The course of adrenomedullin and endothelin levels in patients with vasodilatory shock after cardiac surgery compared to patients after uncomplicated elective cardiac surgery.

PURPOSE: The aim of this study was to analyse the course of adrenomedullin (ADM) and endothelin-1 (ET-1) levels in patients with vasodilatory shock after cardiac surgery and to explore differences compared to patients after uncomplicated coronary artery bypass graft (CABG) surgery. ADM and ET-1 are involved in the vasomotor response during vasodilatory shock. MATERIALS AND METHODS: We included 32 patients with vasodilatory shock (study group) and 10 patients after uncomplicated CABG surgery (control group). Daily measurements of MR-proADM and CT-proET-1 (stable surrogate markers for ADM and ET-1) were collected during the first 7 postoperative days. RESULTS: MR-proADM and CT-proET-1 levels were significantly elevated in the study group when compared to the control group. In addition, the course of both biomarkers was significantly different in the study versus control group. Higher levels of both biomarkers were associated with organ dysfunction (higher maximum multiple organ dysfunction score, acute kidney injury). CONCLUSIONS: Significantly higher levels of MR-proADM and CT-proET-1 and a different course of both biomarkers were observed in patients with vasodilatory shock after cardiac surgery and seemed to be associated with organ dysfunction.

Anesthesia-Induced Oxidative Stress: Are There Differences between Intravenous and Inhaled Anesthetics?

Agents used for the induction of anesthesia have been shown to either promote or mitigate oxidative stress. A fine balance between the presence of reactive oxygen species (ROS) and antioxidants is crucial for the proper normal functioning of the cell. A basal concentration of ROS is essential for the manifestation of cellular functions, whereas disproportionate levels of ROS cause damage to cellular macromolecules such as DNA, lipids, and proteins, eventually leading to necrosis and apoptosis. Increased ROS has been linked with numerous illnesses, such as cardiovascular, immune system, liver, and kidney, and has been shown to promote cancer and accelerate aging. Knowledge of the various pharmacologic agents that increase or reduce oxidative stress may promote a safer way of inducing anesthesia. Furthermore, surgery itself leads to increased ROS production and ischemia/reperfusion injury. Indeed, increased perioperative oxidative stress has been correlated with increased postoperative complications and prolonged recovery. Anesthesiologists care for patients during the whole spectrum of perioperative care and thus are in a unique position to deliver countermeasures to oxidative stress. Using preferentially an induction agent which reduces oxidative stress might lead to better clinical outcomes and fewer postoperative complications. Propofol has been shown in several studies to reduce oxidative stress, which reduces postoperative complications and leads to a faster recovery, and thus might represent the preferred induction agent in the right clinical setting.

Histologic pathologies of the myocardium in septic shock: a prospective observational study.

Myocardial depression in septic shock is well known, but its pathophysiological genesis is incompletely understood. To assess the incidence and extent of stress-induced histologic myocardial alterations in septic shock, a prospective, observational, combined clinical and postmortem study was conducted, and 20 patients dying from septic shock were included. Exclusion criteria were younger than 18 years, pregnancy, open heart surgery or cardiopulmonary resuscitation, acute neurologic diseases, pheochromocytoma, and forensic autopsy. A systematic macropathologic evaluation was performed. Nine predefined heart sections were histologically screened for myocytolysis, interstitial fibrosis, contraction band necrosis, mononuclear infiltrates, interstitial edema, and tissue hemorrhage. Stress-induced pathologies were found in 90% to 100% of patients in all heart sections (myocytolysis, 100%; interstitial fibrosis, 100%; contraction band necrosis, 95%; mononuclear infiltrates, 90%; interstitial edema, 90%; tissue hemorrhage, 30%). The incidence and extent of contraction band necrosis, mononuclear infiltrates, and myocytolysis did not differ between sexes; patients with or without chronic ß-blocker, calcium antagonist, and/or statin premedication; or between the binary use of different catecholamine agents (all comparisons P > 0.05). The maximum epinephrine dose correlated with the overall extent of mononuclear infiltrates (Spearman-Rho, r = 0.704; P = 0.05) and myocytolysis (Spearman-Rho, r = 0.933; P = 0.001). Maximum norepinephrine doses correlated with the extent of mononuclear infiltrates in the left ventricular anterior wall (Spearman-Rho, r = 0.519; P = 0.02). The total duration of catecholamine therapy was correlated with the extent of mononuclear infiltrates in the apex (Spearman-Rho, r = 0.571; P = 0.009) and right atrium (Spearman-Rho, r = 0.535; P = 0.02). In conclusion, our results suggest that histologic lesions potentially indicative of stress-induced cardiotoxicity can be observed in most patients dying from septic shock.

