Could MicroRNA be Neurological Prognosis Biomarkers after Cardiac Arrest?

For patients monitored in intensive care units in the aftermath of a cardiac arrest, one of the well-established difficulties of care after resuscitation is the ability to perform the necessary prognostic assessments as accurately and early as possible. Although current guidelines include algorithms to determine prognosis, there are still missing links and uncertainties. Biomarkers obtained from peripheral blood are generally non-invasive and easy to obtain. Although the potential to use microRNA as a prognostic biomarker after cardiac arrest has received less interest recently, its popularity has increased in the last few years. By identifying prognostic biomarkers within 24 h of cardiac arrest, clinicians in intensive care could gain valuable insights to guide patient outcomes and predict both mortality and survival rates.

Vaccination status of COVID-19 patients followed up in the ICU in a country with heterologous vaccination policy: A multicenter national study in Turkey

OBJECTIVE

Vaccination against severe acute respiratory syndrome coronavirus-2 (SARS-2) prevents the development of serious diseases has been shown in many studies. However, the effect of vaccination on outcomes in COVID-19 patients requiring intensive care is not clear.

METHODS

This is a retrospective multicenter study conducted in 17 intensive care unit (ICU) in Turkey between January 1, 2021, and December 31, 2021. Patients aged 18 years and older who were diagnosed with COVID-19 and followed in ICU were included in the study. Patients who have never been vaccinated and patients who have been vaccinated with a single dose were considered unvaccinated. Logistic regression models were fit for the two outcomes (28-day mortality and in-hospital mortality).

RESULTS

A total of 2968 patients were included final analysis. The most of patients followed in the ICU during the study period were unvaccinated (58.5%). Vaccinated patients were older, had higher Charlson comorbidity index (CCI), and had higher APACHE-2 scores than unvaccinated patients. Risk for 28-day mortality and in-hospital mortality was similar in across the year both vaccinated and unvaccinated patients. However, risk for in-hospital mortality and 28-day mortality was higher in the unvaccinated patients in quarter 4 adjusted for gender and CCI (OR: 1.45, 95% CI: 1.06-1.99 and OR: 1.42, 95% CI: 1.03-1.96, respectively) compared to the vaccinated group.

CONCLUSION

Despite effective vaccination, fully vaccinated patients may be admitted to ICU because of disease severity. Unvaccinated patients were younger and had fewer comorbid conditions. Unvaccinated patients have an increased risk of 28-day mortality when adjusted for gender and CCI.

Investigation of high flow nasal cannule efficiency with electric impedance tomography based parameters in COVID-19 adults patients: a retrospective study

Background/Aim

This study aimed to investigate the effects of oxygen therapy using a high flow nasal cannula (HFNC) on patients diagnosed with COVID-19 Acute Respiratory Distress Syndrome (C-ARDS) by utilizing electrical impedance tomography (EIT)-based parameters.

Materials and Methods

Oxygen therapy was administered to the patients at two different flow rates and two different positions: T0-baseline measurements were taken in the supine position before any therapy was initiated. T1-HFNC was administered in the supine position with a flow rate of 30 L/min. T2-HFNC was administered in the supine position with a flow rate of 50 L/min. T3-HFNC was administered in the prone position with a flow rate of 30 L/min. T4-HFNC was administered in the prone position with a flow rate of 50 L/min. EIT-based parameters (global inhomogeneity index (GI index), center of ventilation (CoV), regional ventilation delay index (RVD index), region of interest ratio (ROI ratio)), as well as respiratory and hemodynamic parameters of the patients, were recorded from the database.

Results

A total of twenty patients were included in this retrospective observational study. The mean age of the included patients was 64.3 ± 10.6 years. Statistically significant differences were observed in the measurements of GI index, CoV, RVD index, ROI ratio, PaO2/FiO2 ratio, respiratory rate, and mean arterial pressure parameters across different time intervals (p < 0.005). Pairwise comparisons of EIT parameters and measurements of respiratory and hemodynamic parameters at five different time points revealed statistically significant differences. For the GI index, significant differences were observed between the mean measurements taken at T0-T1, T0-T2, T0-T3, T0-T4, T1-T3, T1-T4, T2-T3, T2-T4, and T3-T4 time intervals (p < 0.05). Regarding CoV, significant differences were found between the mean measurements taken at T0-T3, T1-T3, T2-T3, and T3-T4 time intervals (p < 0.05). Additionally, for the ROI ratio, significant differences were observed between the measurement averages taken at each time interval (p < 0.05).

Conclusion

Our findings suggest that prone positioning during the management of C-ARDS patients leads to improved lung homogeneity, as indicated by EIT parameters. However, further research is required to enhance the visualization of ventilation using EIT.

