Medication errors in residential facilities based on Danish Poison Information Center inquiries

INTRODUCTION

This study describes the types and health consequences of medication errors in residential facilities for which the Danish Poison Information Center (DPIC) was contacted.

METHODS

This study is based on all inquiries made by residential facilities to the DPIC during a 13-month period. Information about inquirers and residents, data related to the medication error, symptoms, risk assessments and recommendations was collected, and a follow-up phone call was made to evaluate the clinical outcomes, preferably within one week.

RESULTS

During the study period, the DPIC received 146 inquiries concerning medication errors in residential facilities. Nearly all inquiries concerned excess administration of medication (96%) and often involved medications targeting the nervous system (65%). In 9% of cases, the DPIC recommended hospitalisation. Most medication errors (92%) were considered of "no or minor risk". Administration of medication to the wrong resident is a frequent reason for consulting the DPIC (45%) in cases with medication errors.

CONCLUSIONS

In this study, we inventoried the inquiries made to the DPIC about medication errors in residential facilities in Denmark. Most medication errors did not carry a risk of serious health consequences, but continued monitoring is warranted to minimise risk in this vulnerable population.

FUNDING

Copenhagen Center for Health Technology (5001105002), Department of Clinical Pharmacology (Bispebjerg Hospital, The Capital Region) (1152871001).

TRIAL REGISTRATION

not relevant.

A poison information centre can provide important assessment and guidance regarding medication errors in nursing homes: A prospective cohort study

The Danish Poison Information Centre (DPIC) regularly receives inquiries about nursing home residents who have been exposed to a medication error. The aim of this prospective cohort study was to describe and discuss the types and consequences of these errors. Data were collected from 1 March 2018 to 31 March 2019. Registered data included characteristics of caller and resident, data related to the suspected medication error, risk assessment and recommendation. Consequences and clinical outcomes were assessed by follow-up telephone calls. Over the study period, the DPIC was consulted about 145 medication errors occurring at Danish nursing homes. The median number of substances administered by error was two (interquartile range 1-5). Hospitalization was recommended in 21% of cases. In one-third of the cases where consultation with the DPIC was done with the resident either on his/her way to or in hospital, hospitalization was found unnecessary, and the resident could have stayed in accustomed surroundings for observation. Follow-up demonstrated that very few medication errors had a severe outcome. This prospective study illustrates that consulting with a poison information centre can qualify risk assessment and potentially reduce hospital admissions following medication errors in a nursing home setting.

Patient-focused research: using patient outcome data to enhance treatment effects

A program of research aimed at improving the quality of psychological interventions is described. Data from over 10,000 patients were analyzed to understand the association between number of treatment sessions and clinically significant improvement. In addition to a potential dose-response relationship, typical recovery curves were generated for patients at varying levels of disturbance and were used to identify patients whose progress was less than expected ("signal" cases). The consequences of passing this information along to therapists were reported. Analyses of dose-response data showed that 50% of patients required 21 sessions of treatment before they met criteria for clinically significant improvement. Seventy-five percent of patients were predicted to improve only after receiving more than 40 treatment sessions in conjunction with other routine contacts, including medication in some cases. Identification of signal cases (potential treatment failures) shows promise as a decision support tool, although further research is needed to elucidate the nature of helpful feedback. Outgrowths of this research include its possible contribution to social policy decisions, reductions in the need for case management, use in supervision, and possible effects on theories of change.

Prognostic significance of cystic intracranial lesions in neonates

Thirty-five infants with cystic parenchymal lesions detected by ultrasonography during the neonatal period were evaluated via periodic neurologic and developmental assessments. Long-term neurologic status (abnormal, normal, and isolated motor deficit) was assigned at 2 years of age. Abnormal neurologic status was strongly associated with bilateral cystic lesions as well as hydrocephalus during the neonatal period. Microcephaly at 6-8 months of age also correlated with abnormal status at 2 years of age. The neurologic exam at discharge and at 6-8 months of age added further negative predictive value for the infants with isolated motor delays. A literature review was conducted to determine the incidence of motor and mental delays in a large series of infants with cystic intracranial lesions.

