Craniotomy during ECMO in a severely traumatized patient.

Extracorporeal membrane oxygenation (ECMO) can be a last resort treatment in acute respiratory distress syndrome after thoracic trauma. However, co-existent brain trauma is considered to be a contra-indication for ECMO. This is the first report on successful craniotomy under ECMO treatment in a multiply traumatized patient with severe thoracic and brain injuries. This successful treatment with beneficial neurological outcome suggests that ECMO therapy should not be withheld from severely injured patients with combined brain and thoracic trauma presenting with life-threatening hypoxemia. Moreover, even craniotomy may be performed during ECMO therapy without major bleeding and adverse effects on neurological function.

Arginine vasopressin and serum nitrite/nitrate concentrations in advanced vasodilatory shock.

BACKGROUND: Arginine-vasopressin (AVP) can successfully stabilize hemodynamics in patients with advanced vasodilatory shock. It has been suggested that inhibition of cytokine-induced nitric oxide production may be an important mechanism underlying AVP-induced vasoconstriction. Therefore, serum concentrations of nitrite/nitrate (NOx), the stable metabolite of nitric oxide, were measured in patients suffering from advanced vasodilatory shock treated with either AVP in combination with norepinephrine (NE) or NE alone. METHODS: This trial was a separate study arm of a previously published prospective, randomized, controlled study on the effects of AVP in advanced vasodilatory shock. Thirty-eight patients were prospectively randomized to receive a combined infusion of AVP (4 U h(-1)) and NE, or NE infusion alone. Serum NOx concentrations were measured at baseline, 24, and 48 h after randomization. The increase in mean arterial pressure during the first hour after study enrollment was documented in all patients. RESULTS: No difference in NOx concentrations was found between groups throughout the study period. AVP patients demonstrated a significantly greater increase in mean arterial pressure than NE patients (22 +/- 10 vs. 5 +/- 9 mmHg; P < 0.001). The magnitude of pressure response to AVP was not correlated with NOx concentrations before start of AVP infusion (Pearson's correlation coefficient, -.009; P = 0.971). CONCLUSION: Cardiovascular effects of AVP infusion in advanced vasodilatory shock are not mediated by a clinically relevant reduction in serum NOx concentrations. Therefore, hemodynamic improvement of patients in advanced vasodilatory shock during continuous infusion of AVP has to be attributed to other mechanisms than inhibition of nitric oxide synthase. In addition, the magnitude of pressure response to AVP is not correlated with baseline concentrations of NOx.

Oxygen distribution in microcirculation after arginine vasopressin-induced arteriolar vasoconstriction.

The microvascular distribution of oxygen was studied in the arterioles and venules of the awake hamster window chamber preparation to determine the contribution of vascular smooth muscle contraction to oxygen consumption of the microvascular wall during arginine vasopressin (AVP)-induced vasoconstriction. AVP was infused intravenously at the clinical dosage (0.0001 IU.kg(-1).min(-1)) and caused a significant arteriolar constriction, decreased microvascular flow and functional capillary density, and a substantial rise in arteriolar vessel wall transmural Po(2) difference. AVP caused tissue Po(2) to be significantly lowered from 25.4 +/- 7.4 to 7.2 +/- 5.8 mmHg; however, total oxygen extraction by the microcirculation increased by 25%. The increased extraction, lowered tissue Po(2), and increased wall oxygen concentration gradient are compatible with the hypothesis that vasoconstriction significantly increases vessel wall oxygen consumption, which in this model appears to constitute an important oxygen-consuming compartment. This conclusion was supported by the finding that the small percentage of the vessels that dilated in these experiments had a vessel wall oxygen gradient that was smaller than control and which was not determined by changes in tissue Po(2). These findings show that AVP administration, which reduces oxygen supply by vasoconstriction, may further impair tissue oxygenation by the additional oxygen consumption of the microcirculation.

Prospective observational study of antiphospholipid antibodies in acute lung injury and acute respiratory distress syndrome: comparison with catastrophic antiphospholipid syndrome.

Detection of antiphospholipid (aPL) antibodies in bronchoalveolar lavage fluid (BALF) of patient with acute respiratory distress syndrome (ARDS) suggests involvement of autoimmune mechanisms in the pathogenesis of ARDS. We investigated whether aPL antibodies could be detected in the serum as well as BALF of patients with acute lung injury (ALI) and ARDS. IgG anticardiolipin, IgG anti-beta2-glycoprotein I, IgG antiphosphatidic acid and IgG antiphosphatidylserine antibodies were detected by ELISA in low titers within the normal range in the BALF and serum of nine patients with ALI and 17 patients with ARDS. However, one out of 27 patients investigated had high levels of aPL antibodies in both BALF and serum. This patient suffered from severe ARDS due to sepsis. The high aPL antibody levels in serum possibly triggered by sepsis were associated with high aPL antibody levels in BALF, which can be explained by high capillary-alveolar permeability. Computed tomography scan revealed widespread infarctions in brain, spleen and kidneys, and pulmonary thromboembolism, suggesting the diagnosis of catastrophic antiphospholipid syndrome.

