Medical management after indoor fires: a review.

UNLABELLED: Fires involving mass burn casualties require extreme efforts and flexibility from the regular health care system. The café fire in Volendam, which occurred shortly after midnight on the first of January 2001, resulted in the worst indoor mass burns incident in Dutch history. During the extensive medical evaluation of this disaster, it became obvious that information on similar incidents is relatively scarce in the literature. This article systematically reviews the existing information in the medical literature on indoor fires and provides findings and knowledge used in the evaluation of the medical management after indoor fires and for future mass burn casualty preparedness, mitigation and response. METHODS: A literature review was undertaken for burn disasters with characteristics similar to the indoor Volendam fire disaster. In all fires, the following aspects were investigated: characteristics of the fire; the initial emergency response; triage and on-site treatment; primary and secondary distribution; hospital admission; severity of the sustained injuries and mortality. RESULTS: A total of nine similar indoor fires were selected. The number of people involved was reported in seven fires (range 137-6000). All reports provided the mortality rate (range 1.4% to over 50%). Data regarding the emergency response could be collected in half of the studies. On-scene triage was performed in five fires. The number of hospitals participating in the primary distribution ranged from 1 to 19. Except for the Volendam fire, all patients were primarily distributed to general hospitals. CONCLUSION: Characteristics of indoor fires, which are relevant for disaster preparedness, mitigation and response are not frequently reported in medical literature. The current articles on indoor fires, mainly report on numbers of casualties and the mortality. Limited data are available to provide insight in the characteristics of management and medical treatment and to come up with suggestions for improvement of future burn incidents management. The evaluation of disasters should be based on uniform methods and structured reports and effective record keeping is essential to achieve this.

The café fire on New Year's Eve in Volendam, the Netherlands: description of events.

AIM OF STUDY: The café fire at Volendam occurred shortly after midnight on the first of January 2001 and resulted in one of the worst mass burn incidents in recent Dutch history. The aim of this study was to provide insight into medical and organisational requirements of a major burns incident. METHODS: Shortly after the fire, two university hospitals and a burn center in the region of the accident developed a plan for evaluation of medical care given during and after this major burn incident. A multidisciplinary research group investigated the management of victims at the scene, in the emergency departments (ED) and during admission in the hospitals. All 245 casualties were included in this study. RESULTS: A brief severe fire occurred in a crowded cafe with around 350 young visitors on a small embankment of a relatively isolated town, resulting in a unusually high number of severely injured burn victims. Four died immediately. The ensuing rescue effort was hampered by poor access and chaotic circumstances. At the scene of the incident, mobile medical teams ensured orderly transport and treatment priority for the injured. There were 245 victims with a median total body surface area burned of 12%. Inhalation injury was present in 96 patients. A total of 182 victims were admitted, with 112 to intensive care. Ten patients died in the hospital. Seventy-eight patients were secondarily transported, many to specialised centers in the Netherlands and abroad. In total, 36 hospitals in three countries participated. CONCLUSION: An incident with high numbers of burn victims poses a challenge to any health care system. The difficult circumstances at the site demonstrated the need for robust organisational structures. The primary and secondary distribution of patients required coordination, general hospitals were able to provide initial medical care to these major burn casualties.

Critical hematocrit in intestinal tissue oxygenation during severe normovolemic hemodilution.

BACKGROUND: A critical point in oxygen supply for microvascular oxygenation during normovolemic hemodilution has not been identified. The relation between organ microvascular oxygen partial pressure (microPO2) and organ oxygen consumption (VO2) during a decreasing oxygen delivery (DO2) is not well understood. The present study was designed to determine the systemic hematocrit and organ DO2 values below which organ microPO2 and VO2 cannot be preserved by regulatory mechanisms during normovolemic hemodilution. METHODS: Eighteen male Wistar rats were randomized between an experimental group (n = 12), in which normovolemic hemodilution was performed with pasteurized protein solution (PPS), and a control group (n = 6). Systemic hemodynamic and intestinal oxygenation parameters were monitored. Intestinal microPO2 was measured using the oxygen-dependent quenching of palladium-porphyrin phosphorescence. RESULTS: Baseline values in hemodilution and control group were similar. Hemodilution decreased hematocrit to 6.2 +/- 0.8% (mean +/- SD). Constant central venous pressure measurements suggested maintenance of isovolemia. Despite an increasing mesenteric blood flow, intestinal DO2 decreased immediately. Initially, microPO2 was preserved, whereas mesenteric venous PO2 (P(mv)O2) decreased; below a hematocrit of 15%, microPO2 decreased significantly below P(mv)O2. Critical DO2 was 1.5 +/- 0.5 ml x kg(-1) x min(-1) for VO2, and 1.6 +/- 0.5 ml x kg(-1) x min(-1) for microPO2. Critical hematocrit values for VO2 and microPO2 were 15.8 +/- 4.6% and 16.0 +/- 3.5%, respectively. CONCLUSIONS: Intestinal microPO2 and VO2 were limited by a critical decrease in DO2 and hematocrit at the same time. Beyond these critical points not only shunting of oxygen from the microcirculation could be demonstrated, but also a significant correlation between intestinal microPO2 and VO2.

