Arterial to End-tidal Carbon Dioxide Pressure Difference during Laparoscopic Surgery in Pregnancy

Background: There is controversy about whether capnography is adequate to monitor pulmonary ventilation to reduce the risk of significant respiratory acidosis in pregnant patients undergoing laparoscopic surgery. In this prospective study, changes in arterial to end-tidal carbon dioxide pressure difference (PaCO2--PetCO2), induced by carbon dioxide pneumoperitoneum, were determined in pregnant patients undergoing laparoscopic cholecystectomy.

Methods: Eight pregnant women underwent general anesthesia at 17-30 weeks of gestation. Carbon dioxide pnueumoperitoneum was initiated after obtaining arterial blood for gas analysis. Pulmonary ventilation was adjusted to maintain PetCO2 around 32 mmHg during the procedure. Arterial blood gas analysis was performed during insufflation, after the termination of insufflation, after extubation, and in the postoperative period.

Results: The mean +/- SD for PaCO2--PetCO2 was 2.4 +/- 1.5 before carbon dioxide pneumoperitoneum, 2.6 +/- 1.2 during, and 1.9 +/- 1.4 mmHg after termination of pneumoperitoneum. PaCO2 and p H during pneumoperitoneum were 35 +/- 1.7 mmHg and 7.41 +/- 0.02, respectively. There were no significant differences in either mean PaCO2--PetCO2 or PaCO2 and p H during various phases of laparoscopy.     

Arterial to end-tidal carbon dioxide pressure difference during laparoscopic surgery in pregnancy

BACKGROUND: There is controversy about whether capnography is adequate to monitor pulmonary ventilation to reduce the risk of significant respiratory acidosis in pregnant patients undergoing laparoscopic surgery. In this prospective study, changes in arterial to end-tidal carbon dioxide pressure difference (PaCO2--PetCO2), induced by carbon dioxide pneumoperitoneum, were determined in pregnant patients undergoing laparoscopic cholecystectomy. METHODS: Eight pregnant women underwent general anesthesia at 17-30 weeks of gestation. Carbon dioxide pnueumoperitoneum was initiated after obtaining arterial blood for gas analysis. Pulmonary ventilation was adjusted to maintain PetCO2 around 32 mmHg during the procedure. Arterial blood gas analysis was performed during insufflation, after the termination of insufflation, after extubation, and in the postoperative period. RESULTS: The mean +/- SD for PaCO2--PetCO2 was 2.4 +/- 1.5 before carbon dioxide pneumoperitoneum, 2.6 +/- 1.2 during, and 1.9 +/- 1.4 mmHg after termination of pneumoperitoneum. PaCO2 and pH during pneumoperitoneum were 35 +/- 1.7 mmHg and 7.41 +/- 0.02, respectively. There were no significant differences in either mean PaCO2--PetCO2 or PaCO2 and pH during various phases of laparoscopy. CONCLUSIONS: Capnography is adequate to guide ventilation during laparoscopic surgery in pregnant patients. Respiratory acidosis did not occur when PetCO2 was maintained at 32 mmHg during carbon dioxide pneumoperitoneum.     

腹腔镜下前列腺癌根治术中呼气末CO2分压的变化及意义

目的观察腹腔镜前列腺癌根治术中动脉血CO2分压（PaCO2）与呼气末CO2分压（PetCO2）差值Pa-ETCO2变化及其临床意义。方法腹腔镜前列腺癌根治术患者28例，于气管插管全身麻醉下完成手术，术中PETCO2维持在30～35mmHg左右，分别在麻醉后（T0），气腹第30min（T1），60min（T2），120min（T3），180min（T4）取桡动脉血行血气分析测PaCO2，据监测的PETCO2及血气分析获得的PaCO2，计算每个时间点的Pa-ETCO2。结果气腹后各时间点PaCO2，MBP，PPEAK，Pa-ETCO2明显增高（P〈0．05），人工气腹60min后，Pa-ETCO2发生显著变化（P〈0．01），部分患者出现CO2蓄积。气腹后PH值明显下降（P〈0．01）。结论腹腔镜前列腺癌根治术中人工气腹60min后PETCO2不能真实反映PaCO2，当PETCO2维持在30-35mmHg时应监测PaCO2避免发生高碳酸血症。     

