Nine treatments of 1000 mL therapeutic phlebotomy in a subject with polycythemia: A case report.

Large-volume therapeutic phlebotomy is the mainstay of hemochromatosis treatment and offers an opportunity to investigate the hemodynamic changes during acute hypovolemia. An otherwise healthy 64-year-old male with hemochromatosis participated. On nine separate visits, 1000 mL therapeutic phlebotomy was performed. On one occasion, pre- and post-phlebotomy orthostatic challenge with 27° reverse Trendelenburg position was administered. Mean arterial pressure, heart rate, and stroke volume were measured continuously during the procedures. The patient's tolerance to the interventions was continuously evaluated. The procedures were well tolerated by the patient. Mean arterial pressure was maintained during hemorrhage and following phlebotomy in both supine and reverse Trendelenburg positions, primarily through an increase in heart rate and systemic vascular resistance. The present study found that 1000 mL therapeutic phlebotomy in a patient with hemochromatosis may be acceptably and safely used to model hemorrhage. The approach demonstrates high clinical applicability and ethically robustness in comparison with volunteer studies.

Carbon monoxide and cyanide gas poisoning in fires. / Forgiftning med karbonmonoksid og cyanidgass ved brann.

Acute poisoning caused by inhalation of carbon monoxide and other toxic substances is the primary cause of death in fires and may occur without signs of external injury. Life-threatening symptoms may arise immediately, as in cyanide poisoning, or over a longer period, as in carbon monoxide poisoning. Severe inhalation injury may also occur independently of systemic poisoning and should always be suspected in patients with soot on their face and in the respiratory tract, or hoarseness and wheezing.

Manual ventilation and open suction procedures contribute to negative pressures in a mechanical lung model.

INTRODUCTION: Removal of pulmonary secretions in mechanically ventilated patients usually requires suction with closed catheter systems or flexible bronchoscopes. Manual ventilation is occasionally performed during such procedures if clinicians suspect inadequate ventilation. Suctioning can also be performed with the ventilator entirely disconnected from the endotracheal tube (ETT). The aim of this study was to investigate if these two procedures generate negative airway pressures, which may contribute to atelectasis. METHODS: The effects of device insertion and suctioning in ETTs were examined in a mechanical lung model with a pressure transducer inserted distal to ETTs of 9 mm, 8 mm and 7 mm internal diameter (ID). A 16 Fr bronchoscope and 12, 14 and 16 Fr suction catheters were used at two different vacuum levels during manual ventilation and with the ETTs disconnected. RESULTS: During manual ventilation with ETTs of 9 mm, 8 mm and 7 mm ID, and bronchoscopic suctioning at moderate suction level, peak pressure (PPEAK) dropped from 23, 22 and 24.5 cm H2O to 16, 16 and 15 cm H2O, respectively. Maximum suction reduced PPEAK to 20, 17 and 11 cm H2O, respectively, and the end-expiratory pressure fell from 5, 5.5 and 4.5 cm H2O to -2, -6 and -17 cm H2O. Suctioning through disconnected ETTs (open suction procedure) gave negative model airway pressures throughout the duration of the procedures. CONCLUSIONS: Manual ventilation and open suction procedures induce negative end-expiratory pressure during endotracheal suctioning, which may have clinical implications in patients who need high PEEP (positive end-expiratory pressure).

Can ventilator settings reduce the negative effects of endotracheal suctioning? Investigations in a mechanical lung model.

