Introduction: Outcome prediction tools have the potential to provide
significant adjunctive information for intensivists. Critically ill obstetric and
gynaecology patients constitute a unique subset of the general ICU (intensive
care unit) population yet, there exists no outcome prediction model developed
specifically for these patients.
Objectives: To evaluate the APACHE II score, prospectively develop and
validate an outcome prediction model, evaluate organ failure (Organ Failure
score and SOFA score) and review the SIRS (Systemic Inflammatory
Response Syndrome) response in a cohort of critically ill obstetric and
gynaecology patients.
Design: A prospective study conducted over a 2 year period in the Surgical
ICU at King Edward VIII Hospital, Durban. Institutional ethics approval was
obtained. Patients were allocated to one of the following categories:
Obstetric hypertensive group (Group I), Obstetric non-hypertensive group
(Group II) and Gynaecology group (Group III). Group III was further
subdivided into a pregnant (Group IIIa) and a non-pregnant group (Group
IIIb). Data captured included demographic details, clinical assessment,
investigations, treatment, variables required for calculating the APACHE II
score, organ failure (OF) assessment, SIRS criteria and patient outcome. The
APACHE II system, organ failure assessment and SIRS was evaluated in the
entire patient subset. For the purpose of the outcome prediction model, the
subset was divided into 2 groups: a development group and a validation
group. STATA 7 software was utilised for data analysis.
Results: The dataset comprised 260 inpatients. Obstetrics and gynaecology
cases represented 18.5 % of the total ICU population (n=1408). The majority
of the patients were young (mean age 27 ± 10.5 years). The mean ICU stay
was 5.5 ± 7.9 days. The observed mortality for Groups I, II, III, IIIa and IIIb
was 23.4%, 43.2%, 42.9%, 33.3% and 55.5% respectively. The mean
APACHE II score was significantly higher in nonsurvivors compared to
survivors for all patient subgroups (p< 0.0001). However the APACHE II
system performed variably in each of the 3 groups. The area under the curve
for the ROC curves in each of the 3 main subgroups varied from 0.81 to 0.94
for APACHE II. Groups IIIa and IIIb were too small to permit ROC curve
analysis. Age, mean arterial pressure, respiratory rate, temperature, the
Glasgow Coma Scale score and pH were identified as significant outcome
predictors. Using these parameters an obstetric and gynaecology outcome
prediction (OGOP) model was developed for Groups I, II and III. The area
under the curve for the ROC curves in each of the subgroups was >0.9 for the
OGOP Model. A predictive equation could not be developed for Groups IIIa
and IIIb (due to a small number of admissions in these two groups.) Duration
and the number of organ failures, correlated with outcome. The duration and
number of organ failures associated with mortality differed for each group.
Three OF exceeding 72 hours, 3 OF exceeding 48 hours and 3 OF equal to
48 hours were invariably fatal in Groups I, II and III/IIIa/IIIb respectively. SOFA
scores were significantly higher in nonsurvivors compared to survivors
(p<0.0001). A day one SOFA score equal to 18 (Group I), 15 (Group ll) and 13
(Group III, IIIa, IIIb) was also invariably fatal. A SIRS response was noted in
94.2% of the patient cohort (245/260). The SIRS response varied in the
subgroups. Sterile shock and septic shock were associated with a high
mortality rate. Groups IIIa and IIIb differed with respect to the mean age,
duration of hospital and ICU stay and mortality rate. Although these subsets
were numerically restricted (24 and 18 admissions respectively), the results
suggest that the two subsets are distinctly different in nature.
Comment: The OGOP model is easier to calculate and it is superior to the
APACHE II System. It needs to be validated in other local and international
units. Organ failure assessment as well as the SIRS response provides useful
supplementary outcome information. Although current outcome prediction
tools are not designed for individual application, continued research and
refinement of the available tools, as well as the exploration of novel methods,
may one day result in "near-perfect" prediction estimates and further broaden
the scope of their utility. / Thesis (Ph.D)-University of KwaZulu-Natal, 2006.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ukzn/oai:http://researchspace.ukzn.ac.za:10413/8623 |
| Date | January 2006 |
| Creators | Paruk, Fathima. |
| Contributors | Moodley, Jagidesa. |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
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