Decompressive craniectomy guided by cerebral microdialysis and brain tissue oxygenation in a patient with meningitis

Autoimmune and inflammatory neurological disorders in the intensive care unit

PURPOSE OF REVIEW

The present review summarizes the diagnostic approach to autoimmune encephalitis (AE) in the intensive care unit (ICU) and provides practical guidance on therapeutic management.

RECENT FINDINGS

Autoimmune encephalitis represents a group of immune-mediated brain diseases associated with antibodies that are pathogenic against central nervous system proteins. Recent findings suggests that the diagnosis of AE requires a multidisciplinary approach including appropriate recognition of common clinical syndromes, brain imaging and electroencephalography to confirm focal pathology, and cerebrospinal fluid and serum tests to rule out common brain infections, and to detect autoantibodies. ICU admission may be necessary at AE onset because of altered mental status, refractory seizures, and/or dysautonomia. Early management in ICU includes prompt initiation of immunotherapy, detection and treatment of seizures, and supportive care with neuromonitoring. In parallel, screening for neoplasm should be systematically performed. Despite severe presentation, epidemiological studies suggest that functional recovery is likely under appropriate therapy, even after prolonged ICU stays.

CONCLUSION

AE and related disorders are increasingly recognized in the ICU population. Critical care physicians should be aware of these conditions and consider them early in the differential diagnosis of patients presenting with unexplained encephalopathy. A multidisciplinary approach is mandatory for diagnosis, ICU management, specific therapy, and prognostication.

Early detection of anastomotic leakage after pancreatoduodenectomy with microdialysis catheters: an observational Study

BACKGROUND

Microdialysis catheters can detect focal inflammation and ischemia, and thereby have a potential for early detection of anastomotic leakages after pancreatoduodenectomy. The aim was to investigate whether microdialysis catheters placed near the pancreaticojejunostomy can detect leakage earlier than the current standard of care.

METHODS

Thirty-five patients with a median age 69 years were included. Two microdialysis catheters were placed at the end of surgery; one at the pancreaticojejunostomy, and one at the hepaticojejunostomy. Concentrations of glucose, lactate, pyruvate, and glycerol were analyzed hourly in the microdialysate during the first 24 h, and every 2-4 h thereafter.

RESULTS

Seven patients with postoperative pancreatic fistulae (POPF) had significantly higher glycerol levels (P < 0.01) in the microdialysate already in the first postoperative samples. Glycerol concentrations >400 μmol/L during the first 12 postoperative hours detected patients with POPF with a sensitivity of 100% and a specificity of 93% (P < 0.001). After 24 h, lactate and lactate-to-pyruvate ratio were significantly higher (P < 0.05) and glucose was significantly lower (P < 0.05) in patients with POPF.

CONCLUSION

High levels of glycerol in microdialysate was an early detector of POPF. The subsequent inflammation was detected as increase in lactate and lactate-to-pyruvate ratio and a decrease in glucose (NCT03627559).

Invasive neuromonitoring and neurological intensive care unit management in life-threatening central nervous system infections

PURPOSE OF REVIEW

Patients with infectious diseases of the central nervous system (CNS) commonly require treatment in the intensive care unit (ICU). In a subset of patients with a life-threatening course, a more aggressive and invasive management is required. Treatment relies on the expertise of the intensivists as most recommendations are currently not based on a high level of evidence.

RECENT FINDINGS

Published data suggest that an invasive brain-focused management should be considered in life-threatening CNS infections. Brain resuscitation by adequate control of intracranial pressure (ICP) and optimization of cerebral perfusion, oxygen and glucose delivery supports the idea of personalized medicine. Recent advances in monitoring techniques help to guide clinicians to improve neurocritical care management in these patients with severe disease. Robust data on the long-term effect of decompressive craniectomy and targeted temperature management are lacking, however, these interventions can be life-saving in individual patients in the setting of a potentially fatal situation such as refractory elevated ICP.

SUMMARY

Advances in the neurocritical care management and progress in monitoring techniques in specialized neuro-ICUs may help to preserve brain function and prevent a deleterious cascade of secondary brain damage in life-threatening CNS infections.

Patterns of cerebral tissue oxygen tension and cytoplasmic redox state in bacterial meningitis

BACKGROUND

Compromised cerebral energy metabolism is common in patients with bacterial meningitis. In this study, simultaneous measurements of cerebral oxygen tension and lactate/pyruvate ratio were compared to explore whether disturbed energy metabolism was usually caused by insufficient tissue oxygenation or compromised oxidative metabolism of pyruvate indicating mitochondrial dysfunction.

