Improving operating room first start efficiency - value of both checklist and a pre-operative facilitator.

BACKGROUND: There are multiple components leading to improved operating room efficiency. We undertook a project focusing on first case starts; accounting for each delay component on a global basis. Our hypothesis was there would be a reduction in first start delays after we implemented strategies to address the issues identified through this accounting process. METHODS: An orange sheet checklist was implemented, with specific items that needed to be clear prior to roll back to the operating room (OR), and an OR facilitator was employed to intervene whenever there were any missing items needed for a specific patient. We present the data from this quality improvement project over an 18-month period. RESULTS: Initially, 10.07 (± 0.73) delayed first starts occurred per day but declined steadily over time to a low of 4.95 (± 0.38) per day after 6 months (-49.2 %, P < 0.001). By the end of the project, the most common reasons for delay still included late surgical attending (19%), schedule changes (14%) as well as 'other reasons' (13%), but with an overall reduction per day of each. Total anaesthesia delay initially totalled 11% of the first start delays, but was negligible (< 1%) at the project's completion. CONCLUSIONS: While we have a challenging operating room environment based on our patient population, multiple trainees in both the surgery and anaesthesiology teams: an orange sheet - pre-operative checklist in addition to a dedicated pre-operative facilitator; allowed us to make a substantial improvement in our first start on time starts.

Resident training in obstetric anesthesia in the United States.

BACKGROUND: Limited information exists on obstetric anesthesia experience and training within residency training programs in the United States. METHODS: A survey was sent to every academic anesthesiology training program in the United States (n=120), with follow-up reminders to non-responders. The survey included 14 questions divided into staffing, didactic teaching and epidemiology regarding the practice of obstetric anesthesia at each academic institution. RESULTS: A response rate of 78% (93/120) was achieved. The returned surveys were grouped into three tiers by the number of deliveries/year from the lowest (Group 1) to the highest (Group 3). The total number of obstetric deliveries at each institution ranged from 340 to 15 800. The average number of residents/month rotating on obstetric anesthesia was 2.6 and the number of months spent on the obstetric anesthesia service was 2.7. The average number of obstetric anesthesia lectures given was 12 per month. A total of 21.5 obstetric anesthesia fellows were reported to train at these institutions, with fellows being more common in larger institutions. Group 1 institutions were more likely to have anesthesiologists covering the main operating room and obstetric suite simultaneously. The average number of obstetric anesthesia staff members/institution was 4.3. The average cesarean section rate was 27.8%, with 5.8% being performed under general anesthesia. Neuraxial techniques were used in an average of 70.3% of laboring parturients, with combined spinal epidurals accounting for 24.6% of the techniques. CONCLUSION: The average number of obstetric deliveries per year for institutions with a resident training program was 3498+/-2383. Dedicated obstetric anesthesia staffing was more common when >3700 deliveries/year were performed; the presence of this staffing corresponded with a reduction in the use of general anesthesia for cesarean deliveries. Few differences in the resident lecture didactic exposure were observed in terms of numbers of lectures and months on the obstetric anesthesia service, although a significantly greater number of clinical cases was available to each resident in those institutions with greater overall numbers of obstetric cases.

Leukaemia inhibitory factor prevents loss of p75-nerve growth factor receptor immunoreactivity in medial septal neurons following fimbria-fornix lesions.

Transection of the fimbria-fornix leads to retrograde degeneration of axotomized septal cholinergic neurons as manifested by loss of choline acetyltransferase and low-affinity nerve growth factor receptor (p75NGFR) immunoreactivity. Nerve growth factor administered into cerebral ventricles at the time of axotomy can prevent these changes, while ciliary neurotrophic factor can prevent the loss of p75NGFR immunostaining. Leukaemia inhibitory factor shares structural homologies with ciliary neurotrophic factor and has similar actions in the nervous system. Both proteins share the same signalling pathways, which involve the interleukin-6 transducing receptor components leukaemia inhibitory factor receptor beta and gp130. In this study, we compared the effects of leukaemia inhibitory factor, ciliary neurotrophic factor and nerve growth factor, administered into cerebral ventricles, on p75NGFR and choline acetyltransferase immunoreactivity in septal neurons after fimbria-fornix transection. We found that leukaemia inhibitory factor, like ciliary neurotrophic factor, prevents the loss of p75NGFR-stained medial septal neurons after fimbria-fornix axotomy, without maintaining choline acetyltransferase expression in these neurons. In addition, p75NGFR-immunostained neurons had significantly smaller mean diameter after axotomy in leukaemia inhibitory factor- and ciliary neurotrophic factor-treated animals as compared with either nerve growth factor-treated or unlesioned animals. These findings suggest that both leukaemia inhibitory factor and ciliary neurotrophic factor can prevent the axotomy-induced cell death of septal cholinergic neurons, but that, in contrast to nerve growth factor, these growth factors do not maintain the expression of choline acetyltransferase or the normal neuronal size of these injured neurons.

