Rectal ulcer due to Kayexalate deposition - an unusual case

SUMMARY Sodium polystyrene sulfonate (PSP) or Kayexalate is a cation-exchange resin, widely used in the management of hyperkalaemia due to renal disease. A rare, yet potentially dangerous, adverse event related to sodium polystyrene sulfonate use is intestinal mucosal injury, especially in the colon. The injury to the gastrointestinal mucosa can range from mild and superficial to wall necrosis and bowel perforation. The mechanism that leads to mucosal damage remains unclear. However, it is believed that sorbitol, commonly given to counteract PSP's tendency to cause constipation, may play an important role in the development of gastrointestinal injury. Other potential risk factors are uraemia or end-stage renal disease, hemodynamic instability, solid organ transplantation, postoperative status and concomitant opioid administration. The authors present a case of diarrhoea and haematochezia after the administration of PSP without sorbitol, in a patient with hyperkalaemia due to acute kidney injury, in the absence of other risk factors. A colonoscopy was performed and revealed a rectal ulcer which histological findings were suggestive of mucosal injury due to Kayexalate deposition. This case supports the concept that this widely used drug can itself, without sorbitol, cause injury to the gastrointestinal wall. Even though this is a rare adverse effect, the widespread use of this medication may put a large population at risk.

RESUMO O polistireno sulfonato de sódio (PSP) ou kayexalato é uma resina de troca iônica, amplamente usada no tratamento da hipercalemia associada à doença renal. Um efeito adverso raro, mas potencialmente grave, dessa terapêutica é a agressão à parede do trato gastrointestinal, principalmente ao nível do cólon, que pode ser ligeira e superficial ou culminar em necrose e perfuração intestinal. O mecanismo pelo qual o PSP lesa a mucosa intestinal não é totalmente conhecido. Contudo, pensa-se que o sorbitol, frequentemente administrado em simultâneo para contrabalançar o efeito obstipante do PSP, possa ter um papel preponderante no desenvolvimento de lesão gastrointestinal. Outros potenciais fatores de risco são a presença de uremia ou doença renal em estágio terminal, instabilidade hemodinâmica, pós-operatório, pós-transplante renal e a administração concomitante de opioides. Os autores descrevem um caso de diarreia e hematoquesias após a administração de PSP sem sorbitol, numa paciente com hipercalemia secundária a lesão renal aguda, sem outros fatores de risco para o desenvolvimento desse efeito adverso. A investigação etiológica com colonoscopia revelou a presença de uma úlcera retal, cujo estudo histológico foi compatível com lesão por deposição de cristais de kayexalato. Este relato incomum reforça o conceito de que este fármaco de uso frequente, mesmo na ausência de sorbitol, pode ser lesivo para a mucosa intestinal. Assim, e apesar de este ser um efeito adverso raro, a utilização difundida do PSP coloca uma vasta população em risco.

Pharmacokinetics and Pharmacodynamics of Luseogliflozin, a Selective SGLT2 Inhibitor, in Japanese Patients With Type 2 Diabetes With Mild to Severe Renal Impairment.

This open-label, parallel-group, multicenter study aimed to assess the effects of renal impairment on the pharmacokinetics, pharmacodynamics, and safety of luseogliflozin. A single 5-mg dose of luseogliflozin was administered to Japanese patients with type 2 diabetes mellitus in the following groups: G1, normal renal function; G2, mild renal impairment; G3a, mild to moderate impairment; G3b, moderate to severe impairment; G4, severe impairment, based on estimated glomerular filtration rate (eGFR; ≥90, 60-89, 45-59, 30-44, 15-29 mL/min/1.73 m2 , respectively). While luseogliflozin pharmacokinetics were similar for patients across all renal function groups, the increase in plasma concentration was slightly slower and maximum concentration was slightly reduced in the lower eGFR groups compared with the other groups. However, luseogliflozin pharmacodynamics were affected by the severity of renal impairment. Urinary glucose excretion (UGE) increased in all groups relative to baseline levels, but the degree of UGE increase was smaller in the lower eGFR groups. Moreover, plasma glucose AUC changes from baseline tended to be smaller in the lower eGFR groups. No clear trends were observed between eGFR and incidence, type, or severity of adverse events. Thus, luseogliflozin administration should be carefully considered, as patients with renal impairment may show an insufficient response to treatment.

