Postoperative Incidence of Symptomatic Urinary Tract Infection (UTI) and Microbial Pattern Seen in TURP Patients with Negative Cultures Preoperatively

Background: Transurethral Resection of the Prostate (TURP) is the gold standard for surgical treatment of benign prostate hyperplasia (BPH). One of the postoperative complications of TURP is urinary tract infection (UTI). Symptomatic UTI occur despite preoperative sterile urine, prophylactic antibiotics and a closed drainage system. We studied the incidence of such symptomatic UTI and the microbial pattern observed.

Material and Methods: This was a prospective study of 220 patients who had monopolar TURP in our centre from 2015 to 2020. All patients had sterile urine before surgery. Catheters were removed three days postoperatively. Patients presenting with symptoms of UTI were subjected to urine culture and antibiotic sensitivity. The recorded variables include patient demographics, co-morbid factors; Diabetes, hypertension, presence or absence of preoperative catheterization, duration of surgery, presence of postoperative UTI, microbial patterns and antibiotic sensitivity patterns.

Results: The mean age of the patient was 66.25 years. 35.5% had preoperative catheterization. 42 (19%) patients were established to have symptomatic UTI. Age ≥ 65 years, duration of surgery ≥60 mins led to higher infection rates but preoperative catheterization, diabetes and hypertension did not influence UTI rates. The commonest organism was E. Coli and the most common sensitive antibiotic was levofloxacin (quinolone).

Conclusions: Symptomatic UTI post-TURP still occurs despite preoperative sterile urine and routine prophylactic antibiotics.

Introduction

TURP is presently the gold standard for surgical treatment of lower urinary tract symptoms (LUTS) due to benign prostate hyperplasia (BPH) [1]. One of the postoperative complications of this surgical procedure is urinary tract infection (UTI). This can increase the morbidity arising from this surgery and can even lead to mortality from urosepsis if not addressed quickly. Some of the morbidity recorded with post-TURP UTI include persistent haematuria, secondary haemorrhage with clot retention, persistent irritative symptoms and prolonged incontinence.

Unfortunately, meticulous elimination of preoperative UTI in patients with BPH and obtaining sterile urine from culture does not guarantee the absence of postoperative UTI following TURP. This is probably because the prostate itself is an independent source of infection [2]–[4].

We decided to study the incidence of UTI and the microbial pattern seen in patients who were established to have sterile urine preoperatively and also received routine prophylactic antibiotics. This will help to determine the magnitude of the problem and proffer possible interventions to contain this problem.

Methods

This was a prospective study carried out at 82 division military hospitals from 2015 to 2020. 223 patients were recruited into the study. Patients included in the study had Benign prostate hyperplasia (BPH) with indications for TURP. Some presented with urethral catheters in situ because of urine retention. Patients who had suprapubic catheterization, prolonged urethral catheterizations more than 3 days postoperatively, cancer prostate on histology, and bladder stones were excluded from the study.

All had clean catch midstream or catheter-collected urine samples taken for culture and sensitivity in two different designated laboratories prior to surgery. Patients who had positive cultures were subjected to antibiotic treatment based on culture sensitivity and urine cultures were repeated thereafter to establish sterile urine usually three days prior to surgery. Prophylactic antibiotics were given at the start of spinal anaesthesia using intravenous ceftriaxone 1g and gentamycin 80 mg.

Monopolar TURP using 5% dextrose water as irrigation fluid was done for all the patients. Karl Storz size 26 resectoscope was used for prostate resection and achieving excellent haemostasis. Postoperatively normal saline was used for bladder irrigation with a urethral catheter connected to a urine bag in a closed system. Irrigation was continued until the effluent was clear. All bladder irrigations were discontinued within twenty-four hours. The intravenous antibiotics were continued for 48 hours postoperatively. Urethral catheters were removed three days postoperatively and patients who voided normally were discharged home.

Patients were monitored closely and reviewed once a week for features of symptomatic UTI [Symptomatic UTI: Defined as bacteriuria in a patient with symptoms including pain (flank, lower abdominal), lower urinary tract symptoms (dysuria, frequency, urgency, or incontinence, hematuria, or fever)] for 30 days [5]. In between visits, they report any symptoms that may suggest UTI on the phone and they are invited for further evaluation.

Urine samples are taken for culture and sensitivity in patients with suggestive features to establish UTI and document bacteria responsible for infection. Treatment is instituted based on antibiotic sensitivity. The incidence of UTI and patterns of bacteria seen in the cultured urine samples are recorded.

Results

A total of 220 patients completed the study. The mean age of the participants was 66.25 years. patients <65 years of age were 90 and ≥65 years were 130 as depicted in Table I.

Table I. Age Distribution

Variables	Frequency	Percentage	Mean (SD)
Age			66.25 (8.27)
<65 yrs	90
≥65 yrs	130
Total	220	100.0

Patients who were on catheter preoperatively were 78 (35.5%) out of the 220 participants as shown in Table II.

Table II. Presence of Catheter Prior to TURP

	Frequency	Percent
On catheter	78	35.5
Not on catheter	142	64.5
Total	220	100.0

The incidence of UTI in this study was 19.1%. 42 patients out of 220 had symptomatic UTI confirmed on urine culture as shown in Table III.

