Single-dose lignocaine-based blood cardioplegia in single valve replacement patients

Abstract OBJECTIVE: Myocardial protection is the most important in cardiac surgery. We compared our modified single-dose long-acting lignocaine-based blood cardioplegia with short-acting St Thomas 1 blood cardioplegia in patients undergoing single valve replacement. METHODS: A total of 110 patients who underwent single (aortic or mitral) valve replacement surgery were enrolled. Patients were divided in two groups based on the cardioplegia solution used. In group 1 (56 patients), long-acting lignocaine based-blood cardioplegia solution was administered as a single dose while in group 2 (54 patients), standard St Thomas IB (short-acting blood-based cardioplegia solution) was administered and repeated every 20 minutes. All the patients were compared for preoperative baseline parameters, intraoperative and all the postoperative parameters. RESULTS: We did not find any statistically significant difference in preoperative baseline parameters. Cardiopulmonary bypass time were 73.8±16.5 and 76.4±16.9 minutes (P=0.43) and cross clamp time were 58.9±10.3 and 66.3±11.2 minutes (P=0.23) in group 1 and group 2, respectively. Mean of maximum inotrope score was 6.3±2.52 and 6.1±2.13 (P=0.65) in group 1 and group 2, respectively. We also did not find any statistically significant difference in creatine-phosphokinase-MB (CPK-MB), Troponin-I levels, lactate level and cardiac functions postoperatively. CONCLUSION: This study proves the safety and efficacy of long-acting lignocaine-based single-dose blood cardioplegia compared to the standard short-acting multi-dose blood cardioplegia in patients requiring the single valve replacement. Further studies need to be undertaken to establish this non-inferiority in situations of complex cardiac procedures especially in compromised patients.

Candidiasis cutánea generalizada en recién nacido a término / Generalized cutaneous candidiasis in newborn at term

Introducción. La candidiasis cutánea es una enfermedad que afecta tanto a población infantil como adulta. Las forma de presentación puede ser localizada o sistémica y el agente etiológico múltiple, siendo las especies infecciosas de Candida albicans más prevalentes en niños. Objetivo. Presentar un caso de candidiasis cutánea congénita cuya causa aparente fue la transmisión vertical durante el parto. Material y metodología. Se describe el caso de un recién nacido a término expuesto a una candidiasis vaginal subclínica, que desarrolló una candidiasis cutánea congénita por C. albicans asociada a sepsis y dificultad respiratoria en las primeras 24 horas de vida. Se practicaron hemocultivos, biopsia cutánea de las lesiones pápulopústulo-vesiculosas, análisis de sangre y punción lumbar. Resultados. En la bioquímica y el hemograma se encontró una proteína C reactiva de 5,7 mg/dl, leucocitosis con desviación a la izquierda y anemia leve. A las 24 horas, en el control se encontró una proteína C reactiva (7,82 mg/dl) que fue en aumento progresivo durante tres días, por lo que se practicó punción lumbar. El hemocultivo fue positivo para Staphylococcus aureus. La biopsia cutánea dio como resultado histológico la candidiasis cutánea. Conclusiones. El diagnóstico precoz es fundamental para prevenir complicaciones derivadas del cuadro producido por C. albicans en neonatos.

Introduction. Cutaneous candidiasis is a disease that affects children as well as adults. The presentation may be localized or systemic, and with multiple etiological agents. The most prevalent infecting species in children differs from that of the adult. Objective. A case is presented where a congenital cutaneous candidiasis was transmitted to the child during birth. Materials and methods. A full term newborn was exposed to a subclinical vaginal candidiasis infection, and 24 hr after birth, developed congenital cutaneous candidiasis. The etiological agent was Candida albicans, and was associated with sepsis and respiratory distress. Blood cultures, cutaneous biopsy of vesicular lesions, blood tests and lumbar puncture were performed. Results. Biochemistry and blood count showed a CRP of 5.7 mg/dl, leukocytosis with left shift and mild anemia. After 24 hr, the blood analyses showed an increase in a CRP (7.8 mg/dl) and increased progressively for three days; consequently, a lumbar puncture was performed. Blood culture was positive for Staphylococcus aureus. Cutaneous biopsy confirmed the cutaneous candidiasis. Conclusions. The early diagnosis is essential to prevent complications derived by the Candida albicans in newborns.

