An analysis of CO2 elimination curves during artificial ventilation

We have developed some indices to evaluate the phase III slope in CO₂ elimination curves. The indices were applied to 12 mechanically ventilated patients in ICU to determine their stability under various ventilator settings. F_co2-sl[30–90] and expressed the mean incline of phase III slope in F_co2-volume curves and -volume curves, respectively. F_co2-SR and -SR expressed the ratio of the slopes in the first and second halves of the phase III portion in both curves. The indices were also applied to 108 elective surgery patients to determine their usefulness in predicting ventilatory efficiency during general anesthesia. In the first study, F_co2-sl[30–90] and [30–90] correlated with ET_co2, V_d/V_t and the volume of CO₂ expired, but F_co2-SR and -SR were independent of these parameters. -SR did not show any significant changes under various ventilator settings except for application of PEEP. In the second study, those with impaired preoperative respiratory function had significantly larger values for . was as sensitive as parameters such as V_D/V_T, arterial to end-tidal CO₂ tension difference (a-ET·D_co2), and volume pressure index (VPI) in prediting poor respiratory functions. We concluded that is a useful index for evaluating the phase III slope in CO₂ elimination curves.     

Hyperventilation versus standard ventilation for infants in postoperative care for congenital heart defects with pulmonary hypertension

Purpose  In infants undergoing surgery for cardiac defects with left-to-right shunt, a hyperventilation strategy has been applied to prevent pulmonary hypertensive crisis (PHC). Hyperventilation with a large tidal volume and/or higher airway pressure, however, may be detrimental to the lung. This randomized study compared the effects of hyperventilation versus standard ventilation. Methods  We enrolled 22 infants with a preoperative pulmonary-to-systemic blood pressure ratio of more than 0.7. Hyperventilation, with a tidal volume of 10–12 ml·kg⁻¹ to keep between 30 and 35 mmHg, was randomly applied in 11 patients for 16 h or more. The other 11 patients were randomly assigned to standard ventilation, with a 6- to 8- ml·kg⁻¹ tidal volume. Results  The peak inspiratory pressure was higher (20 ± 3 vs 18 ± 2 cmH₂O; P = 0.018), and (34 ± 5 vs 42 ± 7 mmHg; P = 0.003) and positive end-expiratory pressure (3 ± 0 vs 5 ± 0; P < 0.0001) were significantly lower in the hyperventilation than in the standard ventilation group. The /inspiratory fraction of oxygen ratio decreased from 244 ± 160 mmHg at the onset of postoperative ventilation, to 177 ± 96 mmHg at 24 h (P = 0.038) in the hyperventilation group, versus a decrease from 240 ± 89 to 220 ± 97 mmHg in the standard ventilation group not significant (NS). Serum interleukin (IL)-6 level, measured at 24 h postoperatively, was significantly lower (P = 0.02) in the standard ventilation than in the hyperventilation group, suggesting an attenuated postoperative systemic inflammatory response. A single patient in each group developed PHC. Conclusion  Hyperventilation may cause lung injury and systemic inflammation in infants with pulmonary hypertension undergoing corrective heart surgery. T. Umenai and N. Shime contributed equally to this study.     

