Prediction of hematocrit decline and the impact of peri-operative fluid use in lumbar spinal fusion surgery.

PURPOSE: Peri-operative blood loss unaccounted for and post-operative hematocrit decline could have a significant impact on the outcome of elective spinal surgery patients. The study assesses the accuracy of predictive models of hematocrit decline and blood loss in spinal surgery and determines the impact of peri-operative fluid administration on hematocrit levels of patients undergoing first-time single level lumbar fusion surgery for degenerative spine disease and the trend thereof in the first 24 h post-operatively. METHODS: Clinical and biochemical parameters were prospectively collected in patients undergoing single level lumbar spinal surgery. Predictive models were applied to assess their accuracy in intra-operative blood loss and post-operative hematocrit decline. RESULTS: High correlation (0.98 Pearson correlation coefficient) occurred between calculated (predicted) and recorded hematocrit from hours 2 to 6 post-operatively. Predictive accuracy declined thereafter yet remained moderate. Patients received an average intra-operative fluid volume of 545.45 ml per hour (47% of estimated total blood volume). A significant hematocrit decline occurred post-induction (43.47-39.78%, p < 0.001) with total fluid volume received being the significant contributing variable (p < 0.001). Hypertensive patients were the only subgroup to drop below the safe hematocrit threshold of 30%. CONCLUSION: Iatrogenic hemodilution can accurately be predicted for the first six hours post-operatively, with high risk patients identifiable. Fluid therapy should be goal directed rather than generic, and good communication between the surgeon and anesthesiologist remains the cornerstone to manage physiological changes secondary to blood loss. Although helpful, predictive formulas are not universally applicable to all phenotypes.

Incidence of spine surgery in the South African private healthcare sector: ten-year trends within a large open medical scheme.

PURPOSE: Studies from developed countries suggest a dramatic increase in the utilization of spine surgery in recent decades, however less is known about spine surgery rates in the developing world. The aim of this study was to investigate ten-year trends in the incidence of spine surgery within South Africa's largest open medical scheme. METHODS: This retrospective review included adult inpatient spine surgeries funded by the scheme between 2008 and 2017. The incidence of spine surgery was investigated by age group-overall and for degenerative pathologies, fusion and instrumentation. Surgeons per 100,000 members were determined. Trends were evaluated by linear regression and by crude 10-year change in incidence. RESULTS: A total of 49,575 spine surgeries were included. The incidence of surgery for lumbar degenerative pathology showed a significant upward trend among 60-79 year olds but declined among 40-59 year olds. The incidence of lumbar fusion and lumbar instrumentation declined significantly among 40-59 year olds with little change among 60-79 year olds. The ratio of orthopaedic spinal surgeons decreased from 10.2 to 6.3 per 100,000 members whereas the ratio of neurosurgeons decreased from 7.6 to 6.5 per 100,000. CONCLUSION: Spine surgery in the South African private healthcare sector bears some similarity to developed countries in that it is dominated by elective procedures for degenerative pathology. However, the findings did not reflect the marked increases in the utilization of spine surgery reported elsewhere. It is hypothesized that this may be partly related to differences in the supply of spinal surgery.

Evaluation of locally manufactured patient-specific custom made implants for cranial defects using a silicone mould.

BACKGROUND: Cranial vault defects can pose a significant problem for neurosurgeons where autologous bone is no longer available for cranioplasty. Numerous materials exist to create implants which include polymethyl methacrylate (PMMA) and titanium. A technique using 3-dimensional CT scan reconstruction of a cranial defect and creating a silicon mould which can be autoclaved in theatre to create a PMMA implant was developed. OBJECTIVE: The aim of this study is to evaluate the efficacy, cosmetic result, safety and cost-effectiveness of this procedure and compare this to existing techniques. METHOD: An ambispective study was performed in patients requiring cranioplasty with a custom made implant. Patients were assessed for risk factors and cosmetic outcome, surgical technique was described and complications and cost compared to existing literature between 2010 and 2016. RESULTS: Thirty retrospective and 30 consecutive prospective patients were recruited into the study. Overall sepsis rate was 8.3%. All septic cases had superficial sepsis of which 2 grafts were removed due to cerebrospinal fluid leakage resulting in wound breakdown. A 100% accurate implant to defect ratio was achieved leading to a high satisfaction rate. Average cost was 5 times cheaper than the closest market related product. CONCLUSION: Patient specific moulds using PMMA to create custom implants are safe, have excellent cosmetic results and are a very cost-effective option to manage cranial defects. Accurate planning strategies for large craniotomies, where bone will potentially be discarded, add to surgical effectiveness and cost-saving to the patient.

