Another Role for Angiotensin II?: Vasopressin-Refractory Shock After Pheochromocytoma Resection: A Case Report.

A patient presented with multiple unrelated tumors and was found to have a small but functional adrenal pheochromocytoma. After pheochromocytoma resection, shock developed unresponsive to vasopressin in recommended doses (0.04 U/min infusion plus repeated 1-U boluses) but responded dramatically to an angiotensin II infusion (20 ng/kg/min) with a mean arterial pressure >100 mm Hg. The patient's blood pressure was maintained for 42 hours postoperatively with an infusion rate that ranged from 2 to 38 ng/kg/min. Because vasopressin may not always be effective for postresection shock in people with pheochromocytomas, angiotensin II may prove to be an effective alternative.

The response to methylene blue in patients with severe hypotension during liver transplantation.

Methylene blue is a useful therapy for catecholamine-resistant vasoplegic shock. Three cases of methylene blue administration for the treatment of catecholamine-resistant hypotension during orthotopic liver transplantation are presented.

Effects of geldanamycin and thalidomide on the Th1/Th2 cytokine balance in mice subjected to operative trauma.

BACKGROUND: Persistence of postoperative immune dysfunction is a critical problem because it increases the risk of serious infectious complications. The mechanisms of the immune dysfunction that occur initially after non-thermal operative injury remain to be fully elucidated. METHODS: Two mouse models of operative trauma (simple laparotomy to represent minor operative injury and ileocecal resection to represent major operative injury) were used to define the characteristics of initial cytokine synthesis. Geldanamycin and thalidomide were independently added intraperitoneally before and after operative injury to examine the effect on postoperative immune dysfunction. Mice were sacrificed at scheduled times (3, 6, 12, and 24 h after operative injury) and TNF-alpha, IL-2, IL-4, and IL-10 were analyzed. Spleen was used for intracellular cytokines and RT-PCR. Sera were used for ELISA. RESULTS: Major operative injury caused an initial upregulation of IL-10 synthesis with delayed synthesis of TNF-alpha and IL-2. Minor operative injury caused an early induction of IL-2 synthesis preceded by an initial induction of IL-4 synthesis. GA caused a specific early upregulation of TNF-alpha mRNA expression and intracellular TNF-alpha synthesis. The GA and THD groups showed early serum IL-2 production with reduction of IL-10 mRNA expression and intracellular IL-10 synthesis in the early post-operative phase. CONCLUSIONS: Major and minor operative injury showed different Th1/Th2 cytokine patterns in the initial post-operative period. Geldanamycin and thalidomide improved the Th1/Th2 imbalance independently after major operative injury.

Arginine-vasopressin in neonates with vasodilatory shock after cardiopulmonary bypass.

UNLABELLED: Successful therapy of vasodilatory shock in adults and children with arginine-vasopressin (AVP) has been reported previously. Data on the use of vasopressin in neonates is limited. This retrospective study reports the effects of AVP-treatment in neonates with catecholamine-resistant systemic vasodilatation after cardiopulmonary bypass. From March 2003 through December 2005, 172 neonates underwent open-heart surgery, 17 developed vasopressor-resistant hypotension and were treated with AVP. Thirteen patients had a stage I palliation of single ventricle, two had a Ross-operation and two had an arterial switch operation. All patients received multiple traditional inotropes and vasopressors prior to administration of AVP. AVP was started at median 0.0001 U x kg(-1) x min(-1) (range 0.00005-0.0002) and titrated up to a maximum of median 0.0003 U x kg(-1) x min(-1) (range 0.0001-0.001). AVP led to a significant increase in blood pressure (from 49+/-8 mmHg to 69+/-7 mmHg) and the requirement of traditional vasopressors decreased significantly. No peripheral vasoconstriction or ischemia was observed. Four of 13 patients, all with single ventricle palliation, died. In two patients death occurred due to additional complications 6 days after AVP was discontinued. One patient, who was still on AVP, died 42 hours postoperatively after prolonged hypoxemia not responding to inhaled nitric oxide. One patient arrested on the third postoperative day when AVP was almost weaned. CONCLUSION: In neonates with vasodilatory shock after cardiopulmonary bypass AVP is a potent agent to increase blood pressure when traditional vasopressors are failing.

