title: Effects of laparoscopic cholecystectomy on lung function: a systematic review.
abstract: OBJECTIVE
  To present and integrate findings of studies investigating the effects of laparoscopic cholecystectomy on various aspects of lung function.
  
  
  METHODS
  We extensively reviewed literature of the past 24 years concerning the effects of laparoscopic cholecystectomy in comparison to the open procedure on many aspects of lung function including spirometric values, arterial blood gases, respiratory muscle performance and aspects of breathing control, by critically analyzing physiopathologic interpretations and clinically important conclusions. A total of thirty-four articles were used to extract information for the meta-analysis concerning the impact of the laparoscopic procedure on lung function and respiratory physiopathology. The quality of the literature reviewed was evaluated by the number of their citations and the total impact factor of the corresponding journals. A fixed and random effect meta-analysis was used to estimate the pooled standardized mean difference of studied parameters for laparoscopic (LC) and open (OC) procedures. A crude comparison of the two methods using all available information was performed testing the postoperative values expressed as percentages of the preoperative ones using the Mann-Whitney two-sample test.
  
  
  RESULTS
  Most of the relevant studies have investigated and compared changes in spirometric parameters.The median percentage and interquartile range (IQR) of preoperative values in forced vital capacity (FVC), forced expiratory volume in 1 s and forced expiratory flow (FEF) at 25%-75% of FVC (FEF25%-75%) expressed as percentage of their preoperative values 24 h after LC and OC were respectively as follows: [77.6 (73.0, 80.0) L vs 55.4 (50.0, 64.0) L, P < 0.001; 76.0 (72.3, 81.0) L vs 52.5 (50.0, 56.7) L, P < 0.001; and 78.8 (68.8, 80.9) L/s vs 60.0 (36.1, 66.1) L/s, P = 0.005]. Concerning arterial blood gases, partial pressure of oxygen [PaO2 (kPa)] at 24 or 48 h after surgical treatment showed reductions that were significantly greater in OC compared with LC [LC median 1.0, IQR (0.6, 1.3); OC median 2.4, IQR (1.2, 2.6), P = 0.019]. Fewer studies have investigated the effect of LC on respiratory muscle performance showing less impact of this surgical method on maximal respiratory pressures (P < 0.01); and changes in the control of breathing after LC evidenced by increase in mean inspiratory impedance (P < 0.001) and minimal reduction of duty cycle (P = 0.01) compared with preoperative data.
  
  
  CONCLUSIONS
  Laparoscopic cholecystectomy seems to be associated with less postoperative derangement of lung function compared to the open procedure.
authors.affiliation: George D Bablekos, Konstantinos A Charalabopoulos, Department of Experimental Physiology, Medical School, Democritous University of Thrace, 68100 Alexandroupolis, Greece.
authors.forename: George D
authors.initials: GD
authors.lastname: Bablekos
authors.affiliation: George D Bablekos, Konstantinos A Charalabopoulos, Department of Experimental Physiology, Medical School, Democritous University of Thrace, 68100 Alexandroupolis, Greece.
authors.forename: Stylianos A
authors.initials: SA
authors.lastname: Michaelides
authors.affiliation: George D Bablekos, Konstantinos A Charalabopoulos, Department of Experimental Physiology, Medical School, Democritous University of Thrace, 68100 Alexandroupolis, Greece.
authors.forename: Antonis
authors.initials: A
authors.lastname: Analitis
authors.affiliation: George D Bablekos, Konstantinos A Charalabopoulos, Department of Experimental Physiology, Medical School, Democritous University of Thrace, 68100 Alexandroupolis, Greece.
authors.forename: Konstantinos A
authors.initials: KA
authors.lastname: Charalabopoulos
mesh_terms: D017081:Cholecystectomy, Laparoscopic / Q000009:adverse effects*; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008171:Lung Diseases / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D008450:Maximal Midexpiratory Flow Rate; D018570:Risk Assessment; D012307:Risk Factors; D016896:Treatment Outcome; D014797:Vital Capacity
keywords: Cholecystectomy; Laparoscopic; Open procedure; Respiratory function; Respiratory physiology