: feasibility and accuracy assessment using a capsular device in in-vivo studies

BACKGROUND

Monitoring Intraabdominal Pressure (IAP) is essential in critical care, as elevated IAP can lead to severe complications, including Abdominal Compartment Syndrome (ACS). Advances in technology, such as digital capsules, have opened new avenues for measuring IAP non-invasively. This study assesses the feasibility and effectiveness of using a capsular device for IAP measurement in an animal model.

METHOD

In our controlled experiment, we anesthetized pigs and simulated elevated IAP conditions by infusing CO2 into the peritoneal cavity. We compared IAP measurements obtained from three different methods: an intravesical catheter (IAPivp), a capsular device (IAPdot), and a direct peritoneal catheter (IAPdir). The data from these methods were analyzed to evaluate agreement and accuracy.

RESULTS

The capsular sensor (IAPdot) provided continuous and accurate detection of IAP over 144 h, with a total of 53,065,487 measurement triplets recorded. The correlation coefficient (R²) between IAPdot and IAPdir was excellent at 0.9241, demonstrating high agreement. Similarly, IAPivp and IAPdir showed strong correlation with an R² of 0.9168.

CONCLUSION

The use of capsular sensors for continuous and accurate assessment of IAP marks a significant advancement in the field of critical care monitoring. The high correlation between measurements from different locations and methods underscores the potential of capsular devices to transform clinical practices by providing reliable, non-invasive IAP monitoring.

Abdominal compartment syndrome in critically ill patients

Intra-abdominal hypertension can have severe consequences, including abdominal compartment syndrome, which can contribute to multi-organ failure. An increase in intra-abdominal hypertension is influenced by factors such as diminished abdominal wall compliance, increased intraluminal content, and certain systemic conditions. Regular measurement of intra-abdominal pressure is essential, and particular attention must be paid to patient positioning. Nonsurgical treatments, such as decompression of intraluminal content using a nasogastric tube, percutaneous drainage, and fluid balance optimization, play crucial roles. Additionally, point-of-care ultrasonography aids in the diagnosis and treatment of intra-abdominal hypertension. Emphasizing the importance of regular measurements, timely decompressive laparotomy is a definitive, but complex, treatment option. Balancing the urgency of surgical intervention against potential postoperative complications is challenging.

Study protocol for a multicenter randomized controlled pilot study on decompressive laparotomy vs. decompressive craniectomy for intractable intracranial pressure after traumatic brain injury: The SCALPEL study

Introduction

Decompressive craniectomy (DC) is the ultimate intervention to lower intracranial pressure (ICP) following severe traumatic brain injury (TBI). However, this intervention is associated with considerable adverse events and a higher proportion of survivors with poor functional outcomes.

Research question

In a multicompartment system ICP is associated with intraabdominal pressure (IAP) due to cerebral venous outflow from the brain. This is the rationale for decompressive laparotomy (DL) to control ICP after TBI as reported by experimental and retrospective clinical data. The safety profile of DL is superior to DC. This study aims to randomly assign patients with intractable high ICP after severe TBI to DL or DC.

Material and methods

Among other inclusion criteria, ICP must be above 20 mmHg (1-12 h) despite sedation and all other measures according to current guidelines. The primary outcome is the Extended Glasgow Outcome Scale assessed after twelve months. Further secondary outcome measures are compartmental pressure values, complications, etc. After 20 initial patients, results will be reviewed by the ethics committees and safety monitoring board to decide on the enrolment of 80 additional patients.

Results

The study is designed to provide not only high-quality prospective data for the first time on this treatment approach, its two-stage design (20 + 80 pts) also provides maximum patient safety. This protocol conforms with the SPIRIT 2013 Statement. Ethics approval was granted by our but also 5 other university ethics committees (registration 473/18S).

Conclusion

Registration was performed prior to study initiation in November 2021 (registration number NCT05115929).

Midterm benefits of metabolic surgery on symptom remission and medication use in patients with pseudotumor cerebri

BACKGROUND

Pseudotumor cerebri is a serious obesity-related disorder that can result in severe complications. The aim of this study was to compare metabolic surgery with medical management of pseudotumor cerebri at a single bariatric center.

METHODS

After institutional review board approval, a retrospective review was conducted of individuals with severe obesity and pseudotumor cerebri (nonbariatric group) and patients with preoperative pseudotumor cerebri (bariatric group). The variables included demographic characteristics, comorbidities, and pseudotumor cerebri-related risk factors. Symptoms, medication use, and body mass index were analyzed during a 4-year follow-up.

