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Biomedical subjects

W Hess

Publications and source records attributed to W Hess.

At least 19 recordsLinked to original sources
PubMed2000

[Primary cesarean section. Use of phenylephrine during anesthesia in a patient with hypertrophic obstructive cardiomyopathy].

We report on anaesthesia management for elective Caesarean section in a parturient woman with hypertrophic obstructive cardiomyopathy (HOCM). Special considerations for anaesthesia are associated with this condition. Women with HOCM need a closed diagnostic and therapeutic follow-up during pregnancy. Anaesthesiologists have to be aware of the cardiac peculiarities. Special risks may arise from endogenous catecholamine release during labour or from therapy with beta-adrenergic drugs for treatment of blood pressure drops or suppression of uterine contractions. Epidural anaesthesia is an appropriate anaesthesia method for Caesarean section, also in patients with HOCM. Adequate hemodynamic monitoring is essential. Phenylephrine is a pure alpha-adrenergic vasoconstrictor without inotropic effects. It is suitable for therapy of blood pressure drops induced by peripheral vasodilation.

Adult↗
PubMed2000

Prochlorococcus marinus Chisholm et al. 1992 subsp. pastoris subsp. nov. strain PCC 9511, the first axenic chlorophyll a2/b2-containing cyanobacterium (Oxyphotobacteria).

The formal description of Prochlorococcus marinus Chisholm et al. 1992, 299 was based on the non-axenic nomenclatural type, strain CCMP 1375T. The purification and properties of the axenic strain PCC 9511, derived from the same primary culture (SARG) as the type species, are reported here. Prochlorococcus PCC 9511 differs from the latter in possessing horseshoe-shaped thylakoids, exhibiting a low chlorophyll b2 content and lacking phycoerythrin, but shares these phenotypic properties with Prochlorococcus strain CCMP 1378. This relationship was confirmed by 16S rRNA sequence analyses, which clearly demonstrated that the axenic isolate is not co-identic with the nomenclatural type. Strain PCC 9511 has a low mean DNA base composition (32 mol% G+C) and harbours the smallest genome of all known oxyphotobacteria (genome complexity 1.3 GDa = 2 Mbp). Urea and ammonia are the preferred sources of nitrogen for growth, whereas nitrate is not utilized. Several different organic phosphorus compounds efficiently replace phosphate in the culture medium, indicative of ecto-phosphohydrolase activity. In order to distinguish strain PCC 9511 from the nomenclatural type, a new subspecies is proposed, Prochlorococcus marinus Chisholm et al. 1992 subsp. pastoris subsp. nov.

Bacterial Typing Techniques↗
PubMed1999

Incidence and prognosis of abdominal complications after cardiopulmonary bypass.

The incidence of abdominal complications after cardiopulmonary bypass is low but associated with a high mortality. From January 1991 to October 1996, 4288 patients, of a mean age of 62.5 years, underwent open-heart surgery. Fifty-nine (1 of 4) of these patients developed early abdominal complications. These included 36% with a paralytic ileus, 21% with erosive gastritis, 18% with upper gastrointestinal haemorrhage, 12% with intestinal ischaemia, 5% with pseudo-obstruction of the colon, 6% with acute cholecystitis and 2% with acute pancreatitis. After coronary artery bypass grafting mean cardiopulmonary bypass time was 94.4 min. There were abdominal complications in 1.0% and one hospital death. After valve surgery and combined surgery the mean cardiopulmonary bypass time was 129 min. There were abdominal complications in 2.4% (alpha = 0.01) and seven deaths. Fourteen patients (24%) underwent abdominal operations: three had caecostomies for pseudo-obstruction of the colon, seven had a hemicolectomy, two had a cholecystectomy and two had resection of the ventricle. The hospital mortality rate was 13.5%. Abdominal complications were significantly more frequent after valve or combined operations of the coronaries and valves in comparison with isolated coronary artery bypass grafting. Cardiac operations with extended cardiovascular bypass time were more likely to produce abdominal complications.

Abdomen, Acute↗
PubMed1999

[Diagnostic pneumology using model aerosols].

