A critical analysis of Discovery Health's claims-based risk adjustment of mortality rates in South African private sector hospitals.

In 2019, Discovery Health published a risk adjustment model to determine standardised mortality rates across South African private hospital systems, with the aim of contributing towards quality improvement in the private healthcare sector. However, the model suffers from limitations due to its design and its reliance on administrative data. The publication's aim of facilitating transparency is unfortunately undermined by shortcomings in reporting. When designing a risk prediction model, patient-proximate variables with a sound theoretical or proven association with the outcome of interest should be used. The addition of key condition-specific clinical data points at the time of hospital admission will dramatically improve model performance. Performance could be further improved by using summary risk prediction scores such as the EUROSCORE II for coronary artery bypass graft surgery or the GRACE risk score for acute coronary syndrome. In general, model reporting should conform to published reporting standards, and attempts should be made to test model validity by using sensitivity analyses. In particular, the limitations of machine learning prediction models should be understood, and these models should be appropriately developed, evaluated and reported.

Compatibility and stability of an admixture of multiple anaesthetic drugs for opioid-free anaesthesia.

The ability to combine and use drugs in a single infusion device may be useful in resource-limited settings. This study examined the chemical stability of an opioid-sparing mixture of ketamine, lidocaine and magnesium sulphate when combined in a single syringe. High-performance liquid chromatography and atomic absorption spectrophotometry were performed on six syringes containing the three-drug mixture. Since most opioid-sparing techniques typically rely on a 24-hour infusion regime, we tested stability at the initial admixing and 24 hours later. Stability was defined as a measured drug concentration within 10% of expected, with the absence of precipitation or pH alterations. Pharmacokinetic simulations were conducted to further show that the achieved plasma drug concentrations were well within an effective analgesic range. All mixed drug concentration measurements were within the required 10% reference limit. No obvious precipitation or interaction occurred, and pH remained stable. Drug stability was maintained for 24 hours. Pharmacokinetic simulations showed that ketamine and lidocaine were within their minimum analgesic effect concentrations. Our results show that this three-drug mixture is chemically stable for up to 24 hours after mixing, with a pharmacokinetic simulation illustrating safe, clinically useful predicted plasma concentrations when using the described admixture.

A prospective observational study of preoperative natriuretic peptide testing in adult non-cardiac surgical patients in hospitals in Western Cape Province, South Africa.

BACKGROUND: International guidelines recommend risk stratification to identify high-risk non-cardiac surgical patients. It is also recommended that all patients aged ≥45 years with significant cardiovascular disease should have preoperative natriuretic peptide (NP) testing. Abnormal preoperative B-type NPs have a strong association with postoperative cardiac complications. In South African hospitals, it is not known how many patients with significant cardiovascular disease scheduled for intermediate- to high-risk surgery will have raised NPs. OBJECTIVES: To determine the prevalence of abnormal (raised) NPs in non-cardiac surgical patients with cardiac clinical risk factors. A secondary objective was to develop a model to identify surgical patients who may benefit from preoperative NP screening. METHODS: The inclusion criteria were patients aged ≥45 years presenting for elective, non-obstetric, intermediate- to high-risk non-cardiac surgery with at least one of the following cardiovascular risk factors: a history of ischaemic heart disease or peripheral vascular disease (coronary equivalent); a history of stroke or transient ischaemic attack; a history of congestive cardiac failure; diabetes mellitus currently on an oral hypoglycaemic agent or insulin; and serum creatinine level >175 µmol/L (>2.0 mg/dL). Blood samples for N-terminal-prohormone B-type NP (NT-proBNP) were collected before induction of anaesthesia. The preoperative prognostic threshold for abnormal (raised) NT-proBNP was ≥300 pg/mL. A generalised linear mixed model was used to determine the association between the risk factors and an abnormal NT-proBNP level. RESULTS: Of 172 patients, 63 (37%) had an elevated preoperative NT-proBNP level. The comorbidities independently associated with elevated preoperative NT-proBNP were coronary artery disease or peripheral vascular disease, congestive cardiac failure, and a creatinine level >175 µmol/L CONCLUSIONS: We strongly recommend that non-cardiac surgical patients aged ≥45 years undergoing intermediate- or high-risk noncardiac surgery with a history of coronary artery disease/peripheral vascular disease, congestive cardiac failure or elevated creatinine have preoperative NP testing as part of risk stratification.

