Recurrences in Sudden Sensorineural Hearing Loss: A Long-Term Observational Study.

Purpose Long-term outcomes of sudden sensorineural hearing loss (SSNHL) are poorly studied. The recurrence rate is heterogeneous, and the prognosis of relapses is uncertain. The aim of this retrospective study was to evaluate the recurrence rate of SSNHL and to analyze the correlation with clinical and audiometric characteristics. Method Seventy-three patients with idiopatic SSNHL were evaluated. Clinical and audiometric features were recorded. Seventy patients (95.8%) had at least a 2-year follow-up, whereas 50 (68.4%) had a 5-year follow-up. Results Two- and 5-year recurrence rates were 5.60% and 10.34%, respectively. Mean time lapse between 1st episode and recurrence was 29.33 ± 26.60 months. About 70% of patients had a partial recovery at recurrence. The same ear was affected in 42.8% of patients, the contralateral ear was affected in 42.8% of patients, and recurrence was bilateral in 14.4% of cases. Recurrence correlated only with the presence of tinnitus during follow-up. However, the small number of participants with recurrence represented a limiting factor of our study. Conclusions Recurrences of SSNHL are rare events that can involve ipsilateral or contralateral ear. Further studies are necessary to identify predictors of recurrence.

Successful Management of Severe Bromethalin Toxicosis in a Dog.

ABSTRACT The use of bromethalin rodenticides has risen since 2011, and in some states, it is the most common rodenticide ingestion reported to poison control. Although intravenous lipid emulsion (ILE) has been previously reported to lower serum desmethylbromethalin levels in an asymptomatic dog, and repeated mannitol has been investigated in a laboratory setting, there are no published reports of successful treatment of symptomatic bromethalin toxicosis in dogs. A 9 yr old castrated male Norwich terrier was evaluated for obtunded mentation, seizures, cranial nerve deficits, and tetraparesis secondary to bromethalin toxicosis. The patient was treated with ILE, mannitol, and ginkgo biloba and returned to normal neurological function. Bromethalin exposure was confirmed by serum desmethylbromethalin levels. Previous literature indicates that the prognosis for patients who suffer from symptomatic bromethalin toxicosis is poor to grave, and the return to normal neurological function after severe toxicosis has not been reported. ILE, mannitol, and ginkgo biloba are readily available and relatively inexpensive, and in combination may be of benefit in symptomatic bromethalin intoxication.

A dose-response relationship study of hypertonic saline on brain relaxation during supratentorial brain tumour craniotomy.

Background: A prospective, randomized, double-blind study was designed to assess differences in brain relaxation between 2 doses of 3% HS during elective supratentorial brain tumour surgery.Methods: 60 patients undergoing supratentorial craniotomy for tumour resection were enrolled to receive either 3 mL/kg (group L) or 5 mL/kg (group H) of 3% HS administered at skin incision. Brain relaxation was assessed after dura opening on a scale ranging 1-4 (1 = perfectly relaxed, 2 = satisfactorily relaxed, 3 = firm brain, 4 = bulging brain). Hemodynamic variables and laboratory values (blood gases, osmolarity, haematocrit, and lactate) were collected before HS infusion and 30, 120 and 360 min after it. Presence of midline shift, postoperative complications, PCU and hospital stay, and mortality after 30 days were also recorded.Results: There was no difference in brain relaxation, with 2.0 (1.0-3.0) and 2.0 (1.0-2.3) (P = 0.535) for patients in groups L and H, respectively. If adjusted for the presence of midline shift, 50% of patients had adequate brain relaxation scores (grades 1 and 2) in group L and 61% in group H (OR 0.64, CI = 0.16-2.49, P = 0.515). No significant differences in perioperative outcome, mortality and length of PCU and hospital stay were observed.Conclusion: 3 mL/kg of 3% HS result in similar brain relaxation scores as 5 mL/kg in patients undergoing craniotomy for supratentorial brain tumour. This study reveals that both high and low doses of 3% HS may be less effective on intraoperative brain relaxation in patients with midline shift.

