Department of surgery,
University of california, Irvine
Diminished lung volume and hypoxemia
following laparotomy or thoracotomy, progressing
to clinically significant pulmonary
complications, are not unusual. A major cause of
progressive alveolar collapse is the abnormal
pattern of ventilation characteristic of the
postoperative period: shallow tidal breathing
without spontaneous deep breaths. A respiratory
maneuver should include high alveolar inflating
pressure (preferably negative intrathoracic
pressure) applied for a long time, achieving the
maximum inspired volume to prevent or treat
atelectasis. Voluntary sustained maximal
inspiration (SMS) with the glottis open (a yawn)
is the ideal maneuver (1), but is difficult to
induce in patients. A device which assures these
conditions was used to quantitate the
physiologic effects of the maneuver. SMI
reverses the alterations in postoperative
pulmonary function (2). The purpose of this
study was to determine if regular voluntary
yawning using the device could decrease the
incidence of pulmonary complications.
APPARATUS AND METHODS
The incentive spirometer assures
reproducible SMI to total lung volume, rewards
the patient with a light signal, and records
each SMI maneuver. One hundred adults
consecutively undergoing elective laparotomy
were randomly placed in a treated or control
group with the exception that those with chronic
pulmonary disease were selected for the treated
group. Hospital staff carried out deep
breathing, coughing, and early ambulation in all
patients, and suctioning, drug administration,
blood gases and assisted ventilation as
indicated. Temperature, vital signs, sputum
production, physical findings, and vital
capacity were recorded daily by the
investigators. Chest x-rays were done
pre-operatively and on the second and fourth
postoperative days. Patients in the treated
group were instructed preoperatively in use of
the spirometer and encouraged to yawn at least
10 >< an hour after operation. There was
no difference between the treated versus control
groups in average age (50 vs. 48), pre-op vital
capacity (2718 vs. 2637), days of nasogastric
tube (1.7 vs. 2.3), anesthesia time or agent,
type of operation or incision.
RESULTS
X-ray abnormalities developed
postoperatively in 48% of control and 30% of
treated patients. Pulmonary complications were
defined as fever over 100°, sputum
production, abnormal physical findings, and
abnormal chest x-ray. Pulmonary complications
developed in 15 control patients (30%) and 5
treated patients (10%). Among the 15 control
patients with complications, 11 required
antibiotics, 10 suctioning, and one assisted
ventilation. Seven patients were hospitalized
for more than 10 days after operation. Of the 5
treated patients with pulmonary complications, 1
required antibiotics, 1 suctioning, and none
assisted ventilation. One patient was
hospitalized for more than 10 days after
surgery. One of these 5 developed atelectasis
secondary to pleural effusion following
splenectomy, 2 developed lobar atelectasis on
the second day, re-expanded by the fifth day,
and 2 were elderly females who had difficulty
using the device, averaging 35 yawns per day.
[Average for the group, 140 (15-650)].
The SMI maneuver has also been used successfully
to treat 10 patients with established
atelectasis unresponsive to conventional
management.
CONCLUSIONS
Although many maneuvers and devices have
been proposed to prelent pulmonary
complications, only deep breathing has been
consistently effective (3). The incentive
spirometer assures reproducible sustained
maximal inspiration, is well accepted by
patients, and records the frequency of the
prescribed breathing exercises. Altering the
pattern of ventilation to include regular SMI
(yawning) with an incentive spirometer reduced
the incidence of postoperative pulmonary
complications in this study from 30% to
10%.
REFERENCES
1. Ward RS, Danziger F, Bonica jj, et al: An
evaluation of postoperative respiratory
maneuvers. Surg Gynecol Obstet 123:51, 1966
3. Bartlett RH: Post-Traumatic Pulmonary
Insufficiency. Surgery Annual. New York,
Appleton Century Crofts, 1971
4. Cahill CA
Yawn maneuver to prevent atelectasis AORN 1978;
27; 5; 1000-1004
5. Crosby
L; Parsons LC Clinical neurologic assessment
tool: development and testing of an instrument
to index neurologic status.Heart Lung 1988; 18;
2; 121-9