Prophylactic phenylephrine and fluid co-administration to reduce spinal hypotension during elective caesarean section in a resource-limited setting: a prospective alternating intervention study.

Spinal hypotension is a common and clinically important problem during caesarean section. Current consensus recommendations for resource-rich settings suggest the use of a titrated phenylephrine infusion, in combination with fluid coloading, for prevention of maternal hypotension. In resource-limited settings, where syringe drivers are unavailable, these recommendations advise the addition of 500 µg phenylephrine to the first 1 l of intravenous fluid given after initiation of spinal anaesthesia, with additional vasopressor boluses as required. This prospective, alternating intervention study compared the use of a conventional phenylephrine rescue bolus strategy for prevention of hypotension, defined as systolic arterial pressure < 90 mmHg, with a phenylephrine infusion given according to the consensus recommendation. We studied 300 women having elective caesarean section. There were 77 (51%) women who developed hypotension in the bolus group vs. 55 (37%) in the phenylephrine infusion group (p = 0.011). This represented a 29% reduction in hypotension, with a number needed to treat of 6.8. The six highest systolic arterial pressure readings occurred in the phenylephrine infusion group (range 166-188 mmHg), and there were four instances of bradycardia (heart rate < 50 beats.min-1 ) with preserved systolic arterial pressure in each group. There were no adverse clinical sequelae, and no differences in neonatal Apgar scores in either group. The consensus recommendation for phenylephrine and fluid co-administration in resource-limited settings appears effective in preventing maternal hypotension, but at the cost of sporadic systolic hypertension.

A prospective observational study testing liquid crystal phase change type thermometer placed on skin against oesophageal/pharyngeal placed thermometers in participants undergoing general anesthesia.

BACKGROUND: Patient outcomes are influenced by intraoperative temperature management. Oesophageal/pharyngeal temperature monitoring is the standard of care at our institute but is not well tolerated in awake patients. Many non-invasive temperature monitors have been studied. Only the TraxIt® Wearable Children's Underarm Thermometer which contains liquid crystals that undergo phase changes according to temperature is available at our institution. We tested these non-invasive monitors against our standard of care which is the oesophageal/pharyngeal temperature monitor. METHODS: We conducted a prospective observational study of 100 patients receiving general anaesthesia for elective surgery. Patients were eligible for inclusion if they were ≥ 18 years old, were planned to have a general anaesthetic > 60 min during which no body cavity (chest or abdomen) would be opened. Patient temperature was measured with an oesophageal/pharyngeal thermistor probe and skin surface temperature monitors placed over the forehead, in the axilla, over the sternum, and behind the ear (over major vessels to the brain). Temperatures were recorded and then analysed using Altman-Bland plots. Pre-determined clinically relevant limits of agreement were set at -/+ 0.5 °C. RESULTS: From the 100 patients we collected 500 data points for each monitor with an average monitoring time of 102 min (30-300 min) across a range of surgical procedures. None of the skin surface temperature monitors achieved the pre-determined limits of agreement and results were impacted by the use of a forced air warmer. CONCLUSION: The TraxIt® Wearable Children's Underarm Thermometers are not suitable for temperature monitoring during general anaesthesia.

Obstetric spinal hypotension: Preoperative risk factors and the development of a preliminary risk score - the PRAM score.

