Biomedical subjects

B Schwarz

Publications and source records attributed to B Schwarz.

At least 19 recordsLinked to original sources

PubMed2003

Cardiopulmonary resuscitation after near drowning and hypothermia: restoration of spontaneous circulation after vasopressin.

Recent animal data have challenged the common clinical practice to avoid vasopressor drugs during hypothermic cardiopulmonary resuscitation (CPR) when core temperature is below 30 degrees C. In this report, we describe the case of a 19-year-old-female patient with prolonged, hypothermic, out-of-hospital cardiopulmonary arrest after near drowning (core temperature, 27 degrees C) in whom cardiocirculatory arrest persisted despite 2 mg of intravenous epinephrine; but, immediate return of spontaneous circulation occurred after a single dose (40 IU) of intravenous vasopressin. The patient was subsequently admitted to a hospital with stable haemodynamics, and was successfully rewarmed with convective rewarming, but died of multiorgan failure 15 h later. To the best of our knowledge, this is the first report about the use of vasopressin during hypothermic CPR in humans. This case report adds to the growing evidence that vasopressors may be useful to restore spontaneous circulation in hypothermic cardiac arrest patients prior to rewarming, thus avoiding prolonged mechanical CPR efforts, or usage of extracorporeal circulation. It may also support previous experience that the combination of both epinephrine and vasopressin may be necessary to achieve the vasopressor response needed for restoration of spontaneous circulation, especially after asphyxial cardiac arrest or during prolonged CPR efforts.

Adult↗

PubMed2003

Neither vasopressin nor amiodarone improve CPR outcome in an animal model of hypothermic cardiac arrest.

BACKGROUND: Aim of this experimental animal study was to investigate the influence of vasopressin and amiodarone on cardiopulmonary resuscitation (CPR) outcome in a pig model of hypothermic cardiac arrest. METHODS: After surface cooling to a core temperature of 26 degrees C, ventricular fibrillation was induced in 14 12-16-week-old domestic pigs. After 15 min of untreated cardiac arrest, a manual closed chest CPR was started and pigs were randomly assigned to two treatment groups: Group 1 pigs (n = 7) received vasopressin 0.4 U kg-1 as initial drug therapy, followed by a combination vasopressin (0.4 U kg-1) and amiodarone (4 mg kg-1) as subsequent drug therapy. Subsequent drug therapy was administered in animals without permanent restoration of spontaneous circulation after a first series of electrical countershocks 10 min after drug administration. Group 2 pigs (n = 7) received saline placebo as initial drug therapy and saline placebo and amiodarone (4 mg kg-1) as subsequent drug therapy. RESULTS: Vasopressin significantly increased coronary perfusion pressure and defibrillation success (successful defibrillation in five of seven Group 1 vs. none of seven Group 2 pigs, P = 0.02). Due to refibrillation within 30-150 s, the 60-min survival rate was not improved by vasopressin. Subsequent drug therapy with amiodarone had no further effect on defibrillation success or the refibrillation rate. CONCLUSIONS: Data from this experimental animal model suggest that vasopressin and amiodarone may not be beneficial for treatment of ventricular fibrillation associated with severe hypothermia when concomitant measures at core rewarming are not applied.

Amiodarone↗

PubMed2002

Quality of life 2-10 years after combined treatment for advanced oral and oropharyngeal cancer.

This study reports the findings of an evaluation of Quality of Life (QOL) in long-term survivors of advanced oral and oropharyngeal cancer treated with preoperative chemoradiotherapy followed by surgery (combined treatment=multimodal therapy). All patients had T2-T4 tumours and all received locoregional radical resection and simultaneous microvascular reconstruction. From 1990 to 1998, 181 patients have been treated at the University Hospital of Cranio-Maxillofacial and Oral Surgery in Vienna. 100 (55%) of these patients were alive and free of disease in 2000. Sixty-seven of them completed the EORTC questionnaires QLQ 30 and QLQ H&N 35. We found these questionnaires to be very good tools for determining QOL, which constitutes part of the therapeutic success. Patients tended to report good to very good QOL. A comparison between groups according to clinical data was conducted as well as a group comparison of patients who claimed especially high or low QOL in the questionnaires. It was found that combined treatment not only offers the best chances for survival, but also allows a subsequent QOL, that is comparable to other forms of therapy.

