Predictive value of Bispectral Index (BIS) in emergency neurosurgical patients: Loss of BIS reactivity to propofol predicts poor functional outcomes.

AIM: In emergency neurosurgical patients, evaluation with Glasgow Coma Scale (GCS) alone immediately after stopping sedation post-operatively might not differentiate those with good recovery from those with poor outcomes at 3 months. This study aimed to evaluate the prognostic value of measuring the Bispectral Index (BIS) and the correlation to propofol dosage during the use of sedation in the early post-operative period. METHODS: This is a prospective study on consecutive post-operative neurosurgical patients admitted to the neurosurgical ICU on propofol sedation. The primary outcome was the correlation between early post-operative BIS and the Propofol dosage with the modified Rankin scale (mRS) at 3 months. Secondary outcomes included the post-operative propofol requirement in patients with good functional outcomes (mRS 0-3) versus poor functional outcomes (mRS 4-6) at 3 months. RESULTS: In total, 728 BIS readings were collected from twenty-four patients for analysis. The BIS readings were significantly correlated to the propofol dosage in patients with good function outcomes at 3 months (p < 0.0001). BIS readings in patients with no associations to changes in propofol dosage during their ICU stay had poor outcomes (mRS 4-6) at 3 months (r = -0.0407). For patients with good functional outcomes at 3 months, a significantly higher propofol dosage was used for deep sedation (BIS 40 - 60) during the post-operative period (p < 0.001). CONCLUSION: For emergency neurosurgical patients whose BIS readings had lost correlation to the propofol dosage upon recovery, their functional outcomes at 3 months were poor. For those with good functional outcomes at 3 months, a significantly higher propofol dosage was required for deep sedation during their ICU stay. Patients with preserved correlation of BIS readings to changes in propofol dosages during the early post-operative period were associated with good functional outcomes at 3 months.

An Update of Neuroanesthesia for Intraoperative Brain Mapping Craniotomy.

The perioperative multidisciplinary team approach has probably been best exemplified by the care of awake craniotomy patients. Advancement in anesthesia and meticulous perioperative care has supported the safety and complexity of the surgical and mapping efforts in glioma resection. The discussions in this review will emphasize on anesthetic and perioperative management strategies to prevent complications and minimize their effects if they occur, including current practice guidelines in anesthesia, updates on the applications of anesthetic medications, and emerging devices. Planning the anesthetic and perioperative management is based on understanding the pharmacology of the medications, the goals of different stages of the surgery and mapping, and anticipating potential problems.

Listeria monocytogenes Peritonitis in a Patient Receiving Continuous Ambulatory Peritoneal Dialysis: A Case Report and Review of the Literature.

Listeria monocytogenes is a rare cause of peritoneal dialysis-related peritonitis. Only a handful of cases have been reported, and the optimal management is still uncertain. We present a case of Listeria monocytogenes peritonitis and perform a review of the literature to elucidate optimal antibiotic therapy.

Tracheostomy during COVID-19 pandemic-Novel approach.

BACKGROUND: This study describes a novel approach in reducing SARS-CoV-2 transmission during tracheostomy. METHODS: Five patients underwent tracheostomy between April 1, 2020 and April 17, 2020. A clear and sterile plastic drape was used as an additional physical barrier against droplets and aerosols. Operative diagnosis; droplet count and distribution on plastic sheet and face shields were documented. RESULTS: Tracheostomy was performed for patients with carcinoma of tonsil (n = 2) and nasopharynx (n = 1), and aspiration pneumonia (n = 2). Droplet contamination was noted on all plastic sheets (n = 5). Droplet contamination was most severe over the central surface at 91.5% (86.7%-100.0%) followed by the left and right lateral surfaces at 5.2% (6.7%-10.0%) and 3.3% (6.7%-10.0%), respectively. No droplet contamination was noted on all face shields. CONCLUSION: Plastic drapes can help reduce viral transmission to health care providers during tracheostomy. Face shields may be spared which in turn helps to conserve resources during the novel coronavirus disease 2019 pandemic.

Home hemodialysis associated infection-The "Achilles' Heel" of intensive hemodialysis.

Home hemodialysis (HHD) is emerging as an important alternate renal replacement therapy. Although there are multiple clinical advantages with HHD, concerns surrounding increased risks of infection in this group of patients remain a major barrier to its implementation. In contrast to conventional hemodialysis, infection related complication represents the major morbidity in this mode of renal replacement therapy. Vascular access related infection is an important cause of infection in this population. Use of central vein catheters and buttonhole cannulation in HHD are important modifiable risk factors for HHD associated infection. Several preventive measures are suggested in the literature, which will require further prospective validation.