COVID-19 Pneumonia After SARS-CoV-2 Vaccination with CoronaVac: A Case Series from Turkey

Coronavirus disease 2019 is a novel viral infection that has caused a pandemic globally. Many kinds of vaccine development studies were conducted to prevent the spread and deaths. The CoronaVac is the most commonly used vaccine in Turkey. Phase 3 trials from various countries revealed that CoronaVac efficacy ranged from 50.7% to 91.25% but increased in moderate or severe cases to 100%. Additionally, it was remarkable owing to high seroconversion rates achieving up to 100%. After the vaccine campaign began in Turkey, critically ill patients continued to admit to our center’s intensive care unit though they had been vaccinated with 2 doses of CoronaVac. The clinical course of these patients revealed that they are still at high risk of severe disease and death. Therefore, we aimed to share these patients’ clinical characteristics and disease course, laboratory, and radiologic data.

Needs of family members of patients admitted to a university hospital critical care unit, Izmir Turkey: comparison of nurse and family perceptions

Purpose:

This study aims to compare the perceptions of nurses and families on the needs of the relatives of the patients in Intensive Care Unit (ICU).

Methods

This cross-sectional study was conducted in the ICU of a university hospital. The study comprised 213 critical care patients’ relatives and 54 nurses working in the same ICU. Data were collected using the Turkish version of Critical Care Family Needs Inventory (CCFNI) and a questionnaire on the characteristics of the participants. The difference between the perceptions of families and nurses was analyzed using Student t-test. Results: CCFNI’s assurance/proximity subscale mean scores ranked first among bothpatients and nurses. The item “To be assured the best care possible is being given to the patient” was the top priority for both groups. Mean assurance/proximity and information dimensions of relatives were significantly higher compared to nurses (p < 0.001). No significant difference was found between the perception of patient relatives and nurses related to support and comfort dimensions (p < 0.05).

Conclusion

The needs of the relatives of patients are underestimated by nurses. This inhibited the performance of ICU nurses in line with the holistic care approach. Educational objectives that include the needs of ICU patients’ relatives should be incorporated into the undergraduate and in-service training of nurses. Policies should be established to create space and time for effective relative-nurse communication.

COVID-19 Pandemic Action Plan of a University Hospital

In December 2019, in Wuhan, China, scientists observed a sudden and sharp increase in the number of cases of pneumonia and acute respiratory distress syndrome of an unknown origin. By the end of January 2020, the outbreak had spread to Asia, Europe, America, and Australia. In this article, we have outlined the pandemic action plan of our university hospital.

Acute kidney injury following colistin treatment in critically-ill patients: may glucocorticoids protect?

Nephrotoxicity following colistin administration is common and factors alleviating nephrotoxicity are yet to be determined. We retrospectively evaluated outcomes of subjects who were treated with colistin (n = 133) and with antibiotics other than colistin (control, n = 133) in intensive care units. Acute kidney injury (AKI) occurred in 69.2% and 29.3% of patients in colistin and control groups, respectively (p < 0.001). In the colistin group, glucocorticoid exposure was more common in subjects who did not develop AKI (p < 0.001). This was not the case in the control group. In the colistin cohort, older age (per 10 years, odds ratio [OR] 1.41, 95% CI 1.05-1.91; p = 0.025), PPI use (OR 3.30, 95% CI 1.18-9.23; p = 0.023) and furosemide treatment (OR 2.66, 95% CI 1.01-6.98; p = 0.047) were independently associated with the development of AKI while glucocorticoid treatment (OR 0.23, 95% CI 0.10-0.53; p = 0.001) was independently associated with reduced risk of AKI. Mortality was observed in 74 patients in the colistin cohort (55.6%). A higher APACHE-II score (OR 1.17, 95% CI 1.08-1.26; p < 0.001) was independently associated with mortality while a higher serum albumin level (per 1 g/dL increase, OR 0.20, 95% CI 0.070-0.60; p = 0.004) was associated with a lower risk of mortality. In conclusion, glucocorticoid exposure is associated with a lower risk of AKI caused by colistin therapy in critically-ill patients. Prospective studies are needed to confirm these findings and determine the optimal type, dose and duration of glucocorticoid therapy.

Current Statement of Intensive Care Units in Turkey: Data obtained from 67 Centers

OBJECTIVES

We aimed to obtain information about the characteristics of the ICUs in our country via a point prevalence study.

MATERIAL AND METHODS

This cross-sectional study was planned by the Respiratory Failure and Intensive Care Assembly of Turkish Thoracic Society. A questionnaire was prepared and invitations were sent from the association's communication channels to reach the whole country. Data were collected through all participating intensivists between the October 26, 2016 at 08:00 and October 27, 2016 at 08:00.

RESULTS

Data were collected from the 67 centers. Overall, 76.1% of the ICUs were managed with a closed system. In total, 35.8% (n=24) of ICUs were levels of care (LOC) 2 and 64.2% (n=43) were LOC 3. The median total numbers of ICU beds, LOC 2, and LOC 3 beds were 12 (8-23), 14 (10-25), and 12 (8-20), respectively. The median number of ventilators was 12 (7-21) and that of ventilators with non-invasive ventilation mode was 11 (6-20). The median numbers of patients per physician during day and night were 3.9 (2.3-8) and 13 (9-23), respectively. The median number of patients per nurse was 2.5 (2-3.1); 88.1% of the nurses were certified by national certification corporation.

CONCLUSION

In terms of the number of staff, there is a need for specialist physicians, especially during the night and nurses in our country. It was thought that the number of ICU-certified nurses was comparatively sufficient, yet the target was supposed to be 100% for this rate.

