Search PubMed⌕ Search

Biomedical subjects

H Imanaka

Publications and source records attributed to H Imanaka.

At least 19 recordsLinked to original sources
PubMed2001

Ventilator-induced lung injury is associated with neutrophil infiltration, macrophage activation, and TGF-beta 1 mRNA upregulation in rat lungs.

Activated neutrophils contribute to the development of ventilator-induced lung injury (VILI) caused by high-pressure mechanical ventilation. However, exact cellular and molecular mechanisms have not been conclusively studied. Our investigation aimed to examine expression of adhesion molecules by both neutrophils and macrophages in lung lavage fluids of rats with VILI. Further, involvement of proinflammatory (tumor necrosis factor-alpha) and profibrogenetic (transforming growth factor-beta 1) mediators was analyzed at mRNA level in lung tissue. Wistar rats were ventilated by high pressure (45 cm H(2)O of peak inspiratory pressure, n = 23) or low pressure (7 cm H(2)O, n = 13) with 0 positive end-expiratory pressure. After 40 min of comparative ventilation, lung lavage was performed in 20 rats from the experimental group and 10 from the control for immunofluorescence analysis with anti-Mac-1 and anti-ICAM-1 monoclonal antibodies. The lung tissues from remaining rats were subjected to pathological and reverse transcription-polymerase chain reaction examinations. Although there was no significant change of PaO(2) in the low-pressure group, PaO(2) was decreased in the high-pressure group. The high-pressure group also had greater neutrophil infiltration into alveolar spaces, upregulation of CD54 and CD11b on alveolar macrophages, and more transforming growth factor-beta 1 mRNA in lung tissues. Tumor necrosis factor-alpha was not involved in the pathogenesis of the severe VILI observed. Histologic findings also demonstrated more infiltrating neutrophils, destructive change of the alveolar wall, and deposition of matrix in the high-pressure group. These results suggest that a series of proinflammatory reactions and profibrogenetic process may be involved in the course of VILI.

Animals↗
PubMed2001

Effect of synchronized intermittent mandatory ventilation on respiratory workload in infants after cardiac surgery.

BACKGROUND: Synchronized intermittent mandatory ventilation (SIMV) is commonly used in infants and adults. However, few investigations have examined how SIMV reduces respiratory workload in infants. The authors evaluated how infants' changing respiratory patterns when reducing SIMV rate increased respiratory load. The authors also investigated whether SIMV reduces infant respiratory workload in proportion to the rate of mandatory breaths and which rate of SIMV provides respiratory workloads similar to those after tracheal extubation. METHODS: When 11 post-cardiac surgery infants aged 2-11 months were to be weaned with SIMV, the authors randomly applied five levels of mandatory breathing: 0, 5, 10, 15, and 20 breaths/min. All patients underwent ventilation with SIMV mode: pressure control ventilation, 16 cm H2O; inspiratory time, 0.8 s; triggering sensitivity, 0.6 l/min; and positive endexpiratory pressure, 3 cm H2O. After establishing steady-state conditions at each SIMV rate, arterial blood gases were analyzed, and esophageal pressure, airway pressure, and airflow were measured. Inspiratory work of breathing, pressure-time products, and the negative deflection of esophageal pressure were calculated separately for assisted breaths, for spontaneous breaths, and for total breaths per minute. Measurements were repeated after extubation. RESULTS: As the SIMV rate decreased, although minute ventilation and arterial carbon dioxide tension were maintained at constant values, spontaneous breathing rate and tidal volume increased. Work of breathing, pressure-time products, and negative deflection of esophageal pressure increased as the SIMV rate decreased. Work of breathing and pressure-time products after extubation were intermediate between those at a SIMV rate of 5 breaths/min and those at 0 breaths/min. CONCLUSION: When the load to breathing was increased progressively by decreasing the SIMV rate in post-cardiac surgery infants, tidal volume and spontaneous respiratory rate both increased. In addition, work of breathing and pressure-time products were increased depending on the SIMV rate.

Air Pressure↗
PubMed2001

Glucocorticoid suppresses neutrophil activation in ventilator-induced lung injury.

