Clinical Outcomes of Patients with Acute Myocardial Infarction Complicated by Severe Refractory Cardiogenic Shock Assisted with Percutaneous Cardiopulmonary Support

Purpose

Limited data are available on the role of percutaneous cardiopulmonary support (PCPS) for the treatment of acute myocardial infarction (AMI) patients with cardiogenic shock. We investigated the clinical outcomes and predictors of in-hospital mortality after PCPS in patients with AMI complicated by severe refractory cardiogenic shock.

Materials and Methods

From January 2004 to December 2011, we analyzed data from 96 consecutive AMI patients with cardiogenic shock assisted by a PCPS system. The primary outcome was in-hospital mortality. The predictors of in-hospital mortality were determined by a Cox proportional-hazards model.

Results

In-hospital mortality occurred in 51 (53.1%) patients and 58 (60.4%) patients were able to be weaned from PCPS. Cardiopulmonary resuscitation (CPR) was performed in 61 (63.5%) patients before PCPS initiation. On multivariate analysis, age ≥67 years [adjusted hazard ratio (HR), 4.74; 95% confidence interval (CI), 2.27-9.93; p<0.001], CPR (adjusted HR, 2.32; 95% CI, 1.11-4.85; p=0.03), lactate clearance for 48 hours <70% (adjusted HR, 2.50; 95% CI, 1.04-6.05; p=0.041), and unsuccessful revascularization (adjusted HR, 3.57; 95% CI, 1.85-6.90; p=0.002) were independent predictors of in-hospital mortality after PCPS in patients with AMI complicated by cardiogenic shock.

Conclusion

In spite of PCPS management, AMI patients complicated by severe refractory cardiogenic shock demonstrated high mortality. Older age, CPR, lower lactate clearance for 48 hours, and unsuccessful revascularization were independent predictors of in-hospital mortality.     

Percutaneous cardiopulmonary support for treatment of massive pulmonary embolism

 The management of massive pulmonary embolism remains difficult, particularly when cardiogenic shock is involved. In an attempt to rescue and maintain the preoperative circulatory condition, seven patients with acute pulmonary embolism were given percutaneous cardiopulmonary support (PCPS). The circulation, respiratory condition, and urinary output were all improved after PCPS induction. Two patients died of profound cardiogenic shock before the operation. Five patients underwent surgical embolectomy. Postoperatively, all patients who underwent embolectomy were continuously assisted with PCPS. The overall survival rate after PCPS induction was 42.9% (3/7), and the success rate of surgical embolectomy was 60% (3/5). One of the major complications associated with PCPS was bleeding, which can be associated with preoperative thrombolysis. The use of PCPS immediately resuscitated and stabilized the hemodynamic condition and allowed a successful emergency pulmonary embolectomy to be performed. Additionally, PCPS was effective for postoperative respiratory management, which is sometimes associated with reperfusion pulmonary edema. Received: March 13, 2002 / Accepted: July 25, 2002 Correspondence to:E. Tayama     

Acute hypothyroidism has no effect on pulmonary vascular resistance

Summary The effect of acute hypothyroidism on the pulmonary circulation was studied in 9 nonobese athyreotic patients by right heart catheterization at rest and during exercise. The patients were studied while they were hypothyroid 2 weeks after ceasing triiodothyronine treatment and while they were euthyroid on replacement therapy. At rest, pulmonary blood flow [4.0±0.6 l/min vs 5.8±1.0 l/min,p<0.01] and systolic pulmonary artery pressure [18±3 mmHg vs 23±2 mmHg,p<0.01] were lower when the patients were hypothyroid than when they were euthyroid. The mean and diastolic pressures in the pulmonary artery and the pulmonary capillary pressures were not different among the groups. Likewise, thyroid hormone levels had no significant effect on pulmonary vascular resistance [100±25 dyn-s-cm^–5 vs 90±23 dyn-s-cm^–5]. With supine exercise, pulmonary blood flow [10.1±1.6 l/min vs. 13.2±2.0 l/min,p<0.01], mean pulmonary artery pressure [25±6 mmHg vs 30±6 mmHg,p<0.02], and systolic pulmonary artery pressure [36±6 mmHg vs 44±8 mmHg,p<0.01] were lower when the patients were hypothyroid. The diastolic pulmonary artery pressure and the pulmonary capillary pressure were similar in both thyroid states. Again, thyroid deficiency had no effect on pulmonary vascular resistance [81±23 dyn-s-cm^–5 vs 76±24 dyn-s-cm^–5]. The lower systolic pressures in the pulmonary artery seen in hypothyroidism are probably due to the decreased systolic volume load of the pulmonary circulation. The data do not suggest that thyroid hormones play a role in the regulation of pulmonary vascular resistance.Abbreviations PVR pulmonary vascular resistance - PAP_M mean pulmonary artery pressure - PCP_M mean pulmonary capillary pressure - PBF pulmonary blood flow     