Cardiac failure and multiple organ dysfunction syndrome in a patient with endocrine adenomatosis.

In this case report, we present the successful therapy of severe cardiac failure in pituitary adrenal insufficiency. A previously healthy 56-year-old-man in pituitary coma due to an atypical variant of multiple endocrine adenomatosis (pituitary adenoma and pheochromocytoma) suffered from cardiac failure resistant to catecholamine and standard hydrocortisone therapy. After two bolus injections of dexamethasone (2 x 24 mg) mean arterial pressure and cardiac function dramatically improved, probably due to restoration of permissive effects on catecholamine action and reversal of pathophysiological mechanisms of cardiac failure. We conclude that in patients with severe cardiovascular failure in pituitary coma the administration of potent glucocorticoids may be more effective in reversing cardiovascular failure than standard dosages of hydrocortisone.

[Arginine vasopressin in vasodilatory shock: a new therapy approach?]. / Arginin-Vasopressin im vasodilatatorischen Schock Ein neuer Therapieansatz?

Catecholamines are currently the most often used vasopressor agents in the treatment of vasodilatory shock. However, progressive catecholamine resistance is a feared complication. Recent studies have shown that arginine vasopressin, an endogenous hormone of the neurohypophysis, may be a potent vasopressor when used in combination with catecholamines. During catecholamine-resistant septic and postcardiotomy shock, argine vasopressin results in a significant increase in mean arterial pressure as well as a significant decrease in heart rate and vasopressor requirements. In the guidelines of both the "American Heart Association" and the "International Liaison Committee on Resuscitation" from the year 2000, arginine vasopressin is recommended as a possibly helpful agent in therapy refractory vasodilatory septic shock. There is currently limited data on possible side effects of a continuous arginine vasopressin therapy in vasodilatory shock. Therefore, arginine vasopressin should be restricted to patients where adequate stabilization of hemodynamic function cannot be achieved by conventional vasopressor therapy alone.

Cardiac performance during vasopressin infusion in postcardiotomy shock.

OBJECTIVE: Arginine-vasopressin (AVP) might be a potent vasopressor agent in catecholamine-resistant postcardiotomy shock. However, its use remains experimental because of considerations about deleterious effects on the heart. We report on the effects of continuous AVP-infusion on cardiac performance, biomarkers of myocardial ischemia, and systemic hemodynamics in catecholamine-resistant postcardiotomy shock. DESIGN: Retrospective study. SETTING: Twenty-one-bed general and surgical intensive care unit. PATIENTS: Forty-one patients with catecholamine-resistant postcardiotomy shock. INTERVENTIONS: Continuous infusion of AVP. MEASUREMENTS AND RESULTS: Heart rate (HR), heart rhythm, mean arterial pressure (MAP), central venous pressure, mean pulmonary arterial pressure, cardiac index (CI), stroke volume index (SVI), left ventricular stroke work index (LVSWI), systemic vascular resistance (SVR) as well as milrinone and norepinephrine requirements were collected before and 1, 4, 12, 24, and 48 h after start of AVP infusion. Creatine kinase MB and troponin-I serum concentrations were measured daily. During AVP administration we observed a significant decrease in HR (-14.8%), milrinone (-17.5%), and norepinephrine requirements (-54.9%) as well as biomarkers of cardiac ischemia and a significant increase in LVSWI (+46.2%), MAP (+41.8%) and SVR (+60%). CI and SVI remained unchanged. Forty-five percent of postoperative new-onset tachyarrhythmias (TA) converted into sinus rhythm during AVP infusion. CONCLUSIONS: AVP was devoid of adverse effects on the heart in these patients with catecholamine-resistant postcardiotomy shock. The significant reduction in HR, vasopressor, and inotropic support suggest a substantial improvement in myocardial performance. These findings are supported by a significant decrease of cardiac enzymes and cardioversion of TA into sinus rhythm in 45.5% of patients with new-onset TA.

Antifactor Xa activity in intensive care patients receiving thromboembolic prophylaxis with standard doses of enoxaparin.

