Treatment of
Hyperthermia
Idiopathic Malignant
To the Editor.\p=m-\Thearticle titled "Id-
iopathic Malignant Hyperthermia" by Justin A. Bergman, MD, that appeared in the Archives (93:232, 1975) provides a concise review of the pathophysiology of this disease. However, I should like to point out what I
consider to be an error in the treatment of the disease that Bergman presents in the case report. The primary biochemical abnormality in malignant hyperthermia is a high concentration of calcium in the myoplasm, probably from the sarcoplasmic reticulum. Hence, drugs that inhibit the uptake of calcium by the sarcoplasmic reticulum should not be used. As Britt has pointed out (N Engl J Med 290:1141, 1974), lidocaine and the cardiac glycosides are agents that extrude calcium from the sarcoplasmic reticulum, and so they never should be administered during crises of malignant hyperthermia. Procaine and procainamide are drugs that lower myoplasmic calcium levels by transporting calcium out of the myoplasm into the sarcoplasmic reticulum. They may be useful in the acute phase of the disease. So, if a regional anes¬ thetic technique is selected for a patient known to have malignant
hyperthermia or a strong family history of it, procaine should be used instead of lidocaine. George M.
Saviello, MD Gainesville, Fla
General Anesthesia in
Surgery
Ophthalmic
To the Editor.\p=m-\The article entitled "Intraocular Surgery With General
Anesthesia" by Wolf et al (The Archives 93:323, 1975) was designed as a prospective study of "the relative safety and benefits of local vs general anesthesia." While the authors were able to determine relative effects on ocular complications of sugery, the
study groups reported (2,217 patients receiving general anesthesia, 561 patients receiving local anesthesia) were not large enough to allow calculation of relative mortality risks of the two
modes of anesthesia. It could have been predicted from the data of previous retrospective studies1-8 that the mortality would approximate one death per 1,000 ophthalmic procedures. Corresponding to these expected rates, one patient died in the general anesthesia group of Wolf et al, and none died in the local anesthesia group. The prospective design and the control of characteristics of the two populations in the study by Wolf et al have definite advantages over retrospective study, and I hope that they will continue to add patients to the study for several more years in order to clarify this point. Previous pub¬ lished work has been conflicting, some authors1·7 suggesting that the mortali¬ ty risk for general anesthesia is higher than for local, while others agree with the tentative conclusion of Wolf et al that the two methods seem equally safe.1 In addition, general anesthesia has recently been asso¬ ciated with the malignant hyperther¬ mia syndrome"; further data would aid in assessing the risk of this infrequent but serious complication. In evaluating data on deaths after surgery, bed rest has been implicated as an important risk factor; it would
Downloaded From: http://archopht.jamanetwork.com/ by a University of Iowa User on 06/15/2015
be helpful to have data on this subject included in such studies, along with autopsy findings to establish the cause of death. Finally, the relative time (induc¬ tion, recovery) and cost (anesthesia and recovery room fees) involved in general anesthesia relative to local anesthesia might be considered in comparisons of the two methods. Harry Alan Quigley, MD Miami, Fla 1. Quigley HA: Mortality associated with ophthalmic surgery: A 20-year experience at the
Ophthalmol
Wilmer Institute. Am J 77:517-524, 1974. 2. Jayle GE, Boyer R, Aubert L, et al: La morte post-operatoire en ophtalmologie. Annee Ther Clin Ophtalmol 9:169, 1968. 3. Duncalf D, Gartner S, Carol B: Mortality in association with ophthalmic surgery. Am J Ophthalmol 69:610-615, 1970. 4. Gartner S, Billet E: A study on mortality rates during general anesthesia for ophthalmic surgery. Am J Ophthalmol 45:847-849, 1958. 5. Kristensen P: Causes of death among patients admitted to an ophthalmological ward. Acta Ophthalmol 44:169-179, 1966. 6. Strub F: Die Sterblichkeit in einer ophthalmologischen Klinik. Klin Monatsbl Augenheilkd 154:238-248, 1969. 7. Petruscak J, Smith RB, Breslin P: Mortality related to ophthalmological surgery. Arch Ophthalmol 89:106-109, 1973. 8. Kaplan MR, Reba RC: Pulmonary embolism as the leading cause of ophthalmic surgical mortality. Am J Ophthalmol 73:159-166, 1972. 9. Bergman JA: Idiopathic malignant hyperthermia: Review and report of a case. Arch Ophthalmol 93:232-234, 1975.
