Hector Vila

The efficacy and safety of pain management before and after implementation of hospital-wide pain management standards: is patient safety compromised by treatment based solely on numerical pain ratings?

Inadequate analgesia in hospitalized patients prompted the Joint Commission on Accreditation of Healthcare Organizations in 2001 to introduce standards that require pain assessment and treatment. In response, many institutions implemented treatment guided by patient reports of pain intensity indexed with a numerical scale. Patient safety associated with treatment of pain guided by a numerical pain treatment algorithm (NPTA) has not been examined. We reviewed patient satisfaction with pain control and opioid-related adverse drug reactions before and after implementation of our NPTA. Patient satisfaction with pain management, measured on a 1–5 scale, significantly improved from 4.13 to 4.38 (P < 0.001) after implementation of an NPTA. The incidence of opioid over sedation adverse drug reactions per 100,000 inpatient hospital days increased from 11.0 pre-NPTA to 24.5 post-NPTA (P < 0.001). Of these patients, 94% had a documented decrease in their level of consciousness preceding the event. Although there was an improvement in patient satisfaction, we experienced a more than two-fold increase in the incidence of opioid over sedation adverse drug reactions in our hospital after the implementation of NPTA. Most adverse drug reactions were preceded by a documented decrease in the patients level of consciousness, which emphasizes the importance of clinical assessment in managing pain.

Capnography accurately detects apnea during monitored anesthesia care

Apnea and airway obstruction are common during monitored anesthesia care (MAC). Because their early detection is essential, we sought to measure the efficacy of capnography as an indicator of apnea during MAC at a variety of oxygen flow rates compared with thoracic impedance. Anesthesia care providers using standard American Society of Anesthesiologists monitors were blinded to capnography and thoracic impedance monitoring. Ten (26%) of the 39 patients studied developed 20 s of apnea; none was detected by the anesthesia provider, but all were detected by capnography and impedance monitoring. There was no difference in detection rates between the two methods. Higher oxygen flow rates decreased the amplitude of the capnograph but did not interfere with apnea detection. This pilot study revealed that apnea of at least 20 s in duration may occur in every fourth patient undergoing MAC. Although these episodes were undetected by the anesthesia provider, they were reliably detected by both capnography and respiratory plethysmography. Monitoring of nasal end-tidal CO2 is an important way to improve safety in patients undergoing MAC.

Anesthetic complications 14 hours after the use of crack cocaine.

PMEFV curve) is grossly distorted (Figure 2). In our study, we analyzed the initial plateau (point D) and referred to initial “peak” flow as shown in the figure in the published article. We apologize that this was not explained more clearly. Figure 2 shows the curve generated 30 min after interscalene block in the same patient from the published article, compared to the patient’s normal baseline MEFV curve. A normal PMEFV curve peak flow from the same starting volume would be expected to exceed point E. The fact that flow eventually exceeded a value on the effort independent portion of the curve at the same lung volume (point F), we believe, is of less interest. We feel that this grossly distorted curve with reduced early flow is evidence that the intact diaphragm contributes to normal forced expiration. The PEFR data referred to in Table 1 of the published article (1) indeed were measured at the same lung volume, referenced to residual volume.

Succinylcholine for Emergency Airway Rescue in Class B Ambulatory Facilities: The Society for Ambulatory Anesthesia Position Statement.

Procedures in class B ambulatory facilities are performed exclusively with oral or IV sedative-hypnotics and/or analgesics. These facilities typically do not stock dantrolene because no known triggers of malignant hyperthermia (ie, inhaled anesthetics and succinylcholine) are available. This article argues that, in the absence of succinylcholine, the morbidity and mortality from laryngospasm can be significant, indeed, higher than the unlikely scenario of succinylcholine-triggered malignant hyperthermia. The Society for Ambulatory Anesthesia (SAMBA) position statement for the use of succinylcholine for emergency airway management is presented.