Antidiuretic hormone replacement therapy to prevent or ameliorate vasodilatory shock.

Vasodilatory shock is a syndrome with high mortality. It is becoming evident that depletion of antidiuretic hormone (ADH) after cardiac surgery or during sepsis plays an important role in the pathogenesis of this condition. Established vasodilatory shock responds well to exogenous ADH infusion. It is possible that preventing ADH depletion at an earlier stage may abrogate the onset of vasodilatory shock, or at least reduce its severity. This paper examines the evidence supporting this concept, and the potential areas of concern in considering this particular type of hormone replacement therapy.

Vasopressin in the cardiac surgery intensive care unit.

Although nearly 10% of patients experience profound vasodilatory shock after cardiopulmonary bypass, some patients remain refractory to traditional resuscitation. Among this subset are patients who have inappropriately low levels of endogenous vasopressin. Thus, vasopressin replacement is an intuitively attractive intervention. The purposes of this review are to outline the pathophysiology of vasodilatory shock after cardiopulmonary bypass, to discuss the physiological role of endogenous vasopressin, to explore the clinical basis for vasopressin replacement, and to review the pharmacology and dosing guidelines.

Oxygen transport measurements to evaluate tissue perfusion and titrate therapy: dobutamine and dopamine effects.

BACKGROUND: Increased cardiac index, oxygen delivery (DO2), and oxygen consumption (VO2) patterns were shown to characterize the physiologic status of surviving high-risk surgical patients, and indicate increased metabolic needs; relatively normal DO2 and VO2 values were found to characterize the sequential pattern of nonsurvivors who developed an early oxygen debt followed by lethal organ failure. The cardiac index, DO2, and VO2 values empirically determined from survivors' patterns were shown to improve outcome in prospective randomized trials. The present study considers these criteria to evaluate the tissue perfusion status as well as the effects of therapy on tissue perfusion and oxygenation. OBJECTIVE: To summarize new information on the temporal patterns of DO2, VO2, and oxygen debt on outcome and the effects of fluids and inotropes on these patterns in a wide range of clinical, temporal, and physiologic conditions. DESIGN: Descriptive analysis based on data gathered prospectively using a specified protocol. PATIENTS: High-risk patients with accidental or elective surgical trauma, and patients with or without sepsis or septic shock and organ failure. SETTING: University-run county hospital with a large trauma service. INTERVENTIONS: Fluids, dobutamine, and dopamine at various times and at various doses throughout critical illness of postoperative, posttraumatic, septic, and hypovolemic patients with and without lethal and nonlethal organ failure. MEASUREMENTS AND MAIN RESULTS: The pattern of DO2 plotted against the corresponding VO2 values in 437 consecutive critically ill surgical patients showed a wide variability and poor correlation probably because complex clinical conditions may obscure the supply-dependent and supply-independent VO2 relationships observed in normal dogs bled or given bacterial infusions. However, the use of specific therapy by well-defined protocols was shown to provide objective evidence of efficacy. Significant increases in DO2 and VO2 were previously shown after whole blood, packed red cells, and colloid administration, but not after crystalloid administration. Dobutamine administration in 715 circumstances in postoperative, traumatic, septic patients and patients with adult respiratory distress syndrome, renal failure, and multiple organ failure significantly improved DO2 and VO2. Dopamine under comparable conditions produced less improvement in DO2 and VO2 than that of dobutamine; most of the VO2 changes were not significant. CONCLUSIONS: The monitored patterns of cardiac index, DO2, and VO2 may be used to evaluate the adequacy of tissue perfusion as well as the relative effectiveness of alternative therapies. Second, these physiologic criteria may be used to titrate therapy in order to achieve optimal outcome. Third, after colloids optimally expand the plasma volume, dobutamine may be used to enhance flow and the distribution of flow in order to improve tissue oxygenation. Vasodilators may be used when hypertensive episodes occur or there is an inadequate response to inotropic agents. Vasopressors are used as a last resort, usually in the terminal or preterminal state.