Clearance of Aerosol Particles from the Airways: Measurement of the efficiency and kinetics of particle clearance from the airways is dependent on the site of particle deposition within the lungs. Insoluble particles deposited in the alveolar region are mainly cleared by macrophages over a period of hundreds of days, whereas particles from the tracheobronchial airways are mainly cleared within hours or days by mucociliary clearance. We introduce a method for mucociliary clearance measurements called 'Radio-Bolus-Scintigraphy'. A small volume of radiolabelled aerosol particles sandwiched in clean air (aerosol bolus) is inhaled near the end of a tidal breath which leads to a preferential deposition of the particles in the airways. Particles were Fe3O4 labelled with 99mTc with an aerodynamic particle diameter of 3.5 microns (monodisperse). The retention of the particles within the lungs was detected by Gamma Camera and Human Scintillation Counter. 26 healthy subjects volunteered in this study (14 nonsmokers and 12 smokers). The half width of the mucociliary clearance was found to be 2.4 h in nonsmokers and 3.3 h in smokers (p < 0.05). Intersubject variability was small, 24 hours after inhalation 55% (+/- 6%) of the inhaled particles were still found in the airways of the subjects. No difference was found between nonsmokers and smokers. Good intersubject reproducibility makes this method useful in therapy control as well as in early diagnosis of changes in mucociliary clearance kinetics and efficiency.

Aerosols↗
PubMed1998

Johann Georg Wirsüng (1589-1643) and the pancreatic duct: the prosector of Padua, Italy.

Although his primacy was subsequently challenged by a student, it is now known that Johann Georg Wirsüng, the prosector of Padua, Italy, discovered the human pancreatic duct in 1642 during the dissection of an executed murderer. Instead of publishing his discovery, he engraved a drawing of the duct on a copper plate, from which he made seven or more imprints. The copies were sent to leading anatomists of Europe with the question, "Should I call it an artery or a vein? I never found blood in it ...." Three and a half centuries later, the copper plate remains well preserved and the authors, to the surprise of European surgeons and librarians, but with their aid, have traced six copies of the "ductus Wirsüngianus" imprints still in existence. This is the story of Wirsüng the man, his subsequent assassination, and finally the recognition that his finding had opened a new field of science.

Anatomy↗
PubMed1997

Prolonged oxygen debt after abdominal aortic surgery.

OBJECTIVE: The aim of the study was to investigate whether oxygen consumption and carbon dioxide production changed in the early postoperative period in the same manner in patients who underwent coronary artery bypass graft (CABG) surgery or abdominal aortic surgery (AAS). DESIGN: Prospective clinical study. SETTING: Single community hospital. PARTICIPANTS: Twenty-four patients (ASA II to III) who underwent elective abdominal aortic surgery and 49 patients (NYHA II, III) who underwent elective CABG surgery. INTERVENTIONS: In the ICU, oxygen consumption (VO2), carbon dioxide production (VCO2), and respiratory quotient (RQ) were continuously monitored with an indirect calorimetric device. Hemodynamic and metabolic parameters were measured during the first 3 hours. MEASUREMENTS AND MAIN RESULTS: In the early postoperative course, VO2 and VCO2 in the AAS group were significantly higher (p < 0.001), and the RQ was significantly lower during the first 90 minutes (p < 0.001). In the AAS patients, VO2 decreased with the postoperative increase of body temperature; whereas in the CABG patients, VO2 slightly increased. CONCLUSIONS: The high VO2 in the AAS patients observed during the early postoperative course can be explained by an oxygen debt that occurred as a result of clamping the aorta. It was presumed that the repayment of the debt was delayed and extended to the ICU stay because of thermoregulatory vasoconstriction. Abnormally low RQ values are probably a clue to repayment of an oxygen debt.

Adult↗
PubMed1997

[Abdominal complications after heart surgery interventions].

OBJECTIVE: Risk factors of abdominal complications after cardiac surgery are largely unknown. We undertook this study to determine different types of abdominal complications after cardiac surgery and to identify patients at risk. PATIENTS AND METHODS: 3312 adult patients were operated between Jan. 91 and Oct. 95 (2352 males, 960 females, 62.6 +/- 0.18y). We included all patients who suffered from abdominal complications within 30 days postoperatively. RESULTS: Abdominal complications are rare after cardiac surgery using cardiopulmonary bypass (CPB) (1.4%), but they are associated with high mortality (14.5%) in our department. Abdominal complications like paralytic ileus (43.8%), erosive gastritis (22.9%) and gastrointestinal bleeding (18.8%) are more often, compared with acute cholecystitis (14.5%), acute pancreatitis (8.3%) and intestinal ischemia (19.5%). Patients with intestinal ischemia are at high risk and do have a high mortality (83%). Abdominal complications can be found more often in connection with prolonged myocardial ischemia and valve replacement or combined operations. Prediction of complications on the basis of anamnestic data alone was not possible. CONCLUSION: Abdominal complications after cardiac surgery, especially intestinal ischaemia, are life-threatening. Prediction of abdominal complications is impossible. We have to concentrate on an early diagnosis and therapeutic intervention to lower mortality. A close cooperation between cardiac and general surgeons is mandatory for a successful treatment of life-threatening abdominal complications such as intestinal ischemia.

