Risk Factors of Gootjies et al for Postoperative Stupor and Coma

 

Patient selection: surgery under general anesthesia

 

Parameters:

(1) age

(2) comorbidity

(3) type of surgery

(4) intra-operative hypotension (systolic blood pressure < 80 mm Hg)

 

Comorbid conditions included:

(1) chronic obstructive pulmonary disease (COPD)

(2) carotid artery disease

(3) previous stroke or transient ischemic attack

(4) congestive heart failure

(5) hypertension

(6) diabetes mellitus

Parameter	Finding	Points
age	not elderly (< 69 years of age)	0
	elderly (>= 69 years of age)	1
significant comorbidity	none	0
	present	1
type of surgery	noncardiovascular	0
	cardiovascular (cardiothoracic or vascular)	1
intra-operative hypotension	none	0
	present	1

 

where:

• Intra-operative hypotension was considered persistent if it lasted >= 10 minutes.

• The age ranges for the affected and control group overlapped. The mean age for the affected group was 69 years, which I will use for the valid in the implementation.

• Some of the patient undergoing cardiovascular procedures were on a bypass machine, which is associated neurologic complications. However, I could not find this discussed as a risk factor. It might be interesting to include this as a separate risk factor.

• The total number of significant comorbid conditions could affect the risk.

• I did not see cancer listed as a serious comorbid condition.

 

total number of risk factors =

= SUM(points for all 4 patients)

 

Interpretation:

• minimum number of risk factors: 0

• maximum number of risk factors: 4

• The risk of postoperative stupor and coma increases with the number of risk factors.

 

Ways to reduce risk:

(1) If the comorbid condition is reversible or treatable, then delay surgery if possible.

(2) Avoid unnecessary cardiovascular surgery in an elderly person with cardiovascular disease.

(3) Avoid hypotension during surgery and minimize its duration.

 

Limitations:

• This study does not include rare causes of stroke in the perioperative period (dissection of a vertebral artery, air embolism, patent foramen ovale, etc.).