Changes in CCK mRNA in hippocampal neurones following fimbria fornix transection.

Preprocholecystokinin (CCK) mRNA expression was measured in a subset of hippocampal interneurones after transection of afferent septohippocampal fibres in the fimbria fornix. Two weeks after the lesions were made, CCK mRNA levels were significantly lower in these neurones on the side ipsilateral to the lesion compared with equivalent neurones on the unlesioned side. These findings suggest that axotomizing lesions can change gene expression in denervated target cells, and that CCK mRNA levels in hippocampal interneurones may be modulated by afferent septohippocampal input.

Ganglioside GM1 potentiates NGF action on axotomised medial septal cholinergic neurons.

Transection of the fimbria fornix leads to retrograde degeneration of axotomised septal cholinergic neurons as manifested by loss of choline acetyltransferase and p75NGFR immunoreactivity. Intracerebroventricularly administered nerve growth factor initiated at the time of axotomy can prevent these changes. We have shown that concurrent intraperitoneal administration of GM1 with a low and otherwise unprotective intracerebroventricular dose of nerve growth factor, can also prevent the loss of these fimbria fornix axotomised cholinergic neurons, where GM1 alone does not have this effect. This study further confirms the neuroprotective actions of GM1 and suggests that it may interact to potentiate the effect of nerve growth factor on these axotomised septal cholinergic neurons.

Evidence for a tropic role of brain-derived neurotrophic factor in transplanted embryonic retinae.

Developing retinal axons must follow a stereotypic course directing them to the subcortical visual centres which on arrival they must recognise. Transplantation studies suggest that local substrate cues close to the surface of the brainstem and diffusible factors emanating from the target region are important. To test a role for diffusible factors, we transplanted retinae to the cerebral cortex and have shown that outgrowth can be promoted by BDNF secreting fibroblasts.

Effects of neurotrophins on embryonic retinal outgrowth.

The neurotrophins brain derived neurotrophic factor (BDNF), neurotrophin 3 (NT-3) and neurotrophin 4 (NT-4), as well as their receptors, are expressed in both the developing and adult visual system. In vitro and in vivo studies suggest that BDNF in particular can enhance the survival of developing and injured retinal ganglion cells. We have previously shown that BDNF secreted by transgenic fibroblasts promotes outgrowth from embryonic retinae when cotransplanted into the cerebral cortex. The roles of NT-3 and NT-4 were investigated in this system along with BDNF, on retinal neuronal outgrowth, both on in vivo retinal transplants and on in vitro retinal explant cultures. Our results confirm that BDNF promotes retinal outgrowth of embryonic retinae both in vivo, and in vitro. NT4 was shown only to promote retinal outgrowth in vitro in the presence of proliferating glia. NT-3 was shown to have no effect on embryonic retinal outgrowth in vivo or in vitro. While other molecules have been proposed to play a role, the present results, together with evidence for BDNF in the developing superior colliculus and receptors on retinal cells, argue for an important role for BDNF in normal retinal neuronal outgrowth, with NT-4 playing a secondary role.

Optic target regulation of NADPH-diaphorase by larval retinal axons in Drosophila.

Development of the visual system in Drosophila requires the establishment of precise retinotopic connections between photoreceptors and their synaptic targets in the central nervous system. Nitric oxide (NO) has been implicated as a candidate signal involved in the establishment of retinal projection patterns. In this study the expression of NADPH-diaphorase in the lamina of Drosophila, and by implication nitric oxide synthase (NOS), was investigated in larvae with varying degrees of retinal innervation. NADPH-diaphorase expression was seen to increase in the lamina and eye disk following retinal neuronal death in eye specific pro-apoptotic larvae (pGMR-hid) compared to wild type larvae, and was lower in the lamina in absent or reduced retinal innervation mutants (eyes absent and sine oculis). Retinal innervation is seen to regulate the expression of NADPH-diaphorase expression in target structures.