Adverse cardiac events during catecholamine vasopressor therapy: a prospective observational study.

PURPOSE: To determine the incidence of and risk factors for adverse cardiac events during catecholamine vasopressor therapy in surgical intensive care unit patients with cardiovascular failure. METHODS: The occurrence of any of seven predefined adverse cardiac events (prolonged elevated heart rate, tachyarrhythmia, myocardial cell damage, acute cardiac arrest or death, pulmonary hypertension-induced right heart dysfunction, reduction of systemic blood flow) was prospectively recorded during catecholamine vasopressor therapy lasting at least 12 h. RESULTS: Fifty-four of 112 study patients developed a total of 114 adverse cardiac events, an incidence of 48.2 % (95 % CI, 38.8-57.6 %). New-onset tachyarrhythmia (49.1 %), prolonged elevated heart rate (23.7 %), and myocardial cell damage (17.5 %) occurred most frequently. Aside from chronic liver diseases, factors independently associated with the occurrence of adverse cardiac events included need for renal replacement therapy, disease severity (assessed by the Simplified Acute Physiology Score II), number of catecholamine vasopressors (OR, 1.73; 95 % CI, 1.08-2.77; p = 0.02) and duration of catecholamine vasopressor therapy (OR, 1.01; 95 % CI, 1-1.01; p = 0.002). Patients developing adverse cardiac events were on catecholamine vasopressors (p < 0.001) and mechanical ventilation (p < 0.001) for longer and had longer intensive care unit stays (p < 0.001) and greater mortality (25.9 vs. 1.7 %; p < 0.001) than patients who did not. CONCLUSIONS: Adverse cardiac events occurred in 48.2 % of surgical intensive care unit patients with cardiovascular failure and were related to morbidity and mortality. The extent and duration of catecholamine vasopressor therapy were independently associated with and may contribute to the pathogenesis of adverse cardiac events.

Concomitant arginine-vasopressin and hydrocortisone therapy in severe septic shock: association with mortality.

PURPOSE: To evaluate the association between concomitant arginine-vasopressin (AVP)/hydrocortisone therapy and mortality in severe septic shock patients. METHODS: This retrospective study included severe septic shock patients treated with supplementary AVP. To test the association between concomitant AVP/hydrocortisone use and mortality, a multivariate regression and Cox model (adjusted for admission year, initial AVP dosage and the Sepsis-related Organ Failure Assessment score before AVP) as well as a propensity score-based analysis were used. In both models, intensive care unit (ICU) and 28-day mortality served as outcome variables. RESULTS: One hundred fifty-nine patients were included. Hydrocortisone was administered to 76 (47.8%) at a median daily dosage of 300 (200-300) mg. In the multivariate logistic regression model, concomitant use of AVP and hydrocortisone was associated with a trend towards lower ICU (OR, 0.51; CI 95%, 0.24-1.08; p = 0.08) and 28-day (HR, 0.69; CI 95%, 0.43-1.08; p = 0.11) mortality. The probability of survival at day 28, as predicted by the regression model, was significantly higher in patients treated with concomitant AVP and hydrocortisone compared to those receiving AVP without hydrocortisone (p = 0.001). In a propensity score-based analysis, ICU (45 vs. 65%; OR, 0.69; CI 95% 0.38-1.26; p = 0.23) and 28-day mortality (35.5 vs. 55%; OR, 0.59; CI 95%, 0.27-1.29; p = 0.18) was not different between patients treated with (n = 40) or without concomitant hydrocortisone (n = 40). CONCLUSION: Concomitant AVP and hydrocortisone therapy may be associated with a survival benefit in septic shock. An adequately powered, randomised controlled trial appears warranted to confirm these preliminary, hypothesis-generating results.

