A systematic review of the effects of residency training on patient outcomes

BACKGROUND

Residents are vital to the clinical workforce of today and tomorrow. Although in training to become specialists, they also provide much of the daily patient care. Residency training aims to prepare residents to provide a high quality of care. It is essential to assess the patient outcome aspects of residency training, to evaluate the effect or impact of global investments made in training programs. Therefore, we conducted a systematic review to evaluate the effects of relevant aspects of residency training on patient outcomes.

METHODS

The literature was searched from December 2004 to February 2011 using MEDLINE, Cochrane, Embase and the Education Resources Information Center databases with terms related to residency training and (post) graduate medical education and patient outcomes, including mortality, morbidity, complications, length of stay and patient satisfaction. Included studies evaluated the impact of residency training on patient outcomes.

RESULTS

Ninety-seven articles were included from 182 full-text articles of the initial 2,001 hits. All studies were of average or good quality and the majority had an observational study design. Ninety-six studies provided insight into the effect of 'the level of experience of residents' on patient outcomes during residency training. Within these studies, the start of the academic year was not without risk (five out of 19 studies), but individual progression of residents (seven studies) as well as progression through residency training (nine out of 10 studies) had a positive effect on patient outcomes. Compared with faculty, residents' care resulted mostly in similar patient outcomes when dedicated supervision and additional operation time were arranged for (34 out of 43 studies). After new, modified or improved training programs, patient outcomes remained unchanged or improved (16 out of 17 studies). Only one study focused on physicians' prior training site when assessing the quality of patient care. In this study, training programs were ranked by complication rates of their graduates, thus linking patient outcomes back to where physicians were trained.

CONCLUSIONS

The majority of studies included in this systematic review drew attention to the fact that patient care appears safe and of equal quality when delivered by residents. A minority of results pointed to some negative patient outcomes from the involvement of residents. Adequate supervision, room for extra operation time, and evaluation of and attention to the individual competence of residents throughout residency training could positively serve patient outcomes. Limited evidence is available on the effect of residency training on later practice. Both qualitative and quantitative research designs are needed to clarify which aspects of residency training best prepare doctors to deliver high quality care.

Early mobilization in the management of critical illness

Patients undergoing critical illness and mechanical ventilation are at risk of developing neuromuscular and neurocognitive impairments that can impact physical function and quality of life. Mobilizing patients early in the course of critical illness may improve outcomes. Recent literature on early mobilization is reviewed, suggestions for implementation are discussed, and areas for future research are identified.

Preventing ventilator-associated pneumonia: does the evidence support the practice?

Ventilator-associated pneumonia (VAP) is among the most common infections in patients requiring endotracheal tubes with mechanical ventilation. Ventilator-associated pneumonia is associated with increased hospital costs, a greater number of days in the intensive care unit, longer duration of mechanical ventilation, and higher mortality. Despite widely accepted recommendations for interventions designed to reduce rates of VAP, few studies have assessed the ability of these interventions to improve patient outcomes. As the understanding of VAP advances and new technologies to reduce VAP become available, studies should directly assess patient outcomes before the health care community implements specific prevention approaches in clinical practice.

The surgical intensive care unit optimal mobility score predicts mortality and length of stay

OBJECTIVES

To test if the surgical intensive care unit optimal mobility score predicts mortality and intensive care unit and hospital length of stay.

DESIGN

Prospective single-center cohort study.

SETTING

Surgical intensive care unit of the Massachusetts General Hospital.

PATIENTS

One hundred thirteen consecutive patients admitted to the surgical intensive care unit.

INVESTIGATIONS

We tested the hypotheses that the surgical intensive care unit optimal mobility score independent of comorbidity index, Acute Physiology and Chronic Health Evaluation II, creatinine, hypotension, hypernatremia, acidosis, hypoxia, and hypercarbia predicts hospital mortality, surgical intensive care unit and total hospital length of stay.

MEASUREMENTS AND MAIN RESULTS

Two nurses independently predicted the patients' mobilization capacity by using the surgical intensive care unit optimal mobility score the morning after admission, whereas a third nurse recorded the achieved mobilization levels of patients at the end of the day. A multidisciplinary expert team measured patients' grip strength and assessed their predicted mobilization capacity independently. Multivariate analysis revealed that the surgical intensive care unit optimal mobility score was the only independent predictor of mortality. Surgical intensive care unit optimal mobility score, hypotension, and hypernatremia (>144 mmol/L) independently predicted intensive care unit length of stay, whereas the surgical intensive care unit optimal mobility score and hypernatremia predicted total hospital length of stay. The Acute Physiology and Chronic Health Evaluation II score was not identified in the multivariate analysis. The surgical intensive care unit optimal mobility score was also a reliable and valid instrument in predicting achieved mobilization levels of patients.

