Adverse cardiovascular changes induced by positive pressure pneumoperitoneum. Possible solutions to a problem

Current status of laparoscopy for acute abdomen in Italy: a critical appraisal of 2012 clinical guidelines from two consecutive nationwide surveys with analysis of 271,323 cases over 5 years

BACKGROUND

Several authors have demonstrated the safety and feasibility of laparoscopy in selected cases of abdominal emergencies. The aim of the study was to analyse the current Italian practice on the use of laparoscopy in abdominal emergencies and to evaluate the impact of the 2012 national guidelines on the daily surgical activity.

METHODS

Two surveys (42 closed-ended questions) on the use of laparoscopy in acute abdomen were conducted nationwide with an online questionnaire, respectively, before (2010) and after (2014) the national guidelines publication. Data from two surveys were compared using Chi-square or Fisher's exact test, and data were considered significant when p < 0.05.

RESULTS

Two-hundred and one and 234 surgical units answered to the surveys in 2010 and 2014, respectively. Out of 144,310 and 127,013 overall surgical procedures, 23,407 and 20,102, respectively, were abdominal emergency operations. Respectively 24.74 % (in 2010) versus 30.27 % (in 2014) of these emergency procedures were approached laparoscopically, p = 0.42. The adoption of laparoscopy increased in all the considered clinical scenarios, with statistical significance in acute appendicitis (44 vs. 64.7 %; p = 0.004). The percentage of units approaching Hinchey III acute diverticulitis with laparoscopy in 26-75 % of cases (14.0 vs. 29.7 %; p = 0.009), those with >25 % of surgeons confident with laparoscopic approach to acute diverticulitis (29.9 vs. 54 %; p = 0.0009), the units with >50 % of surgeons confident with laparoscopic approach to acute appendicitis, cholecystitis and perforated duodenal ulcer, all significantly increased in the time frame. The majority of respondents declared that the 2012 national guidelines influenced their clinical practice.

CONCLUSIONS

The surveys showed an increasing use of laparoscopy for patients with abdominal emergencies. The 2012 national guidelines profoundly influenced the Italian surgical practice in the laparoscopic approach to the acute abdomen.

Physiopathology and clinical considerations of laparoscopic surgery in the elderly

OBJECTIVE

The marked improvements in medical technology and healthcare, lead an increasing number of elderly patients to take advantage of even complex surgical. Recently, laparoscopic surgery has been accepted as a minimally invasive treatment to reduce the morbidity after conventional surgery, and a number of studies have demonstrated the feasibility of laparoscopy with significant advantages also in the elderly. On the other side, the laparoscopic procedure has some drawbacks, including prolonged operation time and impact of carbon dioxide pneumoperitoneum on circulatory and respiratory dynamics. This paper will review the physiopathological implications of laparoscopy, as well as the current literature concerning the most common laparoscopic procedures that are increasingly performed in elderly patients.

MATERIALS AND METHODS

A systematic review of the current literature was performed using the search engines EMBASE and PubMed to identify all studies reporting the physiopathological implications of laparoscopy in the elderly. The MeSH search terms used were "laparoscopy in the elderly", "physiopathology of laparoscopy", and "pneumoperitoneum". Multiple combinations of the keywords and MeSH terms were used with particular reference to elderly patients.

RESULTS

Although laparoscopy is minimally invasive in its dissection techniques, the increased physiologic demands present particular challenges among elderly patients.

CONCLUSIONS

Laparoscopy and its safety in the elderly patients remains a challenge and the evaluation of this approach is therefore mandatory. Although many studies have demonstrated the applicability and advantages of the laparoscopy also in the geriatric population, with low rates of morbidity and mortality, in elderly patients undergoing general surgical procedures the physiologic demands of laparoscopy should be carefully considered.

Hemodynamic effect and safety of intermittent sequential pneumatic compression leg sleeves in patients with congestive heart failure

BACKGROUND

Pneumatic leg sleeves are widely used after prolonged operations for prevention of venous stasis. In healthy volunteers they increase cardiac function. We evaluated the hemodynamic effects and safety of intermittent sequential pneumatic compression (ISPC) leg sleeves in patients with chronic congestive heart failure (CHF).