RESULTS

A total of 86 patients with pseudotumor cerebri were included in the analysis. In the nonbariatric group (n = 77), the mean age was 34.1 ± 10.5 years and initial body mass index 37.2 ± 6.5 kg/m². Initially, the most common symptom was headache (90.9%; n = 70), with a mean lumbar opening pressure of 341.94 ± 104.50 mm H₂O. In the bariatric group (n = 9), the mean age was 36.1 ± 8.9 years and preoperative body mass index 46.1 ± 5.5 kg/m². The most common preoperative symptom was headache (100%; n = 9), with a lumbar opening pressure of 320 ± 44.27 mm H₂O. During the 4-year follow-up, both groups presented with a significant decrease in pseudotumor cerebri-related symptoms at 3 months (P < .0001). Additionally, pseudotumor cerebri medication use significantly decreased after 3 months in the bariatric group (P = .0406), whereas in the nonbariatric group decreased at 18 months (P = .023). Bariatric patients presented with a significant decrease in body mass index in ≤3 months of surgery (P = .0380), which was not observed in nonbariatric patients (P = .6644).

CONCLUSION

Metabolic surgery seems to provide a greater decrease in pseudotumor cerebri symptoms and medication use in a shorter period of time compared with medical management alone.

Postoperative protocols following endoscopic skull base surgery: An evidence-based review with recommendations

BACKGROUND

Postoperative management strategies for endoscopic skull base surgery (ESBS) vary widely because of limited evidence-based guidance.

METHODS

The PubMed, EMBASE, and Cochrane databases were systematically reviewed from January 1990 through February 2022 to examine 18 postoperative considerations for ESBS. Nonhuman studies, articles written in a language other than English, and case reports were excluded. Studies were assessed for levels of evidence, and each topic's aggregate grade of evidence was evaluated.

RESULTS

A total of 74 studies reporting on 18 postoperative practices were reviewed. Postoperative pain management, prophylactic antibiotics, and lumbar drain use had the highest grades of evidence (B). The literature currently lacks high quality evidence for a majority of the reviewed ESBS precautions. There were no relevant studies to address postoperative urinary catheter use and medical intracranial pressure reduction.

CONCLUSION

The evidence for postoperative ESBS precautions is heterogeneous, scarce, and generally of low quality. Although this review identified the best evidence available in the literature, it suggests the urgent need for more robust evidence. Therefore, additional high-quality studies are needed in order to devise optimal postoperative ESBS protocols.

Optic Nerve Changes Detected with Ocular Ultrasonography during Different Surgical Procedures: A Narrative Review

Ultrasonographic appraisal of the optic nerve sheath diameter has become popular in recent years as a useful diagnostic tool to detect intracranial pressure variations. Intracranial hypertension is a life-threatening disease with possible poor clinical outcomes and can be caused by a variety of neurological and non-neurological conditions. Considering the latter, increases in intracranial pressure have also been described during several surgical procedures. Ocular ultrasonography might be utilized to identify intracranial pressure increases by evaluating optic nerve sheath diameter variations. The aim of this review is to provide a wide overview on the use of the optic nerve ultrasound evaluation to detect intracranial pressure changes during surgical procedures, also discussing the pitfalls of the B-scan technique, the most widely used for such a purpose. PubMed medical database, Web of Science and Scopus were used to carry out this review. The present review showed that ocular ultrasonography could be considered a valuable diagnostic tool in the surgical setting to indirectly assess intracranial pressure. However, the use of the B-scan ultrasound should always be coupled with the standardized A-scan technique for a more accurate, precise and trustworthy ultrasound assessment.

Mean value of B-mode optic nerve sheath diameter as an indicator of increased intracranial pressure: a systematic review and meta-analysis

Objectives

Timely diagnosis and treatment of increased intracranial pressure can decrease morbidity and prevent mortality. The present meta-analysis aims to determine the mean value of the ONSD measured in patients with various elevated ICP etiologies under different clinical settings, as well as comparing the value of ONSD between patients with and without elevated ICP.

Methods

This meta-analysis complied with the Preferred Reporting Items for Systematic Reviews and Meta-analysis Statement8. PubMed, Embase, and Cochrane Library were searched to identify ONSD measured by US for patients with increased ICP from establishment to October 2020.