Impact of intestinal mannitol on hyperammonemia, oxidative stress and severity of hepatic encephalopathy in the ED.

Hyperammonemia results from hepatic inability to remove nitrogenous products generated by protein metabolism of intestinal microbiota, which leads to hepatic encephalopathy (HE) in chronic liver disease (CLD). In ammonium neurotoxicity, oxidative stress (OxS) plays a pathogenic role. Our objective was to evaluate if intestinal mannitol is as effective and safe as conventional treatment for diminishing hyperammonemia, OxS, and HE in patients with CLD. MATERIAL AND METHODS: We included 30 patients with HE classified by "Haven Criteria for Hepatic Encephalopathy". They were randomized into two groups: 1) Mannitol Group (MG) with mannitol 20% administered into the intestine by an enema, 2) conventional group (CG) with lactulose 40 g enema both substances were diluted in 800 mL of double distilled solution every 6 h; all patients received neomycin. We evaluated ammonia concentration, plasma oxidative stress, HE severity, intestinal discomfort and adverse effects. RESULTS: Hyperammonemia (171 ±â€¯104 vs 79 ±â€¯49 µmol ammonia/L, p < 0.01), and oxidative stress (MDA 29 vs 27%, formazan 15 vs 11%, carbonyls 16 vs 9% and dityrosines 10 vs 5%) were reduced in MG and CG respectively. The HE severity decreased by two degrees compared to baseline values in both groups. Intestinal discomfort and electrolyte plasma alterations were less frequent (p < 0.05) in MG than CG. CONCLUSIONS: Intestinal mannitol is as effective and safe as conventional treatment for reducing hyperammonemia, oxidative stress, and hepatic encephalopathy of CLD patients in the emergency room. Likewise, mannitol is better tolerated than conventional treatment.

Neuroprotective strategies for patients with acute myocardial infarction combined with hypoxic ischemic encephalopathy in the ICU.

BACKGROUND: We investigated neuroprotective treatment strategies for patients with acute myocardial infarction (AMI) complicated with hypoxic ischemic encephalopathy (HIE) in the ICU. METHODS: The 83 cases diagnosed with secondary AMI were, for the first time, divided into an observation group (n = 43) and control group (n = 40). All of the patients underwent emergency or elective PCI. Patients in the control group were treated with mannitol to reduce intracranial pressure and cinepazide maleate to improve microcirculation in the brain as well as given a comprehensive treatment with oxygen inhalation, fluid infusion, acid-base imbalance correction and electrolyte disturbance. Patients in the observation group underwent conventional treatment combined with neuroprotective therapeutic strategies. The effects of the different treatment strategies were compared. RESULTS: Consciousness recovery time, reflex recovery time, muscle tension recovery time and duration of ICU stay were significantly shorter in the observation group compared with the control group (P < 0.05). After treatment, the jugular vein oxygen saturation (SjvO2) and blood lactate (JB-LA) levels of both groups were lower than before treatment and the cerebral oxygen utilization rate (O2UC) increased, with a significantly higher increase in the observation group (P < 0.05). After treatment, the activities of daily living (ADL) score was higher for both groups and the neural function defect (NIHS) score was lower. CONCLUSION: The neuroprotective strategies of hypothermia and ganglioside administration assisted with hyperbaric oxygen was effective for treating AMI patients with HIE and may be worth clinical promotion.

Techniques for Learning Descemet Membrane Endothelial Keratoplasty for Eyes of Asian Patients With Shallow Anterior Chamber.