Rectal ulcer due to Kayexalate deposition - an unusual case.

Sodium polystyrene sulfonate (PSP) or Kayexalate is a cation-exchange resin, widely used in the management of hyperkalaemia due to renal disease. A rare, yet potentially dangerous, adverse event related to sodium polystyrene sulfonate use is intestinal mucosal injury, especially in the colon. The injury to the gastrointestinal mucosa can range from mild and superficial to wall necrosis and bowel perforation. The mechanism that leads to mucosal damage remains unclear. However, it is believed that sorbitol, commonly given to counteract PSP's tendency to cause constipation, may play an important role in the development of gastrointestinal injury. Other potential risk factors are uraemia or end-stage renal disease, hemodynamic instability, solid organ transplantation, postoperative status and concomitant opioid administration. The authors present a case of diarrhoea and haematochezia after the administration of PSP without sorbitol, in a patient with hyperkalaemia due to acute kidney injury, in the absence of other risk factors. A colonoscopy was performed and revealed a rectal ulcer which histological findings were suggestive of mucosal injury due to Kayexalate deposition. This case supports the concept that this widely used drug can itself, without sorbitol, cause injury to the gastrointestinal wall. Even though this is a rare adverse effect, the widespread use of this medication may put a large population at risk.

Vancomycin-resistant Enterococcus faecium bacteraemia as a complication of Kayexalate (sodium polystyrene sulfonate, SPS) in sorbitol-induced ischaemic colitis.

We present the case report of an 80-year-old woman with chronic kidney disease stage G5 admitted to the hospital with fluid overload and hyperkalaemia. Sodium polystyrene sulfonate (SPS, Kayexalate) in sorbitol suspension was given orally to treat her hyperkalaemia, which precipitated an episode of SPS in sorbitol-induced ischaemic colitis with the subsequent complication of vancomycin-resistant Enterococcus (VRE) bacteraemia. SPS (Kayexalate) in sorbitol suspension has been implicated in the development of intestinal necrosis. Sorbitol, which is added as a cathartic agent to decrease the chance of faecal impaction, may be primarily responsible through several proposed mechanisms. The gold standard of diagnosis is the presence of SPS crystals in the colon biopsy. On a MEDLINE search, no previous reports of a VRE bacteraemia as a complication of biopsy-confirmed SPS in sorbitol ischaemic colitis were found. To the best of our knowledge, ours would be the first such case ever reported.

Fermentable Carbohydrates [FODMAPs] Exacerbate Functional Gastrointestinal Symptoms in Patients With Inflammatory Bowel Disease: A Randomised, Double-blind, Placebo-controlled, Cross-over, Re-challenge Trial.

BACKGROUND AND AIMS: Preliminary evidence suggests that fermentable carbohydrate restriction might ameliorate functional gastrointestinal symptoms [FGS] in inflammatory bowel disease [IBD]. Our aim was to determine whether fermentable carbohydrates exacerbate FGS in IBD using a randomised, double-blinded, placebo-controlled, re-challenge trial. METHODS: Patients with quiescent IBD and FGS responsive to a low FODMAP diet were allocated to a series of 3-day [d] fermentable carbohydrate challenges in random order [fructan, 12 g/d; galacto-oligosaccharides [GOS] 6 g/d; sorbitol, 6 g/d; and glucose placebo, 12 g/d], each separated by a washout period. Symptoms and stool output were measured daily during the challenges. RESULTS: Thirty-two patients with IBD, fulfilling criteria for irritable bowel syndrome, functional bloating, or functional diarrhoea, were recruited and data were available for 29 patients completing all arms [12 Crohn's disease, 17 ulcerative colitis]. Significantly fewer patients reported adequate relief of FGS on the final day day of the fructan challenge [18/29, 62.1%] compared with glucose [26/29, 89.7%] [p = 0.033]. There was greater severity of pain [1.1 vs 0.5, p = 0.004], bloating [1.3 vs 0.6, p = 0.002], flatulence [1.5 vs 0.7, p = 0.004], and faecal urgency [0.9 vs 0.4, p = 0.014] on the final day of fructan challenge compared with glucose. CONCLUSIONS: At the relatively high doses used, fructans, but not GOS or sorbitol, exacerbated FGS in quiescent IBD. Further research is required to determine whether a low FODMAP diet reduces FGS in IBD and the degree of FODMAP restriction required for symptom improvement.

