The Beers criteria: Not just for geriatrics anymore? Analysis of Beers criteria medications in nongeriatric trauma patients and their association with falls.

BACKGROUND: It has been well established that many classes of medications on the Beers list of Potentially Inappropriate Medications (PIMs) are associated with falls and injuries in the geriatric population, but little work has been performed to understand if similar relationships exist among the nongeriatric adult population. METHODS: A retrospective chart review of 32 months of trauma encounters at our Level I trauma center was performed in nongeriatric adults aged 18 years to 64 years. Encounters were reviewed by mechanism of injury and intake medication reconciliation. The data were then evaluated for associations between PIMs and falls. RESULTS: Of the 7,897 trauma encounters in the study period, 6,493 had completed medication reconciliation, and 4,154 were between the ages of 18 years and 64 years. There was a statistically significant disproportionate number of those who sustained a fall on psychoactive medications and proton pump inhibitors, and the odds of a trauma patient presenting as a fall were also significantly higher on these select classes of PIMs. CONCLUSION: The PIMs associated with falls in the geriatric population are also associated with falls in the nongeriatric population. This study supports the judicious prescribing of these medications, as they may have risks beyond what was originally thought. LEVEL OF EVIDENCE: Prognostic, level IV.

Multiagent neoadjuvant chemotherapy and tumor response are associated with improved survival in pancreatic cancer.

BACKGROUND: Neoadjuvant therapy (NT) for borderline resectable pancreatic cancer (BRPC) has evolved to include multi-agent regimens and chemoradiation. We report our experience and compare outcomes of initially resectable pancreatic cancer (IRPC) vs BRPC receiving NT across two eras of chemotherapy regimens. METHODS: Data were collected retrospectively on pancreaticoduodenectomy patients between January 2008 and October 2015. Outcomes and survival were compared based on patient, laboratory and treatment factors. RESULTS: 195 patients were included and 133 had IRPC and 62 BRPC. IRPC operations were shorter (449 min vs 520 min, p = 0.003), had less blood loss (663 ml vs 954 ml, p = 0.002) and involved fewer vascular resections (29% vs 76%, p = 0.002). The rate of R0 resection was identical (82%, p = 1) and the IRPC group had higher node-positive ratio (19.3% vs 7.2% p < 0.0001). 15 patients received a single agent regimen while 47 received multi-agent regimens with 90% receiving radiation.Survival was similar between BRPC and IRPC (log-rank p = 0.7). Histopathologic response (CAP grade 0 or 1) was not associated with survival (p = 0.13), but completion of ≥4 cycles of multi-agent pre-operative chemotherapy (p = 0.001) and complete response to NT (p = 0.04) were significant predictors of survival. CONCLUSIONS: BRPC patients treated with NT have similar morbidity and survival to their IRPC counterparts. Pathologic response and modern NT are associated with improved survival.

Task- and time-dependent modulation of Ia presynaptic inhibition during fatiguing contractions performed by humans.

Presynaptic modulation of Ia afferents converging onto the motor neuron pool of the extensor carpi radialis (ECR) was compared during contractions (20% of maximal force) sustained to failure as subjects controlled either the angular position of the wrist while supporting an inertial load (position task) or exerted an equivalent force against a rigid restraint (force task). Test Hoffmann (H) reflexes were evoked in the ECR by stimulating the radial nerve above the elbow. Conditioned H reflexes were obtained by stimulating either the median nerve above the elbow or at the wrist (palmar branch) to assess presynaptic inhibition of homonymous (D1 inhibition) and heteronymous Ia afferents (heteronymous Ia facilitation), respectively. The position task was briefer than the force task (P = 0.001), although the maximal voluntary force and electromyograph for ECR declined similarly at failure for both tasks. Changes in the amplitude of the conditioned H reflex were positively correlated between the two conditioning methods (P = 0.02) and differed between the two tasks (P < 0.05). The amplitude of the conditioned H reflex during the position task first increased (129 ± 20.5% of the initial value, P < 0.001) before returning to its initial value (P = 0.22), whereas it increased progressively during the force task to reach 122 ± 17.4% of the initial value at failure (P < 0.001). Moreover, changes in conditioned H reflexes were associated with the time to task failure and force fluctuations. The results suggest a task- and time-dependent modulation of presynaptic inhibition of Ia afferents during fatiguing contractions.