PURPOSE: To describe several essential surgical techniques that overcome difficulties in performing Descemet membrane endothelial keratoplasty (DMEK) for inexperienced surgeons, especially those who perform DMEK on eyes of Asian patients. METHODS: Nine eyes of 9 Asian patients with bullous keratopathy who underwent DMEK were analyzed retrospectively. All patients were given a diuretic such as D-mannitol or acetazolamide shortly before surgery, with retrobulbar anesthesia and a Nadbath facial nerve block. Core vitrectomy before DMEK was performed in several cases in which a high vitreous pressure during surgery was predicted. The donor graft was stained with trypan blue, and a 25-G anterior chamber maintenance cannula was used to maintain the anterior chamber depth during graft insertion in all eyes. RESULTS: The cornea became clear in all eyes. The best spectacle-corrected visual acuity had improved significantly 6 months after the surgery compared with preoperative values (P = 0.026). The corneal endothelial cell density was 1371 cells per square millimeter at postoperative 6 months. CONCLUSIONS: Although DMEK is technically difficult, especially for inexperienced surgeons who operate on eyes of Asian patients, controlling anterior chamber pressure using various manipulations may help to prevent iatrogenic primary graft failure and lead to successful DMEK.

Safety of a short hydration method for cisplatin administration in comparison with a conventional method-a retrospective study.

OBJECTIVE: Cisplatin is administered in combination with massive hydration to avoid renal toxicity, making its administration difficult in an outpatient setting. Although a short hydration protocol for cisplatin has been recently developed, its safety is not fully understood. METHODS: Consecutive patients with lung or other cancer and an Eastern Cooperative Oncology Group performance status of 0-2 who were receiving chemotherapy containing cisplatin at a dose of ≥60 mg/m(2) in a single administration were evaluated. Seventy-four patients were treated with a short hydration protocol consisting of 1750-2250 ml of hydration with mannitol and magnesium supplementation over a period of 3.75-4.75 h on Day 1. Sixty-nine patients were treated with a conventional hydration protocol consisting of 2100-2600 ml of hydration over 6.5-7.5 h on Day 1 with pre- and post-hydration on Days 0, 2 and 3. Toxicity was then compared between the two groups. RESULTS: An elevated serum creatinine level ≥grade 1 was significantly less frequent in the group receiving the short hydration protocol than in the group receiving conventional hydration. Other toxicities were similar between the two groups. Consequently, the completion rate for the planned treatment in the short hydration group (73.0%, 54/74) was significantly higher than that in the conventional hydration group (53.6%, 37/69). CONCLUSIONS: Short hydration is safe, making cisplatin-containing chemotherapy easier to perform.

Performance of two neutral oral contrast agents in CT enterography.

INTRODUCTION: This study compares the performance of two neutral oral contrast agents in CT enterography (CTE). Mannitol 2.5%, an oral osmotic agent, is compared with psyllium fibre (Metamucil). Both these agents are commonly used, but to our knowledge, they have not been compared in CTE. METHODS: CTE data were collected from 25 consecutive studies for both mannitol and psyllium fibre between 2011 and 2013. All images were reviewed by two radiologists and one registrar blinded to the oral contrast used. Each quadrant was assessed for maximum distension, proportion of bowel loops distended, presence of inhomogeneous content and bowel wall visibility. Overall subjective quality and whether the contrast agent reached the caecum were also assessed. Patients were invited to answer a questionnaire regarding tolerability of the preparations. RESULTS: Wall visibility was rated good in 100% of the mannitol studies, compared with 71% of the psyllium fibre studies, in the right lower quadrant (P = 0.01). No statistically significant difference between groups was observed in either maximal distension or proportion of loops distended in any quadrant. Inhomogeneous material was observed in 12% of the mannitol cases and 86% of the psyllium fibre cases (P < 0.0001). In all mannitol cases, the contrast reached the caecum, compared with 50% of psyllium fibre cases (P < 0.0001), and 36% of the mannitol studies were considered excellent, compared with 20% of the psyllium fibre studies (P = 0.03). CONCLUSION: Mannitol achieves studies of better quality and is now the preferred oral contrast for CTE studies at Auckland City Hospital.

Fluid volume kinetics of dilutional hyponatremia; a shock syndrome revisited.