Effect of chloride dialysate concentration on metabolic acidosis in aintenance hemodialysis patients

Hyperchloremia is one of the multiple etiologies of metabolic acidosis in hemodialysis (HD) patients. The aim of the present study was to determine the influence of chloride dialysate on metabolic acidosis control in this population. We enrolled 30 patients in maintenance HD program with a standard base excess (SBE) ≤2 mEq/L and urine output of less than 100 mL/24 h. The patients underwent dialysis three times per week with a chloride dialysate concentration of 111 mEq/L for 4 weeks, and thereafter with a chloride dialysate concentration of 107 mEq/L for the next 4 weeks. Arterial blood was drawn immediately before the second dialysis session of the week at the end of each phase, and the Stewart physicochemical approach was applied. The strong ion gap (SIG) decreased (from 7.5 ± 2.0 to 6.2 ± 1.9 mEq/L, P = 0.006) and the standard base excess (SBE) increased after the use of 107 mEq/L chloride dialysate (from -6.64 ± 1.7 to -4.73 ± 1.9 mEq/L, P < 0.0001). ∆SBE was inversely correlated with ∆SIG during the phases of the study (Pearson r = -0.684, P < 0.0001) and there was no correlation with ∆chloride. When we applied the Stewart model, we demonstrated that the lower concentration of chloride dialysate interfered with the control of metabolic acidosis in HD patients, surprisingly, through the effect on unmeasured anions.

Comparison of corneal endothelial cell loss during phacoemulsification using continuous anterior chamber infusion versus those using ophthalmic viscosurgical device: randomized controlled trial.

AIM: We conducted this study to evaluate and compare corneal endothelial cell loss between phacoemulsification with continuous anterior chamber infusion using anterior chamber maintainer (ACM) and phacoemulsification using ophthalmic viscosurgical device (OVD). MATERIALS AND METHODS: This was a prospective, randomized controlled trial. Fifty eyes of 47 patients of senile cataract undergoing phacoemulsification were included. Patients were randomly allocated into two groups of 25 eyes each. Cataract surgery was performed by phacoemulsification with anterior chamber (AC) continuous infusion with balanced salt solution (BSS) plus and ACM without OVD in Group A, and in Group B, phacoemulsification was performed using OVD with BSS plus. Corneal endothelial cell count and pachymetry were performed preoperatively and postoperatively on day 1, day 7, and day 30. The mean increase in pachymetry was 4.86%, 2.94%, and 1.94%, (Group A) and 5.95%, 3.94%, and 0.51%, (Group B) on first, seventh, and 30 th postoperative day respectively. The difference between the percentage increase in pachymetry between the two groups was not significant at day 1 ( P = 0.441), day 7 ( P = 0.298), and day 30 ( P =0.174) postoperatively. The density of endothelial cells decreased postoperatively (day 30) by 7.38% (Group A) and 7.47% (Group B) without any significant statistical difference ( P = 0.983) between two groups. CONCLUSION: Use of ACM for continuous AC infusion and omission of OVD during phacoemulsification did not cause significant difference in corneal swelling or endothelial cell loss in the immediate postoperative period up to one month.

Isoniazid Toxicity Presenting As Status Epilepticus and Severe Metabolic Acidosis.

Isoniazid (INH) is an integral component of treatment of tuberculosis. An acute overdose is potentially fatal and is characterized by the clinical triad of repetitive seizures unresponsive to the usual anticonvulsants, metabolic acidosis with a high anion gap and coma. The diagnosis of INH overdose should be considered in any patient who presents to emergency medical services (EMS) with the triad. We report a patient presenting with multiple generalised tonic clonic (GTC) convulsions with severe metabolic acidosis as a manifestation of INH toxicity. ©

Padronização de modelo de coração isolado "working heart" com circulação parabiótica / Development of isolated swine "working heart model" with parabiotic circulation