"Low-pressure" laparoscopic cholecystectomy in high risk patients (ASA III and IV): our experience

The insufflation pressure used for laparoscopic cholecystectomy is usually 12-15 mm Hg, and a pneumoperitoneum with carbon dioxide has a significant effect on both cardiovascular and respiratory function. These effects are transient in young, healthy patients, but may be dangerous in ASA III and IV patients with a poor cardiac reserve. This study was designed to assess the feasibility of performing laparoscopic cholecystectomy at 6.5-8 mm Hg insufflation pressure in "high-risk" patients. Thirteen patients, 10 ASA III and 3 ASA IV, with cholelithiasis, were included in this study The insufflation pressure was 6.5-8 mm Hg, with a 10 degrees anti-Trendelenburg position. The cardiovascular and blood gas variables studied were: mean arterial blood pressure, heart rate, respiratory rate, and end-tidal CO2 pressure. The authors reported no conversions and no intra- or postoperative complications. During insufflation heart rate and mean arterial blood pressure increased minimally if compared with laparoscopic cholecystectomy at 12-15 mm Hg. Pa CO2 increased after insufflation (+5 mm Hg), and the end-tidal CO2 pressure gradient was moderate (3.5 mm Hg) and unchanged during surgery. A low-pressure pneumoperitoneum is feasible for laparoscopic cholecystectomy and minimizes the adverse haemodynamic effects of peritoneal insufflation.     

The effects of low-pressure carbon dioxide pneumoperitoneum on cerebral oxygenation and cerebral blood volume in children

We examined the effects of low-pressure carbon dioxide pneumoperitoneum on regional cerebral oxygen saturation (ScO(2)) and cerebral blood volume (CBV) in children. Fifteen children, ASA I--III, scheduled for laparoscopic fundoplication, were investigated in the head-up position (10) and ventilated to a baseline end-tidal CO(2) (PETCO(2)) between 25 and 33 mm Hg. Ventilatory settings remained unchanged during the operation. ScO(2) and CBV were assessed with near-infrared spectroscopy and recorded together with end-tidal and arterial carbon dioxide (PaCO(2)) at 5 time points: before insufflation, 30, 60, and 90 min after the start of CO(2) insufflation, and 10 min after desufflation. The intraabdominal pressure was kept between 5 and 8 mm Hg. During insufflation, PETCO(2) increased from 30.0 plus minus 2.8 to 38.3 plus minus 5.1 mm Hg (P < 0.001) and PaCO(2) increased from 32.0 plus minus 4.7 to 40.4 plus minus 5.9 mm Hg (P < 0.001). ScO(2) increased by 15.7% plus minus 8.8% (from 61 plus minus 9 to 70 plus minus 9 arbitrary units ) (P < 0.001). CBV increased by 4.6% plus minus 8.8% (from 123 plus minus 66 to 128 plus minus 66 arbitrary units [P = 0.048]). After desufflation, PETCO(2) and PaCO(2) decreased, but did not return to preinsufflation values. ScO(2) and CBV also decreased after desufflation. In conclusion, hyperventilation and the head-up position before CO(2) insufflation are not sufficient to prevent the CO(2)-mediated cerebral hemodynamic effects of low-pressure pneumoperitoneum (5--8 mm Hg) in children. IMPLICATIONS: Peritoneal CO(2) absorption during laparoscopic surgery causes hypercapnia and CO(2)-mediated cerebral hemodynamic effects. Hyperventilation and the head-up position before CO(2) insufflation is not sufficient to counteract these effects of low-pressure pneumoperitoneum (5--8 mm Hg) in children.     

Preserved CO(2) reactivity and increase in middle cerebral arterial blood flow velocity during laparoscopic surgery in children.