Prediction of postoperative delirium after abdominal surgery in the elderly

Purpose  Indications for the surgical treatment of elderly patients have been increasing. Postoperative central nervous system dysfunction, including delirium, is one of the most common complications in elderly surgical patients. The relationship between patient factors, including cerebral oxygen saturation, and the incidence of postoperative delirium was evaluated. Methods  Twenty American Society of Anesthesiologists (ASA) physical status I–II patients, older than 65 years, scheduled for elective abdominal surgery were enrolled in the study. The patients’ cognitive function was assessed, using the Hasegawa dementia score (HDS) and kana-hiroi test, on the day before surgery and then again 1 week after the surgery. Regional cerebral oxygen saturation () was continuously monitored during the surgery, using near-infrared spectroscopy (INVOS 3100). General anesthesia was induced with 3 mg·kg⁻¹ thiopental and 5% sevoflurane. After tracheal intubation, the sevoflurane concentration was adjusted to maintain the bispectral index (BIS) value between 45 and 60. Postoperative delirium was diagnosed if DSM IV criteria were present and the patient scored 12 or more points on the Delirium Rating Scale. Results  After surgery, 5 (25%) patients developed delirium. The age in the delirium (+) group (76 ± 4 years) was significantly higher than that in delirium (−) group (68 ± 3 years). Preoperative and postoperative HDS did not differ between the groups. The score on the preoperative kana-hiroi-test in the delirium (+) group (16 ± 5) was significantly lower than that in the delirium (−) group (32 ± 10). There were no significant differences between preoperative and postoperative kana-hiroi test scores in either group. Baseline in the delirium (+) group (60 ± 5%) was significantly lower than that in the delirium (−) group (66 ± 7%). However, there were no significant differences between the groups in the after the start of surgery. Conclusion  Patients’ age, low preoperative kana-hiroi test score, and low preoperative were important risk factors for postoperative delirium.     

Three-dimensional CT image analysis of a tracheal bronchus in a patient undergoing cardiac surgery with one-lung ventilation

The incidence of a tracheal bronchus—that is, a congenitally abnormal bronchus originating from the trachea or main bronchi–is 0.1%–2%. Serious hypoxia and atelectasis can develop in such patients with intubation and one-lung ventilation. We experienced a remarkable decrease in peripheral oxygen saturation () and a rise in airway pressure during placement of a double-lumen endobronchial tube in a patient with patent ductus arteriosus and tracheal bronchus. Substitution of the double-lumen tube with a bronchial blocker tube provided secure isolation of the lung intraoperatively. A type I tracheal bronchus and segmental tracheal stenosis were identified on postoperative three-dimensional (3D) computed tomographic (CT) images. Preoperative examination of chest X-rays, CT images, and preoperative tracheal 3D images should preempt such complications and assist in securing safe and optimal one-lung ventilation.     

Transmission electron microscopy of lattice planes in human alveolar bone apatite crystals

Summary Periodic fringes corresponding to six different lattice planes have been observed in apatite crystals of human normal alveolar bone by transmission electron microscopy. Three of these sets of fringes have spacings less than 3.5 ? corresponding to the Scherzer resolution of the microscope used. The (0002) lattice plane of hydroxyapatite of 3.4 ? d-spacings, the lattice plane with a d-spacing of 2.81 ?, and the lattice plane with a d-spacing of 2.72 ? have been identified. The (0002) and lattice planes have been observed for the first time in bone microcrystals. Some of the crystals studied were characterized by a mean width/thickness ratio of 6.91, typical of platelike habit, whereas observations of crystals aligned along the and directions showed a needlelike habit. The mean length of the bone apatite crystals was 470 ?. A dark line similar to the one observed in enamel and dentine crystals was also seen. The bone microcrystals observed have shown a high sensitivity to beam damage.     

Changes of oxygen transport variables and serum lactate during open-chest cardiac massage in dogs

The aim of this study was to investigate the influence of critically low cardiac output (CO) upon oxygen transport. We especially focused on the changes of mixed venous oxygen saturation (S−vO₂) in the presence of oxygen consumption ( ) debts. Additionally, we examined the correlation between the cumulative oxygen deficit (Def ) and serum lactate. Def was calculated as the integrated area under the tissue ) deficit (baseline -acutal ) and time curve. To produce severe low CO, we performed openchest cardiopulmonary resuscitation (CPR) in 11 anesthetized dogs for 1 h. We made the measurements before (baseline values) and during the CPR at 10-min intervals. Supplydependent was observed when CO decreased below 40 ml·min⁻¹·kg⁻¹. The mean value of S−vO₂ in the range of supply-dependent was 13±2% and did not change significantly during 1 h of CPR. The changes of lactate from baseline values were linearly correlated with Def (r=0.62,P<0.01), but absolute values of serum lactate were not.     

