[Focal surgery, antibiotic therapy--and then? The role of rhAPC in sepsis]

Severe sepsis and septic shock are still the leading causes of death in the surgical ICU. The only curative therapies of sepsis are still surgery as well as antibiotic therapy to cure the focus. In addition a supportive therapy (analgesia and sedation, mechanical ventilation, titrated volume substitution and positive inotropes/vasopressor support, parenteral and enteral neutron, renal replacement therapies) should be started as early as possible. A new promising approach in sepsis therapy is the application of rhAPC. The PROWESS study revealed a significantly lower 28 day mortality in patients with severe sepsis who received drotrecogin alfa (activated) compared to patients not treated with drotrecogin alfa (activated). Guidelines for the use in severe sepsis and septic shock in surgical patients (risk of bleeding, costs) are strongly recommended.

Coronary artery distensibility and compensatory vessel enlargement--a novel parameter influencing vascular remodeling?

Vascular remodeling implies the concept of compensatory vessel enlargement to preserve luminal dimensions during atheromatous plaque development. However, negative remodeling, i.e. vessel shrinkage in response to plaque accumulation has also been described. So far, the factors influencing positive or negative remodeling are uncertain. We hypothesized that vascular distensibility, a measure of vessel compliance, is related to compensatory enlargement. In 58 patients undergoing intravascular ultrasound interrogation of a de novo lesion prior to coronary intervention, the cross-sectional vessel area (VA), lumen area (LA) and plaque area (PA = VA minus LA) were measured at end diastole and end systole at the lesion site and at the proximal and distal reference segments. Positive remodeling was defined to be present when the VA at the lesion was > 1.05 times larger than that at the proximal reference (group A), negative remodeling when the VA at the lesion was < 0.95 of the reference site (group C) and in-between was considered to be intermediate (group B). Vessel compliance was measured by calculating vascular distensibility. Results showed a similar LA at the lesion site in all groups (4.18+/-2.18 vs. 4.36+/-1.19 vs. 3.74+/-1.81 mm2, NS) while VA and PA were significantly larger in group A (17.19+/-5.08 vs. 14.22+/-3.66 and 12.45+/-4.82 mm2, p = 0.005 and 13+/-4.55 vs. 9.95+/-3.58 and 8.7+/-3.83, p = 0.003, respectively). Vascular distensibility at the proximal reference segment was significantly greater in group A (3.55+/-2.67 vs. 1.25+/-1.03 and 0.85+/-0.73 mmHg(-1), p < 0.001) with a positive correlation between remodeling and distensibility (R = 0.52, p < 0.001). In a multiple regression model including clinical and lesional factors, distensibility was the only predictor of remodeling. In conclusion, these results suggest that compensatory vessel enlargement occurs to a greater degree in patients with increased coronary artery distensibility, which appears to be a predictor for positive remodeling.

[Anesthesia in extreme obesity]

BACKGROUND

Approximately 1-2% of all anesthetized patients are morbidly obese (body mass index > 35 kg/m2). The perioperative mortality is significantly elevated (up to 20%) compared with lean patients. Morbidly obese patients are at high risk for cardiopulmonary dysfunction. Difficult airway management is reported in 13-20% of obese patients. Hypoxia is often observed due to faster desaturation during induction of anesthesia. After surgery, patients are endangered by a high incidence of obstructive sleep apnea syndrome (50%), pulmonary atelectasis (5%) and acute pulmonary embolism (5-12%).

ANESTHESIA

Individualized perioperative management is required based on preoperative history and physical examination. Modern anesthetic drugs (desfluran, sevoflurane or propofol, and remifentanil, respectively) allow rapid recovery and early postoperative mobilization. Adequate monitoring, e.g. by an intraarterial blood pressure monitoring and repetitive blood gas analyses, improves patient safety prior the onset of complications.

POSTOPERATIVE MANAGEMENT

Postoperative admission on an intensive care unit of morbidly obese patients is based upon concomitant diseases and surgical requirements. The main reason for admission is an inadequate pulmonary gas exchange. This interdisciplinary approach will reduce the risk of anesthesia and avoid complications in morbidly obese patients.

Perioperative morbidity and mortality in chronic alcoholic patients

This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were Claudia Spies and Hanne Tønnesen. The presentations were (1) Relevance of alcohol misuse in surgical patients, by Hanne Tønnesen; (2) Diagnosis of alcohol abuse and alcohol dependence, by Sven Andreasson; (3) Diagnosis of acute alcohol misuse, by Anders Helander; (4) Preoperative intervention for excessive alcohol consumption, by Kate Conigrave; and (5) Prevention and treatment of perioperative complications in chronic alcoholics, by Claudia Spies.

Hirudin versus heparin for anticoagulation in continuous renal replacement therapy

OBJECTIVE

To compare the efficacy and safety of hirudin and heparin for anticoagulation during continuous renal replacement therapy (CRRT) in critically ill patients.

DESIGN

Prospective, randomized controlled pilot study.

SETTING

Single centre; interdisciplinary intensive care unit at a university hospital.

PATIENTS

Seventeen patients receiving CRRT.

INTERVENTIONS

Patients were randomly allocated to two groups. Heparin group (nine patients): continuous administration of 250 IU/h heparin; dose was adjusted in 125 IU/h steps with a targeted activated clotting time (ACT) of 180-210 s. Hirudin group (eight patients): continuous infusion of 10 micrograms/kg/h hirudin, dose was adjusted in 2 micrograms/kg/h steps with a targeted ecarin clotting time (ECT) of 80-100 s. Observation time was 96 h.

MEASUREMENTS AND MAIN RESULTS

Measured filter run patency and haemofiltration efficacy did not significantly differ between the two groups. Three bleeding complications were observed in the hirudin group, none in the heparin group (P < 0.01). At the onset of bleeding, which occurred 60 or more hours after the start of therapy, only one patient was still under continuous hirudin administration but levels were either in therapeutic range or below.

CONCLUSIONS

Hirudin can be used efficiently for anticoagulation in CRRT. Late bleeding complications may have been caused by possible hirudin accumulation, but this was not evident from hirudin plasma and ECT levels. Since bleeding complications were observed only in the presence of documented coagulation disorders, not only adequate drug monitoring but also the plasmatic and cellular coagulation status of the patient should be taken into consideration for adjusting hirudin dosage.

N-acetylcysteine increases liver blood flow and improves liver function in septic shock patients: results of a prospective, randomized, double-blind study

OBJECTIVE

In septic shock, decreased splanchnic blood flow is reported, despite adequate systemic hemodynamics. Aacetylcysteine (NAC) was found to increase hepatosplanchnic blood flow in experimental settings. In septic shock patients, NAC improved the clearance of indocyanine green and the relationship of systemic oxygen consumption to oxygen demand. We investigated the influence of NAC on liver blood flow, hepatosplanchnic oxygen transport-related variables, and liver function during early septic shock.