In adult patients, the creation of pneumoperitoneum (PP) by means of carbon dioxide (CO(2)) insufflation leads to an increase in cerebral blood flow velocity (CBFV), which is thought to be caused by hypercapnia. We evaluated whether PP leads to an increase of CBFV in children, and whether this increase is directly related to PP. The effects of PP on middle cerebral artery blood flow velocity were investigated in 12 children (mean age 3 yr, range 15-63 mo) undergoing laparoscopic herniorrhaphy under general anesthesia with sevoflurane and nitrous oxide/oxygen. CBFV was measured by using transcranial Doppler ultrasonography. During CO(2) insufflation, the end-tidal CO(2) concentration was kept constant by adjustment of ventilation by increasing minute volume. The CBFV increased significantly at an intraabdominal pressure of 12 mm Hg compared with baseline from 68 +/- 11 cm/s to 81 +/- 12 cm/s (P < 0.05). CO(2) reactivity remained in the normal range (4.0% +/- 1.9%/mm Hg) during PP. We conclude that the induction of PP leads to an increase in middle cerebral artery blood flow velocity in young children independent from hypercapnia, whereas CO(2) reactivity remains normal. IMPLICATIONS: Laparoscopic surgery is performed frequently in pediatric patients. Cerebral blood flow velocities increase during insufflation of the intraperitoneal cavity for minimally invasive surgery in children. The vasoreactivity as part of the cerebral autoregulation remains unaffected.     

Hemodynamics and gas exchange during carbon dioxide insufflation for totally endoscopic coronary artery bypass grafting

BACKGROUND: In addition to single-lung ventilation (SLV), positive-pressure CO2 insufflation is mandatory for totally endoscopic coronary artery bypass grafting. Studies on the effects of unilateral CO2 insufflation on hemodynamics produced controversial results, and bilateral insufflation has not been studied to our knowledge. The present study sought to investigate hemodynamics and gas exchange during unilateral and bilateral CO2 insufflation in patients who underwent totally endoscopic coronary artery bypass grafting. METHODS: Eleven hemodynamic and gas exchange variables were monitored during 22 totally endoscopic coronary artery bypass grafting procedures with unilateral (n = 17) or bilateral (n = 5) CO2 insufflation at a pressure of 10 to 12 mm Hg. Data were obtained at baseline with double-lung ventilation, after institution of SLV, during insufflation, after cardiopulmonary bypass during SLV, and after return to double-lung ventilation. RESULTS: Arterial oxygen tension decreased significantly during SLV, whereas the peak inspiratory pressure increased. In addition, central venous pressure and heart rate increased significantly during insufflation, but mean arterial pressure remained unchanged. Although the end-tidal CO2 pressure did not change, arterial carbon dioxide tension increased progressively to a maximum of 44.6 +/- 5.9 mm Hg during unilateral insufflation, and 55.7 +/- 14.6 mm Hg during bilateral insufflation (p < 0.05 versus baseline and between groups). Mixed venous oxygen saturation declined during SLV regardless of CO2 insufflation and recovered to baseline once double-lung ventilation was restarted. Left and right ventricular ejection fractions remained unaltered. No patient required inotropic or vasopressor support. CONCLUSIONS: Carbon dioxide insufflation for totally endoscopic coronary artery bypass grafting with SLV had no adverse effects on hemodynamics. In contrast to a moderate increase of arterial carbon dioxide tension during unilateral insufflation, markedly elevated arterial carbon dioxide tension levels remain a cause of concern during bilateral insufflation.     

The accuracy of transcutaneous carbon dioxide monitoring during laparoscopic surgery

