Are there changes in leg vascular resistance during laparoscopic cholecystectomy with CO2 pneumoperitoneum?

Impact of pneumoperitoneum on intra-abdominal microcirculation blood flow: an experimental randomized controlled study of two insufflator models during transanal total mesorectal excision : An experimental randomized multi-arm trial with parallel treatment design

OBJECTIVE

To compare changes in microcirculation blood flow (MCBF) between pulsatile and continuous flow insufflation. Transanal total mesorectal excision (TaTME) was developed to improve the quality of the resection in rectal cancer surgery. The AirSeal IFS® insufflator facilitates the pelvic dissection, although evidence on the effects that continuous flow insufflation has on MCBF is scarce.

METHODS

Thirty-two pigs were randomly assigned to undergo a two-team TaTME procedure with continuous (n = 16) or pulsatile insufflation (n = 16). Each group was stratified according to two different pressure levels in both the abdominal and the transanal fields, 10 mmHg or 14 mmHg. A generalized estimating equations (GEE) model was used.

RESULTS

At an intra-abdominal pressure (IAP) of 10 mmHg, continuous insufflation was associated with a significantly lower MCBF reduction in colon mucosa [13% (IQR 11;14) vs. 21% (IQR 17;24) at 60 min], colon serosa [14% (IQR 9.2;18) vs. 25% (IQR 22;30) at 60 min], jejunal mucosa [13% (IQR 11;14) vs. 20% (IQR 20;22) at 60 min], renal cortex [18% (IQR 15;20) vs. 26% (IQR 26;29) at 60 min], and renal medulla [15% (IQR 11;20) vs. 20% (IQR 19;21) at 90 min]. At an IAP of 14 mmHg, MCBF in colon mucosa decreased 23% (IQR 14;27) in the continuous group and 28% (IQR 26;31) in the pulsatile group (p = 0.034).

CONCLUSION

TaTME using continuous flow insufflation was associated with a lower MCBF reduction in colon mucosa and serosa, jejunal mucosa, renal cortex, and renal medulla compared to pulsatile insufflation.

The effect of intermittent intraabdominal pressure elevations and low cardiac output on the femoral to carotid arterial blood pressure difference in piglets

BACKGROUND

Our previous work in a laparoscopic setting in piglets revealed that the systolic femoral artery pressure was approximately 5 % higher than its carotid counterpart, whereas the mean and diastolic values showed no significant difference. This remained idem when the intraabdominal pressure (IAP) was gradually increased. In this study, we aimed to investigate the effect of (1) intermittent IAP elevations and (2) a low cardiac output (CO) on the blood pressure (BP) difference cranially (carotid artery) and caudally (femoral artery) of a capnoperitoneum (ΔP = P _{a fem}-P _{a carot}).

METHODS

A total of twenty-two piglets (mean body weight 11.0 kg; range 8.9-13.3 kg) were studied. Of these, 14 underwent intermittent IAP elevations at 8 and 16 mmHg, and ΔP was measured. In another 8 piglets, a model of reduced CO was created by introducing an air embolism (2 ml/kg over 30 s) in the inferior caval vein (VCI) at 12 mmHg IAP to further assess the influence of this variable on ΔP.

RESULTS

Systolic ΔP remained at a mean of 5.6 mmHg and was not significantly affected by insufflation or exsufflation up to an IAP of 16 mmHg. Diastolic and mean values showed no differences between P _{a carot} and P _{a fem}. P _{a fem, systol} remained higher than its carotid counterpart as long as the cardiac index (CI) was above 1.5 l/min/m², but fell significantly below P _{a carot, systol} at a low CI. There was no CO-dependent effect on diastolic and mean ΔP. Repeated IAP elevations do not significantly influence ΔP.

CONCLUSIONS

Intermittent IAP elevations do not significantly influence ΔP. Despite of a CO-dependent inversion of systolic ΔP, mean BP measurements at the leg during laparoscopy remain representative even at low CO values.