BACKGROUND: Obstetric spinal hypotension is a common and important problem during caesarean delivery. Identifying patients at risk for hypotension may guide clinical decision-making and allow timeous referral. OBJECTIVE: Using preoperative risk factors, to develop a simple scoring system to predict systolic hypotension. METHODS: This prospective, single-centre, observational study of patients undergoing elective or urgent caesarean delivery assessed body mass index, baseline heart rate, baseline mean arterial pressure (MAP), maternal age, urgency of surgery (elective v. non-elective) and preoperative haemoglobin concentration as predictors of spinal hypotension (systolic blood pressure <90 mmHg). We used empirical cut-point estimations in a logistic regression model to develop a scoring system for prediction of hypotension. RESULTS: From 504 eligible patients, preoperative heart rate (odds ratio (OR) 1.02, 95% confidence interval (CI) 1.00 - 1.03; p=0.012), preoperative MAP (OR 0.97, 95% CI 0.95 - 0.98; p<0.001) and maternal age (OR 1.05, 95% CI 1.02 - 1.08; p=0.002) were found to be predictors of hypotension. We derived a preliminary scoring system (pulse rate >90 bpm, age >25 years, MAP <90 mmHg - the PRAM score) for the prediction of systolic hypotension following obstetric spinal anaesthesia. Patients with three factors had a 53% chance of developing hypotension, compared with the overall incidence of 30%. The PRAM score showed good discrimination, with a c-statistic of 0.626 (95% CI 0.576 - 0.676) and good calibration. CONCLUSIONS: Preoperative heart rate, preoperative MAP and maternal age were predictive of hypotension in elective and emergency caesarean delivery. The PRAM score shows promise as a simple, practical means to identify these patients preoperatively, but requires prospective validation.

Association between preoperative pulse pressure and perioperative myocardial injury: an international observational cohort study of patients undergoing non-cardiac surgery.

BACKGROUND: The management of elevated blood pressure before non-cardiac surgery remains controversial. Pulse pressure is a stronger predictor of cardiovascular morbidity in the general population than systolic blood pressure alone. We hypothesized that preoperative pulse pressure was associated with perioperative myocardial injury. METHODS: This is a secondary analysis of the Vascular Events in Non-cardiac Surgery Patients Cohort Evaluation (VISION) international cohort study. Participants were aged ≥45 yr and undergoing non-cardiac surgery at 12 hospitals in eight countries. The primary outcome was myocardial injury, defined using serum troponin concentration, within 30 days after surgery. The sample was stratified into quintiles by preoperative pulse pressure. Multivariable logistic regression analysis explored associations between pulse pressure and myocardial injury. We accounted for potential confounding by systolic blood pressure and other co-morbidities known to be associated with postoperative cardiovascular complications. RESULTS: One thousand one hundred and ninety-one of 15 057 (7.9%) patients sustained myocardial injury, which was more frequent amongst patients in the highest two preoperative pulse pressure quintiles {63-75 mm Hg, risk ratio (RR) 1.14 [95% confidence interval (CI): 1.01-1.28], P =0.03; >75 mm Hg, RR 1.15 [95% CI: 1.03-1.29], P =0.02}. After adjustment for systolic blood pressure, preoperative pulse pressure remained the dominant predictor of myocardial injury (63-75 mm Hg, RR 1.20 [95% CI: 1.05-1.37], P <0.01; >75 mm Hg, RR 1.25 [95% CI: 1.06-1.48], P <0.01). Systolic blood pressure >160 mm Hg was not associated with myocardial injury in the absence of pulse pressure >62 mm Hg (RR 0.67 [95% CI: 0.30-1.44], P =0.31). CONCLUSIONS: Preoperative pulse pressure >62 mm Hg was associated with myocardial injury, independent of systolic blood pressure. Elevated pulse pressure may be a useful clinical sign to guide strategies to reduce perioperative myocardial injury.

Heart rate variability as a predictor of hypotension following spinal for elective caesarean section: a prospective observational study.

