Variability in Surgical Caseload and Access to Intensive Care Services

Background: Variability in the demand for any service is a significant barrier to efficient distribution of limited resources. In health care, demand is often highly variable and access may be limited when peaks cannot be accommodated in a downsized care delivery system. Intensive care units may frequently present bottlenecks to patient flow, and saturation of these services limits a hospital's responsiveness to new emergencies.

Methods: Over a 1-yr period, information was collected prospectively on all requests for admission to the intensive care unit of a large, urban children's hospital. Data included the nature of each request, as well as each patient's final disposition. The daily variability of requests was then analyzed and related to the unit's ability to accommodate new admissions.

Results: Day-to-day demand for intensive care services was extremely variable. This variability was particularly high among patients undergoing scheduled surgical procedures, with variability of scheduled admissions exceeding that of emergencies. Peaks of demand were associated with diversion of patients both within the hospital (to off-service care sites) and to other institutions (ambulance diversions). Although emergency requests for admission outnumbered scheduled requests, diversion from the intensive care unit was better correlated with scheduled caseload (r = 0.542, P < 0.001) than with unscheduled volume (r = 0.255, P < 0.001). During the busiest periods, nearly 70% of all diversions were associated with variability in the scheduled caseload.     

A prospective two-month audit of the lack of provision of a high-dependency unit and its impact on intensive care

All admissions into a six-bedded intensive care unit were audited prospectively over a 2-month period. Data were collected daily and classified according to criteria for intensive care or high-dependency admission. There were 30 planned admissions (72 bed days) following elective major surgery, seven admissions following semi-elective surgery (41 bed days) and 47 emergency admissions (185 bed days). Overall bed occupancy was 89%. Of 366 possible intensive care days, 66 (23%) were occupied by high-dependency patients. Of the planned admissions all but five were discharged within 2 days. There were 39 major complications during the study period requiring life-saving interventions and 16 lesser but significant complications. In 12% of patients discharge was delayed because of the absence of a high-dependency unit. Four patients were transferred to an intensive care unit in another hospital and four patients were discharged prematurely because other patients required urgent admission. Seven patients were refused admission and three patients scheduled for elective operations had their surgery deferred. We estimate that over the study period 22 additional patients could have been cared for if a high-dependency unit existed.     

Changing neurosurgical workload in the United States, 1988-2001: craniotomy other than trauma in adults

OBJECTIVE: Changes in neurosurgical workload can justify requests for hospital resources and guide planning by neurosurgical training programs. Most previous studies have used non-population-based data sources, such as surveys of professional society members, to explore the neurosurgical workload in the United States. METHODS: This is a retrospective cohort study of patients in Diagnosis Related Group (DRG) 1 ("Craniotomy other than trauma, age > 17") using the Nationwide Inpatient Sample. Statistical methods were adjusted for complex survey methodology to generate total United States caseload estimates. RESULTS: The total United States DRG 1 caseload increased from 70,800 admissions in 1988 to 105,300 admissions in 2001, a 50% relative increase (P < 0.001). For most diagnostic categories, the relative caseload increase was similar to that for the whole group. Patient age and sex distributions remained stable over time. Medical comorbidities, such as hypertension, chronic pulmonary disease, diabetes, and obesity, became more frequent. Elective admissions increased and in-hospital mortality rates decreased. Length of hospital stay decreased during the first half of the study period and then stabilized. Combined with increasing caseload, this caused total annual inpatient DRG 1 days to increase progressively after 1996. The number of United States hospitals with DRG 1 admissions decreased over time. Per-hospital annual DRG 1 caseloads increased, especially at high-volume centers. For the largest 100 hospitals by DRG 1 caseload, total admissions increased from 8.5% of all United States admissions (1988) to 9.4% (2001), whereas DRG 1 caseload increased disproportionately, from 27% to 38% of the United States aggregate caseload. This is evidence that progressive centralization of DRG 1 admissions took place during the study period. CONCLUSION: We documented an increase in total caseload and centralization of care for DRG 1 in the United States during the period 1988 to 2001. Defining the reasons for the changes in neurosurgical workload we observed will require further research.     