Day-Time Isoflurane Administration Suppresses Circadian Gene Expressions in Both the Brain and a Peripheral Organ, Liver

OBJECTIVE

The aim of this study is to investigate the effects of light and administration time of isoflurane on circadian gene expression in the brains and liver tissues of rats kept in light-dark cycle.

METHODS

Seventy two 15-days-old rats pups were divided into four groups. All animals were exposed to 1.5% concentration of isoflurane or to 6 L min^-1 O₂ for six hours between Zeitgeber Time (ZT) 0-ZT06 (day-time administration) or ZT12-ZT18 (night-time administration). Rats were sacrificed after six hours of anaesthesia with four-hour time intervals. Total RNA was isolated from brains and liver tissues. Circadian gene expression was examined using quantitative real-time Reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

BMAL1, CLOCK, PER2 and CRY2 gene expression levels were markedly suppressed after day-time anaesthesia in the both brain and liver, but night-time administration caused only temporary suppression of gene expression.

CONCLUSION

The effect of isoflurane on the circadian clock is time-dependent, and administered isoflurane anaesthesia at night had minimal effect on clock gene expression. Additionally, when the treated animals were kept in a regular light-dark cycle, isoflurane-induced phase shift was not observed, possibly because of the light.

Trait-related alterations of N-acetylaspartate in euthymic bipolar patients: A longitudinal proton magnetic resonance spectroscopy study

BACKGROUND

Neurochemical changes are responsible for bipolar disorder (BD) pathophysiology. Despite current progress in BD research, mood- and trait-related alterations in BD continue to elicit further investigation.

METHODS

In this study, we report a longitudinal proton magnetic resonance spectroscopy study evaluating dorsomedial prefrontal cortex (DMPFC) metabolites N-acetylaspartate (NAA), creatine plus phosphocreatine (total creatine [tCr]), phosphorylcholine plus glycerophosphocholine, myo-inositol, and glutamate plus glutamine levels of manic and euthymic adult BD type I patients (n=48) treated with standard antimanic medicines, compared to matching healthy controls (n=44).

RESULTS

DMPFC NAA values and NAA/tCr ratio were significantly lower in euthymic BD patients when compared with healthy controls with similar levels of other metabolites in all groups, indicating a trait-related NAA abnormality in euthymic BD patients.

LIMITATIONS

of our study include a relatively low (1.5T) magnetic resonance field strength and variable drugs administered to achieve euthymia despite the best efforts to standardize the open fashion treatment.

CONCLUSIONS

Our study contributes to the integrating models of trait-related metabolite alterations observed in euthymia since NAA is considered as a marker of neuronal viability and mitochondrial energy metabolism. In light of supporting and conflicting results reported previously, future studies with longitudinal designs and larger patient groups are warranted to better define both state- and trait-related cerebral metabolic alterations associated with BD pathophysiology.

Analyzing Exposures to Electromagnetic Fields in an Intensive Care Unit

OBJECTIVE

In this study, we conducted a numerical analysis of exposure to electromagnetic fields (EMFs) in a hospital's intensive care unit that is one of the most crucial one in terms of hazardous areas among all service units. This is a new study for measuring exposure to EMFs in an intensive care unit as well as other healthcare services in Turkey.

METHODS

We measured the EMFs in the intensive care unit with a SRM-3006 (selective radiation metre), which was used for measurement of the absolute and the limit values of high frequency EMFs. The measurement points were chosen to represent the highest levels of exposure to which a person might be subjected. We obtained a dataset that included 5929 observations, with 96 extreme values, through measuring the magnetic field in terms of V/m.

RESULTS

The measurements show the frequency varies from 47 MHz to 2.5 GHz as 17 frequency ranges at the measurement point as well. According to these findings, the referenced maximum safety limit was not exceeded. However, it was also found that mobile telecommunication was the most critical cause of magnetic fields.

CONCLUSION

Further studies need to be performed with different frequency antennas to assess the EMFs in intensive care units.

Hemostatic efficacy of local chitosan linear polymer granule in an experimental sheep model with severe bleeding of arteria and vena femoralis

BACKGROUND

The aim of the present study was to evaluate the hemostatic effect of chitosan linear polymer in a sheep model with femoral bleeding.

METHODS

Following induction of anesthesia and intubation of sheep, groin injury was induced to initiate hemorrhage. Animals were randomly assigned to study and control groups. In the control group, absorbent pads were packed on the wound, and pressure was supplied by a weight placed over the dressing. In the study group, chitosan linear polymer was poured onto the bleeding site; absorbent pads and pressure were applied in the same manner. At 5-min intervals, bleeding was evaluated. Primary endpoint was time to hemostasis.

RESULTS

Bleeding had stopped by the 1st interval in 5 members of the study group, and by the 2nd interval in 1 member. One sheep was excluded. The bleeding stopped after the 1st interval in 1 member of the control group and after the 2nd interval in 4 members. Bleeding stopped in 2 cases following ligation of the bleeding vessel. Hemostasis was achieved earlier in the study group, compared to the control group, and the difference was statistically significant.

