Benefits of pulmonary artery catheter and transesophageal echocardiographic monitoring in laparoscopic cholecystectomy patients with cardiac disease

Goal-Directed Fluid Therapy Enhances Gastrointestinal Recovery after Laparoscopic Surgery: A Systematic Review and Meta-Analysis

(1) Background: Whether goal-directed fluid therapy (GDFT) provides any outcome benefit as compared to non-goal-directed fluid therapy (N-GDFT) in elective abdominal laparoscopic surgery has not been determined yet. (2) Methods: A systematic literature search was conducted in MEDLINE, Embase, CENTRAL, Web of Science, and Scopus. The main outcomes were length of hospital stay (LOHS), time to first flatus and stool, intraoperative fluid and vasopressor requirements, serum lactate levels, and urinary output. Pooled risks ratios (RRs) with 95% confidence intervals (CI) were calculated for dichotomous outcomes and weighted mean difference (WMD) with 95% CI for continuous outcomes. (3) Results: Eleven studies were included in the quantitative, and fifteen in the qualitative synthesis. LOHS (WMD: −1.18 days, 95% CI: −1.84 to −0.53) and time to first stool (WMD: −9.8 h; CI −12.7 to −7.0) were significantly shorter in the GDFT group. GDFT resulted in significantly less intraoperative fluid administration (WMD: −441 mL, 95% CI: −790 to −92) and lower lactate levels at the end of the operation: WMD: −0.25 mmol L−1; 95% CI: −0.36 to −0.14. (4) Conclusions: GDFT resulted in enhanced recovery of the gastrointestinal function and shorter LOHS as compared to N-GDFT.

Cardiovascular and Ventilatory Consequences of Laparoscopic Surgery

Although laparoscopic surgery accounts for >2 million surgical procedures every year, the current preoperative risk scores and guidelines do not adequately assess the risks of laparoscopy. In general, laparoscopic procedures have a lower risk of morbidity and mortality compared with operations requiring a midline laparotomy. During laparoscopic surgery, carbon dioxide insufflation may produce significant hemodynamic and ventilatory consequences such as increased intraabdominal pressure and hypercarbia. Hemodynamic insults secondary to increased intraabdominal pressure include increased afterload and preload and decreased cardiac output, whereas ventilatory consequences include increased airway pressures, hypercarbia, and decreased pulmonary compliance. Hemodynamic effects are accentuated in patients with cardiovascular disease such as congestive heart failure, ischemic heart disease, valvular heart disease, pulmonary hypertension, and congenital heart disease. Prevention of cardiovascular complications may be accomplished through a sound understanding of the hemodynamic and physiological consequences of laparoscopic surgery as well as a defined operative plan generated by a multidisciplinary team involving the preoperative consultant, anesthesiologist, and surgeon.

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.

The role of intraoperative transesophageal echocardiographic monitoring in a patient with hypertrophic cardiomyopathy undergoing laparoscopic surgery

Hypertrophic cardiomyopathy (HCM) presents a significant perioperative challenge. Anesthetic drugs, patient positioning, and surgical technique can provoke worsening left ventricular outflow tract obstruction and hemodynamic deterioration. In this case report, we present the perioperative management of a 70-year-old male with a history of HCM who underwent a robotic laparoscopic prostatectomy. Discussion focuses on the utilization of echocardiographic guidance in the care of patients with HCM undergoing noncardiac surgery, as well as the pathophysiology of laparoscopic insufflation and its effects on left ventricular outflow tract obstruction in HCM.

Laparoscopic approach to acute abdomen from the Consensus Development Conference of the Società Italiana di Chirurgia Endoscopica e nuove tecnologie (SICE), Associazione Chirurghi Ospedalieri Italiani (ACOI), Società Italiana di Chirurgia (SIC), Società Italiana di Chirurgia d'Urgenza e del Trauma (SICUT), Società Italiana di Chirurgia nell'Ospedalità Privata (SICOP), and the European Association for Endoscopic Surgery (EAES)

BACKGROUND

In January 2010, the SICE (Italian Society of Endoscopic Surgery), under the auspices of the EAES, decided to revisit the clinical recommendations for the role of laparoscopy in abdominal emergencies in adults, with the primary intent being to update the 2006 EAES indications and supplement the existing guidelines on specific diseases.