BACKGROUND: The insertion of suction devices through endotracheal tubes (ETTs) increases airway resistance and the subsequent suctioning may reduce airway pressures and facilitate atelectasis. The aim of this study was to investigate how airway pressures and tidal volumes change when different combinations of suction equipment and ETT sizes are used, and to what extent unfavorable effects can be ameliorated by choice of ventilator settings. METHODS: A mechanical ventilator was connected to a lung model by ETTs of 9 mm, 8 mm or 7 mm internal diameter (ID) with a pressure transducer inserted distal to the ETT. The effects of suction procedures with bronchoscope and closed catheter systems were investigated during pressure controlled ventilation (PCV) and volume controlled ventilation (VCV). In each mode, the effects of changes in inspiration:expiration (I:E) ratio, trigger sensitivity and suction pressure were examined. RESULTS: The variables that contributed most to negative model airway pressures and loss of tidal volume during suctioning were (in descending order); 1) Small-size ETTs (7-8 mm ID) combined with large diameter suction devices (14-16 Fr); 2) inverse I:E ratio ventilation (in VCV); 3) negative ventilator trigger sensitivity; and 4) strong suction pressure. The pressure changes observed distal to the ETTs were not identical to those detected by the ventilator. CONCLUSIONS: Negative model airway pressure was induced by suctioning through small-size ETTs. The most extreme pressure and volume changes were ameliorated when conventional ventilator settings were used, such as PCV mode with short inspiration time and a trigger function sensitive to flow changes.

Intramedullary nailing of femoral shaft fractures in polytraumatized patients. a longitudinal, prospective and observational study of the procedure-related impact on cardiopulmonary- and inflammatory responses.

BACKGROUND: Early intramedullary nailing (IMN) of long bone fractures in severely injured patients has been evaluated as beneficial, but has also been associated with increased inflammation, multi organ failure (MOF) and morbidity. This study was initiated to evaluate the impact of primary femoral IMN on coagulation-, fibrinolysis-, inflammatory- and cardiopulmonary responses in polytraumatized patients. METHODS: Twelve adult polytraumatized patients with femoral shaft fractures were included. Serial blood samples were collected to evaluate coagulation-, fibrinolytic-, and cytokine activation in arterial blood. A flow-directed pulmonary artery (PA) catheter was inserted prior to IMN. Cardiopulmonary function parameters were recorded peri- and postoperatively. The clinical course of the patients and complications were monitored and recorded daily. RESULTS: Mean Injury Severity Score (ISS) was 31 ± 2.6. No procedure-related effect of the primary IMN on coagulation- and fibrinolysis activation was evident. Tumor necrosis factor alpha (TNF-α) increased significantly from 6 hours post procedure to peak levels on the third postoperative day. Interleukin-6 (IL-6) increased from the first to the third postoperative day. Interleukin-10 (IL-10) peaked on the first postoperative day. A procedure-related transient hemodynamic response was observed on indexed pulmonary vascular resistance (PVRI) two hours post procedure. 11/12 patients developed systemic inflammatory response syndrome (SIRS), 7/12 pneumonia, 3/12 acute lung injury (ALI), 3/12 adult respiratory distress syndrome (ARDS), 3/12 sepsis, 0/12 wound infection. CONCLUSION: In the polytraumatized patients with femoral shaft fractures operated with primary IMN we observed a substantial response related to the initial trauma. We could not demonstrate any major additional IMN-related impact on the inflammatory responses or on the cardiopulmonary function parameters. These results have to be interpreted carefully due to the relatively few patients included. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00981877.

The acidosis-induced right shift of the HbO2 dissociation curve is maintained during erythrocyte storage.

BACKGROUND AND OBJECTIVES: In fresh blood, tissue hypoxia increases microcirculatory acidosis, which enhances erythrocyte O(2) unloading and increases the amount of available O(2). Storage of erythrocytes increases the HbO(2) affinity and reduces O(2) unloading. We examined the development of the affinity change during a period of 5 weeks of storage by present blood bank standards, and investigated to what extent acidosis offsets the affinity change. MATERIALS AND METHODS: Blood from volunteer donors was processed and stored as erythrocyte concentrates (EC). At 2-5 day intervals, EC were drawn from the bags and suspended in plasma and crystalloids to an Hb ≈ 10 g/dL. The suspensions were adjusted to give a pH of 7.40, 7.10, 6.80 or 6.30 and equilibrated with different gas mixtures to SO(2) 0, 25, 50, 75 and 100%. Measurements of the PO(2)/SO(2) pairs at each pH were used to calculate the position of the HbO(2) curve and its P(50) value. RESULTS: A significant leftward shift in the HbO(2) curve was established after 1 week of storage; after 2.5 weeks only minor further changes were observed. Acidification right-shifted the HbO(2) curve, after 2.5 weeks of storage the curve at pH 7.10 was similar to that for fresh blood at pH 7.40. Calculations of extractable O(2) showed that the left-shifted HbO(2) curve of stored EC could be advantageous at a low arterial PO(2). CONCLUSIONS: The rightward shift of the HbO(2) curve due to acidosis is well maintained in stored erythrocytes, a moderate pH decrease offsets the storage-induced increased HbO(2) affinity.