Effect of Retroperitoneal Lavage with Normal Saline Containing Adrenaline on Carbon Dioxide Absorption in Patients Undergoing Retroperitoneal Laparoscopic Surgery

OBJECTIVE

To determine the effect of lavage with adrenaline solution on CO2 absorption during retroperitoneal laparoscopic surgery.

MATERIALS AND METHODS

Sixty patients scheduled to undergo retroperitoneal laparoscopic surgery were divided into an AD group (lavage with normal saline containing adrenaline [1:500,000], n = 30) and an NS group (lavage with normal saline only, n = 30). After the establishment of artificial pneumoperitoneum and before the start of the operation, the retroperitoneal space was irrigated with 300 mL of normal saline with or without adrenaline, depending on the group. The lavage fluid was aspirated after 3 minutes. Heart rate (HR), mean arterial pressure (MAP), blood oxygen saturation (SpO2), partial pressure of O2 (PaO2), partial pressure of CO2 (PaCO2), and end-tidal CO2 partial pressure (PETCO2) were recorded before the lavage (T0) and at 10, 30, 60, 90, and 120 minutes (T1-T5, respectively) after the lavage. The CO2 output (VCO2) was calculated, and the incidence of intraoperative arrhythmia and postoperative complications (e.g., headache, palpitations, irritation) was determined.

RESULTS

HR, MAP, SpO2, PaO2, PaCO2, PETCO2, and VCO2 at T0 did not significantly differ between the groups (P > .05). HR, PaCO2, PETCO2, and VCO2 at T1-T5 were lower in the AD group than in the NS group (P < .05). The incidence of intraoperative arrhythmia and postoperative complications was lower in the AD group than in the NS group (P < .05).

CONCLUSIONS

Lavage with normal saline containing adrenaline (1:500,000) reduced CO2 absorption during retroperitoneal laparoscopic surgery, prevented hypercapnia, and decreased intra- and postoperative complications.

Effect of transgastric natural orifice transluminal endoscopic surgery peritoneoscopy on abdominal organ microcirculation: an experimental controlled study

BACKGROUND AND AIMS

On-demand insufflation during endoscopic peritoneoscopy causes wide variations in intra-abdominal pressure. Its effects on splanchnic microcirculation may differ from those of steady intra-abdominal pressure, because pressure characteristics affect crucial intravascular hemodynamic forces--pressure and shear--adapting flow to local metabolic needs. Our aim was to assess the effect of natural orifice transluminal endoscopic surgery (NOTES) peritoneoscopy on splanchnic microcirculatory blood flow.

METHODS

Twenty-one swine were randomized to the following: cholecystectomy by transgastric NOTES (n = 8), cholecystectomy by standard laparoscopy (Lap) (n = 8), and a sham group (n = 5). During NOTES, CO2 was manually insufflated with a maximum allowed pressure of 30 mm Hg. In the Lap group, intra-abdominal pressure was maintained at 14 mm Hg. Systemic hemodynamics were measured, and microcirculatory blood flow was quantified by using colored microspheres.

RESULTS

Mean intra-abdominal pressure was lower in NOTES than in the Lap group (P = .038). In both groups, cardiac index and preload remained unchanged, whereas systemic vascular resistances increased over time, with a lesser increase in the Lap group (2-way analysis of variance; P = .041). In pneumoperitoneum groups, microcirculatory blood flow decreased similarly in the renal medulla, stomach, small bowel, colon, and mesocolon by 30%, 45%, 34%, 32%, and 37%, respectively. In NOTES, there was a greater microcirculatory blood flow decrease in the renal cortex (NOTES 41% vs Lap 35%; P = .044) and mesentery (NOTES 44% vs Lap 38%; P = .041).

CONCLUSIONS

These findings suggest that both types of pneumoperitoneum have similar physiologic effects on microcirculatory blood flow. However, on-demand pneumoperitoneum (NOTES group) caused a greater microcirculatory blood flow decrease in areas with low metabolic needs, redistributing blood flow toward metabolically active areas.