DESIGN

Prospective, randomized, double-blind study.

SETTING

Septic shock patients admitted to an interdisciplinary surgical intensive care unit.

PATIENTS

We examined 60 septic shock patients within 24 hrs after onset of sepsis. They were conventionally resuscitated with volume and inotropes and were in stable condition. A gastric tonometer was inserted into the stomach and a catheter into the hepatic vein. Microsomal liver function was assessed by using the plasma appearance of monoethylglycinexylidide (MEGX).

INTERVENTIONS

Subjects randomly received either a bolus of 150 mg/kg iv NAC over 15 mins and a subsequent continuous infusion of 12.5 mg/kg/hr NAC over 90 mins (n = 30) or placebo (n = 30).

MEASUREMENTS AND MAIN RESULTS

Measurements were performed before (baseline) and 60 mins after beginning the infusion (infusion). After NAC, a significant increase in absolute liver blood flow index (2.7 vs. 3.3 L/min/m2; p = .01) and cardiac index (5.0 vs. 5.7 L/min/m2; p = .02) was observed. Fractional liver blood flow index (cardiac index-related liver blood flow index) did not change. The difference between arterial and gastric mucosal carbon dioxide tension decreased (p = .05) and MEGX increased (p = .04). Liver blood flow index and MEGX correlated significantly (r(s) = .57; p < or = .01).

CONCLUSIONS

After NAC treatment, hepatosplanchnic flow and function improved and may, therefore, suggest enhanced nutritive blood flow. The increase of liver blood flow index was not caused by redistribution to the hepatosplanchnic area, but by an increase of cardiac index. Because of its correlation with liver blood flow index, MEGX may be helpful in identifying patients who benefit from NAC treatment in early septic shock.

Different dosages of dobutamine in septic shock patients: determining oxygen consumption with a metabolic monitor integrated in a ventilator

OBJECTIVE

Oxygen consumption (VO2) obtained from respiratory gases by indirect calorimetry (VO2,IC) with a metabolic monitor integrated in a ventilator were to be compared to VO2 obtained by the Fick principle (VO2,Fick) in septic patients following an increase in oxygen delivery (DO2) induced by positive inotropic support.

DESIGN

Prospective clinical study.

SETTING

University Hospital, Surgical Intensive Care Unit (ICU).

PATIENTS

Thirty patients suffering from sepsis.

INTERVENTIONS

DO2 was increased by dobutamine infusion, starting with an initial dosage of 5 microg x kg x min, increased to a maximum of 10 microg x kg x min.

MEASUREMENTS AND MAIN RESULTS

Dobutamine infusion induced a dosage-related increase in DO2 (from 577 +/- 192 to 752 +/- 202 ml x min x m2, p < 0.01), which was associated with a statistically significant increase in VO2,IC (from 173 +/- 30 to 188 +/- 28 ml x min x m2, p < 0.01) and in VO2,Fick (from 140 +/- 25 to 156 +/- 24 ml x min x m2, p < 0.01). The comparison between VO2,IC and VO2,Fick revealed differences (bias and precision--33 +/- 32 ml x min x m2).

CONCLUSIONS

With a metabolic monitor integrated in a ventilator it was possible to carry out continuous monitoring of calorimetric data under clinical conditions. In contrast to previous studies using indirect calorimetry, this study showed a moderate correlation between VO2 and DO2 in septic patients using either method. The clinical relevance of this finding requires further investigation. Different factors (e. g. injectant temperature, pulmonary VO2) produced substantial differences between VO2,IC and VO2,Fick as previously shown.

[Assessment of bone healing during callus distraction by an automatic torsional stiffness metering system]

The present article describes a newly developed device for the quantitative assessment of torsional in vivo stiffness of regenerating bone under callus distraction. Both the design and function of this device, and its use during bony consolidation are discussed. The device exhibited an accuracy of +/- 18% for stiffness under 0.1 Nm/degree, and +/- 5% stiffness above 0.1 Nm/degree. The average accuracy was +/- 14%. The data scatter for the stiffness measurement ranged between +/- 1.43% and +/- 7.68% (average: +/- 3.99%). The precision of a test machine was between +/- 0.01% and +/- 11.3% (average: +/- 3.65%). The method has the following advantages over existing methods for investigating healing: 1. no need to dismantle the external fixation for measurement; 2. preservation of the bone axis with minimal risk of misalignment during the bone healing process; 3. minimal technical requirements, with easy, noninvasive measurement; 4. no exposure to X-radiation.

Coronary artery compliance and adaptive vessel remodelling in patients with stable and unstable coronary artery disease

OBJECTIVE

To test the hypothesis that patients with unstable coronary syndromes show accentuated compensatory vessel enlargement compared with patients with stable angina, and that this may in part be related to increased coronary artery distensibility.

DESIGN AND PATIENTS

In 23 patients with unstable coronary syndromes (10 with non-Q wave myocardial infarction and 13 with unstable angina), the culprit lesion was investigated by intravascular ultrasound before intervention. The vessel cross sectional area (VA), lumen area (LA), and plaque area (VA minus LA) were measured at end diastole and end systole at the lesion site and at the proximal and distal reference segments. Similar measurements were made in 23 patients with stable angina admitted during the same period and matched for age, sex, and target vessel. Calculations were made of remodelling index (VA at lesion site / VA at reference site), distensibility index ([(delta A/A)/delta P] x 10(3), where delta A is the luminal area change in systole and diastole and delta P the difference in systolic and diastolic blood pressure measured at the tip of the guiding catheter during a cardiac cycle), and stiffness index beta ([ln(P(sys)/P(dias))]/(delta D/D), where P(sys) is systolic pressure, P(dias) is diastolic pressure, and delta D is the difference between systolic and diastolic lumen diameters). Positive remodelling was defined as when the VA at the lesion was > 1.05 times larger than at the proximal reference site, and negative remodelling when the VA at the lesion was < 0.95 of the reference site.

RESULTS

Mean (SD) LA at the lesion site was similar in both groups (4.03 (1.8) v 4.01 (1. 93) mm(2)), while plaque area was larger in the unstable group (13. 29 (4.04) v 8.34 (3.6) mm(2), p < 0.001). Remodelling index was greater in the unstable group (1.14 (0.18) v 0.83 (0.15), p < 0.001). Positive remodelling was observed in 15 patients in the unstable group (65%) but in only two (9%) in the stable group (p < 0.001). Negative remodelling occurred only in two patients with unstable symptoms (9%) but in 17 (74%) with stable symptoms. At the proximal reference segment, the difference in LA between systole and diastole was 0.99 (0.66) mm(2) in the unstable group and 0.39 (0.3) mm(2) in the stable group (p < 0.001), and the calculated coronary artery distensibility was 3.09 (2.69) and 0.94 (0.83) per mm Hg in unstable and stable patients, respectively (p < 0.001). The stiffness index beta was lower in patients with unstable angina (1.95 (0.94) v 3.1 (0.96), p < 0.001).