Coagulation, fibrinolysis and cytokine responses to intramedullary nailing of the femur: an experimental study in pigs comparing traditional reaming and reaming with a one-step reamer-irrigator-aspirator system.

INTRODUCTION: Operations in trauma patients represent a second insult and the extent of the surgical procedures influences the magnitude of the inflammatory response. Our hypothesis was that a reamer-irrigator-aspirator (RIA) system would cause a lesser inflammatory response than traditional reaming (TR). MATERIALS AND METHODS: Coagulation, fibrinolysis and cytokine responses were studied in Norwegian landrace pigs during and after intramedullary nailing (IMN) with two different reaming systems using ELISA and chromogenic peptide substrate assays. The TR (n=8) and the RIA (n=7) reaming systems were compared to a control group (n=7). The animals were followed for 72 h. Arterial, mixed venous and femoral vein blood were withdrawn simultaneously peroperatively and until 2 h after the nail was inserted for demonstration of local, pulmonary and systemic activation of the cascade systems. At 6 h, 24 h, 48 h and 72 h postoperatively arterial blood samples were withdrawn. RESULTS: Significantly procedure-related increased levels were found for thrombin-antithrombin (TAT) and tissue plasminogen activator (t-PA) in the TR group and TAT in the RIA group. The local and the pulmonary activation of coagulation and fibrinolysis were more pronounced in the TR than in the RIA group, the difference reached significance for plasminogen activator inhibitor-1 (PAI-1) (arterial blood). The cytokine response, mainly represented by IL-6 increase, was more pronounced in the TR than the RIA group, and was significant for IL-6 in femoral vein blood. The arterial levels of IL-6 exceeded the mixed venous levels indicating an additional pulmonary activation of IL-6. Two animals in the TR group, who died of pulmonary embolism (PE) prior to planned study end point, had a more pronounced response compared to the rest of the TR group. CONCLUSION: A procedure-related coagulation and fibrinolytic response was demonstrated in both reaming groups, with more pronounced response in the TR than in the RIA group. Elevated levels of cytokines were demonstrated related to reaming and nailing, with significantly higher IL-6 levels in the TR than in the RIA group.

Intravasation of bone marrow content. Can its magnitude and effects be modulated by low pressure reaming in a porcine model?

INTRODUCTION: Intramedullary orthopaedic procedures may increase the intramedullary pressure (IMP) and thereby cause intravasation of bone marrow contents. In recent studies by the authors the reamer-irrigator-aspirator (RIA) has been demonstrated to reduce IMP and coagulation-, fibrinolysis- and cytokine responses, but did not prove any significant difference in cardiopulmonary function parameters or numbers of emboli when compared to a traditional reaming (TR) system. The correlations between IMP increase, regardless type of reamer, and inflammatory- and coagulation responses, pulmonary embolization, and cardiopulmonary alterations have, however, not previously been analyzed in this material. Our hypothesis was that a lower IMP would result in reduced occurrence of pulmonary embolization, reduced inflammatory-and coagulation responses, as well as reduced cardiopulmonary alterations. MATERIALS AND METHODS: Twenty-eight young Norwegian landrace pigs were exposed to femoral intramedullary reaming, with either the TR (n = 10) or the RIA (n = 10) system, or used as controls (n = 8). IMP was recorded during reaming and nailing. Serial blood samples for demonstration of coagulation-, fibrinolysis-, and cytokine activation were withdrawn peroperatively and until 72 hours post nail insertion. Circulatory and pulmonary effects were monitored peroperatively and until two hours postoperatively. The animals were sacrificed 72 hours post nail insertion and lung tissue biopsies were harvested and examined for lung emboli. RESULTS AND CONCLUSIONS: A strong correlation between increased IMP and increased coagulation-and cytokine responses was found. The number of emboli was not significantly correlated to IMP, but was strongly correlated to changes in the coagulation- and cytokine responses. No clinical relevant correlations were observed between increased IMP or numbers of lung emboli and changes in hemodynamic- or pulmonary function parameters. A correlation between coagulation activation and cytokine activation was observed. This study confirms the connection between increased IMP, increased coagulation activation and the magnitude of pulmonary emboli in a model evaluating the effects of intramedullary reaming of intact pig femora. In this model, the lowering of IMP during reaming, as obtained with RIA, reduced the magnitude of and the effects of bone marrow extravasation.

