Severe Respiratory Alkalosis during Hemodialysis.

Respiratory alkalosis during hemodialysis session is a rare complication. We managed two patients with severe respiratory alkalosis, a woman who developed this 75 min after the beginning of the session and a man who developed it about 1 h before the end of the session. In both, the cause was a hypotensive episode, and both hypotension and alkalosis were successfully treated.

A case report on the placement of a temporal dialysis catheter in the femoral artery for emergency dialysis.

Background: Ensuring vascular access is essential for dialysis patients. This can be achieved through an arteriovenous anastomosis (fistulae), a central venous catheter, or an arteriovenous graft. However, in some cases vascular access to the patient's blood is not possible. Case Presentation: A multi-vascular male patient, who had been undergoing dialysis for 17 years, was presented to our renal department. There was no possibility of vascular access to the patient's venous network for dialysis. A peritoneal dialysis catheter was inserted, but it was malfunctioning. An attempt was made to place a HeRO AV Graft, but it did not succeed due to contraindications from the patient's venous network, as shown by the computed tomography. While trying to solve the problem in order to dialyze the patient during his hospitalization, he experienced severe shortness of breath with tachypnea (pulmonary edema), along with acidosis and hyperkalemia. A temporal dialysis catheter was urgently inserted into the left femoral artery and isolated ultrafiltration was performed, and by removing 1500 ml of ultrafiltration, the patient improved significantly. During the subsequent days, he underwent another 11 dialysis sessions using the femoral artery catheter. While he was hospitalized and being dialyzed via the femoral artery, a successful effort was made to catheterize the right external jugular vein, from which he continues to be dialyzed today. Conclusion: The patient's treatment through the placement of a temporal dialysis catheter in the femoral artery enabled him to survive. It is our belief that such a solution could be helpful in similar cases.

Prevalence of Apparent Treatment-Resistant Hypertension in ESKD Patients Receiving Peritoneal Dialysis.

BACKGROUND: Apparent treatment-resistant hypertension (aTRH) is defined as failure to achieve adequate blood pressure (BP) control despite taking ≥3 antihypertensive medications from different categories or when taking ≥4 antihypertensives regardless of BP levels. METHODS: In this cross-sectional study, we estimated the prevalence of aTRH in 140 patients receiving long-term peritoneal dialysis (PD) in four centers of Northern Greece, using the "gold-standard" method of ambulatory BP monitoring for the assessment of BP control status. The presence of subclinical overhydration was evaluated with the method of bioimpedance spectroscopy (BIS). RESULTS: Incorporating the diagnostic threshold of 130/80 mmHg for 24-hour ambulatory BP, the prevalence of aTRH in the overall study population was 30%. Compared to patients without aTRH, those with aTRH tended to be older in age, had higher PD vintage, had higher dialysate-to-plasma creatinine ratio, had more commonly history of diabetes mellitus, and were more commonly current smokers. With respect to the volume status, the overhydration index in BIS was higher in those with versus without aTRH (2.0 ±â€…1.9 L vs. 1.1 ±â€…2.0 L, P < 0.05). The prevalence of volume overload, defined as an overhydration index in BIS > 2.5 L, was also higher in the subgroup of patients with aTRH (38.1% vs. 18.4, P = 0.01). CONCLUSION: The present study showed that among patients on PD, the prevalence of aTRH was 30%. However, 38% of PD patients with aTRH had subclinical overhydration in BIS, suggesting that the achievement of adequate volume control may be a therapeutic opportunity to improve the management of hypertension in this high-risk patient population.The present study showed that among patients on PD, the prevalence of aTRH was 30%. However, 38% of PD patients with aTRH had subclinical overhydration in BIS, suggesting that the achievement of adequate volume control may be a therapeutic opportunity to improve the management of hypertension in this high-risk patient population. CLINICAL TRIALS REGISTRATION: Trial Number NCT03607747.

Prevalence, recurrence and seasonal variation of hyperkalemia among patients on hemodialysis.