A neutrophil elastase inhibitor,sivelestat, improved respiratory and cardiac function in pediatric cardiovascular surgery with cardiopulmonary bypass

Purpose  Several reports indicate that a neutrophil elastase inhibitor, sivelestat, may have prophylactic efficacy against a systemic inflammatory response after cardiovascular surgery with cardiopulmonary bypass (CPB). We evaluated the clinical pulmonary and cardiac effects of sivelestat. Methods  We performed a retrospective study of 25 pediatric patients who underwent elective cardiovascular surgery with CPB for ventricular septal defect with pulmonary hypertension. Ten patients received 0.2 mg·kg⁻¹·h⁻¹ sivelestat; the other is patients were the control group. There were no significant differences in demographic characteristics between the two groups. The /fractional inspired oxygen (; P/F) ratio, the respiratory index (RI), and the fractional area change (FAC) of the left ventricle (LV) in the postoperative course were measured. Results  The P/F ratio was higher in the sivelestat group compared with the control group and there were significant differences between the two groups immediately after weaning form CPB, and at 12 h after weaning from CPB (P < 0.05). The RI was lower in the sivelestat group compared with the control group and there were significant differences between the two groups at immediately after weaning from CPB, and at 6 h and 12 h after CPB (P < 0.05). The FAC of the LV was significantly better in the sivelestat group and there was a significant difference between the two groups on postoperative day (POD) 3 (P < 0.05). Conclusion  We have shown that pediatric patients who underwent cardiovascular surgery with CPB who received sivelestat had a higher P/F ratio, a lower RI, and better FAC of the LV in the postoperative course.     

Relationship between cardiac output and mixed venous-arterialPco 2 gradient in sodium bicarbonate-treated dogs

We examined the relationship between cardiac output (CO) and mixed venous-arterialPco ₂ gradient ( ) along with the other variables derived from arterial and/or mixed venous blood gases in sodium bicarbonate-treated dogs. Six dogs with low cardiac output following cardiopulmonary resuscitation were used. CO, blood gases, and hemoglobin measurements were repeated every 20–30 min after administration of sodium bicarbonate or normal saline. All measurements were performed after the confirmation of a steady state of CO₂ elimination by end-tidal CO₂ monitoring. Arteriovenous oxygen content difference ( ), mixed venous oxygen saturation ( ), and were highly correlated with CO. The correlation coefficients between , , and werer=−0.81 (P<0.001),r=0.70 (P<0.001), andr=−0.77 (P<0.001), respectively. The results suggest that, if is measured during the steady state, except for the period during the transient increase in CO₂ elimination just after the administration of sodium bicarbonate, can be used as an index of systemic perfusion even after the administration of sodium bicarbonate.     

Comparative evaluation of TIVA with propofol-fentanyl and thiopental-sevoflurane anesthesia using laryngeal mask airway for diagnostic bronchoscopy

Purpose. Diagnostic bronchoscopy is performed under general anesthesia in our hospital. This study was designed to determine whether total intravenous anesthesia (TIVA) with propofol-fentanyl provides more stable hemodynamics using a laryngeal mask airway (LMA) for diagnostic bronchoscopy than thiopental-sevoflurane anesthesia. Methods. Sixty patients scheduled for diagnostic bronchoscopy were randomly assigned to two groups. TIVA with propofol-fentanyl was induced with intravenous fentanyl 2 μg·kg⁻¹ and propofol 2 mg·kg⁻¹ and maintained with continuous infusion of propofol with fentanyl. Thiopental-sevoflurane anesthesia was induced with thiopental 5 mg·kg⁻¹ and maintained with N₂O/O₂/sevoflurane. Insertion of the LMA was facilitated with vecuronium 0.1 mg·kg⁻¹ i.v. in both groups. Ventilation was controlled, and administration of propofol and sevoflurane was continued until the end of the procedure. The LMA was removed when the patient was able to open his or her mouth. Results. During TIVA, the mean arterial pressure and rate pressure product decreased significantly from induction until 20 min after the start of the procedure, and they were maintained at around 70 mmHg and 7000, respectively, during the procedure. There were no significant differences in heart rate, and . In thiopental-sevoflurane anesthesia, the mean arterial pressure and rate pressure product decreased significantly after induction and increased significantly from insertion of the LMA until removal of the LMA. Heart rate increased significantly after insertion of the LMA, insertion of the bronchoscope, and removal of the LMA. There were no significant differences in and . Conclusion. TIVA with propofol-fentanyl in conjunction with an LMA performs better than thiopental-sevoflurane anesthesia for diagnostic bronchoscopy because of its superior maintenance of cardiovascular stability.     