OBJECTIVE: To evaluate whether the pathophysiology of shock syndromes can be better understood by comparing central hemodynamics with kinetic data on fluid and electrolyte shifts. METHODS: We studied the dilutional hyponatremic shock that developed in response to overhydration with electrolyte-free irrigating fluid - the so-called 'transurethral resection syndrome' - by comparing cardiac output, arterial pressures, and volume kinetic parameters in 17 pigs that were administered 150 ml/kg of either 1.5% glycine or 5% mannitol by intravenous infusion over 90 minutes. RESULTS: Natriuresis appeared to be the key factor promoting hypovolemic hypotension 15-20 minutes after fluid administration ended. Excessive sodium excretion, due to osmotic diuresis caused by the irrigant solutes, was associated with high estimates of the elimination rate constant (k10) and low or negative estimates of the rate constant describing re-distribution of fluid to the plasma after translocation to the interstitium (k21). These characteristics indicated a high urinary flow rate and the development of peripheral edema at the expense of plasma volume and were correlated with reductions in cardiac output. The same general effects of natriuresis were observed for both irrigating solutions, although the volume of infused 1.5% glycine had a higher tendency to enter the intracellular fluid space. CONCLUSION: Comparisons between hemodynamics and fluid turnover showed a likely sequence of events that led to hypovolemia despite intravenous administration of large amounts of fluid.

Fluid volume kinetics of dilutional hyponatremia; a shock syndrome revisited

OBJECTIVE: To evaluate whether the pathophysiology of shock syndromes can be better understood by comparing central hemodynamics with kinetic data on fluid and electrolyte shifts. METHODS: We studied the dilutional hyponatremic shock that developed in response to overhydration with electrolyte-free irrigating fluid - the so-called ‘transurethral resection syndrome' - by comparing cardiac output, arterial pressures, and volume kinetic parameters in 17 pigs that were administered 150 ml/kg of either 1.5% glycine or 5% mannitol by intravenous infusion over 90 minutes. RESULTS: Natriuresis appeared to be the key factor promoting hypovolemic hypotension 15-20 minutes after fluid administration ended. Excessive sodium excretion, due to osmotic diuresis caused by the irrigant solutes, was associated with high estimates of the elimination rate constant (k10) and low or negative estimates of the rate constant describing re-distribution of fluid to the plasma after translocation to the interstitium (k21). These characteristics indicated a high urinary flow rate and the development of peripheral edema at the expense of plasma volume and were correlated with reductions in cardiac output. The same general effects of natriuresis were observed for both irrigating solutions, although the volume of infused 1.5% glycine had a higher tendency to enter the intracellular fluid space. CONCLUSION: Comparisons between hemodynamics and fluid turnover showed a likely sequence of events that led to hypovolemia despite intravenous administration of large amounts of fluid. .

Mannitol increases renal blood flow and maintains filtration fraction and oxygenation in postoperative acute kidney injury: a prospective interventional study.

INTRODUCTION: Acute kidney injury (AKI), which is a major complication after cardiovascular surgery, is associated with significant morbidity and mortality. Diuretic agents are frequently used to improve urine output and to facilitate fluid management in these patients. Mannitol, an osmotic diuretic, is used in the perioperative setting in the belief that it exerts reno-protective properties. In a recent study on uncomplicated postcardiac-surgery patients with normal renal function, mannitol increased glomerular filtration rate (GFR), possibly by a deswelling effect on tubular cells. Furthermore, experimental studies have previously shown that renal ischemia causes an endothelial cell injury and dysfunction followed by endothelial cell edema. We studied the effects of mannitol on renal blood flow (RBF), glomerular filtration rate (GFR), renal oxygen consumption (RVO2), and extraction (RO2Ex) in early, ischemic AKI after cardiac surgery. METHODS: Eleven patients with AKI were studied during propofol sedation and mechanical ventilation 2 to 6 days after complicated cardiac surgery. All patients had severe heart failure treated with one (100%) or two (73%) inotropic agents and intraaortic balloon pump (36%). Systemic hemodynamics were measured with a pulmonary artery catheter. RBF and renal filtration fraction (FF) were measured by the renal vein thermo-dilution technique and by renal extraction of chromium-51-ethylenediaminetetraacetic acid (51Cr-EDTA), respectively. GFR was calculated as the product of FF and renal plasma flow RBF × (1-hematocrit). RVO2 and RO2Ex were calculated from arterial and renal vein blood samples according to standard formulae. After control measurements, a bolus dose of mannitol, 225 mg/kg, was given, followed by an infusion at a rate of 75 mg/kg/h for two 30-minute periods. RESULTS: Mannitol did not affect cardiac index or cardiac filling pressures. Mannitol increased urine flow by 61% (P < 0.001). This was accompanied by a 12% increase in RBF (P < 0.05) and a 13% decrease in renal vascular resistance (P < 0.05). Mannitol increased the RBF/cardiac output (CO) relation (P = 0.040). Mannitol caused no significant changes in RO2Ext or renal FF. CONCLUSIONS: Mannitol treatment of postoperative AKI induces a renal vasodilation and redistributes systemic blood flow to the kidneys. Mannitol does not affect filtration fraction or renal oxygenation, suggestive of balanced increases in perfusion/filtration and oxygen demand/supply.