OBJETIVO: Desenvolver modelo de coração isolado de suíno "working heart" sob suporte por circulação parabiótica e verificar se o mesmo é estável e se possibilitou de forma efetiva a mensuração dos dados propostos. MÉTODOS: O modelo foi padronizado durante preparação para estudo de associação de agente à solução cardioplégica. Foram realizados 18 experimentos com um animal suporte e um animal doador em cada. O coração do animal doador foi perfundido como coração isolado pelo animal suporte em modo de execução de trabalho ("coração ejetante"). O coração isolado foi submetido à isquemia regional por pinçamento da artéria interventricular anterior seguido de isquemia global. Durante reperfusão, com o coração ejetante (em modo "working heart"), aos 30, 60 e 90 minutos foram medidos parâmetros hemodinâmicos de contratilidade e metabólicos, obtendo-se assim a elastância máxima (Emáx), o trabalho sistólico pré-recrutável (PRSW), rigidez do ventrículo (EDPRV), fluxo coronariano, consumo de oxigênio e dosagens de lactato e glicose. RESULTADOS: Os animais suporte ficaram estáveis durante todo o experimento. O pH, a pressão parcial de oxigênio e o hematócrito foram mantidos estáveis e dentro da faixa fisiológica. O coração isolado foi perfundido de forma adequada durante todo o experimento. Os dados hemodinâmicos e metabólicos propostos puderam ser mensurados adequadamente e sempre com o coração ejetante, em modo de execução de trabalho ("working heart"). CONCLUSÃO: O modelo de coração isolado desenvolvido tipo "working heart" se manteve estável durante todo o experimento, sem a administração de drogas cardiotônicas e possibilitou a mensuração de todos os dados propostos de forma efetiva com o coração executando trabalho.

OBJECTIVE: To develop an isolated working heart model with parabiotic circulaton in swines and verify its stability and possibility to allow effective measurements of hemodinamic and metabolic data. METHODS: This model was developed during study of association of agents to cardiolegia. There were performed 18 experiments, each with a support animal and a donor animal. Donor animal heart was perfused as isolated working heart with parabiotic circulation from support animal. Isolated heart underwent regional ischemia by interventricular artery clamping, followed by global ischemia. During reperfusion in working heart state mode at 30, 60 and 90 minutes, contractility indices such as elastance, preload recruitable stroke work index and metabolic data were acquired. RESULTS: Support animals were kept stable throughout the procedures without use of blood transfusions or vasoactive drugs. pH, oxygen partial pressure and hematocrit were kept stable and within physiologic ranges. Isolated heart was perfused adequately throughout the experiment. All hemodinamic and metabolic data proposed were adequately measured in working heart state mode. CONCLUSION: This swine isolated "working heart" model was kept stable throughout the experiments with no administration of vasoactive drugs and it allowed adequate measurements of metabolic and hemodinamic data.

Bicarbonate kinetics in Indian males.

Measurement of rates of in vivo substrate oxidation such as that of glucose, fatty acids and amino acids, are based on tracer (14C or 13C) data, and often depend on the isotopic content of expired CO2. The recovery of tracer-labelled CO 2 generated from the oxidation of 13C labelled substrates may not be 100% over short term. This can lead to underestimation of oxidation rate of substrates, and consequently a correction for the incomplete recovery of tracer has to be applied by the determination of the recovery of 13CO2 in the breath during tracer bicarbonate infusions. We have studied the recovery of tracer-labelled bicarbonate using a bolus administration model, and further characterized kinetics of bicarbonate using a three-compartment model, to assess which compartmental fluxes changed during the change from a fasted state to fed state. Recovery of bicarbonate was lower at 69% and 67% (fasted and fed state) than the value of 71% and 74% found during earlier longer term of continuous infusions. During feeding, there was a 20-fold increase in the flux of bicarbonate between the central compartment and the compartment that was equivalent to the viscera. This study shows that the difference between the fasted and fed state recovery of tracer bicarbonate similar to that obtained with continuous infusions, and that bicarbonate fluxes show large changes between different compartments in the body depending on metabolic state.

Correlation between intradialytic hypotension in patients undergoing routine hemodialysis and use of acetate compared in bicarbonate dialysate.