Single dermatome analgesia sparing in an obstetric patient following previous radiation to that region.

We present a case of an obstetric patient with prior radiation therapy for Hodgkins lymphoma to the right hip, right flank region and lumbar spine, who suffered persistent right sided L1 dermatone distribution sensory and analgesia sparing after routine epidural placement despite additional boluses of local anesthetic. We postulate that the previous radiation therapy received by our patient left sufficient epidural fibrosis as a barrier to prevent spread of local anesthetic to cover the L1 dermatome. Subsequent replacement, using a combined spinal-epidural technique at a higher lumbar space, overcame this obstruction. In patients who have received substantial radiation therapy to the lumbosacral region in the past, awareness of this potential problem may assist in clinical management.

Minimum effective dose of spinal ropivacaine with and without fentanyl for postpartum tubal ligation.

BACKGROUND: Ropivacaine may be the ideal spinal anesthetic for postpartum tubal ligation due to its medium duration of action, low incidence of side effects and possibly reduced post-anesthetic care unit (PACU) stay. METHODS: Two prospective up-down sequential allocation studies were performed using hyperbaric spinal ropivacaine via a combined spinal-epidural anesthetic technique for patients undergoing postpartum tubal ligation. The first study was performed using an initial dose of 12.5 mg hyperbaric ropivacaine, which was adjusted in testing intervals of 0.5 mg. The second study used an initial dose of 16 mg hyperbaric ropivacaine, a testing interval of 1.0mg, and a fixed dose of fentanyl 10 µg. The need to supplement the block with intravenous or epidural agents was defined as a failure. Failures were treated with epidural lidocaine. RESULTS: The first and second studies recruited 24 and 17 patients, respectively. The median effective dose (ED50) for hyperbaric spinal ropivacaine was 16.4 mg (95% CI 13.7-19) with an ED95 estimate of 21.9 mg. The median effective dose of spinal ropivacaine with fentanyl 10 µg was 17.0 mg (95% CI 15.4-18.7) with an ED95 estimate of 21.3 mg. When data were combined, the overall ED50 for ropivacaine was 16.7 mg (95% CI 15.1-18.4) with an ED95 estimate of 22.5 mg (95% CI 16.3-28.8). A T8 block was not achieved in 4 patients receiving spinal ropivacaine alone, and 1 patient receiving spinal ropivacaine with fentanyl. The majority (82%) of patients who did not receive epidural local anesthetic supplementation had recovery of motor block within 60 min following PACU admission. CONCLUSION: Spinal hyperbaric ropivacaine 22 mg with or without fentanyl 10 µg could be used for postpartum tubal ligation surgery.

Obese parturients have lower epidural local anaesthetic requirements for analgesia in labour.

BACKGROUND: There are no studies comparing local anaesthetic requirements for obese and normal parturients. Obesity has been associated with a higher incidence of Caesarean section and higher levels of epidural block have also been found in obese obstetric patients, suggesting they may require less local anaesthetic. The aim of our study was to estimate the minimum local analgesic concentration (MLAC) of bupivacaine for obese and non-obese parturients. METHODS: Otherwise healthy parturients (n=32) requesting epidural analgesia were enrolled in this up-down sequential allocation study. Women were in active labour (3-6 cm cervical dilatation) with visual analogue pain scores (VAPS) >40/100 mm. Subjects with BMI >30 kg m(-2) were allocated to the obese group and BMI < or = 30 kg m(-2) were allocated to the normal group. The initial epidural dose for both groups was 20 ml 0.1% w/v bupivacaine (20 mg), with a dosing increment of 0.01% w/v VAPS < or = 10/100 mm defined effective analgesia. The MLAC was estimated using up-down reversals and probit regression with P<0.05 as significant. RESULTS: Groups were similar except for BMI and weight (P<0.001). Local anaesthetic requirements were significantly (P<0.001) reduced by a factor of 1.68 (95% CI 1.32-2.29) in the obese group, with significantly higher initial level of block (P<0.001). CONCLUSION: We found obese parturients to have significantly decreased epidural bupivacaine analgesic requirements. A contributing factor to obese patients having more difficult labours may be that relatively larger doses of local anaesthetic are administered than actually required. It may be worth considering lowering the concentrations and doses with which we initiate analgesia in obese parturients.