METHODS

Other Italian surgical societies were invited into the Consensus to form a panel of 12 expert surgeons. In order to get a multidisciplinary panel, other stakeholders involved in abdominal emergencies were invited along with a patient's association. In November 2010, the panel met in Rome to discuss each chapter according to the Delphi method, producing key statements with a grade of recommendations followed by commentary to explain the rationale and the level of evidence behind the statements. Thereafter, the statements were presented to the Annual Congress of the EAES in June 2011.

RESULTS

A thorough literature review was necessary to assess whether the recommendations issued in 2006 are still current. In many cases new studies allowed us to better clarify some issues (such as for diverticulitis, small bowel obstruction, pancreatitis, hernias, trauma), to confirm the key role of laparoscopy (such as for cholecystitis, gynecological disorders, nonspecific abdominal pain, appendicitis), but occasionally previous strong recommendations have to be challenged after review of recent research (such as for perforated peptic ulcer).

CONCLUSIONS

Every surgeon has to develop his or her own approach, taking into account the clinical situation, her/his proficiency (and the experience of the team) with the various techniques, and the specific organizational setting in which she/he is working. This guideline has been developed bearing in mind that every surgeon could use the data reported to support her/his judgment.

Hemodynamic perturbations during robot-assisted laparoscopic radical prostatectomy in 45° Trendelenburg position

BACKGROUND

Robot-assisted laparoscopic radical prostatectomy has gained widespread use. However, circulatory effects in patients subjected to an extreme Trendelenburg position (45°) are not well characterized.

METHODS

We studied 16 patients (ASA physical status I-II) with a mean age of 59 years scheduled for robot-assisted laparoscopic radical prostatectomy (45° head-down tilt, with an intraabdominal pressure of 11-12 mm Hg). Hemodynamics, echocardiography, gas exchange, and ventilation-perfusion distribution were investigated before and during pneumoperitoneum, in the Trendelenburg position and, in 8 of the patients, also after the conclusion of surgery.

RESULTS

In the 45° Trendelenburg position, central venous pressure increased almost 3-fold compared with the initial value, with an associated 2-fold increase in mean pulmonary artery pressure and pulmonary capillary wedge pressure (P<0.01). Mean arterial blood pressure increased by 35%. Heart rate, stroke volume, cardiac output, and mixed venous oxygen saturation were unaffected during surgery, as were echocardiographic heart dimensions. After induction of anesthesia, isovolumic relaxation time was prolonged, with no further change during the study. Deceleration time was normal and stable. In the horizontal position after pneumoperitoneum exsufflation, filling pressures and mean arterial blood pressure returned to baseline levels. Pneumoperitoneum reduced lung compliance by 40% (P<0.01). Addition of the Trendelenburg position caused a further decrease (P<0.05). Arterial blood acid-base balance was normal. End-tidal carbon dioxide tension increased whereas arterial carbon dioxide was unaffected with unchanged ventilation settings. Pneumoperitoneum increased PaO2 (P<0.05). Ventilation-perfusion distribution, shunt, and dead space were unaltered during the study.

CONCLUSIONS

Pneumoperitoneum and 45° Trendelenburg position caused 2- to 3-fold increases in filling pressures, without effects on cardiac performance. Filling pressures were normalized immediately after surgery. Lung compliance was halved. Gas exchange was unaffected. No perioperative cardiovascular complications occurred.

Clinical advantages of laparoscopic colorectal cancer surgery in the elderly

BACKGROUND AND AIMS

Elderly patients have a high incidence of colorectal cancer, which may be associated with increased morbidity and mortality due to complex comorbidity and diminished cardiopulmonary reserves. The aims of this study were to compare the outcomes of laparoscopic colorectal cancer surgery with those observed in traditional open surgery in patients aged over 70 years.

METHODS

Between January 2003 and October 2004, 51 patients aged over 70 years with colorectal cancer, who underwent laparoscopic surgery (LAP group), were evaluated and compared with 102 controls (also over 70 years old) treated by traditional open surgery (OPEN group) in the same period. All patients were evaluated with respect to the American Society of Anesthesiologists (ASA) classification, surgery-related complications, and postoperative recovery.