PURPOSE: Observational studies have shown that among patients on hemodialysis, hyperkalemia is strongly associated with excess risk for cardiovascular-related hospitalizations and sudden cardiac death. However, the actual burden of hyperkalemia, the rates of its recurrence and seasonality in its variation still remain unclear. METHODS: Between June 2020 and May 2021, 1786 mid-week pre-dialysis serum potassium (sK) measurements were retrospectively recorded from 149 patients receiving thrice-weekly hemodialysis in a single-center in Thessaloniki, Greece. The prevalence, recurrence and seasonal variation of hyperkalemia were assessed using three pre-specified sK thresholds (≥ 5.1, ≥ 5.5 and ≥ 6.0 mmol/L). RESULTS: At baseline, 60.4%, 42.2% and 13.4% of patients had sK levels ≥ 5.1, ≥ 5.5 and ≥ 6.0 mmol/L, respectively. At any time-point during follow-up, 85.2%, 69.8% and 38.9% of patients experienced at least one hyperkalemic event ≥ 5.1, ≥ 5.5 and ≥ 6.0 mmol/L, respectively. Of the 104 patients experiencing an initial sK elevation ≥ 5.5 mmol/L, hyperkalemia at the same threshold reoccurred in 60.6% at month 1, in 47.1% at month 2 and in 46.1% at month 3 of follow-up. Seasonal variation was also observed, with the prevalence of hyperkalemia to be significantly higher in summer. Shorter delivered hemodialysis < 4 h/session (OR: 2.568; 95% CI 1.045-6.313) and the use of a high dialysate K concentration (OR: 14.646; 95% CI 2.727-78.647) were the 2 factors that were independently associated with hyperkalemia. CONCLUSION: The present study shows that among hemodialysis patients, the rates of hyperkalemia prevalence and recurrence are very high, reflecting the large unmet need to identify more effective potassium-lowering therapeutic interventions in this high-risk population.

The prevalence of HCV RNA positivity in anti-HCV antibodies-negative hemodialysis patients in Thrace Region. Multicentral study.

INTRODUCTION: HCV infection in patients under hemodialysis for end stage chronic kidney disease (ESCKD) may exist despite the absence of anti-HCV antibodies. Molecular methods are widely accepted as "gold standard" techniques for the detection of viral RNA. However, the molecular methods are more expensive in comparison to conventional methods and their replacement is not cost-effective. The aim of this study was to estimate the prevalence of HCV RNA positivity in anti-HCV negative hemodialysis patients and evaluate new diagnostic methods for the detection and the monitoring of hepatitis C in ESCKD patients. METHODS: The study was performed in four hospitals of Thrace region of Greece and 233 patients with no history of hepatitis C were enrolled. Measurement of anti-HCV antibodies and HCV core antigen was performed by microparticle chemiluminescence immunoassay. Molecular detection of viral RNA was performed by the real-time RT PCR. RESULTS: The mean age of the patients was 64.9 ± 23.3 years. HCV-Ag was positive in 2/233 patients (0.86%). Nevertheless, viral RNA was negative in those patients. CONCLUSIONS: The results of the present study showed that the incidence of HCV-RNA in patients with negative anti-HCV Abs, in hemodialysis patients in Thrace region of Greece was negligible (0/233).

Reversed connection of cuffed, tunneled, dual-lumen catheters with increased blood flow rate maintains the adequacy of delivered dialysis despite the higher access recirculation.

PURPOSE: Reversing the connection mode of permanent dual-lumen dialysis catheters results in higher access recirculation that may compromise the dialysis adequacy. The purpose of this study is to investigate the effect of reversed-connected dialysis with a higher versus a standard blood flow rate (Qb) on adequacy parameters and access recirculation. MATERIALS AND METHODS: In a cross-over design, 46 prevalent dialysis patients with a properly functioning cuffed, tunneled, dual-lumen catheter were evaluated in three consecutive mid-week dialysis sessions. At baseline, participants were evaluated under standardized conditions (correct connection, Qb = 300 ml/min). In Phase A, dialysis was performed with reversed connection and Qb = 300 ml/min. In Phase B, dialysis was performed with reversed connection and Qb = 400 ml/min. The sequence of evaluations (Phase A and B or vise verse) was randomized. All other dialysis-related parameters were unchanged in all three occasions. RESULTS: As expected, compared with baseline, reversed-connected dialysis in Phase A resulted in lower URR and spKt/V, and in a higher recirculation rate. Compared with baseline, reversed-connected dialysis with a higher Qb in Phase B resulted in an even higher recirculation rate, but the parameters of dialysis adequacy were not different. Increase in Qb from 300 to 400 ml/min resulted in an improvement of the dialysis adequacy (URR: 64.1 ± 7.8% vs. 70.6 ± 8.2%, P < 0.001; spKt/V: 1.22 ± 0.3 vs. 1.45 ± 0.3, P < 0.001) despite the higher recirculation rate. CONCLUSION: This study suggests that reversed-connected dialysis with increasing Qb maintains the adequacy of the delivered dialysis despite the compensatory increase in recirculation.