Antibiotics, Antineoplastic↗

PubMed2002

Adverse tissue reactions to wear particles from Co-alloy articulations, increased by alumina-blasting particle contamination from cementless Ti-based total hip implants. A report of seven revisions with early failure.

We revised seven alumina-blasted cementless hip prostheses (Ti-alloy stems, cp Ti threaded sockets) with low- or high-carbon Co-alloy bearings at a mean of 20.1 months after implantation because of pain and loosening. Histological examination of the retrieved periprosthetic tissues from two cases in which the implant was stable and three in which the socket was loose showed macrophages with basophilic granules containing metal and alumina wear particles and lymph-cell infiltrates. In one of the two cases of stem loosening the thickened neocapsule also contained definite lymphatic follicles and gross lymphocyte/plasma-cell infiltrates. Spectrometric determination of the concentration of elements in periprosthetic tissues from six cases was compared with that of joint capsules from five control patients undergoing primary hip surgery. In the revisions the mean concentration of implant-relevant elements was 693.85 microg/g dry tissue. In addition to Cr (15.2%), Co (4.3%), and Ti (10.3%), Al was predominant (68.1%) and all concentrations were significantly higher (p < 0.001) than those in the control tissues. The annual rates of linear wear were calculated for six implants. The mean value was 11.1 microm (heads 6.25 microm, inserts 4.82 microm). SEM/EDXA showed numerous fine scratches and deep furrows containing alumina particles in loosened sockets, and stems showed contamination with adhering or impacted alumina particles of between 2 and 50 microm in size.

Aged↗

PubMed2002

The axillocoronary bypass. Blood flow and short-term graft histology in a porcine model.

BACKGROUND: Bypass grafts arising from the axillary artery may be indicated for complications during minimally invasive direct coronary artery bypass grafting, for redo operations and for management of a severely atherosclerotic ascending aorta. As basic data research on this technique is scanty, we investigated intraoperative function and postoperative morphology of axillocoronary bypass grafts in a porcine model. METHODS: Thirteen German domestic pigs received an axillocoronary vein graft (Group I, n=7) or an aortocoronary vein graft (Group II, n=6) to the left anterior descending artery. In Group I the proximal anastomosis was performed to the left axillary artery, and after partial rib resection the graft was brought transpleurally to the target vessel. In both groups the coronary anastomosis was carried out on the beating heart without cardiopulmonary bypass. Graft flow was measured using transit time ultrasonic flow probes. RESULTS: Intraoperatively all grafts showed a typical diastolic flow profile. Stable graft flow was lower in axillocoronary bypass grafts: 47 (30-60 mL/min) in Group I and 65 (35-126 mL/min) in Group II (p=0.005). Flow given as percentage of cardiac output, however, did not differ between the two grafts: 0.9 (0.6-1.2%) in Group I and 1.2 (0.8-2.4%) in Group II (p=NS). At day 4 after surgery there was no clear histologic predilection site for microtrauma and early degenerative changes in the axillocoronary graft. CONCLUSIONS: Axillocoronary bypass flow compares well with flow in the aortocoronary graft. Microtrauma after implantation and early degenerative changes in the axillocoronary vein bypass are not particularly impacted by the thoracic entry site.

Anastomosis, Surgical↗

PubMed2001

[Prevalence of sleep disorders in school children between 11 and 15 years of age].

UNLABELLED: Little is known about sleep disorders in children and adolescents that might affect physical and emotional well-being. Depending on age and size of the cohort group, and differences in questionnaires, prevalence varies between 1-43% in international studies. We examined the prevalence of symptoms characteristic of sleep disorders in school aged children with a questionnaire which allows indication of symptoms by the children themselves. METHODS: An anonymous questionnaire, based on the German Dresden questionnaire, with 22 questions concerning the main symptoms of obstructive sleep apnea syndrome (OSAS), general symptoms of para- and insomnia as well as sociodemographic data, was developed. 332 pupils (age: 11-15 y, mean: 12.75 y; median: 12 y; 56% female, 44% male) in 2 high schools in Vienna were investigated. RESULTS: 28% (n = 93/332) of the examined group reported snoring (the main symptom of OSAS) and/or insomnia (night waking almost every night) or parasomnia (nightmares, night terrors or sleepwalking almost every night). 15% (n = 14/93) of this subgroup reported snoring and para- or insomnia coincidentally. Girls were affected more frequently than boys by nocturnal awakening (79% vs. 56%, p < 0.001) and nightmares (64% vs. 52%, p < 0.01). The snoring group (21% (71/332) of all examined children) was affected more frequently by mouth dryness (16% vs. 4%, p < 0.001), pallor (7% vs. 3%, p < 0.01), night sweats (6% vs. 1%, p < 0.05) and from the following sleep disorders: nightmares (10% vs. 2%, p < 0.01), night terrors (4% vs. 1.5%, p < 0.001), sleepwalking (1.4% vs. 1%, p < 0.05) and nocturnal awakening (16% vs. 5%, p < 0.01). DISCUSSION: Almost every fifth child reports about at least one main symptom characteristic of OSAS. The statistically significant relation between symptoms of OSAS and non-organic sleep disorders shows the necessity of interdisciplinary focusing on sleep disorders. Further epidemiological studies need to be carried out in order to clarify the role of sleep anamnesis in the diagnosis and management of sleep disorders during childhood.