Venous drainage method for cardiopulmonary bypass in single-access minimally invasive cardiac surgery: siphon and vacuum-assisted drainage

Vacuum-assisted venous drainage (VAVD) can facilitate venous drainage in single-access minimally invasive cardiac surgery (SAMICS). We retrospectively examined the use of VAVD in SAMICS in our hospital for this report. VAVD has been performed according to a VAVD protocol since 2000. Data from the 110 patients who underwent SAMICS in our institute from January 2000 to June 2002 were reviewed retrospectively. The total negative pressure was maintained at no greater than −90 mmHg. Indications for use of VAVD (protocol) were: insufficient venous return by siphon drainage alone, persistent elevation of the central venous pressure (CVP), and, insufficient venous drainage in the operative field. Of 110 patients, 97 (88.2%) underwent VAVD. The body surface area was significantly smaller in the group that did not require VAVD (the non-VAVD group) than in the group that did (VAVD group) (VAVD group versus non-VAVD group: 1.586 ± 0.175 versus 1.408 ± 0.153 m², P < 0.001). Other factors such as cardiopulmonary bypass time, aortic cross-clamp time, postoperative maximum lactate dehydrogenase, postoperative maximum creatinine, postoperative maximum blood urea nitrogen were similar in the two groups. VAVD is necessary in SAMICS except for small patients. A VAVD total negative pressure of −90 mmHg did not hinder operative procedures or cause clinical problems.     

Naloxone in treatment of circulatory shock resistant to conventional therapy

Summary The effect of naloxone (4.4–5.9 mg i.v.) was evaluated in 10 patients with circulatory shock (sepsis,n=7; intoxication,n=1; cardiogenic shock,n=2) not responding to full conventional therapy. In addition, we measured plasma ACTH and immunoreactive -endorphin before and 60 min after administration of naloxone and compared the results with hormone concentrations in 10 intensive care patients without shock. Only in two patient with septic shock a transient increase (duration 15 min and 60 min, respectively) of systolic blood pressure was observed, while naloxone was ineffective in the remaining eight patients. No adverse effects of naloxone were found. Plasma ACTH and immunoreactive -endorphin concentrations in patients with shock were not different from those in controls (ACTH, 79±28 vs 120±60 pg/ml; immunoreactive -endorphin, 952±262 vs 1,070±378 pg/ml).Our findings suggest that naloxone in a single dose of 4.4–5.9 mg i.v. does not improve the management of circulatory shock unresponsive to conventional treatment. -endorphin seems to play no major role in the hypotension of shock.Abbreviations ACTH Adrenocorticotrophic hormone - HD intermittent hemodialysis - HF heart rate - ir immunoreactive - RR_syst systolic blood pressure Supported by Landesamt für Forschung, NRW     

Ist die Alpha-Adrenorezeptorendichte an intakten Thrombozyten bei statisch trainierten Athleten erhöht?

Summary Alpha-adrenoreceptors were determined as an equivalent to³H-dihydroergocryptine (DHE) specifically bound on intact thrombocytes in five untrained volunteers (I), eight non-staticly trained sportsmen (II), and eight intensively staticly trained athletes (III). B_max was 933±363 (I), 982±373 (II), and 1796±539 fmol DHE·10^–9 thrombocytes (III). K_D was 1.28±0.49 (I), 2.94±1.12 (II), and 3.58±1.07 nmol·1^–1 (III). The number of binding sites per cell amounted to 561±202 (I), 589±224 (II), and 1078±323 (III). The thrombocytes of the staticly trained athletes showed a significantly higher number of binding sites and a slightly higher affinity (K_D) than the other groups (p < 0.01). However, a wide range of overlapping has to be considered. The biologic significance of these results and their transferability to other organs are open at present. It is the question whether an altered adrenoreceptor density may be one factor of a higher prevalence of hypertension in staticly trained athletes on which our research group has reported recently.