CONCLUSIONS

Compensatory vessel enlargement occurs to a greater degree in patients with unstable than with stable coronary syndromes, and is associated with increased coronary artery distensibility.

[Anesthesiologic aspects of chronic alcohol abuse]

The prevalence of alcoholism exceeds 20% in surgical disciplines. Chronic alcoholics are endangered by an increased postoperative morbidity and mortality. Due to an elaborated preoperative alcoholism-related diagnostic evaluation (alcoholism-related questionnaire and laboratory markers) and an adequate perioperative management (prophylactic treatment of alcohol withdrawal symptoms and symptom-orientated therapy of infections, cardiac complications and bleeding disorders), intercurrent complications may be reduced and postoperative outcome improved.

Effect of profound normovolemic hypotension and moderate hypothermia on circulating cytokines and adhesion molecules

Hypotension caused by hypovolemic, hemorrhagic shock induces disturbances in the immune system that may contribute to an increased susceptibility to sepsis. The effect of chemically induced hypotension on circulating cytokines and adhesion molecules has not been investigated yet. In 21 patients scheduled for resection of malignant choroidal melanoma of the eye the perioperative serum levels of the cytokines IL-1beta, IL-6, IL-10, TNF-alpha, and the adhesion molecules sE-Selectin and sICAM-1 were investigated. Moderate hypothermia of 32 degrees C was induced in all patients. In 14 patients profound hypotension (mean arterial blood pressure 35-40 mmHg, hypotension group) was induced by enalapril and nitroglycerin for a mean duration of 71 min. In 7 patients the tumor was not resectable, and hypotension was not induced (controls). We did not detect significant differences in serum levels of cytokines or sE-Selectin perioperatively in patients with profound hypotension compared with controls. In both groups IL-6 serum levels increased significantly and reached a maximum after rewarming (17 +/- 6 and 16 +/- 5 pg/dL, respectively, P < 0.001). IL-1beta, IL-10, and TNF-alpha did not change perioperatively in both groups. On the first postoperative day sICAM-1 serum levels were significantly increased in both groups (mean increase of 96 and 54 ng/mL, respectively, P < 0.01 and P < 0.05). We conclude from this study that profound normovolemic arterial hypotension does not seem to have effects on serum levels of circulating IL-1beta, IL-6, IL-10, TNF-alpha, and sE-Selectin. Perioperative moderate hypothermia may be the reason for the postoperative increase in sICAM-1 levels independent of the blood pressure.

Rupture of several parasagittal bridging veins without subdural bleeding

This case reports on a fatal craniocerebral trauma involving numerous ruptured cerebral bridging veins that did not bleed subdurally, despite approximately 15 hours of survival. A 15-year-old girl was severely injured as the passenger of a car that crashed sideways into a tree. She-suffered a cerebral trauma of the "diffuse injury" type and was unconscious after the accident. Her computed tomographic scan at admission showed massive brain edema, axial herniation, and marked hypodensity of the bilateral carotid flow area. Despite intensive care measures, the clinical course was characterized by central decompensation with therapy-resistant cardiocirculatory insufficiency. The autopsy revealed ruptures of numerous parasagittal bridging veins. The injured vessels were not thrombosed, and yet there was absolutely no subdural bleeding. This unusual combination of findings is assumed to be caused by an isolated collapse of cerebral circulation occurring shortly after the accident and primarily attributed to a rapid increase of intracranial pressure.

The alveolar-arterial difference in oxygen tension increases with temperature-corrected determination during moderate hypothermia

Moderate hypothermia (32-33 degrees C) occurs in anesthetic practice. However, intrapulmonary gas exchange and the effect of temperature correction of blood gases on oxygen and carbon dioxide exchange have not been investigated in these patients. We investigated alveolar-arterial difference in oxygen tension (AaDO2) and arterial to end-tidal difference in carbon dioxide (Pa-ETCO2) during rewarming of eight ASA physical status I patients from hypothermia of 32 degrees C. Anesthesia was maintained with fentanyl/propofol. AaDO2 and Pa-ETCO2 were assessed by analyzing arterial blood gases and saturated water vapor pressure, uncorrected or corrected to actual body temperature. The respiratory quotient (RQ) was measured by calorimetry. After temperature correction of blood gases and water vapor pressure, the AaDO2 was significantly higher at 33 and 32 degrees C compared with 36 degrees C (56 +/- 13 and 64 +/- 14 vs 39 +/- 10 mm Hg; P < 0.05 and P < 0.01). The deterioration of pulmonary oxygen exchange was not detected if arterial blood gases and water vapor pressure were not corrected. The RQ did not change during moderate hypothermia compared with 36 +/-C. The temperature-corrected Pa-ETCO2 was not affected by hypothermia. We conclude that AaDO2 is increased during moderate hypothermia. This is only detected when water vapor pressure and arterial blood gases are corrected to actual body temperature.

IMPLICATIONS

We investigated intrapulmonary oxygen and carbon dioxide exchange during moderate hypothermia (32 degrees C) in eight patients. If oxygen, carbon dioxide, and water vapor pressure were corrected to actual body temperature, the alveolar-arterial oxygen tension difference was increased during hypothermia. The carbon dioxide tension difference and the respiratory quotient were unaffected by hypothermia.

[Gamma-hydroxybutyrate for treatment of alcohol withdrawal syndrome in intensive care patients. A comparison between with two symptom-oriented therapeutic concepts]

Seeing as gamma-hydroxybutyrate (GHB) and benzodiazepines interact with the GABA-transmitter system, we investigated whether GHB can replace the conventional therapy, which uses benzodiazepines in the treatment of alcohol withdrawal syndrome in ICU settings.

METHODS

42 chronic alcoholics were included in this prospective and randomized study. Following the development of alcohol withdrawal syndrome, the patients were randomly allocated to the GHB or to the flunitrazepam group. In addition to this, clonidine was administered in order to treat autonomic signs of withdrawal. In cases were hallucinations occurred, haloperidol was administered.

RESULTS

There was no significant difference in the efficacy of treatment used in the duration of mechanical ventilation and intensive care unit stay between groups. The patients in the GHB-group required significantly higher dosages of haloperidol and significantly lower dosages of clonidine. 14 out of 21 patients from the GHB-group developed hypernatriaemia and 15 out of 21 developed a metabolic alkalosis.