Adolescent↗

PubMed2001

Effects of norepinephrine and phenylephrine on intestinal oxygen supply and mucosal tissue oxygen tension.

OBJECTIVES: To investigate effects of intravenous norepinephrine (NE) and phenylephrine (PE) on intestinal oxygen supply in an autoperfused, innervated jejunal segment. DESIGN AND SETTING: Prospective, randomized animal study in an animal research laboratory. MATERIALS AND METHODS: In 24 anesthetized and normoventilated pigs a segment of the jejunal mucosa was exposed by midline laparotomy and antimesenteric incision. Mucosal oxygen tension (PO2muc; Clark-type surface oxygen electrodes), microvascular hemoglobin oxygen saturation (HbO2, tissue reflectance spectrophotometry), and microvascular blood flow (perfusion units, PU; laser Doppler velocimetry), systemic hemodynamics, mesenteric-venous acid base and blood gas variables, and systemic acid base and blood gas variables were recorded after a resting period and at 20-min intervals during infusion of NE (0.01, 0.05, 0.1, 0.5, 1, 2 micrograms x kg-1 x min-1; n = 8) or PE (0.1, 0.5, 1, 2, 5, 10 micrograms x kg-1 x min-1; n = 8) and in controls (n = 8) without treatment. RESULTS: NE infusion led to significant tachycardia, an increase in cardiac output, and systemic oxygen delivery and consumption while PE progressively increased mean arterial pressure with only small effects on systemic blood flow. NE or PE infusion did not affect mesenteric venous oxygen tension (baseline: PE 53 +/- 5, NE, 52 +/- 4.2 mmHg), mesenteric oxygen extraction ratio (baseline: PE 0.29 +/- 0.08, NE 0.3 +/- 0.06), jejunal microvascular blood flow (baseline: PE 254 +/- 127, NE 282 +/- 72 PU), PO2muc (baseline: PE 31 +/- 9.1, NE 33 +/- 11 mmHg), and HbO2 (baseline: PE 52 +/- 9.6%, NE 58 +/- 11.6%). CONCLUSION: Despite major differences in systemic hemodynamics jejunal tissue oxygen supply is not affected by progressively increasing intravenous infusion of norepinephrine and phenylephrine.

Animals↗

PubMed2001

Effects of epinephrine in a pig model of hypothermic cardiac arrest and closed-chest cardiopulmonary resuscitation combined with active rewarming.

OBJECTIVE: The aim of the current study was to assess the effects of epinephrine in a pig model of hypothermic cardiac arrest followed by closed-chest cardiopulmonary resuscitation combined with active rewarming, simulating the clinical management of an arrested hypothermic patient in a hospital without cardiopulmonary bypass facilities. DESIGN: Prospective, randomized animal study. SETTING: University research laboratory. SUBJECTS: Twelve 12- to 16-week-old domestic pigs. INTERVENTIONS: Pigs were surface cooled to a body core temperature of 28 degrees C. After 4 min of untreated cardiac arrest, manual closed-chest CPR and thoracic lavage with 40 degrees C warmed fluid were started. After 3 min of external chest compression animals were randomly assigned to receive epinephrine (45, 45 and 200 microg/kg) or saline placebo in 5-min intervals. MEASUREMENTS AND MAIN RESULTS: Coronary perfusion pressure was about 15 mmHg in placebo group pigs. Coronary perfusion pressure was significantly higher after epinephrine, but restoration of spontaneous circulation was not more frequent (one of six epinephrine versus three of six saline placebo pigs, P=0.34). After 45 microg/kg epinephrine the arterial PO(2) was significantly lower when compared to the saline placebo. The third 200 microg/kg epinephrine dose resulted in a significantly enhanced mixed venous hypercarbic acidosis. CONCLUSIONS: After a short 4-min period of hypothermic cardiac arrest, epinephrine may not be necessary to maintain coronary perfusion pressure around the threshold usually correlating with successful defibrillation, even during prolonged closed-chest CPR combined with active rewarming. The enhanced mixed venous hypercarbic acidosis in epinephrine-treated animals may support the argument against repeated or high dose epinephrine administration during hypothermic CPR.