Preparación para colonoscopia: tipos de productos y escalas de limpieza / Preparation for colonoscopy: types of scales and cleaning products

Una adecuada preparación del colon es fundamental antes de realizar una colonoscopia, ya que nos permite realizar una correcta exploración de toda la mucosa. El método ideal de limpieza del colon debe ser rápido, seguro y conseguir una limpieza apropiada con las mínimas molestias para el paciente. En la actualidad disponemos de una amplia variedad de productos de limpieza de colon, información que en ocasiones llega a ser confusa. Una buena preparación del colon depende por una parte de una correcta elección del mismo, pero también de una restricción dietética previa. El conocimiento de todos estos productos, con sus ventajas y limitaciones, nos permite hacer una mejor selección para cada paciente; y aunque la eficacia sea comparable, es la experiencia del explorador, las preferencias del paciente y el grado de cumplimiento de las instrucciones de preparación, las que influyen notablemente en los resultados(AU)

Adequate bowel preparation is essential before a colonoscopy, allowing us to make a proper examination of the entire mucosa. The ideal method of colon cleansing should be fast, safe, and get a proper cleaning with minimal discomfort for the patient. Today we have a wide variety of colon cleansing products, information sometimes becomes confused. A good colon preparation depends partly on correct choice of the same, but also upon dietary restriction. Knowledge of all these products, with their advantages and limitations, we can make a better selection for each patient, and although the efficacy is comparable, is the experience of the browser, patient preferences, and the degree of compliance with the instructions preparation, which greatly influence the results(AU)

Trial of Chinese medicine Wu-Ling-San for acute low-tone hearing loss.

PURPOSE: We used new criteria to elucidate the demographics of acute low-tone sensorineural hearing loss (ALHL) and tested the Chinese medicine Wu-Ling-San as a treatment for ALHL. PROCEDURES: We reviewed the medical records of patients with ALHL seen at the outpatient clinic of the Social Insurance Central General Hospital in Tokyo from April 2006 through August 2011. Patients were treated with an oral steroid, a diuretic, or Wu-Ling-San; alone or in combination. RESULTS: We identified 130 definite and 48 probable ALHL cases. The mean age and male-to-female ratio in probable cases were significantly higher than those in definite cases (p < 0.05). The steroid-Wu-Ling-San combination was significantly more effective (100% recovery) than the diuretic alone (59%), Wu-Ling-San alone (62%), or the steroid-diuretic combination (60%, p < 0.05). CONCLUSIONS: ALHL can develop in older patients more frequently than we expected. The steroid-Wu-Ling-San combination is a possible new treatment for ALHL.

Hydroelectrolytic balance and cerebral relaxation with hypertonic isoncotic saline versus mannitol (20%) during elective neuroanesthesia.