Cardiorespiratory dynamics during successful and unsuccessful trials of weaning from mechanical ventilation following cardiac surgery

The purpose of this study was to examine the effects of a weaning trial with pressure support ventilation (PSV) on the cardiorespiratory dynamics in 20 cardiac surgery patients. In the patients who failed a weaning trial (failure group,n=6), the mean duration of cardiopulmonary bypass was 270±83 min and the mean postoperative lung-thorax compliance was 38±5 ml·cmH₂O⁻¹, whereas in successfully weaned patients (success group,n=14) they were 145±30 min and 55±10 ml·cm H₂O⁻¹ respectively (mean±SD). Significant differences were recognized in those values between the two groups. Preoperative cardiac function, intraoperative blood loss, and postoperative fluid balance were similar in both groups. Cardiac index (CI) increased similarly in both groups. Pao₂/FIo₂ and percentage intrapulmonary shunt were constant in the success group, and these variables worsened in the failure group. Oxygen consumption ( ) increased and mixed venous O₂ tension ( ) decreased in the failure group, whereas remained constant and increased in the success group. These data suggest that prolonged cardiopulmonary bypass might have produced acute lung injury. Decreased lung compliance may be responsible for rapid shallow breathing and an increase in oxygen consumption during a weaning trial, and may lead to weaning failure from mechanical ventilation.     

Transcutaneous CO2 tension measurement as an indicator of severity of hemorrhagic shock

This study was undertaken to evaluate whether transcutaneous CO₂ tension (PtcCO₂) could be used as an indicator of the global systemic severity of hemorrhagic shock. PtcCO₂ levels in ten anesthetized mongrel dogs were measured during hemorrhage and during volume restoration and were correlated with mixed venous CO₂ tension ( ). After withdrawal of 30ml·kg⁻¹ blood, both PtcCO₂ and increased significantly (from 43±7 to 70±27 torr (P<0.05) and from 48±6 to 59±12 torr (P<0.05), respectively). Throughout the experiments, PtcCO₂ levels changed almost in parallel to levels. However, changes in PtcCO₂ exceeded those in from the end of hemorrhage, at which time cardiac output decreased to 35% of the baseline value, until the end of volume restoration, and the changes in PtcCO₂ showed a close logarithmic relationship with (r=0.78,n=110). Additionally, arterio-transcutaneous CO₂ tension gradients showed a close exponential correlation with cardiac output per body weight (CO/BW) during the shedding phase (r=0.85,n=60), although the correlation with CO/BW lessened during the retransfusion phase (r=0.55,n=60). PtcCO₂ was roughly correlated with during hemorrhagic shock, and levels of PtcCO₂ higher than reflected critical tissue perfusion.     

