Effect of obesity and site of surgery on perioperative lung volumes

• Published in: British journal of anaesthesia : BJA Vol. 92; no. 2; pp. 202 - 207
• Main Authors: von Ungern‐Sternberg, B. S., Regli, A., Schneider, M. C., Kunz, F., Reber, A.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-02-2004; Oxford University Press; Oxford Publishing Limited (England)
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; anaesthesia; Anesthesia; Anesthesia, General; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Body Mass Index; complications; complications, obesity; Female; Forced Expiratory Volume; Humans; Hysterectomy; lung; lung, respiratory function; Mastectomy; Medical sciences; Middle Aged; monitoring; monitoring, spirometry; obesity; Obesity - complications; Obesity - physiopathology; Pain, Postoperative; pharmacokinetics; pharmacokinetics, body mass index; Postoperative Complications; Postoperative Period; Prospective Studies; respiratory function; Respiratory Insufficiency - etiology; Spirometry; Vital Capacity; lung, respiratory function; pharmacokinetics, body mass index; complications, obesity; monitoring, spirometry; anaesthesia; anaesthesia; complications, obesity; lung, respiratory function; monitoring, spirometry; pharmacokinetics, body mass index; Human; Postoperative; Obesity; Spirometry; Head; Induction; Position; anaesthesia; complications; Lung; body mass index; Nutrition disorder; General anesthesia; Vital capacity; Respiratory system; obesity; lung; spirometry; pharmacokinetics; respiratory function; monitoring; Lung volume; Surgery; Complication; Mammary gland; Preoperative; Laparotomy; Premedication
• ISSN: 0007-0912; 1471-6771
• DOI: 10.1093/bja/aeh046

Background.Although obese patients are thought to be susceptible to postoperative pulmonary complications, there are only limited data on the relationship between obesity and lung volumes after surgery. We studied how surgery and obesity affect lung volumes measured by spirometry.
We prospectively studied 161 patients having either breast surgery (Group A, n=80) or lower abdominal laparotomy (Group B, n=81). Premedication and general anaesthesia were standardized. Spirometry was measured with the patient supine, in a 30° head-up position. We measured vital capacity (VC), forced vital capacity, peak expiratory flow and forced expiratory volume in 1 s at preoperative assessment (baseline), after premedication (before induction of anaesthesia) and 10–20 min, 1 h and 3 h after extubation.
Baseline spirometric values were all within the normal range. All perioperative values decreased significantly with increasing body mass index (BMI). The greatest reduction of mean VC (expressed as percentage of baseline values) occurred after extubation, and was more marked after laparotomy than after breast surgery (23 (sd 14)% vs 20 (14)%). Considering patients according to BMI (<25, 25–30, >30), VC decreased after surgery by 12 (7)%, 24 (8)% and 40 (10)%, respectively. VC recovered more rapidly in Group A.
Postoperative reduction in spirometric volumes was related to BMI. Obesity had more effect on VC than the site of surgery.