BACKGROUND: Laparoscopic procedures are considered relatively low-invasive. However, there exists a small but important risk of developing complications related to carbon dioxide (CO2) insufflation. End-tidal CO2 (PetCO2) monitoring may not be a sufficient guide to adjust pulmonary ventilation during laparoscopic surgery, and arterial CO2 (PaCO2) monitoring is not always indicated. We evaluated the accuracy and feasibility of transcutaneous CO2 (PtcCO2) monitoring during laparoscopic surgery. METHODS: Thirty adult patients undergoing abdominal or gynecological laparoscopic surgery were studied. PtcCO2, PaCO2 and PetCO2 were measured before laparoscopy, and 30 and 60 minutes after beginning of CO2 insufflation. PtcCO2 and PaCO2 were also measured in the recovery room under spontaneous respiration. RESULTS: During operation, the PtcCO2 values demonstrated a high degree of correlation with PaCO2 (r = 0.92), and PetCO2 values also demonstrated generally a good correlation with PaCO2 (r = 0.85). The PtcCO2 PaCO2 gradient was -0.6 +/- 2.2 mmHg, while the PetCO2-PaCO2 gradient was -3.9 +/- 2.7 mmHg. In the recovery room, PtcCO2 values still demonstrated a high correlation with PaCO2 (r = 0.91). CONCLUSIONS: The transcutaneous devices provide an effective method for non-invasive monitoring of PCO2 in situations where continuous monitoring of CO2 levels is desired such as peri-operative period of laparoscopic surgery.     

Increased Insufflation Pressure Enhances the Development of Liver Metastasis in a Mouse Laparoscopy Model

Despite the widespread use of laparoscopic techniques for colorectal cancer surgery, little is known about the potential risk of liver metastasis following CO2 pneumoperitoneum. We investigated the effect of different insufflation pressures and durations of CO2 pneumoperitoneum on the growth of liver metastasis in a mouse model. Six- to 7-week old male BALB/C mice were intraportally inoculated with 2×104 Colon 26 cells and randomly allocated to receive either CO2 pneumoperitoneum at different pressures (5 mmHg, 10 mmHg, or 15 mmHg), xiphoid-pubic laparotomy, or no treatment other than tumor cell inoculation. Mice undergoing pneumoperitoneum or laparotomy were then subdivided by the duration of treatment (30 minutes or 60 minutes). Cancer nodules on the liver surface from a total of 122 mice were evaluated on the 14th postoperative day. Similar to full laparotomy, CO2 pneumoperitoneum at 10 mmHg and 15 mmHg for 60 minutes, and pneumoperitoneum at 15 mmHg for 30 minutes significantly promoted the growth of cancer nodules on the liver surface. Enhancement of tumor growth was influenced by increased insufflation pressures (p < 0.05) rather than the prolonged length of pneumoperitoneum (p = 0.53) without significant interaction (p = 0.49). These results suggest that an increased insufflation pressure promotes the growth of liver metastases as well as laparotomy in this animal model.     

Hemodynamic effects of carbon dioxide insufflation during endoscopic vein harvesting

BACKGROUND: A prospective study was performed assessing the hemodynamic effects of carbon dioxide (CO2) insufflation during endoscopic vein harvesting (EVH) using the Guidant Vasoview Uniport system. METHODS: Five hemodynamic and respiratory parameters (end-tidal carbon dioxide, arterial partial pressure of carbon dioxide, mean arterial pressure, mean pulmonary arterial pressure, and cardiac output), were measured in 100 consecutive patients undergoing EVH with CO2 insufflation. Data were obtained prior to commencement of EVH, 15 minutes after commencement, and 5 minutes after completion of the vein harvesting. RESULTS: No adverse hemodynamic effects were observed during CO2 insufflation. Specifically, average mean arterial pressure went from 88.77+/-9.64 to 89.13+/-8.60 to 88.24+/-8.71 mm Hg before, during, and after endoscopic vein harvesting (p = 0.291). Likewise, average mean pulmonary artery pressures were 19.76+/-4.75, 20.05+/-4.48, and 20.05+/-4.62 mm Hg (p = 0.547); and average cardiac output was 4.25+/-0.74, 4.22+/-0.73, and 4.23+/-0.69 L/min (p = 0.109) at those three intervals. Additionally, there was no evidence of significant systemic absorption of CO2 as reflected in average arterial PCO2, which remained steady at 37.42+/-5.19, 37.51+/-4.59, and 38.10+/-4.80 mm Hg (p = 0.217); and average end-tidal CO2, which was 32.10+/-3.66, 32.50+/-3.47, and 32.38+/-3.33 mm Hg (p = 0.335). In a subset of 20 patients with elevated pulmonary arterial pressure (more than 32 mm Hg), there was also no significant change in any of the parameters. CONCLUSIONS: Carbon dioxide insufflation during EVH leads to no adverse hemodynamic consequences or systemic CO2 absorption. The technique appears to be safe and well tolerated.     