Fluctuating CPAP (F-CPAP) versus conventional CPAP (C-CPAP) in dogs with blood aspiration

Fluctuating CPAP(F-CPAP) is a combination of spontaneous ventilation and fluctuating PEEP, in which end-expiratory pressure (EEP) is periodically changed within a certain range. In a dog model with localized lung injury induced by the aspiration of non-heparinized blood (2ml·kg^–1 body weight), we carried out a comparative study of the effects of F-CPAP in which the EEP was cyclically changed from 4 to 12cmH₂O with periods of 10min and those of conventional CPAP with a fixed EEP of 8cmH₂O (C-CPAP), on hemodynamics and pulmonary oxygenation. The blood aspiration produced significant increases in the intrapulmonary shunt ( sp/ t), the alveolar-arterial difference of partial pressure of oxygen (A-aDo ₂), and the respiratory rate (RR). Although both F-CPAP and C-CPAP reduced sp/ t and A-aDo ₂ and RR, 7 dogs treated with F-CPAP showed a significantly greater recovery of sp/ t and A-aDo ₂ than 7 dogs treated with C-CPAP. There were no significant differences in hemodynamic variables between the two groups. These results suggest that F-CPAP is more useful in the treatment of some kinds of hypoxic respiratory failure due to uneven distribution of lung injury.(Sakurada M, Inaba H, Sato J, et al.: Fluctuating CPAP (F-CPAP) versus conventional CPAP (C-CPAP) in dogs with blood aspiration. J Anesth 5: 36–42, 1991)     

Hypoxic ventilatory response in cats lightly anesthetized with ketamine: effects of halothane and sevoflurane in low concentrations

The effect of low concentration sevoflurane and halothane on the ventilatory response to isocapnic hypoxia was studied in sixteen cats. The cats were divided into two groups, sevoflurane group and halothane group, of eight subjects each. As parameters of the hypoxic ventilatory response, A value [the slope of the hyperbolic curve, _E = ₀ + A/(Pa_{O 2}-32)] and ratio of ₅₀ (the minute volume obtained from the hyperbolic equation when Pa_{O 2} = 50mmHg) to ₀ were studied. These two parameters were examined at three states, sedative state with ketamine as the control, ketamine plus 0.1MAC inhalation anesthetic, and ketamine plus 0.5MAC inhalation anesthetic.In the sevoflurane group, the A values were 4789 ± 1518, 2187 ± 1214, 1730 ± 880 (mean ± SE. ml·min^–1·mmHg) at the control state, 0.1MAC and 0.5MAC, respectively. In the halothane group, the A values were 6411 ± 2368, 2529 ± 842 and 2372 ± 545, respectively. The ratios of ₅₀ to ₀ were 1.32 ± 0.09, 1.22 ± 0.09, 1.25 ± 0.08 in the sevoflurane group, 1.47 ± 0.18, 1.32 ± 0.11, 1.54 ± 0.18 in the halothane group, respectively. The A value at 0.1MAC of the halothane group was less than the control value significantly. This proved that even low concentration halothane depressed the hypoxic ventilatory responses. The depression of hypoxic ventilatory response could cause postanesthetic hypoventilation. On the other hand, we could not find significant depression on the hypoxic ventilatory response in the sevoflurane group, but we should notice that variances of the hypoxic ventilatory response were large.(Tamura C, Doi M, Ikeda K: Hypoxic ventilatory response in cats lightly anesthetized with ketamine: Effects of halothane and sevoflurane in low concentrations. J Anesth 5: 233–238, 1991)     

Prediction of lung cancer spread and functional resectability by133Xe radiospirometry

Sixty-six patients with primary lung cancer who underwent thoracotomy were studied to determine the correlations among¹³³Xe radiospirometry, surgical procedures and histological extension of the lung cancer. Disturbance in the regional perfusion ( per cent) was more prominent than disturbance of the regional ventilation ( per cent), as the pathological stage and t factor proceeded, while per cent and per cent were disturbed almost equally in relation to the pathological n factor. Lobectomy was impossible in patients with a per cent of less than 33 per cent of the total, but low perfusion did not necessarily contraindicate surgery. The predicted post-operative FEV_1.0 was calculated according to the equation of (1-b/a × ( per cent or per cent)) × (preoperative FEV_1.0), where a and b were the number of subsegments in the lung lobes on the involved side and the resected lobe. The predicted and actually measured postoperative FEV_1.0 showed significant correlations (<0.001) in both equations. We conclude that per cent reflects a complex pattern of lung cancer spread more sensitively than does per cent, and the significance of per cent and per cent in terms of prediction of postoperative EFV_1.0 seems to be equivocal.     

