S. Gordon

Prediction of creatinine clearance from serum creatinine in spinal cord injury patients.

Measured endogenous creatinine clearance (Ccr) was compared with the predicted Ccr in 22 paraplegic, 36 tetraplegie and n ambulatory male individuals as well as 11 ambulatory females all of whom had normal renal function. While the predicted and measured values closely matched in the ambulatory patients the predicted values in the spinal cord injured patients consistently exceeded the measured values. It thus appears that the original Cockcroft and Gault formula;when applied to SCI patients can be misleading. Modification of the original formula using a correction factor of 0.8 in paraplegics and 0.6 in tetraplegics was found to allow prediction of Ccr from age, sex, body weight, and serum creatinine in these patients with reasonable accuracy.

Renal pathology in end-stage renal disease associated with Paraplegia

In the present study we report the renal pathological findings from autopsy material along with relevant clinical data on 21 spinal cord injury patients with end-stage renal disease (SCI-ESRD) treated with maintenance haemodialysis. These data are compared with the relevant clinical and post-mortem findings on 43 ambulatory dialysis patients who expired during the same time period.The SCI-ESRD patients exhibited markedly different clinical and renal histo-pathological data when compared to the ambulatory—ESRD group. Chronic pyelonephritis and amyloidosis dominated the findings and were the major causes of renal insufficiency. Acute pyelonephritis, papillary necrosis, calculous disease, pyonephrosis and perinephric abscess formation were also more frequently present in the SCI-ESRD patients. Hypertension and nephrosclerosis, which were common findings in the ambulatory—ESRD patients were comparatively rare in the SCI-ESRD patients. In addition, the incidence of acquired cystic disease (ACD) was considerably less in the SCI-ESRD group. Although the reasons for these findings are not entirely clear several possible explanations are given.Infection with gram negative sepsis was the predominant cause of death in the SCI-ESRD patients, while death secondary to cardiovascular disease predominated in the ambulatory-ESRD group. Furthermore, the urinary tract and infected decubitus ulcers were determined to be the major source for sepsis in the SCI patients. From these findings it would follow that more effective prevention and control of these infections would result in not only a lower incidence of renal failure but also a substantially reduced morbidity and mortality in chronic SCI.

Amikacin Pharmacokinetics in Patients with Spinal Cord Injury

The influence of chronic (> 1 yr duration) spinal cord injury (SCI) on the disposition of amikacin was studied in seven healthy subjects with SCI (five paraplegic, two tetraplegic) and seven able‐bodied controls (intact neuraxes). The time course of amikacin serum concentration after a 30‐minute infusion (7.5 mg/kg) was followed for up to 8.5 hours using fluorescence polarization immunoassay. Pharmacokinetic values were estimated by a noncompartmental analysis (NC). Amikacin steady‐state volume of distribution (Vss) was increased to 0.20 ± 0.04 l/kg (mean ± SD) as compared to 0.17 ± 0.02 l/kg in able‐bodied controls (p 0.03), and its mean terminal elimination half‐life in patients with SCI was prolonged by 0.64 hours over the control value of 2.11 ± 0.27 hours (p 0.01). The NC estimated mean residence time (MRT) in patients with SCI (3.65 ± 0.75 hrs) was 0.89 hours longer than that observed in controls (p 0.03). Our data suggest that the Vss, half‐life, and MRT of amikacin are increased in persons with chronic SCI. As a result, amikacin dosing regimens developed in able‐bodied humans may demonstrate diminished efficacy when extrapolated uncritically to these patients.

Erythropoiesis Associated with Viral Hepatitis in End Stage Renal Disease

We describe an end stage renal disease (ESRD) patient on maintenance hemodialysis who developed a spontaneous increase in erythropoiesis associated with an episode of viral hepatitis. Resolution of the hepatitis was accompanied by a reduction in erythropoiesis with the hemoglobin and hematocrit falling back toward the patients low baseline levels. Plasma erythropoietin (Ep) titers were measured during the period of active erythropoiesis and were found to be low to low normal. The unusual phenomenon of increased erythropoiesis in ESRD following liver injury has been previously described and is thought to be mediated through increased hepatitic Ep production. The low Ep titers measured in our patient, however, suggest that the liver may be capable of stimulating erythropoiesis by another mechanism.

Lipid abnormalities in chronic renal failure associated with spinal cord injury.

Serum lipid fractions were studied in ten patients with chronic renal failure (CRF) associated with long-standing spinal cord injury (SCI). A group of age-and-sex-matched patients with long-standing SCI but normal renal function were included for comparison. Serum triglycerides were markedly elevated in SCI-CRF patients. Both SCI groups exhibited moderate hypocholesterolemia. High density lipoprotein (HDL) cholesterol was severely reduced in the SCI-CRF group and moderately reduced in the SCI-control group. Chronic renal failure, reduced physical activity and several other factors may be operative in the genesis of hypertriglyceridemia and reduced HDL-cholesterol levels in this condition. Further investigations are necessary to examine the possible effect of these lipid abnormalities on the cardiovascular system in these patients.