The effect of the transfusion of stored RBCs on intestinal microvascular oxygenation in the rat.

BACKGROUND: Although it is known that the transfusion of stored RBCs does not always improve tissue O(2) consumption under conditions of limited tissue oxygenation, the efficiency of O(2) delivery to the microcirculation by stored RBCs has never been determined. STUDY DESIGN AND METHODS: In a rat hemorrhagic shock model, the effects of resuscitation with fresh or 28-day-old RBCs stored in CPD plasma, saline-adenine-glucose-mannitol, and CPDA-1 plasma were investigated. Systemic hemodynamic and intestinal oxygenation measures were monitored. Intestinal microvascular PO(2) was determined with the O(2)-dependent quenching of palladium-porphyrin phosphorescence, and the RBC deformability was measured with a Laser-assisted optic rotational cell analyzer. RESULTS: Hemodynamic and oxygenation measures were significantly decreased during hemorrhagic shock. Intestinal oxygen consumption and mesenteric venous pO(2) were restored with the transfusion of both fresh and stored RBCs, except for CPD-stored RBCs. The intestinal microvascular pO(2) improved only with the transfusion of fresh RBCs. Deformability of the stored RBCs was significantly decreased. CONCLUSION: In contrast to that of fresh RBCs, the transfusion of stored RBCs did not restore the microcirculatory oxygenation, possibly because of impaired O(2) unloading, but, except for CPD-stored RBCs, the storage-induced changes were not enough to impair intestinal VO(2) and mesenteric venous pO(2).

Heparin-protamine complexes and C-reactive protein induce activation of the classical complement pathway: studies in patients undergoing cardiac surgery and in vitro.

The administration of protamine to patients undergoing cardiopulmonary bypass (CPB) to neutralize heparin and to reduce the risk of bleeding, induces activation of the classical complement pathway mainly by heparin-protamine complexes. We investigated whether C-reactive protein (CRP) contributes to protamine-induced complement activation. In 24 patients during myocardial revascularization, we measured complement, CRP, and complement-CRP complexes, reflecting CRP-mediated complement activation in vivo. We also incubated plasma from healthy volunteers and patients with heparin and protamine in vitro to study CRP-mediated complement activation. During CPB, CRP levels remained unchanged while C3 activation products increased. C4 activation occurred after protamine administration. CRP-complement complexes increased at the end of CPB and upon protamine administration. Incubation of plasma with heparin and protamine in vitro generated complement-CRP complexes, which was blocked by phosphorylcholine and stimulated by exogenous CRP. C4d-CRP complex formation after protamine administration correlated clinically with the incidence of postoperative arrhythmia. Protamine administration during cardiac surgery induces complement activation which in part is CRP-dependent, and correlates with postoperative arrhythmia.

Preservation of intestinal microvascular Po2 during normovolemic hemodilution in a rat model.

The effect of hemodilution on the intestinal microcirculatory oxygenation is not clear. The aim of this study was to determine the effect of moderate normovolemic hemodilution on intestinal microvascular partial oxygen pressure (Po2) and its relation to the mesenteric venous Po2 (Pmvo2). Normovolemic hemodilution was performed in 13 anesthetized male Wistar rats. Systemic hemodynamic and intestinal oxygenation parameters were monitored. Intestinal microvascular Po2 was measured by using the oxygen-dependent quenching of palladium-porphyrin phosphorescence. Hemodilution decreased systemic hematocrit from 45.0% +/- 0.1% (average +/- SEM) to 24.6% +/- 1.6%. The mesenteric blood flow did not change from baseline values, resulting in a linear decrease in intestinal oxygen delivery (from 2.77 +/- 0.15 to 1.42 +/- 0.11 mLxkg(-1)xmin(-1)). The intestinal oxygen extraction ratio increased significantly from 24% +/- 1% to 42% +/- 4%. Pmvo2 decreased significantly (from 57 +/- 2 to 41 +/- 2 mm Hg), but intestinal oxygen consumption and microvascular Po2 remained unaffected. As a result, the difference between microvascular Po2 and Pmvo2 increased significantly during hemodilution. Intestinal microvascular Po2 and oxygen consumption were well preserved during moderate normovolemic hemodilution. These results might be explained by the notion of others that hemodilution induces recruitment of capillaries, resulting in redistribution of the intestinal blood flow in favor of the microcirculation, which allows a more efficient extraction of oxygen. These findings further indicate that the use of venous Po2 values as indicators of microvascular oxygenation may be misleading.