Post-spinal hypotension remains a common and clinically-important problem during caesarean section, and accurate pre-operative prediction of this complication might enhance clinical management. We conducted a prospective, single-centre, observational study of heart rate variability in 102 patients undergoing elective caesarean section in a South African regional hospital. We performed Holter recording for ≥ 5 min in the hour preceding spinal anaesthesia. The low-frequency/high-frequency ratio component of heart rate variability was compared, using a logistic regression model, with baseline heart rate and body mass index (BMI) as a predictor of hypotension (defined as systolic arterial pressure < 90 mmHg) occurring from the time of spinal insertion until 15 min after delivery of the baby. We also assessed clinically relevant cut-point estimations for low-frequency/high-frequency ratio. Low-frequency/high-frequency ratio predicted hypotension (p = 0.046; OR 1.478, 95%CI 1.008-1.014), with an optimal cut-point estimation of 2.0; this threshold predicted hypotension better than previously determined thresholds (p = 0.003; c-statistic 0.645). Baseline heart rate (p = 0.20; OR 1.022, 95%CI 0.988-1.057) and BMI (p = 0.60; OR 1.017, 95%CI 0.954-1.085) did not predict hypotension. Heart rate variability analysis is a potentially useful clinical tool for the prediction of hypotension. Future studies should consider a low-frequency/high-frequency ratio threshold of 2.0 for prospective validation.

Preoperative heart rate and myocardial injury after non-cardiac surgery: results of a predefined secondary analysis of the VISION study.

BACKGROUND: Increased baseline heart rate is associated with cardiovascular risk and all-cause mortality in the general population. We hypothesized that elevated preoperative heart rate increases the risk of myocardial injury after non-cardiac surgery (MINS). METHODS: We performed a secondary analysis of a prospective international cohort study of patients aged ≥45 yr undergoing non-cardiac surgery. Preoperative heart rate was defined as the last measurement before induction of anaesthesia. The sample was divided into deciles by heart rate. Multivariable logistic regression models were used to determine relationships between preoperative heart rate and MINS (determined by serum troponin concentration), myocardial infarction (MI), and death within 30 days of surgery. Separate models were used to test the relationship between these outcomes and predefined binary heart rate thresholds. RESULTS: Patients with missing outcomes or heart rate data were excluded from respective analyses. Of 15 087 patients, 1197 (7.9%) sustained MINS, 454 of 16 007 patients (2.8%) sustained MI, and 315 of 16 037 patients (2.0%) died. The highest heart rate decile (>96 beats min(-1)) was independently associated with MINS {odds ratio (OR) 1.48 [1.23-1.77]; P<0.01}, MI (OR 1.71 [1.34-2.18]; P<0.01), and mortality (OR 3.16 [2.45-4.07]; P<0.01). The lowest decile (<60 beats min(-1)) was independently associated with reduced mortality (OR 0.50 [0.29-0.88]; P=0.02), but not MINS or MI. The predefined binary thresholds were also associated with MINS, but more weakly than the highest heart rate decile. CONCLUSIONS: Preoperative heart rate >96 beats min(-1) is associated with MINS, MI, and mortality after non-cardiac surgery. This association persists after accounting for potential confounding factors. CLINICAL TRIAL REGISTRATION: NCT00512109.

Severe blunt thoracic trauma: differences between adults and children in a level I trauma centre.

