Page 6 - CUA2018 Abstracts - Endourology

Poster session 4: Endourology

MP–4.7 Results: There were no baseline characteristic differences between pre–
Routine complete blood count has limited value post– and post–reassembly groups with respect to mean age (52.7 vs. 53.2
percutaneous nephrolithotomy in identifying hemorrhagic or years), Charlson–Comorbidity Index (1.54 vs. 1.53), first time ESWL treat-
infectious complications ment (85 vs. 77%), mean stone size (8.98 vs. 9.59 mm), or stone location
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Tadeusz Kroczak , Michael Ordon , Kenneth Pace , John Honey , Jason Lee 1 (p>0.05). Mean time to post–treatment followup kidney/ureter/bladder
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1 Division of Urology, Department of Surgery, St. Michael’s Hospital, (KUB) imaging was 2.7 and 2.6 weeks in the pre– and post–reassembly
University of Toronto, Toronto, ON, Canada groups. The stone–free rates (30 vs. 49%; p=0.009) and the proportion
Introduction: Percutaneous nephrolithotomy (PCNL) is a minimally inva- experiencing no stone fragmentation (21 vs. 7%; p=0.007) improved
sive procedure with low complication rates reported by high–volume significantly after reassembly. There was no difference in complication
centres; hemorrhage and sepsis rates are typically <5%. Yet, postoperative rates (5 vs. 8%) or proportion requiring subsequent ESWL or ureteroscopy
bloodwork, including complete blood count (CBC), is routinely performed treatments (p>0.05).
in the early postoperative period at most centres. We set out to determine Conclusions: Following the complete disassembly and reassembly of
how effective routine postoperative CBC was in identifying complications our lithotriptor, we detected improvements in early stone–free rates and
after PCNL, as it may represent a low–value care practice. fragmentation effects, with no change in complication rate. Therefore,
Methods: A retrospective chart review was performed of all PCNL proce- an opportunity exists in benchmarking performance standards for SWL
dures at our centre from January 2014 to December 2016. PCNL cases manufacturers and service providers, to ensure function is optimized for
performed on renal transplant patients and percutaneous renal access clinical use.
cases for strictures or urothelial tumours were excluded from the analysis.
Patient demographics and stone characteristics were collected for analysis, MP–4.9
along with postoperative outcome data. Assessing the relationship between obstructive sleep apnea and
Results: Three hundred and eighty–five patients (196 female, 188 males) stone disease
underwent PCNL for urolithiasis. Mean age was 55.8 years, mean Lance Wu , Jamey Marrese , Brooke Pollock , Tim Wollin , Dariusz (Derek)
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American Society of Anesthesiology (ASA) score 2.5, and mean length Bochinski , Trevor Schuler , Shubha De 1
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of stay in hospital 1.74 days (±3.3). Postoperatively, six (1.6%) patients 1 Division of Urology, Department of Surgery, University of Alberta,
required extended stay for CBC monitoring and three (0.8%) patients Edmonton, AB, Canada
required transfusion, one of whom also required angioembolization. Introduction: Though kidney stones are common, obstructive sleep apnea
All patients that required transfusion demonstrated abnormal vital signs (OSA) is also quite prevalent, affecting 20% of the population. Therefore,
(tachycardia and/or hypotension). Of the six patients that required only the objective of this study was to identify the rate of OSA in our patients
extended CBC monitoring, two had abnormal vital signs and four had undergoing shockwave lithotripsy (SWL) and its impact on treatment and
normal vital signs. Mean hospital lengths of stay were 1.6 days, 2.2 days, stone risk.
and 8.8 days for patients with normal postoperative course, requiring Methods: A retrospective review of all SWL patients from Sept 2016–
CBC monitoring, and requiring blood transfusion/angioembolization, June 2017 was performed. At our centre, SWL performed under seda-
respectively. Fourteen patients developed sepsis post–PCNL (3.6%). All tion requires a STOPBANG questionnaire for OSA risk stratification by
of these patients developed abnormal vital signs postoperatively (fever, our respiratory therapist. Low–risk (LR), high–risk (HR), previously diag-
tachycardia, and/or hypotension) and had a mean hospital stay of 5.1 days. nosed and compliant with continuous positive airway pressure (CPAP)
Patients that developed either systemic inflammatory response syndrome (OSA–C), or non–compliant (OSA–NC) groups were then compared.
(SIRS) or sepsis were more likely to have a positive preoperative urine Results: We reviewed 560 patients with an average age of 54 years
culture (p<0.001). and body mass index (BMI) of 29.6; 62% were male. Eighty–five (14.6%)
Conclusions: Routine postoperative CBC after PCNL does not improve were previously diagnosed with OSA. Two hundred fifteen HR and 282 LR
identification of hemorrhagic or infectious complications. Abnormal vital patients were identified, and CPAP compliance was found in 64% of those
signs alone identified all patients that required transfusion or emboliza- previously diagnosed with OSA. OSA–C had the largest stones (73 mm ;
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tion after PCNL and the development of SIRS or sepsis. Length of stay for p=0.01), with no significant difference in number of stones. OSA–NC had
patients undergoing CBC monitoring in the setting of normal vital signs the lowest stone Hounsfield units (p=0.03). LR patients had significantly
was a day longer and resulted in no clinical benefit. lower BMI scores (27.6) (31 HR, 33.3 OSA–NC, 33.9 OSA–NC; p=0.01).
With no significant differences in treatment parameters (shocks, energy
MP–4.8 level, rate) during SWL, fragmentation was found to be significantly more
The effect of extracorporeal shockwave lithotripter reassembly effective in LR. Stone analysis also showed significantly more stones with
on clinical outcomes uric acid in OSA (40 OSA vs. 15 HR vs. 6 LR patients; p=0.031). This is in
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Mark Assmus , Ryan McLarty , Nathan Hoy , Tim Wollin , Trevor Schuler , keeping with metabolic evaluations, where OSA–NC patients had more
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Dariusz (Derek) Bochinski , Shubha De 1 acidic urine (pH5.4; p=0.04), and higher serum uric acid levels (366;
1 Surgery, Division of Urology, University of Alberta, Edmonton, AB, p=0.015). When assessing fragmentation, number of stones, and stone
Canada size, the effect of OSA status on multivariate linear regression models
Introduction: Extracorporeal shockwave lithotripsy (SWL) remains an remained unchanged when age, gender, and metabolic syndrome vari-
effective treatment modality in the armamentarium of the modern endou- ables were included in the model (B 1 18–17.11; p<0.05). However, when
rologist. Currently, there is no industry standards with respect to mainte- BMI was included in the model, OSA became insignificant.
nance and clinical efficacy. Our centre’s fixed SWL unit (Storz Modulith Conclusions: Patients with OSA are over–represented in this kidney stone
SLX) was recently disassembled and transported to a new facility, after cohort. Their treatment efficacy appears to be reduced, and stone risks
which fragmentation appeared to improve anecdotally. Therefore, we are consistent with metabolic syndrome. Ultimately, stone patients should
examined whether stone outcomes were affected by the complete reas- be carefully monitored during/after procedural sedation or general anes-
sembly of our lithotripter. thetic due to their high risk of occult OSA and associated complications.
Methods: A retrospective review of 200 SWL patients was performed.
All patients were treated under sedation by one of five urologists. We
compared two cohorts of 100 patients, before and after transporting the
unit. Patient, stone, and treatment characteristics were recorded, along
with outcome and complication data. Statistical analysis was performed
using a two–tailed, heteroscedastic t–test and Fisher–exact test.
S86 CUAJ • June 2018 • Volume 12(6Suppl2)