Low-volume resuscitation with a hemoglobin-based oxygen carrier after hemorrhage improves gut microvascular oxygenation in swine.

Using palladium-porphyrin quenching of phosphorescence, we investigated the influence of diaspirin cross-linked hemoglobin (DCLHb) on gut microvascular oxygen pressure (microPO2) in anesthetized pigs. Values of gut microPO2 were studied in correlation with regional intestinal as well as global metabolic and circulatory parameters. A controlled hemorrhagic shock (blood withdrawal of 40 mL/kg) was followed by resuscitation with either a combination of lactated Ringer's solution (75 mL/kg) and modified gelatin (15 mL/kg)(lactR/Gel) or 10% DCLHb (5 mL/kg). After resuscitation, gut microPO2 was similarly improved in the lactR/Gel group (from 25 +/- 10 mm Hg to 53 +/- 8 mm Hg) and the DCLHb group (from 23 +/- 9 mm Hg to 46 +/- 6 mm Hg), which was associated with increased gut oxygen delivery. However, the improvement after resuscitation with DCLHb was sustained for longer periods of time (75 vs 30 min). Mesenteric venous PO2 was increased after resuscitation with lactated Ringer's solution and modified gelatin but not with DCLHb, which was associated with an increased gut oxygen consumption in the latter group. We conclude that measurement of microPO2 by the palladium-porphyrin phosphorescence technique revealed DCLHb to be an effective carrier of oxygen to the microcirculation of the gut. Also, this effect can be achieved with a lower volume than is currently used in resuscitation procedures.

Activation of the complement system during and after cardiopulmonary bypass surgery: postsurgery activation involves C-reactive protein and is associated with postoperative arrhythmia.

BACKGROUND: Complement activation during cardiopulmonary bypass (CPB) surgery is considered to result from interaction of blood with the extracorporeal circuit. We investigated whether additional mechanisms may contribute to complement activation during and after CPB and, in particular, focused on a possible role of the acute-phase protein C-reactive protein (CRP). METHODS AND RESULTS: In 19 patients enrolled for myocardial revascularization, perioperative and postoperative levels of complement activation products, interleukin-6 (IL-6), CRP, and complement-CRP complexes, reflecting CRP-mediated complement activation in vivo, were measured and related to clinical symptoms. A biphasic activation of complement was observed. The ratio between the areas under the curve of perioperative and postoperative C3b/c and C4b/c were 3:2 and 1:46, respectively. IL-6 levels reached a maximum at 6 hours post-surgery. CRP levels peaked on the second postoperative day. Each complement-CRP complex had peak levels on the second or third postoperative day. By multivariate analysis, maximum levels of CRP on the second postoperative day were mainly explained by C4b/c levels after protamine administration, leukocyte count on the second postoperative day, and preoperative levels of CRP. Peak levels of C4b/c after protamine administration (P=.0073) and on the second postoperative day correlated with the occurrence of arrhythmia on the same day (P=.0065). CONCLUSIONS: Cardiac surgery with CPB causes a biphasic complement activation. The first phase occurs during CPB and results from the interaction of blood with the extracorporeal circuit. The second phase, which occurs during the first 5 days after surgery, involves CRP, is related to baseline CRP levels, and is associated with clinical symptoms such as arrhythmia.

Birth weight, growth, and blood pressure: an annual follow-up study of children aged 5 through 21 years.