CONCLUSION

Hemostasis was achieved earlier following application of chitosan linear polymer.

The effects of intra-cerebroventricular administered rocuronium on the central nervous system of rats and determination of its epileptic seizure-inducing dose

BACKGROUND

The aim of this study was to investigate the effects of intracerebroventricularly administered rocuronium bromide on the central nervous system, determine the seizure threshold dose of rocuronium bromide in rats, and investigate the effects of rocuronium on the central nervous system at 1/5, 1/10, and 1/100 dilutions of the determined seizure threshold dose.

METHODS

A permanent cannula was placed in the lateral cerebral ventricle of the animals. The study was designed in two phases. In the first phase, the seizure threshold dose of rocuronium bromide was determined. In the second phase, Group R 1/5 (n=6), Group 1/10 (n=6), and Group 1/100 (n=6) were formed using doses of 1/5, 1/10, and 1/100, respectively, of the obtained rocuronium bromide seizure threshold dose.

RESULTS

The rocuronium bromide seizure threshold value was found to be 0.056±0.009μmoL. The seizure threshold, as a function of the body weight of rats, was calculated as 0.286μmoL/kg^-1. A dose of 1/5 of the seizure threshold dose primarily caused splayed limbs, posturing, and tremors of the entire body, whereas the dose of 1/10 of the seizure threshold dose caused agitation and shivering. A dose of 1/100 of the seizure threshold dose was associated with decreased locomotor activity.

CONCLUSIONS

This study showed that rocuronium bromide has dose-related deleterious effects on the central nervous system and can produce dose-dependent excitatory effects and seizures.

Antimanic Treatment With Tamoxifen Affects Brain Chemistry: A Double-Blind, Placebo-Controlled Proton Magnetic Resonance Spectroscopy Study

BACKGROUND

The antimanic efficacy of a protein kinase C (PKC) inhibitor, tamoxifen, has been tested in several clinical trials, all reporting positive results. However, mechanisms underlying the observed clinical effects requires further confirmation through studies of biological markers.

METHODS

We investigated the effect of tamoxifen versus placebo on brain metabolites via a proton (¹H) magnetic resonance spectroscopy (MRS) study. Forty-eight adult bipolar I manic patients (mean Young Mania Rating Scale (YMRS) score of 37.8±5.8) were scanned at baseline and following 3 weeks of double-blind treatment. We hypothesized that manic symptom alleviation would improve the levels of markers associated with brain energy metabolism (creatine plus phosphocreatine [total creatine; tCr]) and neuronal viability (N-acetylaspartate [NAA]).

RESULTS

The YMRS scores decreased from 38.6±4.5 to 20.0±11.1 in the tamoxifen group and increased from 37.0±6.8 to 43.1±7.8 in the placebo group (p<0.001). ¹H MRS measurements revealed a 5.5±13.8% increase in the dorsomedial prefrontal cortex (DMPFC) tCr levels in the tamoxifen group and a 5.3±13.1% decrease in tCr in the placebo group (p=0.027). A significant correlation between the YMRS score change and tCr percent change was observed in the whole group (Spearman ρ=0.341, p=0.029). Both tCr and NAA levels in the responder group were increased by 9.4±15.2% and 6.1±11.7%, whereas levels in the non-responder group were decreased by 2.1±13.2% and 6.5±10.5%, respectively (p<0.05).

CONCLUSIONS

Tamoxifen effectively treated mania while it also increased brain tCr levels, consistent with involvement of both excessive PKC activation and impaired brain energy metabolism in the development of bipolar mania.

CLINICAL TRIAL REGISTRATION

Registry name: ClinicalTrials.gov URL: https://clinicaltrials.gov/ct2/show/NCT00411203?term=NCT00411203&rank=1 Registration number: NCT00411203.

Cardioprotective Effects of Remifentanil in a Sympathetic Hyperactivity Model in Rabbits

OBJECTIVE

In this study, the antiarrhythmic and anti-ischemic effects of a 6 μg kg(-1) min(-1) infusion dose of remifentanil are investigated in a central sympathetic hyperactivity model in rabbits.

METHODS

In this study, 18 New Zealand rabbits were used. The subjects were randomly divided into three groups (n=6) and received 10 μmol L(-1) glutamate intracerebroventricularly to provide the central sympathetic hyperactivity. In group 1, 10 μmol L(-1) glutamate was used; in group 2, 1 h before L-glutamate injection, 40 mg kg(-1) N (omega)-nitro-L-arginine methyl ester was intravenously (iv) administered; and in group 3, also 1 h before L-glutamate injection, 40 mg kg(-1) N (omega)-nitro-L-arginine methyl ester was iv administered. A 6 μg kg(-1) min(-1) dose of remifentanil infusion was administered 5 min before L-glutamate injection. Heart rate, systolic arterial pressure and mean arterial pressure were measured and recorded. Within 15 min of the intracerebroventricular L-glutamate injection, premature ventricular complexes, bigeminy ventricular arrhythmia, ventricular tachycardia, ST-segment shift and T-wave inversions were recorded.