Results

A total of 779 patients with elevated ICP among 22 studies were included in the present meta-analysis. Studies were published between 2003 and 2020. Eighteen were comparative (18/22, 81.8%), and four were single-armed study (4/22, 18.2%). Twenty were prospective studies (20/22, 90.9%). There was moderate-to-high heterogeneity based on the prediction ellipse area and variance logit of sensitivity and specificity.

Conclusions

The mean value of the ONSD among patients diagnosed with increased ICP was 5.82 mm (95% CI 5.58–6.06 mm). Variations were observed based on etiology of intracranial hypertension, clinical settings where ONSD was measured, and standards for diagnosing intracranial hypertension. The US-ONSD among patient with elevated ICP was significantly higher than the normal control. Although a cut-off value is not clearly determined, these mean values can be implemented to evaluate the sensitivity and specificity of US-ONSD in diagnosing intracranial hypertension in future studies.

Medical Comorbidities Associated With Outcomes in Patients With Traumatic Epidural Hematomas

Background

Traumatic brain injury (TBI) is a frequently encountered neurosurgical pathology with significant morbidity and mortality. One such subtype is the epidural hematoma. Literature regarding the effects of comorbidities in TBI and epidural hematomas is limited.

Methodology

This was a single-center retrospective review of 50 consecutive patients admitted to a level two trauma center with epidural hematomas. Patients were identified using an internal trauma database. Patients were included if they were 18 years of age with a diagnosed epidural hematoma. Outcome variables of Glasgow coma scale (GCS), length of stay in the intensive care unit (ICU) and hospital, and requirement of a neurosurgical procedure were analyzed. Identification of the presence of diagnosed comorbidities was performed including common comorbidities such as obesity, diabetes, hypertension, hyperlipidemia, drug use, tobacco use, cancer, psychiatric disease, and renal disease. Correlations were evaluated using two-sided bivariate analysis (p < 0.05).

Results

A total of 50 patients were included for analysis. Significant correlations with a p-value less of than 0.05 were noted in initial GCS and cancer (r = -0.357, p = 0.011), requirements of an intracranial procedure with a history of gastrointestinal disease (r = 0.377, p = 0.007), and younger age (r = -0.306, p = 0.031). Increased ICU length of stay was related to a history of cancer (r = 0.494, p < 0.001), a history of respiratory disease (r = 0.427, p = 0.002), and a history of psychiatric disease (r = 0.297, p = 0.036). Increased hospital length of stay was related to psychiatric disorders (r = 0.285, p = 0.045). Discharge GCS was negatively associated with a history of hypertension (r = -0.374, p = 0.008), tobacco use (r = -0.417, p = 0.003), drug use (r = -0.294, p = 0.037), and history of cancer (r = -0.303, p = 0.032).

Discussion and Conclusions

In our 50 consecutive patient subset, selected comorbidities demonstrated significant relationships with outcome measures of GCS, need for a procedure, and lengths of stay in the hospital and ICU. Obtaining comorbidity information when available from families can better allow the clinician to optimize treatment and educate loved ones about the potential effects of these comorbidities on the overall health of the patient. Understanding these correlations may allow for a better understanding of the systemic effects of the pathophysiology of injury in epidural hematomas.

Intra-abdominal hypertension and abdominal compartment syndrome: a current review

PURPOSE OF REVIEW

Intra-abdominal hypertension (IAH) and its deleterious effects are present in at least one-third of ICU patients. Increased recognition of IAH has led to significant reduction in the incidence of abdominal compartment syndrome (ACS). Many questions remain regarding what therapeutic interventions truly reduce morbidity and mortality associated with IAH/ACS. Recent research sheds new light on the effects of IAH in individual organ systems and unique disease states. This paper will review recent research in IAH/ACS recognition, treatment, and management.

RECENT FINDINGS

Recent research on IAH/ACS includes an improved understanding of the prevalence of IAH/ACS and confirmation of its independent association with organ failure. Specifically, new research adds clarity to the effects of IAH/ACS on individual organ systems and specific disease states. These results combine to improve the clinical ability to diagnose, monitor, and treat IAH/ACS.

SUMMARY

There is significant research on the broad impact of IAH/ACS in the ICU setting. Focus on IAH/ACS has gone beyond the purview of intensivists and surgeons to include outstanding work by specialists in multiple sub-specialties. These advances have generated improvements in current treatment algorithms. We review recent IAH/ACS literature and have categorized the most pertinent results into organ system-specific contributions.