Effects of prostaglandin E1 in postoperative surgical patients with circulatory deficiency.

Hemodynamic and oxygen transport effects of PGE1 were observed in the early postoperative period before development of ARDS in two series of general surgical patients with circulatory deficiencies. The first was a series of 19 studies in 18 patients, the second was a placebo-controlled series of 20 patients (ten received PGE1 and ten received a placebo). In the first series, PGE1 was given as a trial of therapy after fluid therapy to pulmonary wedge pressures greater than 15 mm Hg failed to correct satisfactorily circulatory and metabolic functions. There were two deaths in the placebo group and none in the PGE1 group. Previous studies indicated that PGE1 disaggregates platelets and reduces local vasoconstriction in pulmonary circulation; this study suggests that PGE1 improves tissue perfusion of systemic circulation. After fluid therapy to PAOP greater than 15 mm Hg fails to restore circulatory function to optimal values. PGE1 should be considered as ancillary therapy in critically ill postoperative patients.

A comparison of intravenous access sites for bolus injections during shock and resuscitation after emergency room thoracotomy with and without aortic crossclamping.

Thoracotomy with aortic crossclamping is used to resuscitate trauma victims. Pharmacologic boluses are often given via intravenous lines of central, brachial, or femoral origin. This study was undertaken to determine the efficacy of intravenous access site on delivery of a bolus injection to the heart with thoracotomy and aortic crossclamping during shock and resuscitation. Six dogs were anesthetized, intubated, and underwent brachial and femoral venotomy and Swan-Ganz insertion (central). Baseline measurements of central, brachial, and femoral transit times for 10 cc cold saline were obtained via Swan-Ganz thermistor. Each animal then underwent thoracotomy, aortic crossclamping alone, hemorrhage to blood pressure (BP) 50 mm Hg for 30 minutes with aorta unclamped and then aorta crossclamped and resuscitation with lactated Ringer's Solution with aorta unclamped and then crossclamped. Femoral-Brachial Index (FBI) was determined by dividing femoral transit time by brachial transit time at each observation. The data suggest that femoral access significantly prolongs bolus transit time when compared with central or brachial access during aortic crossclamping in the euvolemic, shock, or aggressively resuscitated model. Brachial access is therefore the preferred route for bolus injection delivery in the emergency room thoracotomy with or without aortic crossclamping because it provides expedient bolus delivery equal to central access and superior to femoral access.

[Effect of biseptol on the adrenal cortex of the white rat in postoperative shock]. / Der Einfluss von Biseptol auf die Nebennierenrinde der weissen Ratte im postoperativen Schock.

The study aimed to find out the effect of sulfonamide combined with Trimetaprim-Biseptol 480 on the adrenal cortex in post-operative shock after removal of SPIGELian lobe (lobectomy of the lobus caudatus and unilaterally of one kidney with its suprarenal gland. The study was performed on a material of white rats which were post-operatively administered Biseptol 480 in doses 5 times bigger than those given to men. It was attempted to determine histochemically the intensity of the adrenal cortex' function by testing the number of lipid droplets, activity of the main enzyme of steroidogenesis (beta-hydroxy steroid dehydrogenase) and the level of alpha-ketols (as the final stage of steroidogenesis). Pathomorphologic examinations were also performe. On the basis of the present study's results, it was observed that - in the case of liver-lobectomy - the zona fasciculata and zona reticularis are functionally stimulated but the zona glomerulosa becomes insufficient. In the case of nephrectomy plus suprarenal gland's removal, all the adrenal cortex becomes insufficient. Administration of Biseptol in the 1st case contributed to hormonal inactivation of the zone glomerulosa cells, but in the 2nd case, it caused an increased activity of steroid dehydrogenase and an increase of the alpha-ketol level in the zona fasciculata.

Endogenous opioid peptides: critical care implications.

The recent evolution of our understanding of endogenous OPs has led to important new insights into the pathophysiology of many disease states. Opiate antagonism may provide the critical care physician with yet another lifesaving weapon. Opiate antagonists are not approved for human use in the various conditions discussed in this article; their use is strictly experimental and should be restricted to controlled trials. We look forward to continued research and clinical trials involving these agents.