The workload of a surgical unit in a district general hospital.

A 3-month prospective study of the workload of a surgical unit in a district general hospital was performed to identify the relationship between outpatient work, admissions to hospital, and scheduled operating lists. We have shown that under 60% of all new cases seen in the outpatient clinic had admissions arranged after initial consultation. Over two-thirds of inpatient admissions were for emergencies or urgent cases, and thus not able to be controlled by the surgical team. One-third of emergency admissions had an operation within 24 h of admission. One third of the total number of cases on scheduled lists were emergency or urgent cases (taking up approximately 50% of the operating time). Of all admissions, 32% were as day cases. Of all routine operations, 35% were performed at a community hospital taking only 18% of all our admissions.     

Critically ill obstetric patients in the intensive care unit

We aimed to determine the morbidity and mortality among obstetric patients admitted to the intensive care unit. In this study, we analyzed retrospectively all obstetric admissions to a multi-disciplinary intensive care unit over a five-year period. Obstetric patients were identified from 4733 consecutive intensive care unit admissions. Maternal age, gestation of newborns, mode of delivery, presence of coexisting medical problems, duration of stay, admission diagnosis, specific intensive care interventions (mechanical ventilation, continuous veno-venous hemofiltration, central venous catheterization, and arterial cannulation), outcome, maternal mortality, and acute physiology and chronic health evaluation (APACHE) II score were recorded. Obstetric patients (n=125) represented 2.64% of all intensive care unit admissions and 0.89% of all deliveries during the five-year period. The overall mortality of those admitted to the intensive care unit was 10.4%. Maternal age and gestation of newborns were similar in survivors and non-survivors. There were significant differences in length of stay and APACHE II score between survivors and non-survivors P < 0.05. The commonest cause of intensive care unit admission was preeclampsia/eclampsia (73.6%) followed by post-partum hemorrhage (11.2%). Intensive care specialists should be familiar with these complications of pregnancy and should work closely with obstetricians.     

Multicentre study of validity and interrater reliability of the modified Nursing Care Recording System (NCR11) for assessment of workload in the ICU

BACKGROUND: Reliable assessment of nursing workload is necessary for the quantitative approach to staffing of intensive care units. The Nursing Care Recording System (NCR11) scores both the nursing contribution to patient care and those related to medical procedures. The purpose of the present work was to compare NCR11 scoring with the Therapeutic Intervention Scoring System (TISS) and Nine Equivalents of Nurse Manpower use Score (NEMS) and to examine the interrater reliability of NCR11 scoring. METHODS: Bias and precision of workload scores (NCR11 vs. TISS or NEMS) were assessed for 6126 consecutive admissions (23910 ICU-days) at three intensive care units. Inter-rater reliability was analyzed by having nurses at nine ICUs score workload using NCR11 for three dummy intensive care patient cases presented over a 3-year period. Variability in scoring was analyzed using the coefficient of variation. RESULTS: Agreement between NCR11 and TISS or NEMS was poor and limits of agreement were wide. Linear relationships between NCR11 and TISS or NEMS scores differed between units. Variability in NCR11 scoring decreased significantly from 10.4% to 5.9% between dummy cases 1 and 2 and remained low for patient case 3. CONCLUSION: The NCR11 does not measure the same elements of workload in the ICU as do TISS and NEMS. Inter-rater reliability with NCR11 is good, showing little variation in scoring between nurses.     