RESULTS

No surgery-related death was observed in the LAP group, whereas two deaths occurred in the OPEN group for severe post-operative pulmonary infection and anastomotic leak, respectively. No pneumoperitoneum-related complications were observed in the LAP group; 2 (3.9%) patients required conversion to open surgery, because of the unexpectedly bulky tumor and severe adhesions in the abdominal cavity. With the increase in patients' age, increased ASA classification was observed. No significant differences were observed in gender, Dukes' staging or types of procedures between LAP and OPEN groups. The overall morbidity in the LAP group was significantly less than that of the OPEN group [17.6% (9/51) vs 37.3% (38/102), p=0.013]. Mean blood loss, time to flatus passage, and time to semi-liquid diet in the LAP group were significantly shorter than those of the OPEN group (90.7+/-49.9 vs 150.3+/-108.7 ml, 2.4+/-1.2 vs 3.5+/-2.9 d, 5.0+/-1.8 vs 5.9+/-1.2 d, respectively, p<0.05). No significant differences were observed in terms of mean operation time or hospital stay between LAP and OPEN groups.

CONCLUSION

Laparoscopic colorectal cancer surgery in elderly patients with colon cancer has clinically significant advantages over traditional open surgery, and appears to be the ideal surgical choice for the elderly.

Pneumoperitoneum versus abdominal wall lift: effects on central haemodynamics and intrathoracic pressure during laparoscopic cholecystectomy

BACKGROUND

It has been shown repeatedly that laparoscopic cholecystectomy using pneumoperitoneum (CO2 insufflation) may be associated with increased cardiac filling pressures and an increase in blood pressure and systemic vascular resistance. In the present study, the effects on the central circulation during abdominal wall lift (a gasless method of laparoscopic cholecystectomy) were compared with those during pneumoperitoneum. The study was also aimed at elucidating the relationships between the central filling pressures and the intrathoracic pressure.

METHODS

Twenty patients (ASA I), scheduled for laparoscopic cholecystectomy, were randomised into two groups, pneumoperitoneum or abdominal wall lift. Measurements were made by arterial and pulmonary arterial catheterization before and during pneumoperitoneum or abdominal wall lift with the patient in the horizontal position. Measurements were repeated after head-up tilting the patients as well as after 30 min head-up tilt. The intrathoracic pressure was monitored in the horizontal position before and during intervention using an intraesophageal balloon.

RESULTS

After pneumoperitoneum or abdominal wall lifting there were significant differences between the two groups regarding MAP, SVR, CVP, CI, and SV. Analogous to previous studies, in the pneumoperitoneum group CVP, PCWP, MPAP, and MAP as well as SVR were increased after CO2 insufflation (P < 0.01), while CI and SV were not affected. In contrast, in the abdominal wall lift group, CI and SV were significantly increased (P < 0.01), as was MAP (P < 0.01), while CVP, PCWP, MPAP, and SVR were not significantly affected. There was a significant difference in intraesophageal pressure between the two groups. In the pneumoperitoneum group, the intraesophageal pressure was increased by insufflation (P < 0.01) while, in the abdominal wall lift group, it was unaffected. In the pneumoperitoneum group the mean increases in cardiac filling pressures were of the same magnitude as the mean increase in the intraesophageal pressure.

CONCLUSIONS

In healthy patients, abdominal wall lift increased cardiac index while pneumoperitoneum did not. Cardiac filling pressures and systemic vascular resistance were increased by pneumoperitoneum but unaffected by abdominal wall lift. The recorded elevated cardiac filling pressures during pneumoperitoneum may be only a reflection of the increased intra-abdominal pressure.

Effects of intra-abdominal CO2-insufflation on normal and impaired myocardial function: an experimental study

BACKGROUND

Intra-abdominal pressure (IAP) elevation during CO2-pneumoperitoneum increases cardiac afterload and may enhance dysfunction of the already compromised heart. This study focused on the effects of acute IAP increases on left and right ventricular loadings and contractility in the heart with impaired global function.

METHODS

Impairment of myocardial function (IMF) was pharmacologically induced in 16 pigs by administration of halothane and propranolol, while baseline arterial pressure was maintained by intravenous phenylephrine. Intra-abdominal pressure was gradually increased by 10 mmHg up to 30 mmHg in the supine position (IMF group 1, n = 8) or in a head-down tilted position (IMF group 2, n = 8). In two control groups with normal myocardial function, IAP was also increased in the supine position or the head-down tilted position. Cardiac function in all groups was assessed by epicardial echocardiography, intraventricular pressure measurements and pulmonary artery catheterization.

RESULTS

The increase in IAP was accompanied by a transient rise in LV end-systolic wall stress and reduced cardiac output significantly by 16-24% in all groups. In the IMF groups, LV end-diastolic transmural pressure increased by 34-60% to peak values of 24 mmHg, while cross-sectional LV end-diastolic areas remained unchanged. Increases in right ventricular end-diastolic volume and decreases in right ventricular ejection fraction as well as in cardiac output were most pronounced at IAP 20 mmHg and significantly stronger in both IMF groups than in the control groups (P < 0.001).

