Generation of a pneumoperitoneum induces significant physiological changes which must be appreciated, and compensated for, to avoid adverse outcomes. Specific groups may benefit from laparoscopic techniques such as obese patients or individuals with severe respiratory disease. Complications may have an insidious onset and all organizations undertaking laparoscopic surgery should have locally devised protocols to ensure staff recognize and rapidly act upon deteriorating patients after operation.
Laparoscopic techniques offer major benefits to the patient such as minimized incision size and trauma with reduced postoperative discomfort, shortened recovery rates, and a lower incidence of postoperative wound infections.
These factors all contribute to shorter in-patient stay and reduced perioperative morbidity. Consequently, many major procedures that once required prolonged postoperative recovery such as anterior resection of the rectum or radical cystectomy are now increasingly performed using laparoscopic techniques to improve patient outcomes. However, laparoscopic surgery is not without its own specific risks, either due to the risks associated with individual laparoscopic techniques or due to the physiological changes associated with the creation of a pneumoperitoneum.
As a result, anaesthetic techniques for laparoscopic surgery must be refined to anticipate these differences from open surgery. A major benefit of laparoscopic surgery is the shortened recovery time after major surgery Table 1. Reasons for this are multi-factorial: the laparoscopic approach reduces manipulation of the bowel and peritoneum, resulting in decreased incidence of postoperative ileus.
Therefore, enteral intake can be resumed more rapidly than with open surgical techniques, limiting requirements for i. Secondly, because small access points are required for the insertion of laparoscopic trocars, large incisions such as those seen in open procedures are avoided, thereby minimizing complications associated with postoperative pain and wound healing. As laparoscopic techniques have evolved, the number of port sites required has been reduced, with single-port surgery now a viable option.
These factors contribute to the reduced incidence of both wound and systemic infections demonstrated after laparoscopic surgery. These benefits are particularly useful in several patient groups.
Laparoscopic surgery is useful in obese patients in whom open procedures would be technically very challenging and who are particularly susceptible to wound infections after operation. An example of this is in bariatric surgery where laparoscopic gastric banding has improved short-term mortality rates compared with traditional open techniques. Other groups of patients who benefit from a laparoscopic approach include those with severe respiratory disease as the postoperative deterioration in respiratory function that may occur after large incisions with suboptimal analgesia is avoided.
The risks associated with laparoscopic surgery may be categorized as patient-specific, surgical, positional, or those associated with altered physiology secondary to the generation of pneumoperitoneum.
A recent National Patient Safety Agency NPSA report identified 48 serious incidents after laparoscopic surgery over a 7 yr period, including 11 deaths, and concluded that all organizations undertaking laparoscopic surgery should have local protocols to ensure that staff recognize and rapidly act upon deteriorating patients after operation. Laparoscopic surgery has traditionally been contraindicated in patients with severe ischaemic heart disease, valvular disease, significant renal dysfunction, or end-stage respiratory disease.
However, the risk to the individual patient must be balanced between the risk of complications due to the position, duration, degree of carbon dioxide CO 2 absorption, and physiological effects of pneumoperitoneum for a particular laparoscopic procedure vs the shortened postoperative recovery time which may outweigh the increased intraoperative risk. Generally accepted contraindications include pre-existing raised intracranial pressure, severe uncorrected hypovolaemia, and patients with known right-to-left cardiac shunts or patent foramen ovale.
The insertion of large trocars into the abdominal cavity, frequently without direct vision, carries the potential for damage to solid viscera, bowel, bladder, or blood vessels.
Although vascular injury within the pneumoperitoneum is usually apparent immediately, venous tamponade may occur with pneumoperitoneum, masking apparent bleeding. Furthermore, retroperitoneal haematomas are often insidious in nature and diagnosis may be delayed until the postoperative period, allowing significant haemorrhage to occur.
Venous gas embolism can result in catastrophic circulatory collapse and may be caused by direct trocar insertion into a vessel, or inadvertent inflation of a solid organ, and usually occurs as gas insufflation commences. The severity depends on the volume of CO 2 injected, rate of injection, patient position, and type of laparoscopic procedure. Fortunately, compared with venous air embolism, the risks are somewhat lower due to the increased solubility and rapid absorption of CO 2.
Patient positioning is determined by the view that the surgeon is trying to optimize, but often involves the extremes of the Trendelenburg or reverse Trendelenburg position with significant physiological effects. Extreme positions place the patient at risk of movement on the table, so meticulous attention must be paid to ensure that the patient is securely positioned with vulnerable pressure points and eyes being protected throughout the procedure.
Prolonged steep Trendelenburg position increases the risk of cerebral oedema, in addition to the risk associated with the pneumoperitoneum see below , and upper airway oedema which may present with stridor after operation.
The resultant compartment syndrome of the lower limbs presents after operation with disproportionate lower limb pain, rhabdomyolysis, and potentially myoglobin-associated acute renal failure leading to significantly increased morbidity and mortality. For prolonged surgery, at the authors' institution, the patient is returned to the horizontal position at least every 2 h and the lower limbs are massaged for 5—10 min before returning to the Trendelenburg position.
A pulse oximeter is also placed on the great toe throughout surgery to assess the adequacy of pulsatile flow to distal areas of the lower limbs. Particularly vulnerable are the elderly, hypovolaemic patients, and those with pre-existing ischaemic heart disease or cerebrovascular disease.
Intra-abdominal laparoscopic surgery requires the intentional generation of a pneumoperitoneum using insufflated carbon dioxide to enable sufficient visualization for the procedure to be performed. As the volume of the abdomen increases, abdominal wall compliance decreases and intra-abdominal pressure IAP climbs.
