Natsuo Honda

Respiratory mechanics and arterial blood gases during and after laparoscopic cholecystectomy

PurposeThe purpose of this study was to assess the effects of increased intra-abdominal pressure due to CO2 insufflation on the mechanical characteristics of the respiratory system and arterial blood gases during and after laparoscopic cholecystectomy.MethodsRespiratory mechanics and arterial blood gases were examined in 12 patients undergoing laparoscopic cholecystectomy with CO2 insufflation. Respiratory mechanics were continuously monitored with in-line spirometry. In the recovery room, PaCO2 was measured in this group at 30 min and compared with PaCO2s in 23 patients who had undergone open cholecystectomy retrospectively, to evaluate the effects of insufflation on CO2 elimination.ResultsMinute ventilation was decreased by about 500 ml·min−1 during abdominal insufflation. Dynamic lung compliance decreased from 49.6 ± 4.7 to 30.7 ±2.3 (mean ± SEM) ml·cmH2O−1 with abdominal insufflation (P < 0.005), and returned to 45.1 ±3.1 after the release of pneumoperitoneum. Peak inspiratory pressure increased from 15.9 ± 0.9 to 18.9 ± 1.0 cmH2O with abdominal insufflation (P < 0.05). Arterial blood gas determinations indicated a decrease in arterial pH, with CO2 retention during insufflation and in the recovery room (P < 0.05). PaCO2 of the laparoscopic patients was higher than that of the open patients in the recovery room.ConclusionThe results indicate that respiratory acidosis was caused during CO2 insufflation for laparoscopic cholecystectomy, that was due to (1) decreased compliance, (2) increased CO2 load and (3) insufficient ventilation. Accumulated CO2 during laparoscopic cholecystectomy increased PaCO2 level in the recovery room.RésuméObjectifEvaluer les effets de l’augmentation de pression intraabdominale provoquée par l’insufflation de CO2 sur les caractéristiques du système respiratoire et des gaz du sang artériel pendant et après la cholécystectomie laparoscopique.MéthodeLa mécanique respiratoire et les gaz du sang artériels ont été étudiés chez 123 patients soumis à une cholé-cystectomie laparoscopique avec insufflation de CO2. La mécanique respiratore a été monitorée en continu par spirométrie. A la salle de réveil, la PaCO2 a été mésurée à la 30e min de l’admission et comparée rétrospectivement à la PaCO2 de 23 patients qui avaient subi une cholécystectomie ouverte, dans le but d’évaluer les effets de l’insufflation sur l’élimination du CO2.RésultatsLa ventilation minute a diminué d’environ 500 ml·min−1 pendant l’insufflation abdominale. La compliance dynamique pulmonaire diminuait de 49,6 ± 4,7 à 30,7 ± 2,3 (moyenne ± SEM) ml·cmH2O−1 avec l’insufflation (P < 0,005) et revenait à 45,1 ± 3,1 après le relâchement du pneumopéritoine. L’analyse des gaz artériels a révélé une diminution du pH artériel avec rétention de CO2 pendant l’insufflation et à la salle de réveil (P < 0,005). La PaCO2 des patients opérés sous laparoscopie était plus élevée que celle des patients opérés par chirurgie ouverte.ConclusionCes résultats indiquent que l’insufflation de CO2 pour la cholécystectomie laparoscopique provoque de l’acidose respiratoire causée 1) par la baisse de la compliance, 2) l’augmentation du volume de CO2 et 3) l’insuffisance ventilatoire. L’accumulation du CO2 pendant la cholécystectomie laparoscopique augmente la PaCO2 à la salle de réveil.

Glucose intolerance during prolonged sevoflurane anaesthesia.