OBJECTIVE: To investigate, in a rat model, the role of the Mac-1/ICAM-1 pathway and the anti-inflammatory activity of steroid in ventilator-induced lung injury. DESIGN: Prospective, randomized controlled study. SETTING: Animal investigation using Wistar rats. INTERVENTION: Rats in three randomly assigned groups of 18, a total of 54 animals, were subject to the following: Two groups received high peak inspiratory pressure (35 cm H2O) ventilation after pretreatment with methylprednisolone (high-methylprednisolone group) or pretreatment with methylprednisolone vehicle (high-vehicle group). The third group of animals received low peak inspiratory pressure (7 cm H2O) ventilation after pretreatment with methylprednisolone vehicle (low-vehicle group). Except for animals previously killed to establish baseline values, after 40 mins of mechanical ventilation, the animals in each group were killed. Some animals provided histological samples, and the rest received total lung lavage. MEASUREMENT: We measured flow cytometry of lavage fluid, cell counts of tissue samples, and pressure-volume curves before and after mechanical ventilation. RESULTS: In the groups that received high peak inspiratory pressure ventilation, both the number of neutrophils that infiltrated the lungs and the expression of Mac-1 and ICAM-1 on neutrophils and macrophages increased significantly more than in the low-vehicle group. Static lung compliance was reduced in the high peak inspiratory pressure groups. In the high peak inspiratory pressure groups, there were significantly fewer neutrophils in samples from the high-methylprednisolone group (0.412 +/- 0.1 x 10(5)) than from the high-vehicle group (1.10 +/- 0.1 x 10(5); p < .05). The high-vehicle group showed greater expression of CD11b on neutrophils, but this was significantly decreased by methylprednisolone (mean fluorescence intensity: high-vehicle, 118.4 +/- 34.3; high-methylprednisolone, 25.8 +/- 4.2; p < .05). The lung mechanics measured by pressure-volume curve analysis were deteriorated less in the high-methylprednisolone group. CONCLUSION: Our study suggests that a neutrophil-endothelium interaction via the Mac-1/ICAM-1 pathway is involved in the activation and recruitment of neutrophils in ventilator-induced lung injury. Activation and recruitment of neutrophils were lessened by pretreatment with methylprednisolone, which might have contributed to the improvement of lung dysfunction after mechanical ventilation.

Animals↗
PubMed2001

Physiologic effects of transtracheal open ventilation in postextubation patients with high upper airway resistance.

OBJECTIVE: To investigate whether transtracheal open ventilation (TOV), pressure control ventilation (PCV) through a minitracheotomy tube (internal diameter 4 mm), is an effective method of inspiratory assistance under high upper airway resistance in postextubation patients; to compare, in a lung model study, TOV with other methods. DESIGN: Clinical study: A prospective, controlled, crossover study. Lung model study: A prospective laboratory trial. SETTING: Clinical study: A six-bed general intensive care unit in a teaching hospital. Lung model study: Animal research laboratory. PATIENTS: Clinical study: Eleven postextubation patients, who had undergone minitracheotomy for sputum retention between January 1997 and December 1997. SUBJECT: Lung model study: Two-bellows-in-a-box lung model, which included ordinary and high levels of upper airway resistance. INTERVENTIONS: Clinical study: Ventilatory settings were: assist/control (A/C) mode, 2 breaths/min of A/C back-up rate, 35-40 cm H2O of PCV, 0.6-0.8 secs of inspiratory time, and 0 cm H2O of positive end-expiratory pressure. The ventilatory parameters of TOV were compared with those of spontaneous breathing (SB). Lung model study: Effect of TOV on inspiratory assistance was compared with those of SB, open minitracheotomy, 5 L/min of transtracheal gas insufflation, and 5 and 10 cm H2O of pressure support ventilation (PSV), which simulated noninvasive positive ventilation. TOV ventilatory settings were: A/C mode; 30, 40, and 50 cm H2O of PCV, 0.9 secs of inspiratory time, and 0 cm H2O of positive end-expiratory pressure. At each ventilatory setting, we adjusted the inspiratory effort of the model to give a tidal volume of 0.5 L. MEASUREMENTS AND MAIN RESULTS: Clinical study: TOV was performed for 76.6 +/- 38.6 hrs (mean +/- sd) over 5.6 +/- 2.6 days without major complication. Peak tracheal pressure, which was measured distal to the minitracheotomy tube in six patients by a catheter pressure transducer, was 4.33 +/- 0.59 cm H2O. Inspiratory tidal volume delivered by the ventilator was 0.51 +/- 0.06 L. Respiratory rate during TOV was lower than during SB. According to esophageal pressure and respiratory inductive plethysmography, TOV reduced the patient's inspiratory work and improved the breathing pattern. Lung model study: Mean tracheal pressure during TOV and 10 cm H2O of PSV were positive values and they had larger inspiratory assistance according to the pressure-time product of pleural pressure. Although high upper airway resistance reduced the inspiratory assistance of PSV, it did not change the effects of TOV. CONCLUSIONS: TOV effectively reduced patient's inspiratory work and was more useful than open minitracheotomy and transtracheal gas insufflation. TOV also improved the breathing pattern. TOV may be useful for resolving some postextubation respiratory problems and avoiding the need for reintubation.