Intestinal blood flow and oxygen uptake in the neonatal piglet during reduced perfusion pressure

The effect of reduced perfusion pressure on neonatal intestinal blood flow, vascular resistance, arterio-venous oxygen content (a-v O2), and oxygen uptake was studied in nine fasted newborn piglets, aged 5-6 days. Successive reductions of intestinal perfusion pressure were achieved by a clamp on the thoracic aorta. Intestinal blood flow decreased after each reduction of perfusion pressure. Intestinal vascular resistance increased and Gf, a measure of flow control, was negative after all but the final, most severe reduction of perfusion pressure. However, intestinal a-v O2 increased after each pressure reduction and intestinal oxygen uptake was thus maintained at greater than or equal to 95% of its baseline value until perfusion pressure was reduced to less than or equal to 70% of its base-line value. The neonatal intestine maintains tissue oxygen uptake during moderate hypotension, and this is accomplished by regulation of a-v O2, rather than by regulation of blood flow.

The effect of naloxone on the hemodynamics of the newborn piglet with septic shock

Naloxone has been shown to reverse the hemodynamic sequelae of experimental septic shock in adult animal models. Its effectiveness in the newborn has not been studied. To further investigate the efficacy of naloxone, we instrumented 18 piglets for continuous measurement of mean arterial pressure, mean pulmonary arterial pressure, central venous pressure, heart rate, left ventricular pressure, contractility, cardiac output, and O2. Oxygen consumption, systemic vascular resistance, and pulmonary vascular resistance were calculated. Following a stabilization period, group B beta-hemolytic Streptococci were infused over 30 min. Following the infusion, naloxone (1 mg/kg) was given followed by a continuous infusion of 1 mg/kg/h in nine treatment animals. Nine control animals were given an equal volume of saline. Both groups developed significant increases in mean pulmonary arterial pressure followed by a return to baseline. Oxygen consumption, cardiac output, contractility and mean arterial pressure decreased in both groups. Treatment with naloxone was associated with a cessation in the fall in the mean arterial pressure and the contractility. The difference in mean arterial pressure and contractility between groups was significant. The naloxone group had significantly improved 5-h survival. We speculate that naloxone may reverse some of the hemodynamic sequelae and improve survival in newborns with septic shock.

Intestinal blood flow and O2 uptake during hypoxemia in the newborn piglet

Previous work has indicated that the neonatal intestinal circulation responds to hypoxemia with vasoconstriction and subsequent intestinal ischemia. This work was carried out in newborn lambs, a ruminant species, and may not be representative of all newborns. Therefore, we measured intestinal blood flow, vascular resistance, tissue O2 uptake, and cardiac output during normoxemia and varying degrees of hypoxemia in newborn piglets, a nonruminant species. Hypoxemia was induced by adding N2 gas to the inspired gas mixture, and measurements were obtained over a wide range of arterial O2 contents (2.2-15.6 ml O2 X dl-1). Intestinal blood flow increased in response to moderate hypoxemia and decreased in response to severe hypoxemia. The changes in intestinal blood flow were primarily due to change in intestinal vascular resistance, not cardiac output. Intestinal O2 was independent of arterial O2 content until the latter decreased below approximately 6.5 ml O2 X dl-1. These data indicate that the response of the neonatal intestinal circulation to hypoxemia is species specific and that the nonruminant neonatal intestine is capable of vasodilation in response to moderate hypoxemia.

Budd-Chiari syndrome in a premature infant receiving total parenteral nutrition

A premature infant who developed Budd-Chiari syndrome as a complication of total parenteral nutrition through an inferior vena cava catheter is presented. A novel approach to the treatment of this otherwise lethal condition is described. This very unusual complication in pediatric patients may be seen with increased frequency as more premature infants are treated with central vein total parenteral nutrition.

