Define laparoscopy.

Laparoscopy is defined as a minimally invasive procedure where a laparoscope is used to enter the peritoneum. Once the peritoneal cavity is entered, insufflating gas creates a pneumoperitoneum. Laparoscopy may be used to examine abdominal or pelvic (pelviscopy) organs, diagnose conditions, and/or perform surgery [1].

Name some surgical procedures currently performed laparoscopically.

Laparoscopic procedures can be performed on all abdominal organs and includes gastrectomy, anti-reflux and bariatric procedures, cholecystectomy, hepatic and pancreatic resections, bowel and rectal surgery, adrenalectomy, and splenectomy [2]. Urological procedures performed laparoscopically include prostatectomy and nephrectomy. Laparoscopic gynecological surgeries include hysterectomy, ovarian, and tubal procedures [3].

What are the advantages of laparoscopic surgery? Which specific patient populations benefit most from laparoscopic procedures?

Advantages of laparoscopic surgery are several-fold. Recovery time is shortened. This is mostly due to minimal bowel manipulation during laparoscopy, reducing the incidence of postoperative ileus. Because of the smaller incisions associated with laparoscopic procedures, resultant scars are more cosmetic and there is less postoperative pain [4]. Decreased intraoperative blood loss and less frequent surgical wound infections are also seen [5]. For particular patient populations, i.e., morbidly obese patients and patients with significant cardiopulmonary comorbidities, the benefits of a minimally invasive procedure are truly apparent with respect to less postoperative pulmonary complications.

What are the disadvantages of laparoscopic surgery?

In addition to the steep learning curve for surgeons learning laparoscopic techniques, other disadvantages of laparoscopic surgery include poor depth perception and loss of dexterity due to limited range of motion using laparoscopic instruments [6].

What are some absolute and relative contraindications to laparoscopic surgery?

Most contraindications to laparoscopic surgery are relative and these risks must be compared to the benefits of a less invasive procedure. Relative contraindications include patients with pre-existing increased intracranial pressure (and/or space occupying lesion), severe hypovolemia and known right-to-left intracardiac shunts, for example, a patent foramen ovale [7].

What are optimal surgical conditions for laparoscopic surgery?

Optimal surgical conditions include gastrointestinal decompression via a bowel prep and or naso/orogastric tube placement. This permits easier and safer formation of the pneumoperitoneum for surgical exposure decreasing the chance of injury to organs when the instruments are inserted. Neuromuscular blockade relaxes abdominal wall muscles facilitating formation of the pneumoperitoneum [1, 8].

What is the gas of choice used to create the pneumoperitoneum during laparoscopy and why?

The gas of choice used to create the pneumoperitoneum is carbon dioxide (CO₂). This is due to its easy accessibility, low cost, and fairly inert and non-combustible properties. Carbon dioxide (CO₂) is highly soluble and rapidly buffered in blood and eliminated by the lungs [9].

What are the disadvantages to using carbon dioxide (CO₂)?

A disadvantage to using CO₂ as an exogenous gas for insufflation is that it is irritating to the peritoneum. Use of carbon dioxide may also lead to hypercarbia and respiratory acidosis and also cause metabolic, hormonal, and immunological adverse effects [10]. Although the incidence is low due to the high solubility of CO₂ in blood, the formation of a gas (CO₂) embolism could be catastrophic.

What concerns do you have about this patient’s history and physical with regards to laparoscopic surgery?

Her baseline pulmonary history (COPD) and obstructive sleep apnea (OSA) can predispose her to postoperative pulmonary complications. Morbid obesity may make the procedure more technically challenging for the surgeon to perform, and other obstacles, such as difficult airway, difficulty with ventilation in head-down position and positioning injuries may materialize. This patient is also anemic, which is likely due to her presenting symptom of menorrhagia, and may lead to a lower threshold for blood transfusion.

How does this patient’s medical history predispose her to postoperative pulmonary complications? What are the GOLD criteria? How are they best used?

This patient has Stage II COPD. The GOLD criteria are used to classify patients with COPD based on the severity of their degree of obstruction (Table 1). The degree of obstruction is determined by pulmonary function tests, specifically FEV₁ and FEV₁/FVC [11]:

What are the three main causes of the physiological changes seen with laparoscopic surgery?

Whether separate or in combination, the occurrence of the following are the main causes of the physiological changes seen during laparoscopic surgery:

What effect does laparoscopy have on the arterial to end-tidal CO₂ gradient (P_aCO₂-P_ETCO₂)?

In ASA I & II patients, the reliability of P_ETCO₂ for monitoring P_aCO₂ is generally not affected by the use of CO₂ as an insufflation gas during laparoscopy. This may not be the case for ASA III & IV patients, however. For these patients, the increase in alveolar dead space and/or increased ventilation/perfusion mismatch that occurs with laparoscopic insufflation may increase the normal alveolar–arterial (A-a) gradient (normally 3–5 mmHg) where even with a normal P_ETCO₂, the P_aCO₂ may be significantly elevated [15].

Does this patient need an arterial line? Why or why not?

Based on this patient’s history of Stage II COPD and OSA and the fact that P_ETCO₂ may not accurately reflect P_aCO₂, an arterial line may be beneficial. This will allow direct monitoring of P_aCO₂ which will aid in the management of the hypercarbia which occurs with laparoscopy.

What are the typical causes of hypercarbia seen during laparoscopic surgery?

The hypercarbia observed during laparoscopy could be a result of diffusion of CO₂ from the peritoneal cavity; hypoventilation; increase in the production of CO₂ (i.e., lactate and ketoacids); increased dead space (i.e., pulmonary embolism, severe COPD) [16].