Aged↗
PubMed2001

Relationship between work of breathing provided by a ventilator and patients' inspiratory drive during pressure support ventilation; effects of inspiratory rise time.

Inspiratory drive and work of breathing provided by a ventilator (WOBv) during pressure support ventilation (PSV) were examined in 15 patients. At PSV 10 and 15 cm H2O during CPAP 5 cm H2O, patients with low P0.1 (<4.2 cm H2O, n=9) showed WOBv 0.57 and 0.92 J/l, those with high P0.1 (>4.2 cm H2O, n=6) showed 0.31 and 0.62 J/l respectively. WOBv was smaller and pressure-time product of oesophageal pressure (PTP) was significantly larger in high P0.1 patients. Peak inspiratory flow for low P0.1 patients increased as PSV level increased but high P0.1 patients showed no significant change. In a lung model, effects of inspiratory rise time (IRT) and PSV were studied at high and low inspiratory drives by using ventilators with (Servo 300) and without (Mallinckrodt 7200a) adjustable IRT. With 7200a, PSV 10 cm H2O during low drive was compared with PSV 10 and 15 cm H20 during high drive. In Servo 300, PSV 10 cm H2O (IRT 0.6 and 0.0 sec) during low drive was compared with PSV 10 cm H20 (IRT 0.6 and 0.0 sec) and PSV 15 cm H2O (IRT 0.6 sec) during high drive. Raising PSV and shortening IRT both increased peak inspiratory flow. Initial inspiratory flow increased in inverse proportion to IRT, but higher PSV had a little effect. WOBv with high drive was less than with low drive. Higher PSV preserved WOBv by increasing tidal volume. Shortening IRT recruited WOBv by increasing initial inspiratory flow without changing airway pressure and tidal volume. Compared with higher PSV, shorter IRT reduced PTP more. In conclusion, WOBv decreased as inspiratory drive increased due to inability to increase inspiratory flow. Increasing initial inspiratory flow was more effective than raising PSV to preserve inspiratory assistance of PSV at high inspiratory drive.

Adult↗
PubMed2001

Anti-alpha-fodrin antibodies in Sjögren's syndrome in children.

OBJECTIVE: To investigate the prevalence of anti-alpha-fodrin antibody specific for adult Sjögren's syndrome (SS) in patients with juvenile onset SS. METHODS: Serum anti-alpha-fodrin antibody was examined in 15 patients with juvenile SS (11 cases of primary SS and 4 secondary SS) and in 16 children with systemic lupus erythematosus (SLE) by Western blot analysis using a recombinant 120 kDa alpha-fodrin fusion protein. RESULTS: All the 15 serum samples from patients with SS reacted with a recombinant alpha-fodrin fusion protein in Western blot analysis. In contrast, reactivity was found in only 2 of the 16 patients with SLE. The clinical features of the 15 patients with juvenile onset SS were very specific; only 4 patients complained of dryness, while 6 had abnormal excretion ability. Salivary gland enlargement was the most common clinical manifestation. Characteristic laboratory findings in juvenile onset SS included a higher prevalence of antinuclear antibodies, anti-SSA/Ro antibodies, and rheumatoid factor, as well as increased erythrocyte sedimentation rate and hypergammaglobulinemia. CONCLUSION: The pathogenesis of juvenile SS seems to be the same as that of adult SS, although subjective symptoms of dryness are less frequent in juvenile cases. This discrepancy may indicate that SS is a slowly progressive disease with a long time span. The anti-alpha-fodrin antibody is likely to be a reliable diagnostic marker for juvenile SS.