Alterations in cerebral blood flow and oxygen consumption during prolonged hypocarbia

The effect of prolonged (2 h) hypocarbia on cerebral blood flow, oxygen delivery, extraction, and consumption was studied in eight, 1- to 4-day-old piglets. Hyperventilation to PaCO2 less than 20 mm Hg acutely (30 min) decreased cerebral blood flow and oxygen consumption. Cerebral oxygen consumption was subsequently restored via increases in cerebral blood flow and thus, cerebral oxygen delivery. Cerebral oxygen extraction rose from a normocarbic baseline of 50 to 75% with acute hypocarbia and was maintained at this level. The percent decrease in blood flow to the cerebrum was greater than that to other brain regions during hypocarbia.

Gastrointestinal blood flow and O2 uptake in piglets: recovery from hypoxemia

Gastrointestinal (GI) blood flow, O2 transport, and O2 uptake were measured during recovery from severe hypoxemia in newborn piglets. Hypoxemia was induced by lowering the inspired O2 concentration to 0.05 for 15 min. This resulted in an 82% decrease in GI O2 uptake. Recovery measurements were obtained 5 and 65 min after restoration of normoxia. During early recovery (5 min), GI O2 uptake increased above prehypoxemia baseline, presumably to "repay" the O2 deficit incurred during hypoxemia. This was mediated by an increase in the arteriovenous O2 content difference, as GI blood flow did not increase above prehypoxemia baseline. During late recovery (65 min), GI blood flow, O2 delivery, and arteriovenous O2 content difference decreased below prehypoxemia baseline. This resulted in a 52% decrease in GI O2 uptake below prehypoxemia baseline. Therefore, early recovery was characterized by an appropriate increase in GI O2 uptake; however, late recovery was characterized by a significant reduction in GI O2 transport and uptake. Circulatory homeostasis was not reestablished during the late recovery period.

The effect of blood volume expansion on gastrointestinal oxygenation in piglets

Regional and total gastrointestinal (GI) blood flow, O2 delivery, O2 extraction, and O2 consumption were measured before and after acute blood volume expansion in 2-day-old piglets. Blood flow was measured with radionuclide-labeled microspheres. Sixty minutes after a rapid transfusion of age- and hematocrit-matched piglet donor blood, 51Cr-measured blood volume increased 19% while an increase in hematocrit suggested plasma transudation to the extravascular space had occurred in response to blood volume loading. Following transfusion, total GI blood flow and O2 delivery did not change, although O2 extraction decreased by 31 +/- 4%. O2 consumption by the GI tract decreased from 2.0 +/- 0.19 ml O2 X min-1 X 100 g-1 to 1.46 +/- 0.24 ml O2 X min-1 X 100 g-1 1 h after transfusion. Feeding was then accomplished via orogastric tube to determine if animals stressed by blood volume loading would increase GI O2 consumption in response to feeding. The postprandial increase in GI O2 consumption was similar to that previously reported in newborn piglets. Therefore, in the fasting state, acute blood volume loading disrupts GI O2 transport at the capillary level and decreases GI O2 consumption. However, animals subjected to blood volume loading appear capable of increasing GI O2 consumption after feeding.

The effects of variations in PaCO2 on brain blood flow and cardiac output in the newborn piglet

The acute effects of normoxemic hypocarbia and hypercarbia were examined in six newborn piglets. Brain blood flow was maintained during hypocarbia until extremely low PaCO2 (less than 15 mm Hg) levels were achieved at which time total brain and cerebral blood flow decreased significantly from baseline values. Blood flow to the thalamus, cerebellum and brain stem was unchanged from baseline conditions during hypocarbia. This suggests that the newborn brain is relatively insensitive to moderate degrees of hypocarbia. Extreme hypocarbia (PaCO2 less than 15 mm Hg) was associated with a significant increase in heart rate, accompanied by a significant decrease in mean arterial blood pressure; however, cardiac output was not significantly different from baseline determinations. Hypercarbia with normoxemia was associated with significant increases in total brain blood flow, with greater blood flow to the brain stem, cerebellum, and thalamus than to the cerebrum. The percentage of cardiac output received by the brain was also significantly increased, although total cardiac output was unchanged. This demonstrates that the newborn cerebral vasculature is sensitive to hypercarbia and that regional differences in sensitivity may account for the greater increments in blood flow to the caudal portions of the brain than that to the cerebrum.