CONCLUSIONS

Symptoms of the autonomic nervous system were more effectively prevented by GHB as evident in the lower dosage requirement of clonidine. However, GHB may not sufficiently block the hyperactivity of the dopaminergic system or may have an hallucinogenic effect itself. This may be evident from the higher dosages of haloperidol which were necessary. Due to the latter fact, the administration of GHB cannot be recommended in all patients suffering from AWS in ICU settings.

Serum cardiac troponin T as a prognostic marker in early sepsis

STUDY OBJECTIVE

Sepsis is the leading cause of death in the noncardiologic ICU. Maldistributed nutritive blood flow and altered convective and diffusive oxygen transport during sepsis can lead to organ dysfunction and multiple organ failure. One of the causes of myocardial dysfunction is thought to be myocardial ischemia in sepsis; however, conventional biochemical parameters to detect myocardial ischemia lack sensitivity and specificity. Serum cardiac troponin T (S-TnT) was reported to have higher sensitivity and specificity in diagnosing minor myocardial injury. The aim of this study was to investigate if and how often S-TnT is pathologically elevated in patients with sepsis and to evaluate whether S-TnT might be a prognostic marker in early sepsis.

DESIGN

Prospective study.

SETTING

Surgical ICU.

PATIENTS

Twenty-six patients with sepsis were included in this study within 24 h of the onset of sepsis. The patients were allocated a priori to a high S-TnT group (S-TnT > or = 0.2 microg/L) and a low S-TnT group (S-TnT<0.2 microg/L).

MEASUREMENT

Blood samples for the determination of S-TnT and conventional myocardial ischemia markers as well as for adhesion molecules were drawn. Hemodynamic measurements were performed every 4 h during the first 24 h and then once per day over 7 days. S-TnT was determined by enzyme-linked immunosorbent sandwich assay.

RESULTS

Eighteen patients had pathologically high S-TnT values. High S-TnT values were associated with an increased mortality rate (15/18 in the high S-TnT group vs 3/8 in the low S-TnT group; p=0.02). Significant differences between the two groups were found in the norepinephrine dosages at maximum values of S-TnT. Soluble intercellular adhesion molecule-1 was significantly elevated in the high S-TnT group.

CONCLUSIONS

As high S-TnT values were associated with an increased mortality rate, it seems reasonable to further evaluate S-TnT as a prognostic marker of myocardial ischemia in patients with sepsis under different therapeutic regimens.

Laryngo-pharyngeal complaints following laryngeal mask airway and endotracheal intubation

STUDY OBJECTIVE

To investigate the incidence and severity of laryngo-pharyngeal complaints following anesthesia with the use of a laryngeal mask airway (LMA) compared with endotracheal intubation in adults.

DESIGN

Prospective study with randomized patient selection.

SETTING

University medical center.

PATIENTS

202 adult ASA physical status I, II, and III patients scheduled for elective surgery of either an extremity or breast, or a transurethral resection.

INTERVENTIONS

Following intravenous induction of anesthesia, a standard LMA size #3, #4, or #5 corresponding to the patient's body weight, was inserted in 103 patients; 99 patients were intubated with a polyvinylchloride endotracheal tube [7.5 mm inner diameter (ID) in women and 8.0 mm ID in men]. Cuff pressures in the LMA group were initially reduced to a minimum pressure at which an air-tight seal between the LMA and the laryngeal inlet was provided at a positive pressure of 20 cm H2O during manual bag ventilation. Cuffs of endotracheal tubes were inflated and controlled to a volume needed to prevent gas leak at 35 cm H2O pressure.

MEASUREMENTS AND MAIN RESULTS

Cuff pressures were continuously monitored in both groups. Patients assessed their laryngo-pharyngeal complaints on a 101-point numerical rating scale on the evening after surgery and the following two days. No difference was found in the incidence and severity of sore throat on the evening following surgery or on the two following days. Dysphonia was more frequent following intubation than following LMA insertion on the day of surgery (46.8% vs. 25.3%) and on the first postoperative day (28.1% vs. 11.6%) (p < 0.05). However, the incidence of dysphonia increased with the duration of anesthesia in LMA patients but not in intubated patients. The incidence of dysphagia was significantly higher following LMA insertion compared with endotracheal intubation on the day of surgery (23.8% vs. 12.5%), and on the first postoperative day (22.3% vs. 10.4%). The severity of the individual complaints of minor laryngo-pharyngeal morbidity was comparable between groups. The type of airway management during anesthesia did not affect patient satisfaction with the anesthesia received.

CONCLUSIONS

There is a distinct pattern of laryngo-pharyngeal complaints following the use of the LMA and endotracheal intubation. With regard to minor laryngo-pharyngeal morbidity, the advantage of the LMA to endotracheal intubation is questionable.

The effects of low-dose dopamine on splanchnic blood flow and oxygen uptake in patients with septic shock

OBJECTIVE

To assess the effects of low-dose dopamine on splanchnic blood flow and splanchnic oxygen uptake in patients with septic shock.

DESIGN

Prospective, controlled trial.

SETTING

University hospital intensive care unit.

PATIENTS

11 patients with septic shock, diagnosed according the criteria of the 1992 American College of Chest Physicians/Society of Critical Care Medicine consensus conference, who required treatment with norepinephrine.

MEASUREMENTS AND MAIN RESULTS

Systemic and splanchnic hemodynamics and oxygen transport were measured before and during addition of low-dose dopamine (3 micrograms/kg per min). Low-dose dopamine and a marked effect on total body hemodynamics and oxygen transport. The fractional splanchnic flow at baseline ranged from 0.15 to 0.57. In 7 patients with a fractional splanchnic flow less than 0.30, low-dose dopamine increased splanchnic flow and splanchnic oxygen delivery and oxygen consumption. In 4 patients with a fractional splanchnic flow above 0.30, low-dose dopamine did not appear to change splanchnic blood flow.

CONCLUSION

Low-dose dopamine has a potential beneficial effect on splanchnic blood flow and oxygen consumption in patients with septic shock, provided the fractional splanchnic flow is not already high before treatment.

Patient-controlled intranasal analgesia: a method for noninvasive postoperative pain management

Recently, a new device for patient-controlled intranasal analgesia (PCINA) was described, and a pilot study demonstrated promising results with respect to efficacy and patient satisfaction. The present study compares PCINA with intravenous (IV) patient-controlled analgesia (PCA). Fifty orthopedic patients were prospectively studied over an 8-h period on the first day after surgery. The patients were randomly allocated to PCINA group (n = 25) or to an IV PCA group (n = 25). Pain intensity was evaluated at 30-min intervals using a 101-point numerical rating scale. With respect to initial pain intensity, there was no significant intergroup difference. At the 30- to 480-min measurement points pain intensity in the PCINA group (P < 0.0001) and the IV PCA group (P < 0.0001) was significantly less as compared to the initial value. There was no significant intergroup difference in pain intensity. No patient had problems using the PCINA device. The present study demonstrates, that PCINA provides relief of postoperative pain as effectively as IV PCA.