CONCLUSIONS

In surgical critically ill patients presenting without preexisting impairment of functional mobility, the surgical intensive care unit optimal mobility score is a reliable and valid tool to predict mortality and intensive care unit and hospital length of stay.

Anesthetics isoflurane and desflurane differently affect mitochondrial function, learning, and memory

OBJECTIVE

There are approximately 8.5 million Alzheimer disease (AD) patients who need anesthesia and surgery care every year. The inhalation anesthetic isoflurane, but not desflurane, has been shown to induce caspase activation and apoptosis, which are part of AD neuropathogenesis, through the mitochondria-dependent apoptosis pathway. However, the in vivo relevance, underlying mechanisms, and functional consequences of these findings remain largely to be determined.

METHODS

We therefore set out to assess the effects of isoflurane and desflurane on mitochondrial function, cytotoxicity, learning, and memory using flow cytometry, confocal microscopy, Western blot analysis, immunocytochemistry, and the fear conditioning test.

RESULTS

Here we show that isoflurane, but not desflurane, induces opening of mitochondrial permeability transition pore (mPTP), increase in levels of reactive oxygen species, reduction in levels of mitochondrial membrane potential and adenosine-5'-triphosphate, activation of caspase 3, and impairment of learning and memory in cultured cells, mouse hippocampus neurons, mouse hippocampus, and mice. Moreover, cyclosporine A, a blocker of mPTP opening, attenuates isoflurane-induced mPTP opening, caspase 3 activation, and impairment of learning and memory. Finally, isoflurane may induce the opening of mPTP via increasing levels of reactive oxygen species.

INTERPRETATION

These findings suggest that desflurane could be a safer anesthetic for AD patients as compared to isoflurane, and elucidate the potential mitochondria-associated underlying mechanisms, and therefore have implications for use of anesthetics in AD patients, pending human study confirmation.

[Evaluation of the efficiency of pharmacological antiemetic prophylaxis in different risk groups after general anaesthesia in the surgical population of Catalonia]

OBJECTIVE

To assess the efficiency of pharmacological antiemetic prophylaxis in patients subjected to surgery under general anaesthetic in different postoperative nausea and vomiting (NVPO) risk groups.

MATERIAL AND METHODS

A randomised, observational, prospective and multicentre cohort study was conducted. The study included 1239 patients from 26 hospitals who were subjected to elective surgery under general anaesthesia. The data collected included, demographic characteristics, the NVPO risk factors, anaesthetic technique, type of surgery, the duration, fluid therapy, antiemetic prophylaxis administered, and the incidence of NVPO in the first 24h after surgery. A stratified analysis (low, moderate and high risk) was performed with the intention of evaluating the relationship between prophylaxis and NVPO using a logistic regression model adjusted for propensity score. The number of patients needed to treat (NNT) to prevent an NVPO episode was then calculated for each of the strata.

RESULTS

The incidence of NVPO in the low risk stratum was 21.6% without prophylaxis and 8.6% with prophylaxis, 31.3% compared to 17.7% in the moderate risk, and 46.5% compared to 32.7% in the high risk group. There was a significant protective effect in the three strata (odds ratio between treated and untreated patients) and in the NNT (95% CI) was 7 (5-11) in the low risk stratum, 7 (5-13) in that of the moderate risk, and 6 (4-16) in the high risk.

CONCLUSIONS

The efficiency of pharmacological antiemetic prophylaxis in patients subjected to surgery under general anaesthesia was similar in all risk groups. Not providing antiemetic prophylaxis in low risk patients may not be justified due to the cost-effectiveness criteria. Future clinical guidelines to improve the quality of health care of patients operated on under general anaesthesia should consider the advantages of a universal NVPO prophylaxis.

Effect of synthetic aβ peptide oligomers and fluorinated solvents on Kv1.3 channel properties and membrane conductance

The impact of synthetic amyloid β (1–42) (Aβ_1–42) oligomers on biophysical properties of voltage-gated potassium channels Kv 1.3 and lipid bilayer membranes (BLMs) was quantified for protocols using hexafluoroisopropanol (HFIP) or sodium hydroxide (NaOH) as solvents prior to initiating the oligomer formation. Regardless of the solvent used Aβ_1–42 samples contained oligomers that reacted with the conformation-specific antibodies A11 and OC and had similar size distributions as determined by dynamic light scattering. Patch-clamp recordings of the potassium currents showed that synthetic Aβ_1–42 oligomers accelerate the activation and inactivation kinetics of Kv 1.3 current with no significant effect on current amplitude. In contrast to oligomeric samples, freshly prepared, presumably monomeric, Aβ_1–42 solutions had no effect on Kv 1.3 channel properties. Aβ_1–42 oligomers had no effect on the steady-state current (at −80 mV) recorded from Kv 1.3-expressing cells but increased the conductance of artificial BLMs in a dose-dependent fashion. Formation of amyloid channels, however, was not observed due to conditions of the experiments. To exclude the effects of HFIP (used to dissolve lyophilized Aβ_1–42 peptide), and trifluoroacetic acid (TFA) (used during Aβ_1–42 synthesis), we determined concentrations of these fluorinated compounds in the stock Aβ_1–42 solutions by ¹⁹F NMR. After extensive evaporation, the concentration of HFIP in the 100× stock Aβ_1–42 solutions was ∼1.7 μM. The concentration of residual TFA in the 70× stock Aβ_1–42 solutions was ∼20 μM. Even at the stock concentrations neither HFIP nor TFA alone had any effect on potassium currents or BLMs. The Aβ_1–42 oligomers prepared with HFIP as solvent, however, were more potent in the electrophysiological tests, suggesting that fluorinated compounds, such as HFIP or structurally-related inhalational anesthetics, may affect Aβ_1–42 aggregation and potentially enhance ability of oligomers to modulate voltage-gated ion channels and biological membrane properties.

