M. Saeed Dhamee

The use of esmolol, nicardipine, or their combination to blunt hemodynamic changes after laryngoscopy and tracheal intubation

Laryngoscopy and tracheal intubation (LTI) often provoke an undesirable increase in blood pressure (BP) and/or heart rate (HR). We tested the premise that nicardipine (NIC) and esmolol (ESM) in combination (COMB) would oppose both. Adult surgical patients received pretreatment (randomized) with IV bolus NIC 30 &mgr;g/kg (n = 31), ESM 1.0 mg/kg (n = 34), or COMB (one-half dose each, n = 32). Peak BP and HR after LTI were compared with controls (CONT;n = 35) with no pretreatment. Anesthetic induction was standardized: IV thiopental (5–7 mg/kg), fentanyl (1–2 &mgr;g/kg), and succinylcholine (1.5 mg/kg). Systolic (S), diastolic (D), and mean (M) BP and HR awake before pretreatment (baseline) were similar in all test groups. No patient was treated for hypotension, bradycardia, or tachycardia after pretreatment or anesthetic induction. Peak HR after LTI was increased versus baseline in CONT and all test groups, but did not differ from CONT among the test groups. Peak SBP and DBP increased versus baseline in CONT, and with ESM and NIC, but not COMB. Peak SBP, DBP, and MBP were increased with ESM versus COMB, and peak DBP with ESM versus NIC. Compared with no pretreatment before the IV induction of general anesthesia, the peak increase in BP after LTI is best blunted by the combination of nicardipine and ESM, compared with either drug alone. No single drug or combination in the doses tested opposed increased HR. Implications Compared with no pretreatment before the IV induction of general anesthesia, the peak increase in blood pressure after laryngoscopy and tracheal intubation is best blunted by the combination of nicardipine and esmolol, compared with either drug alone. No single drug or combination in the doses tested opposed increased heart rate.

Anesthetic Management of Takotsubo Cardiomyopathy: General Versus Regional Anesthesia

u AKOTSUBO CARDIOMYOPATHY (TC) is a newly described cardiac syndrome characterized by an acute nset of reversible left ventricular dysfunction associated ith emotional and physical stress.1-3 It may initially present n the perioperative period with pulmonary edema, electroardiographic (ECG) changes, elevation of cardiac enzymes, nd cardiogenic shock.4-9 The perioperative management of atients with known TC undergoing surgery has not been escribed. The authors report a patient presenting with pulonary edema after general anesthesia and tracheal extubaion. The subsequent perioperative anesthetic management f this patient during the second and third surgical proceures using regional anesthesia without complications is lso described. Adequate -blockade is a strategy for the reatment of patients with TC. Regional anesthesia may be resented as a good alternative to general anesthesia in these hallenging patients.

A case of serotonin syndrome precipitated by fentanyl and ondansetron in a patient receiving paroxetine, duloxetine, and bupropion