RESULTS

When incidences of heart rate, rate pressure product, premature ventricular complexes and bigeminy ventricular arrhythmia were compared between groups, significant differences were not determined. Mean arterial pressure was more significantly increased in group 2 than in the other groups (p<0.05). Ventricular tachycardia, ST-segment shift and T-wave inversions were significantly lower in group 3 than in groups 1 and 2 (p<0.05).

CONCLUSION

Remifentanil (6 μg kg(-1) min(-1) for 5 min of infusion) prevented life-threatening ventricular tachycardia and electrocardiographic signs of myocardial ischemia in a model of arrhythmia resulting from the association of central sympathetic overactivity.

Otoprotective effect of recombinant erythropoietin in a model of newborn hypoxic-ischemic encephalopathy

OBJECTIVE

The aim of this study is to test the hypotheses that central auditory pathology as well as inner ear pathology is contributing mechanisms to observed hypoxic-ischemic encephalopathy (HIE) induced hearing loss and that recombinant erythropoietin (rhEPO) will reduce this cellular pathology and attenuate hearing loss.

METHODS

Twenty-eight 7-day Wistar albino rat pups were divided into four groups: Control group (n=8) was given only intraperitoneal saline solution. Sham group (n=5) had only a midline neck incisions without carotid ligation under general anesthesia and administration of intraperitoneal saline solution. HIE group (n=8) and rhEPO treated group (n=7) were subjected to left common carotid artery ligation followed by 2.5h hypoxia exposure to a mixture of 8% oxygen and 92% pure nitrogen. HIE group was injected with intraperitoneal saline solution, while the rhEPO treated group received rhEPO 100 U/kg within the same volume as the saline-alone solution. At the end of the seventh week of age hearing (ABRs) was evaluated in response to clicks, 6 kHz and 8 kHz tone burst stimuli. Animals were sacrificed and both temporal lobes, cochleas and brainstems of the animals were collected. Tissue samples were evaluated with light microscopy, immunohistochemical studies, including TUNEL and caspase-3 stainings, and electron microscopy.

RESULTS

Hearing thresholds were elevated in HIE animals. In rhEPO treated animals, ABR values were similar to controls. HIE caused apoptotic changes in brainstem structures as shown by light microscopy and immunohistochemical methods. Apoptotic changes also were found within the organ of Corti, spiral ganglion cells and neurons of temporal lobe by electron microscopic investigation. In rhEPO animals many of these apoptotic changes were observed, but reduced compared to untreated animals.

CONCLUSIONS

Mechanisms underlying HIE-induced hearing loss are based on apoptosis in inner ear; however central auditory pathway pathology occurs as well, likely contributing to changes in auditory processing and perception of complex signals not reflected by the ABR threshold shifts. For both clinical and basic significance 'rhRPO' is found to reduce those effects.

Postoperative visual impairment after spinal fusion surgery

OBJECTIVE

The aim of this prospective study was to detect risk factors for visual impairment or changes in vision following spinal fusion surgery.

METHODS

A total of 68 patients aged 18-65 years, scheduled for posterior spinal fusion surgery, were included. Ophthalmic examinations were performed by an ophthalmologist on the day before surgery and repeated after the second postoperative day, within the first postoperative week. Patient characteristics were compared according to two clinical outcomes following surgery: worsening of vision during the pre- and postoperative interval (group 1) and no change in pre- and postoperative examinations (group 2).

RESULTS

The mean age of patients with postoperative visual changes was significantly higher than that for patients without postoperative visual changes. Total number of female patients and use of intraoperative ephedrine to treat hypotensive episodes were significantly higher in group 1 than in group 2 patients.

CONCLUSION

Older age, female gender and intraoperative hypotensive episodes are potential risk factors for postoperative visual impairment in patients who have undergone spinal fusion surgery.

In vivo proton magnetic resonance spectroscopic examination of benzodiazepine action in humans

In an examination of the effect of benzodiazepines on brain chemistry, 44 healthy controls underwent a short echo-time proton magnetic resonance spectroscopy ((1)H MRS) session after induced sedation with intravenous midazolam (0.03mg/kg) plus fentanyl (2μg/kg). The regions of interest were the anterior cingulate cortex, right basal ganglia, right frontal lobe, and right hippocampus. Twenty-five of these subjects underwent the second (1)H MRS session while awake. The measured (1)H MRS metabolites included N-acetyl-aspartate, creatine-containing compounds (PCr+Cr), choline-containing compounds, myo-inositol, and glutamate plus glutamine, which were quantified both as absolute values and metabolite/PCr+Cr ratios. The results were analyzed using independent group t tests and repeated measures analysis of variance (ANOVA, with alpha values set at 0.025 to minimize the risk of false-positive findings arising from multiple comparisons. No significant difference between subjects under midazolam plus fentanyl induced sedation and awake could be detected with unpaired analyses. Paired comparisons by ANOVA with repeated measures found that neither drug (midazolam plus fentanyl) nor the drug by time (interval between two scan times) interaction had a significant effect on the quantified metabolites. These findings encourage utilization of benzodiazepine-induced brief sedation during in vivo (1)H MRS experiments of the brain, and may help with elucidation of state-dependent neurochemical alterations during the course of bipolar and schizoaffective disorders.