METHODS AND RESULTS

We studied 19 patients with systolic left ventricular dysfunction and CHF. ISPC leg sleeves, each with 10 air cells, were operated by a computerized compressor, exerting 2 cycles/min. Hemodynamic and echocardiographic parameters were measured before, during, and after ISPC activation. The baseline mean left ventricular ejection fraction was 29 ± 9.2%, median 32%, range 10%-40%. Cardiac output (from 4.26 to 4.83 L/min; P = .008) and stroke volume (from 56.1 to 63.5 mL; P = .029) increased significantly after ISPC activation, without a reciprocal increase in heart rate, and declined after sleeve deactivation. Systemic vascular resistance (SVR) decreased significantly (from 1,520 to 1,216 dyne-s/cm5; P = .0005), and remained lower than the baseline level throughout the study. There was no detrimental effect on diastolic function and no adverse clinical events, despite increased pulmonary venous return.

CONCLUSIONS

ISPC leg sleeves in patients with chronic CHF do not exacerbate symptoms and transiently improve cardiac output through an increase in stroke volume and a reduction in SVR.

The physiological impact of intermittent sequential pneumatic compression (ISPC) leg sleeves on cardiac activity

BACKGROUND

Pneumatic sleeves are widely used in surgery to prevent venous stasis and to improve cardiac function. The aim of this study was to assess the underlying cardiovascular mechanism induced by the activation of intermittent sequential pneumatic compression (ISPC) in healthy volunteers.

METHODS

Twenty male subjects underwent transthoracic echocardiographic and tissue Doppler imaging evaluation before and during the activation ISPC devices. Each patient served as his own control.

RESULTS

Following ISPC activation, there were significant increases in cardiac output (from 5.1 to 5.5 L/min, P < .05) and stroke volume (from 72 to 78 mL, P < .002), as well as ejection fraction, the velocity-time integral of aortic flow, and fractional shortening of the left ventricle. There was no increase in heart rate. Tissue Doppler imaging was compatible with normal cardiac responses. Total peripheral resistance was significantly reduced during ISPC activation.

CONCLUSIONS

The activation of ISPC devices in normal volunteers augmented cardiac output because of increased preload as well as decreased afterload.

Systematic review of oxidative stress associated with pneumoperitoneum

Background

There have been several reports of ischaemic complications after routine laparoscopy. The aim of this review was to investigate the relationship between this oxidative stress and pneumoperitoneum.

Methods

Medline, Medline in-process, The Cochrane Library, PubMed and EMBASE were searched for papers on oxidative stress and pneumoperitoneum, from 1947 to March 2008 with no language restriction or restriction on trial design. Papers that did not investigate pneumoperitoneum as a causative factor, or did not report outcome measures related to oxidative stress, were excluded.

Results

A total of 73 relevant papers were identified: 36 animal studies, 21 human clinical trials, nine case reports, five review articles and two comments. Pneumoperitoneum causes a reduction in splanchnic blood flow, resulting in biochemical evidence of oxidative stress in a pressure- and time-dependent manner. There is evidence that the use of carbon dioxide for insufflation is contributory. Several measures proposed to minimize the oxidative stress have shown promise in animal studies, but few have been evaluated in the clinical setting.

Conclusion

There is an increasing body of evidence, mainly from animal studies, that pneumoperitoneum decreases splanchnic perfusion with resulting oxidative stress. It is now appropriate to investigate the clinical significance of pneumoperitoneum-associated oxidative stress.

Validation and reduction of the oxidative stress following laparoscopic operations: a prospective randomized controlled study

OBJECTIVE

To validate ischemia-reperfusion mechanism during laparoscopic cholecystectomy, and to assess the reduction of oxidative stress by an intermittent sequential pneumatic compression (ISPC) device.

SUMMARY BACKGROUND

Increased intraperitoneal pressure during laparoscopic operations may lead to decreased cardiac output and visceral perfusion, and possible ischemia-reperfusion effects. Using the ISPC device was shown to improve cardiac output and visceral perfusion during pneumoperitoneum (PP).

METHODS

Twenty patients undergoing elective laparoscopic cholecystectomy were enrolled in a randomized prospective controlled study and divided into 2 groups: 1) study group (10 patients), activation of ISPC together with creation of PP; and 2) control group, without ISPC. Lipid peroxidation and glutathione levels (as indicators of oxidative stress) as well as liver and renal function tests, were measured before and at the end of PP, and again at 30 minutes, 4 hours, and 24 hours afterward, together with hemodynamic and respiratory parameters.