Adult↗
PubMed1997

Abdominal complications following cardiac surgery.

Type and frequency of abdominal complications after open heart surgery are described. Out of 3,312 patients, 48 patients (1.4%) developed early postoperative abdominal complications with a mortality rate of 14.5%. Paralytic ileus, erosive gastritis and gastrointestinal hemorrhage were the most frequent complications, whilst intestinal ischemia, acute cholecystitis and acute pancreatitis were less frequently observed. The comparison of the frequency of abdominal complications in cardiac surgery patients with the same complications in other operated patients showed no significant difference (hi-square test), with the exception of COLD which was more frequent in the group with abdominal complications. No association was found between perioperative treatment with aprotinine and the development of abdominal complications.

Cardiac Surgical Procedures↗
PubMed1995

[Cardiovascular diseases during pregnancy. Considerations for the anesthesiologist].

Pregnancy causes substantial changes in the cardiovascular system: cardiac output (40%-50%) and blood volume (40%) increase whereas systemic peripheral resistance and arterial pressure decrease. The rise in progesterone and estrogen levels accompanying pregnancy stimulates the renin-angiotensin-aldosterone system. Increased prostaglandin production follows renin activation; simultaneously, the arterial vessels show diminished angiotensin sensitivity. The result is pronounced vasodilatation. Cardiovascular diseases remain the most important nonobstetric cause of maternal death. The physiological changes in the cardiovascular system during pregnancy influence cardiac diseases in different ways. Pregnancy, labor, and delivery appear to be well tolerated in gravidae with an atrial septal defect, ventricular septal defect, and patent ductus arteriosus. Sometimes congestive heart failure occurs and appropriate medical therapy is necessary. Pregnant women with uncorrected cyanotic congenital heart disease (Eisenmenger's syndrome, tetralogy of Fallot) constitute a high-risk group because of right ventricular insufficiency and hypoxic attacks. The consequences for anaesthesia in parturients with congenital heart disease are discussed. The symptoms of acquired mitral or aortic stenosis are aggravated by the physiological changes in the cardiovascular system during pregnancy; the clinical symptoms of valve insufficiency are ameliorated by vasodilatation. Peripartum cardiomyopathy clinically shows similar features to idiopathic dilated cardiomyopathy. The basis of treatment is the same as that of congestive heart failure, with the therapeutic spectrum ranging from diet to heart transplantation. Women with hypertrophic cardiomyopathy tolerate pregnancy, labor, and delivery surprisingly well. Vaginal delivery is possible, but epidural anaesthesia is contraindicated. Hypertensive disorders associated with pregnancy are classified into three groups: chronic, transient, and pre-eclamptic hypertension. Whereas chronic and transient hypertension do not affect the outcome of pregnancy appreciably, pre-eclampsia presents a potential danger to mother and fetus. Pre-eclamptic hypertension is accompanied by low cardiac output and plasma volume. An upregulation of angiotensin receptors enhances vascular reactivity, with the consequence of high peripheral resistance. For antihypertensive therapy hydralazine, alpha-methyldopa, and magnesium sulfate are the drugs of choice. A generalised recommendation of anaesthesia for the pre-eclamptic gravida cannot be made because both general and epidural anaesthesia have risks of severe side effects.

Anesthesia↗
PubMed1994

[The effect of different types of anesthetic respirators on oxygenation and ventilation in infants during short-term anesthesia. A study using transcutaneous PO2 and PCO2 monitoring].

