Postoperative mortality after inpatient surgery: Incidence and risk factors

Figures & data

Table 1 Hospital deaths after inpatient surgeriesa

	Inpatient surgeries n = 12,739
Death within 48 hours
Incidence	72 (0.57%)
Mortality rate	1:177
Death within 30 days
Incidence	262 (2.1%)
Mortality rate	1:49

Notes: ^aOver the sampling period of 4/1/04–3/31/05, 12,739 inpatient surgical procedures. The table lists the cumulative incidence (frequency and percent) of hospital deaths, and the overall mortality rate, over two time periods, 48 hours and 30 days after surgery.

Figure 1 Risk factors for 48 h and 30 d postoperative mortality. For each panel, the y-axis shows the incidence of mortality (%) 48 h or 30 d postoperatively, and the x-axis shows the ASA PS of the patient (A; 1–5 scale), the patient’s age (B; years), the emergency status of the operation (C), whether the operation was a trauma case (D), whether the patient was hypothermic perioperatively (E), whether a perioperative adverse event occurred (F), and whether the operation resulted in postoperative intensive care unit admission (G). In some panels, the exact percentage is noted with an arrow (eg, “0” refers to “0%”).

Notes: The figure legends list the significance levels from chi-square or Fisher’s exact test examining incidence rates across each level of the risk factor.
Abbreviations: ASA PS, American Society of Anesthesiologists physical status; d, day; h, hour; NS, not significant.

Figure 2 Risk factors for 48 h and 30 d postoperative mortality. For each panel, the y-axis shows the incidence of mortality (%) 48 h or 30 d postoperatively, and the x-axis shows the anesthesia type (A; MAC, regional anesthesia, general anesthesia or combined), the total time under anesthesia care (B; minutes), the use of invasive monitoring via arterial line (C), cardiovascular catheter (D) or pulmonary artery catheter (E), and whether the operation involved deliberate intraoperative hypotension (F). In some panels, the exact percentage is noted with an arrow (eg, “0” refers to “0%”).

Notes: The figure legends list the significance levels from chi-square or Fisher’s exact test examining incidence rates across each level of the risk factor.
Abbreviations: d, day; h, hour; MAC, monitored anesthesia care; NS, not significant.

Table 2 Generalized estimating equations model for 48 hour and 30 day postoperative mortalitya

	Coefficient (B)	Standard Error	p valueb	Exp(B)c	95% CI for Exp(B)d
48 hour postoperative mortality
ASA PS	2.26	0.60	p < 0.0005	9.57	2.97–30.85
Age	0.57	0.27	p < 0.05	1.75	1.04–2.98
Emergency Operation	2.06	0.27	p < 0.0005	7.81	4.57–13.34
Trauma	0.19	0.53	N. S.	1.21	0.43–3.43
Perioperative Hypothermia	0.30	0.47	N. S.	1.36	0.54–3.43
Perioperative Adverse Event	2.48	0.31	p < 0.0005	11.91	6.46–21.96
Postoperative ICU Admission	0.88	0.31	p < 0.01	2.42	1.32–4.43
Total time under Anesthesia Care	0.52	0.37	N. S.	1.67	0.81–3.45
Anesthesia type	1.06	0.71	N. S.	2.90	0.72–11.75
Deliberate Hypotension	0.49	1.28	N. S.	1.64	0.13–20.09
Arterial Line	−0.47	0.37	N. S.	0.62	0.30–1.28
Cardiovascular Catheter	0.66	0.43	N. S.	1.93	0.83–4.49
Pulmonary artery Catheter	−0.57	0.45	N. S.	0.56	0.23–1.37
30 day postoperative mortality
ASA PS	2.72	0.37	p < 0.0005	15.20	7.31–31.56
Age	0.59	0.14	p < 0.0005	1.79	1.37–2.35
Emergency Operation	1.18	0.15	p < 0.0005	3.25	2.42–4.37
Trauma	0.36	0.31	N. S.	1.43	0.78–2.61
Perioperative Hypothermia	0.15	0.29	N. S.	1.17	0.66–2.06
Perioperative Adverse Event	1.37	0.25	p < 0.0005	3.92	2.41–6.37
Postoperative ICU Admission	1.09	0.15	p < 0.0005	2.96	2.19–4.00
Total Time Under Anesthesia Care	−0.08	0.19	N. S.	0.93	0.64–1.36
Anesthesia type	1.20	0.39	p < 0.01	3.32	1.54–7.16
Deliberate Hypotension	−0.68	1.06	N. S.	0.50	0.06–4.03
Arterial line	−0.02	0.18	N. S.	0.98	0.69–1.39
Cardiovascular Catheter	0.08	0.25	N. S.	1.09	0.67–1.77
Pulmonary artery Catheter	−0.66	0.30	p < 0.05	0.52	0.29–0.93

Notes: ^aThe table lists the results of the Generalized Estimating Equations model, with risk factors of ASA PS (3,4,5 vs. 1,2), age (0–1 or 65+ years vs. 2–64 years), emergency procedure (yes vs. no), trauma (yes vs. no), preoperative hypothermia (yes vs. no), perioperative adverse event (yes vs. no), ICU admission postoperatively (yes vs. no), total time under anesthesia care (top 25% vs. bottom 75%), anesthesia type (general vs. MAC, regional or combined for death within 48 h; general or MAC vs. regional or combined for death within 30 days), and invasive monitoring via arterial line, cardiovascular catheter or pulmonary artery catheter (yes vs. no);

^b“N.S. stands for that significant.”;

^cExp(B) is an estimate of the odds ratio for each risk factor;

^d95% Confidence Intervals (CI) are provided for each Exp(B) estimate.

Abbreviations: ASA PS, American Society of Anesthesiologists physical status; d, day; h, hour; ICU, intensive care unit; MAC, monitored anesthesia care; NS, not significant.