Effect of polycythemia on gastrointestinal blood flow and oxygenation in piglets

Gastrointestinal blood flow and oxygenation were measured before and after the induction of polycythemia in newborn piglets. Sixty minutes after exchange transfusion with age-matched packed red blood cells, hematocrit and in vitro whole blood viscosity increased, while 51Cr-measured blood volume did not change. Cardiac output and total gastrointestinal blood flow (the sum of stomach, jejunum, ileum, and colon blood flows) decreased a similar degree after exchange transfusion, although the reduction in total gastrointestinal blood flow was not uniform in all regions of the gastrointestinal tract. Specifically, blood flow to the stomach and mucosa-submucosa layer of the small bowel decreased, whereas that to the colon and muscularis-serosa layer of the small bowel remained unchanged. Gastrointestinal O2 delivery increased after exchange transfusion because of the increase in arterial O2 content consequent to polycythemia. The arteriovenous O2 content difference remained unchanged following exchange transfusion, and gastrointestinal O2 consumption thus decreased 49 +/- 2%. After a test meal, postprandial values for gastrointestinal blood flow and oxygenation in polycythemic piglets increased to levels similar to postprandial values reported previously in normal newborn piglets.

Gastrointestinal blood flow and oxygen consumption in the newborn lamb: effect of chronic anemia and acute hypoxia

The purpose of this study was to investigate the compensatory change in circulation and oxygenation of the newborn lamb gastrointestinal (GI) tract in response to anemic and hypoxic hypoxemia. Radiolabeled microspheres were used to measure blood flow. We subjected the newborn lamb to a 30-35% reduction in hematocrit 4 d before study and to a 10% oxygen environment for 30 min during the study to induce chronic anemic and acute hypoxic hypoxemia, respectively. The circulatory and oxygenation responses were measured 1 h after a standard milk feeding in all cases. During the experimental periods, no change in total GI blood flow was observed. Because of a failure to augment blood flow during hypoxemia, O2 delivery to the GI tract decreased significantly. Despite this, GI O2 consumption was not compromised because tissue O2 extraction by the GI tract rose significantly. The response of the newborn lamb GI tract to hypoxemia after feeding is augmentation of O2 extraction. The newborn's GI tract did not regulate local GI blood flow.

Cerebral blood flow in the newborn lamb with polycythemia and hyperviscosity

We measured hematocrit, whole blood viscosity, arterial oxygen content, and cerebral blood flow in seven newborn lambs in which polycythemia and hyperviscosity were induced by partial exchange transfusion with packed red blood cells from a donor lamb. After the exchange transfusion, the hematocrit, whole blood viscosity, and arterial oxygen content were significantly elevated, whereas cerebral blood flow was reduced from baseline measurements. Sodium nitrite was then infused to reduce the arterial oxygen content to baseline values while the hematocrit and viscosity remained elevated. Under this condition, cerebral blood flow returned to baseline values. Oxygen delivery to the brain remained constant throughout the study. These results indicate that the reduction of cerebral blood flow in neonatal polycythemia and hyperviscosity is a physiologic response to increased arterial oxygen content and not a result of hyperviscosity.

Effects of maternal ritodrine administration on neonatal renal function

Because of its effects on the cardiovascular and renin-angiotensin systems and on fluid and electrolyte homeostasis, maternal administration of ritodrine to inhibit preterm labor may cause significant alterations in renal function in the newborn infant. We determined inulin clearance, plasma renin activity, urinary arginine vasopressin excretion, and serum and urine electrolyte concentrations and osmolalities at 12 to 36 hours of life and at 6 days of life in 15 infants whose mothers had received ritodrine and in 15 infants whose mothers did not (control infants). At the time of each study, plasma ritodrine concentrations were obtained in the infants whose mothers received ritodrine. The infants whose mothers had received ritodrine had significantly lower inulin clearances and higher plasma renin activity and urinary arginine vasopressin excretion on day 1 but not on day 6. Gestational age was inversely correlated with plasma ritodrine concentration, plasma renin activity, and urinary arginine vasopressin excretion. There were no overt clinical signs of renal failure in any of the infants, and no differences in serum and urine electrolyte values, osmolality, fractional sodium excretion, or urine flow rate were observed between the groups.