[The effect of prophylactically administered n-acetylcysteine on clinical indicators for tissue oxygenation during hyperoxic ventilation in cardiac risk patients]

Hyperoxic ventilation, used to prevent hypoxia during potential periods of hypoventilation, has been reported to paradoxically decrease whole-body oxygen consumption (VO2). Reduction in nutritive blood flow due to oxygen radical production is one possible mechanism. We investigated whether pretreatment with the sulfhydryl group donor and O2 radical scavenger N-acetylcysteine (NAC) would preserve VO2 and other clinical indicators of tissue oxygenation in cardiac risk patients.

METHODS

Thirty patients, requiring hemodynamic monitoring (radial and pulmonary artery catheters) because of cardiac risk factors, were included in this randomized investigation. All patients exhibited stable clinical conditions (hemodynamics, body temperature, hemoglobin, F1O2 < 0.5). Cardiac output was determined by thermodilution and VO2 by cardiovascular Fick. After baseline measurements, patients randomly received either 150 mg kg-1 NAC (n = 15) or placebo (n = 15) in 250 ml 5% dextrose i.v. over a period of 30 min. Measurements were repeated 30 min after starting NAC or placebo infusion, 30 min after starting hyperoxia (F1O2 = 1.0), and 30 min after resetting the original F1O2.

RESULTS

There were no significant differences between groups in any of the measurements before treatment and after the return to baseline F1O2 at the end of the study, respectively. NAC, but not placebo infusion, caused a slight but not significant increase in cardiac index (CI), left ventricular stroke work index (LVSWI) and a decrease in systemic vascular resistance. Significant differences between groups during hyperoxia were: VO2 (NAC: 108 +/- 38 ml min-1m-2 vs placebo: 79 +/- 22 ml min-1m-2; P < or = 0.05), CI (NAC: 4.6 +/- 1.0 vs placebo: 3.7 +/- 1.11 min-1m-2; P < or = 0.05) and LVSWI (NAC: 47 +/- 12 vs placebo: 38 +/- 9; P < or = 0.05). The mean decrease of VO2 was 22% in the NAC group vs 47% in the placebo group (P < or = 0.05) and the mean difference between groups in venoarterial carbon dioxide gradient (PvaCO2) was 14% (P < or = 0.05). ST segment depression ( > 0.2 mV) was significantly less marked in the NAC group (NAC: -0.02 +/- 0.17 vs placebo: -0.23 +/- 0.15; P < or = 0.05).

CONCLUSIONS

NAC helped preserve VO2, oxygen delivery, CI, LVSWI and PvaCO2 during brief hyperoxia in cardiac risk patients. Clinical signs of myocardial ischemia did not occur such as ST-depression if patients were prophylactically treated with NAC. This suggests that pretreatment with NAC could be considered to attenuate impaired tissue oxygenation and to preserve myocardial performance better in cardiac risk patients during hyperoxia.

Patient-controlled intranasal analgesia (PCINA) for the management of postoperative pain: a pilot study

STUDY OBJECTIVE

To compare patient-controlled intranasal analgesia (PCINA) for post-operative pain management with ward-provided pain therapy.

DESIGN

Randomized, prospective pilot study.

SETTING

University medical center.

PATIENTS

20 ASA status I and II orthopedic patients.

INTERVENTIONS

On the first postoperative day, 20 patients were randomized to receive either PCINA for 4 hours followed by 5 hours of ward-provided pain therapy (Group 1; n = 10) or ward-provided pain therapy for 5 hours followed by 4 hours of PCINA (Group 2; n = 10). The PCINA device used permits self-administration up to a maximum 0.025 mg dose of fentanyl every 6 minutes. Pain intensity (101-point numerical rating scale) and vital signs, as well as possible side effects, were registered at 30-minute intervals.

MEASUREMENTS AND MAIN RESULTS

Within 30 minutes after the start of PCINA, pain intensity had decreased significantly in both groups. At the 60, 150, 210, 240, 270, 390, 420, and 480 minute measuring points, there was a significant intergroup difference in pain intensity, the level being significantly lower in the PCINA period. The handling of the PCINA device presented no problem to any patient. The PCINA fentanyl requirement was 0.415 +/- 0.083 mg (Group 1) and 0.408 +/- 0.06 mg (Group 2), respectively (NS). The ward-provided pain therapy included pethidine, tramadol, metamizole, acetaminophen, codeine, and diclofenac alone or in combination. Patient satisfaction was greater with PCINA than with ward-provided pain therapy (p < 0.0005).

CONCLUSIONS

PCINA provides an adequate, noninvasive mode of postoperative pain management. The PCINA device is easy to handle and offers new perspectives in the management of postoperative pain.

Hypertonic saline in stabilized hyperdynamic sepsis

Hypertonic saline with or without colloidal solution has been successfully used for treating hemorrhagic shock in animal experiments and clinical studies. Due to its various effects at systemic, organ, and microcirculatory levels, the substance appears to be a promising candidate for improving tissue oxygenation in sepsis. We therefore investigated the hypothesis that infusion of hypertonic saline would further improve O2 delivery, O2 extraction, and O2 uptake in hyperdynamic septic shock patients already stabilized by adequate volume and catecholamine infusion. Twenty-one patients received 2-4 mL/kg body weight of hypertonic saline in hydroxyethyl starch within 15 min. This hypertonic saline infusion caused a rapid significant increase in O2 delivery by 14% but only a marginal increase in O2 consumption (7% by cardiovascular Fick [p < .05], 4% by respiratory gases [n.s.]). Hypertonic saline increased the already elevated cardiac output by 24%. The pulmonary capillary wedge pressure increased from 14 +/- 3 to 23 +/ 3 mmHg and pulmonary shunt fraction increased 15%, but arterial PO2 did not fall. Except for the increase in pulmonary capillary wedge pressure, none of the cardiovascular changes lasted longer than 60 min. Plasma sodium levels increased from 138 +/- 25 to 163 +/- 38 mmol/L and normalized within 24 h. In these hyperdynamic septic patients, hypertonic saline infusion produced a transient increase in circulation, but no evidence of a substantial increase in O2 consumption. Either there was no significant O2 debt due to the already elevated O2 delivery levels at baseline (700 mL/min/m2) or the global O2 measurements we used were not able to detect discrete regional hypoxia.