Monitoring of ventilation in infants is difficult and often not very reliable. In this study, transcutaneous measurement of blood gas tensions was used to investigate the influence of four different modes of ventilation on oxygenation and ventilation in anaesthetized infants. METHODS. In a randomised study, transcutaneously measured PO2 (tc-PO2) and PCO2 (tcPCO2) tensions were continuously registered in 42 ASA class I and II infants between 3 and 24 weeks of age undergoing minor surgical procedures (inguinal hernia repair). Two breathing systems combined with different modes of ventilation were evaluated: manual ventilation with Kuhn's T-piece system and face mask (group A; n = 11) or endotracheal tube (group B; n = 10); manual ventilation with paediatric circuit system and face mask (group C; n = 11); and mechanical ventilation with paediatric circle system, endotracheal tube, and positive end-expiratory pressure (PEEP) 3 cm H2O (group D; n = 10). Transcutaneous values were measured by a combined tcPO2/PCO2 electrode (E 5277, Radiometer). Anaesthesia was maintained by controlled ventilation with N2O/O2 (67%/33%) and halothane 0.5-1.5 vol.%. Surgical and anaesthetic techniques were standardized and the anaesthetist was blinded to the measured values. RESULTS. Preoperative mean tcPO2 values while spontaneously breathing air ranged between 69 and 75 mmHg in all patients. During anaesthesia and controlled ventilation (FiO2 = 0.33), there was a significant increase in tcPO2 (P < 0.01) in 3 groups: in groups A and D mean tcPO2 increased to 90-100 mmHg and in group C to 110-120 mmHg. In contrast, tcPO2 in group B reached only 75-80 mmHg, which was not considered significant. Postoperatively, tcPO2 immediately reached baseline values in all patients (Fig. 2). Compared to preoperative values, the alveolar-tcPO2 difference (AtcDO2) significantly increased during anaesthesia in all groups (Fig. 3). The tcPCO2 measurements revealed marked alveolar dysventilation, with hyperventilation supervening in groups A, B, and D; in group C, however, most (7 of 11) infants were normoventilated (Fig. 4). CONCLUSIONS. Adverse effects of anaesthesia on pulmonary function in infants are caused by loss of the PEEP effect induced by the physiological subglottic stenosis. Endotracheal intubation and the increase in chest wall compliance during anaesthesia lead to a decrease in functional residual capacity (FRC) associated with premature airway closure and ventilation/perfusion mismatch. These pathophysiological disturbances result in a marked increase in AaDO2 and low arterial PO2 values despite high FiO2, as could be observed when intubated infants had been ventilated with a high-flow T-piece system (group B). Mechanical ventilation with a paediatric circuit system and endotracheal tube allows the use of low PEEP levels (group D), which may replace the lost subglottic function and partially restore the FRC. Ventilation by mask does not disturb the functional subglottic stenosis, and the impairment of pulmonary function will depend solely on the decrease in FRC caused by increased chest wall compliance (group A). If mask ventilation is combined with a paediatric circuit system (group C), the pressure relief valve produces a low PEEP of 2 to 3 cm H2O, which may partially counteract the decrease in FRC. With regard to oxygenation, the paediatric circle system proved to be superior to the high-flow T-piece system independent of whether children were ventilated via a face mask or an endotracheal tube. The group-specific differences in degree of dysventilation with manual ventilation show that the type of breathing system is important with regard to the size of the tidal volume delivered. Thus, tidal volumes will be unintentionally increased by the high fresh gas flow needed when a T-piece system is used. The lower flow and preadjusted pressure limit may prevent the delivery of excessive tidal volumes with the paediatric circuit system...

Anesthesia↗
PubMed1993

[Effect of dopexamine on the hemodynamics of coronary surgery patients with and without bisoprolol blockade].