Associations between birth weight and blood pressure have been found in children and adults. In this longitudinal study, the objective was to assess the relation between birth weight and blood pressure level and the change in blood pressure from childhood and young adolescence into adulthood. A cohort of 483 children from a middle-class community in the town of Zoetermeer in the Netherlands had annual measurements of blood pressure during an average follow-up period of 14 years. For 330 of these participants, initially aged 5 through 21 years, birth weight data were collected, which were related to blood pressure level and blood pressure change. An inverse association between birth weight and systolic blood pressure was found, with adjustment for current body height and weight, sex, and use of alcohol, cigarettes, and oral contraceptives. This inverse association was found for the total follow-up in 5- to 37- year-olds (regression coefficient: -2.4 mm Hg/kg; 95% confidence interval: -3.9 to -1.0, as well as in most individual age groups: 5 through 9 years (-0.6 mm Hg/kg, -3.2 to 2.0); 10 through 14 years (-2.5 mm Hg/kg, -4.7 to -0.4); 15 through 19 years (-3.1 mm Hg/kg, -4.9 to -1.2); 20 through 24 years (-2.7 mm Hg/kg, -4.6 to -0.9); 25 through 29 years (-2.0 mm Hg/kg, -3.9 to -0.01); and 30 through 37 years (-1.9 mm Hg/kg, -4.6 to 0.7). For diastolic blood pressure, there appeared to be an inverse association with birth weight in the age group of 30 through 37 years, both unadjusted (-2.0 mm Hg/kg, -4.6 to 0.5) and adjusted for risk factors other than sex (-2.3 mm Hg/kg, -4.7 to 0.1), although these findings were of borderline statistical significance. The results were independent of gestational age and were similar in the group of subjects with low birth weight but normal gestational age (-2.7 mm Hg/kg, -4.3 to -1.0). In relation to systolic blood pressure, birth weight showed a significant interaction with body mass index (regression coefficient, 0.02; SE=0.01; P=.05). There was no relation between birth weight and change in systolic or diastolic blood pressure with age. Our longitudinal study shows that birth weight is consistently inversely associated with systolic blood pressure level from childhood to young adulthood and with diastolic blood pressure in young adulthood. Birth weight is not related to change of blood pressure with increasing age. Low birth weight in combination with high current body mass index seems to be of particular importance in the development of high blood pressure.

Influence of motivation of care providers on the incidence of postoperative hypoxaemia in the recovery room.

We have studied the influence of motivation of care providers on the incidence and duration of postoperative hypoxaemia in the recovery room. In a prospective, switch-back designed cohort study, we have compared the incidence of low pulse oximeter saturation values (SpO2) during pre-intervention, intervention and post-intervention phases. Low SpO2 values were classified as either hypoxaemia (SpO2 < or = 90%, minimum duration 1 min) or artefact. Pulse oximetry trend data from 1350 patients, 450 in each group, were analysed. During the intervention phase, motivation was increased by adding an explicit instruction to prevent and treat low SpO2 values and making personnel aware that they were being studied (Hawthorne effect). The incidence of hypoxaemia decreased significantly from 17.8% during the pre-intervention phase to 11.6% during the intervention phase (relative risk (RR) 0.65, 95% confidence interval (CI) 0.47-0.90; P < 0.01). The incidence of severe hypoxaemia (SpO2 < or = 85%, 1 min) decreased from 7.8% to 3.3% (RR 0.43, CI 0.24-0.76; P < 0.01). The number of patients who had severe hypoxaemia for more than 5 min decreased from 13 to 1 (RR 0.08, CI 0.02-0.36; P < 0.01). In the post-intervention period, the incidence of hypoxaemia returned to pre-intervention values. The results of this study suggest that motivation of care providers to prevent and treat low SpO2 is an important determinant of postoperative hypoxaemia in the recovery room.

A pilot study of the effects of a perflubron emulsion, AF 0104, on mixed venous oxygen tension in anesthetized surgical patients.

A pilot study of a perfluorochemical (PFC) emulsion was undertaken to determine whether administration of a perflubron emulsion could result in measurable changes in mixed venous oxygen tension. Seven adult surgical patients received a 0.9-g PFC/kg intravenous dose of perflubron emulsion after acute normovolemic hemodilution (ANH). Hemodynamic and oxygen transport data were collected before and after ANH, immediately after PFC infusion, and at approximate 15-min intervals throughout the surgical period. There were no clinically significant hemodynamic changes associated with the administration of the PFC emulsion. There was a significant increase in mixed venous oxygen tension (PVO2) after the PFC infusion, while cardiac output and oxygen consumption were unchanged. As surgery progressed, the hemoglobin concentration decreased with ongoing blood loss while PVO2 values remained at or above predosing levels. Peak perflubron blood levels were 0.8 g/dL immediately postinfusion, and approximately 0.3 g/dL at 1 h. This pilot study demonstrates that administration of perflubron emulsion results in measurable changes in mixed venous oxygen tension during intraoperative ANH.