An evaluation of inpatient morbidity and critical care provision in Zambia

The aim of this study was to objectively measure demand for critical care services in a southern African tertiary referral centre. We carried out a point prevalence study of medical and surgical admissions over a 48‐h period at the University Teaching Hospital, Lusaka, recording the following: age; sex; diagnosis; Human Immunodeficiency Virus (HIV) status and National Early Warning Score. One‐hundred and twenty medical and surgical admissions were studied. Fifty‐four patients (45%) had objective evidence of a requirement for critical care review and potential or probable admission to an intensive care unit, according to the Royal College of Physicians (UK) guidelines. A greater than expected HIV rate was also noted; 53 of 75 tested patients (71%). When applied to the estimated 17,496 annual acute admissions, this would equate to 7873 patients requiring critical care input annually at this hospital alone. In contrast to this demand, we identified 109 critical care beds nationally, and only eight at this institution.     

Factors predicting discharge from intensive care: A Canadian experience

This study prospectively analyzed 481 admissions to a multidisciplinary intensive care unit in order to determine factors which may prove helpful in predicting outcome from an intensive care admission. Severity of illness was assessed by the admission acute physiology score and daily therapeutic intervention scoring system. Age, sex, diagnosis upon admission, nature of the admission (medical vs. surgical, emergency vs. elective) were also studied. Our results indicate that the admission acute physiology score during the first three days of the admission and thereafter, the daily therapeutic intervention scores from the previous day are the most reliable predictors of outcome from intensive care. Age was related to outcome only when it was associated with emergency and medical type admissions. A linear logistic regression analysis was used to construct a model predicting mortality within the intensive care unit based on acute physiology score and nature of the admission.     

A generic simulation model for planning critical care resource requirements

Intensive care capacity planning based on factual or forecasted mean admission numbers and mean length of stay without taking non‐linearity and variability into account is fraught with error. Simulation modelling may allow for a more accurate assessment of capacity needs. We developed a generic intensive care simulation model using data generated from anonymised patient records of all admissions to four different hospital intensive care units. The model was modified and calibrated stepwise to identify important parameters and their values to obtain a match between model predictions and actual data. The most important characteristic of the final model was the dependency of admission rate on actual occupancy. Occupancy, coverage and transfers of the final model were found to be within 2% of the actual data for all four simulated intensive care units. We have shown that this model could provide accurate decision support for planning critical care resource requirements.     

Optimizing physician staffing and resource allocation: sine-wave variation in hourly trauma admission volume

BACKGROUND: Trauma centers are faced with the challenge of managing an increasing volume of patients in an era of fewer trauma care providers and fewer hospitals providing trauma care. The purpose of this study was to determine the relationship between hourly admission volume, injury severity, resource utilization, and outcomes. METHODS: All patients in the National Trauma Data Bank admitted between 1999 and 2002 were selected. Analysis included demographics, temporal information, injury severity, and outcome parameters. RESULTS: A total of 421,997 patients were admitted to participating centers. The 24-hour admission distribution described a sine-wave pattern with a trough at 6:00 am and a peak at 7:00 pm. The sine-wave pattern persisted regardless of the subgroup analyzed. Patients admitted between 12:00 am and 6:00 am were more likely to be severely injured, require intensive care unit admission, undergo emergent operation, and die during hospitalization when compared with patients admitted between 7:00 am and 12:00 pm. CONCLUSIONS: Trauma admissions conform to a sine-wave pattern with a 3.5-fold increase in admissions between morning and evening hours. This has significant implications for manpower and resource allocation with additional resources needed in the hours around 7:00 pm and later. Educational and administrative activities are best scheduled during low-volume morning hours. Nighttime admissions are higher risk and thus more likely to need senior-level expertise and consume hospital resources. Trauma centers should use these findings to improve outcomes by developing optimal staffing patterns and matching resource allocation to need as a function of time.     