Effect of alternate night nocturnal home hemodialysis on anemia control in patients with end-stage renal disease.

Nocturnal home hemodialysis (NHHD) has shown promising results in various clinical parameters. Whether NHHD provide benefit in anemia management remains controversial. This study aims to investigate whether anemia and erythropoiesis-stimulating agent (ESA) requirement are improved in patients receiving alternate night NHHD compared with conventional hemodialysis (CHD). In this retrospective controlled study, a clinical data of 23 patients receiving NHHD were compared with 25 in-center CHD patients. Hemoglobin level, ESA requirement, iron profile, and dialysis adequacy indexes were compared between the two groups. Hemoglobin level increased from baseline of 9.37 ± 1.39 g/dL to 11.34 ± 2.41 g/dL at 24 months (P < 0.001) and ESA requirement decreased from 103.44 ± 53.55 U/kg/week to 47.33 ± 50.62 U/kg/week (P < 0.001) in NHHD patients. ESA requirement further reduced after the first year of NHHD (P = 0.037). Standard Kt/V increased from baseline of 2.02 ± 0.28 to 3.52 ± 0.30 at 24 months (P < 0.001). At 24 months, hemoglobin level increased by 1.98 ± 2.74 g/dL in the NHHD group while it decreased by 0.20 ± 2.32 g/dL in the CHD group (P = 0.007). ESA requirement decreased by 53.49 ± 55.50 U/kg/week in NHHD patients whereas it increased by 16.22 ± 50.01 U/kg/week in CHD patients (P < 0.001). Twenty-six percent of NHHD patients were able to stop ESA compared with none in the CHD group. Standard Kt/V showed greater increase in the NHHD group. (1.49 ± 0.36 in NHHD vs. 0.18 ± 0.31 in CHD, P = 0.005). NHHD with an alternate night schedule improves anemia and reduces ESA requirement as a result of enhanced uremic clearance. This benefit extended beyond the first year of NHHD.

Long-term outcomes of living kidney donors: a single centre experience of 29 years.

AIM: Living kidney donation provides the best source of kidney graft. The mortality and morbidity rates are small but the long-term effects have not been studied. This is a report on our 29-year experience of living kidney donation. METHODS: All living donors were arranged to have follow-ups. Defaulters were traced via a territory-wide computer system. RESULTS: A total of 149 living kidney donor operations were performed. 136/149 records were available. 41 defaulted follow-up. One donor died of multiple myeloma. The male to female ratio was 1.00 to 1.52. Mean age at donation was 33.94±9.66 years. Mean follow-up duration was 160.39±87.96 months. Hypertension was diagnosed in 27 donors (19.9%). 22 donors (17.3%) had stage 3 chronic kidney disease (CKD). Glomerular filtration rate (GFR) dropped from 90.95±15.62 mL/min per 1.73 m2 at time 0 to 66.29±12.06 mL/min per 1.73 m2 at 2 years. GFR improved subsequently and remained stable for 25 years. Age at donation was associated with hypertension (HT) in univariate and multivariate analyses. HT was not associated with sex or GFRs over time. Using binary logistic regression, age at donation was associated with the development of stage 3 CKD and GFR before donation was associated with lower CKD risk. In multivariate analysis, only age at donation was associated with CKD. Other co-morbidities included: hyperlipidaemia 16/136, diabetes mellitus 6/136, cardiovascular event 1/136, stroke 1/136 and cancer 5/136. CONCLUSIONS: Living kidney donors had reductions in GFR post uninephrectomy with subsequent improvement. A significant proportion developed HT and stage 3 CKD. Age at donation was a strong determinant of development of HT and stage 3 CKD.

One year experience of nocturnal home haemodialysis with an alternate night schedule in Hong Kong.