To the Editor: Serotonin syndrome [1,2] is caused by stimulation of a subset of serotonin receptors in the brainstem and spinal cord. It may be a potentially life-threatening complication of exposure to multiple serotonergic medications (acting in different ways to increase serotonin levels) such as selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), and monoamine oxidase inhibitors (MAOIs) (Table 1). Other drugs implicated in this syndrome in the presence of SSRIs are analgesics, antibiotics, and anti-nausea and herbal medications (Table 2). We report a case of serotonin syndrome during general anesthesia in a patient requiring mastectomy. A 68 year old, 84 kgwomanwith a diagnosis of infiltrating ductal carcinoma and ductal carcinoma in situ of left breast presented for mastectomy and sentinel node biopsy. Her past medical history was significant for anxiety, depression, right breast cancer (treated), renal insufficiency, hypertension, hypothyroidism, peripheral neuropathy, and autonomic dysreflexia. Her past surgical history was significant for a hernia repair, right mastectomy, and a hysterectomy, with no reported history of anesthetic complications. She had a history of allergic reactions to sulfonamide, levofloxacin (Levaquin), pregabalin (Lyrica), hydrocodone, and latex. She had stopped smoking 20 years earlier. Her physical examination was essentially normal. Her medications included gabapentin, omeprazole, levothyroxine, Lisinopril, oxycodone, fluodricortisone, paroxetine hcl (Paxil), bupropion (Wellbutrin), triamterene/hydrochlorothiazide, duloxetine (Cymbalta), atorvastatin (Lipitor), tiagabine (Gabitril), alendronate (Fosamax), senna, calcium tabs, clonazepam, and a multi-vitamin. She was premedicated with midazolam. After application of standardASAmonitors, anesthesiawas induced with propofol 200 mg, succinylcholine 120 mg, and fentanyl 100μg.A#7mmcuffedendotracheal tubewas placed. Anesthesia was maintained using 3.9% to 7.2% end-tidal desflurane in a 50/50 nitrous oxide and oxygen mixture. Her intraoperative coursewas unremarkable. She received 50μg of fentanyl, 4 mg of ondansetron, and 1.0 mg of hydromorphone towards the end of the surgery. The surgical procedure lasted 105 minutes. She was extubated in the operating room after 20 minutes of discontinuation of desflurane, then taken to the Postanesthesia Care Unit (PACU), where her heart rate (HR) was 96 beats per minute (bpm), blood pressure (BP) 181/73 mmHg, and temperature 37.5°C. In the PACU she seemed confused. She received 100 μg of fentanyl for pain relief. On repeat examination in the PACU, she was agitated and not responding appropriately to verbal commands. Shewas breathing spontaneously at 14breaths/min,with aBPof 180/80 mmHg and HR of 98 bpm. She was hyperreflexic of the lower extremities on neurological examination. She received another 0.4 mg of hydromorphone. She became unresponsive and apneic, and oxygen saturation decreased to below 90%. She was intubated and ventilator support was instituted. Her temperature steadily rose to 39.1°C from 37.1°C at the time of admission to the PACU. Shewas sedated for ventilation.Her BP was 99/58 mmHg and HR was 86 bpm an hour after intubation. Considering the presentation, a diagnosis of serotonin syndrome was made. She was left intubated and transferred to the surgical intensive care unit (SICU). The surgical team was requested to hold her antianxiety and antidepressant medications and asked not to administer fentanyl or ondansetron. She continued to receive ventilator

Postoperative unilateral facial oedema: a complication of acute flexion of the neck

A case report describing a complication following the use of the sitting position and an extreme flexed position of the neck is presented. The patient developed unilateral oedema of the face, tongue and soft tissues of the mouth. The trachea was reintubated and the oedema subsided without treatment. The cause of the oedema is believed to be obstruction of the venous drainage of the head and neck.RésuméOn rapporte une complication de la position assise avec flexion extreme du cou. Le patient a développé un oedème de la face, de la langue et des tissus mous de la bouche. On réintuba le patient et l’oedème régressa spontanément. On attribue cet oedème à une obstruction au drainage veineux de la tête et du cou.

Propofol in patients susceptible to malignant hyperthermia: A case report and review of the literature

Propofol is an intravenous (IV) drug recently introduced into the United States for induction and maintenance of anesthesia. In spite of extensive laboratory evaluation, it is not possible to predict all the potential side effects that might be associated with a new drug. Because malignant hyperthermia (MH) remains a serious and potentially life-threatening complication of anesthesia, all new anesthetic drugs should be considered potential triggering drugs until proven otherwise. We report the use of IV propofol for the induction and maintenance of general anesthesia in an MH patient and review the literature on this subject.