腹膜后腹腔镜手术CO_2气腹时肾素-血管紧张素-醛固酮系统的变化

目的:动态监测腹膜后腹腔镜手术CO2气腹时不同时段肾素(renin,REN)、血管紧张素Ⅱ(angiotensin-Ⅱ,AT-Ⅱ)及醛固酮(aldosterone,ALD)的变化。方法:选择行泌尿外科腹膜后腹腔镜手术的患者20例,分别抽取CO2气腹前10min(T1)、气腹中30min(T2)、气腹中60min(T3)及气腹后60min(T4)各时段静脉血,运用放射免疫法测定血清REN、AT-Ⅱ及ALD含量。结果:REN、AT-Ⅱ及ALD在腹膜后腹腔镜手术CO2气腹的不同时段均有改变,各激素不同时段差异均有统计学意义(P0.001),表现为T3T2T4T1,T4时各激素水平与T1差异无统计学意义(P0.05)。结论:腹膜后腹腔镜CO2气腹对肾素-血管紧张素-醛固酮系统有一定影响,但气腹撤除后,可较快恢复正常。     

Intraabdominal Carbon Dioxide Insufflation in the Pregnant Ewe: Uterine Blood Flow, Intraamniotic Pressure, and Cardiopulmonary Effects

Background: Laparoscopic surgical procedures are being performed in pregnant women with increasing frequency. Maternal-fetal physiologic changes occurring during intraabdominal carbon dioxide insufflation are poorly understood, and maternal-fetal safety is of concern during carbon dioxide pneumoperitoneum. A previous pilot study using end-tidal carbon dioxide-guided ventilation resulted in maternal and fetal acidosis and tachycardia during carbon dioxide pneumoperitoneum. Using serial arterial PCO2 to guide ventilation, this study was designed to evaluate maternal-fetal cardiopulmonary status, uterine blood flow, and the intraamniotic pressure effects of intraabdominal carbon dioxide insufflation in singleton pregnant ewes between 120 and 135 days of gestation.

Methods: In a prospective randomized cross-over study, nine ewes were to receive either abdominal insufflation with carbon dioxide to an intraabdominal pressure of 15 mmHg (n = 9; insufflation group) or receive no insufflation (n = 9; control group). Anesthesia was induced with thiopental and maintained with end-tidal halothane (1 to 1.5 minimum alveolar concentration/100% oxygen). Mechanical ventilation was guided by serial maternal arterial blood gas analysis to maintain PaCO2 between 35 and 40 mmHg. Data from insufflated animals were collected during insufflation (60 min) and after desufflation (30 min). Control group data were collected and matched to similar time intervals for 90 min. Ewes were allowed to recover, and after a rest period (48 h) they were entered in the cross-over study.

Results: During insufflation there was a significant increase (P <0.05) in maternal PaCO2 to end-tidal carbon dioxide gradient and minute ventilation, with concomitant decreases in maternal end-tidal carbon dioxide and PaO2. Intraamniotic pressure increased significantly during insufflation. No significant changes were observed in maternal hemodynamic variables, fetal variables, or in uterine blood flow during the study. There were no fetal deaths or preterm labor in any of the animals during the experiment.     