PurposeThe effects of prolonged sevoflurane anaesthesia on insulin sensitivity were investigated by two successive intravenous glucose tolerance tests (IVGTT) in eight patients who underwent prolonged surgery.MethodsThe first IVGTT was administered (25 g glucose as 20% dextrose in water iv) over two minutes 35 min after initiation of surgery. Arterial blood samples were obtained at 0, 5, 10, 30, 60, and 120 min after glucose administration for blood glucose and plasma insulin determination. A second IVGTT was performed six hours following the initiation of surgery.ResultsThe disappearance rate of glucose (k-value) for the first IVGTT was 0.887 ± 0.436 (mean ± SD) % · min−1, and 0.784 ± 0.289 for the second IVGTT. Both k-values are lower than the normal value. The maximum insulin response to glucose (ΔIRI · ΔBS−1) of the second IVGTT was lower than the first IVGTT (0.124 ± 0.092 vs 0.071 ± 0.056, P < 0.05). The total insulin output of the first IVGTT was higher than the second IVGTT (1,161 ± 830 vs 568 ± 389 μU · min · ml−1, P < 0.05).ConclusionGlucose intolerance is enhanced by diminished insulin output in response to blood glucose elevation during prolonged anaesthesia and surgery.RésuméObjectifLa réalisation d’épreuves d’hyperglycémie provoquée (HGP) chez huit patients soumis à une chirurgie de longue durée visait à étudier les effets de l’administration prolongée de sévoflurane sur la sensibilité à l’insuline.MéthodesLa première épreuve d’HGP (25 g de glucose administrés iv sous la forme d’une solution glucosée 20% dans l’eau) a été effectuée en deux minutes, 35 min après le début de la chirurgie. Des échantillons de sang artériel ont été prélevés 0, 5, 10, 30, 60 et 120 min après l’administration de glucose pour déterminer la glycémie et l’insulinémie. Une deuxième HGP a été réalisée six heures après le début de la chirurgie.RésultatsLes résultats de la première HGP ont montré que la vitesse de disparition du glucose (valeur k) était de 0,887 ± 0,436 (moyenne ± ET)% · min−1, alors que la deuxième épreuve titrait 0,784 ± 0,289. La réponse insulinique maximale au glucose (ΔIRI · ΔBS−1) de la deuxième HGP était inférieure à celle de la première (0,124 ± 0,92 vs 0,071 ± 0,056, P < 0,05). Avec la première HGP, le débit total de l’insuline était plus élevé qu’avec la deuxième (1,161 ± 830 vs 568 ± 389 μU · min · ml−1, P < 0.05).ConclusionL’intolérance au glucose est amplifiée par une baisse de la production d’insuline en réponse à l’élévation de la glycémie pendant l’anesthésie et la chirurgie prolongées.

A simplified method for crosscorrelation analysis

Abstract A simple method of obtaining a crosscorrelogram between two waveforms has been described. Comparison between the formal method of crosscorelation and the simplified procedure demonstrates a good similarity of the results obtained.

A simplified method for autocorrelation analysis in electroencephalography.

Abstract a simple method of obtaining an auto-correlogram of the wave form has been described. Comparison between the orthodox method of auto-correlation and the simplified procedure demonstrates a good similarity of the results, provided that the wave form under analysis is of adequate lenght.

A simplified method for determining the average response time-pattern of the evoked potential in electroencephalography

Abstract A method has been described to obtain the average response time-pattern of evoked potentials in the electroencephalogram. This method is particularly useful for short recording periods. Comparison has been made to Dawsons summation technique of demonstrating evoked responses; improvement and clarity of the calculated responses is shown.

Malignant hyperthermia and althesin

SummaryGeneral anaesthesia with Althesin was administered on two occasions to a patient who was identified as susceptible to malignant hyperthermia, in whom there was identified familial subclinical myopathy and once in another patient suffering from arthrogryposis multiplex congenita with a history of fever associated with two previous anaesthetics. In the first patient halothane was administered by accident in association with the Althesin, but no hyperpyrexia occurred. In the second instance nitrous oxide-oxygen and halothane were associated purposely with Althesin. In none of these cases was there any rise in temperature, muscle rigor or elevation of the serum CPK level. This experience corroborates the experimental evidence of Hall,et al.10 and Harrison,11 who reported that Althesin prevented the onset of hyperthermia, and the clinical reports of Page12 and Judelman.13 Althesin can be assumed to be an effective anaesthetic for malignant hyperthermia susceptible patients.RésuméĽAlthésin a été utilisé à deux reprises lors ľinterventions ophtalmologiques chez un enfant ayant présenté antérieurement un épisode ľhyperthermie maligne. A la suite de cet épisode, une étude familiale électromyographique avait démontré une susceptibilité à la maladie. Lors de la seconde anesthésie à ľAlthésin, de ľHalothane a été ajoutée accidentellement au protoxyde ľazote utilisé en maintien.Chez un second enfant, avec une histoire de température lors de deux anesthésies antérieures, ľAlthésin a également été utilisé avec du protoxyde ľazote et, cette fois-ci, on a ajouté volontairement de ľHalothane au protoxyde.Dans tous les cas, nous n’avons observé aucune élévation de température, aucune rigidité musculaire et aucune modification des CPK.Ceci confirme les énoncés de Hall et coll., ainsi que ceux de Harrison, à savoir ľAlthésin prévient ľhyperthermie et vient s’ajouter aux rapports cliniques de Page et Judelman sur la sécurité de cet agent pour les malades avec une susceptibilité connue à ľhyperthermie maligne.