Analysis of Variance↗

PubMed2001

Orthotopic liver transplantation in a patient with severe portopulmonary hypertension.

Liver transplantation in patients with severe portopulmonary hypertension (PPH) has been associated with mortality rates in the range of 70% to 80%. Preoperative long-term epoprostenol therapy reverses pulmonary hypertension and may be a valuable possibility to reduce mortality in patients with severe PPH undergoing orthotopic liver transplantation. We want to report a patient with severe PPH, who was treated with intravenous epoprostenol for an 8-month period, after which pulmonary vascular resistance had decreased from 12 to 3 Wood units. Nevertheless, the patient developed intractable perioperative right heart failure necessitating transient mechanical circulatory support. The patient was weaned from mechanical circulatory support, but died from another episode of acute right heart failure after 28 days. Complicated liver transplantation associated with major cardiovascular stress is obviously not tolerated in patients with severe portopulmonary hypertension even after preoperative long-term epoprostenol therapy.

Adult↗

PubMed2001

[Treatment of coronary risk factors by general practitioners in Austria].

Aim of the study was to investigate attitudes and practice of coronary prevention in offices of general practitioners and internists. 67 Austrian physicians took part in a mail survey focussing on hyperlipidemia. 96.6% of participating physicians recommend dietary intervention at least at total cholesterol levels of 250 mg/dl, 98.0% prescribe lipid-lowering drugs at least at total cholesterol levels of 300 mg/dl. At corresponding levels of total/HDL cholesterol ratios and especially at corresponding levels of LDL-cholesterol the proportion was lower. On average 37.9% of physicians spend up to 5 minutes for patients with hyperlipidemia, 10.3% spend more than 15 minutes. The time frame is similar in overweight patients, and bigger in patients with hypertension and diabetes. Dietary therapy is estimated similarly successful in patients with hyperlipidemia and overweight, but estimated more successful in patients with hypertension and diabetes. Drug therapy of hyperlipidemia is estimated more successful than in overweight and diabetes, and worse compared with hypertension. Main measures for improving prevention are more time and specific postgraduate education. The majority of physicians feel that within the last five years quality has improved both in the outpatient and the inpatient care.

Attitude of Health Personnel↗

PubMed2001

Liver transplantation without venovenous bypass: morbidity and mortality in patients with greater than 50% reduction in cardiac output after vena cava clamping.

OBJECTIVE: To investigate whether a decrease in cardiac output of >or=50% after vena cava clamping is associated with an increase in perioperative morbidity or mortality in patients undergoing orthotopic liver transplantation without venovenous bypass. DESIGN: Retrospective, clinical study. PARTICIPANTS: Patients undergoing elective orthotopic liver transplantation without venovenous bypass (n = 172). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: In 82 patients (group 1), the decrease in cardiac output after vena cava clamping was >or=50%; in 90 patients (group 2), the decrease was <50%. Hemodynamics during surgery and perioperative morbidity and mortality were compared between group 1 and group 2 patients. Mean arterial pressure during the anhepatic phase was not significantly different between groups, but cardiac output and mixed venous oxygen saturation were significantly lower in group 1 patients. Perioperative mortality, need for postoperative renal replacement therapy, postoperative serum creatinine levels, and graft function were not different between groups. CONCLUSION: A >50% reduction in cardiac output after vena cava clamping is not associated with an increase in perioperative morbidity and mortality when compared with patients with a less pronounced reduction in cardiac output. These results question the common practice of basing the indication for venovenous bypass during the anhepatic phase on a reduction in cardiac output of >50% after a trial of vena cava clamping.