Blood pressure variability is increasing from the first to the second day of the interdialytic interval in hemodialysis patients.

OBJECTIVES: Patients with end-stage renal-disease under hemodialysis have increased cardiovascular risk and experience severe blood pressure (BP) fluctuations during the dialysis session and the subsequent interdialytic period. BP variability (BPV) may be an additional risk factor for cardiovascular events and preliminary data suggest increased BPV with advancing stages of chronic kidney disease. This is the first study to examine BPV during the whole intradialytic and interdialytic period in hemodialysis patients with ambulatory BP monitoring. METHODS: A total of 160 patients receiving maintenance hemodialysis had 48-h ambulatory BP monitoring with the Mobil-O-Graph device during a regular dialysis session and the subsequent interdialytic interval. Brachial and aortic BPV were calculated with validated formulas and were compared between Days 1 and 2 of the interdialytic period (44-h), Days 1 and 2 of the total 48-h interval (including the dialysis session), and between the two respective daytime periods and night-time periods. RESULTS: All brachial SBPV indices [SD: 14.75 ±â€Š4.38 vs. 15.91 ±â€Š4.41, P = 0.001; weighted SD: 13.80 ±â€Š4.00 vs. 14.89 ±â€Š3.90, P < 0.001; coefficient of variation (CV): 11.34 ±â€Š2.91 vs. 11.93 ±â€Š2.94, P = 0.011; average real variability (ARV): 11.38 ±â€Š3.44 vs. 12.32 ±â€Š3.65, P < 0.001)] were increasing from Days 1 to 2 of the 44-h interdialytic period. Similarly, all indexes of DBPV were significantly increased in Day 2, except for CV. Aortic SBPV and DBPV indices displayed a similar pattern. Furthermore, all studied brachial SBPV and DBPV indexes were also lower during daytimes 1 than 2 (systolic ARV 11.56 ±â€Š3.98 vs. 12.44 ±â€Š4.03, P = 0.002); systolic ARV was lower in night-time 1 compared with night-time 2 (11.20 ±â€Š5.09 vs. 12.18 ±â€Š4.66, P = 0.045). In multivariate regression analysis prehemodialysis SBP, age and diabetes were independently associated with increased SBP ARV. CONCLUSION: BPV is increased in interdialytic Day 2 compared with Day 1 in hemodialysis patients; this could be another mechanism involved in the complex cardiovascular pathophysiology and increased cardiovascular mortality of these individuals.

Evaluation of a novel brachial cuff-based oscillometric method for estimating central systolic pressure in hemodialysis patients.

BACKGROUND/AIMS: Elevated wave reflections and arterial stiffness, as well as ambulatory blood pressure (BP) are independent predictors of cardiovascular risk in end-stage-renal-disease. This study is the first to evaluate in hemodialysis patients the validity of a new ambulatory oscillometric device (Mobil-O-Graph, IEM, Germany), which estimates aortic BP, augmentation index (AIx) and pulse wave velocity (PWV). METHODS: Aortic SBP (aSBP), heart rate-adjusted AIx (AIx(75)) and PWV measured with Mobil-O-Graph were compared with the values from the most widely used tonometric device (Sphygmocor, ArtCor, Australia) in 73 hemodialysis patients. Measurements were made in a randomized order after 10 min of rest in the supine position at least 30 min before a dialysis session. Brachial BP (mercury sphygmomanometer) was used for the calibration of Sphygmocor's waveform. RESULTS: Sphygmocor-derived aSBP and AIx(75) did not differ from the relevant Mobil-O-Graph measurements (aSBP: 136.3 ± 19.6 vs. 133.5 ± 19.3 mm Hg, p = 0.068; AIx(75): 28.4 ± 9.3 vs. 30.0 ± 11.8%, p = 0.229). The small difference in aSBP is perhaps explained by a relevant difference in brachial SBP used for calibration (146.9 ± 20.4 vs. 145.2 ± 19.9 mm Hg, p = 0.341). Sphygmocor PWV was higher than Mobil-O-Graph PWV (10.3 ± 3.4 vs. 9.5 ± 2.1 m/s, p < 0.01). All 3 parameters estimated by Mobil-O-Graph showed highly significant (p < 0.001) correlations with the relevant measurements of Sphygmocor (aSBP, r = 0.770; AIx(75), r = 0.400; PWV, r = 0.739). The Bland-Altman Plots for aSBP and AIx(75) showed acceptable agreement between the two devices and no evidence of systemic bias for PWV. CONCLUSION: As in other populations, acceptable agreement between Mobil-O-Graph and Sphygmocor was evident for aSBP and AIx(75) in hemodialysis patients; PWV was slightly underestimated by Mobil-O-Graph.