AIM: Nocturnal home haemodialysis (NHHD) was started in Hong Kong in 2006. The experience of 1 year of NHHD with an alternate night schedule in two local centres is reported. METHODS: The clinical parameters of 14 patients who had completed 1 year of NHHD were retrospectively analyzed. All patients were receiving an alternate night schedule (3.5 sessions/week) for 6-8 h/session. RESULTS: After 1 year of NHHD, haemoglobin levels increased from 9.6±1.6 g/dL before NHHD to 11.4±2.2 g/dL (P<0.05) despite a reduction in erythropoietin dose requirement from 120.6±44.3 to 59.4±74.6 U/kg/week (P<0.05). Four patients (29%) were able to stop taking erythropoietin after NHHD. Serum phosphate levels reduced from 2.33±0.41 to 1.59±0.29 mmol/L (P<0.01) and calcium phosphate product decreased from 5.29±0.96 to 3.74±0.90 mmol2/L2 (P<0.01). Phosphate binder dose was greatly reduced and eight patients (67%) were able to stop taking phosphate binders. The number of antihypertensive medications tended to reduced from 2.5±1.3 to 1.6±1.5 (P=0.067) with four patients (29%) able to stop antihypertensives. Left ventricular mass index decreased from 186±62 to 168±60 g/m2 (P=0.463) although this was not statistically significant. Weekly spKt/V during conventional haemodialysis was 3.63±0.95 while that during NHHD was three times higher at 11.09±6.44 (P<0.01). The quality of life indexes also showed improvement. CONCLUSION: This 1 year experience of alternate night NHHD demonstrates benefits in terms of anaemia control, erythropoietin requirement, serum phosphate and calcium phosphate product reduction, blood pressure control, haemodialysis adequacy and quality of life. NHHD with an alternate night schedule is a promising dialytic therapy for patients receiving chronic haemodialysis in this locality.

Microglia overexpressing the macrophage colony-stimulating factor receptor are neuroprotective in a microglial-hippocampal organotypic coculture system.

Microglia with increased expression of the macrophage colony-stimulating factor receptor (M-CSFR; c-fms) are found surrounding plaques in Alzheimer's disease (AD) and in mouse models for AD and after ischemic or traumatic brain injury. Increased expression of M-CSFR causes microglia to adopt an activated state that results in proliferation, release of cytokines, and enhanced phagocytosis. To determine whether M-CSFR-induced microglial activation affects neuronal survival, we assembled a coculture system consisting of BV-2 microglia transfected to overexpress the M-CSFR and hippocampal organotypic slices treated with NMDA. Twenty-four hours after assembly of the coculture, microglia overexpressing M-CSFR proliferated at a higher rate than nontransfected control cells and exhibited enhanced migration toward NMDA-injured hippocampal cultures. Surprisingly, coculture with c-fms-transfected microglia resulted in a dramatic reduction in NMDA-induced neurotoxicity. Similar results were observed when cocultures were treated with the teratogen cyclophosphamide. Biolistic overexpression of M-CSFR on microglia endogenous to the organotypic culture also rescued neurons from excitotoxicity. Furthermore, c-fms-transfected microglia increased neuronal expression of macrophage colony-stimulating factor (M-CSF), the M-CSFR, and neurotrophin receptors in the NMDA-treated slices, as determined with laser capture microdissection. In the coculture system, direct contact between the exogenous microglia and the slice was necessary for neuroprotection. Finally, blocking expression of the M-CSF ligand by exogenous c-fms-transfected microglia with a hammerhead ribozyme compromised their neuroprotective properties. These results demonstrate a protective role for microglia overexpressing M-CSFR in our coculture system and suggest under certain circumstances, activated microglia can help rather than harm neurons subjected to excitotoxic and teratogen-induced injury.

Biolistic expression of the macrophage colony stimulating factor receptor in organotypic cultures induces an inflammatory response.

The receptor for macrophage colony-stimulating factor (M-CSFR; c-fms) is expressed at increased levels by microglia in Alzheimer's disease (AD) and in mouse models for AD. Increased expression of M-CSFR on cultured microglia results in a strong proinflammatory response, but the relevance of this cell culture finding to intact brain is unknown. To determine the effects of increased microglial expression of M-CSFR in a complex organotypic environment, we developed a system for biolistic transfection of microglia in hippocampal slice cultures. The promoter for the Mac-1 integrin alpha subunit CD11b is active in cells of myeloid origin. In the brain, CD11b expression is restricted to microglia. Constructs consisting of the promoter for CD11b and a c-fms cDNA or an enhanced green fluorescent protein (EGFP) cDNA were introduced into monotypic cultures of microglia, neurons, and astrocytes. Strong CD11b promoter activity was observed in microglia, whereas little activity was observed in other cell types. Biolistic transfection of organotypic hippocampal cultures with the CD11b/c-fms construct resulted in expression of the c-fms mRNA and protein that was localized to microglia. Furthermore, biolistic overexpression of M-CSFR on microglia resulted in significantly increased production by the hippocampal cultures of the proinflammatory cytokines interleukin (IL)-1alpha macrophage inflammatory protein (MIP-1alpha), and trends toward increased production of IL-6 and M-CSF. These findings demonstrate that microglial overexpression of M-CSFR in an organotypic environment induces an inflammatory response, and suggest that increased microglial expression of M-CSFR could contribute to the inflammatory response observed in AD brain.