Efeitos de osmólitos na L- asparaginase II de Erwinia chrysanthemi em meio aquoso / Effects of omolytes in L- asparaginase II from Erwinia chrysanthemi in aqueous medium

A L- asparaginase é uma enzima aplicada no tratamento de Leucemia Linfoide Aguda, que atua na hidrólise da L- asparagina, privando a célula tumoral de um aminoácido essencial para o seu crescimento. A L- asparaginase, como outros biofármacos, deve ser estável, manter sua atividade específica e formar poucos agregados. A fim de manter a integridade do biofármaco, são utilizados adjuvantes nas formulações farmacêuticas, e dentre os mais importantes estão os osmólitos. Essas moléculas protegem a estrutura nativa da proteína, sendo capazes de interferir na formação de agregados e garantir a estabilidade proteica. O presente trabalho teve o objetivo de estudar o efeito dos osmólitos sacarose, sorbitol, arginina e glicina na atividade específica, estabilidade, cinética e caracterização de agregados na solução de L- asparaginase II de Erwinia chrysanthemi. Os resultados mostraram que a maioria dos osmólitos testados aumentou a atividade específica e a estabilidade da enzima, o que pode estar relacionado com o aumento da velocidade máxima e do kcat observados no ensaio cinético realizado com sacarose e sorbitol. Um perfil diferente de agregados foi encontrado para cada tipo de osmólito. A presença de sacarose ou sorbitol resultou na menor quantidade de agregados na faixa de, respectivamente, 100 a 200 e 200 a 300 nm em relação a enzima sem osmólito. Por outro lado, aumento no número total de agregados e presença de moléculas de alto peso molecular (300 a 500 nm) foram observados nas soluções enzimáticas contendo, respectivamente, glicina e arginina. Dessa forma, os resultados obtidos neste trabalho poderão auxiliar na produção e escolha da formulação de biofármacos, e, consequentemente, melhorar o tratamento medicamentoso de pacientes.

L L-Asparaginase is an enzyme applied in the treatment of Acute Lymphoblastic Leukemia, which acts on the hydrolysis of L- asparagine, depriving the tumor cell of an essential amino acid for its growth. L-asparaginase, as other biopharmaceuticals, must be stable, maintain its specific activity and form few aggregates. In order to maintain the integrity of the biopharmaceutical, adjuvants are used in the pharmaceutical formulations, and among the most importants adjuvants are the osmolytes. These molecules protect the native structure of the protein, being able of interfering in the formation of aggregates and guarantee protein stability. The present work had the objective of studying the effect of the osmolytes sucrose, sorbitol, arginine and glycine in the specific activity, stability, kinetic and aggregates characterization, in L- asparaginase II solution of Erwinia chrysanthemi. The results showed that the majority of the tested osmolytes increased the specific activity of the enzyme and its stability, which may be related to the augment of maximum velocity and kcat observed in the kinetic assay performed with sucrose and sorbitol. A different profile of aggregates was found for each type of osmolyte. The presence of sucrose or sorbitol resulted in the least amount of aggregates in the range of, respectively, 100-200 and 200-300nm in relation to the enzyme without osmolyte. On the other hand, increase in the total number of aggregates and the presence of high molecular weight molecules (300 to 500 nm) were observed in the enzymatic solutions containing, respectively, glycine and arginine. Thus, the results obtained in this work may help in the production and choice of the formulation of biopharmaceuticals and, consequently, improve the drug treatment of patients.

Exposure to sorbitol during lactation causes metabolic alterations and genotoxic effects in rat offspring.

Sorbitol is a polyol used by the food industry as a sweetener. Women are consuming diet and light products containing sorbitol during pregnancy and in the postnatal period to prevent themselves from excessive weight gain and maintain a slim body. Although there is no evidence for the genotoxicity of sorbitol in the perinatal period, this study focused on evaluating the effects of the maternal intake of sorbitol on the biochemical and toxicological parameters of lactating Wistar rat offspring after 14days of mother-to-offspring exposure. A dose-dependent reduction of offspring length was observed. An increase in sorbitol levels determined in the milk was also observed. However, we detected an inverse relationship between the exposition dose in milk fructose and triacylglycerols concentrations. There was an increase in the plasmatic levels of ALT, AST and LDLc and a decrease in proteins, cholesterol and glucose levels in the offspring. Sorbitol exposure caused hepatocyte genotoxicity, including micronuclei induction. Maternal sorbitol intake induced myelotoxicity and myelosuppression in their offspring. The Comet assay of the blood cells detected a dose-dependent genotoxic response within the sorbitol-exposed offspring. According to our results, sorbitol is able to induce important metabolic alterations and genotoxic responses in the exposed offspring.