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Abkürzungen B_max. maximale spezifische Bindung des Radioliganden, basierend auf dem Scatchard-Plot - K_D Dissoziationskonstante ermittelt aus der Scatchard Analyse - VO_{2 max.} maximale Sauerstoffaufnahmefähigkeit - DHE Dihydroergocryptin Mit Unterstützung des Bundesinstitutes für Sportwissenschaft, Köln-Lövenich     

Glomerular ultrafiltration in rabbits with superficial glomeruli

The determinants of glomerular ultrafiltration in superficial glomeruli of a strain of English cross-breed rabbits have been studied using micropuncture techniques. Mean arterial blood pressure in the anaesthetised rabbits was 70±2 mmHg. The glomerular filtration rate in the kidney prepared for micropuncture was 4.4±0.4 ml/min, the filtration fraction was 22±1% and renal blood flow was 33±3 ml/min, and these values were comparable to values in conscious rabbits. Glomerular capillary pressure (P _gc) averaged 31±1 mmHg, the single-nephron glomerular filtration rate (SNGFR) averaged 25±2 nl/min, and the mean ultrafiltration pressure (calculated using the whole-kidney filtration fraction) averaged 7±1 mmHg. A net positive pressure at the efferent end of the glomerular capillaries (4.4±0.9 mmHg) indicated that a state of filtration pressure disequilibrium existed, under the experimental conditions of this study, in rabbit glomeruli. The calculated glomerular ultrafiltration coefficient (K _f) was 0.08±0.01 nl s^–1 mmHg^–1. Thus, compared to the Munich-Wistar rat, SNGFR is lower in the rabbit. This reflects the substantially lower glomerular ultrafiltration pressure in the rabbit, although this was offset partially by a higher K_f.     

Adolescent girls with emotional disorders have a lower end‐tidal CO2 and increased respiratory rate compared with healthy controls

Hyperventilation has been linked to emotional distress in adults. This study investigates end‐tidal carbon dioxide (ETCO₂), respiratory rate (RR), and heart rate variability (HRV) in adolescent girls with emotional disorders and healthy controls. ETCO₂, RR, HRV, and ratings of emotional symptom severity were collected in adolescent female psychiatric patients with emotional disorders (n = 63) and healthy controls (n = 62). ETCO₂ and RR differed significantly between patients and controls. ETCO₂, HR, and HRV were significant independent predictors of group status, that is, clinical or healthy, while RR was not. ETCO₂ and RR were significantly related to emotional symptom severity and to HRV in the total group. ETCO₂ and RR were not affected by use of selective serotonin reuptake inhibitors. It is concluded that emotional dysregulation is related to hyperventilation in adolescent girls. Respiratory‐based treatments may be relevant to investigate in future research.     

Insertion/deletion polymorphism in the angiotensin-converting enzyme gene associated with macroangiopathy and blood pressure in patients with non-insulin-dependent diabetes mellitus

In the search for new risk factors for diabetic macroangiopathy the insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme gene was studied in 237 consecutive patients (125 men and 112 women) with non-insulin-dependent diabetes. The female population showed an excess of ischemic electro-cardiographic changes or definite myocardial infarctions in the patients homozygous for the deletion [D/D; odds ratio (OR) 2.8; 95% confidence interval (CI) 1.4–5.3] and in the insertion/deletion heterozygotes (I/D; OR 1.8; CI 1.1–3.1) compared with the patients homozygous for the insertion (I/I). In the total series coronary heart disease, cerebrovascular disease, and claudication were more often observed in the patients with I/D (OR 1.5; CI 1.0–2.2) or the D/D genotype patients (OR 1.7; CI 1.1–2.6) than in those with the genotype I/I. The systolic blood pressure was lower in patients with genotype I/I (138±19 mmHg) than in those with the genotype I/D (149±22 mmHg) or D/D (150±21 mmHg; P<0.02). The prevalence of hypertension and the median urinary albumin excretion rate also tended to be lowest in the I/I genotype patients. Multiple logistic analysis revealed that in women the angiotensin-converting enzyme D/D genotype is independently associated with coronary heart disease. Our findings suggest that variation at the angiotensin-converting enzyme gene locus is one of the factors involved in the predisposition of diabetic patients to the development of arterial disease and hypertension.Abbreviations ACE Angiotensin-converting enzyme - CHD Coronary heart disease - NIDDM Non-insulin-dependent diabetes mellitus     