Office-based anesthesia

Office surgery is defined as any surgical or invasive procedure performed in a location outside a hospital, hospital outpatient department, ambulatory surgery center (ASC), or other diagnostic and treatment center which results in a patient stay of less than 24 hours. All perioperative care (i.e., preoperative assessment and preparation, operation, and postoperative recovery) is usually performed in a one-operating room (OR) suite within a physician’s office. Generally speaking, office surgical procedures should not result in the loss of more than 10% of estimated blood volume in a patient with normal hemoglobin, should last less than 6 hours, and should not involve major intracranial, intrathoracic, or intra-abdominal operations. They are non-emergent and not life-threatening in nature. By contrast, hospital-based ambulatory surgery units and ASCs are licensed by the state and frequently contain more than one OR and provide services for multiple surgeons. The advantages of office surgery include the following: Lower cost Greater privacy and convenience for the patient More control over surgical scheduling Potential reimbursement advantages to the surgeon These advantages have led to the proliferation of office surgical procedures since the year 2000.

Normal bispectral index values in healthy volunteers.

To the Editor:—We read with great scientific interest the study of Vuyk et al. reporting three cases in which volunteers receiving combinations of propofol and midazolam remained responsive to verbal command although the Bispectral Index (BIS) values were at, or just above, 40, the area considered to be associated with adequate hypnosis for surgery (BIS, 40–60). Vuyk et al. note that the electroencephalographic activation induced by both propofol and midazolam has been difficult to interpret. They ascribe the particular low combination of propofol and midazolam, which at these concentrations is not part of the BIS-behavioral database on which the BIS calculation is based, as a possible cause. As a result, the electroencephalographic pattern induced by this combination may well be misinterpreted by the BIS® monitor (Aspect Medical Systems, Newton, MA) as an electroencephalographic pattern associated with a patient experiencing a surgical hypnotic sedation level instead of actually being responsive to verbal commands. This hypothesis is very interesting, but we believe that alone, it is not enough to give a reasonable explanation. Neuromuscular activity impairs BIS monitoring. A biasing effect of the electromyogram on the BIS may explain discrepancies in previous studies assessing BIS in the presence of neuromuscular activity. Electromyographic activity has previously been reported to elevate the BIS, whereas it may be lower in patients receiving neuromuscular blockade. Midazolam and propofol have direct relaxant properties. Midazolam exhibits a well-known myorelaxant effect as a result of a block of inactivated Na channels in skeletal muscle fiber. Moreover, interaction of midazolam, at very low concentrations, with the nicotinic acetylcholine receptor leads to a substantial reduction of the current amplitude, which suggests an additional closed channel block responsible, to some extent, for the muscle-relaxing effects of midazolam. Midazolam is capable of attenuating opioid rigidity. Propofol also provides some degree of muscle relaxation. Mean muscular activity recorded on an electromyography decreases from 100 mV to 10–25 mV as a result of propofol administration, with restoration to previous levels within 10 min. At clinical concentrations, propofol acts on peripheral parts of the motor system, depressing spinal motor neuron excitability. Motor evoked potentials are also affected by propofol. Because of their muscle relaxation properties, propofol and midazolam are used in tetanus management not only for sedation but also for muscle relaxation. These data, taken together, widely indicate that in sedated patients coadministration of both propofol and midazolam may result in a synergic muscle relaxant action on the motor system and therefore in a decrease in BIS value. This hypothesis is consistent with a study reporting that the central part of the motor system is also impaired when propofol is coadministered in a midazolam-fentanyl based anesthesia. The clinical relevance is that when BIS is assessed during or after the coadministration of midazolam and propofol, despite the absence of a neuromuscular blockade, it is necessary to evaluate the potential synergic muscle relaxant action on BIS before making conclusions about depth of sedation or anesthesia. Finally, this hypothesis further supports the wise statement by Vuyk et al. reporting that the BIS is a measure of drug effect, not an independent measure of brain function.