Gastrointestinal blood flow and oxygen consumption in awake newborn piglets: effect of feeding

Regional and total gastrointestinal (GI) blood flow, O2 delivery, and whole-gut O2 extraction and O2 consumption were measured before and 30, 60, and 120 min after feeding in nonanesthetized, awake 2-day-old piglets. Cardiac output and blood flow to kidneys, heart, brain, and liver were also determined. Blood flow was measured using the radiolabeled microsphere technique. In the preprandial condition, total GI blood flow was 106 +/- 9 ml X min-1 X 100 g-1, while O2 extraction was 17.2 +/- 0.9% and O2 consumption was 1.99 +/- 0.19 ml O2 X min-1 X 100 g-1. Thirty minutes after slow gavage feeding with 30 ml/kg artificial pig milk, O2 delivery to the GI tract and O2 extraction rose significantly (P less than 0.05) by 35 +/- 2 and 33 +/- 2%, respectively. The increase in O2 delivery was effected by a significant increase in GI blood flow, which was localized to the mucosal-submucosal layer of the small intestine. O2 uptake by the GI tract increased 72 +/- 4% 30 min after feeding. Cardiac output and blood flow to non-GI organs did not change significantly with feeding, whereas arterial hepatic blood flow decreased significantly 60 and 120 min after feeding. The piglet GI tract thus meets the oxidative demands of digestion and absorption by increasing local blood flow and tissue O2 extraction.

Glucocorticoid accelerates renal functional maturation in fetal lambs

Renal function was measured in seven premature lambs delivered spontaneously after a fetal injection of betamethasone, four near term lambs delivered via cesarean section after a fetal injection of a placebo and in ten spontaneously delivered full term lambs. Glomerular filtration rates were significantly higher in the premature betamethasone treated than in the near term placebo treated and the full term lambs. Fractional sodium excretions were significantly lower in the betamethasone treated preterm than the placebo treated near term lambs. This suggests that glucocorticoid accelerates renal glomerular and possibly tubular maturation. As in the lung, fetal administration of glucocorticoid stimulates functional maturation of the kidney.

Validity of Doppler measurements of anterior cerebral artery blood flow velocity: correlation with brain blood flow in piglets

Continuous wave Doppler ultrasonography through the anterior fontanel has recently been used to assess changes in cerebral blood flow in human neonates. There has been controversy concerning whether measurements of Doppler blood flow velocity indeed correlate with brain blood flow. An in vivo correlation was performed between brain blood flow as measured by the microsphere method and Doppler flow velocity measurements of the cerebral arteries via an artificial fontanel in young piglets. The peak systolic velocity (r = .76, P less than .001), end diastolic velocity (r = .72, P less than .001) and area under the velocity curve (r = .86, P less than .001) all showed significant positive correlations with brain blood flow. The pulsatility index did not correlate with brain blood flow. Although continuous wave Doppler flow velocity measurements of the anterior cerebral artery cannot quantitatively assess cerebral blood flow, this methodology can be used to correlate changes in cerebral blood flow and provide a meaningful trend analysis following physiologic or pharmacologic perturbation of the cerebral circulation.

Effect of aminophylline on brain blood flow in the newborn piglet

The effect of 6 mg/kg of aminophylline on brain blood flow was examined in newborn piglets. Arterial plasma aminophylline concentration averaged 7 mg/l. Total brain, regional brain (cerebrum, cerebellum and stem) and eye blood flow as well as the total brain oxygen consumption were not altered by aminophylline treatment. Choroid plexus blood flow was five times higher than the total brain blood flow in these newborn piglets. In contrast to brain blood flow, choroid plexus blood flow decreased significantly following aminophylline administration.