Head-position angles in children for opening the upper airway.

AIMS: Inexperienced health-care-providers may encounter severe problems to ventilate an unconscious child. Designing a ventilating device that could indicate how to open an upper airway correctly may be beneficial. Neutral position in young children and slight head extension in older children is recommended, although the optimal head angle is not clear. Thus, we compared effects of neutral head position and extension, measuring head-position angles and ventilation parameters. METHODS: Sixty-one children scheduled for tonsillectomy were enrolled, and were ventilated with pressure-controlled ventilation after anaesthesia induction. RESULTS: Children were divided into two groups: 1-5 years old (pre-school children, n=38) and 6-10 years old (school children, n=23). In neutral (mean+/-SD: 1.3+/-6.0) vs. head-extension position (13.2+/-6.0; P<0.001) in pre-school children, tidal volumes (132+/-44,137+/-49 ml), peak-expiratory flow (300+/-90 vs. 310+/-100 mls(-1)) and expiratory airway resistance (20+/-8 vs. 18+/-6c mH(2)O s l(-1)) were comparable (P=NS). In neutral (-0.4+/-5.4) vs. head-extension position (15.7+/-6.4; P<0.001) in school children, expiratory airway resistance (17+/-7 vs. 13+/-5 cmH(2)O s l(-1); P=0.048) differed, while tidal volume (224+/-93 vs. 230+/-92 ml) and peak-expiratory flow (427+/-181 vs. 381+/-144 ml s(-1)) were comparable (P=NS). CONCLUSIONS: Head-extension and neutral head-position angles differed in pre-school and school children. In pre-school children, neutral head position or head extension with an angle of -1 degrees or 13 degrees , and in school children head extension of 16 degrees , may be used to achieve optimal ventilation of an unprotected airway.

Comparing two different arginine vasopressin doses in advanced vasodilatory shock: a randomized, controlled, open-label trial.

PURPOSE: To compare the effects of two arginine vasopressin (AVP) dose regimens on the hemodynamic response, catecholamine requirements, AVP plasma concentrations, organ function and adverse events in advanced vasodilatory shock. METHODS: In this prospective, controlled, open-label trial, patients with vasodilatory shock due to sepsis, systemic inflammatory response syndrome or after cardiac surgery requiring norepinephrine >0.6 microg/kg/min were randomized to receive a supplementary AVP infusion either at 0.033 IU/min (n = 25) or 0.067 IU/min (n = 25). The hemodynamic response, catecholamine doses, laboratory and organ function variables as well as adverse events (decrease in cardiac index or platelet count, increase in liver enzymes or bilirubin) were recorded before, 1, 12, 24 and 48 h after randomization. A linear mixed effects model was used for statistical analysis in order to account for drop-outs during the observation period. RESULTS: Heart rate and norepinephrine requirements decreased while MAP increased in both groups. Patients receiving AVP at 0.067 IU/min required less norepinephrine (P = 0.006) than those infused with AVP at 0.033 IU/min. Arterial lactate and base deficit decreased while arterial pH increased in both groups. During the observation period, AVP plasma levels increased in both groups (both P < 0.001), but were higher in the 0.067 IU/min group (P < 0.001) and in patients on concomitant hydrocortisone. The rate of adverse events and intensive care unit mortality was comparable between groups (0.033 IU/min, 52%; 0.067 IU/min, 52%; P = 1). CONCLUSIONS: A supplementary AVP infusion of 0.067 IU/min restores cardiovascular function in patients with advanced vasodilatory shock more effectively than AVP at 0.033 IU/min.