What is the evidence for the use of low-pressure pneumoperitoneum? A systematic review

Background

Laparoscopic surgery has several advantages when compared to open surgery, including faster postoperative recovery and lower pain scores. However, for laparoscopy, a pneumoperitoneum is required to create workspace between the abdominal wall and intraabdominal organs. Increased intraabdominal pressure may also have negative implications on cardiovascular, pulmonary, and intraabdominal organ functionings. To overcome these negative consequences, several trials have been performed comparing low- versus standard-pressure pneumoperitoneum.

Methods

A systematic review of all randomized controlled clinical trials and observational studies comparing low- versus standard-pressure pneumoperitoneum.

Results and conclusions

Quality assessment showed that the overall quality of evidence was moderate to low. Postoperative pain scores were reduced by the use of low-pressure pneumoperitoneum. With appropriate perioperative measures, the use of low-pressure pneumoperitoneum does not seem to have clinical advantages as compared to standard pressure on cardiac and pulmonary function. Although there are indications that low-pressure pneumoperitoneum is associated with less liver and kidney injury when compared to standard-pressure pneumoperitoneum, this does not seem to have clinical implications for healthy individuals. The influence of low-pressure pneumoperitoneum on adhesion formation, anastomosis healing, tumor metastasis, intraocular and intracerebral pressure, and thromboembolic complications remains uncertain, as no human clinical trials have been performed. The influence of pressure on surgical conditions and safety has not been established to date. In conclusion, the most important benefit of low-pressure pneumoperitoneum is lower postoperative pain scores, supported by a moderate quality of evidence. However, the quality of surgical conditions and safety of the use of low-pressure pneumoperitoneum need to be established, as are the values and preferences of physicians and patients regarding the potential benefits and risks. Therefore, the recommendation to use low-pressure pneumoperitoneum during laparoscopy is weak, and more studies are required.

Comparison of femoral and carotid blood pressure during laparoscopy in piglets

PURPOSE

The impact of a capnoperitoneum on the known blood pressure (BP) difference of the upper and lower limb was studied in piglets.

METHODS

Eleven German Landrace piglets (body weight, 4.3-7.4 kg; mean body weight, 6.2 kg) were studied. Arterial lines were placed in the right carotid and right femoral artery for pressure monitoring. Intraabdominal pressure levels were increased in steps of 6 mm Hg up to 24 mm Hg.

RESULTS

We found that elevated intraabdominal pressures up to 24 mm Hg did not change the preexisting systolic BP difference between the carotid and femoral arteries. Systolic femoral artery pressure constantly remained 5% higher than its carotid counterpart. In addition, mean and diastolic values were not affected.

CONCLUSIONS

Arterial BP measurements recorded at the legs of piglets when abdominal pressure is increased by up to 24 mm Hg can be used for intraoperative assessment of systemic arterial BP.

High-intensity transient signals during laparoscopic surgery in children

BACKGROUND

Laparoscopic interventions in children gain increasing popularity. Pneumoperitoneum as applied during laparoscopic surgery can induce gas emboli formation, but it is unclear whether this is associated with cerebral embolic events. To investigate the hypothesis that pneumoperitoneum causes cerebral emboli in children, the number and intensity of high-intensity transient signals (HITS) detected using transcranial Doppler ultrasonography were assessed before and after induction of pneumoperitoneum.

METHODS

Twenty children were monitored during laparoscopic surgery. General anaesthesia was performed using sevoflurane and sufentanil or alfentanil. Pressure-controlled ventilation was adapted to maintain end-tidal Pco(2) (Pe'(co(2))) between 4.7 and 6.0 kPa. Baseline measurement of HITS rate, cerebral blood flow velocity, and mean arterial pressure (MAP) were recorded during steady-state anaesthesia before skin incision and during pneumoperitoneum with intra-abdominal pressure of 1.6-2.0 kPa applied using CO(2).

RESULTS

In 14 children (70%), HITS were detected during baseline and pneumoperitoneum. Three additional children (15%) developed HITS during pneumoperitoneum only and another three children (15%) presented no HITS during the investigation period. MAP and cerebral blood flow velocity increased with pneumoperitoneum.

CONCLUSIONS

HITS are present in 70% of paediatric surgical patients under balanced anaesthesia before surgical interventions. Pneumoperitoneum further increased the occurrence of HITS.