Computerized Axial Tomography in Patients With Exophthalmos To the Editor.\p=m-\It has come to our attention that unnecessary mistakes are being made in the evaluation of patients with unilateral exophthalmos using the EMI head scanner (devel-
Hyperthermia
Idiopathic Malignant
To the Editor.\p=m-\Thearticle titled "Id-
iopathic Malignant Hyperthermia" by Justin A. Bergman, MD, that appeared in the Archives (93:232, 1975) provides a concise review of the pathophysiology of this disease. However, I should like to point out what I
consider to be an error in the treatment of the disease that Bergman presents in the case report. The primary biochemical abnormality in malignant hyperthermia is a high concentration of calcium in the myoplasm, probably from the sarcoplasmic reticulum. Hence, drugs that inhibit the uptake of calcium by the sarcoplasmic reticulum should not be used. As Britt has pointed out (N Engl J Med 290:1141, 1974), lidocaine and the cardiac glycosides are agents that extrude calcium from the sarcoplasmic reticulum, and so they never should be administered during crises of malignant hyperthermia. Procaine and procainamide are drugs that lower myoplasmic calcium levels by transporting calcium out of the myoplasm into the sarcoplasmic reticulum. They may be useful in the acute phase of the disease. So, if a regional anes¬ thetic technique is selected for a patient known to have malignant
hyperthermia or a strong family history of it, procaine should be used instead of lidocaine. George M.
Saviello, MD Gainesville, Fla
General Anesthesia in
Surgery
Ophthalmic
To the Editor.\p=m-\The article entitled "Intraocular Surgery With General
Anesthesia" by Wolf et al (The Archives 93:323, 1975) was designed as a prospective study of "the relative safety and benefits of local vs general anesthesia." While the authors were able to determine relative effects on ocular complications of sugery, the
study groups reported (2,217 patients receiving general anesthesia, 561 patients receiving local anesthesia) were not large enough to allow calculation of relative mortality risks of the two
modes of anesthesia. It could have been predicted from the data of previous retrospective studies1-8 that the mortality would approximate one death per 1,000 ophthalmic procedures. Corresponding to these expected rates, one patient died in the general anesthesia group of Wolf et al, and none died in the local anesthesia group. The prospective design and the control of characteristics of the two populations in the study by Wolf et al have definite advantages over retrospective study, and I hope that they will continue to add patients to the study for several more years in order to clarify this point. Previous pub¬ lished work has been conflicting, some authors1·7 suggesting that the mortali¬ ty risk for general anesthesia is higher than for local, while others agree with the tentative conclusion of Wolf et al that the two methods seem equally safe.1 In addition, general anesthesia has recently been asso¬ ciated with the malignant hyperther¬ mia syndrome"; further data would aid in assessing the risk of this infrequent but serious complication. In evaluating data on deaths after surgery, bed rest has been implicated as an important risk factor; it would
Downloaded From: http://archopht.jamanetwork.com/ by a University of Iowa User on 06/15/2015
be helpful to have data on this subject included in such studies, along with autopsy findings to establish the cause of death. Finally, the relative time (induc¬ tion, recovery) and cost (anesthesia and recovery room fees) involved in general anesthesia relative to local anesthesia might be considered in comparisons of the two methods. Harry Alan Quigley, MD Miami, Fla 1. Quigley HA: Mortality associated with ophthalmic surgery: A 20-year experience at the
Ophthalmol
Wilmer Institute. Am J 77:517-524, 1974. 2. Jayle GE, Boyer R, Aubert L, et al: La morte post-operatoire en ophtalmologie. Annee Ther Clin Ophtalmol 9:169, 1968. 3. Duncalf D, Gartner S, Carol B: Mortality in association with ophthalmic surgery. Am J Ophthalmol 69:610-615, 1970. 4. Gartner S, Billet E: A study on mortality rates during general anesthesia for ophthalmic surgery. Am J Ophthalmol 45:847-849, 1958. 5. Kristensen P: Causes of death among patients admitted to an ophthalmological ward. Acta Ophthalmol 44:169-179, 1966. 6. Strub F: Die Sterblichkeit in einer ophthalmologischen Klinik. Klin Monatsbl Augenheilkd 154:238-248, 1969. 7. Petruscak J, Smith RB, Breslin P: Mortality related to ophthalmological surgery. Arch Ophthalmol 89:106-109, 1973. 8. Kaplan MR, Reba RC: Pulmonary embolism as the leading cause of ophthalmic surgical mortality. Am J Ophthalmol 73:159-166, 1972. 9. Bergman JA: Idiopathic malignant hyperthermia: Review and report of a case. Arch Ophthalmol 93:232-234, 1975.
Computerized Axial Tomography in Patients With Exophthalmos To the Editor.\p=m-\It has come to our attention that unnecessary mistakes are being made in the evaluation of patients with unilateral exophthalmos using the EMI head scanner (devel-