BACKGROUND AND OBJECTIVES: Cerebral relaxation during intracranial surgery is necessary, and hiperosmolar therapy is one of the measures used to this end. Frequently, neurosurgical patients have sodium imbalances. The objective of the present study was to quantify and determine cerebral relaxation and duration of hydroelectrolytic changes secondary to the use of mannitol versus hypertonic isoncotic solution (HIS) during neurosurgery. METHODS: Cerebral relaxation and hydroelectrolytic changes were evaluated in 29 adult patients before de beginning of infusion, and 30 and 120 minutes after the infusion of equiosmolar loads of approximately 20% mannitol (250 mL) or HIS (120 mL). The volume of intravenous fluids infused and diuresis were recorded. A p < 0.05 was considered significant. RESULTS: A statistically significant difference in cerebral relaxation between both groups was not observed. Although several changes in electrolyte levels and acid-base balance with mannitol or HIS reached statistical significance only the reduction in plasma sodium 30 minutes after infusion of mannitol, mean of 6.42 ± 0.40 mEq.L(-1), and the increase in chloride, mean of 5.41 ± 0.96 mEq.L(-1) and 5.45 ± 1.45 mEq.L(-1) 30 and 120 minutes after infusion of HIS, caused a transitory dislocation of serum ion levels from normal range. The mannitol (20%) group had a significantly greater diuresis at both times studied compared with HIS group. CONCLUSIONS: A single dose of hypertonic isoncotic saline solution [7.2% NaCl/6% HES (200/0.5)] and mannitol (20%) with equivalent osmolar loads were effective and safe in producing cerebral relaxation during elective neurosurgical procedures under general anesthesia.

Effect of the combination of mannitol and ringer acetate or hydroxyethyl starch on whole blood coagulation in vitro.

Mannitol is administered to decrease the intracranial pressure and to improve surgical conditions during craniotomy. Simultaneously a crystalloid infusion is always given and sometimes hydroxyethyl starch (HES) is indicated for intravascular volume replacement. As normal coagulation profile is required during craniotomy, we aimed at determining the effect of mannitol with or without HES or Ringer acetate on blood coagulation in this randomized cross-over in vitro study. Blood samples were withdrawn from 10 volunteers. From whole blood we prepared 10 vol.% and 20 vol.% dilutions of mannitol (15% Mannitol) alone, mannitol and Ringer acetate, and mannitol and HES 130/0.4 (Voluven) at a ratio of 1:1. Blood samples were analyzed by modified thromboelastometry. Coagulation parameters: clotting time, clot formation time, and maximum clot firmness (MCF), were registered. Clot formation time was prolonged in all dilutions compared with control (P<0.05). MCF decreased in all dilutions compared with control (P<0.05). MCF in 20 vol.% dilution of mannitol with HES was lower than MCF in the corresponding dilution with Ringer acetate (P<0.05). Fibrinogen-dependent MCF in 10 vol.% dilution of mannitol with HES was lower than MCF in the corresponding dilution with Ringer acetate (P<0.05). We conclude that mannitol in combination with HES 130/0.4 impairs clot propagation and clot strength in vitro. Fibrin clot strength impairment is more pronounced when mannitol is combined with HES than Ringer acetate. Our findings indicate that HES in combination with mannitol should be avoided whenever a disturbance in hemostasis is suspected during craniotomy.

Cystic fibrosis: a review of pulmonary and nutritional therapies.

In summary, there is a significant interplay between the pulmonary manifestations and nutritional status of CF patients. The advances in CF clinical care in the past 2 decades are mainly attributed to anti-infective therapy as well as aggressive nutritional management. Currently, there are multiple therapeutic agents that are in clinical trial that target either the underlying CFTR defect or the downstream effects of CFTR. The broad spectrum of therapeutic agents being studied as well as the advances in therapies that target the underlying CFTR defect are exciting, making it likely that at least one of the treatments will make a major difference in how we will treat CF in the future.

Monitoring of fluid absorption with nitrous oxide during transurethral resection of the prostate.