Adolescent↗
PubMed2001

[A case of primary Sjögren syndrome with repeated purpura].

In Sjögren syndrome, purpura is one of its various well known eruptions. Although this disease state is assumed to be based on hypergammaglobulinemia, the details of its mechanism are unknown. We experienced a case involving a female patient with primary Sjögren syndrome showing repeated purpura on the legs, and examined her blood viscosity and histopathology. This girl developed Sjögren syndrome and was admitted to our hospital at 12-years-old. She underwent steroid treatment because of aggravation of the xerosis state and prominent purpura on the legs. Hypergammaglobulinemia was improved during the course; however, purpura appeared repeatedly. Although her blood viscosity was slightly higher than normal, this had no relation to purpura and serum gamma globulin values. Skin biopsy revealed necrotizing angiitis. These results suggest that the purpura of this case was caused not only by hyperviscosity from the hypergammaglobulinemia but also involvement of vasculitis by the primary disease.

Adolescent↗
PubMed2000

In vitro selection of aptamers that act with Zn2+.

An in vitro selection was carried out with Zn2+ to isolate novel RNA molecules, zinc-dependent aptamers, that bind to HIV-1 Tat protein. RNAs bound to Tat were collected by using a nitrocellulose filter from a library of random RNAs and regenerated to the next generation of the RNA library by subsequent reverse transcription, polymerase chain reaction, and transcription. Sequences of the selected RNAs were determined after 6 and 12 rounds of the selection. The control clones after normal selection procedure with Mg2+ had a consensus UUG that resembled essential sequences of TAR or Arg aptamers. On the other hand, many unique sequences were revealed from a library selected with Zn2+ and the RNA with most abundant sequence (clone 31) bound to Tat tightly only when Zn2+ existed. The secondary structure of clone 31 RNA was predicted by using a computational prediction with our thermodynamic parameters and enzymatic scission of the RNA. Several model RNAs were prepared and the binding property of these RNAs to Tat were investigated. As a result, all the model RNAs did not reproduce the binding property of clone 31. Therefore, the Tat aptamer that acts with Zn2+ should require a relatively longer region of the sequence which is able to offer tertiary cooperation of several motifs for the binding.

Base Sequence↗
PubMed2000

Effect of patient-triggered ventilation on respiratory workload in infants after cardiac surgery.

BACKGROUND: Patient-triggered ventilation (PTV) is commonly used in adults to avoid dyssynchrony between patient and ventilator. However, few investigations have examined the effects of PTV in infants. Our objective was to determine if pressure-control PTV reduces infants' respiratory workloads in proportion to the level of pressure control. We also explored which level of pressure control provided respiratory workloads similar to those after the extubation of the trachea. METHODS: When seven post-cardiac surgery infants, aged 1 to 11 months, were to be weaned with the pressure-control PTV, we randomly applied five levels of pressure control: 0, 4, 8, 12, and 16 cm H2O. All patients were ventilated with assist-control mode, triggering sensitivity of 1 l/min, and positive end-expiratory pressure of 3 cm H2O. After establishing steady state conditions at each level of pressure control, arterial blood gases were analyzed and esophageal pressure (Pes), airway pressure, and airflow were measured. Inspiratory work of breathing (WOB) was calculated using a Campbell diagram. A modified pressure-time product (PTPmod) and the negative deflection of Pes were calculated from the Pes tracing below the baseline. The measurement was repeated after extubation. RESULTS: Pressure-control PTV supported every spontaneous breath. By decreasing the level of pressure control, respiratory rate increased, tidal volume decreased, and as a result, minute ventilation and arterial carbon dioxide partial pressure were maintained stable. The WOB, PTPmod, and negative deflection of Pes increased as pressure control level was decreased. The WOB and PTPmod at 4 cm H2O pressure control and 0 cm H2O pressure control and after extubation were significantly greater than those at the pressure control of 16, 12, and 8 cm H2O (P < 0.05). The WOB and PTPmod were almost equivalent after extubation and at 4 cm H2O pressure control. CONCLUSIONS: Work of breathing and PTPmod were changed according to the pressure control level in post-cardiac surgery infants. PTV may be feasible in infants as well as in adults.