Acute pulmonary edema secondary to upper airway obstruction by bilateral vocal cord paralysis after total thyroidectomy -A case report-

This paper reports the case of a 65-year-old woman with a history of mild arterial hypertension who presented with acute pulmonary edema immediately after a total thyroidectomy. The edema was found to have been caused by an acute upper airway obstruction secondary to bilateral vocal cord paralysis. Her pulmonary edema resolved with treatment including reintubation, mechanical ventilation with positive end-expiratory pressure, diuretics, morphine, and fluid restriction. This report discusses the possible pathogenesis of this rare clinical situation. This case highlights the possibility of an acute upper airway obstruction caused by bilateral vocal cord paralysis after a total thyroidectomy and the need for prompt treatment to prevent the development of pulmonary edema.

Muscle strength assessment in critically ill patients with handheld dynamometry: an investigation of reliability, minimal detectable change, and time to peak force generation

PURPOSE

Dynamometry is an objective tool for volitional strength evaluation that may overcome the limited sensitivity of the Medical Research Council scale for manual muscle tests, particularly at grades 4 and 5. The primary aims of this study were to investigate the reliability, minimal detectable change, and time to peak muscle force, measured with portable dynamometry, in critically ill patients.

MATERIALS AND METHODS

Isometric hand grip, elbow flexion, and knee extension were measured with portable dynamometry.

RESULTS

Interrater consistency (intraclass correlation coefficient [95% confidence interval]) (0.782 [0.321-0.930] to 0.946 [0.840-0.982]) and test-retest agreement (0.819 [0.390-0.943] to 0.918 [0.779-0.970]) were acceptable for all dynamometry forces, with the exception of left elbow flexion. Despite generally good reliability, a mean change (upper 95% confidence interval) of 2.8 (7.8) kg, 1.9 (5.2) kg, and 2.6 (7.1) kg may be required from a patient's baseline force measurement of right grip, elbow flexion, and knee extension to reflect real force changes. There was also a delay in the time for critically ill patients to generate peak muscle forces, compared with healthy controls (P ≤ .001).

CONCLUSIONS

Dynamometry can provide reliable measurements in alert critically ill patients, but moderate changes in strength may be required to overcome measurement error, during the acute recovery period. Deficits in force timing may reflect impaired neuromuscular control.

What is the best method for estimating the burden of severe sepsis in the United States?

PURPOSE

The aim of the study was to compare estimates of hospitalizations, outcomes, and costs produced by 2 approaches for defining severe sepsis.

METHODS

We used the Nationwide Inpatient Sample to study adults hospitalized in the United States in 2007. We defined severe sepsis using 2 previously published algorithms: (1) the presence of a principal or secondary diagnosis of septicemia combined with organ dysfunction or (2) the presence of a principal or secondary diagnosis of septicemia or another infection (eg, pneumonia) combined with organ dysfunction. For each approach, we calculated the weighted frequency of hospitalizations, population-based mortality rates, and geometric mean costs.

RESULTS

A total of 719099 (SD, 16676) hospitalizations had a diagnosis of septicemia and a diagnosis of organ dysfunction. A total of 2.5 million hospitalizations were recorded, with a diagnosis code for either septicemia or infection combined with a diagnosis code for organ dysfunction. Hospitalizations without a diagnosis code for septicemia had lower rates of respiratory failure (35% vs 51%, P < .001) or shock (20% vs 46%, P < .001), lower in-hospital mortality (8% vs 29%, P < .001), and lower mean costs.

CONCLUSIONS

An approach that requires a diagnosis code for septicemia and a diagnosis code for organ dysfunction yields estimates of disease burden and outcomes that are more consistent with chart-based studies.