A survey of the status of education and research in anaesthesia and intensive care medicine at the University Teaching Hospital in Lusaka, Zambia.

BACKGROUND: Current knowledge of the situation of anaesthesia in developing countries is limited. A survey of the status of education and research based on hospital records, records of the anaesthesia section, nursing records, personal observations as well as personal communication with staff, patients and hospital managers was carried out in a 1863-bed university teaching hospital located in the capital of a least developed Sub-Saharan African Country. METHODS: Classification and evaluation of the data was based on the three aspects of the role of university teaching hospitals in Western countries: (I) patient care, (II) university teaching and post-graduation training, as well as (III) research activities. The section "patient care" was sub-divided into anaesthesia, intensive care medicine, emergency medicine, and pain therapy. The Department of Anaesthesia at the University Teaching Hospital of Lusaka, Zambia, is organized as a subdivision of the surgical department and is not involved in emergency medicine or pain therapy. Thirteen out of seventeen operating theatres, one recovery room, and a ten bed intensive care unit are serviced by the Department of Anaesthesia. RESULTS: Anaesthetic equipment, medical supplies, drugs, and consumables are all in limited supply. There are limited statistics on perioperative complications and mortality. Anaesthesia at the university teaching hospital of a least developed Sub-Saharan African Country is severely short of both a workforce and resources. CONCLUSION: We have described strategies which may help to reverse this trend, the most important of which is to promote anaesthesia as an essential specialty within hospitals in developing countries.

Macroscopic postmortem findings in 235 surgical intensive care patients with sepsis.

BACKGROUND: Although detailed analyses of the postmortem findings of various critically ill patient groups have been published, no such study has been performed in patients with sepsis. In this retrospective cohort study, we reviewed macroscopic postmortem examinations of surgical intensive care unit (ICU) patients who died from sepsis or septic shock. METHODS: Between 1997 and 2006, the ICU database and autopsy register were reviewed for patients who were admitted to the ICU because of sepsis/septic shock, or who developed sepsis/septic shock at a later stage during their ICU stay and subsequently died from of sepsis/septic shock. Clinical data and postmortem findings were documented in all patients. RESULTS: Postmortem results of 235 patients (84.8%) were available for statistical analysis. The main causes of death as reported in the patient history were refractory multiple organ dysfunction syndrome (51.5%) and uncontrollable cardiovascular failure (35.3%). Pathologies were detected in the lungs (89.8%), kidneys/urinary tract (60%), gastrointestinal tract (54%), cardiovascular system (53.6%), liver (47.7%), spleen (33.2%), central nervous system (18.7%), and pancreas (8.5%). In 180 patients (76.6%), the autopsy revealed a continuous septic focus. The most common continuous foci were pneumonia (41.3%), tracheobronchitis (28.9%), peritonitis (23.4%), uterine/ovarial necrosis (9.8% of female patients), intraabdominal abscesses (9.1%), and pyelonephritis (6%). A continuous septic focus was observed in 63 of the 71 patients (88.7%) who were admitted to the ICU because of sepsis/septic shock and treated for longer than 7 days. CONCLUSIONS: Relevant postmortem findings explaining death in surgical ICU patients who died because of sepsis/septic shock were a continuous septic focus in approximately 80% and cardiac pathologies in 50%. The most frequently affected organs were the lungs, abdomen, and urogenital tract. More diagnostic, therapeutic and scientific efforts should be launched to identify and control the infectious focus in patients with sepsis and septic shock.

Arterial blood pressure during early sepsis and outcome.