BACKGROUND: Trauma is a leading cause of death in the developing world. Blunt thoracic trauma represents a major burden of disease in both adults and children. Few studies have investigated the differences between these two patient groups. OBJECTIVE: To compare mechanism of injury, presentation, management and outcome in children and adults with blunt thoracic trauma. METHODS: Patients were identified from the database of the trauma intensive care unit at Inkosi Albert Luthuli Central Hospital, Durban, South Africa. Demographics and relevant data were extracted from a pre-existing database. RESULTS: Of 415 patients admitted to the unit, 331 (79.7%) were adults and 84 (20.2%) children aged < 18 years. The median injury severity score (ISS) was similar for both age groups (32 v. 34; p = 0.812). Adults had a higher lactate level at presentation (3.94 v. 2.60 mmol/L; p = 0.001). Of the children, 96.4% were injured in motor vehicle collisions, 75.0% as pedestrians. Compared with adults, children had significantly fewer rib fractures (20.2% v. 42.0%; p < 0.001), flail chests (2.4% v. 26.3%; p<0.001) and.blunt cardiac injuries (BCIs) (9.5% v. 23.6%; p = 0.004), but sustained more lung contusions (79.8% v. 65.6%; p = 0.013). Mortality in children was significantly lower than in adults (16.7% v. 27.8%; p = 0.037). CONCLUSION: Thoracic injuries in children are the result of pedestrian collisions more often than in adults. They suffer fewer rib fractures and BCIs, but more lung contusions. Despite similar ISSs, children have significantly lower mortality than adults. More effort needs to be concentrated on child safety and preventing pedestrian injury.

Vasoconstrictor clysis in burn surgery and its impact on outcomes: systematic review and meta-analysis.

AIM: Clysis is the subcutaneous or subdermal injection of a vasopressor containing fluid, with or without local anaesthetic agent, and has been used to limit blood loss in patients undergoing surgical burn management. In this systematic review and meta-analysis we aimed to determine the impact of clysis of a vasoconstrictor on burn patient outcomes. METHODS: We conducted a systematic review to identify trials investigating clysis in burn patients undergoing debridement and/or skin grafting. For each eligible trial we aimed to extract the outcomes of perioperative blood loss, blood transfusion, duration of surgery, graft success and healing time, inflammatory response, sepsis, mortality, duration of hospital stay, catecholamine levels and cardiovascular effects in both the short (<72h) and long term (30 days) after surgery. RESULTS: From 443 citations, we selected 39 for full-text evaluation, and identified 10 eligible trials. Due to a lack of reporting on outcomes of interest, meta-analysis could only be conducted for the outcome of red blood cell (RBC) units transfused per patient. Patients receiving clysis (n=222) were transfused 1.89 less units (95% CI -2.12 to -1.66) as compared to those not receiving clysis, although this was associated with a high degree of heterogeneity (I(2)=88%). CONCLUSION: Few studies have adequately evaluated the impact of clysis in burn surgery on patient important outcomes such mortality, duration of surgery and graft success. These results suggest clysis may reduce the need for blood transfusion but additional high quality research is required.

Blunt cardiac injury in critically ill trauma patients: a single centre experience.

PURPOSE: This study describes the incidence and outcomes of blunt cardiac injury (BCI) in a single trauma intensive care unit (TICU), together with the spectrum of thoracic injuries and cardiac abnormalities seen in BCI. METHODS: We performed a retrospective observational study of 169 patients with blunt thoracic trauma admitted from January 2010 to April 2013. BCI was diagnosed using an elevated serum troponin in the presence of either clinical, ECG or transthoracic echocardiography (TTE) abnormalities in keeping with BCI. The mechanism of injury, associated thoracic injuries and TTE findings in these patients are reported. RESULTS: The incidence of BCI among patients with blunt thoracic trauma was 50% (n=84). BCI patients had higher injury severity scores (ISS) (median 37 [IQR 29-47]; p=0.001) and higher admission serum lactate levels (median 3.55 [IQR 2.4-6.2], p=0.008). In patients with BCI, the median serum TnI level was 2823ng/L (IQR 1353-6833), with the highest measurement of 64950ng/L. TTEs were performed on 38 (45%) patients with BCI, of whom 30 (79%) had abnormalities. Patients with BCI had a higher mortality (32% vs. 16%; p=0.028) and trended towards a longer length of stay (17.0 days [standard deviation (SD) 13.5] vs. 13.6 days [SD 12.0]; p=0.084). CONCLUSIONS: BCI was associated with an increased mortality and a trend towards a longer length of stay in this study. It is a clinically relevant diagnosis which requires a high index of suspicion. Screening of high risk patients with significant blunt thoracic trauma for BCI with serum troponins should be routine practise. Patients diagnosed with BCI should undergo more advanced imaging such as TTE or TOE to exclude significant cardiac structural injury.