Ileum and colon perforation following peritoneal dialysis-related peritonitis and high-dose calcium polystyrene sulfonate.

A rare but severe complication, intestinal necrosis, has been reported after sodium polystyrene sulfonate (SPS; Kayexalate) and sorbitol intake. Some case reports described bowel perforation following calcium polystyrene sulfonate (CPS; Kalimate) administration. We report a case of ileum and colon perforation following peritoneal dialysis-related peritonitis and high-dose Kalimate in a 59-year-old female patient. The patient had a history of hypertension, diabetes mellitus, and end-stage renal disease (ESRD). During hospitalization for peritoneal dialysis-related peritonitis, she developed hyperkalemia, and Kalimate was administered orally. However, severe abdominal distension and pain occurred just one day after Kalimate intake. An urgent surgery disclosed several perforations in the ileum and sigmoid colon. Pathology of the resected gut showed transmural necrosis and perforation with basophilic angulated crystals. The patient finally expired during hospitalization due to refractory septic shock.

AAGL Practice Report: Practice Guidelines for the Management of Hysteroscopic Distending Media: (Replaces Hysteroscopic Fluid Monitoring Guidelines. J Am Assoc Gynecol Laparosc. 2000;7:167-168.).

The objective of this guideline is to provide clinicians with evidence-based information about commonly used and available hysteroscopic distending media to guide them in their performance of both diagnostic and operative hysteroscopy. While necessary for the performance of hysteroscopy and hysteroscopically-directed procedures, distending media, if absorbed systemically in sufficient amounts, can have associated adverse events, including life-threatening complications. Consequently, understanding the physical properties and the potential risks associated with the use of the various distending media is critical for the safe performance of hysteroscopic procedures. This report was developed under the direction of the Practice Committee of the AAGL as a service to their members and other practicing clinicians.

[Pneumatosis intestinalis in anorexia nervosa: a case report]. / Ein Fallbericht einer Pneumatosis intestinalis bei Anorexia nervosa.

Pneumatosis intestinalis (PI) is identified as the accumulation of gas within the wall of the small or large intestine. It was first described by Du Vernoi in 1783. The pathogenesis is supposed to be multifactorial. It is assumed that there are 3 paths of disease development: mechanical, bacterial and biochemical. Adult patients are mostly asymptomatic and PI is diagnosed frequently by different radiological methods. The treatment of patients depends on their clinical picture. Most patients can be treated only with antibiotics and elemental diet. In a small number of cases, surgical intervention is essential. We report about a 35-year-old female patient with anorexia nervosa who developed PI after an excessive use of chewing gum for 3 years.

Association of prescription of oral sodium polystyrene sulfonate with sorbitol in an inpatient setting with colonic necrosis: a retrospective cohort study.

BACKGROUND: Colonic necrosis has been reported after sodium polystyrene sulfonate (SPS)/sorbitol use, but the incidence and relative risk (RR) are not established. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: 123,391 adult inpatients at a tertiary medical center. PREDICTOR: Receipt of SPS prescriptions (exposed) or a prescription other than SPS (unexposed internal comparison group) between September 1, 2001, and October 31, 2010. OUTCOMES: The main outcome measure was tissue-confirmed diagnosis of colonic necrosis, considered SPS-associated if SPS was prescribed 30 or fewer days before tissue accession date. MEASUREMENTS: Demographics, serum chemistry test results, hospital location, and International Classification of Diseases, Ninth Revision diagnostic codes. RESULTS: SPS was prescribed to 2,194 inpatients. 82 inpatient colonic necrosis cases were identified. 3 received oral SPS (1 gram per 4 milliliters of 33% sorbitol) 30 or fewer days before the colonic necrosis accession date (3.7% of inpatient colonic necrosis cases). The data were linked with 123,391 individuals who received inpatient prescriptions between the same dates. Colonic necrosis incidence was 0.14% (95% CI, 0.03%-0.40%) in those prescribed SPS versus 0.07% (95% CI, 0.05-0.08%) in those not prescribed SPS (RR, 2.10; 95% CI, 0.68-6.48; P = 0.2). The number needed to harm was 1,395 (95% CI, 298-5,100). Subgroup analysis (age >65 years; estimated glomerular filtration rate, <30 mL/min/1.73 m(2), intensive care unit admission, or surgical ward status) did not show significant associations. Sample-size analysis indicated that 4,974 SPS-treated individuals older than 65 years and a comparison group 10 times larger would be required for rigorous multivariate analysis of SPS-associated colonic necrosis risk. LIMITATIONS: Individuals with colonic necrosis admitted to non-Department of Defense hospitals would not have been ascertained. Only individuals who had colonic biopsy or surgical tissue submitted for pathologic review could be ascertained as having colonic necrosis. CONCLUSIONS: SPS-associated colonic necrosis is rare, and inpatient SPS/sorbitol prescription was not associated significantly with an increased RR of colonic necrosis in this retrospective cohort analysis. Multivariate analysis would require retrospective clinical cohorts from larger or more than one hospital system(s).