OBJECTIVE: To evaluate the association between arterial blood pressure (ABP) during the first 24 h and mortality in sepsis. DESIGN: Retrospective cohort study. SETTING: Multidisciplinary intensive care unit (ICU). PATIENTS AND PARTICIPANTS: A total of 274 septic patients. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Hemodynamic, and laboratory parameters were extracted from a PDMS database. The hourly time integral of ABP drops below clinically relevant systolic arterial pressure (SAP), mean arterial pressure (MAP), and mean perfusion pressure (MPP = MAP - central venous pressure) levels was calculated for the first 24 h after ICU admission and compared with 28-day-mortality. Binary and linear regression models (adjusted for SAPS II as a measure of disease severity), and a receiver operating characteristic (ROC) analysis were applied. The areas under the ROC curve were largest for the hourly time integrals of ABP drops below MAP 60 mmHg (0.779 vs. 0.764 for ABP drops below MAP 55 mmHg; P < or = 0.01) and MPP 45 mmHg. No association between the hourly time integrals of ABP drops below certain SAP levels and mortality was detected. One or more episodes of MAP < 60 mmHg increased the risk of death by 2.96 (CI 95%, 1.06-10.36, P = 0.04). The area under the ROC curve to predict the need for renal replacement therapy was highest for the hourly time integral of ABP drops below MAP 75 mmHg. CONCLUSIONS: A MAP level > or = 60 mmHg may be as safe as higher MAP levels during the first 24 h of ICU therapy in septic patients. A higher MAP may be required to maintain kidney function.

The vasopressin and copeptin response in patients with vasodilatory shock after cardiac surgery: a prospective, controlled study.

OBJECTIVE: To evaluate arginine vasopressin (AVP) and copeptin plasma concentrations in patients with vasodilatory shock after cardiac surgery. DESIGN: Prospective, controlled, clinical study. SETTING: Surgical intensive care unit and cardiac surgery ward in a tertiary university teaching hospital. PATIENTS AND PARTICIPANTS: Thirty-three critically ill patients with vasodilatory shock after cardiac surgery and ten control patients undergoing uncomplicated aorto-coronary bypass surgery. MEASUREMENTS AND RESULTS: Hemodynamic, laboratory and clinical data were recorded daily in all patients during the first 7 days after cardiac surgery. At the same time, points blood was withdrawn to determine plasma concentrations of AVP (radioimmunoassay) and copeptin (immunoluminometric assy). Standard tests, a mixed effects model and regression analyses were used for statistical analysis. The course of AVP was significantly different between groups (P < 0.001). While AVP concentrations were lower in the study group on the first postoperative day, they were higher than that in the control group from postoperative day 3 on. There was no difference in the postoperative AVP response between study patients with or without chronic angiotensin-converting enzyme inhibitor therapy. Except during continuous veno-venous hemofiltration, AVP and copeptin correlated significantly with each other (P < 0.001; r = 0.749). CONCLUSIONS: The AVP response to cardiac surgery is significantly different between patients with vasodilatory shock and patients undergoing uncomplicated aorto-coronary bypass surgery. Although no causative relationship between AVP concentrations and cardiovascular instability can be drawn from these results, our data support the hypothesis that inadequately low AVP plasma levels contribute to the failure to restore vascular tone in vasodilatory shock after cardiac surgery.

Postoperative vasopressin and copeptin levels in noncardiac surgery patients: a prospective controlled trial.

Further information on the endogenous arginine vasopressin (AVP) response in patients with postoperative systemic inflammatory response syndrome (SIRS) and vasodilatory shock would provide more insight into the pathophysiology of SIRS-associated cardiovascular failure and help indicate AVP therapy. Patients after uncomplicated abdominal surgery without SIRS (n = 10), critically ill patients after noncardiac surgery with SIRS (n = 9), and patients with SIRS plus vasodilatory shock (n = 22) were included in this prospective trial. Plasma AVP (radioimmunoassay) and copeptin (immunoluminometric assay) concentrations together with clinical parameters were documented daily during the first 7 days postoperative. The AVP response significantly differed between the three groups. Patients without SIRS had lower AVP concentrations than SIRS patients with (P = 0.001) or without shock (P = 0.003). Patients with SIRS and shock had higher AVP levels than patients with SIRS alone (P < 0.001). Arginine vasopressin decreased over time (P = 0.007) in all groups. At day 28, nonsurvivors had higher AVP levels than did survivors (P < 0.001). In SIRS patients without shock, serum osmolarity was indirectly associated with AVP levels, whereas mean arterial blood pressure and serum osmolarity were associated with AVP in SIRS patients with shock. Arginine vasopressin and copeptin correlated significantly with each other (P < 0.001; r = 0.76). In patients without hemofiltration, copeptin levels predicted 28-day mortality with high sensitivity and specificity. The postoperative AVP response in noncardiac surgery patients seems well maintained. The possibility that AVP plays a contributory role in the failure to restore vascular tone in patients with vasodilatory shock cannot be excluded but seems less important than in septic or postcardiotomy shock.