Feasibility and rate of leucocyte depletion with a single leucocyte depletion filter during massive transfusion

BACKGROUND

The study examines the feasibility and rate of leucocyte depletion with a single leucocyte depletion filter in combination with the Level 1 heat exchanging infusion/transfusion device H-500/H-25i during massive transfusions.

MATERIALS AND METHODS

LeukoGuard-6 filters (LG-6) were manufactured to fit the infusion sets of the Level 1 H-500/H-25i. This modified device was used intraoperatively in six patients with severe haemorrhage. Following determination of the white cell counts (WCC) in each buffy coat poor red cell concentrate prior to administration, WCC were then obtained from blood sampled directly distal to the filter after the first and after the last red cell concentrate was given. Leucocytes were determined in the Nageotte chamber and then calculated to determine leucocytes/250 ml (therapeutic unit). Parameters of feasibility (time for preparation of the system, the amount of transfused red cell concentrates, time interval of transfusions) were recorded.

RESULTS

The mean volume of red cell concentrates which were transfused and filtered by a single filter was 2,708 ml (S.D. +/- 797 ml) within a mean time interval of 42.5 min (S.D. +/- 26 min). With a mean WCC of 1.17 +/- 0.68 x 10(9) leucocytes/250 ml in the red cell concentrate prior to filtration the LG-6 achieved a log-3 reduction of leucocyte counts. During the transfusion the WCC distal to the filter increased on average by a factor of 3 (from 0.9 x 10(6) leucocytes/250 ml following the first blood unit to 2.7 x 10(6) leucocytes/250 ml following the last), but remained below 5 x 10(6).

CONCLUSION

Modification of the Level 1 H-500/H-25i system by incorporating the LG-6 leucocyte depletion filter provides a significant reduction of the WCC in the transfused red cell concentrates during massive transfusion. The rate of leucocyte depletion by a single leucocyte depletion filter achieves low leucocyte counts which are documented to be of therapeutical value. As the significance of leucocyte-reduced blood products for patients with haemorrhagic shock following trauma or major surgery has still to be elucidated, the presented device may be useful in the performance of future studies related to this subject.

Safe and normothermic massive transfusions by modification of an infusion warming and pressure device

A fluid-warming pressure infusion device (H-500/H25i, Level 1) was modified to meet the demands for safe, normothermic, and effective massive transfusions. By incorporating an autoventing 40 microns filter (Pall AV-SP), which was originally manufactured for use in an extracorporal circulation, the risk of accidental air embolism can be eliminated. Feasibility and efficiency of this model were tested in ten patients. The mean volume transfused and infused (packed red cells and colloids) was 6750 mL (SD +/- 2519) during a mean period of acute volume resuscitation of 55 minutes (SD +/- 30). Calculated flow rates averaged 140 mL/min, which were sufficient to stabilize all but one patient. This patient subsequently died because of uncontrollable surgical bleeding. Body temperature remained stable with a minimal mean drop of -0.3 degrees C. Supplying the Level 1 warming and pressure device with a Pall AV-SP filter allows for safe, effective, and demand-adapted massive transfusions in a large number of trauma patients at a reasonable cost.

[Cerebral ischemia during implantation of automatic defibrillators]

In order to study the influence of repetitive episodes of ventricular fibrillation (VF) during defibrillator implantation on the electrical activity of the brain, we performed an electroencephalographic (EEG) monitoring during implantation procedure in 18 patients. For defibrillation threshold testing 62 episodes of VF (1-6 episodes per patient) were induced. The mean duration of VF was 20 +/- 12 s; the mean duration of hypotension during an episode (defined as a mean arterial pressure of 50 mm Hg or less) was 33 +/- 16 s. EEG monitoring was performed using the International 10-20 System. The duration of cardiac arrest-related EEG alteration was assessed by an experienced neurologist and could be determined in 41 test-episodes; in 21 episodes analysis was not possible due to poor recordings. Ischemia-related EEG changes started 7.8 +/- 4.6 s after VF induction and lasted 64 +/- 49 s (range, 12-240). The duration of EEG alteration was significantly (p < .001) correlated with the duration of VF episodes (r = .71) and the associated hypotension (r = .82). With regard to patients the duration of ischemia related EEG changes also correlated significantly (p = .001) with the individual cumulative duration of VF (r = .85) and the associated hypotension (r = .88). In females EEG changes lasted longer than in males (p = .03); this finding, however, was only based on 2 women. Other clinical parameters, such as patient age, degree of congestive heart failure, left ventricular ejection fraction, stroke volume and cardiac index, the order of episodes within the testing sequence, and the time interval between episodes did not correlate with the duration of EEG alteration after VF induction. The duration of ischemia-related EEG alteration during VF episodes depends on the duration of cardiac arrest. In females EEG changes tended to last longer than in males, however, this finding has to be confirmed. An association with other clinical parameters has not been observed. Limitation of VF duration appears to be the most important factor to avoid prolonged cerebral ischemia.

Self-administered intranasal meperidine for postoperative pain management

Recent studies have demonstrated that intranasal is comparable to intravenous opioid titration in its pain-relieving effect. In these studies, however, the intranasal opioid titration was performed by the investigator, and the treatment period was two hours or less. The purpose of this randomized, prospective study was to investigate whether intranasal opioid administration by the patients themselves for a prolonged postoperative period may be regarded as a therapeutic alternative for postoperative pain management. Forty-four orthopaedic patients were studied over a 12-hr period on the first day after surgery. Twenty-two had free access to intranasal meperidine (nasal group) and were allowed to administer six intranasal puffs (27 mg per dose). The next self-administration was only permitted after a delay of at least ten minutes. Another 22 patients received intermittent subcutaneous meperidine injections (25 or 50 mg) on request (sc group). Pain intensity was recorded at 30-min intervals with the aid of the 101-point numerical rating scale. The pain score was lower in the nasal than in the sc group at the 30, 150 to 330, 420 to 480 and 540 to 600 min measuring points (P = < 0.05). The meperidine requirement was 112.9 +/- 81.3 mg in the nasal and 103.4 +/- 41.5 mg in the sc group (NS). Two patients in each group complained of nausea and vomiting. Thirteen of the 21 nasal and nine of the 15 sc patients who completed the final questionnaire rated the pain management as excellent or good (NS).(ABSTRACT TRUNCATED AT 250 WORDS)

[The relevance of CDT (carbohydrate-deficient transferrin). Preoperative diagnosis of chronic alcohol abuse in intensive care patients following elective tumor resection]