Haemodynamic changes during low-pressure carbon dioxide pneumoperitoneum in young children

BACKGROUND: Both mechanical and pharmacological effects may contribute to the haemodynamic consequences of carbon dioxide (CO2) pneumoperitoneum. The aim of the present study was to evaluate the haemodynamic effects of low-pressure pneumoperitoneum [intra-abdominal pressure (IAP) 5 mmHg] in young children (< 3 years). METHODS: Thirteen children, aged 6-36 months, ASA physical status I-III, who were scheduled for laparoscopic fundoplication for gastro-oesophageal reflux were investigated in the head-up position (10 degrees ). Noninvasive thoracic electrical bioimpedance cardiac index (CI), stroke volume index (SVI), heart rate (HR), mean arterial pressure (MAP) and peak inspiratory pressure (PIP) were recorded, together with PetCO2 and PaCO2 at five time points: before insufflation, 20, 35 and 70 min after start of CO2 insufflation and 12 min after desufflation. During insufflation, minute ventilation was not adjusted and the IAP was maintained at 5 mmHg. RESULTS: During insufflation, PetCO2 increased from 29 +/- 4 to 37 +/- 5 mmHg (P < 0.001) and PaCO2 increased from 31 +/- 4 to 39 +/- 5 mmHg (P < 0.01). CI increased from 2.39 +/- 0.86 to 2.92 +/- 0.94 l x min-1 x m2 (P < 0.01), HR increased from 108 +/- 10 to 126 +/- 22 b x min-1 (P < 0.01), MAP increased from 52 +/- 10 to 63 +/- 9 (P < 0.05) and PIP increased from 16 +/- 3 to 18 +/- 3 cm H2O (P < 0.001). There were no changes in SVI and arterial oxygen saturation. CONCLUSIONS: We conclude that low-pressure CO2 pneumoperitoneum (with IAPs not exceeding 5 mmHg) for laparoscopic fundoplication in infants and children does not decrease their cardiac index.     

Effects of carbon dioxide pneumoperitoneum on cerebral hemodynamics in pigs.

Previous studies have shown that laparoscopic interventions are associated with increases in intracranial pressure. However, the consequences on cerebral blood flow (CBF) are unknown. This study investigates the effects of carbon dioxide (CO2) pneumoperitoneum on CBF in pigs. Ten pigs (weight, 20-26 kg) were anesthetized with 1.4% isoflurane and fentanyl (1 microg/kg per minute). Mechanical ventilation (fraction of inspired oxygen = 0.4) was set to maintain normocapnia (end-tidal CO2 tension = 35 mm Hg). Arterial and central venous catheters were placed for measurement of mean arterial blood pressure and central venous pressure. Bilateral internal carotid artery blood flow was measured using two transient time flow probes placed around both carotid arteries (with ligated external carotid arteries). Cortical and subcortical cerebral blood flow was measured using laser Doppler flowmetry. Sagittal sinus pressure was measured via a superior sagittal sinus catheter. After baseline measurements, the peritoneal cavity of the animals was insufflated with CO2 to achieve an intraabdominal pressure of 12-mm Hg. After 10 minutes of stable CO2, pneumoperitoneum measurements were repeated. Increases in central venous pressure (6.3 +/- 2.1 to 11.1 +/- 3.0 mm Hg) and sagittal sinus pressure (8.0 +/- 2.8 to 11.9 +/- 3.0 mm Hg) were noted during CO2 pneumoperitoneum (P < .05). Bilateral internal carotid artery blood flow (46.0 +/- 7.4 vs 47.7 +/- 7.1 mL/100g per minute), cortical CBF (263 +/- 115 vs 259 +/- 158 tissue perfusion units), and subcortical CBF (131 +/- 145 vs 133 +/- 149 tissue perfusion units) did not change during CO2 pneumoperitoneum. The current data show that CO2 pneumoperitoneum increases sagittal sinus pressure without changing CBF. Increases in sagittal sinus pressure are likely related to decreases in cerebral venous drainage caused by increases in intraabdominal pressure.     