The vasopressin and copeptin response to infection, severe sepsis, and septic shock.

OBJECTIVE: To compare the course of arginine vasopressin (AVP) and copeptin plasma concentrations between patients with infection, severe sepsis, and septic shock. DESIGN: Prospective, closed-cohort study. SETTING: Twelve-bed general and surgical intensive care unit and 33-bed internal medicine ward in a university hospital. PATIENTS: Ten patients with infection, 22 with severe sepsis, and 28 with septic shock. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Hemodynamic, laboratory and clinical data were recorded daily during the first 7 days after intensive care unit or hospital admission. Parallel thereto, blood was withdrawn to determine plasma AVP (radioimmunoassay) and copeptin (immunoluminometric assay) concentrations. Standard tests, a mixed effects model, and a linear regression analysis were used for statistical analysis. The AVP response was different between the three study groups (p < 0.001) but did not change over time (p = 0.12). Although patients with severe sepsis and septic shock had higher AVP levels than did patients with infection (both p < 0.001), no difference in AVP concentrations was seen between severe sepsis and septic shock patients (p = 0.98). No difference in AVP was observed between survivors and nonsurvivors at day 28 (p = 0.87). In patients with severe sepsis, serum osmolarity (p < 0.001), arterial pH (p = 0.001), lactate (p < 0.001), and Pao2 (p = 0.04) were associated with the course of AVP plasma levels, whereas it was serum osmolarity alone in patients with septic shock (p = 0.03). Plasma AVP concentrations correlated with copeptin (r = .614, p < 0.001), but this correlation was influenced by continuous veno-venous hemofiltration (p = 0.002). CONCLUSIONS: Severe sepsis induced a stronger AVP response than infection without systemic inflammation. However, the lack of a difference in AVP plasma concentrations between patients with and without shock indicates that the AVP system does not function normally in severe sepsis. Our data support the hypothesis that impaired AVP response is at least partially responsible for the failure to restore vascular tone in septic shock.

Combined milrinone and enteral metoprolol therapy in patients with septic myocardial depression.

INTRODUCTION: The multifactorial etiology of septic cardiomyopathy is not fully elucidated. Recently, high catecholamine levels have been suggested to contribute to impaired myocardial function. METHODS: This retrospective analysis summarizes our preliminary clinical experience with the combined use of milrinone and enteral metoprolol therapy in 40 patients with septic shock and cardiac depression. Patients with other causes of shock or cardiac failure, patients with beta-blocker therapy initiated more than 48 hours after shock onset, and patients with pre-existent decompensated congestive heart failure were excluded. In all study patients, beta blockers were initiated only after stabilization of cardiovascular function (17.7 +/- 15.5 hours after shock onset or intensive care unit admission) in order to decrease the heart rate to less than 95 beats per minute (bpm). Hemodynamic data and laboratory parameters were extracted from medical charts and documented before and 6, 12, 24, 48, 72, and 96 hours after the first metoprolol dosage. Adverse cardiovascular events were documented. Descriptive statistical methods and a linear mixed-effects model were used for statistical analysis. RESULTS: Heart rate control (65 to 95 bpm) was achieved in 97.5% of patients (n = 39) within 12.2 +/- 12.4 hours. Heart rate, central venous pressure, and norepinephrine, arginine vasopressin, and milrinone dosages decreased (all P < 0.001). Cardiac index and cardiac power index remained unchanged whereas stroke volume index increased (P = 0.002). In two patients (5%), metoprolol was discontinued because of asymptomatic bradycardia. Norepinephrine and milrinone dosages were increased in nine (22.5%) and six (15%) patients, respectively. pH increased (P < 0.001) whereas arterial lactate (P < 0.001), serum C-reactive protein (P = 0.001), and creatinine (P = 0.02) levels decreased during the observation period. Twenty-eight-day mortality was 33%. CONCLUSION: Low doses of enteral metoprolol in combination with phosphodiesterase inhibitors are feasible in patients with septic shock and cardiac depression but no overt heart failure. Future prospective controlled trials on the use of beta blockers for septic cardiomyopathy and their influence on proinflammatory cytokines are warranted.