Earliest Bedside Assessment of Hemodynamic Parameters and Cardiac Biomarkers: Their Role as Predictors of Adverse Outcome in Patients with Septic Shock

Background: Early assessment and aggressive hemodynamic treatment have been shown to increase the survival of patients in septic shock. Current and past sepsis guidelines recommend a resuscitation protocol including central venous pressure (CVP), mean arterial blood pressure (MAP), urine output and central venous oxygen saturation (ScvO₂) for resuscitation within the first six hours. Currently, the established severity score systems like APACHE II score, SOFA score or SAPS II score predict the outcome of critically ill patients on the bases of variables obtained only after the first 24 hours. The present study aims to evaluate the risk of short-term mortality for patients with septic shock by the earliest possible assessment of hemodynamic parameters and cardiac biomarkers as well as their role for the prediction of the adverse outcome.Methods: 52 consecutive patients treated for septic shock in the intensive care unit of one centre (Marien Hospital Herne, Ruhr University Bochum, Germany) were prospectively enrolled in this study. Hemodynamic parameters (MAP, CVP, ScvO₂, left ventricular ejection fraction, Hematocrit) and cardiac biomarkers (Troponin I) at the ICU admission were evaluated in regard to their influence on mortality. The primary endpoint was all-cause mortality within 28 days after the admission.Results: A total of 52 patients (31 male, 21 female) with a mean age of 71.4±8.5 years and a mean APACHE II score of 37.0±7.6 were enrolled in the study. 28 patients reached the primary endpoint (mortality 54%). Patients presenting with hypotension (MAP <65 mmHg) at ICU admission had significantly higher rates of 28-day mortality as compared with the group of patients without hypotension (28-day mortality rate 74 % vs. 32 %, p<0.01). Furthermore, the patients in the hypotension present group had significantly higher lactate concentration (p=0.002), higher serum creatinin (p=0.04), higher NTproBNP (p=0.03) and after the first 24 hours higher APACHE II scores (p=0.04). A MAP <65 mmHg was the only hemodynamic parameter significantly predicting the primary endpoint (OR: 4.1, CI: 1.1 - 14.8, p=0.008), whereas the remaining hemodynamic variables CVP, ScvO₂, Hematocrit, Troponin I and left ventricular ejection fraction (LVEF) seemed to have no influence on survival. Besides, non-survivors had a significantly higher age (74.1±9.0 vs. 68.4±6.9, p=0.01). If hypotension coincided with an age ≥72 years, the 28-day mortality rate escalated to 88%.Conclusions: In our study, we identified a risk group with an exceedingly high mortality rate: the patients with an age ≥72 years and presenting with hypotension (MAP <65 mmHg). These data can be easily obtained at the time of the very first patient contact. As a result, an aggressive and a more effective treatment can be initiated within the first minutes of the primary care, possibly reducing organ failure and short-term mortality in this risk group.     

Percutaneous cardiopulmonary support system as a bridge to left ventricular assist system (LVAS) implantation: Analysis of its role in the treatment of end-stage cardiac disease

The key to the successful implantation of a left ventricular assist system (LVAS) for patients with endstage cardiac disease is whether the functions of other vital organs are irreversibly damaged or not. The percutaneous cardiopulmonary support system (PCPS) is not only equal in convenience to the intra-aortic balloon pump (IABP), it is more powerful in resuscitating impaired end-organ function. To investigate the efficacy of PCPS for end-state cardiac disease, we retrospectively analyzed end-organ function before and after the application of PCPS. From 1992 to 1996, five cardiomyopathy patients with deteriorated end-organ function despite the application of IABP underwent PCPS support before implantation of LVAS. Urine volume and levels of liver enzymes (sAST and sALT) and serum creatinine were determined before and after the application of PCPS. After the application of PCPS, the urine output increased significantly (1840±450 to 4340±470 ml/day,P<0.01) and levels of sAST, sALT, and serum creatinine decreased significantly (630±220 to 150±50IU/l, 630±260 to 260±130IU/l, and 2.9±0.5 to 1.2±0.1 mg/dl, respectively) (P<0.05). All five patients were successfully bridged to LVAS implantation and none of them died of multiple organ failure caused by pre-existing cardiac failure although one out of five patients died on device ultimately. These results indicated that PCPS before LVAS implantation is useful to resuscitate impaired end-organ function and to improve the survival rate of LVAS implantation for end-stage cardiac disease.     