BACKGROUND: The fluid absorption that occurs during transurethral resection of the prostate (TURP) can be indicated and quantified by the ethanol method. Recently, nitrous oxide (N(2)O) was tested in animals and volunteers and seemed to be more accurate and safe. The present study compared these two methods in surgical patients. METHODS: Eighty-six TURPs were performed at two hospitals using an irrigating fluid that contained 3% mannitol, 1% ethanol and 0.004% N(2)O (40 ml/l). The ethanol concentration was measured by end-expiratory tests every 10 min. The N(2)O concentration was measured by a flared nasal cannula every second. Fluid absorption was calculated based on a regression equation (ethanol method) from the area under the curve based on the samples where CO(2) >median (N(2)O method). RESULTS: Thirteen patients (15%) absorbed >300 ml of fluid as indicated by the ethanol method. The median volume was 707 ml (range 367-1422). Ethanol yielded higher figures for fluid absorption up to 700-800 ml, whereafter the N(2)O method indicated that the absorption was larger. Over the entire range, the mean difference between the two methods at the end of any 10-min period of TURP was only +45 ml, although the 95% limits of agreement were quite separated (-479 to +569 ml). CONCLUSIONS: The N(2)O method does not require forced breath sampling and was successfully apply clinically. However, there was a dose-dependent difference in result between the ethanol and N(2)O methods, which markedly separated the limits of agreement for a wider range of fluid absorption events.

[Antiedematous effect of polyosm in rats with freezing lesion of brain].

Effect of the intravenous injection of polyosm (30% solution of polyethylene oxide with a molecular mass of 400, PEO-400) was investigated on Wistar rats with a model of brain edema induced by a freezing lesion in one cerebral hemisphere. The brain edema development was estimated by measuring the active resistance of tissues in the right and left parietal cortex and the content of water in both hemispheres. A course of the intravenous injections of polyosm (1 g/kg of PEO-400 daily during 3 days) after the model lesion onset decreased the initially elevated active resistance in the edematous cerebral tissue and reduced water accumulation in the damaged hemisphere.

Current controversies in the management of patients with severe traumatic brain injury.

BACKGROUND: Traumatic brain injury is a major cause of mortality and morbidity, particularly among young men. The efficacy and safety of most of the interventions used in the management of patients with traumatic brain injury remain unproven. Examples include the 'cerebral perfusion pressure-targeted' and 'volume-targeted' management strategies for optimizing cerebrovascular haemodynamics and specific interventions, such as hyperventilation, osmotherapy, cerebrospinal fluid drainage, barbiturates, decompressive craniectomy, therapeutic hypothermia, normobaric hyperoxia and hyperbaric oxygen therapy. METHODS: A review of the literature was performed to examine the evidence base behind each intervention. RESULTS: There is no class I evidence to support the routine use of any of the therapies examined. CONCLUSION: Well-designed, large, randomized controlled trials are needed to determine therapies that are safe and effective from those that are ineffective or harmful.

Role of pH in protection by low sodium against hypoxic injury in isolated perfused rat livers.

BACKGROUND/AIMS: The purpose of the present study was to characterize the role of Na+, pH and cellular swelling in the pathogenesis of hypoxic injury to rat livers. METHODS AND RESULTS: When livers were perfused with hypoxic Krebs-Henseleit bicarbonate buffer (KHB) containing 143 mM Na+, release of LDH began after 30 min and was maximal after 60 min. In livers perfused with choline-substituted low-Na+ KHB (25 mM Na+), LDH release began after 60 min and peaked after 120 min or longer. Supplementation of KHB with mannitol, a permeant sugar with antioxidant properties, suppressed LDH release, whereas sucrose, an impermeant disaccharide, did not afford protection. At the end of hypoxic perfusions with KHB and low-Na+ KHB, liver weight was not different, whereas mannitol but not sucrose increased liver weight after hypoxia. At pH 7.4, monensin, a Na+-H+ ionophore, reversed protection against hypoxia by low-Na+ KHB (10 mM Na+) but had no effect at pH 6.8. As measured directly by confocal microscopy of biscarboxyethylcarboxyfluorescein fluorescence, pH was lower during perfusion with low-Na+ KHB than KHB. CONCLUSIONS: Cytoprotection by low Na+ was not mediated by prevention of Na+-dependent tissue swelling. Rather, promotion of intracellular acidification likely mediates cytoprotection in low-Na+ buffer.