Systemic haemodynamics and oxygenation during haemodilution in children.

Transfusion of homologous blood should be avoided when possible, and one technique that diminishes perioperative requirement for donor blood is haemodilution. In children its effects on systemic haemodynamics and systemic oxygenation have not been reported. Six children aged 4-12 yr were anaesthetised for major surgery and blood was withdrawn to reduce packed cell volume to 25%. Cardiac index increased from 3.1 (SD 0.5) L min-1 m-2 at baseline to 4.4 (0.5) L min-1 m-2 at the end of surgery, when packed cell volume was 16 (1)%; this change, compensating for the decline in oxygen carrying capacity, was associated with a fall in systemic vascular resistance and a rise in stroke volume. Oxygen extraction from haemoglobin rose from 0.22 (0.05) to 0.33 (0.06). Perioperative blood loss was 40% of circulating blood volume; however, owing to reinfusion of autologous blood (and use of a cell saver in three patients), the haemoglobin one day after operation was only 19% lower than preoperatively (9.9 [1.5] vs 12.5 [2.5] g/dL). In this study, children seemed at least as able as adults to compensate for the effects of haemodilution, which allowed major surgery without transfusion of homologous blood.

Transesophageal echocardiographic monitoring of preoperative acute hypervolemic hemodilution.

BACKGROUND: Preoperative acute hypervolemic hemodilution is used in anesthesia to reduce the loss of blood cells during intraoperative bleeding. Indications for use of the technique might be broadened if it can be shown to be safe in older as well as younger patients. Few data are available describing heart function in humans subjected to hypervolemic hemodilution. METHODS: Nineteen anesthetized Jehovah's Witnesses (ages 22-70 yr) without evidence of heart disease had hypervolemic hemodilution before surgery in three stages, each consisting of an infusion of 500 ml dextran 40 (50 g/l) and 500 ml Ringer's lactate over a 10-min period. After each stage, the size and function of the left ventricle were recorded by transesophageal cross-sectional echocardiography in the short-axis view. Simultaneously heart rate, arterial blood pressure, pulmonary arterial and wedge pressures and cardiac output were recorded, to compare the echocardiographic and hemodynamic data. RESULTS: No complications occurred. Hypervolemic hemodilution resulted in an increased cardiac output by increasing the stroke volume from 48 ml in basal conditions to 67, 71, and 72 ml over the three stages, whereas heart rate did not increase. There was an initial increase in end-diastolic volume of the left ventricle, as assessed from the cross-sectional end-diastolic area from 12.9 to 15.5, 16.6, and 16.9 cm2 followed by a decrease in the in cross-sectional end-systolic area from 6.3 to 6.8, 6.0, and 5.7 cm2. The increase in wedge pressures (from 5.9 to 12.4, 17.9, and 22.6 mmHg) did not lead to progressive cardiac dilation. There was a curvilinear relation between wedge pressure and cross-sectional end-diastolic area. Stroke volume did not decrease, nor did cross-sectional end-systolic area increase; instead, a decrease in end-systolic area was a common observation. CONCLUSIONS: The described regimen of acute hypervolemic hemodilution is well tolerated during anesthesia by patients without heart disease and does not lead to cardiac failure. It leads to an increase in stroke volume that is generated initially from an increase in end-diastolic volume, followed in many patients by a decrease in end-systolic volume, the mechanism of which is as yet unclear.

Catecholamines and regional hemodynamics during isovolemic hemodilution in anesthetized pigs.

The effects of stepwise isovolemic hemodilution on systemic and regional hemodynamics, oxygen flux, and circulating catecholamines were studied in six pigs anesthetized with midazolam and fentanyl. Reduction of the hematocrit from 28 to 9% resulted in doubling of the cardiac output, mainly due to an increase in stroke volume. Regional blood flows, measured using the radioactive microsphere technique, showed an increase in blood flow to all organs except liver (hepatic artery fraction) and adrenals, with a redistribution of cardiac output in favor of heart and brain (increase in blood flow 420 and 170%, respectively). Oxygen flux to most organs did not decrease until hematocrit decreased to 9%, while total body oxygen consumption was well maintained. Left ventricular oxygen consumption increased, but because left ventricular blood flow also increased, left ventricular extraction ratio did not increase. Circulating catecholamines did not play any role in these regulatory mechanisms.