A comparison of the combination of epinephrine and vasopressin with lipid emulsion in a porcine model of asphyxial cardiac arrest after intravenous injection of bupivacaine.

BACKGROUND: In a porcine model, we compared the effect of the combination of vasopressin/epinephrine with that of a lipid emulsion on survival after bupivacaine-induced cardiac arrest. METHODS: After administration of 5 mg/kg of a 0.5% bupivacaine solution i.v., ventilation was interrupted for 2 +/- 0.5 (mean +/- SD) min until asystole occurred. Cardiopulmonary resuscitation (CPR) was initiated after 1 min of untreated cardiac arrest. After 2 min of CPR, 10 animals received, every 5 min, either vasopressin combined with epinephrine or 4 mL/kg of a 20% lipid emulsion. Three minutes after each drug administration, up to three countershocks (4, 4, and 6 J/kg) were administered; all subsequent shocks with 6 J/kg. Blood for determination of the plasma bupivacaine concentration was drawn throughout the experiment. RESULTS: In the vasopressor group, all five pigs survived, whereas none of five pigs in the lipid group had restoration of spontaneous circulation (P < 0.01). There was no significant difference between groups in the plasma concentration of total bupivacaine. CONCLUSION: In this model of a bupivacaine-induced cardiac arrest, the vasopressor combination of vasopressin and epinephrine compared with lipid emulsion resulted in higher coronary perfusion pressure during CPR and survival rates.

Anesthesia and its allied disciplines in the developing world: a nationwide survey of the Republic of Zambia.

BACKGROUND: Many surgical interventions worldwide are performed in developing countries. To improve survival of acutely and critically ill patients in these countries, basic problems and demands of anesthesia care need to be identified. Using this survey, we evaluated the current status of anesthesia and its allied disciplines (intensive care medicine, emergency medicine, and pain therapy) in the Republic of Zambia. METHODS: Questionnaires were sent to 87 hospitals registered at the Zambian Ministry of Health as performing minor or major surgery. The questionnaire consisted of 111 questions grouped into five sections: general hospital information, anesthesia, intensive care, emergency medicine, and pain therapy. RESULTS: Sixty-eight questionnaires could be statistically evaluated (78%). The most common operations were obstetric/gynecological and abdominal surgical procedures. Dissociative ketamine anesthesia was the technique most often used for general anesthesia (50%). Endotracheal intubation was performed in 10% of patients undergoing general anesthesia. In most hospitals (78%), anesthesia was administered by nonphysicians. Only 5 of 68 hospitals (7%) reported having an intensive care unit, with 29 beds to serve the entire country. Anesthesiologists play almost no role in emergency medicine and pain therapy. CONCLUSIONS: Anesthesia in the Republic of Zambia is a highly under-developed and under-resourced medical specialty.

Endogenous vasopressin and copeptin response in multiple trauma patients.