Continuous monitoring of ventilatory mechanics during one-lung ventilation

Objective. The Ultima SV respiratory monitor can be used to monitor the intraoperative effects of the lateral decubitus position and one-lung ventilation on ventilatory mechanics.Methods. Eight patients with esophageal cancer who required one-lung ventilation for esophagectomy and reconstruction were enrolled in the study. We monitored pressure-volume or flow-rate-volume loops continuously throughout the operation. Respiratory parameters were evaluated closely during five conditions of ventilation: two-lung ventilation in the supine position, two-lung ventilation in the lateral decubitus position, dependent one-lung ventilation in the lateral decubitus position, nondependent one-lung ventilation in the lateral decubitus position, and dependent one-lung ventilation in the lateral decubitus position with the chest opened. Respiratory rate was controlled at 10 breaths/min, and tidal volume was kept constant (10 ml/kg) during surgery.Results. Peak inspiratory pressure increased to 29.0 ± 9.0 (mean ± SD) cm H2O in the dependent one-lung in the lateral decubitus position with the chest opened (p < 0.01). Dynamic compliance decreased to 29.4 ± 4.9 ml/cm H2O in the dependent one-lung in the lateral decubitus position with the chest opened (p < 0.01). The changing configuration of the loops also offered additional and instantaneous information during one-lung ventilation.Conclusions. One-lung ventilation caused several changes in the whole respiratory system (lung, thorax, and endotracheal tube). Continuous monitoring of flow-rate-volume or pressure-volume loops with in-line spirometry provided comprehensive information regarding parameters in one-lung ventilation.

Compartment syndrome after prolonged lithotomy position in patient receiving combined epidural and general anesthesia

The compartment syndrome is a rare, but potentially serious complication observed in patients who undergo prolonged procedures in the lithotomy position. Because of providing relief of postoperative pain, postoperative epidural analgesia may mask symptoms and signs of the compartment syndrome, delaying diagnosis and treatment1 • The following case report describes such a patient who underwent prolonged genitourinary surgery in the lithotomy position with general and epidural anesthesia, but the compartment syndrome was suspected with measuring the compartment pressure.

Anesthetic Management of Axillo-Femoral Bypass for a Patient with Atypical Coarctation of the Aorta with Multiple Severe Stenosis

下行大動脈から腹部大動脈にかけて発生した数箇所の高度多発性狭窄により心不全を呈した異型大動脈縮窄症の患者に対して,後負荷軽減の目的で施行された腋窩-大腿動脈バイパス術の麻酔を経験した.術中は後負荷軽減と心拍出量増加のため,血管拡張療法とカテコラミンを併用したが,術前からの脱水と導入後の血管拡張により血圧が低下したため輸液負荷を必要とした.術中心不全に陥ることはなかった.術後覚醒と同時に末梢血管収縮に伴う相対的な循環血液量過多による左心不全となったため,血管拡張薬の再開と利尿剤を使用したところ,以後利尿良好となり,血行動態も安定して,術後2時間で肺動脈楔入圧は術前値まで低下した.今回のように後負荷の増大した症例では,術直後覚醒させる場合,バイパス効果の補助としての血管拡張療法の継続と利尿剤の併用による前負荷の軽減が必要である.

Hemodynamic and oxygen delivery-consumption changes during partial liver resection

The effects of partial liver resection on hemodynamics and the oxygen delivery-consumption relationship were evaluated in ten patients with hepatocellular carcinoma. The cardiac index and oxygen delivery were increased significantly (P < 0.05) at 30 minutes after incision, 30 min after liver resection and in the recovery room. Oxygen delivery decreased significantly (P < 0.05) during liver resection. Oxygen consumption remained low throughout the procedure. We did not discover any flow-dependent change in oxygen consumption. Although our patients persisted a hyperdynamic state throughout surgery, their arterial ketone body ratio remained low. Therefore, it may be necessary to maintain a hyperdynamic state during partial liver resection in order to increase hepatic blood flow.