Presynaptic modulation of Ia afferents in young and old adults when performing force and position control.

The present work investigated presynaptic modulation of Ia afferents in the extensor carpi radialis (ECR) when young and old adults exerted a wrist extension force either to support an inertial load (position control) or to achieve an equivalent constant torque against a rigid restraint (force control) at 5, 10, and 15% of the maximal force. H reflexes were evoked in the ECR by stimulating the radial nerve above the elbow. A conditioning stimulus was applied to the median nerve above the elbow to assess presynaptic inhibition of homonymous Ia afferents (D1 inhibition) or at the wrist (palmar branch) to assess the ongoing presynaptic inhibition of heteronymous Ia afferents that converge onto the ECR motor neuron pool (heteronymous Ia facilitation). The young adults had less D1 inhibition and greater heteronymous Ia facilitation during the position task (79 and 132.1%, respectively) compared with the force task (69.1 and 115.1%, respectively, P < 0.05). In contrast, the old adults exhibited no difference between the two tasks for either D1 inhibition ( approximately 72%) or heteronymous Ia facilitation ( approximately 114%). Contraction intensity did not influence the amount of D1 inhibition or heteronymous Ia facilitation for either group of subjects. The amount of antagonist coactivation was similar between tasks for young adults, whereas it was greater in the position task for old adults (P = 0.02). These data indicate that in contrast to young adults, old adults did not modulate presynaptic inhibition of Ia afferents when controlling the position of a compliant load but rather increased coactivation of the antagonist muscle.

Motor unit recruitment in human biceps brachii during sustained voluntary contractions.

The purpose of the study was to examine the influence of the difference between the recruitment threshold of a motor unit and the target force of the sustained contraction on the discharge of the motor unit at recruitment. The discharge characteristics of 53 motor units in biceps brachii were recorded after being recruited during a sustained contraction. Some motor units (n = 22) discharged action potentials tonically after being recruited, whereas others (n = 31) discharged intermittent trains of action potentials. The two groups of motor units were distinguished by the difference between the recruitment threshold of the motor unit and the target force for the sustained contraction: tonic, 5.9 +/- 2.5%; intermittent, 10.7 +/- 2.9%. Discharge rate for the tonic units decreased progressively (13.9 +/- 2.7 to 11.7 +/- 2.6 pulses s(-1); P = 0.04) during the 99 +/- 111 s contraction. Train rate, train duration and average discharge rate for the intermittent motor units did not change across 211 +/- 153 s of intermittent discharge. The initial discharge rate at recruitment during the sustained contraction was lower for the intermittent motor units (11.0 +/- 3.3 pulses s(-1)) than the tonic motor units (13.7 +/- 3.3 pulses s(-1); P = 0.005), and the coefficient of variation for interspike interval was higher for the intermittent motor units (34.6 +/- 12.3%) than the tonic motor units (21.2 +/- 9.4%) at recruitment (P = 0.001) and remained elevated for discharge duration (34.6 +/- 9.2% versus 19.1 +/- 11.7%, P < 0.001). In an additional experiment, 12 motor units were recorded at two different target forces below recruitment threshold (5.7 +/- 1.9% and 10.5 +/- 2.4%). Each motor unit exhibited the two discharge patterns (tonic and intermittent) as observed for the 53 motor units. The results suggest that newly recruited motor units with recruitment thresholds closer to the target force experienced less synaptic noise at the time of recruitment that resulted in them discharging action potentials at more regular and greater rates than motor units with recruitment thresholds further from the target force.