[Acute negative pressure pulmonary edema: illustration from a unusual clinical case following a postoperative recurrent laryngeal nerve palsy]

Acute postoperative negative pressure pulmonary edema (NPPE) is a respiratory complication due to upper airway obstruction occurring most commonly in the postoperative period. Pathophysiologically, NPPE is explained by the abrupt generation of highly negative intrathoracic pressure that lead to fluid transudation from the pulmonary capillaries. This observation reports an unusual case of a young patient who has undergone total thyroidectomy for multinodular goiter. The postoperative period was marked by the occurrence of bilateral recurrent laryngeal nerve palsy that was complicated by a NPPE. The outcome was favorable after mechanical ventilation with reversal of NPPE and recovery of the recurrent laryngeal nerve function. This article stresses the importance of prevention of recurrent nerve palsy during thyroid surgery. It also highlights a little known respiratory complication: the NPPE. Understanding the pathophysiology of NPPE, rapid diagnosis and appropriate therapeutic measures could prevent its potential lethal consequences.

A systematic review: the effect of clinical supervision on patient and residency education outcomes

PURPOSE

To summarize the literature regarding the effect of clinical supervision on patient and educational outcomes, especially in light of the recent (2010) Accreditation Council for Graduate Medical Education report that recommends augmented supervision to improve resident education and patient safety.

METHOD

The authors searched the English-language literature from 1966 to 2010 using electronic databases and a hand search. They included studies that described a controlled design, and they have relayed the effects of supervision on patient- and education-related outcomes. Two authors abstracted prescribed data from the reviewed studies. The authors rated the quality of each study using the Medical Education Research Study Quality Instrument.

RESULTS

Twenty-four articles across a variety of specialties (i.e., psychiatry, emergency medicine, surgery, anesthesia, and internal medicine) met inclusion criteria. Studies demonstrated that enhanced supervision in already-supervised activities resulted in improved patient- or education-related outcomes. Studies were limited by small sample sizes, nonrandomized designs, and a lack of objective measures of clinical supervision.

CONCLUSIONS

Enhanced clinical supervision of trainees has been associated with improved patient- and education-related outcomes in published studies. Future work should focus on developing validated measures of the effects of clinical supervision.

Examining the positive effects of exercise in intubated adults in ICU: a prospective repeated measures clinical study

BACKGROUND

Determining the optimal timing and progression of mobility exercise has the potential to affect functional recovery of critically ill adults. This study compared standard care with care delivered using a mobility protocol. We examined the effects of exercise on vital signs and inflammatory biomarkers and the effects of the nurse-initiated mobility protocol on outcomes.

METHODS

Prospective, repeated measures study with a control (standard care) and intervention (protocol) period.

RESULTS

75 heterogeneous subjects admitted to a Medical or Surgical intensive care unit (ICU) were enrolled. In <5% of exercise periods, there was a concerning alteration in respiratory rate or peripheral oxygen saturation; no other adverse events occurred. Findings suggested the use of a protocol with one 20 minute episode of exercise daily for 2 or more days reduced ICU length of stay. Duration of exercise was linked to increased IL-10, suggesting brief episodes of low intensity exercise positively altered inflammatory dysregulation in this sample.

CONCLUSION

A growing body of evidence demonstrates that early, progressive exercise has significant benefits to intubated adults. These results should encourage clinicians to add mobility protocols to the care of ICU adults and lead to future studies to determine optimal "dosing" of exercise in ICU patients.

Measures to prevent nosocomial infections during mechanical ventilation

PURPOSE OF REVIEW

Endotracheal intubation and mechanical ventilation are lifesaving measures in critically ill patients. However, these interventions increase the risk of respiratory infections, particularly ventilator-associated pneumonia (VAP). VAP constitutes a serious burden for the healthcare system and worsens the patient's outcomes; thus, several preventive strategies have been implemented. This communication reviews the current knowledge on VAP pathogenesis and the latest preventive measures.

RECENT FINDINGS

Pathogen-laden oropharyngeal secretions leak across the endotracheal tube (ETT) cuff; thus, a continuous control of the internal cuff pressure and cuffs made of polyurethane improve sealing effectiveness and associated risks of infections. Subglottic secretions aspiration prevents VAP, and the latest evidence demonstrated a reduction in the incidence of late-onset VAP. The role of ETT biofilm in the pathogenesis of VAP is not fully elucidated. Nevertheless, antimicrobial-coated ETTs have showed beneficial effects in VAP incidence. Recent experimental evidence has challenged the benefits associated with the use of the semirecumbent position; yet, these findings need to be corroborated in clinical trials. The latest results from trials testing the effects of selective digestive decontamination (SDD) showed beneficial effects on patients' outcomes, but concerns remain regarding the emergence of bacterial resistance, specifically upon digestive tract re-colonization. The use of oropharyngeal decontamination with antiseptics and the use of probiotics are potential alternatives to SDD.

SUMMARY

There is consistent evidence that strategies affecting the primary mechanisms of VAP pathogenesis efficiently reduce the occurrence of the disease. Preventive measures should be implemented grouped into bundles to improve overall efficacy.