Cardiac Output↗

PubMed2001

Effects of epinephrine on intestinal oxygen supply and mucosal tissue oxygen tension in pigs.

OBJECTIVE: To study the effects of increasing dosages of epinephrine given intravenously on intestinal oxygen supply and, in particular, mucosal tissue oxygen tension in an autoperfused, innervated jejunal segment. DESIGN: Prospective, randomized experimental study. SETTING: Animal research laboratory. SUBJECTS: Domestic pigs. INTERVENTIONS: Sixteen pigs were anesthetized, paralyzed, and normoventilated. A small segment of the jejunal mucosa was exposed by midline laparotomy and antimesenteric incision. Mucosal oxygen tension was measured by using Clark-type surface oxygen electrodes. Microvascular hemoglobin oxygen saturation and microvascular blood flow (perfusion units) were determined by tissue reflectance spectrophotometry and laser-Doppler velocimetry. Systemic hemodynamics, mesenteric-venous acid-base and blood gas variables, and systemic acid-base and blood gas variables were recorded. Measurements were performed after a resting period and at 20-min intervals during infusion of increasing dosages of epinephrine (n = 8; 0.01, 0.05, 0.1, 0.5, 1, and 2 microg x kg(-1) x min(-1)) or without treatment (n = 8). In addition, arterial and mesenteric-venous lactate concentrations were measured at baseline and at 60 and 120 mins. MEASUREMENTS AND MAIN RESULTS: Epinephrine infusion led to significant tachycardia; an increase in cardiac output, systemic oxygen delivery, and oxygen consumption; and development of lactic acidosis. Epinephrine significantly increased jejunal microvascular blood flow (baseline, 267 +/- 39 perfusion units; maximum value, 443 +/- 35 perfusion units) and mucosal oxygen tension (baseline, 36 +/- 2.0 torr [4.79 +/- 0.27 kPa]; maximum value, 48 +/- 2.8 torr [6.39 +/- 0.37 kPa]) and increased hemoglobin oxygen saturation above baseline. Epinephrine increased mesenteric venous lactate concentration (baseline, 2.9 +/- 0.6 mmol x L(-1); maximum value, 5.5 +/- 0.2 mmol x L(-1)) without development of an arterial-mesenteric venous lactate concentration gradient. CONCLUSIONS: Epinephrine increased jejunal microvascular blood flow and mucosal tissue oxygen supply at moderate to high dosages. Lactic acidosis that develops during infusion of increasing dosages of epinephrine is not related to development of gastrointestinal hypoxia.

Acidosis, Lactic↗

PubMed2001

Detection of APC and k-ras mutations in the serum of patients with colorectal cancer.

Detection of tumor DNA in peripheral blood of patients with colorectal cancer (CRC) may allow early diagnosis of tumor disease and be of prognostic value. However, a reliable tumor marker detectable in the serum of patients with this disease is missing. Because k-ras and APC mutations occur frequently and at an early stage in CRCs, these mutations might also be detected in the serum of CRC patients and serve as tumor markers. Hence, tumor tissues of CRC patients were examined for the presence of mutations in the k-ras and APC genes. If a mutation was detected in the tumor, the serum of the patient was screened subsequently for the presence of this mutation. K-ray mutations were detected in 22 of 30 colorectal tumor tissues, but only in six patients was the mutation identified in their serum samples. Mutations of the APC gene were identified in 25 of 65 tumors: 20 of these 25 patients showed the respective mutation in their serum. Given their higher detection rate, APC mutations could be a more informative serum marker than k-ras in CRC patients.

Adenocarcinoma↗

PubMed2000

Pain perception during self-reported distress and calmness in patients with borderline personality disorder and self-mutilating behavior.

Self-mutilation occurs in 70-80% of patients who meet DSM-IV criteria for borderline personality disorder. Approximately 60% of these patients report that they do not feel pain during acts of self-mutilation such as cutting or burning. Findings of recent studies measuring pain perception in patients with BPD are difficult to interpret since variables such as distress, dissociation or relevant psychotropic medication have not been controlled. The Cold Pressor Test (CPT) and the Tourniquet Pain Test (TPT) were administered to 12 female patients with BPD who reported analgesia during self-mutilation and 19 age-matched healthy female control subjects. All subjects were free of psychotropic medication. The patients were studied on two occasions: during self-reported calmness and during intensive distress (strong urge to cut or burn themselves). Even during self-reported calmness, patients with BPD showed a significantly reduced perception of pain compared to healthy control subjects in both tests. During distress, pain perception in BPD patients was further significantly reduced as compared with self-reported calmness. The present findings show that self-mutilating patients with BPD who experience analgesia during self-injury show an increased threshold for pain perception even in the absence of distress. This may reflect a state-independent increased pain threshold which is further elevated during stress. Interpretation of these findings is limited by their reliance upon self-reports.