AIM: To determine the incidence of intradialytic hypertension (IDH) during hemodialysis (HD) in end-stage renal disease (ESRD) patients using acetate dialysate compared to those using bicarbonate dialysate. METHODS: This study was a double-blind cross-over randomized clinical trial. The effect of acetate and bicarbonate dialysate on blood pressure was analyzed in two consecutive HD sessions. The selected subjects were 41 stable ESRD patients scheduled for dialysis 2 times/week/from the HD unit of Dr.Soetom Hospital Surabaya, aged between 21-65 years old, with a hemoglobin level > or = 7 g/dL, serum albumin > or = 3 mg/dL and interdialytic weight gain < 4 Kg, and an average Qb 150-250 ml/minute. The dialysate sodium level was 138 mEq/L/ The study subjects were divided into tow groups: 21 patients in the group who received Acetate on the first session and Bicarbonate on the next (AB) and 20 patients in the group receiving Bicarbonate first (BA). Comparison of IDH during use of each dialysate was analyzed by Chi-Square and Mc Nemar Chi-Square test. RESULTS: No characteristic differences were found in both groups: HD duration (for AB) was 28.83 +/- 13.89 vs. 34.95 +/- 24.80 months (for BA) (p = 0.333); Age (for AB) was 47.61 +/- 9.49 vs. 47.75 +/- 11.80 years (for BA) (p = 0.969); Hemoglobin (Hb) level (for AB) 8.19 +/- 0.84 vs. 7.94 +/- 0.41 mg/dL (for BA) (p = 0.238); serum Albumin (for AB) was 3.79 +/- 0.26 vs. 3.82 +/- 0.30 g/dl (for BA) (p = 0.652). The number of patients with IDH during acetate dialysate with IDH during bicarbonate dialysate was 1 (2.4%). Overall, there were 11 patients with Diabetic Kidney Disease (26.8%). Six out of them (54.5%) had IDH during acetate dialysate and only and 1 patient (9.1%) had IDH during acetate and bicarbonate. CONCLUSION: The incidence of IDH in hemodialysis using acetate is significantly greater than that when bicarbonate is used (p = 0.000).

Intraocular irrigating solutions. A clinical study of BSS Plus and dextrose bicarbonate fortified BSS as an infusate during pars plana vitrectomy.

PURPOSE: To compare the effect of Balanced Salt Solution Plus (BSS Plus, Alcon Laboratories, Fort Worth, Texas, USA) and fortified regular BSS on the cornea and lens, when used for continuous irrigation in pars plana vitrectomy (PPV) surgery. METHODS: Prospective, investigator masked, randomised study. Forty patients were randomly assigned to undergo PPV using BSS Plus (n=20) or fortified BSS (n=20) [regular BSS, fortified with 10.5 cc. of dextrose in water (D5W) and 13.1 cc. of 8.4% sodium bicarbonate]. Intraoperative features of the corneal epithelium, postoperative changes in the corneal endothelial cell denstiy (ECD) at 3 months, and clarity of the lens during surgery and postoperatively were evaluated. RESULTS: Intraoperative epithelial changes were similar in both groups with 7 (35%) of the cases having the epithelium removed in the BSS Plus group and 8 (40%) in the BSS fortified group (P=0.23). The mean differences in ECD (3 months versus preoperative) in the operated eyes when adjusted for changes in the control eye showed no difference with the type of BSS (P=0.98). Intraoperative lens changes were more significant (P=0.018) in the BSS fortified group. Postoperative lens status at 3 months was similar for both groups. Though there was a trend towards worse postoperative nuclear sclerosis change in the BSS fortified group, it was not significant (P=0.160). CONCLUSION: Standard BSS fortified with dextrose and bicarbonate is an efficacious infusion fluid during pars plana vitrectomy. Both solutions showed comparable effects on postoperative corneal endothelial cell density and corneal epithelial changes intraoperatively. BSS fortified has more lenticular changes intraoperatively than BSS Plus although no lens had to be removed in either group. The study implications are important since BSS fortified is significantly less expensive than BSS Plus.

Efecto del bicarbonato de sodio sobre la actividad colinesterasa en cerebro, eritrocitos, plasma e higado de ratas intoxicadas con paratión

El presente trabajo se realizó con la finalidad de evaluar el efecto que tiene el bicarbonato sobre la actividad de la acetil colinesterasa de diversos tejidos, en animales de experimentación intoxicados con paratión. Para ello se formaron cuatro grupos de diez ratas cada uno. El grupo A sirvió de control . Los grupos B y C recibieronm por vía intraperitoneal paratión y además este último recibió bicarbonato de sodio luego de quine minutos de ser administrado el organofosforado. El grupo D recibió únicamente bicarbonato de sodio. Se dosaron las actividades colinesterásicas de los cuatro grupos en plasma , eritrocito, cerebro e hígado, por el método de Ellman modificado, y se compararon las actividades en los diferentes tejidos entre los grup[os de estudio con el fin de ver como variaba la actividad de la enzima inhibida por el paratión, por efecto del bicarbonato. Se encontró que la inhibición de la actividad colinesterásica, por el efecto del paratión, era significativa a nivel plasmático, cerebral y hepático, mas no a nivel eritrocítico; además se vió que el bicarbonato por si solo inhibia la actividad de la enzima en los mismos tejidos, de manera significativa. Por otro lado se encontró que la actividad colinesterásica inhibida por el órgano fosforado, se recuperó luego de la administración del bicarbonato de sodio. Con los resultados obtenidos se propone que la acción del bicarbonato sería desactivando al insecticida mismo y no sobre la colinesterasa.