Insertion of permanent hemodialysis catheters through the great saphenous vein.

INTRODUCTION: In patients with end stage renal disease when there is inability for the creation of a direct arterio-venous fistula or by using a graft, the insertion of a permanent hemodialysis catheter in a central vein ensures the conduction of hemodialysis. We present a technique of placing a permanent catheter in the inferior vena cava through the great saphenous vein without the use of a guide wire. PATIENTS-METHODS: Over the study period, 12 hemodialyzed patients, with a mean age of 73 years, were referred for placement of a dialysis catheter through the great saphenous veins. The procedure was performed under local anesthesia, ECG monitoring, and fluoroscopic control. The insertion of the tunneled hemodialysis catheters was accomplished with ease, through surgical exposure of the great saphenous vein, without the need for a guidewire. RESULTS: The hemodialysis catheter's function was assessed intraoperatively. No intraoperative or immediate post operative complications were noted while during the study period 3 thromboses and an infection were detected (0,95 per 1000 catheter days). The primary catheter patency rates were 92%, 84%, 54% at 30, 90 and 180 days respectively, varying from 28 to 845 days (mean±SD = 294 ± 243,3). CONCLUSION: The introduction of dialysis catheters in the inferior vena cava through the great saphenous vein is technically simple with rare complications and with higher patency rates compared to the traditional femoral approach.

Acid-base and electrolyte disorders in patients with diabetes mellitus.

Diabetes mellitus is the most common metabolic disorder in the community. The diabetics may suffer from acid-base and electrolyte disorders due to complications of diabetes mellitus and the medication they receive. In this study, acid-base and electrolyte disorders were evaluated among outpatient diabetics in our hospital. The study consisted of patients with diabetes mellitus who visited the hospital as outpatients between the period January 1, 2004 to December 31, 2006. The patients' medical history, age and type of diabetes were noted, including whether they were taking diuretics and calcium channel blockers or not. Serum creatinine, proteins, sodium, potassium and chloride and blood gases were measured in all patients. Proteinuria was measured by 24-h urine collection. Two hundred and ten patients were divided in three groups based on the serum creatinine. Group A consisted of 114 patients that had serum creatinine < 1.2 mg/dL, group B consisted of 69 patients that had serum creatinine ranging from 1.3 to 3 mg/dL and group C consisted of 27 patients with serum creatinine > 3.1 mg/dL. Of the 210 patients, 176 had an acid-base disorder. The most common disorder noted in group A was metabolic alkalosis. In groups B and C, the common disorders were metabolic acidosis and alkalosis, and metabolic acidosis, respectively. The most common electrolyte disorders were hypernatremia (especially in groups A and B), hyponatremia (group C) and hyperkalemia (especially in groups B and C). It is concluded that: (a) in diabetic outpatients, acid-base and electrolyte disorders occurred often even if the renal function is normal, (b) the most common disorders are metabolic alkalosis and metabolic acidosis (the frequency increases with the deterioration of the renal function) and (c) the common electrolyte disorders are hypernatremia and hypokalemia.

Metformin induced severe hypophosphatemia in a patient on hemodialysis.