The role of cobalt-albumin binding analysis in the diagnosis of experimental abdominal compartment syndrome in rabbits

BACKGROUND

The purpose of our study was to examine the role of cobalt-albumin binding assay (CABA) for the early diagnosis of abdominal compartment syndrome (ACS).

METHODS

Twenty-four anesthetized and ventilated rabbits were randomly assigned to four groups as 1 to 4, with each group comprised of six animals. Intraabdominal hypertension of 25 mmHg was induced for 15, 30, 45, and 60 minutes by insufflation in the four groups, respectively. Five ml of blood was drawn from each animal before the animals were sacrificed. A CABA test was performed on the samples and results were compared with pathologic diagnosis of intestinal samples shown as a score of damage severity values.

RESULTS

Ischemia-modified albumin (IMA) in Group 4 was significantly higher than in Group 1 and Group 2 (0.65 ± 0.16, 0.60 ± 0.25 and 0.61 ± 0.14, respectively; p < 0.05). However, there was no significant difference between the IMA of Group 3 and Group 4. Score of damage severity values reached statistically significant levels in Group 4 compared with Group 1 and Group 2 (p < 0.004 and 0.006, respectively) and in Group 3 compared with Group 1 (p < 0.004). There was also a statistically significant difference between Groups 1 and 2 (p < 0.004).

CONCLUSION

CABA plays an important role in the early diagnosis of ACS at the beginning of intestinal ischemia.

Erythropoietin attenuates neuronal injury and potentiates the expression of pCREB in anterior horn after transient spinal cord ischemia in rats

BACKGROUND

Recent studies have suggested that EPO activates the CREB transcription pathway and increases BDNF expression and production, which contributes to EPO-mediated neuroprotection. We investigated whether EPO has a neuroprotective effect against ISCI in rats and examined the involvement of CREB protein phosphorylation in this process.

METHODS

Spinal cord ischemia was produced by balloon occlusion of the abdominal aorta below the branching point of the left subclavian artery for 5 minutes, and rHu-EPO (1000 U/kg BW) was administered intravenously after the onset of the reperfusion. Neurologic status was assessed at 1, 24, and, 48 hours. After the end of 48 hours, spinal cords were harvested for histopathologic analysis and immunohistochemistry for pCREB.

RESULTS

All sham-operated rats had a normal neurologic outcome, whereas all ischemic rats suffered severe neurologic deficits after ISCI. Erythropoietin treatment was found to accelerate recovery of motor deficits and prevent the loss of motoneurons in the spinal cord after transient ischemia. Ischemic spinal cord injury induced the phosphorylation of pCREB at the anterior horn of the spinal cord, and EPO treatment significantly potentiated expression of pCREB increase at the anterior horn of the spinal cord.

CONCLUSIONS

These results demonstrate that a single dose of EPO given before ISCI provides significant neuroprotection and potentiates the expression of pCREB in this region.

Erythropoietin protects against necrotizing enterocolitis of newborn rats by the inhibiting nitric oxide formation

BACKGROUND

Necrotizing enterocolitis (NEC) is an important neonatal disease with a high mortality rate; erythropoietin (Epo) is a hematopoietic growth factor. Functional Epo receptors are in the fetal and postnatal small bowel and their ligands are available for binding. Excessive nitric oxide (NO) production by an isoform of NO synthase inducible by inflammatory stimuli leads to changes in vascular permeability and tissue injury. The aim of this study was to investigate NO formation in an experimental model of NEC and the possible role of NO in the protection Epo provides against NEC.

METHODS

Twenty-four Wistar albino rat pups were divided into three groups: group 1 = control; group 2 = hypoxia-reoxygenation and saline; group 3 = hypoxia-reoxygenation and recombinant human EPO (rhEpo) pretreatment. rhEpo was given 750 U/kg/week by intraperitoneal injection 3 times a week for 2 weeks. On the 15th day, hypoxia was induced by placing the pups in a 100% CO(2) chamber for 5 min. After the hypoxia period the pups were reoxygenated for 10 min with 100% O(2) and returned to their mothers. All pups were killed 4 h after the hypoxia-reoxygenation period was over. The abdomen was opened and representative samples of injured areas were taken for histopathologic examination. Then nitrite levels were determined in the intestine by Griess Reagent.

RESULTS

On histopathological examination, injury scores in group-2 animals were found to be significantly higher than in group-3 animals (p = 0.001). Significantly increased intestinal nitrite levels were found in group-2 rats compared to the rats of groups 1 and 3 (p = 0.001 and p = 0.001, respectively). There was a positive correlation between the histological findings and the intestinal nitrite levels in group-2 and -3 animals (r = 0.94, p = 0.001; r = 0.99, p = 0.001, respectively).

CONCLUSION

The present study demonstrates that the Epo-pretreated group had decreased levels of NO and limited mucosal necrosis in intestinal tissue samples. We believe that these results deserve further experimental studies in order to elucidate the possible effector mechanisms involved in the inhibitory relationship between Epo, NO and NEC.

