Postoperative respiratory failure necessitating transfer to the intensive care unit in orthopedic surgery patients: risk factors, costs, and outcomes

Table 1 Surgical procedures, patient characteristics, and conditions present on admission

Variable	Cases (n = 51)	Controls (n = 153)	p value*
Surgical procedure type
Knee	37 % (19)	37 % (57)
Spine (cervical)	41 % (21)	41 % (63)
Spine (non-cervical)	16 % (8)	16 % (24)
Hip	4 % (2)	4 % (6)
Shoulder	2 % (1)	2 % (3)
Age, years	66 (34–88)	67 (32–90)
Age category, years
31–40	2 % (1)	2 % (3)
41–50	6 % (3)	6 % (9)
51–60	22 % (11)	22 % (33)
61–70	33 % (17)	33 % (51)
71–80	22 % (11)	22 % (33)
81+	16 % (8)	16 % (24)
Male	35 % (18)	35 % (54)
Body mass index (BMI), kg/m²
<25	14 % (7)	17 % (26)	0.67
25.0–29.9	43 % (22)	37 % (56)	0.41
30.0–35.0	18 % (9)	25 % (38)	0.34
>35.0	26 % (13)	22 % (33)	0.57
ASA class
1	0 % (0)	2 % (3)	0.58
2	41 % (21)	69 % (105)	<0.001
3	57 % (29)	29 % (44)	<0.001
4	2 % (1)	1 % (1)	0.44
Conditions present on admission
Asthma	20 % (10)	10 % (16)	0.10
COPD	22 % (11)	3 % (5)	<0.001
OSA	35 % (18)	11 % (17)	<0.001
Obesity (BMI ≥ 30 kg/m²)	43 % (22)	46 % (71)	0.75
CHF	10 % (5)	2 % (3)	0.03
CKD	22 % (11)	6 % (9)	0.002
Restrictive lung disease	4 % (2)	1 % (1)	0.16
Opioid use	41 % (21)	34 % (52)	0.40
Smoking history	57 % (29)	37 % (57)	0.01
Regular use of psychotropic medication	71 % (36)	37 % (56)	<0.001
Diabetes	18 % (9)	11 % (17)	0.23

Results are expressed as mean (range) or percent (n) unless otherwise indicated
ASA American Society of Anesthesiologists, BMI body mass index, COPD chronic obstructive pulmonary disease, OSA obstructive sleep apnea, CHF congestive heart failure, CKD chronic kidney disease
*Fisher’s exact test; p values not shown for matched variables

ISSN: 2047-0525