Features of Residual Renal Function in End-Stage Renal Failure Associated with Spinal Cord Injury

The characteristics of end-stage renal disease (ESRD) complicating spinal cord injury (SCI) were studied retrospectively in 43 male hemodialysis patients. A control group of male patients dialyzed in the same institution were studied for comparison. The SCI patients had significantly lower serum creatinine concentrations and daily urinary creatinine excretion than the control group, despite comparable creatinine clearances. Therefore, serum creatinine, when compared with the familiar values in non-SCI patients, may greatly underestimate the severity of the renal impairment. Urine optput was higher, urine specific gravity lower, and renal glucosuria more common in the SCI patients. 24-hour urinary protein excretion was higher and serum albumin was lower in the SCI patients, with 48% of the patients exhibiting nephrotic range proteinuria. Urine pH was markedly elevated, and pyuria and bacteruria were present in all SCI patients. Fractional excretion of potassium (159 ± 16%) exceeded its filtered load in most SCI patients.

Clinicopathological Characteristics of Dialysis Patients with Spinal Cord Injury

Forty-three spinal cord injured patients with endstage renal disease (ESRD) maintained on hemodialysis were studied. The most prevalent renal lesions consisted of chronic pyelonephritis and amyloidosis while the main renal functional features included nephrotic range proteinuria, high urine output and relatively low serum creatinine for the degree of renal insufficiency. Normocytic, normochromic anemia with low reticulocyte response, low serum iron and iron binding capacity and high transfusion requirement and serum ferritin were noted. Various cardiovascular, pulmonary and gastrointestinal abnormalities were found with considerable frequencies. The incidence of amyloidosis was much higher than that reported previously. This is thought to be due to continued progression of amyloidosis occasioned by longer survival in the present series.

Extrinsic and Common Coagulation Pathways in End-stage Renal Disease Associated with Spinal Cord Injury

Data on the effects of combined long-standing spinal cord injury (SCI) and end-stage renal disease (ESRD) on blood coagulation system are limited. We studied the extrinsic and common pathways of blood coagulation system in 9 men with SCI-ESRD treated with maintenance hemodialysis. Plasma procoagulant activities of factors (F)VII, X and II were measured in a clotting assay using appropriate deficient plasmas as substrate. In addition, the antigen concentration of FII was measured using monospecific antibodies against human FII raised in goat in a gradient plate immunodiffusion system. Also measured were plasma fibrinogen concentration and platelet count. The results were compared with those obtained in a group of 10 ambulatory ESRD patients and 8 normal control volunteers. Plasma coagulant activity of FVII was markedly elevated and plasma fibrinogen concentration was moderately increased in SCI-ESRD patients: In contrast, plasma FII was mildly depressed while platelet count was within normal limits in SCI-ESRD patients. The data indicate that the combination of SCI and ESRD can lead to the alteration of the extrinsic and common coagulation pathways. Further studies are needed to elucidate the precise mechanism and the clinical significance of the observed abnormalities.

Nutritional evaluation of hemodialysis patients with and without spinal cord injury.

Both end stage renal disease (ESRD) and spinal cord injury (SCI) represent major disabling conditions that may be associated with protein-calorie malnutrition (PCM). The prevalence of PCM in ESRD, however, remains unknown, and virtually no data exist regarding the status of PCM in patients with both SCI and ESRD. In this study we evaluated 23 ambulatory-ESRD patients and 11 SCI-ESRD patients utilizing a range of parameters recommended for assessing nutritional status in ESRD. Based on these parameters, our results show evidence for PCM in a substantial proportion of both groups. When the two groups were compared, however, the frequency and severity of PCM were significantly greater in the SCI-ESRD patients. Important factors felt to adversely influence nutritional status in the SCI-ESRD patients were intercurrent infection and amyloidosis that were found to frequently complicate this setting. It is also probable that the combined effects of PCM and ESRD significantly predispose these patients to further infection, establishing a vicious cycle.

Frequency and Spectrum of Pulmonary Diseases in Patients with Chronic Renal Failure Associated with Spinal Cord Injury

We reviewed autopsy records from 20 patients with long-standing spinal cord injury and chronic renal failure. Only 1 patient had normal pulmonary findings at autopsy. Acute and chronic pulmonary diseases were found in 16/20 and 17/20 patients, respectively. Pneumonia and fluid overload were the most common acute diseases. Interstitial and pleural fibrosis were the most common chronic diseases. However, a variety of illnesses including pulmonary amyloidosis, calcification, and arteriosclerosis were also found. Arterial blood gas studies indicated a high prevalence of hypoxemia. We concluded that significant pulmonary abnormalities are present in almost all spinal cord injury-chronic renal failure patients.