Resetting of renal autoregulation in conscious dogs: angiotensin II and alpha1-adrenoceptors

It has recently been shown, that common carotid occlusion (CCO) impairs autoregulation of renal blood flow (RBF) and glomerular filtration rate (GFR). This study was designed to investigate the mechanisms by which a moderate sympathetic stimulus influences RBF and GFR autoregulation. CCO provided a moderate sympathetic stimulus, and impaired autoregulation by increasing the lower autoregulatory limit of RBF and GFR by 21–30 mmHg. Basal RBF and GFR were not affected. A low-dose intrarenal infusion of the ₁-adrenoceptor agonist methoxamine (which did not change total RBF or GFR) induced a similar shift as CCO (n=5, RBF: +31±11 mmHg, P<0.05; GFR: +24±4 mmHg, P<0.01). In another group it was shown, that a combination of CCO with an intrarenal angiotensin II (A II) blockade (saralasin) did not significantly alter the response to CCO (n=7). These data suggest an ₁-adrenergic pathway for the sympathetic resetting of autoregulation. An augmented A II formation does not play a major role in mediating this effect.     

Intracellular pH during ischemia in skeletal muscle: relationship to membrane potential,extracellular pH,tissue lactic acid and ATP

Intracellular pH (pH_i) was measured with double-barrelled microelectrodes during 4 h of complete tourniquet ischemia in rabbit gastrocnemius muscle (group I). The pH_i was related to extracellular pH (pH_e), membrane potential (E_m), tissue lactic acid (LA) and ATP. A fall in pH_i from 7.00±0.03 to 6.60±0.05 occurred during 4 h of ischemia, with a slight pH-drop (0.07 pH units) during the initial hour and a more pronounced drop of 0.13 pH units during the last hour of ischemia. These changes were paralleled by a considerable decrease in pH_e from 7.30±0.01 to 6.36±0.05 and a sixfold increase of tissue LA. The buffering capacity during the 4 h of ischemia was estimated to 81.9±5.6 mmol H⁺/l×pH. In parallel with the reduction in pH_e, the resting membrane potential decreased from –90 mV and stabilised at around –60 mV after 2 h of ischemia. A less negative cell interior would favour H⁺ extrusion since the E_m-E_H ⁺ gradient was unchanged at about –70 mV during the entire period of ischemia. This could contribute to muscle fiber buffering during ischemia.In another set of experiments (group II) the muscular glycogen reserve was reduced 20 min prior to a 4 h period of ischemia. Thereby an ischemic state was created where ATP levels decreased to 30% of initial, in contrast to the unaltered ATP content in group I. In the low-ATP group II the E_m-E_H ⁺ gradient decreased to 58% of initial and the buffering capacity was slightly but significantly lower (64.6±4 mmol H⁺/l×pH) than in the high-ATP group I. Significant correlation coefficients were obtained between the ATP loss and the E_m-E_H ⁺ gradient (r=0.861,P<0.001). These data suggest that maintenance of the transmembrane H⁺ gradient and to a certain degree the buffer capacity depend on the energy-state of the muscle cell.     

Respiratory and cardiac responses to exercise — simulating peripheral perfusion in endurance trained and untrained rats