The increase of alcoholism-related problems is associated with vital postoperative clinical complications in chronic alcohol abusers. In particular, the alcohol withdrawal syndrome (AWS) may provoke potentially life-threatening complications in alcohol-dependent patients. Hence, a precise diagnosis of alcohol dependence is mandatory preoperatively, requiring an extensive case history using alcoholism-associated questionnaires. Additional new biological markers for detecting alcoholism could improve the accuracy of preoperative diagnosis. Carbohydrate-deficient transferrin (CDT) reflects increased alcohol consumption. The aim of our interdisciplinary study was to investigate whether the validity of the preoperative diagnosis of chronic alcohol abuse might be improved by measuring CDT. METHODS. A total of 45 patients from the departments of Otorhinolaryngology, Maxillofacial Surgery, and Abdominal and Thoracic Surgery were included in our prospective clinical study. Patients underwent resection of malignant oral, pharyngeal, laryngeal, or oesophageal tumours and were transferred to the intensive care unit for postoperative management. Routine preoperative history, examinations, and laboratory tests including GGT, MCV, ASAT, and ALAT, were supplemented by a specific alcohol-related questionnaire and CDT measurement. The patients were categorised in four groups based on history and the questionnaire: continuously abstinent subjects; sober subjects for at least 7 days; chronic abusers; and dependent subjects. CDT was separated by isocratic anion exchange chromatography and quantified by turbidimetric determination. Statistical analysis was performed by the Kruskal-Wallis test. RESULTS. Preoperatively, 21 patients were at major risk for alcoholism-related complications: 12 were chronic abusers and 9 were diagnosed as dependent. CDT was significantly increased in both groups, and was pathologically elevated in 16 of the 21 patients. Sampling occurred significantly long after the last alcohol intake in the 5 patients with normal CDT values (median: 6.0 days; range: 2-12 days) compared with the 16 with pathologically elevated CDT levels (median: 1.0 day; range: 0-4 days; P = 0.002). The sensitivity of CDT elevation was 16 out of 24 (76%), the specificity 16 out of 16 (100%). Sixteen patients had no previous history of alcohol consumption (sober for at least 7 days) and 8 were definitely abstinent. Both of these groups had normal CDT values. CONCLUSIONS. CDT was a sensitive and specific marker for chronic alcohol consumption in our patient population. Since CDT is a state marker, repeated determinations might be useful to estimate a patient's drinking habits. The combination of CDT and an alcohol-related questionnaire was reliable for detecting alcohol-dependent patients preoperatively.

The relationship between mixed venous and hepatic venous O2 saturation in patients with septic shock

It was the purpose of this study to measure the relationship between hepatic venous O2 saturation (ShvO2) and mixed venous O2 saturation (SvO2) in septic patients (n = 21) following treatment with various catecholamines (epinephrine, norepinephrine, dopamine, dopexamine). At baseline mean SvO2 was 74 +/- 5% while mean ShvO2 was 59 +/- 12%. Alpha-mimetic substances such as epinephrine and norepinephrine reduced ShvO2 and increased the difference between SvO2 and ShvO2.Beta2-mimetic and dopaminergic substances (dopexamine, dopamine) did not change the difference between SvO2 and ShvO2. These results show that SvO2 does not necessarily reflect all changes of ShvO2. Monitoring ShvO2 may be helpful in managing septic shock by adding information on adequacy of O2 supply/consumption ratio in the crucial splanchnic region.

The relevance of measuring O2 supply and O2 consumption for assessment of regional tissue oxygenation

Septic shock and ARDS are associated with disturbed tissue oxygenation. It has been suggested to increase O2 supply (DO2) above the normal level (> 600 ml/min/m2) to compensate for the tissue hypoxia. The lack of a rise in O2 consumption (VO2) after increases of DO2 has been presumed to indicate adequate tissue oxygenation (negative O2 flux test). We were interested in whether a negative O2 flux test precludes an improvement of regional tissue oxygenation. The pH value of the gastric mucosa (pHi) is considered to be a sensitive marker for hypoxia in the splanchnic region. We measured pHi as well as DO2 and VO2 in 10 patients with hyperdynamic septic shock to assess the effect of volume substitution on tissue oxygenation. The initial therapeutic approach (volume substitution and catecholamines) led to a DO2 of 717 +/- 187 ml/min/m2. However, all patients had pHi values < 7.35 indicating regional tissue hypoxia. An additional increase of DO2 by colloidal volume substitution caused a significant rise of pHi from 7.20 +/- 0.05 to 7.25 +/- 0.05 but did not change VO2. We conclude that a negative O2 flux test does not rule out regional tissue hypoxia, and second, an increase in DO2 may improve tissue oxygenation without measurable changes in VO2. Furthermore, adequate volume substitution is an important step in the treatment of septic shock to increase total body blood flow and more specifically regional blood flow.

Fatal intoxication involving etryptamine

A case of fatal intoxication due to the ingestion of Etryptamine (ethyltryptamine) is reported. Toxicological findings included the following tissue distribution: blood (heart) 5.6 mg/L; urine 80.4 mg/L; vitreous 2.4 mg/L; bile 22.0 mg/L; stomach contents 52.9 mg, brain 16.2 mg/g; liver 18.3 mg/g and kidney 24.0 mg/g. Anatomic pathology showed pulmonary edema and generalized visceral congestion with some epicardial petechiae.

[O2 supply, O2 consumption and the pH value of the gastric mucosa. Indicators of tissue oxygenation]

The lack of a rise in global O2 consumption (VO2) after increased O2 supply (DO2) (negative O2-flux test) is an indication of adequate tissue oxygenation. We were interested in whether a negative O2-flux test precludes an improvement in regional tissue oxygenation. The pH of the gastric mucosa (pHi) is considered a sensitive marker for tissue hypoxia. Method. The study was approved by the ethics committee of our hospital. In 12 intensive-care patients with septic shock, gastric pHi was determined (Trip'TGS catheter, Tonometrics) in addition to measuring O2-transport-related parameters via invasive haemodynamic monitoring. Following the initial measurement, a further increase in the O2 supply via volume substitution was attempted in all already hyperdynamic patients with DO2 in the upper-normal range. Results. Volume substitution with 1.246 +/- 594 ml colloid resulted in an increase in pulmonary capillary wedge pressure from 14 +/- 2 mm Hg to 17 +/- 1 mm Hg (P < 0.01). All patients had an increase in DO2 from 755 +/- 192 ml/min.m2 to 846 +/- 236 ml/min.m2 (P < 0.05). There was no significant change in VO2, at 153 +/- 28 ml/min.m2 before and 156 +/- 35 ml/min.m2 after volume administration. However, pHi increased from 7.19 +/- 0.08 to 7.24 +/- 0.08 (P < 0.01). DISCUSSION AND CONCLUSION. The low pHi at the time of the initial measurement shows that regional tissue hypoxia may be present even in patients with an above-normal O2 supply > 600 ml/min.m2. Apparently, the lack of rise in global O2 consumption after increased O2 supply does not exclude a regional improvement in tissue oxygenation. The less invasive pHi measurement is an additional useful monitoring procedure for the optimisation of regional tissue oxygenation in critically ill patients.