SUBJECT AND METHODS

Ten consecutive patients with severe streptococcus meningitis were included in this prospective cohort study. Intracranial pressure, brain tissue oxygen tension (PbtO₂ ), and energy metabolism (intracerebral microdialysis) were continuously monitored in nine patients. A cerebral lactate/pyruvate (LP) ratio <30 was considered indicating normal oxidative metabolism, LP ratio >30 simultaneously with pyruvate below lower normal level (70 µmol/L) was interpreted as biochemical indication of ischemia, and LP ratio >30 simultaneously with a normal or increased level of pyruvate was interpreted as mitochondrial dysfunction. The biochemical variables were compared with PbtO₂ simultaneously monitored within the same cerebral region.

RESULTS

In two cases, the LP ratio was normal during the whole study period and the simultaneously monitored PbtO₂ was 18 ± 6 mm Hg. In six cases, interpreted as mitochondrial dysfunction, the simultaneously monitored PbtO₂ was 20 ± 6 mm Hg and without correlation with the LP ratio. In one patient, exhibiting a pattern interpreted as ischemia, PbtO₂ decreased below 10 mm Hg and a correlation between LP and PbtO₂ was observed.

CONCLUSION

This study demonstrated that compromised cerebral energy metabolism, evidenced by increased LP ratio, was common in patients with severe bacterial meningitis while not related to insufficient tissue oxygenation.

Timing of Decompressive Craniectomy for Ischemic Stroke and Traumatic Brain Injury: A Review

While studies have demonstrated that decompressive craniectomy after stroke or TBI improves mortality, there is much controversy regarding when decompressive craniectomy is optimally performed. The goal of this paper is to synthesize the data regarding timing of craniectomy for malignant stroke and traumatic brain injury (TBI) based on studied time windows and clinical correlates of herniation. In stroke patients, evidence supports that early decompression performed within 24 h or before clinical signs of herniation may improve overall mortality and functional outcomes. In adult TBI patients, published results demonstrate that early decompressive craniectomy within 24 h of injury may reduce mortality and improve functional outcomes when compared to late decompressive craniectomy. In contrast to the stroke data, preliminary TBI data have demonstrated that decompressive craniectomy after radiographic signs of herniation may still lead to improved functional outcomes compared to medical management. In pediatric TBI patients, there is also evidence for better functional outcomes when treated with decompressive craniectomy, regardless of timing. More high quality data are needed, particularly that which incorporates a broader set of metrics into decision-making surrounding cranial decompression. In particular, advanced neuromonitoring and imaging technologies may be useful adjuncts in determining the optimal time for decompression in appropriate patients.

The role of ICP monitoring in meningitis

Intracranial pressure (ICP) monitoring has been widely accepted in the management of traumatic brain injury. However, its use in other pathologies that affect ICP has not been advocated as strongly, especially in CNS infections. Despite the most aggressive and novel antimicrobial therapies for meningitis, the mortality rate associated with this disease is far from satisfactory. Although intracranial hypertension and subsequent death have long been known to complicate meningitis, no specific guidelines targeting ICP monitoring are available. A review of the literature was performed to understand the pathophysiology of elevated ICP in meningitis, diagnostic challenges, and clinical outcomes in the use of ICP monitoring.

Decompressive craniectomy and early cranioplasty in a 15-year-old boy with N. meningitidis meningitis

Background:

Intracranial hypertension is a well-known life-threatening complication of bacterial meningitis. Investigations on decompressive craniectomy after failure of conservative management are scarce, but this surgical treatment should be considered and performed expeditiously, as it lowers the intracranial pressure and improves brain tissue oxygenation. Early cranioplasty can further aid the rehabilitation.

Case Description:

A 15-year-old boy was admitted to our emergency department because of sudden onset of neurologic decline and consecutive loss of consciousness. Clinical examination and imaging showed elevated intracranial pressure, leading to the suspected diagnosis of meningitis. Intracranial pressure monitoring was installed, but the initiated conservative management failed. Finally, the patient underwent bilateral decompressive craniectomy. The microbiological test showed growth of Neisseria meningitidis. After full neurologic recovery, cranioplasty with two CAD/CAM titanium implants was conducted successfully.

Conclusions:

This unique report shows that decompressive craniotomy with duroplasty may be a crucial therapeutic approach in bacterial meningitis with refractory increased intracranial pressure and brainstem compression. Early cranioplasty with a patient-specific implant allowed the early and full reintegration of the patient.