RESULTS

There was no significant difference between both groups concerning liver enzymes and bilirubin, nor in hemodynamic parameters. In the control group, increased lipid peroxide levels were noted 4 hours after PP termination, in comparison to pre-PP levels (590.4-649.2 mmol/L, P = 0.002). In the study group (ISPC), such changes were not inspected. Decreased total glutathione levels were noted in the control group, 30 minutes following CO2 evacuation.

CONCLUSIONS

Our study validates the ischemia-reperfusion mechanism following laparoscopic surgery. The use of an ISPC device decreased the oxidative stress (secondary to relative ischemia-reperfusion insult) following PP, probably due to improved cardiac output and visceral perfusion.

A randomized controlled study evaluating the effects of the temperature of insufflated CO2 on core body temperature and blood gases (an experimental study)

BACKGROUND

Heated carbon dioxide (CO2) was used for pneumoperitoneum (Pp) to prevent hypothermia. This study aimed to investigate the relationship between the temperature of the insufflated CO2 and blood gases together with the core body temperature (CBT).

METHODS

A prospective controlled study was performed with 24 pigs weighing approximately 20 kg randomized into four groups of 6 pigs each. A pneumoperitoneum at 12 mmHg of pressure was applied for 60 min with the pig under general anesthesia. The CO2)temperature was 22 degrees C in group 1, 37 degrees C in group 2, and 7 degrees C in group 3. In the "sham" group, pneumoperitoneum was not applied. Arterial blood pH and partial pressure of CO2 (PaCO2) were analyzed before insufflation, every 15 min during the pneumoperitoneum, and 15 min after the desufflation. The CBT was recorded before the insufflation, every 20 min during pneumoperitoneum, and 20 min after the desufflation. Blood gas analyses and CBT records for the "sham" group were performed at the same intervals.

RESULTS

Arterial blood pH gradually decreased during pneumoperitoneum. At the 60th minute of pneumoperitoneum, a minimum decrease in arterial blood pH (0.04; p = 0.027) and a minimum increase in PaCO2 (3.67; p = 0.027) were recorded in group 3, whereas a maximum decrease in arterial blood pH (0.18; p = 0.027) and a maximum increase in PaCO2 (17.17; p = 0.027) were recorded in group 2. There was a significant negative correlation between PaCO2 and arterial blood pH in all the groups (r = -0.993; p < 0.01). The mean values of CBT decreases were statistically significant in all the groups: group 1 (p = 0.023), group 2 (p = 0.026), group 3 (p = 0.026), and "sham" group (p = 0.024).

CONCLUSIONS

The changes in PaCO2 were directly proportional and the changes in pH contrarily proportional to the temperature of the insufflated CO2. Significant differences in CBT decreases were found between the groups receiving heated gas and room temperature gas and the groups receiving heated gas and gas below room temperature.

Improving the adverse changes in cardiac autonomic nervous control during laparoscopic surgery, using an intermittent sequential pneumatic compression device

BACKGROUND

The creation of positive pressure pneumoperitoneum (PP) may lead to adverse cardiovascular effects during laparoscopic operations. It can also lead to increased sympathetic cardiac activity, that might have serious consequences. We hypothesized that by reversing the hemodynamic effects, the use of intermittent sequential pneumatic compression device (Lympha-press) on the lower extremities would lead to improved cardiac autonomic control.

METHODS

This was a prospective cohort study, in which patients served as their own control. Fifteen patients without cardiorespiratory disease undergoing elective laparoscopic cholecystectomy were enrolled prospectively. The activity of the cardiac autonomic nervous system was evaluated by using spectral analysis of heart rate variability, with the Del Mar Avionics 363 (Irvine, California), based on the fast Fourier transformation. The Lympha-press was manipulated several minutes after induction of PP. In each frequency band we measured and compared the power values during anesthesia against those of PP, as well as those of PP against those recorded during activation of Lympha-press.

RESULTS

Creation of PP caused increased sympathetic activity, as was manifested by increased power of the low frequency band. Manipulation of the Lympha-Press compression device caused increased parasympathetic activity, as was evident by significant increased power of the high frequency band in all patients.

CONCLUSIONS

Using an intermittent sequential pneumatic compression device during laparoscopic cholecystectomy may improve cardiac autonomic control by enhancing protective parasympathetic activity. That may have clinical significance, especially in patients suffering from cardiac disease, by improving heart rate variability and elevating the threshold of the occurrence of ventricular arrhythmia.