Summary Ventilatory and circulatory drives elicited by exercise-simulating perfusion of the circulatory isolated hindleg were examined in 10 trained (TR) and untrained (UTR) rats. TR were submitted to endurance training on a motordriven treadmill (30·min^–1 at a grade of 10%, 5 days a week for 30 min). Exercise was simulated by perfusion with modified tyrode solutions:I.) hypoxic, enriched with lactic acid (15 mmol·l^–1), II.) normoxic, enriched with lactic acid. III.) hypoxic without lactic acid. Perfusion was performed in anaesthetized animals through cannulae in the femoral artery and vein; the hindled was connected to the rest of the body only by nerve and bone. 10 min of control perfusion (normoxic tyrode solution) was followed by a 20 min test period and another 10 min control perfusion. Apart from heart rate (HR), respiratory rate (RR) and several outflow parameters were measured ([K⁺], [Na⁺], [lactate], pH, PO₂, PCO₂). During control periods HR was slightly higher in UTR than in TR (375.5±3.9 (SE) vs. 364.1±5.5 beats/min^–1,p<0.6 n.s.), and RR in UTR was significantly higher than those in TR (61.5±0.4 bpm vs. 55.5±3.9 breaths·min^–1,p<0.001). During the test periods both HR and RR in UTR increased significantly while in TR they did not (e.g. in series I mean HR and RR in UTR increased by 8.9±1.2 beats·min^–1 and 1.4±0.1 breaths·min^–1 respectively, whereas in TR the changes were-2.9±1.5 beats·min^–1 and -0.8±0.2 breaths·min^–1. A significant difference between UTR and TR can only partly be due to diminished venous [H⁺] caused by better H⁺ buffering in TR. Particularly in the tests with lactic acid, lactate was far above threshold level. It can be concluded that the metabolic stimulus and the afferent branch of the cardiorespiratory reflex have been attenuated by endurance training.Dedicated to J. Stegemann on the occasion of his 60^th anniversary     

Short-term effects of oral enoximone on hemodynamics,exercise capacity,anaerobic threshold,and arrhythmias in congestive heart failure

Summary Enoximone, a phosphodiesterase-inhibitor, is a potent inotropic vasodilator agent that causes a marked improvement in hemodynamics in patients with congestive heart failure. The acute effects of oral enoximone on rest and exercise hemodynamics, ejection fraction, aerobic metabolism, exercise capacity, and arrhythmias were studied in 11 patients with moderate to moderately severe dilative cardiomyopathy after 8 days of enoximone (100 mg tid) in addition to baseline therapy (diuretics and digitalis).The cardiac index increased from 2.44±0.45 to 2.72±0.50 l/min/m² (p<0.01) at rest and from 4.00±0.96 to 4.75±0.95 l/min/m² (p<0.005) during exercise. Pulmonary wedge pressure decreased from 16.8±7.3 to 12.5±6.5 mmHg (p<0.005) at rest and from 28.2±8.0 to 24.5±10.3 mmHg (p< 0.05) during exercise. Systemic vascular resistance decreased from 1608±243 to 1495±300 dynes*sec*cm^–5 (p<0.05) at rest and from 1152±155 to 1027±236 dynes*sec*cm^–5 (ns) during exercise. The anaerobic threshold, which was recorded simultaneously, increased from 13.2±2.7 to 15.5± 2.5ml/kg/min VO₂ (p<0.02). The radionuclide ventriculography ejection fraction improved from 21.7±5.0 to 28.1±9.1% (p<0.01) during exercise; the changes at rest were not significant (20.8±6.2 vs 25.8±8.4%). Exercise tolerance showed an increase of 16% (492±133 to 573±135 sec, p< 0.005). The resting heart rate remained unchanged (81.8±13.4 vs 81.8±11.9). Interestingly, 24-h Holter monitoring revealed more or new repetitive arrhythmias in 9/11 patients.Short-term therapy with oral enoximone enhances ventricular performance by increasing cardiac contractility and lowering vascular resistance, both of which extend exercise tolerance and improve aerobic metabolism. Potential proarrhythmic effects need further evaluation, however.Abbreviations AMP adenosine monophosphate - PDE phosphodiesterase - VCO₂ carbon dioxide production - VPB ventricular premature beat - VE minute ventilation - VO₂ oxygen uptake Dedicated to Professor Jahrmärker on the occasion of his seventieth birthday     

Potassium substitution via the oral route: Does its efficacy depend on the anion of the potassium salt?