CSF protein concentration associated with ventriculoperitoneal shunt obstruction in tuberculous meningitis.

INTRODUCTION: Hydrocephalus occurs in 85% of patients with tuberculous meningitis (TBM). Ventriculoperitoneal shunt (VPS) insertion is first-line treatment for relieving increased intercranial pressure. VPS obstruction secondary to increased protein levels in cerebrospinal fluid (CSF) is a known complication. OBJECTIVE: To ascertain if there is a difference in protein levels 1) between cranial and lumbar CSF, and to quantify levels associated with VPS obstruction, and 2) obtained from lumbar puncture vs. ventricular CSF. METHOD: A 30-year retrospective analysis was undertaken. CSF protein levels were statistically analysed to determine correlation between these levels and VPS obstruction. RESULTS: Of 214 children and 376 adults who underwent VPS insertion for TBM, respectively 27.5% and 25.5% sustained blocked VPS. The mean protein level in CSF collected from the non-obstructed group was 1.76 g/l, compared to 2.94 g/l in the obstructed group. The mean CSF protein level from intraoperative ventricular vs. lumbar puncture samples in the VPS obstruction group was respectively 2.471 g/l and 2.474 g/l. CONCLUSION: Patients with increased protein levels in CSF are at a high risk of VPS blockage. In these patients, temporary measures should be employed until CSF protein levels decrease.

Evaluation of locally manufactured patient-specific custom made implants for cranial defects using a silicone mould

Background: Cranial vault defects can pose a significant problem for neurosurgeons where autologous bone is no longer available for cranioplasty. Numerous materials exist to create implants which include polymethyl methacrylate (PMMA) and titanium. A technique using 3-dimensional CT scan reconstruction of a cranial defect and creating a silicon mould which can be autoclaved in theatre to create a PMMA implant was developed. Objectives: The aim of this study is to evaluate the efficacy, cosmetic result, safety and cost-effectiveness of this procedure and compare this to existing techniques.Methods: An ambispective study was performed in patients requiring cranioplasty with a custom made implant. Patients were assessed for risk factors and cosmetic outcome, surgical technique was described and complications and cost compared to existing literature between 2010 and 2016.Results: Thirty retrospective and 30 consecutive prospective patients were recruited into the study. Overall sepsis rate was 8.3%. All septic cases had superficial sepsis of which 2 grafts were removed due to cerebrospinal fluid leakage resulting in wound breakdown. A 100% accurate implant to defect ratio was achieved leading to a high satisfaction rate. Average cost was 5 times cheaper than the closest market related product.Conclusion: Patient specific moulds using PMMA to create custom implants are safe, have excellent cosmetic results and are a very cost-effective option to manage cranial defects. Accurate planning strategies for large craniotomies, where bone will potentially be discarded, add to surgical effectiveness and cost-saving to the patient

Shallow-water spinal injuries--devastating but preventable.

BACKGROUND: Shallow-water diving injuries have devastating consequences for patients and their families, requiring intensive use of resources in both the acute and rehabilitative phases of injury. With the final clinical outcome often poor, the question is raised as to whether a target group can be identified for whom to implement a preventive programme. OBJECTIVE: To evaluate the demographics, clinical features and outcomes of shallow-water diving injuries in an acute spinal cord injury (ASCI) unit. MATERIALS AND METHODS: All patients admitted to the ASCI unit with diving-related injuries were entered into the study. Data regarding demographics, injury profile and subsequent management were collated. All case notes and X-rays were reviewed. Ethical approval was obtained. RESULTS: Forty-six patients were reviewed from 19 April 2003 to 8 February 2009. A steady annual increase in diving injuries was noted. A very specific patient profile was identified: 91% male incidence, average age 23 years, 37% admitted alcohol use, with a summer-time prevalence. Compression-flexion type injuries were most prevalent, with an orthopaedic level of C5 and neurological level of C4 being the most common injury sites. A third of diving injuries occurred in the sea, 20% in swimming pools, 20% in rivers, 11% in tidal pools and 4% in dams. CONCLUSION: A very specific patient profile was identified, and the severity of shallow-water diving injuries was confirmed. No current preventive programme exists except for a single television advertisement. These data will be used to motivate further educational and preventive programmes for reducing the incidence of diving-related injuries.