Decreased cardiac output in humans during laparoscopic antireflux surgery: direct measurements

OBJECTIVE

In a porcine model, we demonstrated that laparoscopic Nissen fundoplication causes a significant drop in cardiac output (30%) because it exposes both the peritoneal cavity and the mediastinum to CO(2) under pressure. To determine if this occurs in humans, we examined cardiovascular physiology during laparoscopic Nissen fundoplication. Because of invasiveness required in this pilot trial, only six patients were studied.

METHODS

The arterial blood pressure (via radial arterial catheter) and the pulmonary artery diastolic pressure and cardiac index (via pulmonary artery thermodilution catheter) were measured at seven points in time during each laparoscopic Nissen fundoplication.

RESULTS

The systolic blood pressure decreased in all patients, and the cardiac index decreased in all but one patient. The exception was a patient with Huntington disease, in whom the cardiac output did not decrease. In four of the five patients, the cardiac output was lowest during hiatal dissection, and in the fifth, it was lowest after reverse Trendelenburg positioning. No significant change in the pulmonary artery diastolic pressure was noted. All patients received adequate intravenous fluid replacement (average, 58 +/- 16 mL/kg) to support blood pressure. In one patient, with a particularly large paraesophageal hernia, profound hypotension (40/25 mm Hg) developed during the mediastinal phase of the procedure, and this patient required alpha-adrenergic support followed by laparotomy to eliminate a surgical cause (none found).

CONCLUSIONS

Although it is a tremendous advance for patients, laparoscopic Nissen fundoplication can be associated with a significant reduction in cardiac output and blood pressure. Surgeons and anesthesiologists must be alert to changes reflecting these decreases during procedures, which violate both the peritoneal cavity and the mediastinum. We propose careful hemodynamic monitoring during these procedures, especially in patients with coronary artery disease or significant left ventricular dysfunction.

Central and peripheral adverse hemodynamic changes during laparoscopic surgery and their reversal with a novel intermittent sequential pneumatic compression device

OBJECTIVE

To study the influence of a novel intermittent sequential pneumatic compression device (Lympha-press) on the adverse cardiac and peripheral hemodynamic changes induced by positive-pressure pneumoperitoneum (PPPn) in laparoscopic surgery.

SUMMARY BACKGROUND DATA

Creation of PPPn is known to cause adverse central and peripheral hemodynamic changes. An intrasubject observational study was undertaken to quantitate these adverse changes and to assess the influence of an intermittent sequential pneumatic compression system on these adverse hemodynamic changes during laparoscopic surgery with PPPn.

METHODS

The study involved 16 consecutive patients undergoing laparoscopic surgery with PPPn of 12 mmHg and 30 degrees head-up tilt position. The following peripheral hemodynamic recordings were made using Doppler ultrasound: peak systolic velocity (PSV), end diastolic velocity (EDV), and cross-sectional area of the femoral vein. Central monitoring included cardiac output and stroke volume by transesophageal Doppler, blood pressure, and pulse. The hemodynamic state based on these parameters was assessed before induction of PPPn with the anesthetized patient in the supine position, after induction of PPPn and head-up tilt position with Lympha-press off, and during PPPn and head-up tilt position with Lympha-press on, and after desufflation with the patient in the supine position under general anesthesia.

RESULTS

Positive-pressure pneumoperitoneum and the head-up tilt position resulted in a 33% reduction in PSV, a 21% reduction in EDV, and a 29% increase in cross-sectional area of the femoral vein. This was associated with a 20% reduction in cardiac output and an 18% reduction in stroke volume. Activation of Lympha-press during PPPn and the head-up tilt position resulted in a 129% increase in PSV and a 55% increase in EDV by 55%. It also increased the cardiac output by 27% and stroke volume by 16%, with no effect on cross-sectional area. Compared with the pre-PPPn stage, there was no difference in cardiac output or stroke volume, but the PSV was higher by 78% and the EDV by 32%. After abdominal desufflation in the supine position, the cardiac output and stroke volume were restored to the pre-PPPn level, but persistent and significant elevations were observed during the period of study in PSV, EDV, and cross-sectional area.

CONCLUSIONS

Significant and individually variable central and peripheral hemodynamic changes are encountered during laparoscopic surgery with PPPn and the head-up tilt position. These are reversed by intermittent sequential pneumatic compression using Lympha-press.