Fourier transform raman spectroscopy of synthetic and biological calcium phosphates

Fourier-transform (FT) Raman spectroscopy was used to characterize the organic and mineral components of biological and synthetic calcium phosphate minerals. Raman spectroscopy provides information on biological minerals that is complimentary to more widely used infrared methodologies as some infrared-inactive vibrational modes are Raman-active. The application of FT-Raman technology has, for the first time, enabled the problems of high sample fluorescence and low signal-to-noise that are inherent in calcified tissues to be overcome. Raman spectra of calcium phosphates are dominated by a very strong band near 960 cm^–1 that arises from the symmetric stretching mode of the phosphate group. Other Raman-active phosphate vibrational bands are seen at approximately 1075 , 590 , and 435 cm^–1 . Minerals containing acidic phosphate groups show additional vibrational modes. The different calcium phosphate mineral phases can be distinguished from one another by the relative positions and shapes of these bands in the Raman spectra. FT-Raman spectra of nascent, nonmineralized matrix vesicles (MV) show a distinct absence of the phosphate band even though these structures are rich in calcium and phosphate. Similar results were seen with milk casein and synthetic Ca-phosphatidyl-serine-PO₄ complexes. Hence, the phosphate and/or acidic phosphate ions in these noncrystalline biological calcium phosphates is in a molecular environment that differs from that in synthetic amorphous calcium phosphate. In MV, the first distinct mineral phase to form contained acidic phosphate bands similar to those seen in octacalcium phosphate. The mineral phase present in fully mineralized MV was much more apatitic, resembling that found in bones and teeth. These findings are consistent with formation of an OCP-like precursor during MV mineral formation that subsequently hydrolyzes to form hydroxyapatite.     

Hemodynamics in pulmonary embolism,with special reference to pulmonary capillary blood flow

We determined the effect of heparin pretreatment in modifying the pulmonary hypertension and reduced pulsatility of pulmonary capillary blood flow ( ) wave observed after thrombo-embolization in dogs. In vivo thrombi were produced in 24 dogs, 12 of which were pretreated with heparin. Pulmonary arterial pressure and , using the body plethysmograph-nitrous oxide method, were measured before and after the release of emboli. Alteration in pulsatily of instantaneous were quantitated by changes in the peak-to-mean flow ratio ( max/ ), the ratio of peak flow to stroke volume ( max/SV) and the percentage of stroke volume flowing through the capillaries during systole (V_syst/SV). Mean did not change significantly after embolization in the control (Group I) or heparinized animals (Group II). Mean pulmonary arterial pressure increased 70 per cent in mild embolism of Group I and 240 per cent in severe embolism. In Group II corresponding increases were 49 per cent and 115 per cent. In Group I, max/ , max/SV and V_syst/SV decreased significantly during embolic period of mild and severe embolism. There was no significant change in pulsatility in Group II when five or less segments of second tributory of pulmonary artery were obstructed. With more diffuse embolization the reduction on pulsatility was similar to Group I. Transient pulmonary hypertension and decreased pulsatility with minimal or moderate vascular obstruction by emboli indicate diffuse precapillary vasoconstriction. This is modified but not prevented by heparin, depending on the extent of embolization. This work was initiated at the Pulmonary Function Laboratory, Albert Einstein Medical Center, Philadelphia, Pa.     