A 67-year-old diabetic and hypertensive woman presented to us with very low serum phosphate levels (PO4⁻ =1.1 mg/dL) about 40 days after initiation of hemodialysis (HD). The phosphate binders were discontinued, because they were thought to be the cause of hypophosphatemia. However, the serum phosphate levels continued to remain low during subsequent follow-up visits over one month (PO4⁻⁻⁻ = 0.7 and 0.6 mg/dL respectively). The patient had been started on metformin hydrochloride (850 mg thrice a day) about 18 days after the beginning of HD. The drug was stopped immediately (approximately 50 days after it was started) and the serum phosphate levels increased progressively, reaching 4.3 mg/dL. During the period with hypophosphatemia, the patient suffered from very intense fatigue and weakness (she was unable to walk), anorexia, diarrhea and tenesmus. There were no features suggestive of rhabdomyolysis, hemolysis, low blood pressure or hypoglycemia; she had low white blood cell and platelet counts. The patient was in good clinical condition 2-3 days after the discontinuation of metformin and she recovered totally 15 days later. This case is presented due to its rarity as well as the observation that despite the patient having severe hypophosphatemia, she showed only side effects of metformin. Hypophosphatemia caused only intense fatigue and no other symptoms.

The red blood cell deformability in patients suffering from end stage renal failure on hemodialysis or continuous ambulatory peritoneal dialysis.

Anemia is the main problem for patients suffering from end stage renal disease (ESRD). This study aimed to determine whether the index of rigidity (IR), that shows red blood cells (RBCs) deformability and the possible IR disturbances can provide an explanation about the cause of anemia, in patients undergoing maintenance hemodialysis (HD) or on peritoneal dialysis. The IR was determined in 39 hemodialyzed patients, who were already in dialysis for a period of time ranging from 16 to 120 months (mean+/-SD=41.8 +/-24.1) (Group A). Furthermore, the IR was measured in 32 patients on continuous ambulatory peritoneal dialysis (CAPD), who were in CAPD for a period of time ranging from 6 to 60 months (mean+/-SD = 10.7+/-9.9) (Group B). Finally, the IR was determined in 17 normal individuals (group C). The RBCs IR was measured twice in group A (before and after the end of a hemodialysis session) and once in groups B and C. The IR was determined by hemorrheometry (method of filtration), using special equipment. In group A the IR was increased in comparison to the control group (C) (17.9+/-6.2 vs. 10.2+/-1.8, p<0.0001). This increase was even higher in the measurement at the end of the hemodialysis session (paired t-test, p < 0.0001). The RBCs IR in CAPD patients was significantly lower than that of HD patients (12+/-3.8 vs. 17.9+/-6.2, p<0.0001) and was not statistically different from the control group (12+/-3.8 vs. 10.2+/-1.8, p=0.068). It is concluded from the study that: 1) in HD patients occur disturbances in the deformability of the RBCs, that are worsened by the hemodialysis session; 2) the index of rigidity of RBCs is significantly higher in the HD patients than in CAPD patients; 3) in patients on CAPD, the disturbance of deformability of the RBCs was less in comparison to the control group, which however does not reach the statistically significant levels.

The effect of intense passive apnea in the acid-base balance and electrolytes.

The aim of this study was to investigate the disturbances of the acid-base balance and electrolyte disorders in healthy individuals in the greatest passive apnea (prior to apnea and prior to first inhalation). The changes of the acid-base balance, the serum potassium and calcium levels as well as the disturbances of the cardiac rhythm were studied in a group of 15 healthy males aged 18 to 41 years old. Seven individuals part of the original group participated in a second trial. Following the initial apnea trial the individuals were allowed to 2-3 free inhalations and a second passive apnea effort was performed. The same parameters were measured in the second effort. In the primary effort the apnea duration was 170 +/- 53 s (mean +/- SD). The results received prior to the effort and immediately before the end of the apnea (paired t-test), showed no significant changes in the blood pH. The PaCO2 increased significantly, the PaO2 decreased significantly, blood bicarbonate increased significantly, the hemoglobin oxygen saturation decreased significantly. In addition the serum potassium and calcium levels decreased significantly. In the subgroup (7 individuals) the second effort of apnea lasted 50-70 s and showed no significant changes in the blood pH. The same changes concerning PaCO2 and blood bicarbonate were observed in the first and second effort of passive apnea. The serum potassium and calcium levels as well as the hemoglobin oxygen saturation showed no significant changes. During the initial effort of apnea all men presented bradycardia, which was followed by tachycardia immediately after the end of the effort. One individual, whose effort lasted 290s suffered intense tachycardia, cyanosis, convulsions, and loss of consciousness. It is concluded that during an intense effort of passive apnea: (a) the blood PaCO2 is significantly increased, as well as the blood bicarbonates, (b) the PaO2, the hemoglobin oxygen saturation and the serum potassium and calcium levels are significantly decreased, (c) the cardiac rate is significantly decreased, and (d) the second effort of apnea, following immediately the initial one, is sorter in duration and produces similar or milder changes of the above parameters.