Colonic necrosis in a young patient receiving oral kayexalate in sorbitol: case report and literature review.

Kayexalate (sodium polystyrene sulfonate) is a cation-exchange resin used to treat patients with hyperkalemia. Concomitant administration of kayexalate and sorbitol may induce gastrointestinal injury, which is potentially lethal. However, this well-documented complication is often underrecognized both clinically and pathologically. We propose a typical case along with colonoscopic photos and microscopic pictures. Additionally, we also present a review of the literature on this rare drug-induced side effect.

How safe is the intravasation limit in hysteroscopic surgery?

BACKGROUND: Transcervical resection of myomas (TCR-M) is considered a safe hysteroscopic procedure if intravasation is limited. Complications may occur if gas formation during myoma resection leads to gaseous embolism. However, the incidence of emboli during transcervical myoma resection is unknown. Therefore in this study the occurrence of physiological changes that indicate the formation of emboli was retrospectively determined in patients undergoing hysteroscopic myoma resection. In addition, these changes were related to the amount of fluid intravasation. METHODS: The anesthesia records and operation files of 234 patients were screened for physiological changes that indicate embolism, as measured with standard intraoperative monitoring. These patients underwent surgery for intrauterine myomas with either a monopolar resectoscope with electrolyte-free distension fluid containing 3% sorbitol (limited to 1500-mL intravasation) or a bipolar resectoscope with normal saline solution (limited to 2500-mL intravasation). The patients were grouped according to the amount of fluid intravasation during the operation: Group 1: 500 mL or less, group 2: 500-1000 mL, group 3: 1000-1500 mL, and group 4: 1500-2500 mL. RESULTS: Physiological changes that could be attributed to gaseous embolism were observed in 33% to 43% of patients with 1000 to 2500 mL fluid intravasation during transcervical myoma resection. Nearly half of those patients had cardiovascular disturbances that indicated the formation of emboli. CONCLUSION: During transcervical resection of myomas, physiological changes that could be attributed to gaseous embolism frequently occurred. Therefore cardiovascular disturbances that indicate gaseous embolism during transcervical resection of myomas may occur despite the limitation of intravasation according to current view.

Damned if you do, damned if you don't: potassium binding resins in hyperkalemia.

Sodium polystyrene sulfonate (SPS) potassium binding resins increase colonic potassium excretion and are approved by the U.S. Food and Drug Administration (FDA) for the treatment of hyperkalemia. In 2009, the FDA recommended that sorbitol, a cathartic often given with SPS to prevent obstipation, not be added to SPS powder because of associated colonic necrosis. A premixed oral suspension of SPS in 33% sorbitol was not included in this warning. SPS resins increase stool potassium excretion in normokalemic subjects, but proportionately more potassium is excreted due to cathartics when the two are combined. In hyperkalemic patients, oral SPS mixed in water significantly decreases serum potassium within 24 hours. SPS/sorbitol-associated colonic necrosis is most commonly seen in patients who have received enemas in the setting of recent abdominal surgery, bowel injury, or intestinal dysfunction. It is a rare event, on the order of 0.2 to 0.3%, almost exclusively present in patients at risk. The agent most likely associated with colonic necrosis is 70% sorbitol, and animal data support that etiology. There is very little data to suggest that oral SPS given with 33% sorbitol (in the premixed form) or SPS powder in water orally or as an enema causes colonic necrosis. SPS ion-exchange resins are the only agents, other than dialysis and diuretics, available to increase potassium excretion in hyperkalemia, and when used appropriately, they appear to be clinically effective and reasonably safe.