Difficult Airway Society Guidelines for the management of tracheal extubation

Tracheal extubation is a high-risk phase of anaesthesia. The majority of problems that occur during extubation and emergence are of a minor nature, but a small and significant number may result in injury or death. The need for a strategy incorporating extubation is mentioned in several international airway management guidelines, but the subject is not discussed in detail, and the emphasis has been on extubation of the patient with a difficult airway. The Difficult Airway Society has developed guidelines for the safe management of tracheal extubation in adult peri-operative practice. The guidelines discuss the problems arising during extubation and recovery and promote a strategic, stepwise approach to extubation. They emphasise the importance of planning and preparation, and include practical techniques for use in clinical practice and recommendations for post-extubation care.

Hemodynamic stability after intraarterial injection of verapamil for cerebral vasospasm

BACKGROUND

Vasospasm after subarachnoid hemorrhage is a common and potentially life-threatening complication. Treatment of vasospasm may include intraarterial (IA) injections of verapamil into the cerebral vasculature. Clinical experience suggests that the average patient experiences an acute reduction in systemic blood pressure after IA verapamil. Our study objective was to (1) identify the effects of IA injection of verapamil on mean arterial blood pressure (MAP) and heart rate (HR) in patients with cerebral vasospasm and (2) determine the effect of verapamil dose on change in MAP and HR. We hypothesized that (1) selective IA injection of verapamil for treatment of cerebral vasospasm is associated with a reduction in MAP and an increase in HR and (2) the change in MAP and HR are linearly related to the dose of verapamil administered.

METHODS

We prospectively studied subjects with vasospasm scheduled for cerebral angiography with possible IA injection of verapamil. All subjects were given a general anesthetic. Invasive arterial blood pressure and HR were monitored continuously and recorded at 10-second intervals throughout the procedure. We identified the lowest MAP and highest HR before and after verapamil injection. The association between IA verapamil and change in MAP and HR was determined using repeated-measures multivariate regression analysis, adjusting for potential confounding factors (weight, preoperative vasopressor use, and preinjection MAP). Data are reported as adjusted coefficients and 95% confidence intervals (CI).

RESULTS

We included 20 subjects who underwent a total of 46 injections of IA verapamil. On the basis of our multivariate model, on average, each 5 mg of IA verapamil was associated with a 3.5 mm Hg reduction in MAP (95% CI -5.0 to -2.0, P < 0.001). HR was not significantly altered by IA verapamil on both unadjusted and adjusted analyses (nonsignificant increase of 0.4 beats per minute for each 5 mg of IA verapamil, 95% CI -1.6 to 2.4, P = 0.70).

CONCLUSIONS

Under general anesthesia, injection of IA verapamil into cerebral arteries reduces MAP but does not change HR in the average patient. Further research is required to determine the clinical significance of these results.

[Emergency anesthesia, airway management and ventilation in major trauma. Background and key messages of the interdisciplinary S3 guidelines for major trauma patients]

Patients with multiple trauma presenting with apnea or a gasping breathing pattern (respiratory rate <6/min) require prehospital endotracheal intubation (ETI) and ventilation. Additional indications are hypoxia (S(p)O(2)<90% despite oxygen insufflation and after exclusion of tension pneumothorax), severe traumatic brain injury [Glasgow Coma Scale (GCS)<9], trauma-associated hemodynamic instability [systolic blood pressure (SBP)<90 mmHg] and severe chest trauma with respiratory insufficiency (respiratory rate >29/min). The induction of anesthesia after preoxygenation is conducted as rapid sequence induction (analgesic, hypnotic drug, neuromuscular blocking agent). With the availability of ketamine as a viable alternative, the use of etomidate is not encouraged due to its side effects on adrenal function. An electrocardiogram (ECG), blood pressure measurement and pulse oximetry are needed to monitor the emergency anesthesia and the secured airway. Capnography is absolutely mandatory to confirm correct placement of the endotracheal tube and to monitor tube dislocations as well as ventilation and oxygenation in the prehospital and hospital setting. Because airway management is often complicated in trauma patients, alternative devices and a fiber-optic endoscope need to be available within the hospital. Use of these alternative measures for airway management and ventilation should be considered at the latest after a maximum of three unsuccessful intubation attempts. Emergency medical service (EMS) physicians should to be trained in emergency anesthesia, ETI and alternative methods of airway management on a regular basis. Within hospitals ETI, emergency anesthesia and ventilation are to be conducted by trained and experienced anesthesiologists. When a difficult airway or induction of anesthesia is expected, endotracheal intubation should be supervised or conducted by an anesthesiologist. Normoventilation should be the goal of mechanical ventilation. After arrival in the resuscitation room the ventilation will be controlled and guided with the help of arterial blood gas analyses. After temporary removal of a cervical collar, the cervical spine needs to be immobilized by means of manual in-line stabilization when securing the airway.