Patients with coronary artery disease undergoing coronary artery bypass grafting can develop perioperative low cardiac output failure requiring positive inotropic support. Commonly, the sympathetic amines, dopamine, dobutamine or adrenaline are used in low-output state. However, patients on long-term cardioselective beta-blocking therapy may experience problems with such a treatment. Dopexamine, a new synthetic amine, possesses positive inotropic effects by indirect stimulation of the beta 1-receptors and direct stimulation of the beta 2-receptors. We therefore studied the hemodynamic efficacy of dopexamine in patients with and without beta-receptor blockade. In 12 patients with coronary artery disease classed as NYHA II or III, six without any beta-blocker medication, and six with beta 1-blocker medication (bisoprolol 5 mg), anesthesia was induced with high-dose fentanyl (0.05 mg/kg) and pancuronium (0.1 mg/kg). The patients were normoventilated with a mask (O2:air 1:1, tidal volume 10 ml/kg with a rate of 10/min) for 5 min and then intubated. Following intubation anesthesia was continued with 0.025 mg/kg/h fentanyl. In anesthesia steady state the patients of both groups were treated with 2 micrograms/kg/min dopexamine over a period of 15 min and then with 4 micrograms/kg/min dopexamine over a further period of 15 min. Measurements of cardiovascular dynamics included heart rate (HR), cardiac index (CI), stroke volume index (SVI), mean arterial blood pressure (MAP), coronary perfusion pressure (CPP), systemic vascular resistance (SVR), pulmonary artery pressure (PAP), pulmonary capillary wedge pressure (PCWP), right atrium pressure (RAP), pressure work index (PWI) and arterial-mixed venous oxygen content difference (AVDO2), which were monitored or calculated by standard formulas.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Agonists↗
PubMed1992

[The concentration of atrial natriuretic peptides (ANP). ANP in different sections of the circulation during atrial volume load with and without anesthesia].

We studied the effect of a volume load induced by a 45 degrees Trendelenburg position on atrial natriuretic peptide (ANP) secretion in awake and anaesthetized patients with coronary artery disease undergoing aortocoronary bypass surgery. ANP was measured in different parts of the circulation before and after induction of high dose fentanyl anaesthesia at fixed times prior to and after extracorporeal circulation. METHOD. In eight patients with coronary artery disease (NYHA classification II-III), who received neither diuretic nor positive inotropic therapy, ANP was measured in the various parts of the circulation: in a peripheral vein, a radial artery, in the pulmonary artery and in the coronary sinus. The measurements were made in the supine and 45 degrees Trendelenburg position. Measurements of mean arterial pressure (MAP), central venous pressure (RAP), pulmonary arterial pressure (PAP), pulmonary capillary wedge pressure (PCWP), cardiac index (CI) and heart rate (HR) were taken simultaneously. The measurements were taken in the awake patient, during steady-state high-dose fentanyl anaesthesia with 50% O2 in N2O and after extracorporeal circulation. RESULTS. Compared to measurements in a control group, ANP levels were significantly higher in all parts of the circulation in patients with coronary artery disease, although clinical symptoms of heart failure were absent. After extracorporeal circulation, significantly higher levels of ANP were found at all measurement sites; however the concentration gradient of ANP between coronary sinus and arterial or venous blood was reduced. In awake and anaesthetized patients a change in body position, causing a significant increase in filling pressures, did not produce an increase in ANP levels at all measurement sites. The induction of high-dose fentanyl anaesthesia did not have an influence on plasmatic ANP levels. CONCLUSION. The results of this study lead to the following conclusions: 1. ANP levels in patients with CAD are increased, even if clinical heart failure symptoms are absent. 2. ANP is secreted in the coronary vessels. Following dilution in the atrial blood, it is metabolized to inactive compounds in the periphery. 3. Basic ANP levels are not changed by high-dose fentanyl anaesthesia. Marked increases of the filling pressures do not correlate with atrial ANP levels either before or after induction of anaesthesia. 4. After extracorporeal circulation ANP levels are significantly increased in all parts of the circulation. The concentration gradient between coronary sinus blood, on the one hand, and arterial and venous blood on the other hand is reduced. This phenomenon is probably caused by an alteration in the metabolism of ANP during hypothermic extracorporeal circulation.

Aged↗
PubMed1992

[Hemodynamics of coronary surgery patients following magnesium aspartate infusion].