Cardiac Surgical Procedures↗
PubMed2000

Autotriggering caused by cardiogenic oscillation during flow-triggered mechanical ventilation.

OBJECTIVES: We noticed that in some patients after cardiac surgery, when flow triggering was used, cardiogenic oscillation might be autotriggering the ventilatory support. In a prospective study, we evaluated the degree of cardiogenic oscillation and the frequency rate of autotriggering. We suspected that autotriggering caused by cardiogenic oscillation was more common than clinically appreciated. DESIGN: Prospective, nonrandomized, clinical study. SETTING: Surgical intensive care unit in a national heart institute. PATIENTS: A total of 104 adult patients were enrolled after cardiac surgery. INTERVENTIONS: During the study period, patients were paralyzed and ventilated with intermittent mandatory ventilation at a rate of 10 breaths/min, pressure support of 10 cm H2O, and flow triggering with a sensitivity of 1 L/min. MEASUREMENTS AND MAIN RESULTS: Because the patients would not be able to breathe spontaneously, we counted pressure-support (PS) breaths as instances of autotriggering. Then, we classified the patients into two groups according to the number of PS breaths: an "AT group" (PS breaths of >5/min) and a "non-AT group" (PS breaths of < or =5/min). If autotriggering occurred, we decreased the sensitivity so autotriggering disappeared (threshold triggering sensitivity). The intensity of cardiogenic oscillation was assessed as the flow and airway pressure at the airway opening. A total of 23 patients (22%) demonstrated more than five autotriggered breaths/min. During mechanical ventilation, the inspiratory flow fluctuation caused by cardiogenic oscillation was significantly greater in the AT group than in the non-AT group (4.67+/-1.26 L/min vs. 2.03+/-0.86 L/min; p<.01). The AT group also showed larger cardiac output, higher ventricular filling pressures, larger heart size, and lower respiratory system resistance than the non-AT group. As the inspiratory flow fluctuation caused by cardiogenic oscillation increased, the level of triggering sensitivity also was increased to avoid autotriggering. In the AT group with 1 L/min of sensitivity, the respiratory rate increased (19.9+/-2.7 vs. 10+/-0 breaths/min, p<.01), Paco2 decreased (30.8+/-4.0 torr [4.11+/-0.36 kPa] vs. 37.6+/-4.3 torr [5.01+/-0.57 kPa]; p < .01), and mean esophageal pressure increased (7.7+/-3.0 vs. 6.9+/-3.0 cm H2O; p<.01) compared with the threshold triggering sensitivity. CONCLUSIONS: Autotriggering caused by cardiogenic oscillation is common in postcardiac surgery patients when flow triggering is used. Autotriggering occurred more often in patients with more dynamic circulation. Autotriggering caused respiratory alkalosis and hyperinflation of the lungs.

Adult↗
PubMed2000

Optimal level of pressure support ventilation for recovery from diaphragmatic fatigue in rabbits.

OBJECTIVE: To determine whether there is an optimal level of pressure support ventilation (PSV) for recovery from acute diaphragmatic fatigue. DESIGN: Prospective laboratory trial. SETTING: Experimental laboratory. SUBJECTS: Twenty healthy adult New Zealand White rabbits. INTERVENTIONS: Diaphragmatic fatigue was induced with 50 Hz of phrenic nerve stimulation for 30 mins. Recovery was compared between inspiratory load + PSV of 0 cm H2O (L0), inspiratory load + PSV of 60 cm H2O (L60), inspiratory load + PSV of 80 cm H2O (L80), and PSV of 0 cm H2O without inspiratory load (SB) for 90 mins immediately after the end of the fatigue-inducing procedure. To add inspiratory load during the recovery phase, three pressure threshold valves, each having an opening pressure of -20 cm H2O, were used. MEASUREMENTS AND MAIN RESULTS: After the fatigue-inducing procedure, diaphragmatic electromyogram and transdiaphragmatic pressure remained at baseline in both SB and L60, decreased in L80, and increased in L0. Recovery was assessed by abdominal cavity pressure (Pabd) generated by high-frequency (100 Hz) and low-frequency (20 Hz) stimulation. Pabd at 100 Hz recovered to baseline in L60 and SB but not in L0 and L80 (69.1%, 81.3%, 100.3%, and 100.7% of the baseline at 90 mins for L0, L80, L60, and SB, respectively). Pabd at 20 Hz did not differ among ventilatory settings. CONCLUSION: There is an optimal range of PSV assist level to improve recovery from diaphragmatic fatigue. Recovery was hampered not only by inadequate PSV but also by excessive PSV.