[Intensive care unit-acquired weakness in the critically ill : critical illness polyneuropathy and critical illness myopathy]

Intensive care unit-acquired weakness (ICUAW) is a severe complication in critically ill patients which has been increasingly recognized over the last two decades. By definition ICUAW is caused by distinct neuromuscular disorders, namely critical illness polyneuropathy (CIP) and critical illness myopathy (CIM). Both CIP and CIM can affect limb and respiratory muscles and thus complicate weaning from a ventilator, increase the length of stay in the intensive care unit and delay mobilization and physical rehabilitation. It is controversially discussed whether CIP and CIM are distinct entities or whether they just represent different organ manifestations with common pathomechanisms. These basic pathomechanisms, however, are complex and still not completely understood but metabolic, inflammatory and bioenergetic alterations seem to play a crucial role. In this respect several risk factors have recently been revealed: in addition to the administration of glucocorticoids and non-depolarizing muscle relaxants, sepsis and multi-organ failure per se as well as elevated levels of blood glucose and muscular immobilization have been shown to have a profound impact on the occurrence of CIP and CIM. For the diagnosis, careful physical and neurological examinations, electrophysiological testing and in rare cases nerve and muscle biopsies are recommended. Nevertheless, it appears to be difficult to clearly distinguish between CIM and CIP in a clinical setting. At present no specific therapy for these neuromuscular disorders has been established but recent data suggest that in addition to avoidance of risk factors early active mobilization of critically ill patients may be beneficial.

Memory Loss, Alzheimer's Disease and General Anesthesia: A Preoperative Concern

BACKGROUND

The long-term cognitive effects of general anesthesia are under intense scrutiny. Here we present 5 cases from 2 academic institutions to analyze some common features where the patient's or the patient family member has made a request to address their concern on memory loss, Alzheimer's disease and general anesthesia before surgery.

METHODS

Records of anesthesia consultation separate from standard preoperative evaluation were retrieved to identify consultations related to memory loss and Alzheimer's disease from the patient and/or patient family members. The identified cases were extensively reviewed for features in common. We used Google® (http://www. google.com/) to identify available online information using "anesthesia memory loss" as a search phrase.

RESULTS

Five cases were collected as a specific preoperative consultation related to memory loss, Alzheimer's disease and general anesthesia from two institutions. All of the individuals either had perceived memory impairment after a prior surgical procedure with general anesthesia or had a family member with Alzheimer's disease. They all accessed public media sources to find articles related to anesthesia and memory loss. On May 2nd, 2011, searching "anesthesia memory loss" in Google yielded 764,000 hits. Only 3 of the 50 Google top hits were from peer-reviewed journals. Some of the lay media postings made a causal association between general anesthesia and memory loss and/or Alzheimer's disease without conclusive scientific literature support.

CONCLUSION

The potential link between memory loss and Alzheimer's disease with general anesthesia is an important preoperative concern from patients and their family members. This concern arises from individuals who have had history of cognitive impairment or have had a family member with Alzheimer disease and have tried to obtain information from public media. Proper preoperative consultation with the awareness of the lay literature can be useful in reducing patient and patient family member's preoperative anxiety related to this concern.

Multimodal therapies for postoperative nausea and vomiting, and pain

Postoperative nausea and vomiting (PONV) and pain are two of the major concerns for patients presenting for surgery. The causes of PONV are multifactorial and can largely be categorized as patient risk factors, anaesthetic technique, and surgical procedure. Antiemetics work on several different receptor sites to prevent or treat PONV. This is probably why numerous studies have now demonstrated that using more than one antiemetic is usually more effective and results in fewer side-effects than simply increasing the dose of a single antiemetic. A multimodal approach to PONV should not be limited to drug therapy alone but should involve a holistic approach starting before operation and continuing intraoperatively with risk reduction strategies to which are added prophylactic antiemetics according to the assessed patient risk for PONV. With the increasing understanding of the pathophysiology of acute pain, especially the occurrence of peripheral and central hypersensitization, it is unlikely that a single drug or intervention is sufficiently broad in its action to be adequately effective, especially with moderate or greater pain. Although morphine and its congeners are usually the foundation of pain management regimens, as their dose increases so does the incidence of side-effects. Thus, the approach for the management of acute postoperative pain is to use multiple drugs or modalities (e.g. regional anaesthesia) to maximize pain relief and reduce side-effects.

Stress-induced cardiomyopathy after negative pressure pulmonary edema during emergence from anesthesia -A case report-

Stress-induced cardiomyopathy (SICM) presenting as an acute myocardial dysfunction is characterized by transient left ventricular wall motion abnormality, which has been known to be associated with excessive catecholamine production caused due to various types of stress. Sympathetic hyperactivity is common during the perioperative period, and reports of SICM occurring during this period have actually increased. We present a case of SICM following negative pressure pulmonary edema due to upper airway obstruction during emergence from anesthesia. Excessive catecholamine release in response to respiratory difficulty could have been the underlying inciting factor.