Intensive care use by critically ill obstetric patients: a five-year review

This is a retrospective analysis of all obstetric admissions to the surgical intensive care unit over the five-year period beginning July 1, 1994. The admission diagnosis, mode of delivery, anaesthetic employed and patient outcome were assessed. There were 43 obstetric admissions during this period, with 38 deliveries. This represents 0.32% of the deliveries in this hospital during the study period. The median duration of stay was three days (range 1-21). Haemorrhage and pregnancy-induced hypertension accounted for the majority of obstetric complications. Anaesthesia may have contributed to the admission of eight patients. Eight patients had more than one admission diagnosis. There were two deaths and one case of major morbidity (hypoxic encephalopathy) in this series. Prolonged ventilation and/or inotropic support were generally not required. In conclusion, approximately 3 per 1000 maternities require intensive care in this institution. The majority are discharged after a short stay with good outcome.     

Unplanned anesthesia-related admissions to pediatric intensive care - a 6-year audit

BACKGROUND: Unplanned admissions to the intensive care unit may result from unexpected events related to anesthesia, and are recommended by some healthcare organizations as a clinical indicator. The rate of anesthesia-related unplanned admissions in adults ranges between 0.04% and 0.45% of procedures. However, there is a paucity of data relating to the rate in children. METHODS: Admissions to the pediatric intensive care unit (PICU) occurring within 24 h of anesthesia were identified through retrospective chart review. Only those admissions from a complication of anesthesia were included and not those from communication errors or surgical problems. The aim was to determine the rate of unplanned admissions, as well as the causes and management of this group of unplanned admissions. RESULTS: Seventy-six children requiring admission to the PICU were identified from 55196 procedures during the 6-year study period. The rate of unplanned admission was 0.14% of procedures. A total of 47% of these admissions were related to airway problems and 68% of children requiring admission were aged less than 5 years. Most children required only observation after their admission. CONCLUSIONS: We found the unplanned admission rate to the PICU in our hospital population to be similar to that reported for adults, and is a relatively rare event in pediatric anesthesia. Most admissions were for children aged less than 5 years and were as a result of airway problems. Most cases were deemed potentially predictable.     

Hyperglycaemic emergency admissions to a secondary-level hospital - an unnecessary financial burden.

BACKGROUND AND OBJECTIVES: Diabetes affects approximately 1 million South Africans. Hospital admissions, the largest single item of diabetes expenditure, are often precipitated by hyperglycaemic emergencies. A recent survey of a 200- bed hospital, serving approximately 1.3 million Cape Town residents, showed that hyperglycaemic emergencies comprised 25.6% of high-care unit admissions. A study was undertaken to determine the reasons for, and financial cost of, these admissions. METHODS: All hyperglycaemic admissions during a 2-month period (1 September - 31 October 2005) were surveyed prospectively. Admissions were classified using the American Diabetes Association classification of hyperglycaemic emergencies. Demographic data, and the reason for, duration of and primary outcome of admission, were recorded. The following costs per admission were calculated using publicsector pricing: (i) total costs; (ii) patient-specific costs; (iii) nonpatient- specific costs; and (iv) capital costs. RESULTS: Sepsis (36%), non-compliance with therapy (32%) and a new diagnosis of diabetes (11%) were the predominant reasons for admission of 53 hyperglycaemic emergency cases. Mean duration of hospital stay was 4 days, with an in-hospital mortality of 7.5%. Mean cost per admission was R5 309. Clinical staff (25.8%), capital (25.6%) and overhead (34%) costs comprised 85.4% of expenditure. DISCUSSION AND RECOMMENDATIONS: Hyperglycaemic admissions, costing more than R5 300 per patient, represent a health burden that has remained unchanged over the past 20 years. Urgently required primary care preventive strategies include early diagnosis of diabetes, timely identification and treatment of precipitating causes, specifically sepsis, and education to improve compliance.     