Airway Resistance↗
PubMed2000

Effects of nitric oxide inhalation after pulmonary thromboendarterectomy for chronic pulmonary thromboembolism.

STUDY OBJECTIVES: To examine the hypothesis that nitric oxide (NO) inhalation improves hemodynamics and gas exchange in patients with chronic pulmonary thromboembolism after pulmonary thromboendarterectomy. DESIGN: Prospective crossover clinical study. SETTING: : Surgical ICU in a national education and research hospital. PATIENTS: : Seven patients (mean age +/- SD, 54 +/- 11 years) who underwent elective pulmonary thromboendarterectomy for chronic pulmonary thromboembolism. INTERVENTIONS: Patients breathed 20 parts per million of NO gas for 30 min at 12-h intervals until extubation of the trachea. MEASUREMENTS AND RESULTS: Hemodynamics and arterial blood gas levels were analyzed before, during, and after NO inhalation. Waveform of pulmonary artery pressure (PAP) was evaluated using fractional pulse pressure (PPf): (systolic PAP - diastolic PAP)/mean PAP. After surgery, pulmonary vascular resistance decreased, PPf decreased, and cardiac index increased significantly. At the first trial, NO inhalation resulted in a slight improvement in arterial oxygen tension (from 173 +/- 33 to 196 +/- 44 mm Hg; p < 0.05), while hemodynamics did not change significantly. Twelve hours later, NO inhalation decreased pulmonary vascular resistance index (from 312 +/- 98 to 277 +/- 93 dyne.s. cm(-5)/m(2); p < 0.01), while the change in oxygenation was not significant. CONCLUSIONS: Immediately after pulmonary thromboendarterectomy for chronic pulmonary thromboembolism, NO inhalation improved oxygenation; at 12 h after surgery, NO inhalation resulted in decreased pulmonary vascular resistance, although both changes were small.

Aged↗
PubMed2000

[Behçet disease].

Explore the source record for details and available documents.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1999

Nitric oxide inhalation as a chemical assist for circulation in patients after cardiovascular surgery.

The objective of this study was to investigate whether nitric oxide (NO) inhalation might be an alternative strategy as a chemical assist for the circulation in patients showing a deterioration in oxygen delivery. Twelve adult patients whose oxygen delivery indices (DO2I) were less than 400 ml/min/m2 after cardiovascular surgery were included in this study. NO was administered via a premixing system or a side stream system at doses between 1 and 10 (5.1+/-2.4) ppm. Data obtained before and during a 120 min NO inhalation were compared using the paired Student's t-test. The increase in PaO2/FiO2 resulting from NO inhalation was significant (from 162 to 251 mm Hg). DO2I increased significantly from 326 to 417 ml/min/m2 concomitantly with significant increases in both arterial oxygen content (CaO2) and cardiac index (CI) (from 14.1 to 15.4 vol% and from 2.31 to 2.71 L/min/m2 , respectively). The increase in SvO2 during NO inhalation was significant (from 55.2 to 62.6%). Among the other hemodynamic parameters, both total pulmonary resistance and systolic pulmonary arterial pressure (SPAP) showed significant decreases during NO inhalation, but right atrial pressure did not change significantly. There was a close relationship between the baseline SPAP level (bSPAP) and the decrease in SPAP during NO inhalation (dSPAP) (r = -0.88). However, negative correlations were observed between bSPAP and percentage increase in CI (%CI) (r = -0.61) and between bSPAP and percentage increase in DO2I (%DO2I) (r = -0.48). Moreover, positive relationships were observed between dSPAP and %CI (r = 0.62) and between dSPAP and %DO2I (r = 0.45). Hemoglobin (Hb) increased significantly from 11.0 to 11.4 g/dl. There were no significant changes in Fio2, pH, PacO2, or base excess (BE) during NO inhalation. The level of methemoglobin measured during the study period remained within the normal range (0.86+/-0.23%). In conclusion, NO inhalation could be an efficient and alternative assist for the circulation in patients whose oxygen delivery deteriorates after cardiovascular surgery.