Table III. Incidence of UTI

Responses	Frequency	Percentage (%)
No	178	80.9
Yes	42	19.1
Total	220	100

Table IV shows the detailed comparison of clinical variables between patients with and those without UTI. Chi-square was used to test for significance between variables.

Table IV. Comparison of Clinical Variables Between Patients with and Those without UTI

Variables	UTI	UTI	Chi-square	P-value
	present	absent
	(n = 42)	(n = 178)
Age			0.004	0.949
<65	17 (40.5)	73 (41.0)
≥65	25 (59.5)	105 (59.0)
Preoperative catheter			0.46	0.498
Yes	13 (31.0)	65 (36.5)
No	29 (69.0)	113 (63.5)
Diabetes			1.171	0.279
Yes	7 (16.7)	19 (10.7)
No	35 (83.3)	159 (89.3)
Hypertension			1.29	0.256
Yes	20 (47.6)	102 (57.3)
No	22 (52.4)	76 (42.7)
Duration of surgery			0.167	0.683
<60 mins	17 (40.5)	66 (37.1)
≥60 mins	25 (59.5)	112 (62.9)

The micro-bacterial pattern observed in this study and their antibiotic sensitivity patterns are depicted in Tables V and VI. Escherichia coli (E. coli) was responsible for 92.8% of the UTI. 28 out of the 39 patients with E. coli infection were susceptible to levofloxacin (quinolone) antibiotic followed by nitrofurantoin in 5 patients with E. coli infection.

Table V. Organisms Cultured

Name of bactria	Frequency	Percentage (%)
Escherichia coli	39	92.8
Streptococcus species	2	4.8
Staphylococcus epidermidis	1	2.4
Total	42	100

Table VI. Antibiotic Sensitivity

Name of bactria	Levofloxacin	Nitrofurantoin	Meropenem	Cefixime
Escherichia coli	28	5	2	4
Streptococcus species				2
Staphylococcus aureus	1

Discussion

UTI has remained a disturbing development in patients who underwent TURP leading to increased morbidity postoperatively. Attempts to reduce the incidence have prompted a meticulous plan to have sterile urine confirmed through urine culture before TURP, placing patients on prophylactic antibiotics and observing sterile conditions postoperatively. However, despite all these, some patients still have UTI with its attendant complications. Some studies have shown that urine cultures are poor indicators of prostatic parenchyma bacterial colonisation. They reported positive prostatic cultures in about one-third of patients undergoing prostate surgery despite sterile preoperative urine cultures [2]–[4].

However, there is no reliable method to determine preoperatively patients with prostate bacterial colonization that will require antibiotic prophylaxis [6].

We decided to study the incidence of symptomatic UTI in our own environment in a sterile preoperative urine culture post-TURP and the possible factors influencing it. In addition, the micro bacterial pattern. The choice of symptomatic UTI is because some studies reported that postoperative bacteriuria is not a risk factor for infectious postoperative complications [7], [8].

The incidence of symptomatic UTI in this study was 19.1%. There is a wide variation in the incidence of UTI post-TURP in literature from 6% to 60% [9], [10]. Hwang et al. [11] reported an incidence of 24% for symptomatic UTI while Colau et al. [12] reported 34.9% for bacteriuria. Studies reporting bacteriuria tend to have a higher incidence. Some studies reported infection rates as low as 3.5% [13] and 1.9% [7].

In this study, patients aged ≥ 65 years were linked to a higher incidence of UTI after TURP but this association was not found to be statistically significant. Some studies found no association with age [12], [14]. However, in some other studies [15], [16], the association was significant and was believed to be linked to immunosenescence, degenerative changes in the prostate and reduced defensive mechanism of the urethral mucosa [16].

A higher UTI rate was not observed in patients with a history of preop catheterization in this study. However, in many studies, the reverse was the case [7], [15], [17], [18]. Some other researchers [6], [19] found no association similar to our study.

Diabetic patients were not observed to have a higher incidence of UTI in this study. This was probably because patients in this study had controlled diabetes before surgery. This explanation is supported by other researchers who found a higher incidence of UTI only in patients with uncontrolled diabetes [6], [15]. Some other studies found an increased incidence of UTI in diabetics but it was not stated if diabetes was controlled or not [7], [11], [14], [18].

Hypertension was also found not to affect the incidence of UTI in our patients. This was similar to a finding in another study [15].

We noted a higher incidence of UTI in patients whose duration of surgery exceeded ≥60 minutes, but this difference was not statistically significant. Most researchers had similar statistically significant results [13]–[15], [18], [20]. A larger sample size may likely show a significant association.

Escherichia coli was responsible for 92.8% of UTIs found in this study. It was the commonest organism found also in most studies [15], [21], [22]. The sensitivity tests showed that E. Coli was sensitive to quinolones (levofloxacin) more than any other antibiotic used. This was also noticed in some studies [22].

Conclusion

Post-TURP UTI is a reality despite preoperative sterile urine and prophylactic antibiotics. All efforts should be made to identify it early and commence appropriate antibiotics based on culture while attempting to modify possible risk factors.