Anesthesia machine malfunction simulating spontaneous respiratory effort

We present a case in which a dip in the capnogram of an anesthetized patient, which may indicate clinical complications such as spontaneous respiratory effort, was caused by a malfunction of the anesthesia delivery system. The rubber diaphragm of the ventilator relief valve was found to be coated with a sticky substance which may have caused adhesion at the valve seat. This adhesion blocked the flow ot excess gas to the scavenging system during exhalation. It was demonstrated that a pressure of 5 cm H2O was needed to overcome this adhesion.We present a case in which a dip in the capnogram of an anesthetized patient, which may indicate clinical complications such as spontaneous respiratory effort, was caused by a malfunction of the anesthesia delivery system. The rubber diaphragm of the ventilator relief valve was found to be coated with a sticky substance which may have caused adhesion at the valve seat. This adhesion blocked the flow ot excess gas to the scavenging system during exhalation. It was demonstrated that a pressure of 5 cm H2O was needed to overcome this adhesion.

Pulmonary artery occlusion pressure is not accurate immediately after cardiopulmonary bypass

Elevated pulmonary vascular resistance (PVR), differential cardiac dynamics, and increased lung water following cardiopulmonary bypass (CPB) have been proposed as limitations to the accuracy of the pulmonary artery occlusion pressure (PAOP) in estimating left ventricular preload. A prospective study of 22 patients undergoing elective myocardial revascularization is described wherein PAOP was compared with directly measured left atrial pressure (LAP). The reliability of PAOP to estimate LAP in the hour immediately following CPB and at 1, 4, 8, and 12 hours post-CPB was examined with repeated measures analysis of variance. Relationships between the PAOP-LAP difference and PVR, core temperature, arterial CO2 tension, and right and left ventricular stroke work indices (RVSWI, LVSWI) were tested by linear regression analysis. There was greater variability in measurements at 15, 30, and 45 minutes immediately after CPB, demonstrated by a pooled correlation coefficient of 0.73 versus 0.90 in the postoperative period. The degree of discrepancy between PAOP and LAP lessened with time. There was no determinable relationship of the PAOP-LAP gradient to PVR, level of PCO2, temperature, RVSWI, or LVSWI. Potential sources of discrepancy include airway pressure effects, position of the measuring catheters, positive end-expiratory pressure, infusion of protamine sulfate, extremes of pulmonary artery pressures, and effects of an open pericardium.(ABSTRACT TRUNCATED AT 250 WORDS)

Perioperative retinoic acid syndrome in a patient with acute promyelocytic leukemia

All-trans retinoic acid (ATRA), a vitamin A derivative, is prescribed for induction of chemotherapy in patients with acute promyelocytic leukemia. Like other chemotherapy agents, ATRA has an adverse effect known as retinoic acid syndrome. The case of a 22 year old woman with acute promyelocytic leukemia, who received ATRA and subsequently developed retinoic acid syndrome, is presented. The patients symptoms resolved after administration of dexamethasone, allowing the completion of chemotherapy without further complications.

Mass spectrometer artifact: simultaneous detection of two volatile anesthetics.

In several cases, a mass spectrometer indicated that both enflurane and isoflurane were being detected while only isoflurane was in use. The concentration of expired enflurane reported was always higher than the inspired concentration, but never exceeded 0.66% regardless of the concentration of isoflurane. Such mass spectrometer readings may be evidence of vaporizer contamination or malfunction of the vaporizer; however, in this case, the mass spectrometer was found to be out of calibration. Because mass spectrometers are recent additions to clinical equipment, procedures for routine calibration and maintenance must be carefully scrutinized and evaluated.

Modification Of A Blanket Machine To Prevent Accidental Hypothermia Under Anesthesia

An emergency surgical procedure in which accidental excessive hypothermia was induced is described. Temperature drop at a rate greater than normal led to investigation which revealed improper setting of a hypo-hyperthermia machine. A simple and effective modification was made to the hypo-hyperthermia machines to reduce the likihood of the repetition of this event. Evaluation of the modified unit revealed no significant degradation of performance. Physiological effects of hypothermia are also described.