Hemodynamic management of subarachnoid hemorrhage

Hemodynamic augmentation therapy is considered standard treatment to help prevent and treat vasospasm and delayed cerebral ischemia. Standard triple-H therapy combines volume expansion (hypervolemia), blood pressure augmentation (hypertension), and hemodilution. An electronic literature search was conducted of English-language papers published between 2000 and October 2010 that focused on hemodynamic augmentation therapies in patients with subarachnoid hemorrhage. Among the eligible reports identified, 11 addressed volume expansion, 10 blood pressure management, 4 inotropic therapy, and 12 hemodynamic augmentation in patients with unsecured aneurysms. While hypovolemia should be avoided, hypervolemia did not appear to confer additional benefits over normovolemic therapy, with an excess of side effects occurring in patients treated with hypervolemic targets. Overall, hypertension was associated with higher cerebral blood flow, regardless of volume status (normo- or hypervolemia), with neurological symptom reversal seen in two-thirds of treated patients. Limited data were available for evaluating inotropic agents or hemodynamic augmentation in patients with additional unsecured aneurysms. In the context of sparse data, no incremental risk of aneurysmal rupture has been reported with the induction of hemodynamic augmentation.

Long-term outcomes in elderly surgical patients

Anesthesia has developed to the point where long-term outcomes are important endpoints. Elderly patients are becoming an increasingly large part of most surgical practices, consistent with demographic shifts. Long-term outcomes are particularly important for this group. In this review, we discuss functional outcomes in the elderly. We describe the areas of cognitive change and frailty, both of which are specific to the elderly. We also discuss prevention of surgical infections and emerging evidence around hemodynamic alterations in the operating room and their impact on long-term outcomes.

Negative pressure pulmonary edema following bronchospasm

Negative pressure pulmonary edema (NPPE) is an important cause of noncardiogenic pulmonary edema but is rarely reported in the setting of bronchospasm. A 43-year-old woman with severe reactive airway disease suffered an episode of severe bronchospasm after endotracheal extubation following an otherwise uneventful general anesthetic. Subsequently, she developed clinical and radiographic signs of pulmonary edema in the absence of other symptoms of acute left-sided heart failure, leading to the diagnosis of noncardiogenic pulmonary edema. She received noninvasive positive pressure ventilation for a few hours, after which her clinical and radiologic signs and symptoms of pulmonary edema were greatly improved. This clinical scenario strongly suggests NPPE. We submit that it is possible to create NPPE by generating highly negative intrathoracic pressures in the setting of severe bronchospasm.

Recovery after spinal cord infarcts: long-term outcome in 115 patients

OBJECTIVE

To investigate the long-term outcome of patients with spinal cord infarct (SCI) and identify prognostic predictors.

METHODS

We reviewed 115 patients with SCI treated between 1990 and 2007. Severity of impairment was defined using the American Spinal Injury Association (ASIA) scoring. Functional outcome endpoints were ambulatory status, need for bladder catheterization, and pain.

RESULTS

Mean age was 64 years; 72 (62.6%) patients were men. A total of 45% of infarcts were perioperative (69% aortic surgeries). A total of 68% reached maximal deficit within 1 hour (mean = 5 hours). Impairment at nadir was ASIA A 23%, B 26%, C 14%, and D 37%. A total of 75/93 (81%) patients studied with MRI had cord signal abnormality. At nadir, 81% required wheelchair, 86% required catheterization, and 32% had pain. At last follow-up (mean = 3 years), 23% had died. Among survivors, 42% required a wheelchair, 54% required catheterization, and 29% had pain upon last follow-up. Of 74 patients using a wheelchair at hospital dismissal, 41% were walking by final follow-up. Of 83 patients catheterized at dismissal, 33% were catheter-free at last follow-up. Older age (p < 0.0001), increased severity of impairment at nadir (p = 0.02), and peripheral vascular disease (p = 0.003) were independent risk factors for mortality. Severe impairment (ASIA A/B) at nadir predicted wheelchair use (p < 0.0001) and bladder catheterization (p < 0.0001) at last follow-up.

CONCLUSIONS

Gradual improvement in not uncommon after spinal cord infarction and it may continue long after hospital dismissal. While severe impairment at nadir is the strongest predictor of poor functional outcome, meaningful recovery is also possible in a substantial minority of these patients.

Airway challenges in critical care

Airway management in the intensive care unit is more problematic than during anaesthesia. In general, critically ill patients have less physiological reserve and complications are more common, both during the initial airway intervention (which includes risks associated with induction of anaesthesia), and later once the airway has been secured. Despite these known risks, those managing the airway of a critically ill patient, particularly out of hours, may be relatively inexperienced. Solutions to these challenging airway problems include: recognition of those patients with a potential airway problem; implementation of a plan to deal with their airway; immediate availability of a difficult airway trolley; use of capnography for every airway intervention and continuously in all ventilator-dependent patients; and appropriate training of all intensive care unit staff including use of simulation.