Summary In an open, randomized study, we investigated the effect of oral potassium chloride (KCl) and of potassium citrate/bicarbonate (K-cit/bic) in 42 patients with hypokalemia (3.5 mmol/l). In both groups 80 mmol K⁺ were administered daily. The parameters examined were serum potassium concentration, acid-base status, and urinary electrolyte excretion. Parameters were evaluated on days 0, 2, 4, and 6. With KCl, [K⁺] increased from 3.2± 0.2 (mean± SD) on day 0 to 3.8± 0.4 mmol/l on day 2 (p<0.005) and 4.0± 0.5 mmol/l on day 4 (p< 0.005). On day 6 [K⁺] was also 4.0±0.4 mmol/l (p< 0.005 vs day 0). With K-cit/bic, [K⁺] increased from 3.2± 0.2 to 3.7± 0.4 on day 2, 3.9± 0.5 on day 4, and 4.1± 0.6 mmol/l on day 6 (allp< 0.005 vs day 0). The increase of [K⁺] was not different between the two groups. Blood pH on day 0 was in the normal range in both groups and did not change significantly during the study. There was a decrease of carbon dioxide partial pressure (pCO₂) with KCl from 38.7± 4.9 on day 0 to 36.4± 3.6 on day 2 (p<0.05). On days 4 and 6, pCO₂ was back up to the basal level. In contrast, with K-cit/bic, pCO₂ rose from 35.0±5.8 mmHg on day 0 to 39.9± 5.8 mmHg on day 2 (p< 0.05). On days 4 and 6, pCO₂ was not different from day 0. The increase in urinary potassium excretion was equal in both groups. These results indicate that oral substitution with either KCl or K-citrate/bicarbonate may have only minor effects on the acid-base status under the conditions of the present study. Both potassium salts appeared to be equally effective in correcting hypokalemia via the oral route.Abbreviations GFR glomerular filtration rate - K-bic potassium bicarbonate - K-cit potassium citrate - KCl oral potassium chloride - pCO₂ carbon dioxide partial pressure - t.i.d. three times a day     

Blood transfusion requirements in coronary artery surgery with and without the activated clotting time (ACT) technique

Summary Control of anticoagulation during cardiopulmonary bypass (CPB) with the automated activated whole blood clotting time (ACT) and reversal of heparin after CPB using a computerized ACT dose-response curve method resulted in significant reductions of blood transfusion requirements, surgical time, and protamine doses in 150 patients undergoing coronary artery bypass grafting procedures (ACT group) as compared to 200 patients for whom a standard fixed dose protocol for heparin and protamine was used (control patients). Mean transfusion requirements were 1,938±60 SEM ml whole blood and 853±48.3 SEM ml red blood cells for control patients and 1,397±59 SEM ml whole blood (P<0.001) and 695±34 SEM ml red blood cells (P<0.01) in the ACT group. ACT group patients also required less protamine with 26.2±0.60 SEM ml Protamine 1,000 (Roche) as compared to 33.9±0.49 SEM ml for control patients (P<0.001) but more heparin with 31,440±783 SEM I.U. versus 26,760±263 SEM I.U. (P<0.001). Surgical time decreased from 321±5.5 SEM min for control patients to 289±5.4 SEM min for ACT group patients (P<0.001).Abbreviations AB autologous blood - ACD right coronary artery - ACT activated clotting time - ACT_o ACT — before heparin administration - ACT₃₆₀ ACT — 5 min. after 360 I.U. heparin/kg body wt. - CPB cardiopulmonary bypass - Cx circumflex branch of the left coronary artery - DIAG diagonal branch of the left coronary artery - ECC extracorporeal circulation - FB fresh blood - FFP fresh frozen plasma - POD postoperative day - RBC red blood cells - RIA descending branch of the left coronary artery - RIP posterior descending branch of the right coronary artery - WB whole blood     

Gestörte alpha2-Adrenozeptorfunktion bei Hämodialysepatienten mit renaler Anämie — eine mögliche Ursache der Blutdrucksteigerung unter rekombinantem humanem Erythropoietin?