CONCLUSION

Following the acute elevation of IAP, the right ventricular volume load shifted more extensively in the IMF groups than in the animals with normal myocardial function. Myocardial function in the impaired heart may worsen during IAP elevation due to right ventricular load alterations rather than a LV afterload increase.

Transoesophageal acoustic quantification for evaluation of cardiac function during laparoscopic surgery

Pneumoperitoneum may be poorly tolerated in patients with marginal cardiopulmonary function. Transoesophageal echocardiography is a relatively non-invasive technique that can track changes in left ventricular cavity area using acoustic quantification and has been found to provide a reliable, real-time estimation of left ventricular function. We evaluated mid-papillary fractional area change during pneumoperitoneum in 17 healthy adult patients (group 1) and 17 with hypertension and/or ischaemic heart disease (group 2) undergoing laparoscopic cholecystectomy. Peritoneal insufflation led to significant (p < 0.01) decreases in fractional area change and an increase in mean blood pressure. There was no significant change in heart rate. Patients with cardiovascular disease who had a > 30% decrease in fractional area change following carbon dioxide insufflation (group 2B) were given an intravenous infusion of glyceryl trinitrate. In groups 1 and 2A, fractional area change improved slightly with head-up tilt and continued to improve over the course of surgery. Glyceryl trinitrate led to a significant increase in fractional area change and a decrease in mean blood pressure back to baseline values. We conclude that peritoneal insufflation of carbon dioxide results in a significant increase in cardiac workload that is well tolerated in patients with no cardiovascular disease. Coexisting cardiovascular disease can result in even more pronounced impairment of cardiac function, which may not be predictable by clinical assessment or adequately determined by routine monitoring. We recommend the use of transoesophageal acoustic quantification as a monitor in these patients and the administration of glyceryl trinitrate to ameliorate myocardial stress.

Influence of pneumoperitoneum and patient positioning on preload and splanchnic blood volume in laparoscopic surgery of the lower abdomen

STUDY OBJECTIVE

To determine the hemodynamic effects of pneumoperitoneum and patient positioning during laparoscopic surgery of the lower abdomen.

DESIGN

Prospective study.

SETTING

University-affiliated medical center.

PATIENTS

10 ASA physical I and II female patients scheduled for laparoscopic surgery of the lower abdomen.

INTERVENTIONS

Patients were anesthetized with propofol and an alfentanil infusion, then intubated, and normoventilated.

MEASUREMENTS

After intubation, a transesophageal multiplane probe for measurements of right (RVESA) and left (LVESA) ventricular end-systolic and end-diastolic areas (RVEDA and LVEDA) and ejection fraction area (RVEFa, LVEFa) was introduced; heart rate (HR) and noninvasive blood pressure (BP) were recorded every minute. Ventilation was not changed during the measurements. A transvaginal ultrasound probe was inserted to measure the diameter of the common iliac vein. Measurements were performed 15 minutes after induction of anesthesia and while patients were in the supine position (P 0), 10 minutes after CO(2) insufflation to 10 mmHg IA pressure (P 10), 10 minutes after a further increase to 15 mmHg (P 15), 10 minutes after 20 degrees Trendelenburg (P 15 T), and 20 degrees reverse Trendelenburg positions (P 15 RT). Data are shown as medians, 25th to 75th percentiles, and comparisons between P 0, P 10, P 15, and P15 T were made with the Friedman test, followed by Wilcoxon test, when significant. Data at P 15 T, P 15 RT, and P 15 were compared using the Wilcoxon test, with a p-value < 0.05 regarded as significant.

MAIN RESULTS

Pneumoperitoneum at 10 mmHg abdominal pressure caused a significant increase of LVESA by 78% (RVESA: 61%) and LVEDA by 48.5% (RVEDA: 45%). The diameter of the common iliac vein was decreased by 6%. A further increase of abdominal pressure to 15 mmHg led to an additional increase of 20% (LVESA) and 17% (LVEDA). Mean arterial pressure increased by a significant 7% at P 10, decreasing subsequently by 5% at P 15. The Trendelenburg position did not alter any hemodynamic findings. Reverse Trendelenburg position, however, caused a significant LVEDA-and RVEDA-decrease by 18% and 27%, respectively, and an increase in the diameter of the common iliac vein by 22%. The LVEFa and RVEFa decreased significantly after abdominal CO(2) insufflation by 18% each (P 10) without further change.