Effects of intraperitoneal and extraperitoneal carbon dioxide insufflation on blood gases during the perioperative period

The aim of this study was to evaluate the effects of intraperitoneal and extraperitoneal CO2 insufflation on blood gases during and after laparoscopic surgery. Forty patients were included in this study. Twenty patients underwent elective laparoscopic cholecystectomy with intraperitoneal insufflation (intraperitoneal group) and 20 patients underwent laparoscopic inguinal hernia repair with extraperitoneal insufflation (extraperitoneal group). Arterial blood gases were analyzed at four points: 10 minutes after induction, 10 minutes after insufflation, 10 minutes after desufflation, and 30 minutes after the operation in the recovery room. PaCO2 values in the intraperitoneal group at the four points were 36.8 +/- 4, 39.6 +/- 5.9, 40.7 +/- 4.4, and 42.3 +/- 4.8 mm Hg; in the extraperitoneal group, 35.8 +/- 3.9, 37.4 +/- 4, 42.8 +/- 6.6, and 46.2 +/- 5.9 mm Hg. In the extraperitoneal group, there was a significant increase in postoperative PaCO2 compared to the desufflation PaCO2. In our study, extraperitoneal CO2 insufflation caused increases in PaCO2 values that started perioperatively and continued in the postoperative period.     

腹腔镜结直肠癌手术的麻醉管理

目的总结腹腔镜结直肠癌手术麻醉管理的经验。方法回顾性分析2007年10月~2009年6月178例腹腔镜下结直肠癌手术的麻醉资料,其中结肠癌根治手术76例,直肠癌根治手术102例,98例(55.1%)合并一种以上的全身性疾病。均采用气管内插管全身麻醉,术中监测无创血压(blood pressure,BP)、心率(heart rate,HR)、脉搏血氧饱和度(saturation of pulse oxygen,SpO2)、呼气末CO2分压(end-tidal carbon dioxide pressure,PETCO2)。结果气腹后10min平均动脉压(mean arterial pressure,MAP)、HR、PETCO2较气腹前显著性升高,经处理,气腹后30min MAP、HR明显降低,PETCO2无明显升高。术中130例(73.0%)使用一种以上的血管活性药,61例(34.3%)使用2种以上的血管活性药。132例在手术间或麻醉恢复室拔除气管导管,停止麻醉至拔除气管导管时间(39±25)min(6~140min),恢复室停留时间(71±36)min(25~209min)。46例(25.8%)带气管导管送入ICU病房。结论术前全面评估病人,完善围术期监测,加强术中管理,及时纠正处理合并症,腹腔镜结直肠癌手术患者的麻醉是安全的。     

Intraperitoneal carbon dioxide insufflation and cardiopulmonary functions. Laparoscopic cholecystectomy in pigs.

We studied the effects of laparoscopic cholecystectomy on respiratory and hemodynamic function in eight adult pigs. Minute ventilation was adjusted to normalize baseline arterial blood gases, then fixed throughout carbon dioxide insufflation. A metabolic measurement cart recorded total CO2 excretion, oxygen consumption, and minute ventilation. Carbon dioxide pneumoperitoneum was maintained at a constant pressure of 15 mm Hg as cholecystectomy was performed. After 1 hour of insufflation, CO2 excretion increased from 115 +/- 10 mL/min to 149 +/- 9 mL/min but O2 consumption remained unchanged. The PaCO2 increased from 35 +/- 2 mm Hg to 49 +/- 3 mm Hg and arterial pH fell from 7.47 +/- 0.02 to 7.35 +/- 0.03. Systemic and pulmonary hypertension occurred and stroke volume dropped from 35.5 +/- 3.5 mL to 28.6 +/- 2.2 mL with compensatory tachycardia. Right atrial pressure remained unchanged as inferior vena cava pressure increased to reflect the intraperitoneal pressure. We conclude that CO2 pneumoperitoneum resulted in significant transperitoneal CO2 absorption, with secondary hypercapnia and acidemia. The accumulation of CO2 was also associated with an increase in systemic and pulmonary arterial pressure. Heart rate increased to compensate for the decreased stroke volume to maintain cardiac output.     