Administration, Inhalation↗
PubMed1999

Expiratory phase tracheal gas insufflation and pressure control in sheep with permissive hypercapnia.

Tracheal gas insufflation (TGI) has been shown to be a useful adjunct to mechanical ventilation, decreasing PaCO2 during permissive hypercapnia. While TGI can be used either with pressure (PCV) or volume-controlled ventilation and continuously or only during the expiratory phase (Ex-TGI), there are no controlled studies evaluating the effects of Ex-TGI with PCV in acute lung injury when the direction of the insufflated flow or the inspiratory:expiratory (I:E) ratio are varied. We evaluated the effect that Ex-TGI with PCV would have on CO2 removal during both direct and reverse insufflated flow direction with varied I:E ratios when peak airway pressure, total positive end-expiratory pressure (PEEP), and tidal volume (VT) were kept constant. In addition we examined the effect that insufflation flow directed toward the mouth (reverse flow) would have on the generation of PEEP compared with flow directed toward the carina (direct flow). After saline lavage, nine sheep were ventilated with PCV to a baseline PaCO2 of 80 mm Hg. Ex-TGI (10 L/min) was then randomly applied in the reverse and direct direction with I:E set at 1:2 or 2:1. During 1:2 I:E PaCO2 decreased from 78 +/- 4 mm Hg to 60 +/- 7 mm Hg (23.5 +/- 8.9%) with direct flow and to 64 +/- 5 mm Hg (18.5 +/- 5.5%) with reverse flow (p < 0.05), whereas during 2:1 I:E PaCO2 decreased from 80 +/- 4 mm Hg to 69 +/- 8 mm Hg (13.7 +/- 9.2%) with direct flow and to 66 +/- 4 mm Hg (17.2 +/- 4.4%) with reverse flow (p < 0.05). Greater PEEP was developed with direct flow (2.8 cm H2O I:E 1:2 and 4.0 cm H2O I:E 2:1) than with reverse flow (-0.9 cm H2O I:E 1:2 and -0.4 cm H2O I:E 2:1), p < 0.05. There was no difference in the PaCO2 change between I:E with reverse flow, but the PaCO2 decrease was greater (p < 0.05) during 1:2 versus 2:1 I:E with direct flow. CO2 removal during PCV and Ex-TGI is more consistent with reverse flow than with direct flow and PEEP level is less affected by TGI with reverse flow than with direct flow.

Animals↗
PubMed1999

[A case report of systemic lupus erythematosus patient with severe lupus retinopathy and antiphospholipid antibody].

An eleven-year-old boy with systemic lupus erythematosus (SLE) developed severe bilateral lupus retinopathy when he was in active stage of SLE. The patient, who had suffered from SLE for 3 years, was admitted to our hospital because of high grade fever, systemic lymphadenopathy, leukopenia, elevation of erythrocyte sedimentation rate and hypocomplementemia. The dose of prednisolone was increased considering he was exacerbated of SLE, however, the convulsion as CNS lupus occurred to him. After the event he noted loss of vision in his bilateral eyes. The ophthalmologic examination revealed the lesions of cotton-wool spots, retinal vessel dilatations and diffuse occlusions of the retinal arterioles and venules which were compatible with lupus retinopathy. Although the coagulation time was normal, antiphospholipid antibodies were positive at the time of ocular involvement. Careful attention should be paid to the occurrence of lupus retinopathy when the patients with SLE developed in the active stage or CNS lupus, especially they have antiphospholipid antibodies.

Antibodies, Antiphospholipid↗