Adult↗

PubMed2000

Reactive hyperemia in skin after cardiopulmonary bypass.

OBJECTIVE: To study reactive hyperemia (RH) using a transcutaneous PO2/PCO2 combination electrode heated to 37 degrees C and tissue reflectance spectrophotometry in patients before and after cardiopulmonary bypass (CPB) to determine whether microcirculatory function of skin is altered. DESIGN: Prospective study. SETTING: Anesthesiology and critical care unit of a university hospital. PARTICIPANTS: Eight patients undergoing elective CPB under mild hypothermia. INTERVENTIONS: To produce RH, blood flow to the forearm was prevented by inflation of a cuff to 300 mmHg for an interval of 5 minutes. MEASUREMENTS AND MAIN RESULTS: Measurements were obtained on the day prior to surgery (DPS), on the day of surgery (DOS) rewarmed to 37 degrees C in the intensive care unit (ICU), and on the first (POD 1) and the third postoperative days (POD 3). The following parameters were recorded: preocclusive baseline cutaneous PO2, and PCO2 (B-PtcO2, B-PtcCO2), and microvascular hemoglobin saturation (B-HbO2); postischemic peak of PtcO2, PtcCO2, and HbO2; and 10 minutes after release of the cuff occlusion posthyperemic PtcO2, PtcCO2, and HbO2. B-PtcO2 was 3.5 +/- 1.2 mmHg on DPS, 2.6 +/- 0.7 mmHg on DOS, 1.5 +/- 0.3 mmHg on POD 1, and 3.5 +/- 3.5 mmHg on POD 3. B-PtcCO2 increased significantly from 40.1 +/- 2.5 mmHg to 52.2 +/- 2.0 mmHg on DOS (p = 0.01) and to 48.9 +/- 3.6 mmHg on POD 1 (p = 0.02). On POD 3, B-PtcCO2 was 40.6 +/- 2.6 mmHg. B-HbO2 declined from a preoperative value of 42.4% +/- 8.6% to 37.1% +/- 14.7% on DOS and further to 21.7% +/- 4.8% on POD 1, which was significantly different (p = 0.03). On POD 3, B-HbO2 still remained lower (30.7% +/- 6.2%) compared with the preoperative value. RH (deltaPtcO2, deltaHBO2) was quantified as the differences between peak PtcO2, HBO2 and B-PtcO2, B-HBO2. DeltaPtcO2 was 13.0 +/- 2.3 on DPS, 11.3 +/- 2.9 on DOS, 12.6 +/- 2.6 on POD 1, and 11.5 +/- 3.5 on POD 3. DeltaHBO2 was 42.0 +/- 5.6 on DPS, 40.0 +/- 7.1 on DOS, 49.9 +/- 2.5 on POD 1, and 52.9 +/- 6.4 on POD 3. The elimination rate of carbon dioxide from skin (ECO2) was calculated as difference between peak PtcCO2 and PtcCO2 after 3 minutes of reperfusion divided by the difference between peak PtcCO2 and B-PtcCO2. ECO2 was 1.0 +/- 0.2 kPa/min on DPS, 0.7 +/- 0.1 kPa/min on DOS, and 0.8 +/- 0.1 kPa/min on POD 1 and POD 3. CONCLUSION: Cutaneous microcirculation assessed by RH is well preserved during the immediate postoperative period in patients undergoing uncomplicated coronary artery surgery with CPB.

Blood Gas Monitoring, Transcutaneous↗

PubMed2000

Vasopressin-mediated adrenocorticotropin release increases plasma cortisol concentrations during cardiopulmonary resuscitation.