Urate homeostasis in polycystic kidney disease: comparison with chronic glomerulonephritic kidney.

Autosomal dominant polycystic kidney disease (ADPKD) might affect urate homeostasis and clearance. Renal tubular urate transport was studied by means of probenecid (PB) and pyrazinamide (PZA) tests in individuals with ADPKD and normal renal function as well as various degrees of renal failure (49 patients). Comparisons were made between polycystic and chronic glomerulonephritic kidney (CGNK), as well as with controls (men with normal renal function). Patients with ADPKD and normal renal function showed plasma urate levels within normal range and normal renal urate handling. In contrast higher plasma urate levels comparing to controls were found in patients with CGNK and normal renal function. During the evolution of renal failure ADPKD patients showed lower urate plasma levels and higher renal clearance as well as, fractional urate excretion, comparing to CGNK patients with the same degree of renal failure. In conclusion patients with ADPKD and normal renal function have normal urate handling and plasma urate levels within normal range. With increasing severity of disease and during evolution of renal failure CGNK patients showed higher urate plasma levels and lower clearances comparing to ADPKD patients. When renal disease becomes more advanced there was no difference in renal urate handling between ADPKD and CGNK patients.

The influence of l-carnitine supplementation on hematocrit and hemoglobin levels in patients with end stage renal failure on CAPD.

The influence of L-carnitine supplementation on hematocrit (Hct) and hemoglobin (Hb) levels, in patients suffering from end stage renal disease (ESRD) on maintenance hemodialysis, are well known from several studies. The data concerning the serum levels of carnitine, in patients with ESRD on continuous ambulatory peritoneal dialysis (CAPD) are contradictory, but most of them support that they are rather normal. In this study the effect of L-carnitine supplementation on Hct, and Hb levels were investigated in patients suffering from ESRD on CAPD. In the study 12 patients were included (5F, 7M), aged from 39 to 92 years old (median 65.5 years), who were on CAPD for more than 6 months (from 6 to 15 months, mean +/- SD = 8.6 +/- 3.6), with normal serum ferrum and ferritin levels at the beginning of the study. Two grams of L-carnitine/ day per os (Superamin, Vianex Hellas), were administered in all the patients and the serum ferrum levels were tried to be kept stable, by exogenous ferrum administration, during the study period. If the Hct levels were more than 36% per month the erythropoietin (rHuEpo) dose of the patient was decreased monthly at the half dose/week. The changes of Hct, Hb, ferrum and ferritin levels, as well as the Indice de Rigidite (IR) of the erythrocytes were recorded, before and after the first, second and third month of the study period. Finally, the rHuEpo dose/ patient was registered monthly before and during the study. During the observations, Hct (35.4 +/- 3.3 vs. 38.1 +/- 3.4, ANOVA, p < 0.03) and Hb levels (11.0 +/- 1.1 vs. 11.9 +/- 1, ANOVA, p < 0.01), were significantly increased. On the other hand, rHuEpo dose necessity/patient/week was decreased significantly (3,833 +/- 3326 vs. 1,292 +/- 1,712, ANOVA, p < 0.01), in order to succeed the target Hct level. Furthermore, red blood cells IR also appeared to have a significant decrease (16.6 +/- 7.4 vs. 13.0 +/- 3.9, paired t-test, p < 0.03). Finally, the ferrum and ferritin levels were stable during the study period. It was concluded, that in patients on, CAPD the per os L-carnitine supplementation decreased, the red blood cells IR which contributes to the: (a) Increase of Hct and Hb levels and (b) decrease of the patients rHuEpo dose/week.