CONCLUSIONS

The lithotomy position and subsequent pneumoperitoneum increased preload, probably as a result of blood shifting from the abdomen to the thorax by compression of splanchnic vessels caused by the pneumoperitoneum. Careful fluid management, maintaining low abdominal pressure, and use of the reverse Trendelenburg position are favored to prevent adverse hemodynamic effects in laparoscopic surgery.

Laparoscopic surgery in older adults

This article provides an overview of the current role of laparoscopic surgery in older patients. A retrospective review and analysis of the recent English-language literature on laparoscopic procedures with special attention devoted to those articles focused on geriatric patients was performed. Laparoscopic surgery has rapidly become the fastest-growing discipline within the surgical arena and new applications for laparoscopy continue to be reported. The primary benefits to patients of these developments are smaller scars, decreased postoperative pain, and more-rapid return to normal activity. As society ages, more older patients will present with pathology amenable to laparoscopic intervention. Several aspects of laparoscopy impose unique physiologic stresses and, as such, may alter surgical risk to the geriatric patient. In addition, older patients often have delayed surgical interventions because of more-conservative medical management or unusual symptomatology, which may further complicate the laparoscopic approach. These limitations may alter the risk-to-benefit ratio of laparoscopic versus open procedures. Despite this lack of elucidation of full-risk profiles, laparoscopic approaches should be considered regardless of a patient's age.

Use of impedance cardiography to monitor haemodynamic changes during laparoscopy in children

METHODS

Haemodynamic changes were measured noninvasively using impedance cardiography (ICG) in 30 ASA I children during laparoscopic varicocelectomy under general anaesthesia. After induction and intubation, mechanical ventilation was started, then pneumoperitoneum (PP) was created. During the course of anaesthesia, values of endtidal CO2 pressue (PECO2), peak inspiratory airway pressure (PIP), heart rate (HR), mean arterial blood pressure (MABP), stroke volume index (SVI), cardiac index (CI) and systemic vascular resistance index (SVRI) were recorded at 1 min intervals. We analysed four periods: T1, before induction; T2, after induction; T3, during PP; T4, after desufflation of PP until awake.

RESULTS

After induction of anaesthesia a significant reduction of HR, MABP and CI was recorded. Creating PP together with the use of a 15 degrees head down tilt resulted in a further drop in CI, mainly caused by the reduction of SVI, and an elevation of MABP and SVRI. We measured a 25% total decrease of CI.

CONCLUSION

Our patients tolerated this significant reduction of cardiac output well. We have demonstrated that ICG can be used to track the haemodynamic changes caused by PP in children, and suggest that this type of monitoring is useful in this group of age during laparoscopy.

Advanced age--indication or contraindication for laparoscopic colorectal surgery?

PURPOSE

It has been proposed that laparoscopic colorectal surgery offers several benefits to patients. The aim of this study was to evaluate particularly whether older patients can benefit by laparoscopic colorectal procedures or if minimally invasive procedures are contraindicated.

METHODS

All patients who underwent elective surgery were divided into age-related groups: patients 50 years of age or younger, patients ranging from 51 to 70 years of age, and patients older than 70 years. The groups by age were compared with each other relative to their cardiopulmonary status, indication, procedure, conversion, morbidity, mortality, duration of surgery, perioperative blood transfusion, stay on the intensive care unit, and hospitalization. Statistical analysis included univariate analysis by chi-squared tests and Student's t-tests comparing patients older than 70 years with patients 50 years of age or younger and with patients ranging from 51 to 70 years of age (statistical significance was defined as P < 0.05).

RESULTS

Within five years 298 patients (male/female ratio, 0.38) underwent a laparoscopic or laparoscopic-assisted colorectal procedure. Of these, 95 (31.9 percent) patients were older than 70 years, 138 (46.3 percent) patients ranged from 51 to 70 years of age, and 65 (21.8 percent) patients were 50 years of age or younger. Pathologic findings in cardiopulmonary function increased with age. There were no statistically significant differences among the younger, middle-aged, and older patients relative to the incidence of conversion (3.1 vs. 9.4 vs. 7.4 percent, respectively), major complications (4.6 vs. 10.1 vs. 9.5 percent, respectively), minor complications (12.3 vs. 15.2 vs. 12.6 percent, respectively) or total laparotomy rate (7.7 vs. 12.3 vs. 12.6 percent, respectively). P > 0.05 for all comparisons. However, duration of surgery, stay on the intensive care unit, and postoperative hospitalization were significantly prolonged in patients older than 70 years (P < 0.05 for all comparisons) but were reduced during the five years of experience with these procedures.