RETRACTED ARTICLE: Airway occlusion pressure is an indicator of respiratory depression with isoflurane

The purpose of this study was to elucidate the respiratory depressant effects of isoflurane (0%–1.0%) using airway occlusion pressure (P_0.1), a known index of the output of the respiratory centers, in ten anesthetized patients. P_0.1 was measured as the pressure change obtained after the first 0.1 sec of spontaneous inspiration against the occluded airway. A significant decrease in minute volume ( ) and a significant increase in Pa_{CO 2} were not observed during the periods of isoflurane 1.0% at the end-tidal concentration compared with those of control period (0% isoflurane) (P<0.05), whereas a significant decrease in P_0.1 was observed during the period of isoflurane 0.5%. Our results suggested that P_0.1 was a more sensitive indicator of respiratory depression than Pa_{CO 2} or , and the respiratory center was depressed with a considerably lower concentration (0.5%) of isoflurane.     

Effects of four volatile anesthesics on postanesthetic ventilation: a comparison of halothane,enflurane, isoflurane,and sevoflurane

To investigate the effects of four volatile anesthetics (halothane, enflurane, isoflurane, and sevoflurane) on postanesthetic ventilation and levels of consciousness, we enrolled 24 patients undergoing tympanoplasty in this study. Anesthesia was maintained with 67% nitrous oxide and one of four volatile anesthetics. We measured end-tidal carbon dioxide concentration (C_ETco₂), minute volume ( ) and respiratory rate (RR), and determined the volatile anesthetic concentration in whole arterial blood (C_BAnesth) and arterial carbon dioxide tension (Paco₂) at 20 min and 2h after tracheal extubation. We also observed the level of consciousness (awake, drowsy, and asleep) before the measurement. Ventilatory variables were similar among the four groups at 20 min, although the ratio of volatile anesthetic concentration in the alveoli to the minimum alveolar concentration (MAC) (C_AAnesth/MAC ratio) calculated from C_BAnesth in the halothane group was twice those in the other groups. In the halothane group, Paco₂ was significantly higher, and and RR were significantly lower compared with the isoflurane and sevoflurane groups at 2h. Halothane tended to prolong the recovery of levels of consciousness. We conclude that isoflurane and sevoflurane provide clinical advantages over halothane on postanesthetic ventilation and recovery of levels of consciousness.     

381. Die operative Therapie beim Thoraxtrauma — eine retrospektive Studie

Zusammenfassung Nach multiplem Trauma sinken intracelluläre Aktivität und Konzentration der Elastase in polymorphkernigen Leukocyten (PMNL), die aus Blut ( = 67 U und 6154 g/10⁹ PMNL) und bronchoalveolärer Lavage (BAL)-Flüssigkeit ( = 44 U und 5957 g/10⁹ PMNL) isoliert wurden im Vergleich zu PMNL Gesunder ( = 106 U und 9962 g/10⁹ PMNL). Gleichzeitig wurde ein Anstieg der extracellulären Elastase-Konzentration in Plasma von = 84 g/1 auf = 399 g/1 und in BAL Flüssigkeit von = 8 g/1 auf = 561 g/1 beobachtet. Die durch Stimulation freigesetzte Elastase wird teilweise von einem spezifischen Receptor auf PMNL erneut gebunden. Die Ergebnisse unterstützen die PMNL-vermittelte ARDS-Pathogenese.     

Laparoscopic surgery in children is associated with an intraoperative hypermetabolic response

Background Laparoscopic surgery is thought to be associated with a reduced metabolic response compared to open surgery. Oxygen consumption ( ) and energy metabolism during laparoscopic surgery have not been characterized in children. Methods We measured respiratory gas exchange intraoperatively in children undergoing 19 open and 20 laparoscopic procedures. Premature infants and patients with metabolic, renal, and cardiac abnormalities were excluded. Anesthesia was standardized. Unheated carbon dioxide was used for insufflation. was measured by indirect calorimetry. Core temperature was measured using an esophageal temperature probe. Results We found a steady increase in during laparoscopy. The increase in was more marked in younger children and was associated with a significant rise in core temperature. Open surgery was not associated with significant changes in core temperature or . Conclusions Laparoscopy in children is associated with an intraoperative hypermetabolic response characterized by increased oxygen consumption and core temperature. These changes are more marked in younger children. M. C. McHoney and L. Corizia contributed equally to the study, analysis, and writing of the paper