Summary Nine patients on maintenance hemodialysis and transfusion-demanding renal anemia (group A) were treated with rHuEPO 120 IU/kg i.v. three times per week. Hemoglobin-content was raised from 7.2±0.9 to 10.4±0.8 g/dl. In all patients blood pressure rose, three patients developed arterial hypertension. Mean diastoloic blood pressure was 66±12 and 78±16 mmHg (p<0.001) before and after rHuEPO. Rise in blood pressure was accompanied by a significant fall in plasma-noradrenaline-levels (from 498±100 to 383±75 pg/ml;p<0.05) and alpha₂-adrenoceptor-density (from 574±76 to 384±49;p<0.05). Compared to nine patients on maintenance hemodialysis and hematocrit over 30% (group B), patients with severe renal anemia (group A before treatment) had higher densities of alpha₂-adrenoceptors (574±76 vs. 218±32;p<0.001) despite higher plasma-noradrenaline-levels (498±100 vs. 399±63; n.s.). We suppose a anemia-related disturbance of alpha₂-receptor-function with the result of abolished receptor down-regulation and impaired vascular reagibility to vasoconstricting stimuli. With the correction of anemia receptor-function improves, receptor down-regulation as well as vascular reagibility is re-established resulting in augmented vascular resistance and higher blood pressure.

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Abkürzungen rHuEPO rekombinantes humanes Erythropoietin - teMAP mittlerer arterieller Blutdruck - RR Blutdrucknach RIVA-ROCCI - RBF regionaler Blutfluß - RPR regionaler peripherer Widerstand     

Platelet Na+/H+ antiport activity in patients with insulin-dependent diabetes mellitus with and without diabetic nephropathy

Summary The incidence of diabetic nephropathy in patients with insulin-dependent diabetes mellitus (IDDM) may depend on factors other than the quality of diabetes control. Hypertension is an additional factor associated with a high degree of renal involvement in IDDM. One abnormality consistantly observed in various tissues of patients with essential hypertension is enhanced activity of the Na⁺/H⁺ antiport. In the present study we have therefore studied platelet antiport activity in 41 healthy subjects (control), in 22 patients with untreated essential hypertension (EH), and in 35 normotensive IDDM patients (type 1). Of these patients 17 exhibited signs of diabetic nephropathy (group 1) while 18 had no evidence for renal involvement of IDDM in spite of a duration of IDDM of at least 10 years (group 2). The two IDDM patient groups were undistinguishable with respect to age, body mass index, and arterial blood pressure (group 1, 117.9±2.4/78.4±1.5 mmHg; group 2, 113.9±3.6/76.1±1.8 mmHg). Antiporter activity was determined from the rate of cell volume changes induced by propionic acid. Platelet Na⁺/H⁺ exchange activity averaged 23.43±0.43 10^–3·s^–1 in control subjects and was markedly elevated in EH (28.38±0.62 10^–3·s^–1 P<0.01). Antiport activity in group 2 patients without nephropathy averaged 24.54±0.57 10^–3·s^–1 and was undistinguishable from the control group. However, platelet Na⁺/H⁺ antiport activity was significantly stimulated in group 1 patients with nephropathy as compared to group 2(26.95±0.73 10^–3. s^–1 ; P<0.025). Our results show that renal involvement in IDDM is associated with enhanced activity of the platelet Na⁺/H⁺ antiport.Abbreviations EH essential hypertension - HbA_1c glycosyla-ted hemoglobin - IDDM insulin-dependent diabetes mellitus Dedicated to Prof. Dr. N. Zöllner on the occasion of his 70th birthday     

Patterns of central venous oxygen saturation,lactate and veno-arterial CO2 difference in patients with septic shock

Results:Of the 104 patients with circulatory shock, 79 patients (44 males) with septic shock aged 49.8 (standard deviation ± 14.6) years and with sequential organ failure assessment (SOFA) score of 11.0 ± 3.4 were included. 71 patients (89.9%) were ventilated (11.4 ± 12.3 ventilator-free days). The duration of hospitalization was 16.6 ± 12.8 days and hospital mortality 50.6%. Lactate significantly decreased over time with a greater decrement in survivors than nonsurvivors (−0.35 vs. −0.10, P < 0.001). For every l/min increase in cardiac output, vaCO₂ decreased by 0.34 mmHg (P = 0.006). There was no association between ScvO₂ and mortality (P = 0.930). 0 h SOFA and vaCO₂ ≤6 mmHg were strongly associated (P = 0.005, P = 0.018, respectively) with higher odds of mortality. However, this association was evident only in those with ScvO₂ >70% and not in ScvO₂ ≤70%.Conclusion:In septic shock, vaCO₂ ≤6 mmHg is independently associated with mortality, particularly in those with normalized ScvO₂ consistent with metabolic microcirculatory abnormalities in these patients.