Endogenous arginine vasopressin (AVP) levels in multiple trauma patients are unknown. Arginine vasopressin is considered to play an important role in severe hemorrhage. In this prospective study, 87 multiple trauma patients (Injury Severity Score >15) and 50 healthy volunteers were enrolled. On admission to the emergency department (ED), demographic, clinical, and laboratory data were documented, and blood was sampled for determination of AVP (radioimmunosassay) and copeptin, a stable fragment of the AVP precursor (immunoluminometric assay). In patients requiring intensive care unit (ICU) therapy, blood and data sampling were repeated at 4, 6, and 24 h after ED admission. Linear logistic and mixed-effects regression analyses were used for statistical analysis. On ED admission, AVP plasma concentrations (43.2 +/- 84.9 pM) were significantly increased when compared with controls (0.92 +/- 0.44 pM, P < 0.001). Plethysmographic oxygen saturation was the only parameter independently associated with AVP (regression coefficient, -0.126; 95% confidence interval, -0.237 to -0.014; P = 0.03). No correlation was observed between AVP and survival (P = 0.62), hemodynamic variables (systolic arterial pressure, P = 0.24; MAP, P = 0.59; diastolic arterial pressure, P = 0.74; central venous pressure, P = 0.36), or brain trauma (P = 0.46). In ICU patients, AVP decreased during the first 24 h (P < 0.001) and was independently associated with heart rate (P = 0.02) and blood glucose (P = 0.009). Copeptin concentrations were correlated with AVP (r2 = 0.718, P < 0.001). In conclusion, AVP was significantly increased in multiple trauma patients and seems to be an integral part of the neuroendocrine response to severe injury. In ICU patients, AVP decreased to moderately elevated levels within 24 h after ED admission.

Comparison of two dose regimens of arginine vasopressin in advanced vasodilatory shock.

OBJECTIVE: To evaluate the effects of two arginine vasopressin (AVP) dose regimens (0.033 vs. 0.067 IU/min) on treatment efficacy, hemodynamic response, prevalence of adverse events, and changes in laboratory variables. DESIGN: Retrospective, controlled study. PATIENTS: A total of 78 patients with vasodilatory shock (mean norepinephrine dosage, 1.07 microg.kg-1.min-1; 95% confidence interval, 0.82-1.56 microg.kg-1.min-1). INTERVENTIONS: Supplementary infusion of AVP at 0.033 (n = 39) and 0.067 IU/min (n = 39). MEASUREMENTS AND MAIN RESULTS: Cardiocirculatory, laboratory, and clinical variables were evaluated and compared between groups before and at 0.5, 1, 4, 12, 24, 48, and 72 hrs after initiation of AVP. Treatment efficacy was assessed by the increase in mean arterial blood pressure and the extent of norepinephrine reduction during the first 24 hrs of AVP therapy. Standard tests and a mixed-effects model were used for statistical analysis. Although the relative increase in mean arterial pressure was comparable between groups (0.033 vs. 0.067 IU/min: 16.8 +/- 18.4 vs. 21.4 +/- 14.9 mm Hg, p = .24), norepinephrine could be reduced significantly more often in patients receiving 0.067 IU/min. AVP at 0.067 IU/min resulted in a higher mean arterial pressure (p < .001), lower central venous pressure (p = .001), lower mean pulmonary arterial pressure (p = .04), and lower norepinephrine requirements (p < .001) during the 72-hr observation period. Increases in liver enzymes occurred more often in patients treated with 0.033 IU/min (71.8% vs. 28.2%, p < .001). The prevalence of a decrease in cardiac index (69.2% vs. 53.8%, p = .24), decrease in platelet count (94.8% vs. 84.6%, p = .26), and increase in total bilirubin (48.7% vs. 71.8%, p = .06) was not significantly different between groups. Bilirubin levels (3.1 +/- 3.4 vs. 5.2 +/- 5.5 mg/dL, p = .04) and base deficit (-7.2 +/- 4.3 vs. -3.9 +/- 5.9 mmol/L, p = .005) were lower and arterial lactate concentrations higher (76 +/- 67 vs. 46 +/- 38 mg/dL, p < .001) in patients receiving 0.033 IU/min. CONCLUSIONS: AVP dosages of 0.067 IU/min seem to be more effective to reverse cardiovascular failure in vasodilatory shock requiring high norepinephrine dosages than 0.033 IU/min.