[Hepatic venous and mixed venous O2 saturation during catecholamine therapy in patients with septic shock]

Mixed venous O2-saturation (SvO2) reflects the ratio of global O2 supply to O2 consumption. However, in septic shock, there may be alterations in the ratio of regional O2 supply to O2 consumption, particularly in the splanchnic region. The aim of the study was therefore to investigate the relation between SvO2 and hepaticovenous O2-saturation (ShvO2) in septic shock with different catecholamine regimens. METHOD. Following approval of the ethics commission at our hospital, SvO2 and ShvO2 were measured simultaneously in 29 patients (7.5-F pulmonary arterial catheter). RESULTS. SvO2 and ShvO2 showed a considerable inter-individual difference with values between 1.3 and 36.9% and a mean of 14.7 +/- 9.3%. Alterations of ShvO2 were only tendentially reflected in alterations of the SvO2. Under different catecholamines SvO2 and ShvO2 showed the same changes but varying in extent (Table 1; Fig. 2). After switching the catecholamine therapy from dobutamine to epinephrine, SvO2 decreased only from 76.7 +/- 3.6 to 76.1 +/- 2.3 but ShvO2 from 61.4 +/- 8.1 to 54.2 +/- 10.3%. When the therapy was switched from dobutamine to norepinephrine, SvO2 decreased from 74.8 +/- 4.9% to 68.5 +/- 4.8%, ShvO2 decreased from 61.9 +/- 12.9% to 49.2 +/- 12.8%. When dopamine was added to norepinephrine, SvO2 increased from 68.6 +/- 4.3% to 73.6 +/- 4.4%, ShvO2 increased from 52.6 +/- 12.7% to 63.7 +/- 9.8%. When dopexamine was added to dobutamine, SvO2 increased from 74.6 +/- 4.5% to 76.9 +/- 2.5%, while ShvO2 increased from 57.6 +/- 11.5% to 58.8 +/- 13.4%. DISCUSSION AND CONCLUSION. The results presented show that SvO2 does not provide sufficient information about the venous O2 saturation of the splanchnic region. The intraindividually variable differences between SvO2 and ShvO2 during therapeutic interventions demonstrate that a selective alteration of blood supply to or O2 consumption of the splanchnic region has taken place, which is insufficiently reflected by the SvO2.

[The accuracy of 4 different oximeters for continuous monitoring of mixed venous oxygen saturation during abdominal aortic surgery]

Several systems for mixed-venous oximetry are now available. There are one three-wave-length system (Abbott) and three two-wave-length systems with (Spectramed) and without automatic correction for hemoglobin or hematocrit (Edwards). The purpose of this prospective randomized study was to compare the different systems and to examine the accuracy of continuous mixed-venous oximetry during abdominal aortic surgery. Eighty patients had a radial artery cannula and one of the following fiberoptic pulmonary artery catheters inserted before induction of anesthesia: Swan-Ganz oximetry TD catheter (Edwards), Swan-Ganz flow-directed oximetry thermodilution paceport catheter (Baxter, Edwards Division), SpectraCath STP (Spectramed), and Opticath (Abbott). Mixed-venous O2 saturation was monitored by oximetry computers: SAT-1 (Edwards), SAT-2 (Baxter, Edwards Division), Hemopro2 (Spectramed), and Oximetrix 3 (Abbott). As a method of reference, mixed-venous blood samples were drawn and immediately analyzed by an OSM3-Hemoximeter. Data sets were obtained at eight predetermined times. Hemoglobin was kept constant at +/- 1 g.dl-1. Continuous oximetry in comparison to in-vitro measurements yielded a correlation coefficient of r = 0.873 (P less than 0.0001) and a value of bias and precision (b +/- p) of -0.9 +/- 2.6% for the SAT-1, r = 0.815 (P less than or equal to 0.0001) and b +/- p = -2.2 +/- 2.5% for the SAT-2, r = 0.901 (P less than or equal to 0.0001) and b +/- p = 0.35 +/- 2.5% for the Hemopro2, and r = 0.920 (P less than or equal to 0.0001) and b +/- p = 0.1 +/- 1.8% for the Oximetrix 3, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

[A comparison of enflurane and propofol in thoracic surgery]

Comparisons between propofol and inhalational anesthetics for maintenance of anesthesia are limited. The purpose of our prospective study was to examine differences between enflurane and propofol during pulmonary resections with one-lung ventilation (1LV). METHOD. 28 patients, ASA risk group II-III, gave written informed consent for inclusion in this institutionally approved study. The patients were randomly allocated to one of the following groups: A: propofol 10 mg kg-1 h-1, B: 1 MAC enflurane, for maintenance of anesthesia. In both groups analgesia was achieved by fentanyl and muscle relaxation, by pancuronium. Ventilation via a double-lumen tube was controlled (FiO2 = 1.0, PaCO2 35-40 mmHg). Measurements, including hemodynamics and arterial and mixed venous blood gases, were obtained before induction (I), during two-lung ventilation (2LV) 15 min after induction in the supine position (II) and 20 min after surgical opening of the chest in the lateral decubitus position (III), 20 min after starting 1LV (IV), and after extubation (V). RESULTS. No significant differences between the two groups were found before induction (I), during 2LV (II, III), or after extubation (V). The only significant differences between the two groups were observed during 1LV (IV): the shunt fraction was 33.9 +/- 2.5% in A and 38.5 +/- 2.6% in B (P less than or equal to 0.05). Hypoxic pulmonary vasoconstriction was not inhibited in A, but was inhibited by 21.5% in group B during 1LV. Since no case of hypoxemia occurred in group A during 1LV (range of PaO2: 75.2-417.0 mmHg), but four patients developed hypoxemia in group B (Range of PaO2: 46.6-431.0 mmHg), regimen A might be of value in high-risk patients during thoracic surgery when 1LV is planned.

The aged pineal gland: reduction in pinealocyte number and adrenergic innervation in male rats

Previous biochemical and physiological studies point to an age-related loss of pineal function. Morphological studies revealed increased connective tissue and glial cell numbers in the gland. In the present study we investigated whether the number of parenchymal cells and the incidence of sympathetic fibers in the rat pineal gland is altered with advanced age. The comparison of pineal histology of young adult (2-3 months old) and aged animals (22-26 months old) showed that pinealocyte number in old animals is decreased by 18%. In addition, sympathetic innervation of the gland as revealed by glyoxylic acid fluorescence is drastically reduced in these animals. It is concluded that the age-related decline in pineal metabolism may be due to both decreased parenchymal cell number and reduced sympathetic innervation.