Practices of anaesthesiologists with regard to withholding and withdrawal of life support from the critically ill in Turkey

BACKGROUND

To determine practices of Turkish anaesthesiologists with regard to withholding and withdrawal of life support from the critically ill.

METHODS

An anonymous questionnaire consisting of 18 questions was mailed to 439 members of the Turkish Society of Anaesthesiology and Reanimation.

RESULTS

Three hundred and 69 questionnaires were returned (84% response). Over 90% of the respondents indicated that they were Muslim. We found that 66% of respondents had initiated written or oral do-not-resuscitate orders, most frequently after discussion with colleagues (82%).

CONCLUSIONS

While a number of similarities were found between Turkish anaesthesiologists and those from other countries, some specific differences could be identified, particularly related to consensus decision-making and sharing information with other providers and the value of Ethics Committees in the decision-making process.

Antinociceptive and neurotoxicologic screening of chronic intrathecal administration of ketorolac tromethamine in the rat

Many drugs are tested intrathecally to investigate alternatives to opioids. We aimed to explore the analgesic and possible neurotoxic effects of chronic intrathecally-administered ketorolac tromethamine in rats. Catheters were placed via atlantoaxial interval in 28 Wistar rats under anesthesia of intraperitoneally-injected thiopental 30 mg/kg. Rats were randomized into 4 groups and administered 4 repeated intrathecal doses of therapy with 5-day intervals. The control group received 10 microL of saline, and the other groups received 50, 150, and 400 microg of ketorolac tromethamine respectively. The formalin test, behavioral test, and histopathological examination of four different spinal cord levels were performed. Neither behavioral testing nor histopathological examination revealed abnormalities that would suggest neurotoxicity. Formalin tests showed that both phase I and phase II responses of ketorolac tromethamine groups were significantly less than those of the control group. Although phase I responses did not differ during comparisons among ketorolac tromethamine-administered groups, phase II responses decreased significantly in groups that received 150 and 400 microg of ketorolac tromethamine. Intrathecally administered ketorolac tromethamine reduced nociceptive responses and exhibited no untoward neurological effect even at large doses. However, its intrathecal use as a safe alternative drug for chronic pain remains to be investigated in other species.

IMPLICATIONS

The present study is unique because it has demonstrated that chronic intrathecal administration of ketorolac tromethamine in rats, even at considerably large doses, showed a potent analgesic effect during the formalin test without exhibiting any neurotoxic side effect.

Erythropoietin is a multifunctional tissue-protective cytokine

Erythropoietin (EPO) was originally identified as a hormone produced by the adult kidney to facilitate optimum delivery of oxygen to tissue beds by adjustment of the circulating erythrocyte mass. The cloning of the EPO gene, subsequent production of recombinant protein, and successful introduction into clinical practice for the treatment of the anemia of renal failure is a triumph of biotechnology. However, molecular biologic studies have established that EPO is a member of the cytokine superfamily, with significant homology to mediators of growth and inflammation. Therefore, it is not surprising that additional biologic functions for this protein have been identified. Results from studies have shown that EPO and its receptor are widely expressed in embryonic and adult tissues, including the central nervous system, gut, kidney, muscle (eg, smooth, skeletal, and heart), uterus, retina, pancreas, gonads, and lung. We review the evidence that EPO and its receptor function as a paracrine/autocrine system to mediate the protection of tissues subjected to metabolic stress.

Effects of pressure- and volume-controlled inverse ratio ventilation on haemodynamic variables, intracranial pressure and cerebral perfusion pressure in rabbits: a model of subarachnoid haemorrhage under isoflurane anaesthesia

BACKGROUND AND OBJECTIVE

An inverse I : E ratio (inspiratory time > expiratory time) may have benefits in patients suffering trauma who requiring lung ventilation. However, this application may be deleterious if there is concomitant head injury. We aimed to determine the physiological effects of pressure- and volume-controlled modes of inverse ratio (I : E = 2 : 1) ventilation of the lungs, while maintaining normocapnia, in a rabbit model of raised intracranial pressure (ICP).

METHODS

New Zealand White rabbits were anaesthetized with isoflurane and a tracheostomy was performed. Subarachnoid haemorrhage was simulated in two groups by injecting blood into the cisterna magna. Groups 1 and 2 (n = 6, each), controls, were compared with Groups 3 and 4 (n = 6, each) with the simulated subarachnoid haemorrhage. Each ventilation mode was used with an I : E ratio of 2 : 1 for 30 min. Mean arterial pressure (MAP), ICP, cerebral perfusion pressure (CPP), mean airway pressure (P(AW)) and arterial blood-gas status were measured.

RESULTS

Both modes increased mean P(AW) (P < 0.02). This increase was greater with the volume-controlled mode (P < 0.02). The baseline value averaged 5.8 +/- 0.4 and 5.6 +/- 0.3 mmHg in Groups 3 and 4, respectively, and increased to 7.8 +/- 0.3 and 10.8 +/- 0.4 mmHg. Inducing subarachnoid haemorrhage increased ICP and MAP (P < 0.02). Baseline ICPs were 10.3 +/- 0.5 and 10.3 +/- 0.4 mmHg in Groups 1 and 2, respectively, whereas they were 25.4 +/- 1.2 and 25.8 +/- 0.8 mmHg in Groups 3 and 4. However, ICP, MAP and CPP did not differ significantly according to the mode.