Efecto de la alcalinización y el calentamiento de las soluciones anestésicas sobre el periodo de latencia en el bloqueo de plexo axilar vía axilar / Effects of anesthetic Warming and alcalinization upon the latency period in axilary blockade through axilary approach

Se estudiaron tres grupos de 10 pacientes cada uno, de ambos sexos, edad promedio de 34.8 ñ 8.8 años, peso promedio de 68.8 ñ 2.3 zkg. talla promedio de 156 ñ cm. y estados físicos 1 y 2, programados para cirugía electiva ortopédica o reconstructiva del miembro toráxico. A todos ellos se les administró lidocaína al 2 por ciento con epinefrina para bloqueo de plexo braquial vía axilar a dosis de 7 mg/kg. al grupo I sin modificaciones , al grupo II se adicionó bicarbonato de sodio y al grupo III se aumentó la temperatura a 37ºC, para reducir el tiempo de latencia. El tiempo promedio de latencia observado para el grupo I fue de 15.2 ñ 7.3 minutos y para el grupo II fue de 9.1 ñ 1.9 minutos, existiendo diferencias significativas estadísticamente p<0.01. El tiempo promedio de latencia para el grupo III fue de 2.4 ñ 1.3 minutos y en comparación con los dos grupos previos se aprecia una diferencia significativa estadísticamente (P<0.005). En suma, tanto la alcalinización como el calentamiento de las soluciones anestésicas con eficaces para disminuir el tiempo de la latencia

Hemodiálisis con sodio elevado / Hemodialysis with increased sodium

Durante la hemodiálisis, las complicaciones relacionadas con los cambios hemodinámicos y de la osmolaridad dificultan con frecuencia el proceder dialítico. Para disminuir estas complicaciones se han desarrollado una serie de procedimientos técnicos como son: el empleo de bicarbonato y el aumento de la concentración de sodio en el dializado. Con el fin de explorar este último proceder se estudiaron 30 hemodiálisis, 15 de ellas con sodio estándar (135 mmol/L) y 15 con sodio elevado (150 mmol/L durante la primera mitad de la diálisis: en ambos grupos se valoraron las complicaciones intradialíticas, así como el aumento de peso en el período interdialítico posterior. La hipotensión arterial ocurrió en el 20 por ciento de las hemodiálisis con sodio normal y en ninguna de las de sodio elevada. El aumento de peso promedio en los períodos interdialíticos fue de 1,486 kg +- 0,946 y de 2,526 kg -+ 1,122 para la hemodiálisis con sodio normal y elevado respectivamente. Se considera que el proceder es útil en pacientes hemodinámicamente inestables, siempre que se controle la ganancia de peso, interdialítica.

Estudo da rugosidade superficial da resina composta, submetida à açäo do jato de bicarbonato de sódio: efeito de material e tempo de aplicaçäo / Study of superficial rugosity of the composite resins submitted to the action of sodium bicarbonate: material effect and application time

Foi realizado estudo comparativo da rugosidade superficial de cinco marcas diferentes de resinas compostas: Adaptic, Herculite, Estic-Microfill, Silux e P-30, submetidas à açäo do jato de bicabornato de sódio do aparelho Profident, nos tempos de aplicaçäo de 30 a 60 segundos. Os corpo-de-prova foram confeccionados com auxílio de uma matriz circular, e as alteraçöes superficiais foram analisadas no aparelho Hommel Tester T.1000 para medir a rugosidade inicial e após o tratamento com o jato abrasivo. Os dados obtidos foram submetidos a tratamento estatístico que após análise e discussäo, permitiram concluir que a aplicaçäo do jato de bicarbonato de sódio altera a superfície das resinas compostas, torando-a mais rugosa, e que os materiais estudados exerceram níveis diferentes de rugosidade. O Herculite apresentou a superfície menos rugosa e o Adaptic a mais rugosa ficando os materiais P-30, Silux e Estic-Microfill numa posiçäo intermediária

Short term study on relative merits of acetate and bicarbonate dialysis.