Hemodynamic and pulmonary changes during open, carbon dioxide pneumoperitoneum and abdominal wall-lifting cholecystectomy. A prospective, randomized study

BACKGROUND

Carbon dioxide (CO2) pneumoperitoneum effects are still controversial. The aim of this study was to investigate cardiopulmonary changes in patients subjected to different surgical procedures for cholecystectomy.

METHODS

In this study, 15 patients were assigned randomly to three groups according to the surgical procedure to be used: open cholecystectomy (OC), CO2 pneumoperitoneum cholecystectomy (PP), and laparoscopic gasless cholecystectomy (abdominal wall lifting [AWL]), respectively. A pulmonary artery catheter was used for hemodynamic monitoring in all patients. A subcutaneous multiplanar device (Laparo Tenser) was used for abdominal wall lifting. To avoid misinterpretation of results, conventional anesthesia was performed with all parameters, and the position of the patients held fixed throughout surgery. The following parameters were analyzed: mean arterial pressure (MAP), heart rate (HR), cardiac output (CO), cardiac index (CI), stroke volume index (SVI), central venous pressure (CVP), systemic vascular resistances index (SVRI), mean pulmonary arterial pressure (MPAP), pulmonary capillary wedge pressure (PCWP), pulmonary vascular resistances index (PVRI), peak inspiratory pressure (PIP), end-tidal CO2 pressure (ETCO)2, CO2 arterial pressure (PaCO2), and arterial pH.

RESULTS

All the operations were completed successfully. The Laparo Tenser allowed good exposition of the surgical field. A slight impairment of the cardiopulmonary functions, with reduction of SVRI, MAP, and CI and elevation of pulmonary pressures and vascular resistance, followed induction of anesthesia. However, these effects tended to normalize in the OC and AWL groups over time. In contrast, CO2 insufflation produced a complex hemodynamic and pulmonary syndrome resulting in increased right- and left side filling pressures, significant cardiac index reduction, derangement of the respiratory mechanics, and respiratory acidosis. All of these effects normalized after desufflation.

CONCLUSIONS

Cardiopulmonary adverse effects of general anesthesia were significant but transitory and normalized during surgery. Carbon dioxide pneumoperitoneum caused a significant impairment in cardiopulmonary functions. In high-risk patients, gasless laparoscopy may be preferred for reliability and absence of cardiopulmonary alterations.

Newly designed retraction devices for intestine control during laparoscopic aortic surgery: a comparative study in an animal model

BACKGROUND

Recent clinical studies have demonstrated the feasibility of laparoscopic surgery for aortic occlusive and aneurysmal disease. However, transperitoneal aortic access is compromised by poor exposure in the operative field from uncontrolled bowel. The retractors that are currently available are inadequate for this task. The development of new retractors would help to facilitate laparoscopic aortic surgery.

METHODS

Six female piglets (28-30 kg) in each group underwent laparoscopy with pneumoperitoneum (12 mmHg). Exposure of the infrarenal aorta and cross-clamping were undertaken through a transperitoneal approach. Two paddles inserted in a polyester bilayer (mobile device, group A) or a mesh net fixed to the abdominal wall (fixed device, group B) were used to retain the bowel. Aortotomy and suturing were performed to mimic a vascular procedure. After bleeding was controlled, the intraabdominal pressure (IAP) was lowered to 6 mmHg, and retraction was assessed for 30 min. The main outcome measures were time to deploy the retractors, time to perform the vascular procedure, time to withdraw the devices, and total procedural time. Blood loss and frequency of retraction failure were also recorded.

RESULTS

Mean time to deploy the device was 22 +/- 12 min in group A and 36 +/- 34 min in group B (n.s.). Vascular surgery time averaged 60 +/- 24 min in group A and 68 +/- 16 min in group B (n.s.). The times to withdraw the nets were 3.6 +/- 1.2 min and 13.5 +/- 8.2 min, respectively (p < 0.05). Total surgery time was 155 +/- 41 min vs 174 +/- 49 min (n.s.). There were six retraction failures, five in group A and one in group B. When lower IAP was used, there was only one failure in each study group. Mean blood loss was <150 ml in both groups. There were no major complications.

CONCLUSIONS

Both methods provided adequate exposure of the infrarenal aorta. Vascular surgery time and blood loss were similar for both groups. The movable device proved more usable and, at lower IAP, more effective. The results of this study demonstrate effective bowel retraction for laparoscopic aortic surgery.