The endothelial glycocalyx: a review of the vascular barrier.

The endothelial glycocalyx is an important part of the vascular barrier. The glycocalyx is intimately linked to the homoeostatic functions of the endothelium. Damage to the glycocalyx precedes vascular pathology. In the first part of this paper, we have reviewed the structure, physiology and pathology of the endothelial glycocalyx, based on a literature search of the past five years. In the second part, we have systematically reviewed interventions to protect or repair the glycocalyx. Glycocalyx damage can be caused by hypervolaemia and hyperglycaemia and can be prevented by maintaining a physiological concentration of plasma protein, particularly albumin. Other interventions have been investigated in animal models: these require clinical research before their introduction into medical practice.

Cardiac biomarkers in the prediction of risk in the non-cardiac surgery setting.

B-Type natriuretic peptides and troponin measurements have potential in predicting risk in patients undergoing non-cardiac surgery. Using the American Heart Association framework for the evaluation of novel biomarkers, we review the current evidence supporting the peri-operative use of these two biomarkers. In patients having major non-cardiac surgery who are risk stratified using clinical risk scores, the measurement of natriuretic peptides and troponin, both before and after surgery, significantly improves risk stratification. However, only pre- and postoperative natriuretic peptide measurement and postoperative troponin measurement have shown clinical utility. It is now important for trials to be conducted to determine whether integrating pre- and postoperative natriuretic peptide and postoperative troponin measurement into clinical practice is able to improve clinical outcomes in patients undergoing non-cardiac surgery.

The efficacy of peri-operative interventions to decrease postoperative delirium in non-cardiac surgery: a systematic review and meta-analysis.

The purpose of this meta-analysis was to determine the efficacy of peri-operative interventions in decreasing the incidence of postoperative delirium. An electronic search of four databases was conducted. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were adhered to. We included randomised controlled trials of non-cardiac surgery with a peri-operative intervention and that reported postoperative delirium, and identified 29 trials. Meta-analysis revealed that peri-operative geriatric consultation (OR 0.46, 95% CI 0.32-0.67) and lighter anaesthesia (OR 2.66, 95% CI 1.27-5.56) were associated with a decreased incidence of postoperative delirium. For the other interventions, the point estimate suggested possible protection with prophylactic haloperidol (OR 0.62, 95% CI 0.36-1.05), bright light therapy (OR 0.20, 95% CI 0.03-1.19) and general as opposed to regional anaesthesia (OR 0.76, 95% CI 0.47-1.23). This meta-analysis has shown that peri-operative geriatric consultations with multicomponent interventions and lighter anaesthesia are potentially effective in decreasing the incidence of postoperative delirium.

The incidence and outcomes of acute kidney injury amongst patients admitted to a level I trauma unit.

PURPOSE: This study aimed to identify the incidence and outcomes of patients with trauma related acute kidney injury (AKI), as defined by RIFLE criteria, at a single level I trauma centre and trauma ICU. METHODS: We performed a retrospective observational study of 666 patients admitted to a trauma ICU from a level I trauma unit from March 2008 to March 2011. We conducted multivariable logistic regression to identify independent predictors for AKI and mortality. RESULTS: The overall incidence of AKI was 15% (n=102). Median injury severity score (ISS) was 25 (inter quartile range [IQR] 16-34) and mean age was 39 (SD 16.3) in the AKI group. Thirteen patients (13%) were referred with rhabdomyolysis associated renal Failure. Overall mortality in the AKI group was 57% (n=58) but was significantly lower in the rhabdomyolysis Failure group (23% versus 64%; p=0.012). AKI was independently associated with older age, base excess (BE)<-12 (odd ratio [OR] 22.9, 95% confidence interval [CI] 1.89-276.16), IV contrast administration (OR 2.7 95% CI 1.39-5.11) and blunt trauma (OR 2.2 95% CI 1.04-4.71). AKI was an independent predictor of mortality (OR 8.5, 95% CI 4.51-15.95). Thirty-nine (38%) patients required renal replacement therapy. CONCLUSIONS: AKI in critically ill trauma patients is an independent risk factor for mortality and is independently associated with increasing age and low BE. Renal replacement therapy utilisation is high in this group and represents a significant health care cost burden.