CONCLUSIONS

An already raised ICP was altered by the application of induced mean PAW increases as a consequence of inverse ratio ventilation of the lungs with normocapnia.

EMLA does not permit pain-free retrobulbar injection

BACKGROUND

Retrobulbar injection can be associated with significant pain, due to both needle insertion and deposition of the local anaesthetic solution. The local anaesthetic cream EMLA (eutectic mixture of local anaesthetics) which contains a mixture of lignocaine and prilocaine has been shown to reduce the pain associated with skin puncture. The efficacy of EMLA in alleviating the pain of retrobulbar injection for cataract surgery was assessed in this study.

METHODS

In this, randomised double-blind study, EMLA (n = 53) or lignocaine 5% ointment (n = 50) was administered to the inferior orbital margin at least 45 min before retrobulbar block in 103 patients. Pain assessed during retrobulbar block was marked subjectively by the patient on a 10-point numerical rating scale.

RESULTS

Median verbal pain scores were 3.0 with an interquartile range of 1.5-6.5 in the control group and 3.50 with an interquartile range of 2.0-6.0 in the EMLA(R) group (P = 0.67). There was no significant difference between the EMLA group and the lignocaine ointment group according to this pain assessment.

CONCLUSION

EMLA does not permit pain-free retrobulbar injection.

Effects of normovolaemic haemodilution on middle cerebral artery blood flow velocity and oxygen delivery

BACKGROUND AND OBJECTIVE

Assessment of the effects of normovolaemic haemodilution on middle cerebral artery blood flow velocity with transcranial Doppler ultrasonography, intracranial pressure, cerebral perfusion pressure, arterial oxygen content and cerebral oxygen delivery.

METHODS

Normovolaemic haemodilution was induced in rabbits under general anaesthesia, and the haematocrit was allowed to decrease to 30% in Group 1 (n = 6) and to 20% in Group 2 (n = 6). Peak systolic and diastolic velocities, mean blood flow velocity, and pulsatility and resistance indices of the middle cerebral artery were measured by transcranial Doppler ultrasonography. Changes in intracranial pressure, cerebral perfusion pressure, arterial oxygen content and cerebral oxygen delivery were also assessed.

RESULTS

In Group 2, middle cerebral artery blood flow velocity increased from 0.4 +/- 0.01 to 0.51 +/- 0.02 m s(-1) after the induction of normovolaemic haemodilution (P = 0.04), while arterial oxygen content decreased from 16.2 +/- 0.1 to 8.5 +/- 0.1 mLdL(-1) (P = 0.002). The decrease in cerebral oxygen delivery from 6.5 +/- 0.2 to 4.3 +/- 0.2 was also significant (P = 0.02). However, no associated changes in intracranial pressure and cerebral perfusion pressure could be demonstrated.

CONCLUSIONS

Normovolaemic haemodilution resulted in an increase in the mean blood flow velocity of the middle cerebral artery. However, this increase did not compensate for the consequences of the altered oxygen delivery to the brain when the haematocrit was reduced to 20%.

Erythropoietin prevents motor neuron apoptosis and neurologic disability in experimental spinal cord ischemic injury

The cytokine erythropoietin (EPO) possesses potent neuroprotective activity against a variety of potential brain injuries, including transient ischemia and reperfusion. It is currently unknown whether EPO will also ameliorate spinal cord injury. Immunocytochemistry performed using human spinal cord sections showed abundant EPO receptor immunoreactivity of capillaries, especially in white matter, and motor neurons within the ventral horn. We used a transient global spinal ischemia model in rabbits to test whether exogenous EPO can cross the blood-spinal cord barrier and protect these motor neurons. Spinal cord ischemia was produced in rabbits by occlusion of the abdominal aorta for 20 min, followed by saline or recombinant human (rHu)-EPO (350, 800, or 1,000 units/kg of body weight) administered intravenously immediately after the onset of reperfusion. The functional neurological status of animals was better for rHu-EPO-treated animals 1 h after recovery from anesthesia, and improved dramatically over the next 48 h. In contrast, saline-treated animals exhibited a poorer neurological score at 1 h and did not significantly improve. Histopathological examination of the affected spinal cord revealed widespread motor neuron injury associated with positive terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling in control but not in rHu-EPO-treated animals. These observations suggest both an acute as well as a delayed beneficial action of rHu-EPO in ischemic spinal cord injury. Because rHu-EPO is currently used widely with an excellent safety profile, clinical trials evaluating its potential to prevent motor neuron apoptosis and the neurological deficits that occur as a consequence of ischemic injury are warranted.

Intracranial penetrating injury associated with an intraoperative epidural haematoma caused by a spring-laden pin of a multipoise headrest

Lack of an intermediary piece that should have been placed between the pin and spring resulted in skull penetration due to a rapid waste in the spring's compensatory capacity. Checking integrity of internal pieces should be performed regularly. Designing intermediary piece and spring as a single piece might increase safety.