OBJECTIVE: Vasopressin is a possible stimulus for both adrenocorticotropin (ACTH) and endothelin-1 release. The aim of this study was to compare plasma concentrations of ACTH, cortisol, and endothelin-1 after epinephrine or vasopressin administration in an experimental animal model of cardiopulmonary resuscitation (CPR). DESIGN: Prospective, randomized, controlled animal study. SETTING: A university research laboratory. SUBJECTS: Fourteen 12- to 14-wk-old domestic pigs. INTERVENTIONS: After 4 mins of cardiac arrest and 3 mins of external chest compression, the pigs were randomly assigned to receive either 0.045 mg/kg epinephrine (n = 7) or 0.4 units/kg vasopressin (n = 7). At 5 mins after drug administration, defibrillation was attempted. MEASUREMENTS AND MAIN RESULTS: Coronary perfusion pressure, ACTH, cortisol, and endothelin-1 were measured before cardiocirculatory arrest, during CPR before drug administration, and at 90 secs and 5 mins after drug administration. Coronary perfusion pressure was comparable between groups. All seven animals in the vasopressin group survived, but only one pig in the epinephrine group survived (p = .005). ACTH and cortisol concentrations remained unchanged in epinephrine-treated animals, but increased significantly after vasopressin administration and were significantly higher than in epinephrine-treated animals 5 mins after drug administration. Endothelin-1 concentrations remained unchanged during the study period and were comparable between both groups. CONCLUSIONS: Vasopressin is a potent stimulus for ACTH secretion, but does not trigger endothelin-1 release from vascular cells during cardiac arrest and CPR. The increased plasma cortisol concentrations caused by the enhanced ACTH release after vasopressin may be one factor contributing to the improved outcome repeatedly observed with vasopressin in animal models of CPR.

Adrenocorticotropic Hormone↗

PubMed1999

[Intestinal ischemic reperfusion syndrome: pathophysiology, clinical significance, therapy].

Gut ischemia-reperfusion injury is a serious condition in intensive care patients. Activation of immune cells within the huge endothelial surface area of gut microcirculation may initiate a systemic inflammatory response with secondary injury to distant organs. Translocation of bacteria and toxins through a leaky gut mucosa may amplify or perpetuate systemic inflammation, leading to multiple organ dysfunction syndrome and death in critically ill patients. Gut ischemia promotes regional production of inflammatory mediators, expression of cell adhesion molecules on endothelial and immune cell surfaces and increases the procoagulatory properties of vascular endothelial cells. During reperfusion, gut injury may be amplified by increased production of oxygen radicals and exhaustion of endogenous antioxidant defence mechanisms. Although several therapeutic strategies to interrupt the pathophysiology of ischemia-reperfusion have been shown to be beneficial in animal experiments, none of these interventions has gained clinical relevance. After initial hemodynamic and respiratory stabilisation of critically ill patients, strategies to prevent secondary gut injury by increasing splanchnic oxygen delivery or augment mucosal cell regeneration may be the only therapeutic options for intensive medical specialists at the present time. Early enteral nutrition and treatment with specific vasoactive drugs may reduce morbidity and costs of treatment in certain critically ill patients. However definitive evidence of a reduction in mortality with these therapies has still not be provided.

Animals↗

PubMed1999

Forced air surface rewarming in patients with severe accidental hypothermia.

Methods of rewarming patients with severe accidental hypothermia remain controversial. This paper reports our experience with the use of forced air rewarming in patients with severe accidental hypothermia and a body core temperature below 30 degrees C. Fifteen hypothermic patients (body core temperature 24-30 degrees C) were successfully treated with forced air rewarming to a body core temperature above 35 degrees C (mean rewarming rate 1.7 degrees C/h, range from 0.7 to 3.4 degrees C/h). An afterdrop phenomenon was not observed in any of the patients. Nine hypothermic patients (group 1) had no prehospital cardiac arrest, all nine were long-term survivors and made a full recovery. Six patients (group 2) had prehospital cardio circulatory arrest with restoration of spontaneous circulation. None of the group 2 patients survived long-term. Group 1 and group 2 patients did not differ in core temperature (26.6+/-1.6 degrees C group 1 and 27.0+/-1.8 degrees C group 2). Group 2 patients needed catecholamine support during rewarming more frequently (83 versus 22%) and had higher lactate levels and lower pH values at all points of observation. In conclusion our preliminary data indicate that forced air rewarming is an efficient and safe method of managing patients with severe accidental hypothermia. The poor outcome of patients with a history of prehospital cardiopulmonary resuscitation is probably due to irreversible ischaemic brain damage in primarily asphyxiated avalanche and near-drowning victims, rather than the consequence of the rewarming method used.

Adolescent↗