We did a double blind, crossover, prospective study comparing bicarbonate and acetate containing solutions in haemodialysis. Thirty stable patients with end stage renal disease on maintenance haemodialysis while awaiting a renal transplant were each studied on three dialysis with acetate and three with bicarbonate. Nine patients developed symptoms like headache, nausea, vomiting, giddiness, and malaise and developed hypotension during acetate dialysis and three patients during bicarbonate dialysis. There were symptoms during 16.66% of acetate dialysis sessions and 5.55% of bicarbonate dialysis sessions. (P less than 0.05). There was a statistically significant decrease in PaO2 and PaCO2 on acetate dialysis at 30 minutes after initiation of dialysis. There was no significant difference in weight loss on dialysis, or in blood pressure and correction of acidosis. We conclude that bicarbonate dialysis is better tolerated, but acetate intolerance is not a major problem since we use small surface area dialysers (0.8 M2).

Efeito da ingestäo de substâncias alcalinas pré-esforço sobre os níveis de lactato plasmático / Effect of the pre-exertion ingestion of alkaline substances on the plasmatic lactate levels

O presente trabalho teve como objetivo verificar as alteraçöes dos teores de lactato plasmático com a ingestäo de água bicarbonada em ciclistas submetidos a cargas crescentes de trabalho. Foram utilizados 4 (quatro ciclistas treinados, do sexo masculino, aos quais foi administrado água bicarbonatada (1% e 2% de bicarbonato de sódio) e placebo duas horas antes da atividade. Os quatro atletas passaram pelo mesmo protocolo, ou seja, todos receberam as três substâncias em dias diferentes de trabalho com distribuiçäo aleatória. As cargas de trabalho foram de 100W, 200W, 250W e 300W por 3 (três) minutos cada. A mostra de sangue foi colhida ao final de cada carga bem como em repouso e uma hora após a ingestäo das substâncias em repouso. Os resultados obtidos demonstraram que a açäo da substância bicarbonatada é mais efetiva na concentraçäo de 2% com a carga de 200W. Na carga de 250W os valores de lactato encontrados demonstraram uma semelhança entre as duas concentraçöes de bicarbonato, quando comparados ao placebo demonstraram ser efetivas na reduçäo do lactato plasmático

Un método práctico para la administración de bicarbonato de sodio / A practical method for the administration of sodium bicarbonate

Se presentó un método práctico para emplear bicarbonato de sodio utilizado durante más de 10 años por muchos cirujanos en la Sala de Cuidados Intermedios de Cirugía, que igualaba el número de ámpulas de bicarbonato de sodio al 4 % requerido por los pacientes con el valor negativo del exceso de bases. Porque esta regla práctica no se cumple en los pesos corporales extremos y por haber encontrado una regularidad matemática entre los valores "ideales" del peso corporal y el EB-, se diseña un nomograma útil para calcular la dosis del medicamento en enfermos con pesos corporales entre 50 y 90 kg, con valores de EB- entre 5 y 20 MEq/l

Protective Effect of Urinary Alkalinization on Gentamicin Nephrotoxicity in Rats

We investigated the effect of urinary alkalinization accomplished by intraperitoneal injection of sodium bicarbonate and acetazolamide on gentamicin nephrotoxicity in male Fisher 344rats. Forty rats (body weight 200-300g) were divided into four groups: control (gentamicin 20mg/kg, bid), high sodium load (gentamicin 20mg/kg, 25cc of saline, bid), low bicarbonate (gentamicin 20mg/kg, 25cc of sodium bicarbonate 100mEq/L, 2.5mg of Diamox, bid) and high bicarbonate (gentamicin 20mg/kg, 10cc of sodium bicarbonate 250mEq/L, 2.5mg of Diamox, bid) groups. All drugs and electrolyte solutions as mentioned above were administered intraperitoneally twice a day for seven days and changes in renal functions were studied. While salt loading failed to influence the severity of gentamicin nephrotoxicity, urinary alkalinization induced by bicarbonate and acetazolamide injection showed remarkable ameliorating effects on gentamicin nephrotoxicity. The high bicarbonate group exhibited more beneficial effects than the low bicarbonate group on gentamicin nephrotoxicity. So, urinary alkalinization seems to be an effective method for the prevention of gentamicin nephrotoxicity in rats.