Liver blood flow changes during laparoscopic surgery in pigs

BACKGROUND: Physiological effects caused by abdominal insufflation in the course of laparoscopic surgery are partially unknown. The purpose of the present study was to determine if indocyanine green (ICG) pharmacokinetic parameters, as an index of hepatic blood flow, change during laparoscopic surgery in the presence of a CO2 pneumoperitoneum. This effect could cause important alterations in the kinetics of anesthetic drugs. METHODS: Eighteen female pigs were anaesthetized under constant ventilation and randomly assigned to three groups undergoing insufflation with CO2 (I), laparoscopic oophorectomy with CO2 pneumoperitoneum (LS), or oophorectomy by open surgery (OS). CO2 pneumoperitoneum was performed at 14 mmHg. ICG (1 mg/kg) was injected into a marginal vein on two separate occasions: 30 min before and 30 min after the start of insufflation or surgery. Blood was sampled from the carotid artery at time intervals after the injection of ICG and after pharmacokinetic parameters were obtained by a computer program. RESULTS: The area under the curve (AUC0-infinity) indicated important dysfunctions in ICG availability in all three groups of animals, with significant increases of 104%, 82%, and 48% for groups I, LS, and OS, respectively. The ICG apparent half-life did not significantly change in group OS, but it rose in groups I (+17%) and LS (+28%). ICG clearance was significantly reduced by 32% in group OS and to a larger extent in groups I and LS (-45% and -46%, respectively). CONCLUSION: These findings confirm the contribution of CO2 pneumoperitoneum to decreased liver blood flow during laparoscopic surgery.     

Laparoscopic cholecystectomy for patients with chronic obstructive pulmonary disease

PURPOSE: Laparoscopic cholecystectomy (LC) is accepted as a "gold standard" for treating most gallbladder diseases because it is superior to the open method, causes less postoperative pulmonary dysfunction, and promotes earlier postoperative recovery. The laparoscopically associated adverse effects of a carbon dioxide (CO(2)) pneumoperitoneum, however, such as hypercarbia and arterial acidosis, are more pronounced in patients with chronic obstructive pulmonary disease (COPD). The clinical results of LC for patients with COPD are analyzed in this study. METHODS: Twenty-two patients with COPD (group 1) and undergoing LC were compared with 25 control patients without COPD and also undergoing LC (group 2). Patient demographics, intraoperative end-tidal CO(2) (both before and after CO(2) insufflation), and clinical outcome, including surgical duration, length of postoperative hospital stay, and any associated complications, were analyzed. RESULTS: The procedure of one group 1 patient was converted to the open method, and this patient was excluded from the study. Comprising the COPD group were 20 patients with mild COPD and one patient with moderate COPD. With similar settings of tidal volume and ventilation rate for the two groups, the measured end-tidal CO(2) value was significantly greater for group 1 than for group 2 patients after the creation of a CO(2) pneumoperitoneum (34.2 +/- 2.7 vs. 30.7 +/- 3.6 mm Hg; P =.012). The duration of surgery was similar for groups 1 and 2 (88.9 +/- 36.0 vs. 83.2 +/- 38.3 minutes), as was the duration of the postoperative hospital stay (3.3 +/- 1.6 vs. 3.4 +/- 2.2 days). No pulmonary complications were noted for any of the patients. CONCLUSIONS: LC can be safely performed in COPD patients with mild or even a moderate degree of airway obstruction. Intraoperative CO(2) retention did not complicate the postoperative recovery in terms of the complication rate or the duration of the postoperative hospital stay.     

新生儿腹腔镜麻醉中呼吸循环功能的变化

目的：观察新生儿腹腔镜中，CO2气腹对呼吸循环系统功能的影响。方法：50例腹腔镜幽门环肌切开术的新生儿均行硬膜外麻醉辅以浅全麻，术中VT10ml/kg，调整呼吸频率使PETCO2在30－40mmHg范围内，注气前、气腹中、注气毕记录各时点的呼吸循环动力学指标。结果：气腹后，心率、MAP、PETCO2、最大吸气压（PIP）、PaCO2与注气前基础值相比均明显增高，pH值明显下降，SaO2值没有显著性变化。PETCO2在术毕10分钟内转为基础值。结论：新生儿气腹可引起呼吸循环功能的改变，使用硬膜外麻醉行腹腔镜幽门环肌切开术安全可行。