Hypertension is a common phenomenon in patients undergoing aortocoronary bypass grafting. This hypertension increases myocardial oxygen consumption and can be prevented by application of vasodilators. A possible cause is activation of the renin angiotensin system. Magnesium is a potent vasodilator and has a beneficial effect after myocardial ischaemia. The study was performed to analyse the influence of magnesium infusion on the haemodynamic status and plasma renin activity in patients undergoing aortocoronary bypass grafting. METHODS. Eighteen patients (NYHA classification II-III) undergoing bypass surgery were divided into two groups, a magnesium and a control group. The magnesium group (n = 9) received 0.8 mEq/kg per h magnesium aspartate as an infusion for 15 min while still awake. After induction of anaesthesia, the magnesium infusion was reduced to 0.2 mEq/kg per h and stopped after aortic cannulation was completed. Plasma magnesium levels and concentrations within erythrocytes were measured. Anaesthesia was induced by flunitrazepam (0.01 mg/kg), fentanyl (0.005 mg/kg) and pancuronium (0.1 mg/kg). After intubation, patients were normoventilated with N2O/O2 = 1:1 and isoflurane (0.5-1.0 vol%). Additional doses of fentanyl (0.0025 mg/kg) were injected before the incision and before sternotomy. Mean arterial pressure, heart rate, cardiac index, total peripheral resistance, pulmonary vascular resistance, mean pulmonary arterial pressure, pulmonary capillary wedge pressure, left ventricular stroke work index, right ventricular stroke work index, intrapulmonary shunt and plasma renin activity were evaluated at five predefined points: (1) prior to magnesium infusion; (2) after magnesium infusion; (3) 10 min following induction of anaesthesia under steady-state conditions; (4) after sternotomy; (5) after aortic cannulation. RESULTS. Concerning the haemodynamic parameters (MAP, RAP, PAP, PCWP) no significant difference between the two groups could be demonstrated. In the control group peripheral resistance (TPR) was higher following sternotomy and aortic cannulation than in the magnesium group. Magnesium prevented decrease of the cardiac index (CI) under steady-state conditions, during sternotomy and following aortic cannulation. Left and right ventricular stroke work indexes (LVSWI and RVSWI) were higher in the magnesium group. Plasma renin levels were not significantly different between the two groups. CONCLUSION. Patients undergoing cardiac surgery benefit from magnesium administration in the pre-bypass phase. Due to its vasodilating effect, magnesium lowers the output impedance of the left ventricle and improves cardiac pumping function. It opposes detrimental cardiovascular responses to sternotomy and following aortic cannulation. Also of importance is the advantageous effect of magnesium on cardiac arrest elicited by cardioplegia and for reactivation of the ischaemic myocardium.

Aspartic Acid↗
PubMed1992

[Successful therapy of a cardiac arrest during accidental hypothermia using extracorporeal circulation].

We report the case of a 59-year-old woman suffering from profound accidental hypothermia promoted by intoxication with codeine, sedatives, and a beta-blocking agent ingested in a suicidal attempt. Treatment was further complicated by ventricular fibrillation and asystole that was refractory to therapeutic interventions. The comatose patient (Glasgow score 3) was found outdoors in rainy weather--environmental temperature approximately 10 degrees C (50 degrees F)--by children. The skin was rosy when the emergency team arrived. The respiratory rate was low and the ECG showed sinus rhythm with a heart rate of 28/min. No arterial pulsations were detectable, even at the carotid and femoral sites. Because catecholamine therapy failed to increase the heart rate, the patient was suspected to be profoundly hypothermic. After confirming core hypothermia with a rectal temperature of 25 degrees C (77 degrees F) at the initial receiving hospital, transfer to an institution with cardiac surgery facilities was initiated. During this transport and after arrival, ventricular fibrillation occurred at decreasing intervals followed by asystole, which was refractory to large doses of epinephrine. The patient was transferred to the operating room under continuous resuscitation maneuvers and cardiopulmonary bypass was instituted via the femoral vessels. After 110 min of extracorporeal circulation (ECC, flow 4.5 l/min) normothermia was achieved and the asystole reverted spontaneously to sinus rhythm. The patient's course was subsequently complicated by worsening pulmonary gas exchange with signs of pulmonary edema on X-ray films and cardiac failure, which was treated successfully with epinephrine and dopamine. No neurological deficits were detectable after consciousness had returned.(ABSTRACT TRUNCATED AT 250 WORDS)

Extracorporeal Circulation↗
PubMed1991

Comparison of severity of illness indicators in an intensive care unit.

Meaningful comparison of patient outcomes requires an assessment of the severity of illness for the patients being compared. The more severe the underlying illness, the worse the expected outcome. We studied several severity of illness indicators derived from different methodologies in a medical intensive care unit. We compared the Acute Physiologic and Chronic Health Evaluation II, the accepted benchmark indicator for intensive care units, with one complex indicator, Computerized Severity Score, and three simpler indicators, Comorbidity, McCabe-Jackson, and American Society of Anesthesiologists. We found that all correlated well with a comorbidity index. We conclude that the Acute Physiologic and Chronic Health Evaluation II, the Computerized Severity Score, and the McCabe-Jackson scoring systems appear to be comparable predictors of comorbidity in a medical intensive care unit. Selection of a severity indicator will depend on the resources available and the intended uses.