Cardiopulmonary response to reamed intramedullary nailing of the femur comparing traditional reaming with a one-step reamer-irrigator-aspirator reaming system: an experimental study in pigs.

BACKGROUND: Intramedullary reaming and nailing increases intramedullary pressure. This may cause intravasation of bone marrow contents, leading to bone marrow embolization and altered cardiopulmonary function. Possible beneficial effects of attenuation of the intramedullary pressure increase by the use of a reamer-irrigator-aspirator (RIA) system were studied with the hypothesis that the RIA technique would cause lower numbers of pulmonary embolisms (PEs) and lesser cardiopulmonary affection than traditional reaming (TR). MATERIAL AND METHODS: Intramedullary reaming and nailing was performed in intact femora of young Norwegian landrace pigs using either a standard intramedullary nailing technique (n = 8) or a RIA technique (n = 7). The hemodynamic and pulmonary effects were investigated during the reaming and nailing procedure and for 2 hours postoperatively. The animals were killed after 72 hours, and the lung/carcass weight ratio and the numbers of PEs were investigated. RESULTS AND CONCLUSION: The pattern of the procedure-related hemodynamic and pulmonary effects did not differ significantly between the RIA and the TR groups. The RIA group had lower numbers (ns) of embolisms per square centimeter lung area than the TR group. After reaming with the TR device, two animals died of PEs, the first postoperative day. The patients with femoral shaft fracture and additional cardiopulmonary injury or preexisting reduced cardiopulmonary function, however, need special attention, and the use of RIA may, in these cases, represent a better operative alternative with a lesser operative burden.

[Acute respiratory failure concomitant with serious disease or injury]. / Akutt respirasjonssvikt ved alvorlig sykdom og skade.

BACKGROUND: Acute respiratory failure has an annual incidence of 20-75/100,000 and is the most common reason for admittance to an intensive care unit. A common cause is acute inflammatory changes in lung tissue. The article reviews clinical, etiological, pathophysiological and therapeutic aspects of acute respiratory failure, with an emphasis on failure secondary to proinflammatory processes. MATERIAL AND METHODS: This paper is not based on a comprehensive literature review, but on the clinical and scientific experience of the author, literature from a private archive and a limited Medline search. RESULTS: Acute respiratory failure can be precipitated by agents and/or trauma that damage the lungs directly. Serious infections and tissue damage located in other parts of the body can also cause respiratory failure. In these cases, the blood transports activated blood cells and proinflammatory agents to the lungs where they induce secondary tissue inflammation. The resulting respiratory failure is often serious. Mortality is in the range 30-50 %. INTERPRETATION: No specific treatment is available for secondary tissue inflammation; it usually resolves when the precipitating injuries or disease processes are healed. Positive pressure ventilation can prevent serious hypoxemia from causing additional damage to affected tissue. With modern treatment in an intensive care unit only 10-15 % of the deaths are caused by the respiratory failure per se, most deaths are caused by failure of several additional organs (multiorgan failure).