BACKGROUND: Low-molecular-weight heparins (LMWHs) have become increasingly used to prevent thromboembolic complications in intensive care patients. Unlike in medical and surgical patients, no data on the anticoagulant effectiveness of standard LMWH dosages exist in intensive care patients. Therefore, we prospectively investigated antifactor Xa (aFXa) levels after subcutaneous administration of 40 mg of enoxaparin in 89 intensive care patients over a 24-h period. METHODS: AFXa levels were measured before, 4, 12 and 24 h after subcutaneous administration of enoxaparin. Laboratory parameters including prothrombin time, activated partial thromboplastin time, antithrombin III, fibrinogen as well as platelet count were collected at same intervals. Demographics included age, sex, height, weight, body mass index, admission diagnosis, a thromboembolic risk score and a modified Goris multiple organ dysfunction score. RESULTS: At 4, 12 and 24 h, 56.5%, 39.3% and 12.6% of the study patients were within recommended antithrombotic aFXa levels (0.1-0.3 U ml(-1)). Presence of multiple organ dysfunction as well as high body weight were significantly correlated with low aFXa levels. CONCLUSION: European standard dosages of 40 mg of enoxaparin once daily proved to be ineffective in achieving recommended antithrombotic aFXa levels in intensive care patients. This was most pronounced in patients with high body weight and presence of multiple organ dysfunction.

The effects of vasopressin on systemic hemodynamics in catecholamine-resistant septic and postcardiotomy shock: a retrospective analysis.

UNLABELLED: We retrospectively investigated the effects of continuous arginine vasopressin (AVP) infusion on systemic hemodynamics, acid/base status, and laboratory variables in patients (mean age [mean +/- SD]= 66.3 +/- 10.1 yr) with catecholamine-resistant septic (n = 35) or postcardiotomy shock (n = 25). Hemodynamic and acid/base data were obtained before; 30 min after; and 1, 4, 12, 24, 48, and 72 h after the start of AVP infusion. Laboratory examinations were recorded before and 24, 48, and 72 h after the start of AVP infusion. For statistical analysis, a mixed-effects model was used. The overall intensive care unit mortality was 66.7%. AVP administration caused a significant increase in mean arterial pressure (+29%) and systemic vascular resistance (+56%), accompanied by a significant decrease in heart rate (-24%) and mean pulmonary arterial pressure (-11%) without any change in stroke volume index. Norepinephrine requirements could be reduced by 72% within 72 h. During AVP infusion, a significant increase in liver enzymes and total bilirubin concentration and a significant decrease in platelet count occurred. Arginine vasopressin was effective in reversing systemic hypotension. However, adverse effects on gastrointestinal perfusion and coagulation cannot be excluded. IMPLICATIONS: In this retrospective analysis, the influence of a continuous infusion of an endogenous hormone (arginine vasopressin) on systemic hemodynamics and laboratory variables was assessed in patients with vasodilatory shock unresponsive to conventional therapy. Arginine vasopressin was effective in reversing systemic hypotension. However, adverse effects on gastrointestinal perfusion and coagulation cannot be excluded.

Detection of human cytomegalovirus in ocular tissue by polymerase chain reaction and in situ DNA hybridization.

Rapid and sensitive techniques with a high degree of accuracy are necessary for the diagnosis and management of cytomegalovirus (CMV) retinitis presenting with atypical clinical manifestations. Light microscopy and immunohistochemical studies have limitations in the identification of this virus, but in situ DNA hybridization offers a rapid, highly specific, and easily interpretable means of identifying CMV. A new procedure of enzymatic amplification of DNA in vitro, called the polymerase chain reaction (PCR), has yielded excellent results in the identification of various viruses. In the study described herein, we evaluated the diagnostic usefulness of PCR and compared its reliability with that of in situ DNA hybridization for the detection of CMV in ocular tissues. We found that the reliability of the PCR method is similar to in situ DNA hybridization for the detection of CMV, although morphologic correlation is provided only by the latter technique. False-negative results can occur in PCR if the correct primer is not used.

DNA of human papillomavirus type 16 in dysplastic and malignant lesions of the conjunctiva and cornea.

Human papillomaviruses are receiving attention for their role in the pathogenesis of cancer, especially cancer of the anogenital tract. Although strains of human papillomavirus are associated with benign lesions of the conjunctiva, their association with conjunctival dysplastic lesions and carcinomas has remained unclear. We examined a group of neoplastic lesions of the conjunctiva for the presence of DNA sequences for human papillomavirus types 16 and 18, using in vitro gene amplification with the polymerase chain reaction. Tissue specimens of five conjunctival dysplastic lesions and one invasive carcinoma and swab specimens of the mucosa of both corneas of a patient with unilateral corneal dysplasia contained DNA sequences related to human papillomavirus type 16. All dysplastic specimens examined were positive for DNA sequences. Viral DNA was not detected in six control specimens from patients with conjunctival melanoma, papilloma, nevus, or pterygium. We conclude that DNA from human papillomavirus type 16 is present in a substantial percentage of conjunctival premalignant and malignant lesions. It may play a part in the development of conjunctival dysplasia and carcinoma, as it does in cancers of certain other body sites.