The role of non-invasive ventilation in blunt chest trauma: systematic review and meta-analysis.

PURPOSE: Respiratory support is the mainstay for the management of patients with pulmonary contusion following blunt chest trauma. In patients not requiring immediate intubation and ventilation, the optimal respiratory management strategy is not clear. This systematic review and meta-analysis aimed to determine the efficacy of non-invasive ventilation (NIV), as compared to traditional respiratory support strategies (i.e., high-flow facemask oxygen or pre-emptive intubation and ventilation), in adult patients with blunt chest trauma. METHODS: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing NIV to traditional forms of respiratory support (i.e., facemask oxygen or intubation and ventilation) in an adult trauma population. For each eligible trial, we extracted the outcomes of all-cause mortality, length of intensive care unit (ICU) stay, length of hospital stay, and pneumonia. RESULTS: We identified 643 citations, selected 17 for full-text evaluation, and identified three eligible RCTs. Patients receiving NIV had a non-significant reduction in the risk of death (OR 0.55; 95 % CI 0.18-1.70; I (2) = 0 %), but significant reductions in length of ICU stay (mean difference -2.45 days; 95 % CI -4.27 to -0.63; I (2) = 66 %), length of hospital stay (mean difference -4.60 days; 95 % CI -8.81 to -0.39; I (2) = 85 %), and risk of pneumonia (OR 0.20; 95 % CI 0.09-0.47; I (2) = 0 %). CONCLUSION: This meta-analysis suggests that NIV is superior to both high-flow facemask oxygen or pre-emptive intubation and ventilation in patients with blunt chest trauma who have no contraindication to NIV.

Utility of B-type natriuretic peptides in preeclampsia: a systematic review.

BACKGROUND: Preeclampsia and its complications may be associated with elevated B-type natriuretic peptide levels during and after pregnancy. METHODS: We conducted a systematic review to determine whether preeclampsia and/or related cardiovascular complications, eclampsia and preterm delivery are associated with elevated natriuretic peptide levels. Three bibliographic databases were searched, using the terms "natriuretic peptide", "pregnancy", "preeclampsia", "eclampsia" and "BNP". Twelve studies fulfilled our inclusion criteria for full paper analysis. The data were too heterogeneous to allow for meaningful quantitative analyses. RESULTS: In healthy patients, B-type natriuretic peptide levels did not change during pregnancy. Compared with normal pregnancies, preeclamptic patients were shown to have significantly higher natriuretic peptide levels in the third trimester, which remained elevated for 3-6 months postpartum. Several papers suggested that cardiovascular dysfunction in preeclampsia is associated with NP elevation. Abnormalities were elevated systemic vascular resistance and cardiac filling pressures, decreased cardiac output, left ventricular diastolic dysfunction, and elevated left ventricular mass index. One investigation found that natriuretic peptide levels were higher in preeclamptic women who subsequently had preterm delivery, compared with those who delivered after 34 weeks. There were no data on natriuretic peptide levels in eclampsia. CONCLUSIONS: Preeclampsia is associated with elevated natriuretic peptide levels. Cardiovascular complications and preterm delivery in this setting may also be associated with elevated natriuretic peptide levels. Large prospective studies of natriuretic peptide measurement in preeclampsia are needed to determine whether elevated levels predict the development of severe preeclampsia and/or associated complications.