Intra-operative monitoring--many alarms with minor impact.

Alarms are key components of peri-operative monitoring devices, but a high false-alarm rate may lead to desensitisation and neglect. The objective of this study was to quantify the number of alarms and assess the value of these alarms during moderate-risk surgery. For this purpose, we analysed documentation of anaesthesia workstations during 38 surgical procedures. Alarms were classified on technical validity and clinical relevance. The median (IQR [range]) alarm density per procedure was 20.8 (14.5-34.2 [3.7-85.6]) alarms.h⁻¹ (1 alarm every 2.9 min) and increased during induction and emergence of anaesthesia, with up to one alarm per 0.99 min during these periods (p < 0.001). Sixty-four per cent of all alarms were clinically irrelevant, whereas 5% of all alarms required immediate intervention. The positive predictive value of an alarm during induction and emergence was 20% (95% CI 16-24%) and 11% (95% CI 8-14%), respectively. This study shows that peri-operative alarms are frequently irrelevant, with a low predictive value for an emerging event requiring clinical intervention.

Effects of physician-based emergency medical service dispatch in severe traumatic brain injury on prehospital run time.

INTRODUCTION: Prehospital care by physician-based helicopter emergency medical services (P-HEMS) may prolong total prehospital run time. This has raised an issue of debate about the benefits of these services in traumatic brain injury (TBI). We therefore investigated the effects of P-HEMS dispatch on prehospital run time and outcome in severe TBI. METHODS: Prehospital run times of 497 patients with severe TBI who were solely treated by a paramedic EMS (n = 125) or an EMS/P-HEMS combination (n = 372) were retrospectively analyzed. Other study parameters included the injury severity score (ISS), Glasgow Coma Scale (GCS), prehospital endotracheal intubation and predicted and observed outcome rates. RESULTS: Patients who received P-HEMS care were younger and had higher ISS values than solely EMS-treated patients (10%; P = 0.04). The overall prehospital run time was 74 ± 54 min, with similar out-of-hospital times for EMS and P-HEMS treated patients. Prehospital endotracheal intubation was more frequently performed in the P-HEMS group (88%) than in the EMS group (35%; P<0.001). The prehospital run time for intubated patients was similar for P-HEMS (66 (51-80)min) and EMS-treated patients (59 (41-88 min). Unexpectedly, mortality probability scores and observed outcome scores were less favourable for EMS-treated patients when compared to patients treated by P-HEMS. CONCLUSION: P-HEMS dispatch does not increase prehospital run times in severe TBI, while it assures prehospital intubation of TBI patients by a well-trained physician. Our data however suggest that a subgroup of the most severely injured patients received prehospital care by an EMS, while international guidelines recommend advanced life support by a physician-based EMS in these cases.

Hyperfibrinolysis in out of hospital cardiac arrest is associated with markers of hypoperfusion.

AIM OF THE STUDY: This study investigated the incidence of hyperfibrinolysis upon emergency department (ED) admission in patients with out of hospital cardiac arrest (OHCA), and the association of the degree of hyperfibrinolysis with markers of hypoperfusion. METHODS: From 30 OHCA patients, cardiopulmonary resuscitation (CPR) time, pH, base excess (BE), and serum lactate were measured upon ED admission. A 20% decrease of rotational thromboelastometry maximum clot firmness (MCF) was defined as hyperfibrinolysis. Lysis parameters included maximum lysis (ML), lysis onset time (LOT) and lysis index at 30 and 45 min (LI30/LI45). The study was approved by the Human Subjects Committee. RESULTS: Hyperfibrinolysis was present in 53% of patients. Patients with hyperfibrinolysis had longer median CPR times (36 (15-55) vs. 10 (7-18)min; P=0.001), a prolonged activated partial thromboplastin time (54 ± 16 vs. 38 ± 10s; P=0.006) and elevated D-dimers (6.1 ± 2.1 vs. 2.3 ± 2.0 µg/ml; P=0.02) when compared to patients without hyperfibrinolysis. Hypoperfusion markers, including pH (6.96 ± 0.11 vs. 7.17 ± 0.15; P<0.001), base excess (-20.01 ± 3.53 vs. -11.91 ± 6.44; P<0.001) and lactate (13.1 ± 3.7 vs. 8.0 ± 3.7 mmol/l) were more disturbed in patients with hyperfibrinolysis than in non-hyperfibrinolytic subjects, respectively. The LOT showed a good association with CPR time (r=-0.76; P=0.003) and lactate (r=-0.68; P=0.01), and was longer in survivors (3222 ± 34s) than in non-survivors (1,356 ± 833; P=0.044). CONCLUSION: A substantial part of OHCA patients develop hyperfibrinolysis in association with markers for hypoperfusion. Our data further suggest that the time to the onset of clot lysis may be an important marker for the severity of hyperfibrinolysis and patient outcome.

Prehospital endotracheal intubation in patients with severe traumatic brain injury: guidelines versus reality.

The international Brain Trauma Foundation guidelines recommend prehospital endotracheal intubation in all patients with traumatic brain injury (TBI) and a Glasgow Coma Scale (GCS)< or =8. Close adherence to these guidelines is associated with improved outcome, but not all severely injured TBI patients receive adequate prehospital airway support. Here we hypothesized that guideline adherence varies when skills are involved that rely on training and expertise, such as endotracheal intubation. We retrospectively studied the medical records of CT-confirmed TBI patients with a GCS< or =8 who were referred to a level 1 trauma centre in Amsterdam (n=127). Records were analyzed for demographic parameters, prehospital treatment modalities, involvement of an emergency medical service (EMS) and respiratory and metabolic parameters upon arrival at the hospital. Patients were mostly male, aged 45+/-21 years with a median injury severity score (ISS) of 26. Of all patients for whom guidelines recommend endotracheal intubation, only 56% were intubated. In 21 out of 106 severe cases an EMS was not called for, suggesting low guideline adherence. Especially those TBI patients treated by paramedics tended to develop higher levels of stress markers like glucose and lactate. We observed a low degree of adherence to intubation guidelines in a Dutch urban area. Main reasons for low adherence were the unavailability of specialized care, scoop and run strategies and absence of a specialist physician in cases where intubation was recommended. The discrepancy between guidelines and reality warrants changing practice to improve guideline compliance and optimize outcome in TBI patients.