Sensorimotor function of the upper-airway muscles and respiratory sensory processing in untreated obstructive sleep apnea

Numerous studies have demonstrated upper-airway neuromuscular abnormalities during wakefulness in snorers and obstructive sleep apnea (OSA) patients. However, the functional role of sensorimotor impairment in OSA pathogenesis/disease progression and its potential effects on protective upper-airway reflexes, measures of respiratory sensory processing, and force characteristics remain unclear. This study aimed to gain physiological insight into the potential role of sensorimotor impairment in OSA pathogenesis/disease progression by comparing sensory processing properties (respiratory-related evoked potentials; RREP), functionally important protective reflexes (genioglossus and tensor palatini) across a range of negative pressures (brief pulses and entrained iron lung ventilation), and tongue force and time to task failure characteristics between 12 untreated OSA patients and 13 controls. We hypothesized that abnormalities in these measures would be present in OSA patients. Upper-airway reflexes (e.g., genioglossus onset latency, 20 ± 1 vs. 19 ± 2 ms, P = 0.82), early RREP components (e.g., P1 latency 25 ± 2 vs. 25 ± 1 ms, P = 0.78), and the slope of epiglottic pressure vs. genioglossus activity during iron lung ventilation (-0.68 ± 1.0 vs. -0.80 ± 2.0 cmH(2)O/%max, P = 0.59) were not different between patients and controls. Maximal tongue protrusion force was greater in OSA patients vs. controls (35 ± 2 vs. 27 ± 2 N, P < 0.01), but task failure occurred more rapidly (149 ± 24 vs. 254 ± 23 s, P < 0.01). Upper-airway protective reflexes across a range of negative pressures as measured by electromyography and the early P1 component of the RREP are preserved in OSA patients during wakefulness. Consistent with an adaptive training effect, tongue protrusion force is increased, not decreased, in untreated OSA patients. However, OSA patients may be vulnerable to fatigue of upper-airway dilator muscles, which could contribute to disease progression.

Perioperative pulmonary complications

PURPOSE OF REVIEW

This article reviews current concepts in perioperative pulmonary management.

RECENT FINDINGS

Preoperative risk assessment tools for perioperative pulmonary complications (POPCs) are evolving for both children and adults. Intraoperative management strategies have a demonstrable effect on outcomes. Late POPCs may be preceded by clinical signs.

SUMMARY

POPCs are common and lead to significant resource utilization. Optimal POPC risk mitigation must span all phases of surgical care. Preoperative assessment may identify patients at risk and effectively lower their risk by identifying targeted interventions. Intra-operative strategies impact postoperative outcome. POPCs continue to be a concern for several days postoperatively. We review the current literature on this broad subject with a focus on implementable interventions for the clinician.

The effects of isoflurane and desflurane on cognitive function in humans

BACKGROUND

The etiology of postoperative cognitive decline (POCD) remains to be determined. Anesthetic isoflurane, but not desflurane, may induce neurotoxicity. However, the functional consequences of these effects have not been assessed. We therefore performed a pilot study to determine the effects of isoflurane and desflurane on cognitive function in humans.

METHODS

The subjects included patients who had lower extremity or abdominal surgery under spinal anesthesia alone (S, n = 15), spinal plus desflurane anesthesia (SD, n = 15), or spinal plus isoflurane anesthesia (SI, n = 15) by randomization. Each of the subjects received cognitive tests immediately before and 1 week after anesthesia and surgery administered by an investigator who was blinded to the anesthesia regimen. POCD was defined using the scores from each of these tests.

RESULTS

We studied 45 subjects, 24 males and 21 females. The mean age of the subjects was 69.0 ± 1.9 years. There was no significant difference in age and other characteristics among the treatment arms. The mean number of cognitive function declines in the S, SD, and SI groups was 1.13, 1.07, and 1.40, respectively. POCD incidence after SI (27%), but not SD (0%), anesthesia was higher than that after S (0%), P = 0.028 (3-way comparison).

CONCLUSION

These findings from our pilot study suggest that isoflurane and desflurane may have different effects on postoperative cognitive function, and additional studies with a larger sample size and longer times of follow-up testing are needed.

Postoperative sepsis

PURPOSE OF REVIEW

Postoperative sepsis is a major cause of surgical associated morbidity and mortality. Our goal is to describe its incidence, pathophysiology, and contributing factors. In addition, we will review preventive measures and treatment options that may possibly reduce its healthcare burden.

RECENT FINDINGS

We review epidemiologic data and clinical tools presented in multiple current studies, which may help lower incidence and improve outcome of postoperative sepsis.

SUMMARY

The incidence of postoperative sepsis has not declined over the past years, although mortality is trending downwards. Several biochemical and genetic markers may allow early diagnosis. Prevention and prompt treatment may lower mortality.