Physiological values and procedures in the 24 h before ICU admission from the ward

Physiological values and interventions in the 24 h before entry to intensive care were collected for admissions from hospital wards. In a 13-month period, there were 79 admissions in 76 patients who had been in hospital for at least 24 h and had not undergone surgery within 24 h of admission to intensive care. Thirty-four per cent of patients underwent cardiopulmonary resuscitation before intensive care admission. Using Acute Physiology and Chronic Health Evaluation II scoring to quantify abnormal physiology in the group as a whole, a significant deterioration in respiratory function before admission was found. During the 6-h period immediately before intensive care admission, 75% of patients received oxygen, 37% underwent arterial blood gas sampling, and oxygen saturation was measured in 61% of patients, 63% of whom had an oxygen saturation of less than 90%. Overall hospital mortality in the study group was 58%. Information collected on the wards identified seriously ill patients who may have benefited from earlier expert treatment.     

Immediate and 5-year cumulative outcome after paediatric intensive care in Sweden

Background: Little has been reported about intensive care of children in Sweden. The aims of this study are to (I) assess the number of admissions, types of diagnoses and length-of-stay (LOS) for all Swedish children admitted to intensive care during the years 1998–2001, and compare paediatric intensive care units (PICUs) with other intensive care units (adult ICUs) (II) assess immediate (ICU) and cumulative 5-year mortality and (III) determine the actual consumption of paediatric intensive care for the defined age group in Sweden.
Methods: Children between 6 months and 16 years of age admitted to intensive care in Sweden were included in a national multicentre, ambidirectional cohort study. In PICUs, data were also collected for infants aged 1–6 months. Survival data were retrieved from the National Files of Registration, 5 years after admission.
Results: Eight-thousand sixty-three admissions for a total of 6661 patients were identified, corresponding to an admission rate of 1.59/1000 children per year. Median LOS was 1 day. ICU mortality was 2.1% and cumulative 5-year mortality rate was 5.6%. Forty-four per cent of all admissions were to a PICU.
Conclusions: This study has shown that Sweden has a low immediate ICU mortality, similar in adult ICU and PICU. Patients discharged alive from an ICU had a 20-fold increased mortality risk, compared with a control cohort for the 5-year period. Less than half of the paediatric patients admitted for intensive care in Sweden were cared for in a PICU. Studies are needed to evaluate whether a centralization of paediatric intensive care in Sweden would be beneficial to the paediatric population.     

Queuing theory accurately models the need for critical care resources

BACKGROUND: Allocation of scarce resources presents an increasing challenge to hospital administrators and health policy makers. Intensive care units can present bottlenecks within busy hospitals, but their expansion is costly and difficult to gauge. Although mathematical tools have been suggested for determining the proper number of intensive care beds necessary to serve a given demand, the performance of such models has not been prospectively evaluated over significant periods. METHODS: The authors prospectively collected 2 years' admission, discharge, and turn-away data in a busy, urban intensive care unit. Using queuing theory, they then constructed a mathematical model of patient flow, compared predictions from the model to observed performance of the unit, and explored the sensitivity of the model to changes in unit size. RESULTS: The queuing model proved to be very accurate, with predicted admission turn-away rates correlating highly with those actually observed (correlation coefficient = 0.89). The model was useful in predicting both monthly responsiveness to changing demand (mean monthly difference between observed and predicted values, 0.4+/-2.3%; range, 0-13%) and the overall 2-yr turn-away rate for the unit (21%vs. 22%). Both in practice and in simulation, turn-away rates increased exponentially when utilization exceeded 80-85%. Sensitivity analysis using the model revealed rapid and severe degradation of system performance with even the small changes in bed availability that might result from sudden staffing shortages or admission of patients with very long stays. CONCLUSIONS: The stochastic nature of patient flow may falsely lead health planners to underestimate resource needs in busy intensive care units. Although the nature of arrivals for intensive care deserves further study, when demand is random, queuing theory provides an accurate means of determining the appropriate supply of beds.     