Aged↗
PubMed1990

The influence of pancuronium and vecuronium combined with balanced anaesthesia on haemodynamics and myocardial oxygen balance.

The effects of the non-depolarizing muscle relaxants pancuronium (Pancuronium) and vecuronium (Norcuron) (0.1 mg/kg) on myocardial blood flow, myocardial oxygen consumption, myocardial lactate balance, cardiovascular dynamics and electrocardiogram were studied in two groups of eight patients undergoing coronary artery bypass surgery. After induction of anaesthesia with 0.015-0.02 mg/kg flunitrazepam, isoflurane (0.5 vol%) and N2O/O2 (l/l), neuromuscular blockade was induced with pancuronium or vecuronium (0.1 mg/kg) combined with a single dose of 0.005 mg/kg fentanyl. Haemodynamic measurements were performed and the electrocardiogram was recorded before anaesthesia, in steady-state anaesthesia, after relaxation with pancuronium or vecuronium combined with fentanyl, and after intubation. The haemodynamic data consisted of heart rate, cardiac index, stroke volume index, mean arterial pressure, total peripheral resistance, pulmonary arterial pressure, pulmonary capillary wedge pressure, right atrial pressure, myocardial blood flow, coronary vascular resistance, myocardial oxygen consumption, coronary aterio-mixed venous content difference, myocardial lactate extraction and rate pressure product. In the vecuronium group, heart rate decreased significantly more (21%) than in the pancuronium group (9%). Therefore myocardial oxygen consumption (48% resp. 35%) and coronary blood flow (31% resp. 18%) decreased more in the vecuronium than in the pancuronium group. The higher metabolic demand in the pancuronium group induced a significantly lower coronary vascular resistance, because the decrease in coronary perfusion pressure was similar in both groups. None of the other haemodynamic parameters differed significantly in either patient group. We did not observe ST-segment depressions or elevations in the ECG, increases in PCWP or myocardial lactate production. Therefore extended myocardial ischaemia can be excluded in our patients who received pancuronium or vecuronium for neuromuscular blockade.

Aged↗
PubMed1990

[Hemodynamics and myocardial energy balance in coronary surgery patients during high-dose fentanyl-pancuronium anesthesia and modified neurolept-pancuronium anesthesia].

In 8 patients with coronary artery disease (CAD) classed as NYHA II or III, anesthesia was induced with high-dose fentanyl (0.05 mg/kg) and pancuronium (0.1 mg/kg). The patients were ventilated normally with the aid of a mask (O2: air 1:1, tidal volume 10 ml/kg with a rate of 10/min) for 5 min and then intubated. In 8 further patients with CAD NYHA class II or III, anesthesia was induced with 0.02 mg/kg flunitrazepam, N2O/O2 1:1 and isoflurane 0.5 vol%; they were relaxed with pancuronium (0.1 mg/kg) in combination with a bolus of 0.005 mg/kg fentanyl. These patients were also ventilated normally for 5 min and then intubated. Measurements of cardiovascular dynamics included cardiac output (CO), heart rate (HR), arterial pressure (AP), pulmonary artery pressure (PAP), pulmonary capillary wedge pressure (PCWP), right atrial pressure (RAP), myocardial blood flow (MBF), and arterial and coronary sinus oxygen and lactate contents. Cardiac index (CI), stroke volume index (SVI), total peripheral resistance (TPR), myocardial oxygen consumption (MVO2), coronary vascular resistance (CVR), coronary perfusion pressure (CPP), myocardial oxygen content difference (AVDO2cor) and myocardial lactate extraction rate (LE) were calculated from standard formulas. Measurements and an electrocardiogram were taken before anesthesia, after induction of anesthesia and after intubation. The hemodynamic parameters HR, AP, CI, CPP were relatively stable in patients anesthetized with high-dose fentanyl and pancuronium, whereas we found greater decreases in these parameters with the balanced anesthesia technique. Determinants of myocardial oxygen demand were higher in the high-dose fentanyl group; therefore, myocardial blood flow and oxygen consumption did not decrease to the same extent as in the balanced anesthesia group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