Elective lower abdominal surgery is frequently performed under general anesthesia among gynecological cancer patient population. Gynecology tumor patients are mostly middle-aged and old, and they often have internal diseases such as hypertension, cardiovascular and cerebrovascular disease and other medical problems. Anesthetization is highly demanding in these operations due to the long time, wide expansion and large wound. Thus, it is important to choose the appropriate airway management.

Developments in anesthesia practice and airway management have increased safety of pediatric anesthesia (1,2). We improved airway management efficiency by using endotracheal intubation (ETI) or laryngeal mask airway (LMA) (3). There has been progress in the development of the design in the past ten years, changes in production material, and availability of various types. Anesthetists widely use ETI because of the advantages of good seal at the cricoid rings, decreased pressure, and thus a lower risk for mucosal injury (4). However, subglottic stenosis caused by a lack of cuff related mucosal perfusion due to cuff tube use, making their use controversial. In contrast, LMA has the advantages of a lack of direct contact with the trachea, no requirement for direct laryngoscopy, and a lower incidence of coughing (5–7).

We compared hemodynamics and respiratory function between LMA and ETI in gynecological cancer patients undergoing elective lower abdominal surgery (8,9).

A total of 54 patients were randomized in this study: 27 in the LMA group and 27 in the ETI group. The sex and age of the two groups were similar. The demographic and surgical data are presented in Table I.

Acceleration index (ACI), cardiac index (CI), cardiac output (CO), left cardiac work (LCW), systemic circulation resistance (SVR), mean arterial pressure (MAP), heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were recorded at 12 time-points: before surgery (T0), start effect (T1), lost consciousness (T2), before ETI or LMA (T3), 1 min (T4), 3 min (T5), 5 min (T6) after ETI or LMA, the beginning of surgery (T7), 30 min (T8), 2 hours (T9) after surgery, the end of surgery (T10) and extubation (T11) (Table II).

We found that in each group these indexes declined and then increased gently during surgery except for T4 and T12 especially in the ETI group. These indexes reached the highest at T11 (extubation). This is due to the stimulus on mucosa and muscle of root of tongue, throat and epiglottis from the windpipe. The stimulus excites sympathetic nerve and increases the release of catecholamine. As a result, the heart beats faster and blood pressure rises. However, the range in the LMA group is smaller especially at T4 and T11. This is most likely due to LMA not stimulating the trachea. ACI, CI, CO and LCW were higher in LMA with statistical significance at certain time-points (P<0.05) (Fig. 2A-D). Indexes such as SVR, MAP, HR, SBP and DBP were significantly higher in ETI (Fig. 2E-I).

LMA was developed by A. Brain in 1981, and since then, it has flourished in practice and has been used to treat millions of patients worldwide (10,11). The LMA provides more hands-free anesthesia than a facemask does, avoids many morbidities associated with tracheal intubation because there is no stress from the laryngoscope, and allows a faster recovery that does not require muscle relaxation (12,13). The LMA has become an important choice for routine use, particularly in outpatient surgeries (14–16).

In our investigation, we assessed the eligibility of LMA by comparing hemodynamics and respiratory function between LMA and ETI in gynecological cancer operation. The results showed that LMA can be used safely and induces less stress reaction in gynecological cancer patients undergoing lower abdominal surgery. The correlated clinical indexes recorded in 12 time-points declined and then increased gently during surgery except for the time-point of intubation (T4) and extubation (T11) especially in the ETI group. These indexes reached the highest at extubation (T11). This is due to the stimulus on mucosa and muscle of root of tongue, throat and epiglottis, from the windpipe. The stimulus excites sympathetic nerve and increases the release of catecholamine (17–21). As a result, hearts beat faster and blood pressure rises. However, the range in the LMA group is smaller especially at T4 and T11. This is possibly due to LMA not stimulating the trachea (22–25). One weakness of our design is that we could not get meaningful results using a multivariate logistic regression analysis. This may have been caused by the small number of samples. We will use a multivariate logistic regression analysis in future studies when a larger number of samples is available.

There were higher incidences of bucking in the ETI group in similar anesthesia in extubation. In addition, there were more postoperative complications in the ETI group such as pharyngalgia compared with LMA. This may be relevant to improper operation or excessive inflation of the catheter sleeve. This indicates that the stimulation of ETI is stronger than LMA. Most patients with ETI experience varying degrees of pharyngeal pain and have significant change in HR. However, patients with LMA do not have this complication. This is because LMA does not need to use laryngoscope and there is no need to enter trachea, thus avoid damaging tracheal mucosa and influencing circulation system. LMA has become complementary technology of ETI to offer a safe, effective, and simple ventilation method especially to the patient with microstomia. LMA is simpler to operate than ETI for medical workers and gains more time during emergency treatment. In addition, LMA is specifically suitable for the patient with microstomia (26).

In conclusion, the LMA may be a suitable method for airway management of patients with gynecological cancer under-going lower abdominal surgery (27,28). Furthermore, LMA is a good alternative to ETI with easier insertion, and lower incidence of cardiovascular response.