CONCLUSIONS

If preoperative assessment of comorbid conditions and perioperative care was ensured, laparoscopic procedures were shown to be safe options in the elderly. The outcome of laparoscopic colorectal surgery in patients older than 70 years is similar to that noted in younger patients. Advanced age is no contraindication for laparoscopic colorectal surgery.

The role of intra-abdominal pressure on splanchnic and pulmonary hemodynamic and metabolic changes during carbon dioxide pneumoperitoneum

BACKGROUND AND METHODS

To find an intra-abdominal pressure (IAP) range for laparoscopic procedures that elicits only moderate splanchnic and pulmonary hemodynamic and metabolic changes, including hepatic and intestinal tissue pH and superficial hepatic blood flow, we installed an IAP of 7 and 14 mm Hg each for 30 minutes in 10 healthy pigs (30 +/- 4 kg).

RESULTS

In parallel with the increase of IAP, the mean transmural pulmonary artery pressure increased (from 25 +/- 3 to 27 +/- 4 at 7 mm Hg IAP and 30 +/- 6 mm Hg at 14 mm Hg IAP, p < 0.05); the pulmonary artery-to-pulmonary capillary wedge pressure gradient also increased (from 17 +/- 2.7 to 21 +/- 3 mm Hg at 7 mm Hg IAP and 24 +/- 4.2 mm Hg at 14 mm Hg IAP, p < 0.01), and the arterial oxygenation decreased (p < 0.005). Relevant changes at an IAP of 14 mm Hg were observed in right atrial pressure during inspiration (from 7 +/- 2 to 12 +/- 3 mm Hg, p < 0. 0001) and in abdominal aortic flow (from 1.43 +/- 0.4 to 1.19 +/- 0. 3 L/min, p < 0.01). However, transmural right atrial pressure and cardiac output remained essentially unchanged. Portal and hepatic venous pressure increased in parallel with the IAP (portal: from 12 +/- 3 to 17 +/- 3 at 7 mm Hg IAP and 22 +/- 3 mm Hg at 14 mm Hg IAP, p < 0.01; hepatic venous: from 8 +/- 3 to 14 +/- 6 at 7 mm Hg IAP and 19 +/- 6 mm Hg at 14 mm Hg IAP, p < 0.005), but the transmural portal and hepatic venous pressures decreased (p < 0.01), indicating decreased venous filling. Portal flow was maintained at 7 mm Hg but decreased at 14 mm Hg from 474 +/- 199 to 395 +/- 175 mL/min (p < 0. 01), whereas hepatic arterial flow remained stable. Hepatic superficial blood flow decreased during insufflation and increased after desufflation. Tissue pH fell together with portal and hepatic venous pH (intestinal: from 7.323 +/- 0.05 to 7.217 +/- 0.04; hepatic: from 7.259 +/- 0.04 to 7.125 +/- 0.06, both p < 0.01) at 14 mm Hg.

CONCLUSION

The hemodynamic and metabolic derangement in the pulmonary and splanchnic compartments are dependent on the extent of carbon dioxide pneumoperitoneum. The effect of low IAP (7 mm Hg) on splanchnic perfusion is minimal. However, higher IAPs (14 mm Hg) decrease portal and superficial hepatic blood flow and hepatic and intestinal tissue pH.

Laparoscopic surgery and its potential for medical complications

Laparoscopic surgery is very popular among physicians and patients because this technique is associated with safety, shorter hospital stay, early return to normal activity, and cosmetic acceptance of the operative scar. Although the procedure involves minimal invasion and tissue damage, it has potentially serious complications, including cardiopulmonary effects that result mainly from hypercarbia and raised intraabdominal pressure caused by pneumoperitoneum. Absorbed carbon dioxide from the peritoneal cavity tends to cause acidosis. Leakage of the gas into tissue spaces may induce subcutaneous emphysema, pneumothorax, pneumomediastinum and pneumopericardium. Cardiac effects include arrhythmias, hypotension, cardiac arrest, gas embolism, pulmonary edema, and myocardial ischemia or infarction. Some of these effects, though rare, are serious and potentially fatal. Physicians should anticipate these problems in their patients undergoing laparoscopic procedures. This review discusses the technique of and physiologic considerations in laparoscopic surgery as well as its potential complications.