Severe hypocalcemia caused by absorption of sorbitol-mannitol solution during hysteroscopy.

Hysteroscopic procedure can be complicated by intravascular absorption of irrigating fluid. The clinical features of this complication are similar to transurethral resection of the prostate (TURP) syndrome. There have been few reports on hypocalcemia during endoscopic surgery and clinical implications of hypocalcemia in TURP syndrome have been underestimated. We report a case of TURP syndrome association with a decreased ionized calcium concentration of 0.53 mM/L after the absorption of a large amount of sorbitol-mannitol solution during hysteroscopy. The hypotension which occurred in TURP syndrome did not respond to vasopressor and inotropic agent but responded to the administration of calcium. This case was also accompanied by hyponatremia, hyperglycemia and lactic acidosis through the metabolism of sorbitol.

Successful treatment of a colonic ulcer penetrating the urinary bladder caused by the administration of calcium polystyrene sulfonate and sorbitol.

A 77-year-old woman was urgently admitted for the treatment of diabetic ketoacidosis and a duodenal ulcer hemorrhage in March 1999. She had a history of diabetes and angina pectoris. After admission, she received oral calcium polystyrene sulfonate and sorbitol to treat hyperkalemia. Nine days later, severe abdominal pain developed. A colonoscopic examination revealed a sigmoid colonic ulcer and stenosis; the patient was treated conservatively. At a 1-year follow-up examination, the colonic stenosis was found have worsened; pneumaturia developed in January 2001. The patient was found to have a sigmoidovesical fistula and underwent sigmoidectomy and partial resection of the ileum and urinary bladder. The histological findings were a benign colonic ulcer with the infiltration of inflammatory cells, mainly lymphocytes. Rhomboidal, dark violet Kayexalate crystals were observed on microscope examination in the submucosa in both the first and second colonic biopsy specimens. We concluded that the colonic ulcer and the sigmoidovesical fistula had been caused by the administration of calcium polystyrene sulfonate and sorbitol. Reports of colonic perforation as a result of the administration of calcium polystyrene sulfonate and sorbitol are rare. Here, we report the successful treatment of a colonic ulcer that had penetrated the urinary bladder.

Investigation of often-reported ten percent hysteroscopy fluid overfill: is this accurate?

STUDY OBJECTIVE: A key component of hysteroscopic complications, such as fluid overload and severe dilutional hyponatremia, is the failure to anticipate and quickly recognize fluid deficits. The purpose of this study was to measure the volume and mass of irrigation fluid bags to assess the overfill of 3 common types of hysteroscopy irrigation fluids, 0.9% normal saline solution, 3% sorbitol, and 1.5% glycine, to challenge the often-quoted standard of assumption that overfill may be as high as 10% of the bag's volume. DESIGN: Ten cases of irrigation fluid were tested. The volume and weight of drained fluid from 18 bags of 0.9% normal saline solution 2000 mL, 12 bags 3% sorbitol 3000 mL, 8 bags of 1.5% glycine 3000 mL, and 4 bags of 0.9% normal saline solution 5000 mL were measured. Institutional review board exemption was obtained. MEASUREMENTS AND MAIN RESULTS: Ten cases of irrigation fluid were obtained. The volume and weight of drained fluid from 18 bags of 0.9% normal saline solution 2000 mL, 12 bags of 3% sorbitol 3000 mL, 8 bags of 1.5% glycine 3000 mL, and 4 bags of 0.9% normal saline solution 5000 mL were measured. By volume, varying by the type of fluid tested, the maximum observed overfill was between 3.3% to 5.0%. For confirmation, each bag was also weighed and found to have a maximum overfill between 2.8% to 5.6%, varying with the volume and type of fluid measured. These findings were then compared with the manufacturer-provided overfill range of 1.5% to 6.0%. No underfill was observed. CONCLUSION: Contrary to assertions over the last 25 years that overfill is 10% or higher as a rule, it appears more reasonable to assume that the degree of overfill is contingent on the type and volume of fluid used and is more likely closer to 2.8% to 5.6%. Therefore an accurate collecting system and weight measurement is more precise.