When the IAP exceeds physiological thresholds, individual organ systems become compromised, potentially increasing patient morbidity and mortality, particularly in those patients with relevant co-morbidities. However, several pathophysiological changes occur after carbon dioxide pneumoperitoneum and extremes of patient positioning. A thorough understanding of these pathophysiological changes is fundamental for optimal anesthetic care. Because expertise and equipment have improved, laparoscopy has become one of the most common surgical procedures performed on an outpatient basis and to sicker patients, rendering anesthesia for laparoscopy technically difficult and challenging.
Careful choice of the anesthetic technique must be tailored to the type of surgery. In the light of the haemodynamic consequences preservation of pulmonary function after laparoscopy, of laparoscopy, patients most at risk are those with the restrictive syndrome reported in these patients compromised ventricular function such as congestive is more marked than in healthy patients; it must there- heart failure , and those with severe valvular diseases fore be considered when caring for these patients.
The Preoperative optimization of respiratory function remains haemodynamic consequences of pneumoperitoneum are necessary even before minimally invasive surgery. In these patients, pneumoperitoneum alters the distri- It is well established that peri-operative risk in cardiac bution of pulmonary ventilation and perfusion.
This patients undergoing non-cardiac surgery is higher during results in an enlargement of alveolar dead space. This notion may be extended to laparoscopic decreased thoracopulmonary compliance secondary to surgery. Laparoscopy probably results in more pneumoperitoneum, airway pressures increase. To avoid haemodynamic changes than laparotomy. However, excessive airway pressures, which could potentially lead these changes occur mainly at the beginning of insuffla- to rupture of emphysematous bullae, the hyperventila- tion.
Moreover, knowledge and understanding of the tion normally required during CO2-pneumoperitoneum intraoperative changes, as well as the pathophysiology can be limited. As a consequence, permissive hyper- of the cardiac disease, allow them to be minimized. On capnia develops. A reduction in airway pressures can the other hand, the postoperative benefits of laparo- be also achieved by increasing respiratory rate rather scopy are welcome in these ill patients.
Anaesthetic than tidal volume. Finally, we also administer clonidine to management of cardiac patients comprises several these patients because it reduces metabolism and measures: attenuates the requirement for hyperventilation.
Caution is required in case of CO2-subcutaneous emphysema, 1 patients with a profile suggesting depleted intravas- since it increases the body load of CO2 to be eliminated cular volume experience the most severe haemo- and consequently the work of breathing. Preload augmentation before peritoneal insufflation partially offsets haemodynamic deterioration; Postoperative analgesia 2 insufflation must be slow, and intra-abdominal pres- sure must be kept as low as possible; Postoperative pain and analgesic requirements are less 3 vasodilators can be used to correct or prevent the after laparoscopy than laparotomy.
Tramadol clonidine 0. However, high individual variability in pain intensity is reported, and opioids still may be It should be kept in mind that pressures measured necessary in some patients.
Finally, controversy remains with a pulmonary artery catheter do not accurately regarding the efficacy of intraperitoneal instillation of reflect cardiac filling pressures during pneumoperi- local anaesthetics. Anaesthesia for the patient with chronic obstructive pulmonary disease3 Prevention of postoperative nausea The reduction in the postoperative pulmonary and vomiting restrictive syndrome observed after laparoscopy as compared to laparotomy justifies efforts to use the The incidence of nausea and vomiting is high after laparoscopic approach in patients with respiratory laparoscopy, particularly gynaecologic procedures.
Acute ventilatory compli- reduce the incidence of these side-effects: these cations during laparoscopic upper abdominal surgery. Can J Anaesth ; 77d Pneumothorax during laparoscopic administration of antiemetic medications, suction of fundoplication: diagnosis and treatment with positive end- gastric contents at the end of laparoscopy and expiratory pressure.
Anesth Analg ; d Struthers A D, Cuschieri A. Lancet ; d J Am Coll Cardiol. A better knowledge of the pathophysiologic changes Acta Anaesthesiol Scand ; d Increased surgeon experience is associated R C et al. Pharmacologic intervention can reestablish baseline with decreased operative times and rates of minor or hemodynamic parameters during laparoscopy. Surgery ; moderate surgical complications. At this time, the pos- d Hemodynamic changes during laparoscopic cholecystectomy in patients with severe effects, which can be corrected or prevented by an cardiac disease.
J Clin Anesth ; 9: d Hemodynamic pneumoperitoneum. This balance in favour of laparos- effects of increased intraabdominal pressure. J Surg Res ; copy justifies efforts to apply the laparoscopic approach d Thromboembolism in laparoscopic surgery: risk factors and preventive measures. Surg Laparosc Endosc ; 9: d Serial changes in renal function during laparoscopic 1. Metabolic and respiratory cholecystectomy.
Eur Surg Res ; d Br J Anaesth ; d Esselborn S. Effects of intraabdominally insufflated carbon dioxide 2. Kehlet H. Surgical stress response: does endoscopic surgery confer and elevated intraabdominal pressure on splanchnic circulation: an an advantage?
World J Surg ; d Anesthesiology ; d Joris J. Anesthesia for laparoscopic surgery. In: R. Miller ed New York: Churchill Livingstone, Lindgren L. A comparison of gasless mechanical and conventional 4. Cardiopulmonary function and carbon dioxide pneumoperitoneum methods for laparoscopic laparoscopic cholecystectomy. Can J Anaesth ; 51d The
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