Neuro-intensive treatment targeting intracranial hypertension improves outcome in severe bacterial meningitis: an intervention-control study

OBJECTIVE

To evaluate the efficacy of early intracranial pressure (ICP)-targeted treatment, compared to standard intensive care, in adults with community acquired acute bacterial meningitis (ABM) and severely impaired consciousness.

DESIGN

A prospectively designed intervention-control comparison study of adult cases from September 2004 to January 2012.

PATIENTS

Included patients were confirmed ABM-cases, aged 16-75 years, with severely impaired mental status on admission. Fifty-two patients, given ICP-targeted treatment at the neuro-intensive care unit, and 53 control cases, treated with conventional intensive care, were included. All the patients received intensive care with mechanical ventilation, sedation, antibiotics and corticosteroids according to current guidelines. Additional ICP-treatment in the intervention group included cerebrospinal fluid drainage using external ventricular catheters (n = 48), osmotherapy (n = 21), hyperventilation (n = 13), external cooling (n = 9), gram-doses of methylprednisolone (n = 3) and deep barbiturate sedation (n = 2) aiming at ICP <20 mmHg and a cerebral perfusion pressure of >50 mmHg.

MEASUREMENTS

The primary endpoint was mortality at two months and secondary endpoint was Glasgow outcome score and hearing ability at follow-up at 2-6 months.

OUTCOMES

The mortality was significantly lower in the intervention group compared to controls, 5/52 (10%) versus 16/53 (30%; relative risk reduction 68%; p<0.05). Furthermore, only 17 patients (32%) in the control group fully recovered compared to 28 (54%) in the intervention group (relative risk reduction 40%; p<0.05).

CONCLUSIONS

Early neuro-intensive care using ICP-targeted therapy, mainly cerebrospinal fluid drainage, reduces mortality and improves the overall outcome in adult patients with ABM and severely impaired mental status on admission.

Neurointensive care of patients with severe community-acquired meningitis

BACKGROUND

Reports about neurointensive care of severe community-acquired meningitis are few. The aims of this retrospective study were to review the acute clinical course, management and outcome in a series of bacterial meningitis patients receiving neurointensive care.

METHODS

Thirty patients (median age 51, range 1-81) admitted from a population of 2 million people during 7 years were studied. The neurointensive care protocol included escalated stepwise treatment with mild hyperventilation, cerebrospinal fluid (CSF) drainage, continuous thiopentotal infusion and decompressive craniectomy. Clinical outcome was assessed using the Glasgow outcome scale.

RESULTS

Twenty-eight patients did not respond to commands on arrival, five were non-reacting and five had dilated pupils. Twenty-two patients had positive CSF cultures: Streptococcus pneumoniae (n=18), Neisseria meningitidis (n=2), β-streptococcus group A (n=1) and Staphylococcus aureus (n=1). Thirty-five patients were mechanically ventilated. Intracranial pressure (ICP) was monitored in 28 patients (intraventricular catheter=26, intracerebral transducers=2). CSF was drained in 15 patients. Three patients received thiopentothal. Increased ICP (>20 mmHg) was observed in 7/26 patients with available ICP data. Six patients died during neurointensive care: total brain infarction (n=4), cardiac arrest (n=1) and treatment withdrawal (n=1). Seven patients died after discharge, three due to meningitis complications. At follow-up, 14 patients showed good recovery, six moderate disability, two severe disability and 13 were dead.

CONCLUSION

Patients judged to have severe meningitis should be admitted to neurointensive care units without delay for ICP monitoring and management according to modern neurointensive care principles.

Ultrasonography of the optic nerve in neurocritically ill patients

The rapid diagnosis of intracranial hypertension is urgently needed for therapeutic reasons in various clinical settings. This can rarely be achieved without invasive procedures such as intracranial pressure (ICP) monitoring or neuroimaging. The optic nerve is surrounded by cerebrospinal fluid (CSF) and dura mater, which forms the optic nerve sheath (ONS). Because of the connection with the intracranial subarachnoid space, ONS diameter (ONSD) is influenced by CSF pressure variations. Bedside ultrasonographic measurement of ONSD has been proposed as a non-invasive and reliable means to detect raised ICP in neurocritically ill patients. In several studies, it proves to have a good correlation with the direct measurement of ICP and a low interobserver variability. However, no general consensus exists over the upper normal ONSD limit. We performed a review of the literature on the use of the ultrasonography of the optic nerve in the evaluation of patients with suspected intracranial hypertension. The aim of this review is to describe the technique and to assess the validity of this diagnostic method.