Maternal and neonatal characteristics in obstetric intensive care unit admissions

BackgroundThe objective of this study was to evaluate the course of pregnancy and delivery of obstetric patients admitted for intensive care, and determine the health status of their infants.MethodsThis was a retrospective register-based study. Four university hospitals in Finland participated. Obstetric patients admitted to the intensive care unit in any trimester of pregnancy, during delivery or up to 42 days post partum were identified from clinical information systems over a five-year study period. Parturient and infant data were collected from the Medical Birth Register.ResultsDuring the study period (2007–2011), 283 obstetric patients were identified from the clinical information system. The most common reason for admission was hypertensive complications (58%), followed by obstetric haemorrhage (25.1%). Advanced maternal age, nulliparity and multiple pregnancies were associated with obstetric intensive care unit admissions. Of patients admitted to intensive care, 68.9% delivered by unscheduled caesarean section. Nearly 60% of neonates were born preterm, 56.1% needed treatment in a neonatal intensive care unit or an observation unit and 4.6% died within one week.ConclusionAdvanced maternal age, nulliparity and multiple pregnancy were more common among intensive care unit-admitted women than in the general obstetric population. The main causes for admission were hypertensive complications and obstetric haemorrhage. Compared with the general obstetric population, neonates of intensive care unit-admitted mothers were eight times more likely to require treatment on a neonatal ward and their risk of neonatal death was also eight times greater.     

Intensive care utilization during hospital admission for delivery: prevalence, risk factors, and outcomes in a statewide population

BACKGROUND: During childbirth, the maternal need for intensive care unit (ICU) services is not well-defined. This information could influence the decision whether to incorporate ICU services into the labor and delivery suite. METHODS: This study reports (1) ICU use and mortality rates in a statewide population of obstetric patients during their hospital admission for childbirth, and (2) the risk factors associated with ICU admission and mortality. A case-control design using patient records from a state-maintained anonymous database for the years 1984-1997 was used. Outcome variables included ICU use and mortality rates. RESULTS: Of the 822,591 hospital admissions for delivery of neonates during the study period, there were 1,023 ICU admissions (0.12%) and 34 ICU deaths (3.3%). Age, race, hospital type, volume of deliveries, and source of admission independently and in combination were associated with ICU admission (P < 0.05). The most common risk factors associated with ICU admission included cesarean section, preeclampsia or eclampsia, and postpartum hemorrhage (P < 0.001). Black race, high hospital volume of deliveries, and longer duration of ICU stay were associated with ICU mortality (P < 0.05). The most common risk factors associated with ICU mortality included pulmonary complications, shock, cerebrovascular event, and drug dependence (P < 0.05). CONCLUSIONS: This study shows that ICU use and mortality rate during hospital admission for delivery of a neonate is low. These results may influence the location of perinatal ICU services in the hospital setting.     

Intensive Care Utilization during Hospital Admission for Delivery : Prevalence, Risk Factors, and Outcomes in a Statewide Population

Background: During childbirth, the maternal need for intensive care unit (ICU) services is not well-defined. This information could influence the decision whether to incorporate ICU services into the labor and delivery suite.

Methods: This study reports (1) ICU use and mortality rates in a statewide population of obstetric patients during their hospital admission for childbirth, and (2) the risk factors associated with ICU admission and mortality. A case-control design using patient records from a state-maintained anonymous database for the years 1984-1997 was used. Outcome variables included ICU use and mortality rates.

Results: Of the 822,591 hospital admissions for delivery of neonates during the study period, there were 1,023 ICU admissions (0.12%) and 34 ICU deaths (3.3%). Age, race, hospital type, volume of deliveries, and source of admission independently and in combination were associated with ICU admission (P < 0.05). The most common risk factors associated with ICU admission included cesarean section, preeclampsia or eclampsia, and postpartum hemorrhage (P < 0.001). Black race, high hospital volume of deliveries, and longer duration of ICU stay were associated with ICU mortality (P < 0.05). The most common risk factors associated with ICU mortality included pulmonary complications, shock, cerebrovascular event, and drug dependence (P < 0.05).